System and method for controlling engine operation to support external electrical loads
阅读说明：本技术 用于控制发动机操作以支持外部电负载的系统和方法 (System and method for controlling engine operation to support external electrical loads ) 是由 斯图尔特·索尔特 罗斯·戴卡斯特拉·普西福尔 保罗·肯尼士·戴尔洛克 威廉·泰勒 大卫·布莱 于 2020-03-25 设计创作，主要内容包括：本公开提供了“用于控制发动机操作以支持外部电负载的系统和方法”。提供了用于控制车辆的发动机的操作以向电源箱供电的方法和系统,所述电源箱进而向所述车辆外部的负载供电。在一个示例中,一种方法包括：响应于操作员所作的操作发动机以向所述车辆外部的一个或多个负载供电的请求,监测发动机温度,并且在所述发动机温度达到阈值温度时发出请求所述操作员采取缓解动作以降低所述发动机温度的警示；以及根据是否采取了所述缓解动作来控制冷却风扇。以此方式,可改善燃料经济性并且可优化用于向外部负载供电的电力供应。(The present disclosure provides "systems and methods for controlling engine operation to support an external electrical load". Methods and systems are provided for controlling operation of an engine of a vehicle to supply power to a power supply box, which in turn supplies power to a load external to the vehicle. In one example, a method comprises: in response to a request by an operator to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing an alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a threshold temperature; and controlling the cooling fan depending on whether the mitigating action is taken. In this way, fuel economy may be improved and the supply of electrical power for powering an external load may be optimized.)
1. A method, comprising:
in response to a request by an operator of a vehicle to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing a first alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a first threshold temperature; and
controlling the cooling fan depending on whether the mitigating action is taken.
2. The method of claim 1, wherein the first threshold temperature comprises 50 ° f.
3. The method of claim 1, wherein the first threshold temperature comprises a temperature in a range of 40F to 60F.
4. The method of claim 1, wherein the request by the operator to operate the engine to power one or more loads external to the vehicle further comprises the vehicle being stationary.
5. The method of claim 1, wherein the first alert requesting the operator to take mitigating action to reduce the engine temperature comprises a request to open a hood of the vehicle.
6. The method of claim 1, wherein controlling the cooling fan based on whether the mitigation action was taken further comprises: maintaining the cooling fan shut down in response to the mitigating action having been taken; and
activating the cooling fan in response to the mitigation action not having been taken.
7. The method of claim 1, wherein controlling the cooling fan based on whether the mitigation action was taken further comprises: controlling the cooling fan at a first speed of rotation in response to the mitigating action having been taken; and
controlling the cooling fan at a second rotational speed in response to the mitigating action not having been taken, wherein the first rotational speed is lower than the second rotational speed.
8. The method of claim 1, wherein in response to an indication that the engine temperature has reached a second threshold temperature greater than the first threshold temperature:
maintaining power to a first set of outlets that supply power to the one or more external loads; and interrupting the supply of power to a second set of outlets supplying power to the one or more external loads.
9. The method of claim 8, wherein the first set of outlets comprises outlets that supply a first voltage, and wherein the second set of outlets comprises outlets that supply a second voltage, wherein the first voltage is lower than the second voltage.
10. The method of claim 8, further comprising:
in response to reaching a third threshold temperature that is greater than the second threshold temperature, discontinuing the supply of power to the first set of outlets that supply power to the one or more external loads.
11. A system for a vehicle, comprising:
an engine capable of driving a generator to provide power to a power box, which in turn supplies power to one or more external loads;
one or more temperature sensors for monitoring engine temperature;
a warning system for communicating a visual and/or audible warning to an operator of the vehicle; and
a controller having computer readable instructions stored on non-transitory memory that, when executed while the vehicle is stationary and in a parked state and while the engine combusts air and fuel to provide power to the power supply box for powering the one or more external loads, cause the controller to:
monitoring the engine temperature via the one or more temperature sensors; and
in response to the engine temperature reaching a first threshold temperature, issuing a first alert requesting the operator of the vehicle to take a mitigating action to reduce the engine temperature while maintaining power to the one or more external loads.
12. The system of claim 11, wherein the mitigating action comprises opening a hood of the vehicle.
13. The system of claim 11, wherein the one or more temperature sensors monitor cylinder head temperature of one or more cylinders of the engine, and wherein the one or more temperature sensors are communicatively coupled to one or more circuit breakers of one or more outlets of the power supply box, the one or more outlets including a first set of outlets and a second set of outlets; and
wherein the controller stores further instructions for: maintaining power to the first set of outlets while discontinuing provision of power to the second set of outlets in response to the engine temperature reaching a second threshold temperature greater than the first threshold temperature, and discontinuing provision of power to the first set of outlets in response to the engine temperature reaching a third threshold temperature greater than the second threshold temperature.
14. The system of claim 13, wherein when the engine temperature is within a first threshold degree of the second threshold temperature, a second alert is issued to notify the operator that power to the second set of outlets is about to be interrupted, and wherein when the engine temperature is within a second threshold degree of the third threshold temperature, a third alert is issued to notify the operator that power to the first set of outlets is about to be interrupted.
15. The system of claim 11, further comprising a fan for cooling the engine, and wherein the controller stores further instructions for:
differentially controlling the speed of the cooling fan depending on whether the mitigating action has been taken to reduce the engine temperature.
Technical Field
The present description relates generally to methods and systems for controlling engine operation when the engine is used to support an external electrical load, particularly where the engine is breathing un-metered exhaust gases.
Background
In some examples, passenger cars, light trucks, and heavy duty trucks may include the capability to support 110V-120V Alternating Current (AC) electrical loads and 220V-240V AC electrical loads. As one example, such vehicles may support electrical loads up to about 450 watts, and in the future may support electrical loads of 2KW-8KW and potentially higher (e.g., 16KW and greater). Systems for such vehicles may include designs for directly supporting such appliances (e.g., for use at a workplace or for supplying power to a home electrical load) when the vehicle is stationary or for directly supporting such appliances (e.g., supplying power to a refrigeration unit) when the vehicle is moving. Such systems may include Direct Current (DC) to AC systems, and may be referred to as "power to tank (PttB)" systems. Such PttB systems may be driven by an alternator, a belt-driven starter generator (BISG) driven by the engine, or a high voltage battery (e.g., 300V-350V) which is in turn charged by the crank isg (cisg).
However, the inventors herein have recognized that the supply of electrical power to the external load may be compromised by engine overheating and/or alternator/generator heating. While the use of cooling fans may help reduce the rate at which the engine and/or alternator/generator temperature increases, cooling fans require significant electrical power to operate, and thus relying solely on such fans may adversely affect the fuel economy of a vehicle often used to power one or more external loads.
Disclosure of Invention
The inventors herein have developed systems and methods that at least partially address the above-mentioned problems. In one example, a method comprises: in response to a request by an operator of a vehicle to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing a first alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a first threshold temperature; and controlling the cooling fan according to whether the mitigating action is taken. In this way, mitigation actions may be used to control engine temperature when the engine is used to power one or more external loads, rather than operating a cooling fan. Therefore, fuel economy can be improved.
As one example, the first alert requesting the operator to take mitigating action to reduce the engine temperature may include a request to open a hood of the vehicle. Controlling the cooling fan may include: maintaining the cooling fan off in response to the mitigating action having been taken, and enabling the cooling fan in response to the mitigating action not having been taken.
In another example, controlling the cooling fan according to whether the mitigating action is taken may further include: controlling the cooling fan at a first speed in response to the mitigating action having been taken, and controlling the cooling fan at a second speed in response to the mitigating action not having been taken, wherein the first speed is lower than the second speed.
The above advantages and other advantages and features of the present description will be readily apparent from the following detailed description when considered in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. This is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
Drawings
FIG. 1 schematically illustrates an exemplary vehicle propulsion system.
FIG. 2 schematically illustrates an exemplary vehicle system having a fuel system, an evaporative emissions system, and an engine system including an EGR system.
FIG. 3 depicts a high level flow chart of an exemplary method for learning when to infer the use of the PttB system in situations where unmetered EGR may be introduced into an engine.
FIG. 4 depicts a high level flow chart of an exemplary method for controlling engine operation in response to an indication that a vehicle is operating in PttB mode if it is inferred that unmetered EGR is introduced into the engine.
FIG. 5 depicts a high level flow chart of a first exemplary method for determining an unmetered EGR level introduced into an engine when a vehicle is operating in PttB mode.
FIG. 6 depicts a high level flow chart of a second exemplary method for determining an unmetered EGR level introduced into an engine when a vehicle is operating in PttB mode.
FIG. 7 depicts a high level flow chart of a third exemplary method for determining an unmetered EGR level introduced into an engine when a vehicle is operating in PttB mode.
FIG. 8 depicts an exemplary timeline for controlling engine operation in response to an indication that a vehicle is operating in PttB mode if it is inferred that unmetered EGR is introduced into the engine in accordance with the method of FIG. 4.
FIG. 9 depicts a high-level flow chart of an exemplary method for monitoring engine temperature while a vehicle is operating in PttB mode and taking mitigating action in response to certain temperature thresholds being met or exceeded.
FIG. 10 depicts a high level flow chart of an exemplary method for controlling engine operation via the methods of FIGS. 4 and 9.
FIG. 11 depicts an exemplary timeline for controlling engine operation according to FIG. 10.
FIG. 12 depicts an exemplary real-time display for communicating various parameters determined via the methods depicted herein to a vehicle operator.
Detailed Description
The following description relates to systems and methods for controlling operation of an engine for supplying power to an external load (referred to herein as a supply-to-tank mode or PttB mode), particularly when it is determined that the engine is operating in a space with limited air flow (referred to herein as a reduced air exchange condition). For example, a space with restricted air circulation may include a garage (with doors closed or even open) or other enclosed or partially enclosed space. The reduced air exchange condition as discussed herein relates to a condition where operation of the engine may result in an increase in exhaust gas concentration in the air near the vehicle. For example, the vicinity of the vehicle may include air around the vehicle. Additionally or alternatively, the vicinity of the vehicle may include a space within a predetermined distance from the vehicle in any direction. For example, the predetermined distance may include 10 feet or less, 20 feet or less, 30 feet or less, 40 feet or less, and the like. The condition of reduced air exchange may include any situation where the exhaust gas introduced into the engine through the intake passage increases over time with engine operation. In other words, conditions of reduced air exchange include situations where exhaust gas drawn into the engine as air is drawn into the engine increases over time with continued engine operation, rather than being intentionally routed to the engine through the exhaust gas recirculation system. It will be appreciated that as the level of unmetered exhaust gas introduced into the engine increases, engine stability issues (e.g., sluggish, stalling, knocking, etc.) may be compromised, which in turn may adversely affect the power supplied to the power supply box.
Accordingly, vehicle systems, such as the vehicle system depicted in fig. 1, including an on-board power supply box that may receive power from engine operation are discussed herein. The methods discussed herein relate to evaluating the level of unmetered Exhaust Gas Recirculation (EGR) introduced into an engine, and thus take into account the amount of EGR intentionally introduced into the engine via an EGR system as depicted in FIG. 2. In some examples, the reduced air exchange condition may be indicated based on GPS satellite signals, vehicle-to-vehicle (V2V), and/or vehicle-to-infrastructure (V2I) loss, and/or based on learned travel routines over time. Thus, a method for learning a travel routine is depicted at fig. 3.
FIG. 4 depicts an exemplary method for determining whether a request by a vehicle operator to operate the vehicle in PttB mode is made under reduced air exchange conditions. If so, the level of unmetered EGR introduced to the engine may be determined by any of the methods depicted in FIGS. 5-7. Based on the unmetered EGR level, mitigating actions may be taken to control engine operation to account for such unmetered EGR in accordance with the method of FIG. 4. Such actions include one or more of the following operations: controlling a duty cycle of the EGR valve based on the determined unmetered EGR level, controlling spark timing, issuing a visual and/or audible alert to a vehicle operator of an impending engine shut-off, and the like. Depicted at fig. 8 is a timeline for controlling engine operation based on the methods of fig. 4-7.
It is further recognized that as engine temperature increases, the power output to the power supply box (via the generator/alternator, etc.) may decrease. Accordingly, another object of the present disclosure is a method for monitoring engine temperature and controlling engine operation and thus power supply box operation as a function of engine temperature. This approach is depicted at fig. 9. The method of fig. 9 may be used in the case where PttB mode is used but not in the condition of reduced air exchange, or alternatively may be used when PttB mode is used in the condition of reduced air exchange. Thus, fig. 10 depicts an exemplary method that takes into account the methods of fig. 4-7 and 9. An exemplary timeline for controlling engine operation according to FIG. 10 is depicted at FIG. 11.
Because one or more of the unmetered exhaust gas and/or engine temperature introduced to the engine may contribute to degradation of the PttB mode (e.g., less efficient power supply to an external load, inconsistent power supply to an external load, etc.), it is recognized herein that it may be desirable to provide a vehicle operator with access to a number of real-time parameters related to engine operation in the PttB mode, including but not limited to: the level of unmetered exhaust gas introduced to the engine, the engine temperature, the current power output from the power supply box, an "elapsed fuel time to travel" indicator used to alert the vehicle operator how much time before the fuel tank runs out of fuel (rather than the number of miles the fuel may travel since the vehicle may be operating while stationary), engine speed, and the like. Such real-time parameters may be determined via a controller of the vehicle and sent to a real-time display for viewing on a screen associated with the vehicle dashboard (e.g., a Ford Sync screen) or on a computing device used by the vehicle operator (such as a smartphone, laptop, tablet computer, etc.). For example, the real-time display may include a software application that communicates with the vehicle controller for updating the real-time parameters. Such a real-time display may also include a message center for alerting the vehicle operator when certain thresholds related to unmetered EGR, engine temperature, etc. have been reached or exceeded. An example of such a real-time display is depicted at fig. 12.
