阅读说明：本技术 用于发动机控制器和队列行驶控制器的接口 (Interface for engine controller and queue run controller ) 是由 V·A·苏简 C·L·希尔默 E·C·塞弗 H·R·弗罗斯特 于 2018-12-14 设计创作，主要内容包括：一种用于车辆的控制系统包括发动机控制器,所述发动机控制器可操作以响应于巡航控制设置命令和巡航控制偏移值而确定请求的发动机扭矩,响应于所述请求的发动机扭矩和扭矩极限而确定发动机扭矩命令,并且响应于所述发动机扭矩命令而控制发动机的操作。所述控制系统还包括队列行驶控制器,所述队列行驶控制器可操作以确定并向所述发动机控制器提供所述巡航控制设置命令、所述巡航控制偏移值和所述扭矩极限以有效地使所述发动机控制器控制所述发动机以提供所述车辆与第二车辆之间的期望跟随距离。(A control system for a vehicle includes an engine controller operable to determine a requested engine torque in response to a cruise control set command and a cruise control offset value, determine an engine torque command in response to the requested engine torque and a torque limit, and control operation of an engine in response to the engine torque command. The control system further includes a fleet travel controller operable to determine and provide the cruise control set command, the cruise control offset value, and the torque limit to the engine controller effective to cause the engine controller to control the engine to provide a desired following distance between the vehicle and a second vehicle.)

1. A control system for a vehicle, comprising:

an engine controller operable to determine a requested engine torque in response to a cruise control set command and a cruise control offset value, determine an engine torque command in response to the requested engine torque and a torque limit, and control operation of an engine in response to the engine torque command; and

an autonomous controller operable to determine and provide the cruise control set command, the cruise control offset value, and the torque limit to the engine controller effective to cause the engine controller to control the engine to provide a target operating parameter for the vehicle.

2. The control system of claim 1, wherein the autonomous controller is a platoon travel controller, and the platoon travel controller is configured to determine the cruise control set command, the cruise control offset value, and the torque limit in response to a difference between a target following distance and an actual following distance of the vehicle from a second vehicle.

3. The control system of claim 1, wherein the autonomous controller is a platooning controller and the platooning controller includes a platooning distance control component configured to determine an acceleration response based on a difference between a target following distance of the vehicle and an actual following distance of the vehicle.

4. The control system of claim 3, wherein the in-line ride controller includes an acceleration control component that determines wheel torque in response to the acceleration response.

5. The control system of claim 4, wherein the in-line cruise controller includes a powertrain command control component configured to determine the cruise control set command, the cruise control offset value, and the torque limit in response to the wheel torque.

6. The control system of claim 4, wherein the powertrain command control component is further configured to determine a braking torque.

7. The control system of claim 1, wherein the autonomous controller is operable to provide the cruise control setting command and the cruise control offset value to the engine controller via one or more messages broadcast over a controller area network.

8. The control system of claim 1, wherein the autonomous controller is operable to provide the cruise control set command and the cruise control offset value to the engine controller via one or more extended cruise control/vehicle speed (CCVS2) messages, the extended CCVS2 messages including a cruise control set command parameter and a cruise control offset parameter.

9. The control system of claim 1, wherein the autonomous controller is operable to provide the torque limit to the engine controller via one or more messages broadcast over a controller area network.

10. The control system of claim 1 wherein the autonomous controller is operable to provide the torque limit to the engine controller via one or more torque/speed control (TSC1) messages.

11. The control system of claim 1 wherein the engine controller is operable to broadcast the requested engine torque over a controller area network to control transmission gear selection in response to the broadcast requested engine torque.

12. A method for operating a vehicle, comprising:

determining, with an autonomous controller, a cruise control set command, a cruise control offset value, and a torque limit for the vehicle effective to provide a target operating parameter;

determining a requested engine torque with an engine controller of the vehicle in response to the cruise control set command and the cruise control offset value from the autonomous controller;

determining, with the engine controller, an engine torque command in response to the requested engine torque and the torque limit from the autonomous controller; and

controlling operation of an engine of the vehicle in response to the engine torque command.

13. The method of claim 12, wherein the target operating parameter is a target following distance of the vehicle from a second vehicle, and further comprising determining, with the autonomous controller, an acceleration response based on a difference between the target following distance of the vehicle and an actual following distance of the vehicle.

14. The method of claim 13, further comprising determining, with the autonomous controller, a wheel torque based on the acceleration response.

