Control device, method, program, and vehicle

Abstract

To provide a controller which can improve steering control of a driving support device.SOLUTION: A controlling device mounted on a vehicle comprises: a receiving part which receives a plurality of first requests from a driving support system and receives operational states of a plurality of actuator systems from the actuator systems; an arbitration part which arbitrates the plurality of first requests; a calculation part which calculates a second request based on a result of the arbitration conducted by the arbitration part; and a first output part which outputs the second request to at least one of the plurality of actuator systems. The first request includes a request in a travel direction of the vehicle and a request in a cross direction of the vehicle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a control device for controlling the movement of a vehicle. [Background technology]

[0002] A vehicle may be equipped with a plurality of vehicle driving assistance devices that output control commands to control the motion of the vehicle in order to assist the driving of the vehicle. A vehicle control device that arbitrates control commands from such a plurality of driving assistance devices has been proposed. For example, Patent Document 1 discloses a vehicle control device that arbitrates a steering command from a collision avoidance assistance device, which is a driving assistance device that assists the user in driving the vehicle to avoid colliding with an obstacle, and a steering command from a lane departure avoidance assistance device, which is a driving assistance device that assists the user in driving the vehicle to stay within the lane. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-30472 Summary of the Invention [Problem to be solved by the invention]

[0004] When a driving assistance device performs steering control using the steering wheel angle as a target control amount, it is possible to improve steering control by obtaining the actual steering wheel angle, which is the current actual steering wheel angle of the vehicle, and using that information for control. However, there are limitations to how well the actual steering wheel angle can be obtained, and there are also limitations to the improvement of steering control.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a control device that can improve steering control of a driving assistance device. [Means for solving the problem]

[0006] In order to solve the above problem, one aspect of the disclosed technology is a control device mounted on a vehicle, the control device including: a reception unit that receives a plurality of first requests from a driving assistance system and receives operation states of the actuator systems from a plurality of actuator systems; an arbitration unit that arbitrates the plurality of first requests; a calculation unit that calculates a second request based on a result of the arbitration by the arbitration unit; and a first output unit that outputs the second request to at least one of the plurality of actuator systems; a second output unit that outputs an actual steering angle of the vehicle derived based on information representing a motion state of the vehicle to a driving assistance system; wherein the first request includes a request in the vehicle's traveling direction and a request in the vehicle's lateral direction. [Effects of the Invention]

[0007] According to the control device (vehicle control device) mounted on the vehicle of the present disclosure, an actual steering wheel angle that can be suitably used for steering control that reflects the vehicle's motion state is derived and provided to the driving assistance device, thereby improving steering control by the driving assistance device. [Brief explanation of the drawings]

[0008] [Figure 1] A functional block diagram of a vehicle control device and its peripheral components according to an embodiment. [Figure 2] 1 is a flowchart of a process executed by a vehicle control device according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0009] The vehicle control device according to the present disclosure preferably derives an actual steering angle based on the vehicle's motion state and provides the actual steering angle to a driving assistance device. Deriving the actual steering angle based on the vehicle's motion state requires relatively advanced calculations based on the vehicle's unique characteristics, but since multiple driving assistance devices do not need to individually implement and execute such derivation processing, development costs and processing loads can be reduced.

[0010] (Embodiment) [composition] Fig. 1 is a functional block diagram of a vehicle control device 20 and its peripheral units according to one embodiment. The functional block illustrated in Fig. 1 includes a plurality of control request units 11 to 13, the vehicle control device 20, a powertrain control unit 31, a brake control unit 32, a steering control unit 33, and actuators 41 to 43. These components are communicably connected via an in-vehicle network such as a Controller Area Network (CAN) or Ethernet (registered trademark). Note that the arrows in Fig. 1 are merely illustrative of the flow of information, and the actual connection of the communication lines is not limited thereto.

[0011] The control request units 11 to 13 are components (driving assistance devices) that execute driving assistance applications to realize vehicle driving assistance functions such as automatic driving, automatic parking, adaptive cruise control, lane keep assist, and collision mitigation braking. The control request units 11 to 13 are realized by a computer such as an ECU (Electronic Control Unit) that has a processor such as a CPU and a memory. The multiple control request units 11 to 13 each realize a different driving assistance function and can operate simultaneously. The number of control request units implemented in the vehicle is not limited to three as shown in FIG. 1, and may be two or less, or four or more. The control request units 11 to 13 output control commands to request the operation of the actuators 41 to 43.