FIG. 1 illustrates an exemplary
The
During other conditions,
During still other operating conditions,
In other embodiments, the
The
The
In some embodiments, the
The
The
In other embodiments, the electrical transmission cable 182 may be omitted, wherein electrical energy may be received wirelessly from the power source 180 at the
The
The
In some examples,
Further, the
Turning now to fig. 2, a schematic depiction of a
The
An intake system hydrocarbon trap (AIS HC)224 may be placed in an intake manifold of
In some examples, the
The
In some examples,
The
One or
The
A
Each of the engine cylinders 230 may include a
Vapors generated in the
Additionally, in some examples, one or more tank vent valves may be positioned in conduits 271, 273, or 275. Among other functions, the fuel tank vent valve may allow for maintaining a fuel vapor canister of an emissions control system at a low pressure or vacuum without increasing the rate of evaporation of fuel from the tank (which would otherwise occur if the fuel tank pressure were reduced). For example, conduit 271 may include a Grade Vent Valve (GVV)287, conduit 273 may include a Fill Limit Vent Valve (FLVV)285, and conduit 275 may include a Grade Vent Valve (GVV) 283. Additionally, in some examples, the
Additionally, the refuel
In some embodiments, refuel
In some embodiments, refuel
In embodiments where an electric mechanism is used to lock the refuel
The canister 222 may include a
In some examples, the flow of air and vapor between canister 222 and the atmosphere may be regulated by a
The controller 212 may form part of the
The
The
The controller 212 may be coupled to the
The controller 212 may be communicatively coupled to other vehicles or infrastructure using suitable communication techniques as are known in the art. For example, the
The
As discussed above, the
Accordingly, the system for a vehicle discussed herein may include an engine that may drive a generator for providing power to a power supply box that in turn supplies power to one or more external loads. Such a system may further comprise: one or more temperature sensors for monitoring engine temperature; and a warning system for conveying a visual and/or audible warning to an operator of the vehicle. For such a system, the system may further include a controller having computer readable instructions stored on non-transitory memory that, when executed while the vehicle is stationary and in a parked state and while the engine is combusting air and fuel to provide power to the power supply box to power the one or more external loads, cause the controller to: monitoring the engine temperature via the one or more temperature sensors, and in response to the engine temperature reaching a first threshold temperature, issuing a first alert requesting the operator of the vehicle to take mitigating action to reduce the engine temperature while maintaining power to the one or more external loads.
For such systems, the one or more temperature sensors may monitor cylinder head temperature of one or more cylinders of the engine. The one or more temperature sensors may be one or more circuit breakers communicably coupled to one or more outlets of the power supply box, the one or more outlets including a first set of outlets and a second set of outlets. In such a system, the controller may store further instructions for: in response to the engine temperature reaching a second threshold temperature greater than the first threshold temperature, maintaining power to the first set of outlets while discontinuing provision of power to the second set of outlets; and in response to the engine temperature reaching a third threshold temperature greater than the second threshold temperature, discontinuing provision of electrical power to the first set of outlets. In such an example, a second alert may be issued to notify the operator that power to the second set of outlets is about to be interrupted when the engine temperature is within a first threshold degree of the second threshold temperature, and wherein a third alert may be issued to notify the operator that power to the third set of outlets is about to be interrupted when the engine temperature is within a second threshold degree of the third threshold temperature.
For such a system, the system may further comprise a fan for cooling the engine, and wherein the controller stores further instructions for: differentially controlling the speed of the cooling fan depending on whether the mitigating action has been taken to reduce the engine temperature, wherein the mitigating action includes opening a hood of the vehicle.
Turning now to FIG. 3, a high level
The
The
Returning to 305, in response to indicating a key-on event,
Proceeding to 320, the
As one example, the data acquired by the controller at 320 may include information regarding whether PttB mode is requested via the vehicle operator when at or near a particular location. The data may include the time of day (and the day of the week/month) that the PttB mode is requested, and may also include the length of time that the particular PttB mode request is sustained. In other words, the duration of the PttB mode may be obtained. In some examples, the data may include information related to inferring whether or not unmetered EGR is drawn into the engine when the vehicle is operating in PttB mode at or near a particular location. As discussed herein, it may be appreciated that the unmetered EGR includes exhaust gas introduced into the engine through an intake passage (e.g., 242), where the unmetered EGR is introduced into the intake passage upstream of a throttle (e.g., 262). In contrast, EGR as discussed herein, introduced into the intake manifold (e.g., 244) through an EGR system (e.g., 249) and under control of an EGR valve (e.g., 253) can be understood to include metered EGR.
More specifically, unmetered EGR may be drawn into the engine in situations where air exchange near the vehicle is reduced (such as may occur when the vehicle is operating in PttB mode, for example, in an enclosed space). In such an example, it can be appreciated that a reduction in GPS satellite signals can result when the vehicle enters such a location where air exchange is reduced. Thus, via the method of FIG. 3, the controller may learn a particular position where it is inferred that the vehicle has entered a setting where air exchange reduction is likely or expected, and where it is likely that it will be requested to operate the vehicle in PttB mode. Thus, in such an example, in response to a request for PttB mode, where PttB mode is dependent on engine operation, engine operation may be controlled as discussed in further detail below with respect to the methods of FIGS. 4-7 to avoid undesirable problems associated with ingesting unmetered EGR when operating in PttB mode in a reduced air exchange position.
Thus, data regarding a particular vehicle travel route or other relevant information (e.g., locations where PttB mode air exchange reduction is frequently requested) may be obtained and stored at the vehicle controller. Proceeding to 325, the
For example, numerous travel routes and corresponding information may be obtained and stored at a vehicle controller such that a predicted/learned travel route and associated action (e.g., a requested PttB mode of operation) may be obtained with a high degree of accuracy. In some examples, the vehicle may travel along a route that is not traveled frequently (e.g., not "commonly used"). Thus, it can be appreciated that route information that is not significantly related to a route that is normally traveled can be periodically forgotten or removed from the vehicle controller in order to prevent an excessive amount of data related to the vehicle travel routine from accumulating.
In some examples, data collected from vehicle travel routines (including GPS data) may be applied to algorithms that feed into one or more machine learning algorithms to determine common vehicle travel routes and other relevant information (e.g., PttB mode requests, and whether such requests are consistent with engine operation in locations with reduced air exchange).
Thus, learning the travel route at 325 may include: a particular travel route (or key-on event where the vehicle is not traveling) associated with the PttB use request is determined. As one example, a vehicle operator may drive the vehicle to a work site, and may request PttB mode at a particular work site in a fairly frequent manner. Thus, the controller may process data associated with the acquired information relating to the particular workplace and PttB mode request to establish whether PttB mode is likely to be requested in the event of a reduced air exchange near the vehicle (which may result in the engine ingesting an unmetered EGR).
In some examples, such a likelihood may include several different confidence estimates. For example, given a particular location where the vehicle is located, it is highly likely that PttB mode will be requested with reduced air exchange in the vicinity of the vehicle. In other examples, given a particular location of the vehicle, the likelihood of requesting PttB mode with reduced air exchange near the vehicle is medium or low. The likelihood may be based on empirically obtained data. For example, the greater the number of times the vehicle operator requests PttB mode with reduced air exchange at a particular location, the higher the likelihood that PttB mode will be requested when the vehicle is in such a location. Such possibilities may be used with the methods of fig. 4-7 to control engine operation under such circumstances, as will be discussed in further detail below.
Proceeding to 330, the
Thus, turning now to FIG. 4, a high level exemplary method 400 for controlling engine operation in situations where PttB mode has been requested and it is further inferred that the vehicle is in a reduced air exchange position is shown. More specifically, the method 400 may be used to: in response to an indication of engine operation under the inferred reduced air exchange condition, an input is requested from an operator as to whether it is desired to continue such engine operation. In the absence of such operator input, engine shut-off may be controlled under control of a vehicle controller, while in response to such operator input, engine operation may continue with unmetered EGR drawn into the engine may be monitored and compensated for. In response to an indication that the amount of unmetered exhaust gas drawn into the engine exceeds a first threshold, an alert may be provided to a vehicle operator indicating that the engine will be shut down unless mitigating action is taken. Then, in the absence of such mitigating action, the engine may be controlled to shut off under control of the vehicle controller in response to an indication that unmetered exhaust gas drawn into the engine exceeds a second threshold amount. It is appreciated that controlling the engine off may include: fuel and spark to the engine cylinder are discontinued.
The method 400 will be described with reference to the systems described herein and shown in fig. 1-2, but it should be understood that similar methods may be applied to other systems without departing from the scope of the present disclosure. The method 400 may be implemented by a controller (such as the controller 212 in fig. 2) and may be stored as executable instructions in a non-transitory memory at the controller. The instructions for implementing the method 400, as well as the remaining methods included herein, may be executed by the controller based on instructions stored on a memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to fig. 1-2. The controller may employ actuators such as one or more spark plugs (e.g., 298), one or more fuel injectors (e.g., 266), an EGR valve (e.g., 253), etc. to alter the state of devices in the physical world according to the methods depicted below.
The method 400 begins at 405 and includes: vehicle operating conditions are estimated and/or measured. The operating conditions may be estimated, measured, and/or inferred, and may include: one or more vehicle conditions, such as vehicle speed, vehicle location, etc.; various engine conditions such as engine state, engine load, engine speed, air-fuel ratio, manifold air pressure, etc.; various fuel system conditions such as fuel level, fuel type, fuel temperature, etc.; various evaporative emissions system conditions, such as fuel vapor canister loading, fuel tank pressure, etc.; and various environmental conditions such as ambient temperature, humidity, atmospheric pressure, and the like.
Proceeding to 410, the method 400 may include: indicating whether a condition for alerting a vehicle operator to a potentially controlled engine shut-down is satisfied. Satisfying the condition at 410 may include one or more of the following. In one example, satisfying the condition at 410 may include: an indication that the vehicle speed is below a threshold vehicle speed (e.g., stopped or stationary) with the engine in operation combusting air and fuel and with an indication that the vehicle is in a reduced air exchange position. In this example, and any other examples that rely on an indication that the vehicle is in a location with reduced air exchange, it will be appreciated that such an indication may include a reduction in GPS satellite signals when the vehicle is about to stop or after the vehicle has stopped. As one example, if 12 GPS satellite signals are indicated via the on-board navigation system, and the number is reduced by a threshold number (e.g., by three or more GPS signals) when the vehicle is about to stop or after the vehicle has stopped, a reduced air exchange condition may be indicated. Additionally or alternatively, such examples of the vehicle being in a location of reduced air exchange may be provided via a route learning method as discussed above with respect to fig. 3. More specifically, based on the learned route that the vehicle typically travels, inferences can be made regarding whether the vehicle has entered a condition for reduced air exchange.
In yet another example, detecting that the vehicle is in a reduced air exchange location may involve communication between the vehicle and other vehicles or infrastructure via V2V and/or V2I communication. For example, the vehicle may initiate a query via the controller as to whether the vehicle is in a reduced air exchange condition, and may receive a response from one or more vehicles and/or infrastructure as to whether the vehicle is in a reduced air exchange location.
Additionally or alternatively, satisfying the condition at 410 may include: an indication of a request to operate the vehicle in PttB mode in which power is supplied by the engine to the power supply box, and further in response to an indication that the vehicle is in a reduced air exchange position, as discussed above. For example, a vehicle operator may request the PttB mode through a screen associated with the vehicle dashboard, via a particular actuator (e.g., a button) associated with the vehicle dashboard and dedicated to communicating a request for PttB operation to a controller, and so forth. As another example, satisfying the condition at 410 may include: an indication that the vehicle speed has remained below a threshold vehicle speed (e.g., has stopped) for a predetermined duration with the engine operating and/or in the requested PttB mode, and further in response to an indication that the vehicle is in a reduced air exchange condition.
If such a condition is not indicated to be satisfied at 410, method 400 may proceed to 415. At 415, the method 400 may include: current vehicle operating parameters are maintained. For example, if the engine is in operation to combust air and fuel, such operation may be maintained. Alternatively, if the vehicle is propelled via electrical energy, such operation may be maintained. In examples where PttB mode/PttB mode is requested to be in operation but conditions are not met that alert the vehicle operator to a potentially controlled engine shut-down, then PttB mode may be continued so that power to the external load may be uninterrupted. The method 400 may then end.
Returning to 410, in response to a condition being met for alerting a vehicle operator of a potentially controlled engine shut-off, method 400 may proceed to 420. At 420, the method 400 may include: such alerts are provided, wherein such alerts further include a request for vehicle operator input. In other words, such alerts may include messages communicated to the vehicle operator that the vehicle may be operating with reduced air exchange, and may also include requests for vehicle operator input to maintain or continue such operation. Such a message may also include an indication that the engine will be scheduled to be shut down if such operator input is not received within a threshold duration (e.g., within 3 minutes or less, within 2 minutes or less, within 1 minute or less, etc.).
