Vehicle control device, vehicle control method, and vehicle control system

Abstract

In one embodiment, a vehicle control device, a vehicle control method, and a vehicle control system according to the present invention acquire a first angle, which is an angle formed by the orientation of a vehicle and the direction of travel of the vehicle, acquire an avoidance path for avoiding an object located in front of the vehicle, and when the vehicle is caused to travel along the avoidance path, control the vehicle to travel along the avoidance path. And a controller configured to execute a first angle control for bringing the first angle close to a predetermined reference angle, and selectively switch a control target of the first angle control to a steering actuator or either a brake drive actuator or a steering actuator on the basis of a physical quantity caused by a tire force of the vehicle. As a result, it is possible to improve the precision of following the avoidance path.

Description

Technical Field

[0001] The invention relates to a vehicle control device, a vehicle control method and a vehicle control system. Background Art

[0002] The vehicle control device of Patent Document 1 includes a travel path control unit that updates a target travel path of the vehicle and an automatic emergency avoidance control unit that executes an automatic emergency avoidance control process for automatically operating a predetermined control system to avoid a collision with an obstacle.

[0003] Furthermore, the driving path control unit corrects the target driving path, calculates a plurality of corrected driving paths to avoid obstacles, evaluates and selects one corrected driving path through a predetermined evaluation function, and generates a first request signal in such a manner that the vehicle drives on the corrected driving path. On the other hand, the automatic emergency avoidance control unit generates a second request signal.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6525402 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, when the vehicle control device performs path following control to make the vehicle follow an avoidance path for avoiding an object in front of the vehicle, if the angle between the vehicle orientation and the vehicle's traveling direction is large, the accuracy of following the avoidance path may decrease.

[0009] The present invention has been made in view of the actual situation in the past, and an object of the present invention is to provide a vehicle control device, a vehicle control method, and a vehicle control system capable of improving the accuracy of following an avoidance path.

[0010] Means for solving problems

[0011] According to the vehicle control device, vehicle control method and vehicle control system involved in the present invention, in one mode, a first angle formed by the orientation of the vehicle and the traveling direction of the vehicle is obtained, an avoidance course for avoiding an object located in front of the vehicle is obtained, and when a path following control is performed to make the vehicle follow the avoidance course, a first angle control is performed to make the first angle approach a prescribed reference angle, and based on a physical quantity caused by the tire force of the vehicle, the control object of the first angle control is selectively switched to a steering actuator, or to either a braking drive actuator or the steering actuator.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to improve the accuracy of following the avoidance path. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a block diagram showing a vehicle control system according to the first embodiment.

[0015] Figure 2 It is a diagram showing the operation of collision avoidance assistance based on the combination of AEB and ESS.

[0016] Figure 3 1 is a block diagram showing a steering assistance request value calculation unit according to the first embodiment.

[0017] Figure 4 1 is a block diagram showing a β angle minimization required value calculation unit according to the first embodiment.

[0018] Figure 5 : is a block diagram showing a control signal calculation unit according to the first embodiment.

[0019] Figure 6 1 is a flowchart showing a process of selecting a control device according to the first embodiment.

[0020] Figure 7 1 is a flowchart showing a process of selecting a control device according to the first embodiment.

[0021] Figure 8 1 is a flowchart showing a process of selecting a control device according to the first embodiment.

[0022] Fig. 9 The figure explains the recognition error of the lateral offset amount caused by the slip angle of the vehicle.

[0023] Fig.10 This is a diagram showing that the following error to the target path is reduced by reducing the vehicle slip angle.

[0024] Fig.11 This is a diagram showing the generation of a yaw moment based on the control of the lateral force of the front wheels and the longitudinal force of each wheel.

[0025] Fig.12 It is a block diagram showing a vehicle control system according to the second embodiment.

[0026] Fig.13 : is a block diagram showing a control signal calculation unit according to the second embodiment.

[0027] Fig.14: is a flowchart showing the control device selection process according to the second embodiment.

[0028] Fig.15 : is a flowchart showing the control device selection process according to the second embodiment.

[0029] Fig.16 : is a flowchart showing the control device selection process according to the second embodiment.

[0030] Fig.17 It is a block diagram showing a vehicle control system according to a third embodiment.

[0031] Fig.18 : is a block diagram showing a control signal calculation unit according to the third embodiment.

[0032] Fig.19 : is a flowchart showing the control device selection process according to the third embodiment.

[0033] Fig. 20 : is a flowchart showing the control device selection process according to the third embodiment.

[0034] Fig.21 It is a block diagram showing a vehicle control system according to a fourth embodiment.

[0035] Fig. 22 1 is a flowchart showing a control device selection process according to the fourth embodiment.

[0036] Fig.23 1 is a flowchart showing a control device selection process according to the fourth embodiment.

[0037] Fig.24 1 is a flowchart showing a control device selection process according to the fourth embodiment. DETAILED DESCRIPTION

[0038] Hereinafter, embodiments of a vehicle control device, a vehicle control method, and a vehicle control system according to the present invention will be described with reference to the drawings.

[0039] [First embodiment]

[0040] Figure 1 This is a block diagram showing one embodiment of a vehicle control system 200 mounted on a vehicle 100 such as a four-wheeled vehicle.

[0041] As will be described in detail later, the vehicle control system 200 is a system that performs collision avoidance assistance.

[0042] The vehicle control system 200 includes a braking device 300 for applying braking force to each wheel (a pair of front wheels and a pair of rear wheels) of the vehicle 100 , a front wheel steering device 400 for steering the front wheels of the vehicle 100 , and a vehicle control device 500 provided in the vehicle 100 .

[0043] The above-mentioned braking device 300 includes an actuator capable of individually controlling the braking force applied to each wheel by an electric signal.

[0044] Furthermore, the front wheel steering device 400 includes an actuator capable of controlling the steering angle of the front wheels by an electrical signal.

[0045] Here, the brake device 300 is a brake actuator that applies a braking force to each wheel among brake drive actuators that apply a braking force to each wheel of the vehicle 100 .

[0046] That is to say, in the present application, the brake drive actuator includes a brake actuator and a drive actuator, and the brake device 300 is equivalent to the brake actuator in the brake drive actuator.

[0047] The front wheel steering device 400 is a front wheel steering actuator that steers the front wheels among steering actuators that steer the wheels of the vehicle 100 .

[0048] The vehicle control device 500 includes a microcomputer 510 as a control unit that performs calculations based on input information and outputs calculation results.

[0049] The microcomputer 510 includes an MPU (Microprocessor Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, although not shown.

[0050] In addition, the microcomputer 510 can be renamed as MCU (Micro Controller Unit), processor, processing device, computing device, etc.

[0051] The vehicle 100 has various sensors for detecting the vehicle state, and the microcomputer 510 obtains signals output by the various sensors.

[0052] The vehicle 100 includes an acceleration sensor 101 , a gyro sensor 102 , a steering angle sensor 103 , a self-position recognition sensor 104 , an outside recognition sensor 105 , and a wheel speed sensor 106 as various sensors.

[0053] The acceleration sensor 101 is a sensor that detects acceleration in the behavior of the vehicle 100 , and detects front-rear acceleration, lateral acceleration (in other words, left-right acceleration), and up-down acceleration of the vehicle 100 .

[0054] The gyro sensor 102 is a sensor that detects an angular velocity in the behavior of the vehicle 100 , and detects a yaw rate, a roll rate, and a pitch rate of the vehicle 100 .