[0012] The control request units 11 to 13 each determine some or all of the control content related to the vehicle's motion, such as "running," "turning," and "stopping," according to the respective driving assistance functions, and output the control commands. The control commands are, for example, a required value for the vehicle's motion in the forward direction for "running" and "stopping," and a required value for the vehicle's lateral motion for "turning." The required value for the forward motion is specifically expressed, for example, as the acceleration in the forward direction as a target control amount. The required value for the lateral motion is specifically expressed, for example, as any one of lateral acceleration, yaw rate, steering angle, etc., according to the specifications of the driving assistance application.

[0013] The vehicle control device 20 determines control details related to the vehicle's motion, such as "running," "turning," and "stopping," based on control commands from the control request units 11-13, and issues necessary instructions to the powertrain control unit 31, the brake control unit 32, and the steering control unit 33 (and a shift control unit, not shown, that controls the shift position) based on the determined control details, thereby functioning as a motion manager or as part of the motion manager to appropriately control actuators 41-43 related to the vehicle's motion and control the vehicle's motion. The vehicle control device 20 may alternatively be a device that exclusively controls the lateral motion of the vehicle. The vehicle control device 20 includes an arbitration unit 21, multiple instruction output units 22-24, and an actual steering angle derivation unit 25.

[0014] The arbitration unit 21 acquires the control commands output by the control request units 11 to 13 (driving support devices), and arbitrates the acquired control commands.

[0015] As the arbitration process, the arbitration unit 21 may, for example, select one control command from a plurality of control commands acquired based on a predetermined selection criterion, or set a new control command based on the acquired plurality of control commands. The result of this arbitration may be fed back from the arbitration unit 21 to each of the control request units 11 to 13. The arbitration unit 21 may also perform the arbitration process based on information indicating the operating states of the actuators 41 to 43 and availability, which is the current operable performance range, notified from a powertrain control unit 31, a brake control unit 32, and a steering control unit 33, which will be described later.

[0016] Furthermore, based on the control command obtained through the arbitration, the arbitration unit 21 can instruct one or more of the powertrain control unit 31, the brake control unit 32, and the steering control unit 33 to perform control of the vehicle movement requested by the driving assistance application via the instruction output units 22 to 24. The lateral movement of the vehicle can typically be achieved by controlling the steering of the steering device. The movement of the vehicle in the forward direction can be achieved by controlling the generation of braking force by the brake device and the generation of driving force or braking force by the powertrain, either alone or in combination. Note that the arbitration unit 21 may issue instructions for control of the lateral movement of the vehicle based on information indicating the operating states and availability of the actuators 41 to 43 acquired from the powertrain control unit 31, the brake control unit 32, and the steering control unit 33 via the instruction output units 22 to 24.

[0017] The instruction output unit 22 generates instruction information for causing the actuators 41 constituting the powertrain to generate a driving force or a braking force, based on the control command reconciled by the reconciliation unit 21. The instruction information generated by the instruction output unit 22 is acquired by the powertrain control unit 31.

[0018] The instruction output unit 23 generates instruction information for causing the actuator 42 constituting the brake device to generate a braking force, based on the control command reconciled by the reconciliation unit 21. The instruction information generated by the instruction output unit 23 is acquired by the brake control unit 32.

[0019] The instruction output unit 24 generates instruction information for causing the actuator 43 constituting the steering device to generate a steering angle based on the control command reconciled by the reconciliation unit 21. The instruction information generated by the instruction output unit 24 is acquired by the steering control unit 33.

[0020] The powertrain control unit 31 generates a driving force instructed by the instruction output unit 22 by controlling the operation of an actuator 41, which is one of the drive actuators and constitutes the powertrain. The powertrain control unit 31 may be realized by, for example, one or a combination of an engine control ECU, a hybrid control ECU, a transmission ECU, etc., depending on the configuration of the powertrain. While FIG. 1 illustrates one actuator 41 as a control target of the powertrain control unit 31, the number of actuators controlled by the powertrain control unit 31 may be two or more depending on the configuration of the vehicle's powertrain. Examples of actuators 41 that constitute the powertrain include an engine, a drive motor, a clutch, a transmission, and a torque converter. The powertrain control unit 31 also acquires information about the operating state of the actuator 41 based on a signal output from the actuator 41 or a measurement value obtained by a sensor. Examples of the information about the operating state of the actuator include information indicating the availability of the actuator and information indicating a monitor value of the driving force generated by the actuator. The information about the operating state of the actuator 41 acquired by the powertrain control unit 31 is acquired by the instruction output unit 22.