Examples of such messages may include messages communicated in the form of text-based messages via a vehicle dashboard (e.g., 196). As one example, there may be a separate screen associated with the vehicle dashboard (e.g., a Ford Sync screen) that may be used to provide such messages. In another example, such messages may include audible messages that are under the control of the controller and communicated via one or more speakers associated with the vehicle dashboard. In such an example, the controller may string together several keywords or phrases stored as a table at the controller to produce an audible message. Such audible messages may be provided via the dashboard in addition to or instead of text-based messages.
In another example, such messages may additionally or alternatively include text messages sent to software applications used by the vehicle operator (e.g., a smart phone application, a tablet computer application, etc.), and/or text messages sent to the vehicle operator's phone (e.g., a smart phone).
In still other examples, such messages may additionally or alternatively include a controller of the vehicle commanding a particular sequence of horn rings (e.g., five rings in rapid succession, etc.) and/or a particular sequence of exterior and/or interior light flashes. Other audible alerts are also within the scope of the present disclosure.
Subsequent to providing such an alert at 420, method 400 may proceed to 425 where a determination is made as to whether an operator input has been received in response to the alert at 425. Receiving operator input may include one or more of the following examples. One example may include: the vehicle operator depresses one of the accelerator pedal or the brake pedal in a particular pattern. In another example, receiving the operator input may include: the vehicle operator depresses the accelerator pedal first and then the brake pedal (or vice versa) in a certain predetermined alternating sequence. Other examples may include: the vehicle operator presses a button associated with the power seat (which may include pressing the buttons in a particular identifiable order), presses a particular button associated with a door of the vehicle (which may include pressing the buttons in a particular identifiable order), presses one or more buttons associated with a steering wheel of the vehicle (which may include pressing the one or more buttons in a particular identifiable order), interacts with a touch screen associated with a dashboard of the vehicle (e.g., a Ford Sync screen), responds to a text message including an alert requesting input by the vehicle operator, responds via a software application as discussed above, or via any other wireless communication system communicatively coupled to a controller of the vehicle and configured to receive such a response.
As discussed above, the engine may be controlled to shut down if such operator input is not received within a threshold duration (e.g., within 3 minutes or less, within 2 minutes or less, within 1 minute or less, etc.). In another example where PttB mode has been requested and one or more external loads have been plugged into the power box, if one or more loads are unplugged before a threshold duration has elapsed, engine shut-off may be controlled without vehicle operator input in the form described above. In other words, the pull-out of one or more external loads may be used as an indication that the vehicle operator does not wish to continue PttB mode given an alert and thus may shut down the engine. It will be appreciated that such an engine shut-down may occur when all external loads are pulled from the power supply box.
Thus, in such a case where no operator input is received (or when all external loads have been pulled out before the threshold duration has elapsed), method 400 may proceed to 430. At 430, the method 400 may include: engine operation is interrupted after the predetermined duration has elapsed. The predetermined duration may allow the vehicle operator to respond and avoid engine shut-down in case the vehicle operator desires engine operation to continue but does not respond within the time allotted at step 425. In some examples, the predetermined duration at 430 may include 15 seconds, 30 seconds, 45 seconds, 1 minute, and so forth.
Thus, proceeding to 435, method 400 may include: indicating whether a predetermined duration has elapsed (after which the engine will be shut off). If not, the method 400 may continue to determine if there is an operator input, and if not and the predetermined duration has elapsed, the method 400 may proceed to 440, at 440, an engine shut-off may be implemented. Specifically, the engine shut-off may include: the vehicle controller commands the fuel injector (e.g., 266) to stop providing fuel to the engine cylinder, and may further include: the provision of spark to the engine cylinder is discontinued. The method 400 may then end. It is to be appreciated that although not specifically shown in the flow description stemming from 435, the method 400 may return to 425 if the predetermined duration has not elapsed and the vehicle operator input is received.
Returning to 425, in response to having received a vehicle operator input as discussed, and further in response to requesting PttB mode, method 400 may proceed to 445. At 445, the method 400 may include: the engine is controlled in a speed feedback mode, wherein engine speed is maintained substantially constant, and a load on the engine is determined based on a total torque load on the engine from one or more sources. Other feedback modes for operation in PttB mode are also within the scope of the present disclosure.
Potential sources of load contributing to the total torque load may include engine pumping friction due to operation of the engine oil pump and the transmission oil pump (provided that the transmission oil pump is driven by the engine). Another potential load source may include a front-end accessory drive (FEAD) load. Examples of FEAD loads may include a 12V alternator (if present), and in some examples may include a higher voltage BISG (if present). In some examples, the FEAD load may include a 12V or 24V (or higher voltage) alternator or BISG to support PttB electrical loads. Another example of a FEAD load may include a water pump (provided that the pump is mechanically driven) and an AC compressor load (provided that the compressor is mechanically driven).
In some examples, the vehicle may be equipped with a CISG. In such an example, the CISG load may contribute to the total torque load when the vehicle is operating in PttB mode. In one example, the CISG may be connected to the crankshaft output through a disconnect clutch, and the CISG may operate at the same rotational speed as the crankshaft output, or in other examples, may operate at a higher rotational speed due to gearing between the disconnect clutch output and the CISG input. Where a disconnect clutch is employed, the torque load applied by the disconnect clutch to the engine may vary depending on the applied clutch pressure when the disconnect clutch is not locked, such as where slip across the disconnect clutch is greater than zero. Alternatively, in another example, where the disconnect clutch has locked or otherwise has zero slip, the torque load applied to the engine may vary depending on the CISG charging torque plus any additional load on the CISG output, such as mechanical transmission oil pump torque (provided such a pump is driven by the CISG).
As part of the engine calibration process before the vehicle operator uses the vehicle, the engine fresh air charge (e.g., air charge without any additional EGR) may be mapped based on the operating load and speed in the dynamometer test unit. For vehicles equipped with an EGR system (e.g., 249 depicted at fig. 2), EGR and spark timing may be scanned at the above-mentioned load and speed points in order to determine a maximum EGR at which the engine may operate at such load and speed points, as well as spark timing that provides a desired combination of fuel economy and combustion stability at such load and speed points. Specifically, it can be appreciated that EGR is introduced into the engine for at least the following purposes: 1) increasing intake manifold pressure to reduce engine pumping losses (which may reduce fuel consumption), and 2) adding combusted gases to the cylinder air charge, which may reduce cylinder combustion temperatures and thereby reduce NOx emissions, particularly where the EGR system includes a cooler (e.g., 289) to reduce EGR gas temperatures.
For an operating engine having an EGR system, the EGR measurement system may be used to calculate EGR mass flow rate (m) in real time, as discussed with respect to the method of FIG. 4egr). The total air charge mass flow rate (m) may then be determined fromtac) Subtract this EGR mass flow rate to determine a fresh air flow rate (m)fac) The fresh air flow rate may then be used for open loop engine fuel mass injection calculations and engine torque calculations.
For a given engine load (e.g., engine supported load or torque) and engine speed, there may be a map to the fresh air mass flow rate, as determined in dynamometer testing. The gas engine combustion torque for a 720 Crank Angle (CA) cycle may be given by:
(equation 1) Torque ═ mfnf*QHV/(4π)
(equation 2) mf＝mfac(A/F)
(equation 3) mtac＝Pman(nv*Vd/R*Tman)
(equation 4) mtac＝mfac+megr
(equation 5) mtac_th＝mfac+megr_th
(equation 6) megr＝megr_th+megr_meas
For equations 1-6 above:
nffuel conversion efficiency
nvVolumetric efficiency
QHVCombustion heat value
mfMass of injected fuel in Kg for a 720 degree CA cycle
mfacFresh air mass or charge introduced into the cylinder in Kg over a 720 degree CA cycle
mtacMass of total air mass (fresh air plus EGR) inducted into the engine, or in other words total air charge, in Kg over the 720 degree CA cycle
mtac_thMass in Kg of total air mass (fresh air plus EGR) inducted into the intake manifold from the throttle over 720 degrees CA cycle
megrEGR mass introduced into cylinder in Kg over 720 CA cycle
megr_thEGR mass from throttle into intake manifold over 720 CA cycle in Kg
megr_measMeasured EGR mass from EGR system into intake manifold in Kg over 720 degree CA cycle
(A/F) ═ fresh air to fuel mass ratio of the engine (which can be controlled to a constant desired value, e.g., near 14.7, based on feedback from one or more exhaust gas sensors (e.g., UEGO or HEGO feedback))
PmanIntake manifold air pressure in PA
TmanIntake manifold air temperature in degrees kelvin
VdAs engine displacement (cubic meter)
R is gas constant (287.058, in J/(Kg deg K))
Thus, when operating in PttB mode with the vehicle stationary, and with PttB AC current load substantially constant or slowly varying, closed loop fuel system control based on UEGO/HEGO may be used to determine the average injected fuel mass, and the engine speed feedback control system may increase or decrease the commanded engine torque to maintain the commanded engine speed. Further, when in the stationary PttB mode, a Variable Cam Timing (VCT) system for the engine (where equipped) may map the cam to a position that provides the best combination of minimum fuel consumption and combustion stability.
For a gasoline engine operating at a fixed air-fuel ratio (e.g., stoichiometric), and for a given or fixed cam timing, the engine output torque may vary according to the fresh air mass flow rate and spark timing. For engines having an EGR system (e.g., 249), as measured EGR increases, spark timing may be advanced to compensate for the increase in cylinder combustion burn duration due to the increase in measured EGR, as is generally understood in the art.
Thus, in situations where the vehicle is inferred to be operating under conditions of reduced air exchange as discussed with respect to method 400, the EGR fraction in the air proximate the vehicle may increase over time. Once the EGR value reaches a particular value (e.g., 30%), the fuel may not burn completely, which may result in a reduction in engine combustion torque. While spark advance may be used as mentioned above to maintain the combustion pressure peak near a desired value (e.g., 10 CA degrees after top dead center or TDC), as the EGR fraction continues to increase, even advancing the spark may not be sufficient to prevent combustion torque from decreasing, and combustion stability may therefore deteriorate, at which time controlled engine shut-down may be desired in order to avoid engine compromise.
Thus, when operating in PttB mode with reduced air exchange, it may be desirable to measure or estimate the unmetered EGR entering the intake manifold through the intake passage (e.g., 242) and intake air filter (e.g., 286), compensate for the increased EGR mass flow due to the unmetered EGR, and implement a controlled engine shut-off if continued engine operation is not desired.
Thus, proceeding to 450, method 400 may include: the otherwise unmetered or unmeasured EGR is measured or estimated. This may be done using one or more methods. Thus, proceeding to FIG. 5, a first exemplary method for measuring/estimating unmetered EGR is depicted. The method 500 may continue with fig. 4, and thus may be implemented by a controller (such as the controller 212 depicted at fig. 2) and may be stored as executable instructions in a non-transitory memory at the controller. The instructions for implementing the method 500 and the remaining methods included herein may be executed by the controller based on instructions stored on a memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to fig. 1-2. The controller may employ the actuators to alter the state of the devices in the physical world as discussed above with respect to fig. 4.
At 505, method 500 may include: as the unmetered EGR fraction increases, the total air charge (m) is calculated from measured intake manifold air pressure and temperaturetac) (refer to equation 3).
Proceeding to 510, the method 500 may include: according to injected fuel mass (m)f) And air-to-fuel ratio to calculate a fresh air charge (m)fac) (see equation 2) where one or more exhaust gas sensors (e.g., UEGO and/or HEGO) are relied upon to maintain a desired air/fuel ratio.
Proceeding to 515, method 500 may include: obtaining EGR mass flow (m) from an EGR systemegr_meas) The measurement result of (1). Such measurements may be obtained, for example, via at least one or more of a pressure sensor (e.g., 292) positioned in the EGR system, a duty cycle of the EGR valve (e.g., 253).
Continuing to the step of (d) at 520,the method 500 may include: according to mtac(obtained at step 505) with mfac(obtained at step 510) to calculate a total EGR mass air flow (m) into the engine cylindersegr) (refer to equation 4).
Proceeding to 525, the method 500 may include: according to megr(obtained at step 520) with megr_measThe difference between (obtained at 515) is used to calculate the EGR mass flow from the throttle (e.g., 262) into the intake manifold (see equation 6).
Continuing to 530, the method 500 may include: calculating EGR fraction (m)egr/mtac) And/or EGR percentage (100 x (EGR fraction)).
Method 500 may then return to step 450 of method 400. However, it is understood that the method 500 may continue to run to update the values as the method 400 proceeds. Therefore, dashed line 535 depicts a continuous operation or cycle of method 500, wherein such cycle continuously updates the EGR fraction and communicates the result to method 400.
As mentioned above, method 500 depicts one exemplary method for calculating an EGR fraction. Turning now to FIG. 6, a second exemplary method for measuring/estimating unmetered EGR is depicted. The method 600 may continue to step 450 of fig. 4, and thus may be implemented by a controller (such as the controller 212 depicted at fig. 2), and may be stored as executable instructions in a non-transitory memory at the controller. The instructions for implementing the method 600 and the remaining methods included herein may be executed by the controller based on instructions stored on a memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to fig. 1-2. The controller may employ the actuators to alter the state of the devices in the physical world as discussed above with respect to fig. 4. In particular, method 600 may be used where the engine is equipped with a MAF sensor (e.g., 238) to measure the total air mass (fresh air and EGR) entering the intake manifold from the throttle (e.g., 262).
The method 600 begins at 605 and may include: obtaining a total mass of air (m) entering an intake manifold from a throttletac_th) Measurement result (reference side) ofRun 5). Proceeding to 610, method 600 may include: according to injected fuel mass (m)f) And air-to-fuel ratio to calculate a fresh air charge (m)fac) As discussed above with respect to step 510 of method 500.
