Brake ECU, system, control method and vehicle

Abstract

To provide a brake ECU and the like which can unitarily manage requests from a plurality of application request parts achieving operation support function.SOLUTION: A brake ECU controlling a brake actuator of a vehicle comprises steps of: receiving a plurality of requests containing acceleration speed from an operation support system outside of the brake ECU; adjusting the plurality of requests containing the acceleration speed; calculating a request containing force based on the adjusting result; and distributing the request containing force into at least one of a plurality of actuator systems containing the brake actuator.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a brake ECU, a system, a control method, and a vehicle that controls the brakes of a vehicle. [Background technology]

[0002] Patent Document 1 describes a vehicle lateral movement control system that controls the lateral movement of a vehicle by driving actuators provided for front steering, rear steering, and braking, respectively. The system described in Patent Document 1 acquires availability that indicates the controllable range of each actuator, calculates an F / F requirement value for feedforward control of each actuator and an F / B requirement value for feedback control of each actuator using the acquired availability, and determines the mechanism to be controlled and the control amount to be ultimately generated for that mechanism based on the calculated F / F requirement value and F / B requirement value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-96619 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the number of driver assistance systems, such as those for autonomous driving and automatic parking, has been increasing. These systems make requests to the actuators that control the vehicle's drive, braking, and steering. As the number of types of driver assistance systems increases, the demands on each actuator also increase, making it difficult for the control unit (ECU) that controls each actuator to handle multiple requests.

[0005] Therefore, an object of the present invention is to provide a brake ECU or the like that can comprehensively manage requests from a plurality of application request units that realize driving assistance functions. [Means for solving the problem]

[0006] One embodiment of the present invention is a brake ECU that controls a brake actuator of a vehicle, and receives requests including multiple accelerations from a driving assistance system external to the brake ECU, arbitrates the requests including multiple accelerations, calculates a request including a force based on the arbitration result, and transmits the request including the force to an actuator system including the brake actuator. an actuator system including an actuator controlled by an ECU different from the brake ECU; At least one of a plurality of actuator systems including selectively Distribute. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a brake ECU or the like that can comprehensively manage requests from a plurality of application request units that realize driving assistance functions. [Brief explanation of the drawings]

[0008] [Figure 1] A functional block diagram showing a vehicle control system according to an embodiment. [Figure 2] FIG. 1 is a block diagram showing a configuration of a brake control ECU according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment) In one embodiment of the present invention, a vehicle control device (brake control ECU) that controls the brakes is provided with a function for comprehensively managing requests from multiple application request units to multiple actuators and a function for providing feedback on vehicle behavior to the multiple application request units.When multiple application request units simultaneously issue requests to each actuator, the brake control ECU arbitrates the multiple requests, simplifying processing in the control units that control each actuator.

[0010] <Configuration> FIG. 1 is a functional block diagram showing a vehicle control system according to an embodiment, and FIG. 2 is a block diagram showing the configuration of a brake control ECU according to an embodiment.

[0011] The vehicle control system shown in FIG. 1 includes a plurality of application request units 1a to 1c, an accelerator 2, a brake 3, a steering 4, a request arbitration unit 5, request generation units 6a to 6c, a vehicle motion control unit 7, a powertrain control unit 8, a brake control unit 9, a steering control unit 10, and actuators 12a to 12d.

[0012] The application request units 1a to 1c are applications (sometimes called advanced safety applications) that realize driving assistance functions for a vehicle, such as autonomous driving, autonomous parking, adaptive cruise control, lane keep assist, and collision mitigation braking. Based on each driving assistance function, the application request units 1a to 1c output requests to the actuators 12a to 12d to control the vehicle's motion. The application request units 1a to 1c are typically implemented by an ECU executing the applications. Depending on the driving assistance function being used, multiple application request units 1a to 1c may execute the applications simultaneously. While FIG. 1 shows three application request units 1a to 1c for the sake of simplicity, the number of application request units that realize the driving assistance functions is not limited, and two or more or four or more application request units may be implemented in the vehicle. The application request units 1a to 1c output request signals for operating the actuators 12a to 12d to a request arbitration unit 5, which will be described later.