[0021] The brake control unit 32 generates the braking force instructed by the instruction output unit 23 by controlling the actuators 42 (for example, independently controlling all four wheels or independently controlling two left and two right wheels) that operate the brake devices provided on each wheel. These brake actuators include hydraulic brakes that can distribute braking force between the left and right wheels, and regenerative brakes such as in-wheel motors (IWM). The brake control unit 32 is realized, for example, by a brake control ECU. The brake control unit 32 receives output values from wheel speed sensors provided on each wheel. The brake control unit 32 also acquires information about the operating state of the actuators 42 based on signals output from the actuators 42 or values measured by the sensors. Examples of the information about the operating state of the actuators 42 include the above-mentioned information indicating availability and information indicating a monitored value of the braking force achieved by the actuators 42, as well as information specific to the actuators 42, such as whether the temperature of the brake pads is transitioning toward overheating. The information about the operating state of the actuators 42 acquired by the brake control unit 32 is acquired by the instruction output unit 23.

[0022] The steering control unit 33 controls the steering angle of the steering wheel by controlling an actuator 43 provided in an electric power steering (EPS), which is one type of steering actuator. The steering control unit 33 is realized, for example, by a power steering control ECU. The steering control unit 33 also acquires information about the operating state of the actuator 43 based on a signal output from the actuator 43 or a measurement value from a sensor. Examples of the information about the operating state of the actuator 43 include information indicating the availability described above and information indicating a monitor value of the steering angle achieved by the actuator 43. The information about the operating state of the actuator 43 acquired by the steering control unit 33 is acquired by the instruction output unit 24.

[0023] The actual steering angle derivation unit 25 derives the actual steering angle, which is the current actual steering angle of the vehicle, based on information representing the vehicle's motion state. Examples of the vehicle's motion state include at least one of lateral acceleration and yaw rate, vehicle speed, and vehicle body slip angle. This information can be acquired from various sensors equipped in the vehicle, such as a vehicle speed sensor, an acceleration sensor, and a yaw rate sensor, or can be derived appropriately based on values acquired from the various sensors. The actual steering angle derivation unit 25 derives the steering wheel tire turning angle from this information and the wheelbase specific to the vehicle. The actual steering angle derivation unit 25 further derives the actual steering angle by multiplying the derived steering wheel tire turning angle by a conversion coefficient from steering wheel tire turning angle to steering angle specific to the vehicle. Such vehicle-specific information may be stored in advance in the actual steering angle derivation unit 25 or may be acquired from another device equipped in the vehicle. The method for deriving the actual steering angle is not limited as long as it can be derived based on the vehicle's motion state.

[0024] The steering wheel angle is the rotation angle of the steering wheel, and the actual steering wheel angle can also be obtained directly from a steering wheel angle sensor provided on the steering wheel. However, because the steering wheel angle sensor generally must learn the midpoint of the steering wheel angle before using it for control, and because the entire steering system, including the steering wheel, has allowable flexure and play in its specifications, the output value of the steering wheel angle sensor has errors and may not adequately reflect the actual vehicle motion state. As a result, there are cases where the output value cannot be adequately used for feedback control, as described below. In this embodiment, the actual steering wheel angle derivation unit 25 can derive an actual steering wheel angle that adequately reflects the vehicle motion state based on the actual vehicle motion state.

[0025] The actual steering wheel angle derivation unit 25 can output the derived actual steering wheel angle and provide it appropriately to the control request units 11 to 13. For example, the actual steering wheel angle is provided to one of the control request units that outputs a control command requesting steering, the request value of which is expressed by the steering wheel angle.