Continuing to 615, method 600 may include: obtaining a measurement of EGR mass flow (m) from an EGR systemegr_meas) As discussed above with respect to step 515 of method 500. Proceeding to 620, method 600 may include: according to mtac_th-mfac+megr_measTo calculate total EGR mass flow (m) into the engine cylinderegr) (refer to equations 5 and 6) where mtac_thObtained at step 605, mfacObtained at step 610, and megr_measObtained at step 615.
Proceeding to 625, method 600 may include: according to mfac(obtained at step 610) with megr(obtained at step 620) to calculate a total air charge (m) inducted into the engine cylindertac) (refer to equation 4). Then, continuing to 630, method 600 may include: calculating EGR fraction (m)egr/mtac) And/or EGR percentage (100 x (EGR fraction)).
Method 600 may then return to step 450 of method 400. However, it is understood that method 600 may continue to run to update the values as method 400 proceeds. Therefore, the dashed line 635 depicts a continuous operation or cycle of the method 600, wherein such cycle continuously updates the EGR fraction and communicates the result to the method 400.
Turning now to FIG. 7, a third
The
Accordingly,
Proceeding to 710,
Proceeding to 715,
M is obtained at 715egrWhere
Returning to step 450 of method 400, with an EGR fraction determined by one of
Proceeding to 460, method 400 may include: indicating whether the EGR fraction (calculated above with respect to step 450) exceeds a first threshold EGR fraction. The first threshold EGR fraction may include a non-zero EGR fraction (e.g., greater than 0.2, greater than 0.3, greater than 0.4) that is near (within a predetermined amount of) an EGR fraction at which the compensation method for maintaining the desired engine torque will be ineffective. If the first threshold EGR fraction has not been indicated to have been reached at 460, method 400 may return to 450, at 450, and may continue to determine and compensate for the EGR fraction (step 455). Alternatively, in response to indicating that the EGR fraction has reached the first threshold EGR fraction, method 400 may proceed to 465. At 465, the method 400 may include: the vehicle operator is alerted that a controlled engine shut-off event is imminent in the absence of a mitigating action.
Such an alert may be similar in nature to the alert discussed above with respect to step 420, but may be slightly different in some examples in order to convey different information, particularly with respect to step 465, that the engine will be shut down due to potential engine instability, which may further affect the powering of the electrical load via the use of PttB mode. Thus, at 465, the alert may include a message communicated to the vehicle operator that engine stability has become an issue due to a reduced air exchange condition. Such a message may include an indication that the engine will be shut down if no mitigating action is taken to reduce the EGR fraction introduced to the engine. For example, the message may include instructions for increasing the exchange of air in the vicinity of the vehicle. This may result in a reduction in the fraction of EGR introduced into the engine, which may allow for avoiding or at least postponing engine shut-down if such action is possible. As discussed above, such messages may be communicated to the vehicle operator in the form of text-based messages via the vehicle dashboard (e.g., 196) or a separate screen associated with the vehicle dashboard (e.g., a Ford Sync screen). In another example, such messages may include audible messages that are under the control of the controller and communicated via one or more speakers associated with the vehicle dashboard. In such an example, the controller may string together several keywords or phrases stored as a table at the controller to produce an audible message. Such audible messages may be provided via the dashboard in addition to or instead of text-based messages. In another example, such messages may additionally or alternatively include text messages sent to software applications used by the vehicle operator (e.g., a smart phone application, a tablet computer application, etc.), and/or text messages sent to the vehicle operator's phone (e.g., a smart phone). In still other examples, such messages may additionally or alternatively include a controller of the vehicle commanding a particular sequence of horn rings (e.g., five rings in rapid succession, etc.) and/or a particular sequence of exterior and/or interior light flashes.
Although not explicitly shown, in some examples, when it is determined that the EGR fraction is above the first threshold EGR fraction, the controller may command the above-mentioned second priority outlet to be turned off while maintaining power to the first priority outlet. In such an example, the alert at 465 may be referred to as a first EGR fraction alert, and may include information regarding the fact that the second priority outlet is turned off. In some examples, the alert may include a time range (e.g., 1 minute or less, 30 seconds or less, 15 seconds or less, etc.) during which the second priority outlet will be turned off in response to the EGR fraction being higher than the first priority EGR fraction such that the vehicle operator has a predetermined amount of time to disconnect the component from the second priority outlet before turning off the second priority outlet via the controller.
After communicating the message to the vehicle operator at 465, method 400 may proceed to 470. At 470, the method 400 may include: the EGR fraction inducted into the engine continues to be monitored and compensated for, as discussed above with respect to steps 450 and 455 of method 400. Continuing to 475, method 400 may include: indicating whether the EGR fraction has reached a second threshold EGR fraction. It is appreciated that the second threshold EGR fraction may include an EGR fraction that is a predetermined amount (see description above regarding step 460) above the first threshold EGR fraction. In other words, it may be appreciated that the second threshold EGR fraction may include an EGR level introduced to the engine for which compensation mechanisms such as advancing spark and/or reducing EGR flow (e.g., to no flow) are no longer sufficient to maintain the desired engine torque.
If at 475 it is indicated that the second threshold EGR fraction has not been reached, method 400 may return to 460 where, again, an evaluation may be made as to whether the EGR fraction is still above the first threshold EGR fraction. In other words, where mitigating action has been taken to increase the air exchange near the vehicle, then the EGR fraction inducted into the engine may be reduced below the first threshold EGR fraction. Alternatively, if the EGR fraction continues to be above the first threshold EGR fraction, the EGR fraction may continue to be monitored and compensated for until an indication is made that the EGR fraction has reached the second threshold EGR fraction. In some examples, more than one alert may be provided in a sequential manner when the EGR fraction approaches the second threshold EGR fraction. For example, a first alert may be communicated to a vehicle operator when it is indicated that the EGR fraction has exceeded a first threshold EGR fraction, then a second alert may be communicated a predetermined time after the first alert (or when the EGR fraction increases a predetermined amount above the first threshold EGR fraction), then a third alert may be communicated another predetermined time after the second alert (or when the EGR fraction increases another predetermined amount above the first threshold EGR fraction), and so on.
In response to the EGR fraction reaching or exceeding the second threshold EGR fraction, method 400 may proceed to 480. At 480, method 400 may include: the engine is turned off. Specifically, fuel injection to the engine cylinder may be stopped under control of a vehicle controller, and spark provided to the engine cylinder may be interrupted under control of the vehicle controller. The method 400 may then end.
Although not explicitly shown, in some examples, when it is determined that the EGR fraction is above the second threshold EGR fraction, the controller may command the first priority outlet mentioned above to be turned off before turning off the engine. In such an example, an alert substantially similar to the alert at 465, but referred to herein as a second EGR fraction alert, may include information relating to the fact that the first priority outlet is turned off. In some examples, the alert may include a range of time or predetermined duration (e.g., 1 minute or less, 30 seconds or less, 15 seconds or less, etc.) during which the first priority outlet will be shut off in response to the EGR fraction being above the second threshold EGR fraction such that the vehicle operator may have a predetermined amount of time to disconnect the component from the first priority outlet before the engine is shut off.
Turning now to FIG. 8, an
At time t0, the engine is on, combusting air and fuel (curve 805). The vehicle is being propelled by the engine because the vehicle speed is a positive non-zero speed (curve 810). PttB mode is not requested (curve 815) and by time t0, the vehicle is not operating with reduced air exchange (curve 820). In other words, it can be appreciated that at time t0, the vehicle is traveling along a road having sufficient air exchange such that exhaust gas from the engine to atmosphere is substantially not reintroduced to the engine via the intake passage (e.g., 242). Since PttB mode has not been requested and the vehicle is not operating with reduced air exchange, no vehicle operator input is requested (curve 825), and thus no operator input has been received (curve 830). There is a level of EGR directed to the intake manifold (curve 835), but it is understood that at time t0, EGR directed to the intake manifold includes EGR actively directed to the intake manifold under control of the vehicle controller by the EGR system (e.g., 249), specifically via controlling the duty cycle of the EGR valve (curve 845). At time t0, no engine off warning is provided (curve 840), and spark timing is neither substantially advanced nor substantially retarded (curve 850).
Between times t0 and t1, the vehicle decelerates, and at time t1, a reduced air exchange condition is indicated. As discussed above, such a condition may be indicated based on a loss of GPS satellite signals as monitored via an in-vehicle navigation system. As one example, where an on-board navigation system communicates with 12 GPS satellites and the number drops by 3, 4, 5, 6, 7, etc., it may be inferred that the vehicle has entered an environment with reduced air exchange. In some examples, such a condition may additionally or alternatively be indicated via one or more onboard cameras (e.g., 195) configured to monitor a space surrounding the vehicle and communicate with the vehicle controller when a reduced air exchange condition is evident from images and/or video recorded via the onboard cameras. In some examples where the vehicle includes one or more of laser, radar, sonar, and/or acoustic sensors (e.g., 133), additionally or alternatively, such conditions of reduced air exchange may be indicated based on output from one or more of such sensors. In still other examples, the indication of such a reduced air exchange condition may be indicated based on learned information stored at the controller, as discussed in detail above with respect to fig. 3. Specifically, there may be situations where the vehicle typically travels to a location where air exchange is reduced (e.g., a parking lot, a construction site, etc.), and such information may be learned by the controller over time so that when the vehicle is in such a location, a condition of reduced air exchange may be indicated.
At time t2, the vehicle comes to a stop (curve 810) and the vehicle operator requests PttB mode for supplying power to one or more electrical loads external to the vehicle. Thus, in this exemplary timeline, it will be appreciated that the reduced air exchange condition includes a construction site where a vehicle has driven into the site with a reduced air exchange between the exhaust and atmosphere such that exhaust vented to atmosphere may be reintroduced to the engine via the intake passage over time. When PttB mode is requested, the engine is maintained on (curve 805).
With the engine in operation, and further in response to having requested PttB mode, and further in response to an indication that the vehicle is in a reduced air exchange environment, the vehicle controller initiates an alert requesting an operator input to continue PttB mode under control of the engine. In this exemplary timeline, although not explicitly shown, it is understood that the alerts include audible alerts requesting vehicle operator input, and additionally include text-based alerts displayed on a screen associated with a vehicle dashboard.
In response to the request for operator input at time t2, operator input is received by the controller at time t 3. In particular, in this exemplary timeline, it can be appreciated that the vehicle operator has entered into the screen, on the dashboard, the desire to maintain the engine in operation for powering external electrical loads, even though the vehicle has been understood to be in a reduced air exchange environment via the alert provided to the vehicle operator.
Thus, between times t3 and t4, engine operation continues for powering the desired external electrical load. Further, while not explicitly shown at
Between times t4 and t5, a significant increase in EGR fraction is indicated, as monitored via one or more of the methods of FIGS. 5-7. To compensate for this increase, engine control strategies alter the duty cycle of the EGR valve and advance spark timing in order to maintain desired engine torque for engine stability and for supplying uninterrupted power to external electrical loads. Between times t5 and t6, an even further increase in EGR fraction is indicated, and additional compensatory action is taken that involves adjusting the EGR valve to close for a greater amount of time and further advancing the spark timing. Similarly, between times t6 and t7, the EGR fraction continues to increase and the spark timing is further advanced, and the EGR valve is commanded closed to contain any exhaust gas directed to the intake manifold via the EGR system.
At time t7, a first threshold EGR fraction is reached. Thus, a warning is provided to the vehicle operator indicating that an engine shut-down is imminent if no mitigating action is taken. In this exemplary timeline, it will be appreciated that the alerts include audible messages in the form of a particular sequence of horn rings that can be readily heard by any device powered by the vehicle outside the vehicle. In addition, the alert includes a text message sent to the vehicle operator's phone and further includes a text-based message displayed on the vehicle dashboard.
However, between times t7 and t8, the EGR fraction continues to be monitored and indicates that the EGR fraction continues to increase. At time t8, a second alert is issued, the second alert comprising the same alert as the first alert issued at time t7, indicating that an engine shut down is imminent if no mitigating action is taken. Between times t8 and t9, the EGR fraction continues to increase, and at time t 9. A third alert is issued indicating an impending engine shutdown. At time t10, the second threshold EGR fraction is indicated to be reached, and therefore, the engine is controlled to be off (curve 805). It is understood that engine shut-off includes: the vehicle controller commands a stop of fuel injection to the engine cylinder, and further comprises: a spark plug coupled to a cylinder of the engine is commanded to cease providing spark. With the engine off at time t10, the EGR fraction inducted into the engine cylinders drops rapidly. Further, PttB mode is no longer requested because conditions have become such that PttB mode is no longer an option for a vehicle in a particular location. In other words, initiation of the PttB mode may be prevented via the vehicle controller even if the vehicle operator attempts to reinitiate the PttB mode. Between times t10 and t11, the engine is maintained off.
While the above description relates to controlling engine operation with reduced air exchange, other factors may additionally or alternatively facilitate providing consistent and/or maximum power to an external load. One such example includes engine temperature. Specifically, when supplying power to an external load, as engine temperature increases, heat transfer from the engine to the generator (e.g.,
Thus, turning now to FIG. 9, an exemplary method 900 for reducing engine temperature when operating in PttB mode is depicted. Specifically, the method 900 includes: the method includes monitoring engine temperature while the engine is operating in the PttB mode, and upon determining that the engine temperature has exceeded a first engine temperature threshold, alerting a vehicle operator to take mitigating action in the form of opening a hood of the vehicle to reduce the engine temperature. In this way, the use of the cooling fan when the engine is used to supply power to the external load may be reduced, which may improve fuel economy and increase the maximum power provided to the external load.
