阅读说明：本技术 用于控制混合动力车辆的驾驶性能的控制器和方法
(Controller and method for controlling drivability of hybrid vehicle
) 是由 J.比斯特
M.S.帕马 于 2019-08-27 设计创作，主要内容包括：本文中的各种实施例提供一种用于控制混合动力车辆的驾驶性能的控制器110和方法。所述车辆依赖于输出转矩(o)驱动,所述输出转矩(o)对应于包括内燃(IC)发动机106和辅助发动机102的至少两个发动机的所产生的输出。控制器110被配置成根据参考转矩(r)、驾驶员需求(d)、比例增益126和时间常数124计算控制变量(y)。控制器110基于所述控制变量(y)和所述参考转矩(r)计算所述输出转矩(o),并且基于所述控制变量(y)控制致动器130以获得所述输出转矩(o)并且从而控制所述车辆的所述驾驶性能。控制器110通过仅根据驾驶员请求的需求提供滤波来实现平滑的驾驶性能。(Various embodiments herein provide a controller 110 and method for controlling drivability of a hybrid vehicle. The vehicle is driven in dependence on an output torque (o) corresponding to the resulting output of at least two engines including an Internal Combustion (IC) engine 106 and an auxiliary engine 102. The controller 110 is configured to calculate a control variable (y) based on the reference torque (r), the driver demand (d), the proportional gain 126, and the time constant 124. The controller 110 calculates the output torque (o) based on the control variable (y) and the reference torque (r), and controls the actuator 130 based on the control variable (y) to obtain the output torque (o) and thereby control the drivability of the vehicle. The controller 110 achieves smooth drivability by providing filtering only according to the demand requested by the driver.)
1. A controller (110) for controlling drivability of a hybrid vehicle, the vehicle being driven in dependence on an output torque (o) corresponding to a resulting output of at least two engines including an Internal Combustion (IC) engine (106) and an auxiliary engine (102), the controller (110) being configured to:
calculating a control variable (y) based on the reference torque (r), the driver demand (d), the proportional gain (126) and the time constant (124),
calculating the output torque (o) based on the control variable (y) and the reference torque (r), and
controlling an actuator (130) based on the control variable (y) to obtain the output torque (o) and thereby control the drivability.
2. The controller (110) of claim 1, wherein prior to the calculation of the control variable (y), the time constant 124 is back-calculated from at least the proportional gain 126 and the reference torque (r) such that the output torque (o) yields the same value as in the previous calculation step.
3. The controller (110) of claim 2, wherein the back-calculation is performed when either of the proportional gain (126) and the reference torque (r) is varied.
4. The controller (110) of claim 1, comprising a proportional module (112) for processing the proportional gain (126) and an integration module (114) for processing the time constant (124), wherein the integration module (114) is a low pass filter.
5. The controller (110) of claim 1, wherein the actuator (130) is at least one selected from the group consisting of: fuel injectors, spark plugs, throttle actuators, Exhaust Gas Recirculation (EGR) valves, and Variable Valve Trains (VVTs).
6. A method for controlling drivability of a hybrid vehicle, the vehicle being driven in dependence on an output torque (o) corresponding to a resulting output of at least two engines including an Internal Combustion (IC) engine (106) and an auxiliary engine (102), the method comprising the steps of:
calculating, by the controller (110), a control variable (y) from the reference torque (r), the driver demand (d), the proportional gain (126) and the time constant (124);
calculating, by the controller (110), the output torque (o) based on the control variable (y) and the reference torque (r), and controlling, by the controller (110), an actuator (130) based on the control variable (y) to obtain the output torque (o) and thereby control the drivability of the vehicle.
7. A method according to claim 6, wherein, before calculating the control variable (y), the time constant (124) is back-calculated from at least the proportional gain (126) and the reference torque (r) so that the output torque (o) yields the same value as in the previous calculation step.
8. The method of claim 7, wherein the recalculation is performed when either of the proportional gain 126 and the reference torque (r) is changed.
9. The method of claim 6, comprising a proportional module (112) for processing the proportional gain (126) and an integration module (114) for processing the time constant (124), wherein the integration module (114) is a low pass filter.