[0026] [control] Further referring to Fig. 2, the steering control process executed by the vehicle control device 20 according to this embodiment will be described. Fig. 2 is a flowchart illustrating the steering control process executed by the vehicle control device 20. The steering control process shown in Fig. 2 can be executed, for example, at a predetermined cycle. As described above, the vehicle control device 20 not only controls lateral movement such as steering, but also controls movement in the traveling direction such as acceleration and deceleration, but here, only steering control will be described.

[0027] Here, as an example, the control request unit 11 is a driving assistance device that executes a lane keep assist function and outputs a required value of the steering amount expressed by a steering wheel angle as a control command requesting steering. The control request units 12 and 13 can also output required values of the steering amount expressed by a steering wheel angle, lateral acceleration, yaw rate, etc. as a control command requesting steering to execute a collision avoidance function, etc.

[0028] Step S201: The arbitration unit 21 of the vehicle control device 20 acquires the steering angle, yaw rate, etc. as control commands output by the control request units 11 to 13, and arbitrates the acquired control commands. Note that if only one control command is acquired from the control request units 11 to 13 during a certain waiting time, for example, this control command is adopted as the control command after arbitration. Here, as an example, the arbitration unit 21 selects the control command output by the control request unit 11 and outputs it as the control command after arbitration.

[0029] Step S202: The instruction output unit 24 of the vehicle control device 20 causes the steering control unit 33 to perform control for generating a steering angle in the actuator 43, which is a steering actuator, based on the control command after arbitration. If necessary, the instruction output unit 24 converts the required value included in the control command into a physical quantity or unit that the steering control unit 33 can accept.

[0030] Step S203: As described above, the actual steering angle derivation unit 25 of the vehicle control device 20 acquires information representing the vehicle's motion state, such as the lateral acceleration, yaw rate, vehicle speed, vehicle body slip angle, etc., and derives the actual steering angle, which is the current actual steering angle of the vehicle, based on this information.

[0031] Step S204: The actual steering wheel angle derivation unit 25 of the vehicle control device 20 outputs the derived actual steering wheel angle. In this embodiment, the current steering control is performed based on the control command output by the control request unit 11, so the actual steering wheel angle is acquired by the control request unit 11. This ends the steering control process.

[0032] The control request unit 11 performs feedback control using the acquired actual steering angle to determine the next control command to be output. For example, if there is a difference between the requested value of the steering angle included in the control command and the acquired actual steering angle, the control request unit 11 can change the requested value of the steering angle included in the next control command so as to eliminate the difference.

[0033] In this embodiment, the actual steering wheel angle derivation unit 25 of the vehicle control device 20 derives the actual steering wheel angle, and the control request unit 11 acquires the actual steering wheel angle. The vehicle control device 20 may additionally include derivation units that derive the yaw rate, lateral acceleration, etc. of the vehicle. The control request units 12 and 13 can appropriately acquire suitable values from the actual steering wheel angle, yaw rate, lateral acceleration, etc. from the derivation units according to the physical quantities and units included in the request values included in the respective control commands or the physical quantities and units used in the execution processing of the application, and use them for steering control. Note that for values such as yaw rate and lateral acceleration whose values can be acquired with relatively high accuracy from various sensors, the control request units may directly acquire them from the various sensors.

[0034] [Actions and Effects] As described above, the vehicle control device according to this embodiment can provide the actual steering angle of the vehicle to the control request unit (driving assistance device). The driving assistance device can obtain the actual steering angle as feedback for the control command and determine the next control command based on this. This can improve steering accuracy and control stability, thereby improving ride comfort. Furthermore, when a state in which steering control is being performed by one driving assistance device is switched to a state in which steering control is being performed by another driving assistance device as a result of arbitration, the other driving assistance device can obtain the actual steering angle of the vehicle early, allowing for smooth takeover of steering control before and after the switch.

[0035] In normal safe driving where the influence of vehicle body slip angle can be ignored, the actual steering angle derived based on the vehicle's motion state more accurately reflects the vehicle's motion state than the output value of the steering angle sensor, and is therefore suitable for use in steering control. However, deriving the actual steering angle based on the vehicle's motion state requires relatively advanced calculations based on vehicle-specific characteristics, and implementing and executing such derivation processing individually in each control request unit increases development costs and processing loads. In this embodiment, by providing the vehicle control unit with an actual steering angle derivation unit 25 that provides the actual steering angle, which is particularly difficult to derive, the development costs and processing loads of each control request unit can be reduced.