[0055] The steering angle sensor 103 detects a steering angle θ based on an operation of a driver of the vehicle 100 .

[0056] The own position recognition sensor 104 includes, for example, a GPS receiving unit that measures the latitude and longitude of the position of the vehicle 100 by receiving signals from a GPS satellite, and detects the position of the vehicle 100 .

[0057] The external recognition sensor 105 is a device that obtains external information of the vehicle 100, in other words, obtains information related to the driving environment of the road on which the vehicle 100 is traveling, and has, for example, a camera, radar, LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), etc.

[0058] The wheel speed sensor 106 is a sensor that detects the rotation speed of each wheel of the vehicle 100 .

[0059] The microcomputer 510 has a function of executing collision avoidance assistance for avoiding a collision between the vehicle 100 and an object (hereinafter referred to as an obstacle) located in the forward direction of travel or for reducing collision damage.

[0060] As collision avoidance assistance, microcomputer 510 executes AEB (Autonomous Emergency Braking) that automatically operates brake device 300 based on collision risk, and ESS (Emergency Steering Support) that causes vehicle 100 to follow an avoidance path automatically generated when a driver of vehicle 100 performs avoidance direction manipulation as a trigger.

[0061] Figure 2 The transition of the assistance action in the collision avoidance assistance based on the combination of AEB and ESS is exemplified.

[0062] In the collision avoidance assistance based on the combination of AEB and ESS, the microcomputer 510 gradually strengthens the collision avoidance assistance such as "warning to the driver" → "primary braking (preparatory braking) based on AEB" → "secondary braking (main braking) based on AEB" and "steering assistance based on ESS" according to the increase in the risk of collision with the obstacle recognized by the external recognition sensor 105.

[0063] In addition, in the following embodiments, it is described that the intervention timing of "steering assistance based on ESS" and the intervention timing of "secondary braking (formal braking) based on AEB" are the same intervention timing, but the intervention timing of "steering assistance based on ESS" may also be different from the intervention timing of "secondary braking (formal braking) based on AEB".

[0064] In other words, the intervention timing of "steering assistance by ESS" may be set independently from the intervention timing of the above-mentioned "primary braking by AEB (preparatory braking)" and "secondary braking by AEB (main braking)".

[0065] Figure 1 Functional blocks for the above-mentioned collision avoidance assistance are shown.

[0066] The microcomputer 510 includes functional units including a steering assist request value calculation unit 520 that performs the function of ESS, a braking assist request value calculation unit 530 that performs the function of AEB, a control signal calculation unit 540 , a vehicle slip angle calculation unit 550 , and a control device selection unit 560 .

[0067] The control signal calculation unit 540 obtains the steering assistance request value output by the steering assistance request value calculation unit 520 and the braking assistance request value output by the braking assistance request value calculation unit 530, and calculates the braking control signal for each wheel and the front wheel steering control signal based thereon.

[0068] Furthermore, the control signal calculation unit 540 outputs a braking control signal to the braking device 300 , and outputs a front wheel steering control signal to the front wheel steering device 400 .

[0069] Furthermore, when the brake device 300 generates a braking force according to the control current, the control signal calculation unit 540 can output the braking control current as the braking control signal.

[0070] Likewise, when the front wheel steering device 400 generates a steering force according to the control current, the control signal calculation unit 540 can output the front wheel steering control current as the front wheel steering control signal.

[0071] The vehicle slip angle calculation unit 550 calculates a first angle (hereinafter referred to as a vehicle slip angle β) which is an angle formed between the orientation of the vehicle 100 and the traveling direction of the vehicle 100 .

[0072] The vehicle slip angle calculation unit 550 obtains information on the longitudinal acceleration and the lateral acceleration detected by the acceleration sensor 101 and information on the yaw rate detected by the gyro sensor 102 , and performs a calculation process to estimate the vehicle slip angle β based on the information.

[0073] The steering assist requirement value calculation unit 520 has a path following control function (in other words, ESS function), which is a function of generating an avoidance path for avoiding obstacles triggered by the driver's steering operation and calculating the steering requirement value for making the vehicle 100 follow the avoidance path.

[0074] The steering assist required value calculation unit 520 has a vehicle slip angle control function of calculating a steering required value and a braking required value for obtaining a yaw moment required to bring the vehicle slip angle β close to a predetermined reference angle βTH when the vehicle 100 follows the avoidance path.

[0075] The control device selector 560 obtains a signal of the vehicle slip angle β from the vehicle slip angle calculator 550 , and outputs a control device selector signal, which is a signal for indicating a control target in the vehicle slip angle control, to the steering assistance request value calculator 520 .

[0076] Here, the control device selection unit 560 selectively switches the control target in the vehicle slip angle control function to the front wheel steering device 400 or to both the braking device 300 and the front wheel steering device 400 based on the vehicle slip angle β.

[0077] In other words, the control device selection unit 560 has a function of selectively switching the control object in the vehicle slip angle control to the steering actuator, or to both the brake drive actuator and the steering actuator, based on the physical quantity caused by the tire force, namely the vehicle slip angle β.

[0078] As a method of path following control, for example, there is a control method of feeding back the lateral position deviation between the predicted position of the vehicle at the forward gaze point and the target path.

[0079] When avoiding a collision, the vehicle slip angle β increases, thereby increasing the error in the predicted position of the vehicle at the forward focus point position and increasing the following error with respect to the target path.

[0080] Therefore, when executing the path following control for causing the vehicle 100 to follow the avoidance path, the steering assistance request value calculation unit 520 performs the vehicle body slip angle control for reducing the vehicle slip angle β, thereby improving the accuracy of following the avoidance path.

[0081] Furthermore, by virtue of the function of the control device selection unit 560 for selectively switching the control object in the vehicle slip angle control according to the vehicle slip angle β, it is possible to select the control object taking into account the tire force of each wheel required for obtaining the yaw moment required to reduce the vehicle slip angle β and the limit of the tire force of each wheel, thereby stably achieving the minimization of the vehicle body slip angle β under various conditions.

[0082] Therefore, the microcomputer 510 can make the vehicle 100 follow the avoidance path with high accuracy in each situation, and can realize the steering assist function for collision avoidance at a high level.

[0083] The following is a detailed description Figure 1 The functional blocks shown.

[0084] Figure 3 2 is a functional block diagram showing details of the steering assistance request value calculation unit 520 .

[0085] The steering assistance request value calculation unit 520 includes a β angle minimization request value calculation unit 521 , an avoidance path following request value calculation unit 522 , and an adding unit 523 .

[0086] The avoidance path following requirement value calculation unit 522 obtains information on the steering angle θ detected by the steering angle sensor 103, the external recognition state based on the external recognition sensor 105 (in detail, information related to the position and size of the obstacle), the position information of the vehicle 100 based on the self-position recognition sensor 104, and the wheel speed information detected by the wheel speed sensor 106 (in other words, vehicle speed information).

[0087] In addition, the avoidance path following request value calculation unit 522 obtains a signal of a brake assist flag indicating the operating state of the AEB from the brake assist request value calculation unit 530, and outputs a signal of an avoidance path generation flag indicating the generation state of the avoidance path (in other words, the operating state of the ESS) to the brake assist request value calculation unit 530.

[0088] When the AEB enters the secondary braking state, the avoidance path following required value calculation unit 522 generates an avoidance path for avoiding the obstacle based on the positional relationship between the vehicle and the obstacle, the speed of the vehicle 100 and the steering angle θ (in other words, the driver's avoidance direction steering information).