10. The method of claim 6, wherein the actuator (130) is at least one selected from the group consisting of: fuel injectors, spark plugs, throttle actuators, Exhaust Gas Recirculation (EGR) valves, and Variable Valve Trains (VVTs).
Technical Field
The present invention relates to a controller and a method for controlling drivability of a vehicle.
Background
According to the prior art DE102004032343, a method for controlling a process in an internal combustion engine is disclosed. The method for controlling a process in an internal combustion engine requires the calculation of a control variable (y) in dependence on at least one first and one second parameter. Before calculating the control variable, the back-calculation of the time constant at least starting from the proportional gain and the control variable takes place as follows: the same control variables are generated as in the previous calculation stage. The calculation of the control variables is effected at least from the proportional gain and from the time constant obtained from the inverse calculation. The independent claim is included for an arrangement for controlling a process in an internal combustion engine by means of the proposed method.
Drawings
Embodiments of the present disclosure are described with reference to the following drawings:
FIG. 1 shows a detailed block diagram of a system for controlling drivability of an IC engine in a hybrid vehicle according to an embodiment of the invention;
fig. 2 shows a basic system diagram of a hybrid vehicle according to an embodiment of the invention;
FIG. 3 illustrates a method for controlling drivability of an IC engine in a hybrid vehicle according to the present disclosure;
fig. 4 illustrates a detailed method of controlling drivability according to an embodiment of the present invention;
FIG. 5 illustrates different scenarios of drivability control according to embodiments of the invention;
FIG. 6 illustrates the operation of the present invention by waveforms, according to an embodiment of the present invention, and
FIG. 7 illustrates an analysis of drivability with and without a controller by a waveform according to an embodiment of the invention.
Detailed Description
Fig. 1 shows a detailed block diagram of a system for controlling drivability of an IC engine in a hybrid vehicle according to an embodiment of the invention. The controller 110 controls drivability of the hybrid vehicle. The vehicle is driven in dependence on an output torque (o) corresponding to the resulting output of at least two engines including an Internal Combustion (IC) engine 106 and an auxiliary engine 102. The controller 110 is configured/adapted to calculate a control variable (y) based on the reference torque (r), the driver demand (d), the proportional gain 126 and the time constant 124. The controller 110 calculates a requested output torque (o) based on the control variable (y) and the reference torque (r), and then controls the actuator 130 based on the control variable (y) to obtain the output torque (o) and thereby control the drivability of the vehicle. The IC engine 106 operates on any of gasoline, diesel, flex fuel, Compressed Natural Gas (CNG), and other types of fuel.
Prior to the calculation of the control variable (y), the controller 110 back-calculates the time constant 124 based on at least the proportional gain 126 and the reference torque (r) so that the output torque (o) yields the same value as in the previous calculation step. The back-calculation/re-calculation is performed when there is a change in either of the proportional gain 126 and the reference torque (r).
The controller 110 includes a proportional module 112 and an integral module 114. The scaling module 112 processes the scaling gain 126. The integration module 114 processes the time constant 124. The integration module 114 is a low pass filter. The proportional module 112 and the integral module 114 may be adapted as programs or as separate hardware circuits. The control variable (y) is, for example, the fuel quantity and/or the air supply required for controlling the IC engine 106.