[0013] The accelerator 2, the brake 3, and the steering wheel 4 are each an input device operated by the driver to control the movement of the vehicle. A request input by the driver by operating the accelerator 2 (accelerator pedal) includes information specifying the magnitude of the propulsive force or braking force required by the driver, and is notified to the request generation unit 6a and the request arbitration unit 5. A request input by the driver by operating the brake 3 (brake pedal) includes information specifying the magnitude of the braking force required by the driver, and is notified to the request generation unit 6b and the request arbitration unit 5. A request input by the driver by operating the steering wheel 4 (steering wheel) includes information specifying the amount of lateral movement or turning of the vehicle required by the driver, and is notified to the request generation unit 6c and the request arbitration unit 5. The requests based on the operation of the accelerator 2, the brake 3, and the steering wheel 4 are notified to the request arbitration unit 5 so that the input requests can be notified to the application request units 1a to 1c via the request arbitration unit 5.

[0014] The request arbitration unit 5 receives request signals output from the plurality of application request units 1a to 1c, and arbitrates the received requests.

[0015] As shown in FIG. 2, the request arbitration unit 5 includes an arbitration unit 15, a feedback (FB) controller 16, and a command value distribution unit 17.

[0016] The arbitration unit 15 arbitrates requests from the application request units 1a to 1c to the actuators 12a to 12d. The arbitration unit 5 arbitrates between information representing the longitudinal motion of the vehicle contained in the request signals received from the application request units 1a to 1c and information representing the lateral motion of the vehicle contained in the received data set. The information representing the longitudinal motion of the vehicle instructed by the application request units 1a to 1c is, for example, acceleration, and the information representing the lateral motion of the vehicle is, for example, acceleration or steering angle. For example, The stop unit 15 performs arbitration by selecting one request signal from the multiple received request signals based on predetermined selection criteria, and by setting an allowable range of control based on the multiple received request signals.

[0017] The FB controller 16 measures the vehicle motion based on the output values ​​of chassis-related sensors 14 provided on the chassis. The chassis-related sensors 14 include multiple types of sensors that measure vehicle state variables and driver operation amounts of control units. Examples of sensors that measure vehicle state variables include wheel speed sensors provided on each wheel, acceleration sensors that measure the vehicle's longitudinal and / or lateral acceleration, and a yaw rate sensor that measures the vehicle's yaw rate. Examples of sensors that measure the driver operation amounts of control units include a steering angle sensor that detects the steering operation amount, a brake pedal sensor that detects the brake pedal depression amount, and an accelerator pedal sensor that detects the accelerator pedal depression amount. The FB controller 16 also acquires information indicating the control results and operating states of the actuators 12a to 12d, which are notified from the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 (described later). The FB controller 16 feeds back the acquired information to the application request units 1a to 1c and also outputs it to a command value distribution unit 17 (described later). The application request units 1a to 1c can monitor the execution status of the control processing for providing the driving assistance function and change or stop the control processing as necessary based on various information fed back from the FB controller 16. The various information output from the FB controller 16 to the command value distribution unit 17 is used when the command value distribution unit 17 generates command values ​​for the request generation units 6a to 6c (described later), and is used for feedback control of the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 to bring the vehicle motion closer to the target motion which is the result of arbitration by the arbitration unit 15.

[0018] The command value distributor 17 distributes command values ​​to control units that control the multiple actuators 12a to 12d based on the arbitration result by the arbitration unit 15. When distributing the command values, the command value distributor 17 references various information output from the FB controller 16 and generates command values ​​for each of the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 so that the vehicle motion approaches a target motion. The command value distributor 17 outputs the distributed command values ​​to request generators 6a to 6c, which will be described later. By distributing the command values ​​based on the output of the FB controller, the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 are feedback-controlled based on their respective control performance values.