[0089] Furthermore, as described above, the steering assistance required value calculation unit 520 can set the timing of intervention of the steering assistance independently of the operation of the AEB by the braking assistance required value calculation unit 530 .

[0090] In this case, the avoidance path following requirement value calculation unit 522 independently determines the intervention timing based on the collision risk and other indicators and generates an avoidance path, thereby omitting the exchange of signals of the brake assist flag and the avoidance path generation flag between the avoidance path following requirement value calculation unit 522 and the brake assist requirement value calculation unit 530.

[0091] When the avoidance path is generated, the avoidance path following requirement value calculation unit 522 calculates a lateral position deviation Δy between the predicted position of the vehicle at the forward attention point and the avoidance path (in other words, a following error of the avoidance path).

[0092] Next, avoidance path following required value calculation unit 522 calculates and outputs the required lateral force of the front wheels required for vehicle 100 to follow the avoidance path (in other words, the required lateral force of the steering assist amount or the required lateral force of the ESS amount) based on lateral position deviation Δy.

[0093] The β angle minimization required value calculation unit 521 is a functional unit that executes the vehicle slip angle control.

[0094] The β angle minimization required value calculation unit 521 obtains the vehicle slip angle β and the control device selection signal, and outputs the required lateral force of the front wheels and the required front and rear forces of each wheel as the steering assist amount for obtaining the yaw moment required to make the vehicle slip angle β close to a predetermined reference angle βTH.

[0095] The adding unit 523 obtains the required lateral force of the front wheel output by the avoidance path following required value calculating unit 522 and the required lateral force of the front wheel output by the β angle minimization required value calculating unit 521, and outputs their added value to the control signal calculating unit 540 as the required lateral force of the front wheel in the steering assist.

[0096] On the other hand, the required front-rear force of each wheel outputted from the β angle minimization required value calculation unit 521 is directly outputted to the control signal calculation unit 540 as the required front-rear force of each wheel in the steering assistance.

[0097] Figure 4 2 is a functional block diagram showing details of the β angle minimization required value calculation unit 521 .

[0098] The β angle minimization required value calculation unit 521 includes a comparison unit 521A, a first conversion unit 521B, a second conversion unit 521C, and a front-rear force output switching unit 521D.

[0099] The comparison unit 521A obtains information on the vehicle body slip angle β [deg] and the reference angle β TH [deg] calculated by the vehicle slip angle calculation unit 550 , calculates a deviation Δβ [deg] between the vehicle body slip angle β and the reference angle β TH , and outputs information on the obtained deviation Δβ.

[0100] The first conversion unit 521B obtains information on the deviation Δβ and converts the deviation Δβ into a required front-rear force for each wheel.

[0101] That is, the required front-rear force of each wheel obtained by the first conversion unit 521B is the front-rear force required on each wheel in order to obtain the yaw moment required to make the vehicle body slip angle β equal to the reference angle βTH.

[0102] The second conversion unit 521C obtains information on the deviation Δβ and converts the deviation Δβ into a required lateral force for the front wheels.

[0103] That is, the required lateral force of the front wheels obtained by the second conversion unit 521C is the lateral force required on the front wheels in order to obtain the yaw moment required to make the vehicle body slip angle β equal to the reference angle βTH.

[0104] In addition, the reference angle βTH acquired by the comparison unit 521A is set to zero or a value close to zero.

[0105] Furthermore, when the reference angle βTH is zero, the comparison unit 521A outputs the vehicle body slip angle β calculated by the vehicle slip angle calculation unit 550 as it is.

[0106] Therefore, when the reference angle βTH is zero, the first conversion unit 521B and the second conversion unit 521C calculate the longitudinal force of each wheel and the lateral force of the front wheel for obtaining the yaw moment required to make the vehicle body slip angle β zero.

[0107] The front-rear force output switching unit 521D obtains the information of the required front-rear force of each wheel obtained by the first conversion unit 521B and the control device selection signal output by the control device selection unit 560 .

[0108] Here, the control device selection signal is set as a binary signal.

[0109] Furthermore, when the control device selection signal is 1, it indicates that both the braking device 300 and the front wheel steering device 400 are selected as the control objects in the vehicle slip angle control.

[0110] On the other hand, when the control device selection signal is 0, it means that only the front wheel steering device 400 is selected as the control target in the vehicle slip angle control.

[0111] When the control device selection signal is 1 and the control object in the vehicle slip angle control includes the braking device 300, the front and rear force output switching unit 521D outputs the information of the required front and rear force of each wheel calculated by the first conversion unit 521B as the required front and rear force of each wheel of the vehicle slip angle control amount (specifically, the braking requirement value).

[0112] When the control device selection signal is 0 and the control target in the vehicle slip angle control does not include the brake device 300, the front-rear force output switching unit 521D outputs the required front-rear force of each wheel of the vehicle slip angle control amount as 0.

[0113] In other words, the front and rear force output switching unit 521D switches, according to the control device selection signal, whether to directly output the required front and rear force of each wheel obtained by the first conversion unit 521B or to output the required front and rear force of each wheel as zero, thereby switching whether to add the braking device 300 to the control object in the vehicle slip angle control.

[0114] The required front and rear force of each wheel of the vehicle slip angle control amount output by the front and rear force output switching unit 521D is directly output from the steering assistance required value calculation unit 520 as the required front and rear force of each wheel of the steering assistance amount.

[0115] On the other hand, the required lateral force of the front wheels corresponding to the vehicle slip angle control amount obtained by the second conversion unit 521C is output to the addition unit 523 and added to the required lateral force of the front wheels obtained by the avoidance path following required value calculation unit 522 .

[0116] The adding unit 523 outputs the addition result to the control signal calculating unit 540 as the required lateral force of the steering assist amount.

[0117] Figure 1 The braking assist requirement value calculation unit 530 shown obtains the output of the external recognition sensor 105 (in other words, external recognition information), the output of the wheel speed sensor (in other words, information on the speed of the vehicle 100), and the signal of the avoidance path generation flag output by the steering assist requirement value calculation unit 520.

[0118] The brake assist required value calculation unit 530 calculates and outputs the required front and rear force of each wheel required to avoid a collision or reduce collision damage (in other words, the required front and rear force of the brake assist amount or the required front and rear force of the AEB amount).

[0119] That is, the brake assist requirement value calculation unit 530 detects obstacles such as vehicles and objects ahead using the external recognition sensor 105 such as a camera or radar, thereby automatically generating a braking force to avoid a collision or reduce collision damage.

[0120] Furthermore, the brake assist request value calculation unit 530 outputs a signal of a brake assist flag indicating the activation state of the AEB to the steering assist request value calculation unit 520 .

[0121] Furthermore, when the steering assistance required value calculation unit 520 independently sets the timing of intervention of the steering assistance, the output of the braking assistance flag from the braking assistance required value calculation unit 530 to the steering assistance required value calculation unit 520 can be omitted.

[0122] The control signal calculation unit 540 obtains signals of the required longitudinal force and the required lateral force of the steering assistance amount from the steering assistance required value calculation unit 520 , and obtains signals of the required longitudinal force of the braking assistance amount from the braking assistance required value calculation unit 530 .

[0123] Furthermore, the control signal calculation unit 540 acquires the output of the wheel speed sensor (in other words, information on the speed of the vehicle 100 ).