The operation of the invention with respect to fig. 1 is explained. When the driver presses the accelerator pedal 122, which indicates a driver demand (d), then the driver demand (d) is split into a demand request or reference torque (r) for the auxiliary engine 102 and a demand request for the IC engine 106 based on the operating strategy 120. The operating policy 120 is implemented/executed by a separate control unit or by the controller 110 itself. The system limits 116 are applied to the demand request for the IC engine 106 ICE at junction 118 to form the final limited demand or engine demand (x). Various vehicle or system parameters, such as engine speed, vehicle speed, gear position, etc., are detected or sensed using different sensors 128. Based on various system conditions identified from the sensors 128, the proportional gain 126 is calculated according to a predefined look-up table. The controller 110 calculates a first portion of the control variable (y) based on the proportional gain 126 and the engine demand (x). The first portion is calculated by the scaling module 112 of the controller 110. The time constant 124 is calculated using the inverse of the control state detected by the sensor 128, the reference torque (r), and the proportional gain 126. The integration module 114 is then used to process the engine demand (x) along with the time constant 124 to produce a second portion of the control variable (y). The proportional gain 126 and the time constant 124 are calculated by a separate control unit or by the same controller 110. The separate control unit (if used) communicates with the controller 110 to provide values for the proportional gain 126 and the time constant 124. Both the first and second portions of the controlled variable (y) are combined at a junction 108 to form the controlled variable (y). Controller 110 actuates actuator 130 to achieve the control variable (y) via IC engine 106. The outputs of both the IC engine 106 and the auxiliary engine 102 are combined at the junction 104 to produce the output torque (o) of the system/vehicle.
The actuator 130 is at least one selected from the group consisting of: fuel injectors, spark plugs, throttle actuators, Exhaust Gas Recirculation (EGR) valves, and Variable Valve Trains (VVTs), among others. The fuel injector effects control of the fuel injection quantity. The spark plug implements control to advance or retard ignition of the air-fuel mixture. The throttle actuator effects control of the air amount. The EGR valve enables control of recirculation of exhaust gas at different operating points to assist drivability. VVT also enables control of intake and exhaust valves of the IC engine 106.
According to an embodiment of the invention, the controller 110 is a drivability filter which in principle is designed to provide filtering only for the driver demand (d). The controller 110 is a main drivability component in an Engine Control Unit (ECU). The controller 110 develops a torque demand on the IC engine 106 by providing filtering of the driver demand torque. In a hybrid system, the driver demand is split between the IC engine 106 and the auxiliary engine 102 due to the additional power source in the system. Due to the hybrid architecture and the various operating modes, the demands placed on the IC engine 106 may also vary, despite the constant driver demand (d). For example: charging of the battery in the hybrid vehicle results in an additional load on the IC engine 106, which is not driver demand (d). The drivability filter separates and provides filtering to only those changes that are relevant to the driver's needs.
Fig. 2 shows a basic system diagram of a hybrid vehicle according to an embodiment of the invention. The basic system diagram is indicated by reference numeral 200. The accelerator pedal 122 is an input device for specifying a driver demand (d). In the hybrid vehicle, the driver demand (d) is split into demands for the IC engine 106 and the auxiliary engine 102. The assist controller 220 processes the reference torque (r) of the assist engine 102 and the controller 110 processes the engine demand (x) for the IC engine 106. The combined output torque (o) is delivered to the wheels 210. The controller 110 is further illustrated by labels to describe internal units that work to calculate/compute the control variable (y). The proportional gain 126 and time constant 124 are shown by the corresponding boxes. The proportional gain 126 and the time constant 124 are processed by the proportional module 112 and the integral module 114, respectively, along with the engine demand (x).
Operation in the IC engine 106 is achieved by, but is not limited to, discrete-time implementation of control elements (i.e., the proportional module 112 and the integral module 114). Depending on the operating point of the system 200, the coefficients of the controller 110, parameters referred to as control elements (i.e., the proportional gain 126 and the time constant 124), are adapted to implement the actions of the controller 110. The controller 110 is also referred to as an active surge controller. When the control parameter is changed, a jump in the output torque (o) is observed. Similarly, when the IC engine 106 is used in a hybrid configuration, a change in the reference torque (r) causes a jump in the input to the control element. The jump or chatter is not observed on vehicles having only an IC engine 106 because the low pass filter filters the signal and then transmits it further. However, a jump is observed in a hybrid vehicle because the output from the auxiliary engine 102 has already been delivered, although filtering is performed on the engine demand, thus causing a judder/jump. The jump at the final output is not desired in a hybrid vehicle. For example, the reference torque (r) is changed while the driver demand (d) and the control parameters are kept unchanged.