The method 900 will be described with reference to the systems described herein and shown in fig. 1-2, but it should be understood that similar methods may be applied to other systems without departing from the scope of the present disclosure. The method 900 may be implemented by a controller (such as the controller 212 in fig. 2) and may be stored as executable instructions in a non-transitory memory at the controller. The instructions for implementing the method 900 and the remaining methods included herein may be executed by the controller based on instructions stored on a memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to fig. 1-2. The controller may employ actuators such as one or more spark plugs (e.g., 298), one or more fuel injectors (e.g., 266), a hood actuator (e.g., 185), etc. to alter the state of the device in the physical world according to the methods depicted below.
Method 900 begins at 905 and may include: vehicle operating conditions are estimated and/or measured. The operating conditions may be estimated, measured, and/or inferred, and may include: one or more vehicle conditions, such as vehicle speed, vehicle location, etc.; various engine conditions such as engine state, engine load, engine speed, air-fuel ratio, manifold air pressure, etc.; various fuel system conditions such as fuel level, fuel type, fuel temperature, etc.; various evaporative emissions system conditions, such as fuel vapor canister loading, fuel tank pressure, etc.; and various environmental conditions such as ambient temperature, humidity, atmospheric pressure, and the like.
Proceeding to 910, method 900 includes: indicating whether the vehicle operator has requested that the PttB mode be used. As discussed above, in some examples, the vehicle operator may select PttB mode via an instrument panel (e.g., 196), and may further select an engine speed at which the engine is operable for operation in PttB mode. If PttB mode is not requested at 910, method 900 may proceed to 915. At 915, method 900 may include: and maintaining the current vehicle working condition. For example, if the engine is operating to propel the vehicle without supplying power to an external load, such engine operation may be maintained. Such vehicle operating parameters may be maintained if the engine is not in operation, such as if electric power is being used to propel the vehicle. Other vehicle operating parameters that do not include powering an external load are also within the scope of the present disclosure. Method 900 may then end.
Returning to 910, method 900 may proceed to 920. At 920, method 900 may include: the engine is controlled in a speed feedback mode, wherein engine speed is maintained substantially constant, and the load on the engine is determined based on the total torque load on the engine from one or more sources, including but not limited to external loads, as discussed in detail above with respect to step 445 of method 400.
Method 900 may proceed to 925 in the case where the engine is controlled in PttB mode. At 925, method 900 may include: the engine temperature is monitored. The engine temperature may be monitored, for example, via an engine coolant temperature sensor (e.g., 186). Proceeding to 930, method 900 includes: indicating whether the engine temperature has exceeded a first engine temperature threshold. In one example, the first engine temperature threshold may comprise 50 ° f, but it is understood that the first engine temperature threshold may comprise any temperature in the range of 40 ° f to 60 ° f without departing from the scope of the present disclosure. If it is indicated at 930 that the engine temperature has not exceeded the first engine temperature threshold, method 900 may return to 925 where method 900 continues to monitor the engine temperature while operating in PttB mode at 925.
Alternatively, in response to indicating at 930 that the engine temperature exceeds the first engine temperature threshold, method 900 may proceed to 935. At 935, method 900 may include: a first engine temperature alert is issued to a vehicle operator requesting that the vehicle operator take mitigating action to reduce the engine temperature. Specifically, the first engine temperature alert may include a request to open a hood of the vehicle in order to cool the engine.
The first engine temperature alert may be communicated to the vehicle operator via a vehicle dashboard (e.g., 196) or a separate screen associated with the vehicle dashboard (e.g., a Ford Sync screen) in the form of a text-based message. In another example, such an alert may comprise an audible message under control of the controller and communicated via one or more speakers associated with the vehicle dashboard. For example, the controller may string together several keywords or phrases stored at the controller to generate an audible message requesting the vehicle operator to open the hood of the vehicle. In some examples, an audible message may be provided via the dashboard in addition to or instead of the text-based message. Additionally or alternatively, the first engine temperature alert may be wirelessly communicated to the vehicle operator via, for example, a text message sent to a software application (e.g., a smartphone application, a tablet computer application, etc.) used by the vehicle operator and/or a text message sent to a phone of the vehicle operator (e.g., a smartphone). In still other examples, such messages may additionally or alternatively include a controller of the vehicle commanding a particular sequence of horn rings and/or a particular sequence of exterior and/or interior light flashes.
Continuing, in response to sending the first engine temperature alert to the vehicle operator, at 940, method 900 may include: indicating whether the vehicle operator has taken the requested mitigation action. It is to be appreciated that in some examples, if no mitigating action to open the hood has been indicated for a predetermined duration (e.g., 3 minutes or less, 2 minutes or less, 1 minute or less, etc.), then the method 900 may indicate that a mitigating action has not been taken, at which point the method 900 may proceed to 960, as will be discussed in further detail below.
Alternatively, method 900 may proceed to 945 in response to an indication at the controller that the hood has been opened. It will be appreciated that in some examples, the act of opening the hood may signal to the controller that the hood has been actuated open. Additionally or alternatively, in response to opening the hood, the vehicle operator may input into the vehicle dashboard the fact that the vehicle hood has been opened (e.g., via a touch screen, such as a Ford Sync screen or via the software application mentioned above), which may then be communicated to the controller. It will be appreciated that opening of the hood may allow for increased air circulation in the vicinity of the engine compartment, which may be used to cool the engine, or at least slow the rate of rise of engine temperature. Cooling the engine and/or slowing the rate at which the engine temperature increases may allow for more efficient power to be supplied to the external load.
At 945, method 900 may continue to monitor engine temperature with the hood open. As discussed above, such monitoring may be via an engine coolant temperature sensor (e.g., 186). Further, monitoring engine temperature may include: the temperature of the engine cylinder temperature is monitored via one or more cylinder temperature sensors (e.g., 257). Proceeding to 950, method 900 may include: a cooling fan (e.g., 295) is controlled based on the monitored engine temperature. As one example, the cooling fan may be controlled to turn off with the hood open, however as the engine temperature continues to increase in the direction of the second engine temperature threshold (see step 955), the cooling fan may be activated and controlled in a manner that maintains the engine temperature below the second threshold, if possible.
Returning to 940 for comparison, in response to the hood opening mitigating action not being taken, method 900 may proceed to 960, at 960, where the cooling fan is activated. Thus, it can be appreciated that when a hood opening mitigating action is taken as discussed above, the activation of the cooling fan can be avoided or at least postponed, which can be used to improve fuel economy. However, where no mitigating action is taken, then the cooling fan may be enabled in turn at 960. Proceeding to 965, the method 900 may include: engine temperature is monitored in a manner similar to that described at 945, and at 970, method 900 may include: the cooling fan is controlled based on the monitored engine temperature, similar to that described at 950. However, it will be appreciated that the difference between controlling the cooling fan at 950 where the hood is open and controlling the cooling fan at 970 where the hood remains closed is that: the aggressiveness (e.g., fan speed) at which the fan is controlled at 950 may be reduced compared to step 970. In other words, when the hood remains closed, the engine temperature may increase at a faster rate than when the hood is open. Thus, the fan speed may be increased at a faster rate at step 970 than at step 950. In this way, a lower energy usage for cooling the engine may be achieved at step 950 where the hood is opened as compared to step 970 where the hood is closed.
Regardless of whether the hood is open or closed, method 900 may proceed to 955, at 955, an assessment may be made as to whether the engine temperature has exceeded a second engine temperature threshold. It is appreciated that the second engine temperature threshold may be greater than the first engine temperature threshold. It will be further appreciated that the second engine temperature threshold may include an engine temperature where it may be desirable to shut off the second priority outlet (e.g., one or more compressors, saws, drills, etc.) in order to maintain power to the first priority outlet (e.g., a computer and/or a device with sensitive electronics). As one example, the second priority outlet may provide a 240V power supply, while the first priority outlet may provide a 120V power supply. However, such examples are illustrative, and in other examples, such distinction may not be used to distinguish between a first priority egress and a second priority egress without departing from the scope of the present disclosure.
As discussed above with respect to fig. 2, the one or more cylinder temperature sensors (e.g., 257) may be communicatively coupled to a circuit breaker of an outlet of a power supply box (e.g., 191) such that the second priority outlet may be automatically shut off when it is determined via the one or more cylinder temperature sensors that the engine temperature has exceeded the second engine temperature threshold. Thus, at 955, if a second engine temperature threshold has not been indicated to have been reached, the method 900 may continue to monitor the engine temperature and control the cooling fan in a manner dependent upon whether the hood is open.
Alternatively, in response to the engine temperature exceeding the second threshold, method 900 may proceed to 980, at 980, a second engine temperature alert may be issued to the vehicle operator informing the vehicle operator that the second priority outlet is turned off. The second engine temperature alert may be substantially similar to the first engine temperature alert discussed in detail above at 935, except that the second engine temperature alert may include information regarding the fact that the second priority outlet is turned off.
While method 900 depicts the second engine temperature alert as being simultaneous with turning off the second priority outlet, it may be appreciated that in other examples, the second engine temperature alert may be issued in response to the engine temperature as monitored via the one or more cylinder temperature sensors and/or the engine coolant temperature sensor indicating that the engine temperature is within a threshold number of degrees of the second engine temperature threshold (e.g., within 5 degrees or less, within 3 degrees or less, etc.), such that a vehicle operator may take mitigating action to disconnect the externally powered component from the second priority outlet prior to turning off the outlet. In some examples, such an alert may include information based on the rate of temperature increase in order to inform the vehicle operator of an estimated time frame during which the second priority outlet may be turned off. For example, based on the rate of temperature increase, the controller may determine that the second priority outlet may be turned off within 5 minutes, 4 minutes, 3 minutes, etc. Such information may be conveyed in the alert so that the vehicle operator knows the time range during which to shut down and/or prepare to shut down the second priority outlet.
In response to turning off the second priority egress at 980, method 900 may proceed to 985. At 985, method 900 may include: the cooling fan continues to be controlled based on the monitored engine temperature. For example, similar to that discussed above, the cooling fan may be controlled at a greater rotational speed without opening the hood by the vehicle operator than with the hood open. In other words, after the second engine temperature threshold is exceeded, the rate at which engine temperature increases with the hood remaining closed may be faster than if the hood were open. Thus, more aggressive control (e.g., faster rotational speeds) of the cooling fan may be employed with the hood closed than with the hood open.
Proceeding to 990, method 900 may include: indicating whether the engine temperature has exceeded a third engine temperature threshold. It will be appreciated that the third engine temperature threshold may include temperatures greater than the second engine temperature threshold, and may include temperatures where it may be desirable to shut down the engine to avoid undesirable issues associated with powering the first priority outlet. Such undesirable issues may relate to engine hesitation, engine stall, engine degradation, and the like. Such undesirable issues related to engine operation may in turn adversely affect the external load supplied by the first priority outlet, and thus, it may be desirable to shut off power to the first priority outlet when the engine temperature exceeds the third engine temperature threshold at 990. As discussed above, it may be appreciated that one or more cylinder temperature sensors (e.g., 257) may be communicatively coupled to a circuit breaker of an outlet of a power supply box (e.g., 191) such that the first priority outlet may be automatically shut off when it is determined via the one or more cylinder temperature sensors that the engine temperature has exceeded the third engine temperature threshold.
Accordingly, at 990, in response to an indication that the third engine temperature threshold has not been reached, method 900 may continue to control the cooling fan as a function of the monitored engine temperature. Alternatively, in response to the engine temperature exceeding the third engine temperature threshold, method 900 may proceed to 995, where the vehicle operator may be issued a third engine temperature threshold alert informing the vehicle operator that the first priority outlet is turned off at 995. The third engine temperature alert may be substantially similar to the first engine temperature alert discussed in detail above at 935 (and the second engine temperature alert discussed in detail at 980), except that the third engine temperature alert may include information regarding the fact that the first priority outlet is turned off.
While method 900 depicts the third engine temperature alert as being concurrent with turning off the first priority outlet, it may be appreciated that in other examples, the third engine temperature alert may be issued in response to the engine temperature as monitored via the one or more cylinder temperature sensors and/or the engine coolant temperature sensor indicating that the engine temperature is within a threshold number of degrees of the third engine temperature threshold (e.g., within 5 degrees or less, within 3 degrees or less, etc.), such that a vehicle operator may take mitigating action to disconnect the externally powered component from the first priority outlet prior to turning off the outlet. In some examples, such an alert may include information based on the rate of temperature increase in order to inform the vehicle operator of an estimated time frame during which the first priority outlet may be turned off. For example, based on the rate of temperature increase, the controller may determine that the first priority outlet may be turned off within 5 minutes, 4 minutes, 3 minutes, etc. Such information may be conveyed in the alert so that the vehicle operator knows the time range during which to shut down and/or prepare to shut down the first priority outlet.
Where the first priority egress is turned off at 995, method 900 may proceed to 997. At 997, the method 900 may include: the vehicle operating parameters are updated. Specifically, updating the vehicle operating parameters may include saving information at the controller regarding: the rate at which the first, second, and third engine temperature thresholds are reached, whether the hood is open in response to reaching the first engine temperature threshold, and the like. Proceeding to 998, method 900 may include: engine shut-down is implemented by discontinuing the supply of fuel (and spark, where spark is provided) to the engine. Method 900 may then end.