15. The method of claim 14, wherein the autonomous controller includes a driveline command control component configured to determine the cruise control setting command, the cruise control offset value, and the torque limit in response to the wheel torque.

16. The method of claim 15, wherein the driveline command control component further determines a braking torque in response to the wheel torque.

17. The method of claim 12, further comprising broadcasting the cruise control set command, the cruise control offset value, and the torque limit from the autonomous controller to the engine controller over a controller area network.

18. A method for operating a vehicle in a fleet, comprising:

receiving a fleet engagement command at a fleet travel controller of the vehicle;

transmitting a cruise control set speed, a cruise control offset, and a torque limit from the fleet travel controller to an engine controller of the vehicle to maintain the vehicle at a target distance from a second vehicle;

determining a cruise control governor target torque with the engine controller in response to the cruise control set speed and the cruise control offset;

limiting an engine torque command from the engine controller in response to the cruise control target torque and the torque limit; and

operating the engine in response to the engine torque command.

19. The method as recited in claim 18, wherein said in-line cruise controller transmits said cruise control set speed and said cruise control offset to said engine controller via one or more extended cruise control/vehicle speed (CCVS2) messages.

20. The method of claim 18 wherein the platooning controller transmits the torque limit to the engine controller using one or more torque/speed control (TSC1) messages.

Background

The present application relates to interfaces for engine controllers and autonomous controllers. Vehicle fleet operation provides the potential for reduced fuel consumption and improved fuel economy through coordinated operation of a group of vehicles traveling along a route. For example, controlling the operation of the following vehicle to maintain a specified following distance from the lead vehicle may reduce aerodynamic losses experienced by the following vehicle. To provide such operation, the controller may be operated to provide a torque command to the engine to achieve the specified following distance. The commands provided by the controller may override or override other commands used by the engine controller. However, the interface between the autonomous controller and the engine controller may have a number of unexpected undesirable consequences, including effects that affect communication between the engine controller and the transmission controller or effects that affect transmission shifting. There remains a substantial unmet need for the unique apparatus, methods, and systems disclosed herein.

Disclosure of illustrative embodiments

For the purposes of clearly, concisely and accurately describing illustrative embodiments of the present disclosure, the manner and process of making and using the same, and to enable the practice, manufacture and use of the same, reference will now be made to certain exemplary embodiments, including those illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, and such alterations, modifications, and further applications of the exemplary embodiments as would occur to one skilled in the art are contemplated and protected by the present invention.

Disclosure of Invention

Exemplary embodiments include unique interfaces for engine controllers and autonomous controllers, and unique devices, methods, and systems that include or utilize such interfaces. Other embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Drawings

FIG. 1 is a schematic diagram illustrating certain aspects of an exemplary vehicle fleet.

FIG. 2 is a schematic illustrating certain aspects of an exemplary engine controller.

FIG. 3 is a schematic diagram illustrating certain aspects of an exemplary autonomous controller, such as a platoon travel controller.

FIG. 4 is a flow diagram illustrating certain aspects of an exemplary driver routine.

FIG. 5 is a flow diagram illustrating certain aspects of an exemplary fleet vehicle controller program.

FIG. 6 is a flow chart illustrating certain aspects of an exemplary engine controller routine.

Fig. 7 is a table illustrating certain aspects of an exemplary extended CCVS2 message.

Detailed Description

Referring to fig. 1, certain aspects are shown illustrating an exemplary system for a vehicle train 100 including a plurality of vehicles 102a, 102b, etc. (collectively and individually referred to herein as one or more vehicles 102). The vehicles 102 in the vehicle fleet 100 are operable to function in a coordinated manner to reduce net fuel consumption and increase net operating efficiency relative to uncoordinated operation. The illustrated vehicle train 100 includes two train-running trucks operating under highway over-the-road conditions. The front truck (vehicle 102a) is under driver torque control (e.g., via a direct throttle pedal or cruise control). The rear truck (vehicle 102b) maintains a following distance D from the front truck using a platoon ride controller 114 structured to interface with an engine controller 112 in the vehicle electronic control system 110 via a controller area network 118.