[0019] The request generator 6a generates requests for the actuators 12a and 12b based on the command value output from the command value distributor 17, and outputs the generated requests to the powertrain control unit 8. Similarly, the request generators 6b and 6c generate requests for the actuators 12c and 12d, respectively, based on the command value output from the command value distributor 17, and output the generated requests to the brake control unit 9 and the steering control unit 10. The request generators 6a to 6c may simultaneously receive requests from the driver input by operating the accelerator 2, the brake 3, and the steering wheel 4, and one or more requests from the application request units 1a to 1c. For example, there may be a situation in which the driver operates the brake 3 to decelerate or stop the vehicle with the intention of avoiding danger during automatic driving or automatic parking, or a situation in which the driver operates the steering wheel 4 with the intention of avoiding danger during lane keep assist control, causing the vehicle to move laterally or turn. Therefore, when a request from the driver and one or more requests from the application request units 1a to 1c are input at the same time, the request generation units 6a to 6c select one of the requests based on a selection criterion prepared in advance. The request generation units 6a, 6b, and 6c issue driving instructions to the powertrain control unit 8, the brake control unit 9, and the steering control unit 10, respectively, based on the one request selected by arbitration. In addition, the request generation units 6a, 6b, and 6c select one of the requests based on a request from the driver and one or more requests from the application request units 1a to 1c. When one of the requests is selected, the request arbitration unit 5 is notified of the selection result.

[0020] The vehicle motion control unit 7 comprehensively controls the vehicle's driving stability by controlling the actuators 12a-12d via the powertrain control unit 8, the brake control unit 9, and the steering control unit 10. Examples of control performed by the vehicle motion control unit 7 include control to suppress tire spin and vehicle skidding by controlling the powertrain output and braking force, control to prevent tire lock during sudden braking, and control to detect emergency braking from the amount and speed of brake depression and generate strong braking force. The control performed by the vehicle motion control unit 7 to maintain driving stability must be performed immediately when the vehicle's driving stability is impaired, and is therefore executed independently of drive instructions from the driver and drive instructions from the application request units 1a-1c. When the vehicle motion control unit 7 issues a drive instruction to any of the powertrain control unit 8, the brake control unit 9, and the steering control unit 10, it notifies the request arbitration unit 5 of information regarding the control amount (availability) currently achievable by the actuators 12a-12d. This information regarding availability is notified to the application request units 1a to 1c from the request arbitration unit 5. While the vehicle motion control unit 7 is operating, there are cases where the actuators 12a to 12d are unable to realize the requests made by the application request units 1a to 1c. By the vehicle motion control unit 7 notifying the application request units 1a to 1c of the information regarding availability via the request arbitration unit 5, the application request units 1a to 1c can change or adjust the control processing that is being executed.

[0021] The powertrain control unit 8 generates a propulsive force or braking force requested by the demand generator 6a or the vehicle motion control unit 7 by controlling the operation of the actuators 12a and 12b that constitute the powertrain (sometimes called a drivetrain). The powertrain control unit 8 is realized by, for example, one or a combination of an engine control ECU, a hybrid control ECU, a transmission ECU, etc. For the sake of simplicity, FIG. 1 shows two actuators 12a and 12b as the control targets of the powertrain control unit 8. However, the number of actuators controlled by the powertrain control unit 8 may be one or three or more depending on the configuration of the vehicle's powertrain. Examples of the actuators 12a and 12b that constitute the powertrain include an engine, a drive motor, a clutch, a torque converter, a transmission, and a mechanism that distributes torque to the front and rear wheels in a four-wheel drive vehicle.

[0022] The brake control unit 9 controls the operation of the brake actuators provided on each wheel to generate the braking force requested by the request generation unit 6b or the vehicle motion control unit 7. The brake control unit 9 is directly connected to the chassis system sensors 14 via signal lines, and receives the output values ​​of the wheel speed sensors 13 for each wheel included in the chassis system sensors 14 via the signal lines.

[0023] The steering control unit 10 controls the rotational force of the motor of the electric power steering (EPS) to control the direction of the tires connected via a rack and pinion mechanism. The steering control unit 10 is realized by, for example, a power steering control ECU.

[0024] As described above, there are cases where a request from one of the request generators 6a to 6c and a request from the vehicle motion controller 7 are input to the powertrain controller 8, the brake controller 9, and the steering controller 10 at the same time. For example, if a wheel skid is detected while the powertrain controller 8 is generating a requested propulsive force based on the driver's operation of the accelerator 2, the vehicle motion controller 7 controls the braking force generated by the brake actuator of each wheel and the output of the engine or the drive motor in order to suppress the vehicle skid. In this case, in order to prioritize skid suppression by the vehicle motion controller 7, the powertrain controller 8, the brake controller 9, and the steering controller 10 do not receive the request from the vehicle motion controller 7. The actuators 12a to 12d are controlled with priority.