[0124] Furthermore, the control signal calculation unit 540 outputs a braking control signal for each wheel to the braking device 300 , and outputs a steering control signal for the front wheels to the front wheel steering device 400 .

[0125] Figure 5 It is a block diagram showing the details of the control signal calculation unit 540 .

[0126] The adding unit 541 obtains the signal of the required front-rear force of the steering assist amount and the signal of the required front-rear force of the braking assist amount, and outputs the added value thereof as the signal of the required front-rear force of the final collision avoidance assist amount.

[0127] The first conversion unit 542 converts the signal of the required front and rear force of the collision avoidance assistance amount output by the addition unit 541 into a brake control signal for each wheel.

[0128] The second conversion unit 543 obtains the signal of the required lateral force of the front wheels of the steering assist amount, and converts the signal of the required lateral force of the front wheels of the steering assist amount into a steering control signal for the front wheels.

[0129] The comparison unit 544 acquires a vehicle speed signal based on the output of the wheel speed sensor 106 , compares the acquired vehicle speed signal with a threshold value, and outputs a switching signal for switching between output and stop of the requested value of the collision avoidance assistance amount.

[0130] The switching unit 545 obtains the braking control signal of each wheel output from the first conversion unit 542 , the steering control signal of the front wheel output from the second conversion unit 543 , and the switching signal output from the comparison unit 544 .

[0131] Moreover, the switching unit 545 switches the output of the braking control signal of each wheel output by the first conversion unit 542 and the steering control signal of the front wheel output by the second conversion unit 543 to the rear stage (braking device 300, front wheel steering device 400) and stops it based on the switching signal.

[0132] Here, when the vehicle speed is in a low speed state below a threshold, the switching unit 545 stops outputting the braking control signal of each wheel output by the first conversion unit 542 and the steering control signal of the front wheel output by the second conversion unit 543 to the rear stage by setting the braking control signal output to the braking device 300 and the steering control signal output to the front wheel steering device 400 to zero.

[0133] On the other hand, when the vehicle speed exceeds the threshold, the switching unit 545 directly outputs the braking control signal of each wheel output by the first conversion unit 542 and the front wheel steering control signal output by the second conversion unit 543 to the braking device 300 and the front wheel steering device 400.

[0134] That is, since the effectiveness of the collision avoidance assistance becomes low when the vehicle speed is sufficiently low, the control signal calculation unit 540 stops the braking control and the steering control for the collision avoidance assistance.

[0135] Figure 6 - Figure 8 The flowchart shows the process of selecting the control object by the control device selection unit 560 and the process of the vehicle slip angle control by the β angle minimization required value calculation unit 521.

[0136] In step S601 , the microcomputer 510 determines that the collision risk is high based on the output of the environment recognition sensor 105 , and determines whether to activate the brake assist by AEB.

[0137] Then, if the AEB is in the operating state, the ESS may be activated by the driver's steering operation, so the microcomputer 510 proceeds to step S602 and thereafter.

[0138] On the other hand, if the AEB is not in the operating state, the prerequisite for operating the ESS is not satisfied, so the microcomputer 510 directly terminates this routine.

[0139] Furthermore, when the steering assistance request value calculation unit 520 independently sets the timing of intervention of the steering assistance, the microcomputer 510 independently determines the prerequisite for activating the ESS based on indicators such as the collision risk in step S601 .

[0140] In step S602 , the microcomputer 510 calculates the front-rear direction speed and the lateral speed [km / h] of the vehicle 100 based on the output of the acceleration sensor 101 and the output of the gyro sensor 102 .

[0141] Next, in step S603 , the microcomputer 510 determines whether the speed in the front-rear direction obtained in step S602 is greater than a threshold value.

[0142] Here, when the speed in the front-rear direction is below the threshold, the microcomputer 510 determines that the estimation condition of the vehicle slip angle β is not satisfied. In other words, the estimation accuracy of the vehicle slip angle β cannot be ensured and the vehicle slip angle control cannot be performed, and the routine is directly terminated.

[0143] On the other hand, when the speed in the front-rear direction is greater than the threshold value, the microcomputer 510 proceeds to step S604.

[0144] In step S604 , microcomputer 510 obtains vehicle slip angle β based on detected values ​​of vehicle speed, yaw rate, lateral acceleration, etc., and obtains vehicle slip angular velocity α by temporally differentiating the obtained vehicle slip angle β.

[0145] That is, when the speed in the front-rear direction is greater than the threshold value, microcomputer 510 acquires vehicle slip angle β and vehicle slip angular velocity α, which are physical quantities caused by tire force of vehicle 100 .

[0146] Furthermore, microcomputer 510 obtains vehicle slip angle β and vehicle slip angular velocity α with signs for distinguishing left and right directions.

[0147] Next, in step S605 , the microcomputer 510 determines whether the absolute value of the vehicle slip angle β is smaller than the first threshold βTH1 ( βTH1 > 0) and the absolute value of the vehicle slip angular velocity α is smaller than the threshold αTH1 ( αTH1 > 0).

[0148] In other words, in step S605, microcomputer 510 determines whether the vehicle slip angle β is sufficiently small and lower than the threshold value, and whether the vehicle slip angle β shows a decreasing trend.

[0149] If the microcomputer 510 determines in step S605 that the absolute value of the vehicle slip angle β is smaller than the first threshold βTH1 and the absolute value of the vehicle slip angular velocity α is smaller than the threshold αTH1 , the microcomputer 510 proceeds to step S607 .

[0150] In step S607 , the microcomputer 510 calculates the required lateral force of the front wheels for obtaining the yaw moment required to bring the vehicle slip angle β close to the reference angle βTH based on the deviation Δβ between the vehicle slip angle β and the reference angle βTH (eg, βTH=0 [deg]).

[0151] That is, when the absolute value of the vehicle slip angle β is smaller than the first threshold βTH1 and the absolute value of the vehicle slip angular velocity α is smaller than the threshold αTH1, the yaw moment required to bring the vehicle slip angle β close to the reference angle βTH can be generated by steering control of the front wheels alone.

[0152] Therefore, when the absolute value of the vehicle slip angle β is smaller than the first threshold βTH1 and the absolute value of the vehicle slip angular velocity α is smaller than the threshold αTH1, the microcomputer 510 selects only the front wheel steering device 400 as the control target of the vehicle slip angle control.

[0153] Next, microcomputer 510 proceeds to step S608 to determine whether the absolute value of steering angle θ by the driver is greater than threshold θTH and the absolute value of steering angular velocity ω obtained by time-differentiating steering angle θ is greater than threshold ωTH.

[0154] Here, the process in step S608 is a process for determining whether or not the driver's steering operation, which is a trigger for starting the operation of the ESS, has been performed.

[0155] When the absolute value of the steering angle θ is greater than the threshold value θTH and the absolute value of the steering angular velocity ω is greater than the threshold value ωTH, the microcomputer 510 determines that the operating condition of the ESS is satisfied and proceeds to step S609 .

[0156] In step S609, the microcomputer 510 outputs a front wheel steering control signal based on the required lateral force of the front wheel of the vehicle slip angle control amount obtained in step S607.

[0157] On the other hand, in step S608, if microcomputer 510 determines that the absolute value of steering angle θ is greater than threshold value θTH and steering angular velocity ω is greater than threshold value ωTH, it determines that the operating condition of ESS is not satisfied, does not execute vehicle slip angle control, and ends this routine.