The approach of method 900 discussed above does not take into account the possibility of introducing unmetered EGR to the engine when the engine is operated to power one or more external loads via operation in PttB mode. The method 900 is so discussed because it is recognized herein that there may be situations where the vehicle is operating without a reduction in air exchange (e.g., open air operation) as compared to situations where air exchange is reduced as discussed above. However, it is also recognized herein that there may be situations where PttB mode is requested under conditions of reduced air exchange and it may also be desirable to issue a warning requesting a mitigating action to reduce engine temperature when operating the engine in PttB mode.
Thus, turning now to fig. 10, a high level exemplary method 1000 is depicted illustrating an exemplary method for determining whether PttB mode is requested with reduced air exchange, and if not, then PttB mode may be controlled as discussed above with respect to fig. 9. Alternatively, in the case where the PttB mode is requested under the condition of reduced air exchange, then the PttB mode may be controlled based on the methods of fig. 4 and 9.
Method 1000 begins at 1005 and includes: vehicle operating conditions are estimated and/or measured. The operating conditions may be estimated, measured, and/or inferred, and may include: one or more vehicle conditions, such as vehicle speed, vehicle location, etc.; various engine conditions such as engine state, engine load, engine speed, air-fuel ratio, manifold air pressure, etc.; various fuel system conditions such as fuel level, fuel type, fuel temperature, etc.; various evaporative emissions system conditions, such as fuel vapor canister loading, fuel tank pressure, etc.; and various environmental conditions such as ambient temperature, humidity, atmospheric pressure, and the like.
Proceeding to 1010, method 1000 includes: indicating whether PttB mode is requested. As discussed above, in some examples, the vehicle operator may select PttB mode via an instrument panel (e.g., 196), and may further select an engine speed at which the engine is operable for operation in PttB mode. If PttB mode is not requested at 1010, method 1000 may proceed to 1015. At 1015, method 1000 may include: and maintaining the current vehicle working condition. For example, if the engine is operating to propel the vehicle without supplying power to an external load, such engine operation may be maintained. Such vehicle operating parameters may be maintained if the engine is not in operation, such as if electric power is being used to propel the vehicle. Other vehicle operating parameters that do not include powering an external load are also within the scope of the present disclosure. The method 1000 may then end.
Returning to 1010, in response to receiving a PttB mode request at the controller, the method 1000 may proceed to 1020. At 1020, method 1000 may include: indicating whether PttB mode is requested with reduced air exchange. Specifically, as discussed above, a reduced air exchange condition may be indicated when the vehicle has traveled to a location where there was an indicated reduction in GPS satellite signals while the vehicle was stopped or after the vehicle has stopped. For example, if 12 GPS satellite signals are indicated via the on-board navigation system, and then the number is reduced by a threshold number when the vehicle comes to a stop or after the vehicle has stopped, a reduced air exchange condition may be indicated. Additionally or alternatively, a reduced air exchange condition may be indicated via the controller based on the learned travel routine as discussed with respect to fig. 3. For example, based on prior information received at the controller regarding the location of the vehicle, the controller (in some examples, in conjunction with an in-vehicle navigation system) may indicate that the vehicle is in a reduced air exchange condition with a high probability.
If a reduced air exchange condition is not indicated at 1020, method 1000 may continue to control the PttB engine operating mode as discussed above with respect to FIG. 9 and may not include taking the step of monitoring for unmetered EGR since it has been determined that the vehicle is not operating in a reduced air exchange condition. Accordingly, at 1025, method 1000 may continue to implement method 900 as described in fig. 9, and method 1000 may end.
Alternatively, method 1000 may proceed to 1030 in response to a controller determining that a vehicle operator has requested a PttB engine operating mode, and in the event that a further determination is made that PttB mode is requested with reduced air exchange. At 1030, method 1000 may include: compensating for unmetered EGR and taking mitigating action as discussed with respect to method 400 depicted at fig. 4, and may further include: the engine temperature is monitored and mitigation actions are taken as discussed with respect to method 900 depicted at fig. 9. In other words, the two methods of fig. 4 and 9 may run simultaneously, and the two methods may communicate with each other.
Specifically, an example of how the methods of fig. 4 and 9 may be used in a situation where PttB mode is requested and a condition indicating a reduction in air exchange will now be discussed. In one example, in response to a PttB mode request with reduced air exchange, engine temperature may be monitored via the method of FIG. 9 and the unmetered EGR may be monitored in accordance with the method of FIG. 4. Where the engine temperature reaches the first engine temperature threshold (see 930 of method 900) before the unmetered EGR reaches the first threshold EGR fraction (see 460 of method 400), the unmetered EGR may be monitored and compensated for as discussed with respect to steps 450 and 455 of method 400. In response to the engine temperature reaching the first engine temperature threshold, a first engine temperature alert may be issued as discussed with respect to step 935 of method 900, and the engine cooling fan may be controlled depending on whether a hood opening mitigating action has been taken. Then, assuming the unmetered EGR reaches the first threshold EGR fraction before the engine temperature reaches the second engine temperature threshold (see step 955 of method 900), an alert may be communicated to the vehicle operator informing the operator that an engine shut-down is imminent unless mitigating action is taken to increase air circulation (see step 465). In some examples, such an alert may include an indication that the second priority outlet is turned off, or may include an indication that the second priority outlet is to be turned off within a particular time frame (e.g., 1 minute or less, 30 seconds or less, 15 seconds or less, etc.). However, in other examples, such an alert may be communicated without otherwise including the turning off of the second priority egress or providing information that the second priority egress is to be turned off within a particular time frame.
In the event that the first threshold EGR fraction is reached and the second priority outlet is turned off, then if the engine temperature subsequently reaches the second engine temperature threshold (see step 955 of method 900), a second engine temperature alert may be issued to notify the vehicle operator that the second engine temperature threshold was reached, but because the second priority outlet has been turned off, then the alert may not include information related to turning off the second priority outlet. In other examples where the first threshold EGR fraction is reached and the second priority outlet is not turned off, but instead the alert associated with reaching the first threshold EGR fraction includes only information related to the impending turn off if no mitigating action is taken, then when the second engine temperature alert is issued, the second engine temperature alert may include information related to the fact that: the second priority outlet is or will be shut off due to the second engine temperature threshold being reached.
Next, if the EGR fraction exceeds the second threshold EGR fraction before the engine temperature exceeds the third engine temperature threshold, the fact that the second threshold EGR fraction has been reached may cause the engine to be shut down, which may additionally include an alert indicating that the first priority outlet is to be shut down for a predetermined amount of time. In other words, although the engine temperature has remained below the third engine temperature threshold, because it has been determined that the unmetered EGR exceeds the second threshold EGR fraction, action may be taken to shut off the first priority outlet and implement an engine shut-off. Alternatively, if a third engine temperature threshold is reached before it is determined that the unmetered EGR exceeds the second threshold EGR fraction, a third alert may be issued (referring to step 995 of method 900) relating to the engine temperature reaching the third engine temperature threshold, and the engine may then be turned off, which may include turning off the first priority outlet or providing information relating to when the first priority outlet is to be turned off.
The above examples are intended to include illustrative examples of how the methods of fig. 4 and 9 may be used in conjunction with one another in situations where PttB mode is requested with reduced air exchange. Such examples are not intended to be limiting. For example, in other situations, the engine temperature may reach the second engine temperature threshold before the first threshold EGR fraction is exceeded. In such an example, the second priority outlet may be turned off as a result of the second engine temperature threshold being reached. Then, if the first threshold EGR fraction is subsequently exceeded, then the alert (see step 465) may include information relating to an impending engine shutdown, but may not include information relating to the second priority outlets because they have been shut down. Subsequently, if the engine temperature exceeds the third engine temperature threshold before the second threshold EGR fraction is exceeded, the first priority outlet may be turned off as discussed above based on the third engine temperature threshold being exceeded rather than because the unmetered EGR exceeds the second threshold EGR fraction. Other similar variations are also within the scope of the present disclosure.
Thus, as discussed with respect to FIG. 10, method 1000 allows for monitoring of unmetered EGR and engine temperature in situations where PttB mode is requested with reduced air exchange, and includes issuing an alert to the vehicle operator specific to reaching or exceeding a predetermined threshold related to engine ingestion of unmetered EGR and engine temperature. In this way, a reliable power supply to the external load may be achieved, and in situations where such a reliable power supply to the external load may be compromised, mitigating actions may be taken quickly.
Thus, the methods discussed herein may include: in response to a request by an operator of a vehicle to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing a first alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a first threshold temperature; and controlling the cooling fan depending on whether the mitigating action is taken.
For this method, the first threshold temperature may comprise 50 ° f. In another example, the first threshold temperature may include a temperature in a range of 40 ° f to 60 ° f.
For such a method, the request by the operator to operate the engine to power one or more loads external to the vehicle may further include that the vehicle is stationary.
For such a method, the first alert requesting the operator to take mitigating action to reduce the engine temperature may include a request to open a hood of the vehicle.
For this method, controlling the cooling fan based on whether the mitigating action was taken may further comprise: maintaining the cooling fan off in response to the mitigating action having been taken, and enabling the cooling fan in response to the mitigating action not having been taken.
For this method, controlling the cooling fan based on whether the mitigating action was taken further comprises: controlling the cooling fan at a first speed in response to the mitigating action having been taken, and controlling the cooling fan at a second speed in response to the mitigating action not having been taken, wherein the first speed is lower than the second speed.
For such a method, in response to an indication that the engine temperature has reached a second threshold temperature greater than the first threshold temperature, the method may include: maintaining power to a first set of outlets that supply power to the one or more external loads, and interrupting power supply to a second set of outlets that supply power to the one or more external loads. In such an example, the first set of outlets may include outlets that supply a first voltage and the second set of outlets may include outlets that supply a second voltage, wherein the first voltage may be lower than the second voltage. Further, such examples may also include: in response to reaching a third threshold temperature that is greater than the second threshold temperature, discontinuing the supply of power to the first set of outlets that supply power to the one or more external loads.
Another example of a method may include: requesting, via a first alert, an operator of a vehicle to open a hood of the vehicle to reduce a temperature of an engine operating to power one or more loads external to the vehicle while the vehicle is stationary in response to the engine temperature reaching a first threshold temperature; and controlling a cooling fan to a first rotational speed in response to the hood being opened, and controlling the cooling fan to a second rotational speed in response to the hood not being opened.
For this method, the first rotational speed may include maintaining the cooling fan off, and wherein the second rotational speed varies according to a rate at which the engine temperature increases.
For such a method, the first rotational speed and the second rotational speed may be non-zero rotational speeds, and wherein the first rotational speed is lower than the second rotational speed.
For such a method, the method may further comprise: responsive to an engine temperature reaching a second threshold temperature, whether or not the hood has been opened by the vehicle operator, the second threshold temperature being greater than the first threshold temperature, maintaining power to a first set of outlets that supply power to the one or more external loads and interrupting power to a second set of outlets that supply power to the one or more external loads. In such an example, the method may further include: in response to an engine temperature reaching a third threshold temperature, discontinuing provision of power to the first set of outlets and effecting a shutdown of the engine. In another example, such a method may further comprise: issuing a second alert to notify the operator that the engine temperature is within a first threshold number of degrees of the second threshold temperature, wherein the second alert includes a first time range within which power to the second group of outlets is to be interrupted. In such an example, the method may further include: issuing a third alert to notify the operator that the engine temperature is within a second threshold number of degrees of the third threshold temperature, wherein the third alert includes a second time range within which power to the first group of outlets is to be interrupted.
Turning now to fig. 11, an
At time t0, the engine is in operation (curve 1105) and the vehicle is stopped (curve 1110). The hood is closed (curve 1150) and the engine cooling fan is off (curve 1155). The condition for reduced air exchange has not been determined (curve 1120). PttB mode has not been requested (curve 1115), and therefore, PttB mode input has not been requested (curve 1125) or received (curve 1130).
At time t1, a condition for reduced air exchange is determined (curve 1120). Thus, it can be appreciated that at time t0, the vehicle has just stopped, and by time t1, the controller has determined that the reduction in GPS signals is greater than a threshold amount and/or has inferred that the vehicle is in a reduced air exchange condition depending on the learned travel routines stored at the controller.
At time t2, the PttB engine operating mode is requested via the vehicle operator (curve 1115). In other words, at time t2, the vehicle operator has selected the PttB mode via the vehicle dashboard, and further may have selected an engine speed at which the engine is operable for operation in the PttB mode of operation. Thus, at time t3, a PttB mode input is requested (curve 815). Specifically, at time t3, as indicated by the vehicle being in a reduced air exchange condition, the vehicle controller initiates an alert requesting an operator input to continue PttB mode. In this exemplary timeline, although not explicitly shown, it is understood that the alerts include audible alerts requesting vehicle operator input, and additionally include text-based alerts displayed on a screen associated with a vehicle dashboard.
In response to the request for operator input at time t3, at time t4, the controller receives operator input. In particular, in this exemplary timeline, it can be appreciated that the vehicle operator has entered into the screen, on the dashboard, the desire to maintain the engine in operation for powering external electrical loads, even though the vehicle has been understood to be in a reduced air exchange environment via the alert provided to the vehicle operator.
Between times t4 and t5, the engine operates in PttB mode and power is supplied to one or more external loads via such operation. Although not explicitly shown, it can be appreciated that similar to that depicted by the timeline of FIG. 9, as the EGR fraction increases, the duty cycle of the EGR valve (e.g., 253) can be decreased to compensate for the unmetered EGR ingested by the engine, and the spark timing can be advanced as discussed above to similarly compensate for the increase in EGR fraction. In this exemplary timeline, it can be appreciated that taking such action maintains the EGR fraction below a first threshold EGR fraction represented by line 1136 (see curve 1135), and thus in this exemplary timeline, no warning is issued regarding taking mitigating action to improve air exchange in the vicinity of the vehicle.