[0025] The powertrain control unit 8, the brake control unit 9, and the steering control unit 10 drive the actuators 12a to 12d based on requests from the request generation units 6a to 6c, respectively. The powertrain control unit 8, the brake control unit 9, and the steering control unit 10 acquire information about the operating states of the actuators 12a to 12d based on response signals from the actuators 12a to 12d or measurement values ​​from sensors. Examples of the information about the operating states of the actuators include information about the availability of the actuators (information about whether the actuators can respond as expected), information about monitored values ​​of actuator outputs such as the thrust, braking force, yaw rate, and steering angle achieved by the actuators, and information specific to the actuators, such as whether the temperature of the brake pads is transitioning toward overheating. The powertrain control unit 8, the brake control unit 9, and the steering control unit 10 notify the request arbitration unit 5 of the information about the monitored values ​​of the outputs of the actuators to be controlled and information specific to the actuators. Furthermore, when the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 detect that an actuator to be controlled has failed, they notify the request arbitration unit 5 of information indicating the availability of the actuator to be controlled. Information regarding the operating status of each of the actuators 12a to 12d is further notified from the request arbitration unit 5 to the application request units 1a to 1c. The application request units 1a to 1c can change or adjust the control process being executed based on the notified operating status of the actuators 12a to 12d.

[0026] 2, a brake control ECU 20, which is a control device for controlling the brakes, includes the request arbitration unit 5, request generation units 6a to 6c, and vehicle motion control unit 7 shown in FIG. 1, in addition to a brake control unit 9. The brake control ECU 20, application request units 1a to 1c, powertrain control unit 8, and steering control unit 10 can communicate with each other through inter-ECU communication.

[0027] <Effects, etc.> The configuration of the brake control ECU 20 according to this embodiment has the following advantages.

[0028] First, by including the request arbitration unit 5, the brake control ECU 20 can centrally manage requests from the multiple applications 1a to 1c and distribute control variables (command values) required to achieve the required vehicle motion to the powertrain control unit 8, the brake control unit 9, and the steering control unit 10. This configuration, which centrally manages requests from the multiple application request units 1a to 1c using the request arbitration unit 5, has the advantage that it is not necessary to change the control processing of the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 even when a new application request unit that realizes a new driving assistance function is added. The brake control ECU 20 is installed in any type of vehicle. Therefore, by implementing the request arbitration unit 5 and the request generation units 6a to 6c in the brake control ECU 20, it is possible to centrally manage requests from the multiple application request units 1a to 1c that realize the driving assistance function in any type of vehicle. When a request arbitration unit 5 and a request generation unit 6a to 6c are provided in an existing brake control ECU 20, the costs required for the ECU and communication system and the increase in the number of types of ECUs and communication systems can be reduced compared to when a new control device (ECU) that centrally manages requests from applications 1a to 1c is provided.

[0029] Regardless of the vehicle model, vehicles are equipped with an ECU that controls the powertrain (powertrain control unit 8) and an ECU that controls the steering (steering control unit 10). However, if communication between the ECUs is interrupted, the ECU that controls the steering cannot generate braking force by itself. Also, although the powertrain control ECU can generate braking force by pumping loss, it cannot use friction brakes, so it cannot generate braking force. Therefore, it is most preferable to provide the request arbitration unit 5 and the request generation units 6a to 6c in the brake control ECU 20 from the viewpoint of ensuring sufficient brake function remaining in the event of a failure.

[0030] Furthermore, if a failure occurs in a part of the composite control system, the control to be performed to ensure safety differs depending on the vehicle speed. For example, if the vehicle speed at the time of the failure is 3 km / h or less, it is preferable to immediately apply the brakes to stop the vehicle, whereas if the vehicle speed at the time of the failure is 50 km / h, it is necessary to gradually decelerate the vehicle before stopping it. Wheel speed sensors are essential for reliable detection of vehicle speed, and the measured values ​​of the wheel speed sensors are directly input to the brake control ECU 20 via signal lines. Therefore, from the perspective of performing control to transition to a safe state depending on the vehicle speed, it is desirable to provide the request arbitration unit 5 and the request generation units 6a to 6c in the brake control ECU 20.