Although two vehicles are shown in vehicle train 100 of FIG. 1, it should be appreciated that vehicle train 100 may include any number of two or more vehicles 102 controlled or operated in a coordinated manner. The vehicle 102 shown in fig. 1 is a tractor-trailer vehicle, however, the vehicles in the vehicle train may be of various types of vehicles, such as trucks, tractor-trailers, vans, buses, and passenger cars, among others. Some embodiments may contemplate that, for example, in the case of a commonly managed fleet of vehicles, the vehicles 102 in the vehicle fleet 100 may each be the same or similar type of vehicle. Some embodiments contemplate that vehicles 102 in vehicle fleet 100 may include different types or categories of vehicles, such as semi-tractor trailers and passenger cars.

Each of the vehicles 102a, 120b in the vehicle fleet 100 includes an engine 104a, 104b, respectively, such as an internal combustion engine or a hybrid engine-electric system or any suitable prime mover, structured to output power to propel the respective vehicle 102a, 102 b. Some embodiments may contemplate that the engines 104, 104b may each be the same or similar type of prime mover, such as in the case of a commonly managed fleet of vehicles. Some embodiments contemplate that the engines 104a, 104b may include different types or classes of prime movers, such as prime movers having different sizes, powers, or types (e.g., diesel engine powertrains, gasoline engine powertrains, natural gas powertrains, hybrid-electric powertrains, and electric powertrains). For ease of description, the engines 104a, 104b (collectively and individually referred to as engine prime movers 104) of the vehicle 102 can be any suitable prime mover, and use of the term "engine" is not limited to internal combustion engines, and it should be understood that these references also apply to and include other types of prime movers.

The vehicles 102a, 102b in the vehicle train 100 may utilize one or more environmental sensors or sensor systems 106a, 106b (collectively and individually referred to as sensor systems 106) to determine their positioning relative to other vehicles 102 in the vehicle train 100. Examples of the types of sensor systems 106 that may be utilized include radar systems, lidar systems, proximity sensor systems, and combinations of these and/or other sensor systems. The vehicles 102 in the vehicle fleet 100 also include a wireless communication system or link 108 that allows vehicle-to-vehicle (V2V) communication or vehicle-to-X (V2X) communication, where X represents various possible types of external networks.

The vehicles 102 in the vehicle fleet 100 may each include a Vehicle Electronic Control System (VECS)110 structured to control and monitor operation of the respective vehicle 102, as well as participate in homogeneous mode coordination operations as disclosed herein. The VECS 110 typically includes a plurality of integrated circuit-based Electronic Control Units (ECUs) or other control components that may be operatively coupled to one another via a communication bus or network, such as a Controller Area Network (CAN)118, and structured to implement a number of different controls.

For example, the illustrated VECS 110 includes an engine controller 112, a fleet controller 114, and may also include one or more other controllers, systems, or components 116, such as sensors and actuators, operatively coupled to a CAN 118. In the following discussion, fleet vehicle controller 114 is used, but it should be understood that fleet vehicle controller 114 may be any autonomous controller. These controllers may be implemented in one or more ECUs. For example, certain embodiments include an engine ECU structured to implement engine controller 112 to control and monitor operation of the engine and engine accessories as described herein, a fleet travel ECU structured to implement fleet travel controller 114 to control and monitor fleet travel operation as described herein, a transmission ECU (not shown) structured to control and monitor operation of a transmission (not shown), a wireless communication ECU structured to control vehicle wireless communication system 108, and one or more environmental sensor ECUs structured to control operation of environmental sensor system 106 may be provided.

In certain embodiments, two or more of these controllers may be implemented in a common ECU. It should also be appreciated that the control logic and control routines disclosed herein may be executed by a controller or control that is implemented in a dedicated control component of VECS 110 (e.g., in a dedicated ECU or other dedicated control circuit) or may be implemented across dedicated control components of VECS 110 in a distributed manner (e.g., through coordinated operation of an engine ECU, a transmission ECU, a wireless communication ECU, and an environmental sensor ECU).

The controller, ECU, and other control components of VECS 110 may include digital circuitry, analog circuitry, or a hybrid combination of the two types. The ECU and other control components of VECS 110 may be programmable, integrated state machines, or a hybrid combination thereof. The ECU and other control components of VECS 110 may include one or more Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), memory, limiters, regulators, filters, format converters, and the like, which are not shown for clarity. In one form, the vehicle electronic control system 110 is a programmable variety that executes algorithms and processes data according to operating logic defined by executable program instructions stored in a non-transitory memory medium (e.g., software or firmware). Alternatively or additionally, the operating logic for the vehicle electronic control system 110 may be defined, at least in part, by hardwired logic or other hardware.