[0158] If the microcomputer 510 determines in step S605 that the absolute value of the vehicle slip angle β is smaller than the first threshold βTH1 and the absolute value of the vehicle slip angular velocity α is smaller than the threshold αTH1 is not satisfied, the process proceeds to step S606 .

[0159] In step S606 , the microcomputer 510 determines whether the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 (βTH2>βTH1>0), and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1 .

[0160] In other words, in step S606, microcomputer 510 determines whether vehicle slip angle β is an angle within a predetermined range that does not include zero, and whether vehicle slip angle β shows an increasing trend.

[0161] If the microcomputer 510 determines in step S606 that the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1, the process proceeds to step S610.

[0162] In step S610, microcomputer 510 calculates the required lateral force of the front wheels and the required front-rear force (required braking force) of each wheel for obtaining the yaw moment required to bring vehicle slip angle β close to reference angle βTH based on deviation Δβ between vehicle slip angle β and reference angle βTH.

[0163] That is, the state in which the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1, is to generate the yaw moment required to make the vehicle slip angle β close to the reference angle βTH. In addition to the directional steering control of the front wheels, it is also required to control the state of the front and rear forces of each wheel.

[0164] Therefore, when the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1, the microcomputer 510 selects both the front wheel steering device 400 and the braking device 300 as the control objects of the vehicle slip angle control.

[0165] Next, the microcomputer 510 proceeds to step S611 and determines whether the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH in the same manner as step S608 .

[0166] When the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH, the microcomputer 510 proceeds to step S612.

[0167] In step S612, microcomputer 510 outputs a steering control signal for the front wheels based on the required lateral force of the front wheels of the vehicle slip angle control amount, and outputs a braking control signal for each wheel based on the required front-rear directional force of each wheel of the vehicle slip angle control amount.

[0168] On the other hand, when microcomputer 510 determines in step S611 that the conditions that steering angle θ is greater than threshold value θTH and steering angular velocity ω is greater than threshold value ωTH are not satisfied, this routine ends without executing vehicle slip angle control.

[0169] If microcomputer 510 determines in step S606 that the conditions that the absolute value of vehicle slip angle β is greater than first threshold βTH1 and less than second threshold βTH2 and the absolute value of vehicle slip angular velocity α is greater than threshold αTH1 are not satisfied, the process proceeds to step S613 .

[0170] In step S613, the microcomputer 510 calculates the required lateral force of the front wheels and the required longitudinal force (required braking force) of each rear wheel for obtaining the yaw moment required to bring the vehicle slip angle β close to the reference angle βTH based on the deviation Δβ between the vehicle slip angle β and the reference angle βTH.

[0171] When the microcomputer 510 determines in step S606 that the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1 are not satisfied, it is estimated that the lateral force of the front tire is saturated and there is no margin for generating front and rear force of the tire.

[0172] Therefore, the microcomputer 510 removes the front wheels from the objects of the longitudinal force control in the vehicle slip angle control, and controls the longitudinal force of each rear wheel in the vehicle slip angle control.

[0173] By switching the control object, it is possible to prevent an unstable control state from occurring.

[0174] That is, if in step S606, it is determined that the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1 are not met, then the microcomputer 510 selects the front wheel steering device 400 (front wheel steering actuator) and the rear wheel braking device 300 (rear wheel braking actuator) as the control objects of the vehicle slip angle control.

[0175] Next, microcomputer 510 proceeds to step S614 and determines, similarly to step S608 , whether the driver's steering angle θ is greater than threshold value θTH and steering angular velocity ω obtained by time-differentiating steering angle θ is greater than threshold value ωTH.

[0176] When the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH, the microcomputer 510 proceeds to step S615.

[0177] In step S615, the microcomputer 510 outputs a steering control signal for the front wheels based on the required lateral force of the front wheels of the vehicle slip angle control amount, and outputs a braking control signal for each rear wheel based on the required front and rear force of each rear wheel of the vehicle slip angle control amount.

[0178] On the other hand, when it is determined in step S614 that the conditions that the steering angle θ is greater than the threshold value θTH and the steering angular velocity ω is greater than the threshold value ωTH are not satisfied, the microcomputer 510 ends the routine without executing the vehicle slip angle control.

[0179] After executing the processing of step S609 , step S612 , and step S615 , the microcomputer 510 proceeds to step S616 to compare the vehicle speed VS obtained based on the output of the wheel speed sensor 106 with the threshold value VSTH.

[0180] Here, the threshold value VSTH is the vehicle speed VS which is the termination condition of the ESS.

[0181] When the vehicle speed VS is lower than the threshold value VSTH, the microcomputer 510 ends the vehicle slip angle control.

[0182] On the other hand, when the vehicle speed VS is equal to or higher than the threshold value VSTH and the ESS is continued, the microcomputer 510 proceeds to step S617.

[0183] In step S617 , the microcomputer 510 determines whether the distance D from the vehicle 100 to the obstacle ahead is greater than a threshold value DTH.

[0184] Here, when the distance D to the obstacle is greater than the threshold value DTH, the margin of the collision avoidance control is large, and the requirement for the accuracy of following the avoidance path is relatively low.

[0185] Therefore, when it is determined in step S617 that the distance D to the obstacle is greater than the threshold value DTH, the microcomputer 510 proceeds to step S607 and makes the vehicle slip angle β approach the reference angle βTH by controlling only the front wheel steering device 400 .

[0186] In other words, when the distance D to the obstacle is greater than the threshold value DTH, the microcomputer 510 selects only the front wheel steering device 400 as the control target of the vehicle slip angle control regardless of the conditions of the vehicle slip angle β and the vehicle slip angular velocity α.

[0187] On the other hand, when the distance D to the obstacle is equal to or smaller than the threshold value DTH, the margin of the collision avoidance control is small, and the vehicle slip angle β needs to be quickly brought close to the reference angle βTH to improve the followability to the avoidance path.

[0188] Therefore, when it is determined in step S617 that the distance D to the obstacle is equal to or smaller than the threshold value DTH, the microcomputer 510 proceeds to step S605 to select a control target based on the vehicle slip angle β and the vehicle slip angular velocity α.

[0189] Furthermore, the first threshold value βTH1 and the second threshold value βTH2 of the vehicle slip angle β and the threshold value αTH1 of the vehicle slip angular velocity α used by the microcomputer 510 in the process of selecting the control target are set as follows.

[0190] The first threshold βTH1 of the vehicle slip angle β and the threshold αTH1 of the vehicle slip angular velocity α depend on the path following control logic, for example, in the case of forward gaze control, they are affected by the forward gaze distance (forward gaze distance=forward gaze time / vehicle speed).

[0191] Therefore, the first threshold value βTH1 of the vehicle slip angle β and the threshold value αTH1 of the vehicle slip angular velocity α are adapted according to the path following control logic, for example, the set value of the forward gaze distance.

[0192] In addition, the second threshold value βTH2 of the vehicle slip angle β is affected by factors that affect the tire friction circle (in other words, the grip limit of the tire).

[0193] Therefore, the second threshold value β TH2 of the vehicle slip angle β is adapted according to factors affecting the tire friction circle.

[0194] Factors that affect the tire friction circle include, for example, ground load, tire type such as summer tires and winter tires, tire air pressure, temperature, tire wear, and road surface friction coefficient.

[0195] When changing the second threshold value βTH2 according to the vertical load, the microcomputer 510 estimates the vertical load information based on the output of the acceleration sensor 101 and the output of the gyro sensor 102 , and the second threshold value βTH2 can be increased as the vertical load increases.