[0031] The brake control ECU 20 according to this embodiment includes an FB controller 11 that measures actual vehicle control values ​​to be used for feedback control. Compared to a case where a controller that feeds back actual vehicle control values ​​for longitudinal (front-rear) motion and a controller that feeds back actual vehicle control values ​​for lateral (left-right) motion are provided for each control function of the driving assistance system, this has the advantage of minimizing the number of controllers. Furthermore, when the FB controller 11 is provided in the brake control ECU 20, the amount of communication required when feeding back actual vehicle control values ​​measured by the FB controller 11 to the application request units 1a to 1c can be reduced, thereby reducing the communication load.

[0032] Furthermore, the application request units 1a to 1c require information on the execution status of the requests issued to the actuators 12a to 12d and information on the health of the actuators 12a to 12d in order to continuously perform control processing for realizing the driving assistance function. The request arbitration unit 5 aggregates information on the operating states of the actuators 12a to 12d acquired by the powertrain control unit 8, the brake control unit 9, and the steering control unit 10 and notifies the information to the application request units 1a to 1c, thereby reducing the communication load required for notifying the information on the operating states of the actuators 12a to 12d.

[0033] Furthermore, when a vehicle motion control unit 7 that autonomously controls the motion stability of the vehicle is implemented in the vehicle as in this embodiment, it is preferable that the vehicle motion control unit 7 is also implemented in the brake control ECU 20. While the vehicle motion control unit 7 is executing control, it prioritizes the use of the actuators 12a to 12d, and therefore needs to notify the application request units 1a to 1c of information regarding the availability of the actuators 12a to 12d. In this embodiment, the vehicle motion control unit 7 can notify the request arbitration unit 5 provided in the same brake control ECU 20 of information with minimal delay. The request arbitration unit 5 can centrally manage the information to be notified to the application request units 1a to 1c. [Industrial Applicability]

[0034] The present invention can increase the utility value of a brake control device mounted on a vehicle. [Explanation of symbols]

[0035] 1a~1c Application request section 5 Request Mediation Department 6a~6c Request generator 8 Powertrain Control Unit 9 Brake control unit 10 Steering control unit 12a~12d Actuators 15 Mediation Department 16 Feedback (FB) Controller 17 Command value distribution section

Claims

1. A brake ECU that controls a brake actuator of a vehicle, a brake ECU that receives requests including a plurality of accelerations from a driving assistance system external to the brake ECU, arbitrates the requests including the plurality of accelerations, calculates a request including a force based on the arbitration result, and selectively distributes the request including the force to at least one of a plurality of actuator systems, including an actuator system including the brake actuator and an actuator system including an actuator controlled by an ECU different from the brake ECU.

2. A brake ECU that controls a brake actuator of a vehicle, A brake ECU that receives requests including a plurality of accelerations from a plurality of ADAS applications external to the brake ECU, arbitrates the requests including the accelerations, calculates a request including a force based on the arbitration result, and selectively distributes the request including the force to at least one of a plurality of actuator systems, including an actuator system including the brake actuator and an actuator system including an actuator controlled by an ECU different from the brake ECU.

3. A brake ECU that controls a brake actuator of a vehicle, a brake ECU that receives requests including a plurality of accelerations from a plurality of driving assistance applications external to the brake ECU, arbitrates the requests including the accelerations, calculates a request including a force based on the arbitration result, and selectively distributes the request including the force to at least one of a plurality of actuators, including the brake actuator and an actuator controlled by an ECU different from the brake ECU.

4. A system including a plurality of actuator systems and a brake ECU that controls brake actuators of a vehicle, The brake ECU A system that receives a plurality of requests including accelerations from a plurality of ADAS applications external to the brake ECU, arbitrates the plurality of requests including accelerations, calculates a request including a force based on the arbitration result, and selectively distributes the request including the force to at least one of the plurality of actuator systems, which include an actuator system including the brake actuator and an actuator system including an actuator controlled by an ECU different from the brake ECU.

5. A control method executed by a brake ECU that controls a brake actuator of a vehicle, comprising: A control method comprising: receiving a plurality of requests including accelerations from a plurality of ADAS applications external to the brake ECU; arbitrating the plurality of requests including accelerations; calculating a request including force based on the arbitration result; and selectively distributing the request including force to at least one of a plurality of actuator systems including an actuator system including the brake actuator and an actuator system including an actuator controlled by an ECU different from the brake ECU.

6. A vehicle comprising the brake ECU according to claim 2.

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