The environmental sensors and wireless communication capabilities of the vehicle 102 allow for coordination of its operation using direct and/or indirect communication. Such operation may be referred to as coordinated operation or homogeneous mode operation. For example, the vehicles 102 may accelerate or brake simultaneously or through a coordinated sequence, maintain a certain distance relative to each other, or maintain a certain offset relative to each other. The coordinated operation also allows closer following distances between vehicles by compensating for or eliminating the reaction distances required for human reactions. Coordinated operation of the vehicle fleet 100 also allows for operations to reduce the net consumption of vehicle fuel or increase the net efficiency of the vehicle fleet 100. In some embodiments, one or more of the vehicles 102 may be equipped with aerodynamic capabilities (wind deflectors on cabs and trailers, aerodynamic tractor bodies) that produce laminar air flow (tunneling) that greatly reduces air resistance. Other vehicles 102 in the fleet 100 may be spaced sufficiently close to the vehicle 102 using a wind break tunnel (wind break tunnel) to improve fuel economy. It should be appreciated that the controls disclosed herein may mitigate aerodynamic losses by adjusting one or more of vehicle following distance and vehicle offset.

Referring to FIG. 2, a schematic diagram illustrating certain aspects of the exemplary engine controller 112 is shown. Engine controller 112 implements a plurality of torque request control components, including driver input 130 and associated accelerator pedal 131, cruise control input 132, and PTO governor 134. Each of these control components is structured to provide a torque request in response to one or more respective inputs thereof for one or more torque/speed control (TSC1) messages 151 having one or more control destinations P1, P2, P3, P4,. PX. For example, control purpose P1 is for accelerator pedal/operator selection; the control purpose P2 is for cruise control; control purpose P3 is for the PTO governor; and control purpose P4 is for a road speed limiter.

The engine controller 112 also implements a number of torque constraints including a road governor 136 with control purpose P4 to control road speed, an idle governor 138, a full load governor 140 for smoke control, and an engine protection governor 142 with control purpose P5 for engine protection. The output signals of these torque request control components are connected in the manner shown to a plurality of operators including a minimum operator operable to output the minimum of a plurality of inputs, a maximum operator operable to output the maximum of a plurality of inputs, and mode control or override selection. The final output of the engine controller is the actual engine percent torque 144 achieved by the engine. In addition, four engine controller signals are transmitted to the CAN network 118: driver powertrain demand percentage torque 146, actual engine percentage torque 144, nominal friction percentage torque 148, and engine desired operating speed 150. These outputs to the CAN network 118 may be utilized by other controllers, such as a transmission controller (not shown).

It should be appreciated that the external torque command (represented in FIG. 2 as P32 and including, for example, traction and transmission control) may also effect control of the engine by the engine controller 112 via direct torque control signals such as torque/speed control (TSC1) control messages 152 provided as inputs to the control mode input operator 153 of the engine controller 112. The TSC1 control message 152 may be received from the fleet travel controller 114. The command from the control mode input operator 153 may affect the engine torque through four control modes: normal control mode, speed control mode, torque control mode and speed/torque limit control. Further, the above-described torque request control components 130, 132, 134 that drive the torque commands may be replaced by TSC1 control signals 152, which may be selected by a torque control mode input operator 153. There are exceptions to the substitution of torque control modes for the torque request control components 130, 132, 134, including HSI, LSI, torque curves, combustion and charge derates, and other higher priority TSC1 messages.

In the illustrated embodiment, the TSC1 control message 152 provided to the control mode input operator 153 as destination P32 is a torque limit value provided by the platooning controller 114. The platoon drive controller 114 also provides a cruise control set command (CC set) and a cruise control offset (CC offset) (collectively, [ CC set + CC offset ]154) as inputs to the cruise control torque request component 132. By selecting the values of [ CC set and CC offset ]154, the platooning controller 114 may affect the operation of the engine controller 112 to provide a torque request to the control mode input operator 153 that establishes and provides a torque corresponding to the maximum acceleration for use in maintaining or providing the desired following distance D. The torque limit in the TSC1 message 152 from the platooning controller 114 may be used to compensate or reduce this maximum value. The CC set + CC offset 154 and corresponding maximum acceleration available to the platooning controller 114 may be selected at any torque level up to the maximum torque level that the engine may provide.