[0196] In addition, in the case where the second threshold value βTH2 is changed according to the type of tire, the microcomputer 510 is able to obtain information on the tire type from a user of the vehicle 100, for example, and increase the second threshold value βTH2 when summer tires (in other words, standard tires) are installed on the vehicle 100 compared to when winter tires (e.g., studless tires) are installed on the vehicle 100.

[0197] When changing the second threshold βTH2 according to the tire pressure and temperature, the microcomputer 510 can obtain information on the tire pressure and temperature from a sensor, for example, and increase the second threshold βTH2 as the pressure increases or as the temperature increases.

[0198] In addition, when the second threshold value βTH2 is changed according to the tire wear, the microcomputer 510 can estimate the slip ratio of the tire based on the output of the acceleration sensor 101 and the output of the gyro sensor 102, and estimate the tire wear based on the slip ratio. The greater the tire wear, the larger the second threshold value βTH2.

[0199] Furthermore, when the second threshold value βTH2 is changed according to the friction coefficient of the road surface, the microcomputer 510 can, for example, estimate the slip ratio of the tire based on the output of the acceleration sensor 101 and the output of the gyro sensor 102, and estimate the friction coefficient of the road surface based on the slip ratio. The greater the friction coefficient of the road surface, the greater the second threshold value βTH2.

[0200] According to the collision avoidance assistance of the first embodiment, when executing the ESS to make the vehicle 100 follow the avoidance path, the microcomputer 510 performs steering control and braking control for reducing the vehicle slip angle β, thereby improving the followability of the avoidance path and improving the performance of collision avoidance and damage reduction.

[0201] Furthermore, in the vehicle slip angle control for reducing the vehicle slip angle β, the microcomputer 510 selects a control target based on information on the vehicle slip angle β and the vehicle slip angular velocity α.

[0202] Therefore, the microcomputer 510 can switch the control target in consideration of the tire force of each wheel and the limit of the tire force for obtaining the yaw moment required to reduce the vehicle slip angle β.

[0203] Therefore, the microcomputer 510 can effectively reduce the vehicle slip angle β, stably improve the accuracy of following the avoidance path, and can suppress the wear of the brake pads and ensure functional safety for a long period of time by selectively intervening the brake control according to the situation.

[0204] Fig. 9 is a state diagram showing the difference in recognition of the lateral offset amount depending on the presence or absence of the vehicle slip angle β. Fig. 9 The upper part of shows the state where an error occurs in the identification of the lateral offset due to the generation of the vehicle slip angle β. Fig. 9 The lower part of shows a state in which the recognition error of the lateral offset amount is eliminated as a result of the control to reduce the vehicle slip angle β.

[0205] When the lateral offset amount relative to the avoidance path is determined based on the front-rear direction of the vehicle 100, when the vehicle slip angle β is generated and the front-rear direction of the vehicle 100 does not match the vehicle speed vector, an error occurs in the recognition of the lateral offset amount. Fig. 9 In the case shown in the upper part of , by judging the lateral offset amount to be too small, the followability to the avoidance path is reduced.

[0206] At this time, through Fig. 9 In the example, a counterclockwise yaw moment is applied to the vehicle 100, such as Fig. 9 As shown in the lower part of , if the vehicle slip angle β is made close to zero, the front-rear direction of the vehicle 100 is consistent with the vehicle speed vector, and the recognition error of the lateral offset amount can be reduced.

[0207] Furthermore, by accurately recognizing the lateral deviation amount with respect to the avoidance path, the followability to the avoidance path is improved, and the performance of collision avoidance and damage reduction is improved.

[0208] Fig.10 It is a timing chart showing the correlation between the vehicle slip angle β and the following error with respect to the target path such as the avoidance path.

[0209] and, Fig.10 The upper part of shows a case where the vehicle slip angle β becomes smaller by implementing the control for reducing the vehicle slip angle β. Fig.10 The lower part of shows that the following error with respect to the target path is reduced as the vehicle slip angle β becomes smaller.

[0210] That is, the microcomputer 510 can accurately recognize the lateral deviation amount with respect to the avoidance path by executing the vehicle slip angle control for reducing the vehicle slip angle β, and can improve the followability with respect to the avoidance path.

[0211] Fig.11 An example of setting the lateral force and the longitudinal force in order to obtain the yaw moment required to bring the vehicle slip angle β close to the reference angle βTH is shown.

[0212] Fig.11 The vehicle slip angle control is shown in the case where a counterclockwise yaw moment is applied to the vehicle 100 , in other words, a yaw moment that causes the vehicle 100 to face the left side, so that the vehicle slip angle β approaches zero.

[0213] In this case, the lateral force generated by steering the front wheels to the left can be used to apply a yaw moment to the vehicle 100 that causes the vehicle 100 to be directed toward the left side, and by applying braking force to the left front and rear wheels of the left side of the left and right wheels of the vehicle 100, a yaw moment can also be applied to the vehicle 100 that causes the vehicle 100 to be directed toward the left side.

[0214] Therefore, in the above steps S607, S612 and S615, the microcomputer 510 sets the steering direction and the wheel to which the braking force is applied according to the direction in which the vehicle slip angle β is generated, and sets the steering angle and the front and rear force (braking force) according to the size of the vehicle slip angle β.

[0215] In addition, if Fig.11 As shown, by applying driving force to the side of the left and right wheels opposite to the side to which braking force is applied, for example, by applying a yaw moment to the vehicle 100 that causes the vehicle 100 to move toward the left, the vehicle 100 can also be given the yaw moment required to make the vehicle slip angle β approach the reference angle βTH.

[0216] That is, the microcomputer 510 may control the driving force of each wheel in addition to controlling the braking force of each wheel so as to bring the vehicle slip angle β close to the reference angle βTH.

[0217] [Second embodiment]

[0218] The following describes a second embodiment in which the microcomputer 510 selectively switches the control object in the vehicle slip angle control that makes the vehicle slip angle β approach the reference angle βTH to a steering actuator, or any one of the three: a braking actuator, a driving actuator, and a steering actuator.

[0219] Fig.12 1 is a block diagram showing a vehicle control system 200 that performs collision avoidance assistance (AEB and ESS) in the second embodiment.

[0220] In addition, Fig.12 In the vehicle control system 200 shown in FIG. Figure 1 The same elements of the vehicle control system 200 of the first embodiment are denoted by the same reference numerals, and detailed descriptions of blocks having the same functions are omitted.

[0221] Fig.12 The vehicle control system 200 is shown with Figure 1 The vehicle control system 200 of the first embodiment shown is different in that a drive device 310 is additionally provided for applying drive force to each of the four wheels to be controlled, and the control signal calculation unit 540 further outputs a control signal to the drive device 310 .

[0222] The drive device 310 includes an actuator that can electronically control the driving force of each wheel individually using an electrical signal.

[0223] The drive device 310 is a drive actuator that applies a drive force to each wheel among the brake drive actuators of each wheel, and the vehicle 100 including the drive device 310 is a so-called four-wheel drive vehicle.

[0224] In addition, the steering assistance request value calculation unit 520 is similar to the first embodiment (see Figure 3 ) has the same structure as the steering assist required value calculation unit 520, but the β angle minimization required value calculation unit 521 that constitutes the steering assist required value calculation unit 520 calculates the braking force of each wheel and the driving force of each wheel as the required front and rear forces in the vehicle slip angle control.