According to an embodiment of the present invention, the controller 110 is provided only for filtering the driver demand (d) and controlling the corresponding engine demand accordingly. The controller 110 ignores the change in demand that occurs due to the electrical load in the hybrid vehicle.
According to an embodiment of the invention, the auxiliary engine 102 is any one of an electric machine (e.g., an electric motor) and a hydraulic machine (e.g., a hydraulic motor). In another embodiment, a third engine is used with the IC engine 106 and the auxiliary engine 102. In the case of three engines, the following combinations will be possible. One IC engine 106 and two electric machines, one IC engine 106 and two hydraulic machines, one IC engine 106 and one electric machine and one hydraulic machine, two IC engines 106 and one hydraulic machine, or two IC engines 106 and one electric machine.
Fig. 3 shows a method for controlling drivability of an IC engine in a hybrid vehicle according to the invention. A method for controlling drivability of a hybrid vehicle is provided. The vehicle is driven in dependence on an output torque (o) corresponding to the generated output of at least two engines including the IC engine 106 and the auxiliary engine 102. The method comprises the following steps: step 302, which includes calculating, by the controller 110, a control variable (y) based on the reference torque (r), the driver demand (d), the proportional gain 126, and the time constant 124. Step 304 includes calculating, by the controller 110, an output torque (o) based on the control variable (y) and the reference torque (r). Step 306 includes controlling, by the controller 110, the actuator 130 based on the control variable (y) to obtain the output torque (o) and thereby control drivability of the hybrid vehicle.
Step 308 is performed before the control variable (y) is calculated. Step 308 includes back-calculating the time constant 124 based on at least the proportional gain 126 and the reference torque (r) such that the output torque (o) yields the same value as in the previous calculation step. The back-calculation/re-calculation is performed when either one of the proportional gain 126 and the reference torque (r) is changed. The method uses the proportional gain 126 and the time constant 124 to determine the transfer function behavior of the controller 110.
The proportional module 112 is adapted to handle the proportional gain 126 and the integral module 114 is adapted to handle the time constant 124. The integration module 114 is a low pass filter. Further, the actuator 130 is at least one selected from the group consisting of: fuel injectors, spark plugs, throttle actuators, EGR valves, and VVTs.
Fig. 4 illustrates a detailed method of controlling drivability of a vehicle according to an embodiment of the present invention. Step 402 includes detecting a change in driver demand (d) at an input of the controller 110. Step 404 is only implemented if there is a change. Step 404 includes detecting a change in the reference torque (r). If the reference torque (r) is unchanged, step 406 is performed, otherwise step 408 is performed. Step 406 includes detecting whether there is a change in the proportional gain 126 and the time constant 124. Step 410 is only implemented if there is a change, otherwise step 440 is implemented. Step 410 includes performing a back calculation taking into account the changes in the control parameters (i.e., proportional gain 126 and time constant 124), followed by step 440 which includes calculating the control variable (y).
Step 408 includes detecting changes in the proportional gain 126 and the time constant 124. If a change is detected, step 430 is implemented, otherwise step 420 is implemented. Step 420 includes a step 440 of performing a back calculation taking into account the variation of the reference torque (r), followed by a calculation including the control variable (y).
Step 430 includes performing a back-calculation taking into account the reference torque (r) and the changed control parameters (i.e., proportional gain 126 and time constant 124), and then performing step 440 of calculating the control variable (y).
In another approach, the back-calculation of the state variables is always performed regardless of whether a change is detected in the reference torque (r), the proportional gain 126, and the time constant 124.
Fig. 5 shows different scenarios of drivability control according to an embodiment of the invention. Two rows within the first set of rows 502 represent various states of the reference torque (r) and the proportional gain 126. The three rows in the second set of rows 504 represent the states of the time constant 124, the control variable (y), and the output torque (o) on the hybrid vehicle without using the present invention or without the controller 110 and the method. The three rows in the third set of rows 506 represent the states of the time constant 124, the control variable (y), and the output torque (o) when the present invention or controller 110 and the method are used. Thus, fig. 5 depicts the working principle of the present invention and provides a comparative study without using the present invention.