In some forms, [ CC set + CC offset ]154 and the corresponding maximum acceleration available to the in-line cruise controller 114 may be selected to provide a desired acceleration capability and corresponding torque that is less than the maximum torque magnitude that the engine may provide. This provides effective or substantial full authority control of engine operation through the platooning controller 114 without requiring direct torque control commands specifying explicit overrides of all other torque requesting components.

Referring to FIG. 3, a schematic diagram illustrating certain aspects of an exemplary platoon drive controller 114 is shown. The platoon driving controller 114 is provided as a feedback controller, such as an operation to reduce the target distance (D)_Target) Actual distance (D) from being received as feedback_{Practice of}) The error therebetween to control the PID, PI or similar type of controller that the vehicle follows the distance D. However, as discussed above, platooning controller 114 may be any suitable autonomous controller and function to control any suitable operating parameter in addition to or in lieu of the desired following distance, including a desired vehicle acceleration, a desired vehicle speed, or other suitable operating parameter.

Queue distance (queue D) controller component 160 receives D_TargetAnd D_{Practice of}The difference 162 therebetween and determines an acceleration 164 that is provided to a queue acceleration control component 166. The fleet acceleration (dV/dt) control component 166 determines a target wheel torque 168 that is provided to a powertrain/chassis control component 170. Powertrain/chassis control component 170 determines a torque limit (τ)_{eng limit})172a, a cruise control set command (CC set) 172b, and a cruise control offset (CC offset) 172c, which are provided to the engine controller 112 to affect the engine speed as described aboveControl of the motive machine (or other prime mover). The powertrain/chassis control component 170 may also determine a brake torque limit (τ) that is provided to the brake controller 176_Brake)174. The outputs from the engine controller 112 and the brake controller 176 are used to determine vehicle dynamics 178. Radar 180 and vehicle dynamics for repeated determination of D_{Practice of}。

The torque limit 172a, the cruise control set command 172b, and the cruise control offset 172c may be transmitted via the CAN 118. The torque limit 172a may be transmitted as a TSC1 message. The cruise control set command 172b may be transmitted as a modified cruise control/vehicle speed (CCVS2) message or an engine-specific or platform-specific message, such as that shown in fig. 7. Cruise control offset 172c may also be transmitted as a modified CCVS2 message or an engine-specific or platform-specific message.

The platoon running controller 114 performs the following processes: (a) the engine CC set speed establishes the current vehicle speed as the CC set speed 172a, (b) the CC offset 172b informs the engine that a higher cruise control speed is desired, as indicated by CC set speed + CC offset 154, (c) the engine cruise control governor attempts to achieve CC set speed + CC offset 154 by increasing engine output torque, (d) however, the platooning controller 114 limits engine output torque by torque limit 172a, thereby preventing the vehicle 102 from achieving CC set speed + CC offset 154, (e) the engine cruise control governor continues to attempt to achieve CC set speed + CC offset 154 and ultimately the maximum torque demand to the torque limit curve, and (f) control based on the torque limit has substantial or effective full authority over the torque output of the engine or other prime mover as long as the actual speed < [ CC set speed + CC offset ] 154.

Referring to FIG. 4, a flow diagram 400 illustrating certain aspects of an exemplary driver routine is shown. The illustrated flow chart generally represents operations performed by a driver of the vehicle 102 during a queue travel operation according to the present disclosure. The operations of fig. 4 may occur concurrently with the operations of one or both of fig. 5 and 6. Other aspects of the operations and conditions associated with the elements of fig. 4 include the driver engaging a platoon travel button or input in the vehicle 102 to operate in the platoon 100 at block 402 and disengaging the platoon travel button or input to operate outside the platoon 100 at block 404.

Referring to FIG. 5, a flow diagram illustrating certain aspects of an exemplary fleet vehicle controller program 500 is shown. The illustrated flow chart generally represents operations performed by fleet travel controller 114 during fleet travel operations in accordance with the present disclosure. The operations of fig. 5 may occur concurrently with the operations of one or both of fig. 4 and 6.

Other aspects of the operations and conditions associated with the elements of fig. 5 include: operation block 502, where the fleet engagement controller 114 receives a fleet engagement command; operation block 504, in which the CCVS2 enable command and the CC set command 172b are sent to the Engine Controller (ECM) 112; operation block 506, where the cruise control offset command 172c is sent from the in-line cruise controller 114 to the engine controller 112; and operation block 508, where the platooning controller 114 limits the engine output torque to achieve the desired trailing vehicle acceleration to maintain the separation distance D in response to the torque limit 172a in the TSC1 message 152.