[0225] When the β angle minimization required value calculation unit 521 obtains the required front-rear force of each wheel for obtaining the yaw moment in the direction of reducing the vehicle slip angle β, for example, Fig.11 As shown, the required front and rear forces of each wheel are calculated so that a braking force is applied to one of the left and right wheels, and a driving force is applied to the other of the left and right wheels.

[0226] Fig.13 4 is a functional block diagram of the control signal calculation unit 540 in the second embodiment.

[0227] In addition, Fig.13 In the embodiment of the present invention, the details of the control signal calculation unit 540 are shown. Figure 5 The same elements are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0228] Fig.13 The control signal calculation unit 540 of the second embodiment shown obtains the signal of the required front and rear force of each wheel of the steering assistance amount (ESS amount) and the signal of the required lateral force of the front wheel of the steering assistance amount from the steering assistance required value calculation unit 520, and obtains the signal of the required front and rear force of each wheel of the braking assistance amount (AEB amount) from the braking assistance required value calculation unit 530.

[0229] The required front-rear force of the steering assistance amount output by the steering assistance required value calculation unit 520 indicates the required driving force when it is a positive value, and indicates the required braking force when it is a negative value.

[0230] The adding unit 541 obtains the required front-rear force signal of each wheel of the steering assist amount and the required front-rear force signal of each wheel of the braking assist amount, and outputs their added value as the required front-rear force signal of each wheel of the collision avoidance assist amount.

[0231] The first conversion unit 542 converts the signal of the required front and rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 into a braking and driving control signal for each wheel.

[0232] The sign determination unit 546 determines the sign of the required front-rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 , thereby determining whether the required front-rear force is a braking request or a driving request for each wheel.

[0233] The brake signal switching unit 547 obtains the brake drive control signal of each wheel from the first conversion unit 542 , and obtains a signal indicating a result of sign determination from the sign determination unit 546 .

[0234] Moreover, when the sign of the required front and rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 is positive and the required front and rear force of the collision avoidance assistance amount is the required driving force, the braking signal switching unit 547 sets the braking control signal to zero, that is, outputs it as a braking request without collision avoidance assistance amount.

[0235] On the other hand, when the sign of the required front and rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 is negative and the required front and rear force of the collision avoidance assistance amount is the required braking force, the brake signal switching unit 547 outputs the brake drive control signal output by the first conversion unit 542 as a brake control signal.

[0236] The drive signal switching unit 548 obtains the brake drive control signal of each wheel from the first conversion unit 542 , and obtains a signal indicating a result of sign determination from the sign determination unit 546 .

[0237] Moreover, when the sign of the required front and rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 is negative and the required front and rear force of the collision avoidance assistance amount is the required braking force, the drive signal switching unit 548 sets the drive control signal to zero, that is, outputs it as a drive request without collision avoidance assistance amount.

[0238] On the other hand, when the sign of the required front and rear force of each wheel of the collision avoidance assistance amount output by the addition unit 541 is positive and the required front and rear force of the collision avoidance assistance amount is the required driving force, the drive signal switching unit 548 outputs the braking drive control signal output by the first conversion unit 542 as the drive control signal.

[0239] That is, the sign discrimination unit 546, the brake signal switching unit 547 and the drive signal switching unit 548 output a brake control signal or a drive control signal for each wheel according to whether the required front and rear force of the collision avoidance assistance amount is a required braking force or a required driving force, which is obtained by adding the required front and rear force of the steering assistance amount and the required front and rear force of the brake assistance amount.

[0240] The second conversion unit 543 obtains the signal of the required lateral force of the front wheels of the steering assist amount, and converts the signal of the required lateral force of the front wheels of the steering assist amount into a steering control signal for the front wheels.

[0241] The comparison unit 544 acquires a vehicle speed signal based on the output of the wheel speed sensor 106, compares the acquired vehicle speed signal with a threshold value, and outputs a switching signal for switching between output and stop of the requested value of the collision avoidance assistance amount.

[0242] The switching unit 545-2 obtains the braking control signal of each wheel output by the braking signal switching unit 547, the driving control signal of each wheel output by the driving signal switching unit 548, the steering control signal of the front wheel output by the second conversion unit 543, and the switching signal output by the comparison unit 544.

[0243] Furthermore, based on the switching signal outputted from the comparison unit 544, the switching unit 545-2 switches the output of the braking control signal, the driving control signal, and the steering control signal to the subsequent stage (the braking device 300, the driving device 310, and the front wheel steering device 400) and stops.

[0244] Here, the structure is such that when the vehicle speed is low and below a threshold, the output of the braking control signal, the driving control signal, and the steering control signal to the subsequent stage is stopped, and when the vehicle speed exceeds the threshold, the braking control signal, the driving control signal, and the steering control signal are output to the subsequent stage.

[0245] That is, when the vehicle speed is sufficiently low, the effectiveness of the collision avoidance assistance becomes low, so the control signal calculation unit 540 stops the braking control, the driving control, and the steering control for the collision avoidance assistance.

[0246] Fig.14 - Fig.16 The flowchart shows the process of selecting a control object by the control device selection unit 560 and the process of vehicle slip angle control by the β angle minimization required value calculation unit 521 in the second embodiment.

[0247] In the second embodiment, the β angle minimization required value calculation unit 521 obtains a required braking force or a required driving force for each wheel as a required front-rear force for obtaining a yaw moment required to make the vehicle body slip angle β equal to the reference angle βTH.

[0248] On the other hand, the process of selecting a control target and the like performed by the control device selection unit 560 in the second embodiment are the same as those in the first embodiment.

[0249] therefore, Fig.14 - Fig.16 The flowchart of FIG. 1 only has the processing contents in step S612-2 and step S615-2 different from those in FIG. 11 which show the processing contents of the first embodiment. Figure 6 - Figure 8 The flow chart is different.

[0250] Therefore, for each step other than step S612-2 and step S615-2, the same as Figure 6 - Figure 8 The same steps as in the flowchart are numbered and detailed descriptions are omitted.

[0251] If the microcomputer 510 determines in step S606 that the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1, the process proceeds to step S610.

[0252] Then, in step S610, the microcomputer 510 calculates the required lateral force of the front wheels and the required front and rear forces (required braking force, required driving force) of each wheel for obtaining the yaw moment required to make the vehicle slip angle β close to the reference angle βTH based on the deviation Δβ between the vehicle slip angle β and the reference angle βTH.

[0253] Next, when the microcomputer 510 determines in step S611 that the driver's steering operation as a trigger for starting the operation of the ESS has been performed, the process proceeds to step S612 - 2 .

[0254] In step S612-2, the microcomputer 510 outputs the front wheel steering control signal to the front wheel steering device 400 based on the required lateral force of the front wheel calculated in step S610. In addition, based on the required front and rear forces (required braking force, required driving force) of each wheel calculated in step S610, the microcomputer 510 outputs the braking control signal of each wheel to the braking device 300 and outputs the driving control signal of each wheel to the driving device 310.

[0255] If the microcomputer 510 determines in step S606 that the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1, the process proceeds to step S613.

[0256] Then, in step S613, the microcomputer 510 calculates the required lateral force of the front wheels and the required front and rear forces (required braking force, required driving force) of each rear wheel for obtaining the yaw moment required to make the vehicle slip angle β close to the reference angle βTH based on the deviation Δβ between the vehicle slip angle β and the reference angle βTH.