[0036] In the above embodiment, the actual steering wheel angle derivation unit 25 derives the actual steering wheel angle after the instruction output unit 24 and the steering control unit 33 control the actuator 43 in response to a control command from the control request unit 11, and provides the actual steering wheel angle to the control request unit 11 as feedback for the control command. However, the control request unit 11 may request the actual steering wheel angle at a desired timing, and the actual steering wheel angle derivation unit 25 may derive the actual steering wheel angle in response to the request and provide the actual steering wheel angle to the control request unit 11. For example, in the initial operation, the control request unit 11 may obtain the current actual steering wheel angle before determining a control command, and determine an initial control command based on the current actual steering wheel angle, thereby enabling more stable steering control. In this way, the trigger and timing for deriving and obtaining the actual steering wheel angle are not limited.

[0037] The above describes one embodiment of the disclosed technology, but the disclosed technology can be understood as a vehicle control device, a control method executed by a vehicle control device equipped with a processor and memory, a control program for executing the control method, a computer-readable non-transitory storage medium storing the control program, and a system including the vehicle control device, a control request unit, an actuator control unit, and an actuator, or a vehicle equipped with a vehicle control device. [Industrial Applicability]

[0038] The present invention can be used in a vehicle control device that controls the movement of a vehicle. [Explanation of symbols]

[0039] 11, 12, 13 Control request section 20 Vehicle control device 21 Mediation Department 22, 23, 24 Instruction output section 25 Actual steering angle derivation section 31 Powertrain control unit 32 Brake control unit 33 Steering control unit 41, 42, 43 Actuators

Claims

1. A control device mounted on a vehicle, a receiving unit that receives a plurality of first requests from the driving assistance system and receives operation states of the actuator systems from the plurality of actuator systems; an arbitration unit that arbitrates the plurality of first requests based on the operating state of the actuator system; a calculation unit that calculates a second request based on a result of arbitration by the arbitration unit; a first output unit that outputs the second request to at least one of the plurality of actuator systems; a second output unit that outputs an actual steering angle of the vehicle derived based on information representing a motion state of the vehicle to the driving assistance system, the first request includes a request in the direction of travel of the vehicle and a request in the lateral direction of the vehicle; A control device wherein the operating state of the actuator system includes a driving force realized by a driving actuator, a braking force realized by a braking actuator, and a steering angle realized by a steering actuator, each of which constitutes the plurality of actuator systems.

2. A control device as described in claim 1, wherein the information representing the vehicle's motion state includes at least one of lateral acceleration and yaw rate, vehicle speed, and vehicle body slip angle.

3. A method executed by a computer of a control device mounted on a vehicle, comprising: receiving a plurality of first requests from a driving assistance system and receiving operation states of the actuator systems from a plurality of actuator systems; arbitrating the plurality of first requests based on the operational state of the actuator system; calculating a second requirement based on the results of the arbitration; outputting the second request to at least one of the plurality of actuator systems; and outputting an actual steering angle of the vehicle derived based on information representing a motion state of the vehicle to the driving assistance system, the first requirement includes a requirement in the direction of travel of the vehicle and a requirement in the lateral direction of the vehicle; The method, wherein the operating states of the actuator systems include a driving force realized by a driving actuator, a braking force realized by a braking actuator, and a steering angle realized by a steering actuator, each of which constitutes the plurality of actuator systems.

4. A program to be executed by a computer of a control device mounted on a vehicle, receiving a plurality of first requests from a driving assistance system and receiving operation states of the actuator systems from a plurality of actuator systems; arbitrating the plurality of first requests based on the operational state of the actuator system; calculating a second requirement based on the results of the arbitration; outputting the second request to at least one of the plurality of actuator systems; and outputting an actual steering angle of the vehicle derived based on information representing a motion state of the vehicle to the driving assistance system, the first requirement includes a requirement in the direction of travel of the vehicle and a requirement in the lateral direction of the vehicle; The operating state of the actuator system includes a driving force realized by a driving actuator, a braking force realized by a braking actuator, and a steering angle realized by a steering actuator, which respectively constitute the plurality of actuator systems.

5. A vehicle equipped with the control device according to claim 1 or 2.

Images