Considering the states under two columns of the first column set 512, in the first row set 502, the reference torque (r) does not change, while the proportional gain 126 changes (decreases) from high to low and changes (increases) from low to high. According to the second set of rows 504, the time constant 124 does not change, while the control variable (y) has the same effect as the proportional gain 126, and so does the output torque (o). Here, the output torque (o) must not change. However, with the present invention, the time constant 124 changes inversely with the change in the proportional gain 126 according to the third set of rows 506. Thereby, it is ensured that the control variable (y) and, thus, the output torque (o) are not changed. The purpose of eliminating jump is realized.
Considering the states under two columns of the second column set 514, in the first row set 502, the reference torque (r) changes (i.e., increases or decreases), and the proportional gain 126 remains unchanged. According to the second set of rows 504, the time constant 124 and the control variable (y) are not changed, while the output torque (o) has the same effect as the reference torque (r). Here, the variation of the output torque (o) is also not expected. However, in the case of using the present invention, according to the third set of rows 506, the time constant 124 is changed inversely to the state of the reference torque (r), and so is the control variable (y). This ensures that the output torque (o) does not change, thereby providing a jerk-free drivability output or experience.
Considering the states in both columns of the third column set 516, in the first row set 502, both the reference torque (r) and the proportional gain 126 change (i.e., increase or decrease). Without the present invention, in the second set of rows 504, the time constant 124 does not change, but the control variable (y) and the output torque (o) have the same effect as the corresponding reference torque (r). Specifically, the output torque (o) undergoes a disproportionately large change, which is completely undesirable. However, in the case where the present invention is used, in the third set 506, the time constant 124 is changed inversely to the state of the reference torque (r), and so is the control variable (y). Here, the time constant 124 undergoes a disproportionately large change. This ensures that the output torque (o) does not change, thereby providing a jerk-free output.
According to the present invention, a method for filtering driver demand only in a hybrid vehicle is provided. The responses obtained by implementing the method are shown and explained in fig. 6 and 7.
Fig. 6 illustrates the operation of the present invention by waveforms according to an embodiment of the present invention. A first graph 610 and a second graph 620 are shown. In both graphs, the X-axis 602 represents time in suitable units (e.g., milliseconds (ms)), and the Y-axis 604 represents torque in suitable units (e.g., newton meters (Nm)). For clarity of understanding, the second graph 620 must be interpreted consistently with the first graph 610. T of both the first graph 610 and the second graph 6201To t6Are consistent. Point t of the first plot 6101To t6And point t of the second graph 6201To t6Co-linear.
In the first graph 610, a first curve 606 in solid lines represents driver demand (d). A second curve 608 in a dashed line represents the torque output, i.e., the reference torque (r) of the auxiliary engine 102. A third curve 612 in dashed lines represents the state of engine demand (x). As represented by the first curve 606, the driver demand (d) is at time t2Rises and at time t5And drops. At time t2Before and at time t5Thereafter, the driver demand (d) is zero. In other words, the driver demand (d) is at time t2Is preceded by zero and at time t2And t5With a nonzero gap therebetween. During the same time, the reference torque (r) of the auxiliary engine 102 is at time t1Is increased at t3Is decreased and then at t4Previously held at zero, subsequently reduced to negative torque, and then at t6And increases back to zero. Similarly, the engine demand (x) of the IC engine 106 begins at zero, but at t1And the battery is charged when the auxiliary engine 102 is supplying the necessary torque. The engine demand (x) is then at t2To a point where the combined output torque of the IC engine 106 and the auxiliary engine 102 matches the driver demand (d). Engine demand (x) at t3Further increased to compensate for the drop in reference torque (r) by assisting the engine 102. When the auxiliary engine 102 is driven as a generator and acting as a load, the engine demand (x) is at t4And (c) is further increased. At t5Here, the engine demand (x) from the IC engine 106 is reduced to a value for operating only the assist engine 102 due to the reduction of the driver demand (d), and is reduced to zero later when the assist engine 102 is stopped.