Routine 500 continues at conditional block 510 to check to determine if the full torque authority is available for use by the torque limit signal. If the actual vehicle speed is close to the actual speed of [ CC set speed + CC offset ]154, the full torque authority may not be obtained. If condition block 510 is true, then the process 500 returns to operation block 508. If condition block 510 is false, routine 500 continues at operation block 512, where if full authority is not available, the CCVS2 set command is re-sent to the engine controller 112 to increase the CC set speed to the current vehicle speed and the cruise control offset command is re-sent to the engine controller 112. Routine 500 checks at conditional block 514 whether an out of queue command is received by in-queue run controller 114. If condition block 514 is true, routine 500 continues at operation block 516, where CCVS2 cancels the command sent from queued travel controller 114 to engine controller 112 and queued travel stops. If conditional block 514 is false, then program 500 returns to operation block 508.

Referring to FIG. 6, a flow chart illustrating certain aspects of an exemplary engine controller routine 600 is shown. The illustrated flow chart generally represents operations performed by the engine controller 112 during a platoon travel operation in accordance with the present disclosure. The operations of fig. 6 may occur concurrently with the operations of one or both of fig. 4 and 5.

Other aspects of the operations and conditions associated with the elements of fig. 6 include operation block 602 for the engine controller 112 receiving a CCVS2 enable and set command. The routine 600 continues at operation block 604, where the current vehicle speed becomes the CC set speed for the engine cruise control governor 132. The routine 600 continues at operation block 606, where the engine controller 112 receives a CC offset command. At operation block 608, [ CC set speed + CC offset ]154 becomes the cruise control governor target.

The routine 600 continues at operation block 610, where the engine cruise control governor 132 increases torque in an effort to achieve [ CC set speed + CC offset ] 154. Routine 600 continues at operation block 612 to receive TSC1 torque limit command 152 and then outputs the lower of the CC governor torque and TSC1 torque limits at operation block 614. At conditional block 616, program 600 checks whether a CCVS2 cancellation is received. If conditional block 616 is false, then procedure 600 returns to operation block 602. If conditional block 616 is true, then procedure 600 ends.

Referring to FIG. 7, a table 700 illustrating certain aspects of an exemplary extended CCVS2 message structure for parameter sets such as CCVS2, Accelerator (ACC), and engine is shown. The parameter set is associated with various specific parameters including a cruise control disable command, a cruise control resume command, a cruise control suspend command, and a cruise control set command. The particular parameters may be communicated using any suitable vehicle communication structure, such as those indicated in table 700.

In some forms, the CCVS2 message may also include a CC offset value. In some forms, one or both of the CC set command and the CC offset value may be transmitted or broadcast over a Controller Area Network (CAN) using a standby message format or signal. The modified CCVS2 message is designed to allow a logic-based decision to enable cruise control. The modified CCVS2 messages include enable, set, restore, and cancel commands that allow third party or front engine controller devices to control the cruise system through data link messaging. This alleviates any need for the operator to set the cruise control using the instrument panel switches. This would also eliminate the need to provide a backup signal to the ECM directly or via an emulated datalink message.

In one embodiment, the vehicle cruise speed is the current vehicle speed once a modified CCSV2 message is issued for a following vehicle in the fleet (e.g., driving into a hill or during highway operation). Then another message, which may be similar to a Predictive Cruise Control (PCC) message, that allows different cruise control operations to be performed, providing an offset from the current set point speed that is high enough that the torque demand will attempt to increase the vehicle speed. The offset information message may alternatively be incorporated into the CCVS2 message. At this point, the platooning controller 114 may issue a torque limit command based on the feedback to turn down the torque as needed to maintain the desired spacing D. The cruise governor torque will tend to be at a peak torque level as long as the target cruise speed is sufficiently greater than that required to maintain the separation distance D. Thus, by torque limit control, ideally, the torque output can be controlled over its entire range and continuously.

If the target cruise speed CC set point + CC offset 154 is no longer sufficiently greater than the speed required to maintain the separation distance D (e.g., the lead truck may have increased its speed), a new modified CCVS2 message may be issued followed by a CC offset message. This would actually increase the set point to the current speed and provide an additional incremental offset. This may be done as many times as necessary so that the CC set value + CC offset 154 is sufficiently greater than the speed required to maintain the pitch. It should be appreciated that once the CCSV2 message is issued, the engine will operate the vehicle in a cruise control governor state. This will provide an explicit "driver torque request" over the data link to other devices such as the transmission. This driver torque request may then be used to help guide the shift schedule.