However, between times t4 and t5, the engine temperature increases, and at time t5, it is indicated that the engine temperature (see curve 1140) has reached the first engine temperature threshold represented by
At time t6, the hood is opened. With the hood open, the engine temperature remains below the second engine temperature threshold between times t6 and t7, and thus, the cooling fan remains off (curve 1155). It will be appreciated that the action of opening the hood allows to improve the air circulation between the ambient air and the engine compartment, so that the use of cooling fans is avoided in this particular case. By avoiding the use of cooling fans, fuel economy may be improved.
At time t7, PttB mode is no longer requested (curve 1115). For example, in this exemplary timeline, the vehicle operator requests interruption of PttB mode via a touch screen associated with the vehicle dashboard. Thus, with the vehicle stationary and PttB mode no longer being requested, the engine is shut off via discontinuing fuel to the engine cylinders (curve 1105). Then, at time t8, the vehicle operator closes the hood (curve 1155).
Turning now to FIG. 12, an example real-time display 1200 is depicted that illustrates the present disclosure's real-time parameters being obtained via a controller and then sent to a software application that displays the real-time display on a screen associated with a vehicle dashboard (e.g., a Ford Sync screen). In some examples, additionally or alternatively, the controller may send such real-time parameters to a software application operating on a vehicle operator's computing device, including but not limited to a smartphone, laptop computer, tablet computer, or the like. In this way, such real-time parameters are still available for the vehicle operator to view without the vehicle operator being in the cabin of the vehicle. Real-time, as discussed herein, refers to the controller processing data retrieved from one or more sensors as discussed above in milliseconds and sending the data to a software application to display information via a real-time display so that the data is substantially immediately viewable by a vehicle operator.
As discussed above with respect to the methods of fig. 4 and 9, the alert may be communicated to the vehicle operator visually or audibly. Thus, in one example, the visual alert may be communicated to the vehicle operator via the message center 1205. It will be appreciated that in some examples, an audible message may additionally be communicated to the vehicle operator for use in issuing a particular alert. In some examples, message centers 1205 may include the
An exemplary alert is depicted at message center 1205 alerting the vehicle operator that the first engine temperature threshold has been exceeded and that the vehicle's controller is requesting that the vehicle operator open the hood for engine cooling purposes. In some examples, such an alert may include a message center flashing (e.g., a series of several flashes from one color to another, or flashes of the same color but different intensity levels) to draw the attention of the vehicle operator to the alert. Additionally or alternatively, such alerts may include vehicle interior lights and/or exterior lights (e.g., headlamps) flashing in a particular sequence, which may be interpreted as an indication to inspect the message center via the vehicle operator. Additionally or alternatively, such an alert may include a horn of the vehicle sounding in a particular pattern to draw the attention of the vehicle operator to the message center. Additionally or alternatively, where an alert is sent to the vehicle operator's computing device, the computing device may emit a sound that notifies the vehicle operator of the alert, or may vibrate or the like to draw the vehicle operator's attention to the message center.
Where the alert includes a request for vehicle operator input, the input may be communicated to the vehicle controller via several means. As one example, the vehicle operator may press one or more of the brake and/or accelerator pedals in a predetermined pattern to provide the input to the controller. Additionally or alternatively, the vehicle operator may provide the requested input via pressing a button or other actuator associated with a power seat of the vehicle, a particular predetermined button or other actuator associated with a door of the vehicle, a particular predetermined button or other actuator associated with a steering wheel of the vehicle, or the like. Additionally or alternatively, input may be directly communicated through a real-time display, where the real-time display is displayed on a touch screen (e.g., a Ford Sync screen).
In some examples, real-time display 1200 may include an unmetered EGR fraction panel 1210. The unmetered EGR fraction panel 1210 may include an unmetered EGR curve 1212 that may display the amount of unmetered EGR ingested by the engine ([ EGR ]) over time in real-time relative to the first threshold EGR fraction (referring to step 460 of method 400) and the second threshold EGR fraction (referring to step 475 of method 400). In the event that the first threshold EGR fraction is exceeded and the first EGR fraction alert is issued (see step 465 of method 400), the controller may send to the software application a "yes" sign a fill query "issue a first alert? "is used herein. As discussed above with respect to fig. 4, where the first alert is issued, the alert may include information requesting feedback as to whether mitigating action has been taken to increase the flow of air in the vicinity of the vehicle. In response to the mitigating action having been taken (e.g., the vehicle operator opens a window, door, etc.), the vehicle operator may communicate to the controller the fact that the mitigating action has been taken in any of the manners described above for communicating the action. Then, the controller may send to the software application a "yes" designation fill query "mitigation action? "is used herein. As depicted for illustrative purposes, the unmetered EGR fraction shown at the unmetered EGR curve 1212 remains below the first threshold EGR fraction and, as such, indicates that neither the first nor second alert was issued, and indicates that no mitigating action was taken to increase the air flow proximate the vehicle. By providing real-time monitoring of the unmetered EGR fraction relative to the first and second threshold EGR fractions, the vehicle operator may take mitigating action or prepare to take mitigating action prior to issuing an actual alert. Such a display may improve vehicle operator satisfaction as opposed to a situation where the vehicle operator does not know how close the unmetered EGR fraction is to the first threshold EGR fraction or the second threshold EGR fraction in fact.
In some examples, additionally or alternatively, the real-time display 1200 may include an engine temperature panel 1215. The engine temperature panel 1215 may include an engine temperature profile 1218 that may display the temperature of the engine in real-time relative to a first engine temperature threshold (see step 930 of the method 900), a second engine temperature threshold (see step 955 of the method 900), and a third engine temperature threshold (see step 990 of the method 900). In this exemplary illustration, it is indicated that the engine temperature has exceeded the first engine temperature threshold, and thus that a first alert has been issued (for the query "issue first alert. However, because neither the second nor third engine temperature thresholds have been reached, the indication has not yet been alerted to such a condition. In addition, information regarding the status (open or closed) of the vehicle hood is included at the engine temperature panel 1215. In this exemplary illustration, in response to the first engine temperature threshold having been reached, a warning is issued to the vehicle operator requesting a mitigating action in the form of opening the hood, and in this example, the hood has been opened and such information is displayed at the engine temperature panel. In some examples, the indication relating to the hood status may be populated in response to an input to the software application via the vehicle operator confirming that the hood has been opened. In other examples, the controller may detect the fact that the hood has been opened, and may then send a signal to the software application to fill an "open" flag associated with the query regarding the hood status.
In some examples, the real-time display may also include a "time to empty" panel 1220. The remaining fuel travelable time panel 1220 may include hours, minutes, and seconds until the fuel in the fuel tank is depleted. The time to empty panel 1220 may take into account engine speed, engine load, and fuel level, and extrapolate the time to empty determination based on such parameters. When such parameters change, the remaining fuel travelable time determination may be adjusted accordingly. It will be appreciated that while depicted as part of the real time display 1200, in other examples, the remaining fuel travelable time may additionally or alternatively be displayed, for example, where the vehicle operator is provided with a "miles travelable" indication at one location on the vehicle dashboard. It will be appreciated that because the vehicle is stationary, the "remaining fuel miles-capable" message may not be applicable and may not be relevant, and thus, when operating in the PttB mode, the "remaining fuel miles-capable" displayed at the vehicle dashboard may be switched to indicate the "remaining fuel miles-capable time". By displaying the amount of time until the vehicle's fuel tank is depleted, the vehicle operator can more easily assess whether to continue operating in PttB mode or to discontinue PttB mode operation. Although not explicitly shown, it is understood that in some examples, there may be a first time to empty threshold and a second time to empty threshold. As one example, the first time to empty threshold may include 20 minutes and the second time to empty threshold may include 10 minutes. Such examples are intended to be illustrative. For example, if the remaining fuel travelable time calculation falls below the first remaining fuel travelable time threshold, a first fuel level alert may be communicated to the vehicle operator in any one or more of the manners described above that alerts the vehicle operator to the amount of time remaining until the fuel in the fuel tank is depleted so that the vehicle operator may take mitigating actions, such as disconnecting the external load from the power supply tank and/or turning off PttB mode and interrupting engine operation. If the first fuel level alert is issued but no mitigating action is taken such that the time to empty calculation falls below the second time to empty threshold, then a second fuel level alert may be issued indicating that the engine is turned off in order to conserve fuel sufficient for propulsion of the vehicle to the fueling station.
In some examples, the first time to empty threshold and the second time to empty threshold may be adjustable. For example, the vehicle controller may retrieve information related to the shortest distance from the location at which the vehicle is parked to a nearby refueling station. Such information may be determined in connection with the in-vehicle navigation system, via V2V and/or V2I communications, from information retrieved from learned travel routines, and so forth. The first and second time to empty thresholds may be adjusted upward as the shortest distance from the nearest refueling station increases, and the first and second time to empty thresholds may be adjusted downward as the shortest distance from the nearest refueling station decreases. Specifically, in this example, the upward adjustment refers to setting the first and second remaining fuel travelable time thresholds to larger remaining fuel travelable times than the downward adjustment, which refers to setting the first and second remaining fuel travelable time thresholds to smaller remaining fuel travelable times. As a particular example, the upward adjustment may include adjusting the first time to empty threshold from 20 minutes to 30 minutes, and the downward adjustment may include adjusting the first time to empty threshold from 20 minutes to 15 minutes. In this way, based on the estimated amount of fuel needed to reach the nearest refueling station, an alert may be issued and engine shut-down may be controlled.
In some examples, the real-time display may include an engine speed panel 1225. The engine speed panel 1225 may display the current engine speed and may allow touch-based modification of the speed at which the engine is controlled if the real-time display is displayed on a touch screen. For example, a pull-down panel (not specifically shown) from the engine speed panel 1225 may be used to adjust engine speed for operating the engine in PttB mode. Inputting the desired engine speed into the engine speed panel 1225 may be implemented in any manner known in the art for inputting a desired value into a software application.
In some examples, the real-time display may also include a power generation level panel 1230. The power generation panel 1230 may provide a real-time display of the power level provided to the power supply box as a percentage of the maximum level. For example, as discussed above, unmetered EGR and/or engine temperature may result in less efficient power generation, and it may be desirable for a vehicle operator to readily know the current power generation level from a maximum value. In this way, in some examples, a vehicle operator may selectively select which external loads to keep powered and which to discontinue use.
In this way, engine operation may be controlled to supply power to a power supply box, which in turn supplies power to one or more external loads, in the event of a request for PttB mode occurring under reduced air exchange conditions. By employing the use of thresholds and warnings relating to one or more of the unmetered EGR introduced into the engine and/or the engine temperature, a consistent level of power delivered to the external load may be achieved. In particular, the vehicle operator may take mitigating action in response to alerts based on the threshold to ensure consistent power levels, and may automatically shut down the engine to avoid undesirable problems with engine degradation and/or external loads receiving degraded power supply in the event that significant power degradation may occur due to engine stability issues related to increased temperature and/or the introduction of unmetered EGR.
The technical effect is to recognize that in some situations, it may be desirable for a vehicle operator to operate the engine during conditions of reduced air exchange in order to power an external load, and by using a combination of thresholds and warnings, the PttB mode may be reliably used in such situations. For example, a technical effect is to recognize that when a vehicle operator makes a request for PttB mode, it may be desirable to indicate whether the vehicle is in a reduced air exchange condition, and to request input from the vehicle operator specifying such a condition and confirming the desire to continue. Thus, the technical effect is to recognize that without such confirmation, the engine may be shut down to avoid problems with power generation and engine stability that may occur when using the PttB mode with reduced air exchange. A further technical effect is the recognition that there may be several methods of monitoring the unmetered EGR when the vehicle is stationary and operating under reduced air exchange conditions, as depicted above at fig. 4-7. A further technical effect is that it is recognized that in some examples, with a vehicle operating in PttB mode, it may be desirable to selectively turn off the second priority outlet for powering an external load (while maintaining the first priority outlet active) when a particular level of unmetered EGR is detected and/or when a particular engine temperature is reached. A further technical effect is the recognition that by communicating relevant parameters related to PttB mode operation (e.g., unmetered EGR level, engine temperature, time before fuel depletion in the fuel tank, engine speed, current power output as a percentage of maximum power output, and a message) via a real-time display, a vehicle operator may be informed in advance as to whether conditions are such that power generation degradation may occur, which may enable the vehicle operator to take mitigating actions that they deem appropriate.