In the second graph 620, the driver demand is not shown for simplicity. The second graph 620 represents the engine demand (x) requested of the IC engine 106 after filtering is completed by the controller 110. A fourth curve 614 represents engine demand (x) without the use of controller 110. A fifth curve 616 represents the engine demand (x) with the controller 110 in use. The fourth curve 614, when viewed in conjunction with the third curve 612, indicates filtering at each change in engine demand (x), regardless of whether there is driver demand (d), i.e., at t1And t2In between, at t2And t3In between, at t3And t4In between, at t4And t5In between, at t5And t6And so on. This results in a jump or a jerk in the drivability of the hybrid vehicle. However, when looking at the fifth curve 616 in conjunction with the third curve 612, the controller 110 filters the engine demand (x) only during those time intervals when there is a change in driver demand, i.e., at t2And t3At t5And t6In the meantime. The controller 110 ensures that filtering is removed in undesirable time intervals and provides a smooth drivability experience to the driver.
FIG. 7 illustrates an analysis of drivability with and without a controller by a waveform according to an embodiment of the invention. The third graph 710 represents an expected or desired drivability response of the hybrid vehicle. The fourth graph 720 represents drivability response of the hybrid vehicle with and without the controller 110. The X-axis 602 represents time in suitable units and the Y-axis 604 represents torque in suitable units.
In the third graph 710, the first curve 606 is the same as explained in fig. 6. The first curve 606 is further marked with a circle. The sixth curve 702 represents the expected drivability response for the driver demand (d). The sixth curve 702 is marked with a cross to clearly distinguish it from the first curve 606. In the fourth graph 720, the first graph 606 is omitted for simplicity. A seventh curve 704 represents the drivability response without the controller 110. A total of four different peaks are seen, which results in providing a jump or jerk to the hybrid vehicle. However, a response similar to the expected response of the sixth curve 702 is seen when using the controller 110. An eighth curve 706 depicts the engine demand (x) requested from the IC engine 106. The eighth curve 706 is shown in light color and with cross markings, while the seventh curve 704 is shown in dark color and with triangular markings to clearly distinguish the two curves.
According to the present invention, the control performance of the IC engine 106 employed in the hybrid vehicle is improved by the back calculation according to the reference torque (r), the proportional gain 126, and the time constant 124. In particular, continuous behavior of the control variable (y) can be achieved despite step changes in various parameters of the controller 110 (e.g., the proportional gain 126 and the time constant 124). In addition, the step behavior of the control variable (y) may be achieved while various parameters (e.g., proportional gain 126) remain unchanged. The present invention considers a change in any of the proportional gain 126, the reference torque (r), and the engine demand (x) as a changed boundary condition imposed on the previously calculated control variable (y). For these calculations, the appropriate inverse transfer function is used. The transfer function determines a previously calculated control variable (y) from the control parameter and manipulates the control variable (y). Thus, it is ensured that the subsequent calculation of the control variable (y) is adjusted to the desired behavior. The present invention allows the overall output response of the system to remain the same despite variations in the reference torque (r) and control parameters (i.e., proportional gain 126 and time constant 124).
According to an embodiment of the present invention, the controller 110 provides torque coordination in a hybrid vehicle. The torque changes from an internal torque level to a clutch or even wheel torque level. Enabling the controller 110 to take into account sudden torque changes in surge damping. Sudden torque changes may come not only from the electric motor, but also from electrical accessories such as Air Conditioners (AC), heaters, infotainment systems, wipers, etc. Other/similar possibilities exist, such as intermediate change from driver torque demand to electrical energy as the main parameter, but finally the demanded torque at the wheels has to be delivered by a plurality of engines. The controller 110 ensures coordination of energy delivery and consumption by the different engines/energy sources in the vehicle (e.g., during battery loading/recovery) as follows: the torque delivered at the wheels corresponds to the driver's demand, regardless of the additional power consumption and the amount of transmission. The present invention provides a complete solution.
It should be understood that the embodiments explained in the above description are only illustrative and do not limit the scope of the present invention. Many other modifications and variations of such embodiments, as well as those explained in the specification, are contemplated. The scope of the invention is limited only by the scope of the claims.