Various aspects of the present disclosure are contemplated. According to one aspect, a control system for a vehicle includes an engine controller operable to determine a requested engine torque in response to a cruise control set command and a cruise control offset value, determine an engine torque command in response to the requested engine torque and a torque limit, and control operation of an engine in response to the engine torque command. The control system also includes an autonomous controller operable to determine and provide the cruise control set command, the cruise control offset value, and the torque limit to the engine controller effective to cause the engine controller to control the engine to provide a target operating parameter for the vehicle.

In one embodiment, the autonomous controller is a platoon travel controller configured to determine the cruise control set command, the cruise control offset value, and the torque limit in response to a difference between a target following distance and an actual following distance from a second vehicle.

In another embodiment, the autonomous controller is a platoon travel controller comprising a platoon distance control component configured to determine an acceleration response based on a difference between a target following distance of the vehicle and an actual following distance of the vehicle. In a refinement of this embodiment, the in-line travel controller includes an acceleration control component that determines wheel torque in response to the acceleration response. In another refinement, the platoon driving controller includes a powertrain command control component configured to determine the cruise control set command, the cruise control offset value, and the torque limit in response to the wheel torque. In another refinement, the powertrain command control component is further configured to determine a braking torque.

In another embodiment, the autonomous controller is operable to provide the cruise control set command and the cruise control offset value to the engine controller via one or more messages broadcast over a controller area network. In yet another embodiment, the autonomous controller is operable to provide the cruise control set command and the cruise control offset value to the engine controller via one or more extended CCVS2 messages, the extended CCVS2 messages including a cruise control set command parameter and a cruise control offset parameter.

In another embodiment, the autonomous controller is operable to provide the torque limit to the engine controller via one or more messages broadcast over a controller area network. In another embodiment, the autonomous controller is operable to provide the torque limit to the engine controller via one or more TSC1 messages. In yet another embodiment, the engine controller is operable to broadcast the requested engine torque over a controller area network to control transmission gear selection in response to the broadcast requested engine torque.

In another aspect, a method for operating a vehicle includes: determining, with an autonomous controller, a cruise control set command, a cruise control offset value, and a torque limit for the vehicle effective to provide a target operating parameter for the vehicle; determining a requested engine torque with an engine controller of the vehicle in response to the cruise control set command and the cruise control offset value from the autonomous controller; determining, with the engine controller, an engine torque command in response to the requested engine torque and the torque limit from the autonomous controller; and controlling operation of an engine of the vehicle in response to the engine torque command.

In one embodiment, the method includes determining, with the autonomous controller, an acceleration response based on a difference between a target following distance of the vehicle and an actual following distance of the vehicle. In a refinement of this embodiment, the method includes determining, with the autonomous controller, a wheel torque based on the acceleration response. In another refinement of the method, the autonomous controller includes a driveline command control component configured to determine the cruise control set command, the cruise control offset value, and the torque limit in response to the wheel torque. In another refinement, the powertrain command control component further determines a braking torque in response to the wheel torque.

In another embodiment, the method includes broadcasting the cruise control set command, the cruise control offset value, and the torque limit from the autonomous controller to the engine controller over a controller area network.

According to another aspect, a method for operating vehicles in a fleet comprises: receiving a fleet engagement command at a fleet travel controller of the vehicle; transmitting a cruise control set speed, a cruise control offset, and a torque limit from the fleet travel controller to an engine controller of the vehicle to maintain the vehicle at a target distance from a second vehicle; determining a cruise control governor target torque with the engine controller in response to the cruise control set speed and the cruise control offset; limiting an engine torque command from the engine controller in response to the cruise control target torque and the torque limit; and operating the engine in response to the engine torque command.

In one embodiment, the platooning controller transmits the cruise control set speed and the cruise control offset to the engine controller via one or more CCVS2 messages. In another embodiment, the platooning controller transmits the torque limit to the engine controller using one or more TSC1 messages.

While illustrative embodiments of the disclosure have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the claimed invention are desired to be protected. It is to be understood that while the use of words such as preferred, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least a portion" are used, there is no intention to limit the claims to only one item unless specifically stated to the contrary in the claims. When the language "at least a portion" and/or "a portion" is used, the item can include a portion and/or the entire item unless specifically stated to the contrary.