Thus, the systems described herein with reference to fig. 1-2, along with the methods described herein with reference to fig. 3-7 and 9-10, may implement one or more systems and one or more methods. In one example, a method comprises: in response to a request by an operator of a vehicle to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing a first alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a first threshold temperature; and controlling the cooling fan depending on whether the mitigating action is taken. In a first example of the method, the method further comprises: wherein the first threshold temperature comprises 50 ° f. A second example of the method optionally includes the first example, and further comprising: wherein the first threshold temperature comprises a temperature in a range of 40F to 60F. A third example of the method optionally includes any one or more or each of the first to second examples, and further comprising: wherein the request by the operator to operate the engine to power one or more loads external to the vehicle further comprises the vehicle being stationary. A fourth example of the method optionally includes any one or more or each of the first to third examples, and further comprising: wherein the first alert requesting the operator to take mitigating action to reduce the engine temperature comprises a request to open a hood of the vehicle. A fifth example of the method optionally includes any one or more or each of the first to fourth examples, and further comprising: wherein controlling the cooling fan according to whether the mitigation action is taken further comprises: maintaining the cooling fan shut down in response to the mitigating action having been taken; and activating the cooling fan in response to the mitigation action not having been taken. A sixth example of the method optionally includes any one or more or each of the first to fifth examples, and further comprising: wherein controlling the cooling fan according to whether the mitigation action is taken further comprises: controlling the cooling fan at a first speed of rotation in response to the mitigating action having been taken; and controlling the cooling fan at a second speed in response to the mitigating action not having been taken, wherein the first speed is lower than the second speed. A seventh example of the method optionally includes any one or more or each of the first to sixth examples, and further comprising: an indication that the engine temperature has reached a second threshold temperature greater than the first threshold temperature; maintaining power to a first set of outlets that supply power to the one or more external loads; and interrupting the supply of power to a second set of outlets supplying power to the one or more external loads. An eighth example of the method optionally includes any one or more or each of the first to seventh examples, and further comprising: wherein the first set of outlets comprises outlets supplying a first voltage, and wherein the second set of outlets comprises outlets supplying a second voltage, wherein the first voltage is lower than the second voltage. A ninth example of the method optionally includes any one or more or each of the first to eighth examples, and further comprising: in response to reaching a third threshold temperature that is greater than the second threshold temperature, discontinuing the supply of power to the first set of outlets that supply power to the one or more external loads.
Another example of a method includes: requesting, via a first alert, an operator of a vehicle to open a hood of the vehicle to reduce a temperature of an engine operating to power one or more loads external to the vehicle while the vehicle is stationary in response to the engine temperature reaching a first threshold temperature; and controlling a cooling fan to a first rotational speed in response to the hood being opened, and controlling the cooling fan to a second rotational speed in response to the hood not being opened. In a first example of the method, the method further comprises: wherein the first rotational speed comprises maintaining the cooling fan off; and wherein the second rotational speed varies in accordance with a rate at which the engine temperature increases. A second example of the method optionally includes the first example, and further comprising: wherein the first rotational speed and the second rotational speed are non-zero rotational speeds; and wherein the first rotational speed is lower than the second rotational speed. A third example of the method optionally includes any one or more or each of the first to second examples, and further comprising: responsive to an engine temperature reaching a second threshold temperature regardless of whether the hood has been opened by the vehicle operator, the second threshold temperature being greater than the first threshold temperature; maintaining power to a first set of outlets supplying power to the one or more external loads and interrupting power supplied to a second set of outlets supplying power to the one or more external loads. A fourth example of the method optionally includes any one or more or each of the first to third examples, and further comprising: in response to an engine temperature reaching a third threshold temperature, discontinuing provision of power to the first set of outlets and effecting a shutdown of the engine. A fifth example of the method optionally includes any one or more or each of the first to fourth examples, and further comprising: issuing a second alert to notify the operator that the engine temperature is within a first threshold number of degrees of the second threshold temperature, wherein the second alert includes a first time range within which power to the second group of outlets is to be interrupted. A sixth example of the method optionally includes any one or more or each of the first to fifth examples, and further comprising: issuing a third alert to notify the operator that the engine temperature is within a second threshold number of degrees of the third threshold temperature, wherein the third alert includes a second time range within which power to the first group of outlets is to be interrupted.
An example of a system for a vehicle includes: an engine capable of driving a generator to provide power to a power box, which in turn supplies power to one or more external loads; one or more temperature sensors for monitoring engine temperature; a warning system for communicating a visual and/or audible warning to an operator of the vehicle; and a controller having computer readable instructions stored on non-transitory memory that, when executed while the vehicle is stationary and in a parked state and while the engine is combusting air and fuel to provide power to the power supply box to power the one or more external loads, cause the controller to: monitoring the engine temperature via the one or more temperature sensors, and in response to the engine temperature reaching a first threshold temperature, issuing a first alert requesting the operator of the vehicle to take mitigating action to reduce the engine temperature while maintaining power to the one or more external loads. In a first example of the system, the system further comprises: wherein the one or more temperature sensors monitor cylinder head temperature of one or more cylinders of the engine, and wherein the one or more temperature sensors are communicably coupled to one or more circuit breakers of one or more outlets of the power supply box, the one or more outlets including a first set of outlets and a second set of outlets; and wherein the controller stores further instructions for: maintaining power to the first set of outlets while discontinuing provision of power to the second set of outlets in response to the engine temperature reaching a second threshold temperature greater than the first threshold temperature, and discontinuing provision of power to the first set of outlets in response to the engine temperature reaching a third threshold temperature greater than the second threshold temperature; and wherein when the engine temperature is within a first threshold degree of the second threshold temperature, a second alert is issued to notify the operator that power to the second set of outlets is about to be interrupted, and wherein when the engine temperature is within a second threshold degree of the third threshold temperature, a third alert is issued to notify the operator that power to the third set of outlets is about to be interrupted. A second example of the system optionally includes the first example, and further comprising: a fan for cooling the engine, and wherein the controller stores further instructions for: differentially controlling the speed of the cooling fan depending on whether the mitigating action has been taken to reduce the engine temperature, wherein the mitigating action includes opening a hood of the vehicle.
In another embodiment, a method comprises: in response to a request to operate an engine of a vehicle to power one or more external loads while the vehicle is stationary, and further in response to an indication that the vehicle is in a reduced air exchange condition, power is supplied to the one or more loads via engine operation, one or more parameters related to an unmetered exhaust gas level and an engine temperature drawn into the engine are retrieved in real-time, and the parameters are sent to a real-time display for viewing by the vehicle operator. In one example, the real-time display is associated with a vehicle dashboard located within a cabin of the vehicle. Additionally or alternatively, the real-time display is displayed on a computing device used by the vehicle operator, such as a smart phone, laptop computer, tablet computer, or the like. The real-time display may include thresholds related to the level of unmetered exhaust gas introduced into the engine and may include other thresholds related to engine temperature. In this way, the vehicle operator may monitor the unmetered exhaust level introduced into the engine in real time relative to a particular threshold, which may enable mitigating actions to be taken by the vehicle operator based on such information. Similarly, the vehicle operator may monitor engine temperature in real-time relative to a particular threshold, which may enable mitigating actions to be taken by the vehicle operator based on such information. In this method, the method may further include: displaying in real time a parameter related to a duration until it is inferred that the fuel in the fuel tank will be depleted. In this method, the method may further include: parameters related to the current engine speed for operation in PttB mode are displayed in real time.
In yet another embodiment, a method comprises: in a first condition comprising a request to operate a vehicle in PttB mode, engine operation is controlled in accordance with a level of exhaust gas drawn into the engine through an intake passage and in accordance with a temperature of the engine, and in a second condition engine operation is controlled in accordance with the temperature of the engine and not the level of exhaust gas drawn into the engine through the intake passage. In this method, the first condition includes an indication that the vehicle is in a reduced air exchange position and the second condition includes an indication that the vehicle is not in a reduced air exchange position.
It should be noted that the exemplary control and estimation routines included herein may be used with various engine and/or vehicle system configurations. The control methods and routines disclosed herein may be stored as executable instructions in a non-transitory memory and may be implemented by a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific routines described herein may represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and the like. As such, various acts, operations, and/or functions illustrated may be performed in the sequence illustrated, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the illustrated acts, operations, and/or functions may be repeatedly performed depending on the particular strategy being used. Further, the described acts, operations, and/or functions may visually represent code to be programmed into the non-transitory memory of a computer readable storage medium in an engine control system, wherein the described acts are implemented by executing instructions in conjunction with an electronic controller in a system comprising various engine hardware components.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above techniques may be applied to V6 cylinders, inline 4 cylinders, inline 6 cylinders, V12 cylinders, opposed 4 cylinders, and other engine types. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
As used herein, the term "about" is to be construed to mean plus or minus five percent of the range, unless otherwise specified.
The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to "an" element or "a first" element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
According to the invention, a method comprises: in response to a request by an operator of a vehicle to operate an engine to supply power to one or more loads external to the vehicle, monitoring an engine temperature and issuing a first alert requesting the operator to take a mitigating action to reduce the engine temperature when the engine temperature reaches a first threshold temperature; and controlling the cooling fan depending on whether the mitigating action is taken.
According to one embodiment, the first threshold temperature comprises 50 ° f.
According to one embodiment, the first threshold temperature comprises a temperature in the range of 40 ° f to 60 ° f.
According to one embodiment, the request by the operator to operate the engine to power one or more loads external to the vehicle further comprises that the vehicle is stationary.
According to one embodiment, the first alert requesting the operator to take mitigating action to reduce the engine temperature comprises a request to open a hood of the vehicle.
According to one embodiment, controlling the cooling fan in dependence on whether the mitigating action was taken further comprises: maintaining the cooling fan shut down in response to the mitigating action having been taken; and activating the cooling fan in response to the mitigation action not having been taken.
According to one embodiment, controlling the cooling fan in dependence on whether the mitigating action was taken further comprises: controlling the cooling fan at a first speed of rotation in response to the mitigating action having been taken; and controlling the cooling fan at a second rotational speed in response to the mitigating action not having been taken, wherein the first rotational speed is lower than the second rotational speed.
According to one embodiment, the invention is further characterized in that: maintaining power to a first set of outlets that supply power to the one or more external loads in response to an indication that the engine temperature has reached a second threshold temperature that is greater than the first threshold temperature; and interrupting the supply of power to a second set of outlets supplying power to the one or more external loads.
According to one embodiment, the first set of outlets comprises outlets supplying a first voltage, and wherein the second set of outlets comprises outlets supplying a second voltage, wherein the first voltage is lower than the second voltage.
According to one embodiment, the invention is further characterized in that: in response to reaching a third threshold temperature that is greater than the second threshold temperature, discontinuing the supply of power to the first set of outlets that supply power to the one or more external loads.
According to the invention, a method comprises: requesting, via a first alert, an operator of a vehicle to open a hood of the vehicle to reduce a temperature of an engine operating to power one or more loads external to the vehicle while the vehicle is stationary in response to the engine temperature reaching a first threshold temperature; and controlling a cooling fan to a first rotational speed in response to the hood being opened, and controlling the cooling fan to a second rotational speed in response to the hood not being opened.
According to one embodiment, the first rotational speed includes maintaining the cooling fan off; and wherein the second rotational speed varies in accordance with a rate at which the engine temperature increases.
According to one embodiment, the first rotational speed and the second rotational speed are non-zero rotational speeds; and wherein the first rotational speed is lower than the second rotational speed.
According to one embodiment, the invention is further characterized in that: responsive to an engine temperature reaching a second threshold temperature, whether or not the hood has been opened by the vehicle operator, the second threshold temperature being greater than the first threshold temperature, maintaining power to a first set of outlets that supply power to the one or more external loads, and interrupting power to a second set of outlets that supply power to the one or more external loads.
According to one embodiment, the invention is further characterized in that: in response to an engine temperature reaching a third threshold temperature, discontinuing provision of power to the first set of outlets and effecting a shutdown of the engine.
According to one embodiment, the invention is further characterized in that: issuing a second alert to notify the operator that the engine temperature is within a first threshold number of degrees of the second threshold temperature, wherein the second alert includes a first time range within which power to the second group of outlets is to be interrupted.
According to one embodiment, the invention is further characterized in that: issuing a third alert to notify the operator that the engine temperature is within a second threshold number of degrees of the third threshold temperature, wherein the third alert includes a second time range within which power to the first group of outlets is to be interrupted.
According to the invention, a system for a vehicle is provided, having: an engine capable of driving a generator to provide power to a power box, which in turn supplies power to one or more external loads; one or more temperature sensors for monitoring engine temperature; a warning system for communicating a visual and/or audible warning to an operator of the vehicle; and a controller having computer readable instructions stored on non-transitory memory that, when executed while the vehicle is stationary and in a parked state and while the engine is combusting air and fuel to provide power to the power supply box to power the one or more external loads, cause the controller to: monitoring the engine temperature via the one or more temperature sensors, and in response to the engine temperature reaching a first threshold temperature, issuing a first alert requesting the operator of the vehicle to take mitigating action to reduce the engine temperature while maintaining power to the one or more external loads.
According to one embodiment, the one or more temperature sensors monitor cylinder head temperature of one or more cylinders of the engine, and wherein the one or more temperature sensors are communicably coupled to one or more circuit breakers of one or more outlets of the power supply box, the one or more outlets including a first set of outlets and a second set of outlets; and wherein the controller stores further instructions for: maintaining power to the first set of outlets while discontinuing provision of power to the second set of outlets in response to the engine temperature reaching a second threshold temperature greater than the first threshold temperature, and discontinuing provision of power to the first set of outlets in response to the engine temperature reaching a third threshold temperature greater than the second threshold temperature; and wherein when the engine temperature is within a first threshold degree of the second threshold temperature, a second alert is issued to notify the operator that power to the second set of outlets is about to be interrupted, and wherein when the engine temperature is within a second threshold degree of the third threshold temperature, a third alert is issued to notify the operator that power to the first set of outlets is about to be interrupted.
According to one embodiment, the invention is further characterized in that: a fan for cooling the engine, and wherein the controller stores further instructions for: differentially controlling the speed of the cooling fan depending on whether the mitigating action has been taken to reduce the engine temperature, wherein the mitigating action includes opening a hood of the vehicle.
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