[0257] Next, when the microcomputer 510 determines in step S614 that the driver's steering operation as a trigger for starting the operation of the ESS has been performed, the process proceeds to step S615 - 2 .

[0258] In step S615-2, the microcomputer 510 outputs the front wheel steering control signal to the front wheel steering device 400 based on the required lateral force of the front wheel calculated in step S613, and outputs the braking control signal of each rear wheel to the braking device 300 and the driving control signal of each rear wheel to the driving device 310 based on the required front and rear forces (required braking force, required driving force) of each rear wheel calculated in step S613.

[0259] According to the second embodiment, when both the steering actuator and the brake drive actuator are selected as the control targets of the vehicle slip angle control, both the brake actuator and the drive actuator are selected among the brake drive actuators.

[0260] Therefore, compared with the first embodiment in which only the brake actuator is selected among the brake drive actuators, it is easier to ensure the yaw moment required to bring the vehicle slip angle β close to the predetermined reference angle βTH, and the accuracy of following the avoidance path can be stably maintained.

[0261] [Third Embodiment]

[0262] However, when the vehicle 100 includes the front wheel steering device 400 and the rear wheel steering device, the control target in the vehicle slip angle control for obtaining the yaw moment required to bring the vehicle slip angle β close to the reference angle βTH may include the rear wheel steering device.

[0263] Hereinafter, a third embodiment in which the control target of the vehicle slip angle control includes the rear wheel steering device will be described.

[0264] Fig.17 This is a block diagram showing a vehicle control system 200 that performs collision avoidance assistance (AEB and ESS) in the third embodiment.

[0265] In addition, Fig.17 In the vehicle control system 200 shown in FIG. Fig.12 The same elements of the vehicle control system 200 are denoted by the same reference numerals, and detailed descriptions of blocks having the same functions are omitted.

[0266] Fig.17 The vehicle control system 200 is shown with Fig.12 The vehicle control system 200 of the second embodiment shown is different in that a rear-wheel steering device 410 is additionally provided as a control target, and the control signal calculation unit 540 further outputs a control signal to the rear-wheel steering device 410 .

[0267] The rear wheel steering device 410 includes an actuator that can electronically control the steering angle of the rear wheels using an electrical signal.

[0268] In the present application, the steering actuator includes a front wheel steering actuator and a rear wheel steering actuator, the front wheel steering device 400 is equivalent to the front wheel steering actuator in the steering actuator, and the rear wheel steering device 410 is equivalent to the rear wheel steering actuator in the steering actuator.

[0269] Furthermore, the vehicle 100 of the third embodiment includes both the front wheel steering device 400 as a front wheel steering actuator and the rear wheel steering device 410 as a rear wheel steering actuator.

[0270] Fig.18 4 is a functional block diagram of the control signal calculation unit 540 in the third embodiment.

[0271] In addition, Fig.18 In the embodiment of the present invention, the control signal calculation unit 540 of the second embodiment is described in detail. Fig.13 The same elements are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0272] Fig.18 The control signal calculation unit 540 of the third embodiment shown obtains the signal of the required front and rear force of each wheel (the required braking force and the required driving force of each wheel) of the steering assistance amount and the signal of the required lateral force of each wheel (the required lateral force of the front wheel and the required lateral force of the rear wheel) of the steering assistance amount from the steering assistance required value calculation unit 520, and obtains the signal of the required front and rear force (required braking force) of each wheel of the braking assistance amount from the braking assistance required value calculation unit 530.

[0273] Then, the second conversion unit 543-3 converts the signal of the required lateral force of each wheel (front and rear wheels) of the steering assist amount into a steering control signal for the front wheels and a steering control signal for the rear wheels.

[0274] When the vehicle speed is low or lower than a threshold, the switching unit 545 - 3 sets the braking and driving control signals of each wheel and the steering control signals of the front and rear wheels to zero and outputs them, thereby stopping the braking and driving control and steering control for AEB and ESS.

[0275] When the vehicle speed exceeds a threshold value, the switching unit 545 - 3 directly outputs the braking and driving control signals of each wheel and the steering control signals of the front and rear wheels to the subsequent stage, thereby activating the AEB and ESS.

[0276] Moreover, the control signal calculation unit 540 outputs the braking control signal of each wheel to the braking device 300, outputs the driving control signal of each wheel to the driving device 310, outputs the steering control signal of the front wheel to the front wheel steering device 400, and further outputs the steering control signal of the rear wheel to the rear wheel steering device 410.

[0277] Fig.19 - Fig. 20 The flowchart shows the process of selecting a control object by the control device selection unit 560 and the process of vehicle slip angle control by the β angle minimization required value calculation unit 521 in the third embodiment.

[0278] In the third embodiment, the microcomputer 510 sets the following conditions as selection conditions for the control object in the vehicle slip angle control: the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2 (βTH2>βTH1>0), and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1.

[0279] Moreover, based on whether the above-mentioned selection conditions are met, the microcomputer 510 selectively switches the control object in the vehicle slip angle control to both the front wheel steering device 400 and the rear wheel steering device 410 (in other words, only the steering actuator), or to any one of the four of the front wheel steering device 400, the rear wheel steering device 410, the braking device 300 and the driving device 310 (in other words, both the steering actuator and the braking drive actuator).

[0280] Microcomputer 510 Fig.19 - Fig. 20 In steps S701 to S704 of the flowchart, the same processing as steps S601 to S604 described above is performed.

[0281] Then, in step S705 , the microcomputer 510 determines whether the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 , and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1 .

[0282] If the microcomputer 510 determines in step S705 that the condition is not satisfied, the process proceeds to step S706.

[0283] In step S706, microcomputer 510 calculates required lateral forces of the front wheels and rear wheels for obtaining a yaw moment required to bring vehicle slip angle β close to reference angle βTH based on deviation Δβ between vehicle slip angle β and reference angle βTH.

[0284] Next, in step S707 , the microcomputer 510 determines whether the steering angle θ of the front wheels by the driver is larger than a threshold value θTH and the steering angular velocity ω is larger than a threshold value ωTH.

[0285] Then, when the operating conditions of the ESS are satisfied, that is, the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH, the microcomputer 510 proceeds to step S708 .

[0286] In step S708, the microcomputer 510 outputs a front wheel steering control signal to the front wheel steering device 400 based on the required lateral force of the front wheel, and outputs a rear wheel steering control signal to the rear wheel steering device 410 based on the required lateral force of the rear wheel.

[0287] That is, when the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1 are not met, the microcomputer 510 selects the front wheel steering device 400 and the rear wheel steering device 410 (in other words, the steering actuator including the front wheel steering actuator and the rear wheel steering actuator) as the control objects of the vehicle slip angle control.

[0288] When the following conditions are not met: the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1, it is estimated that the yaw moment required to make the vehicle slip angle β approach the specified reference angle βTH can be generated only by the tire lateral force of each wheel based on the front wheel steering control and the rear wheel steering control, or the tire lateral force is saturated and there is no margin for generating tire fore-and-aft force.

[0289] Therefore, when the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1 are not met, the microcomputer 510 only selects the steering actuator including the front wheel steering device 400 and the rear wheel steering device 410 as the control object of the vehicle slip angle control.

[0290] On the other hand, if the microcomputer 510 determines in step S705 that the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1, the process proceeds to step S709.

[0291] In step S709, the microcomputer 510 calculates the required lateral force of the front wheels, the required lateral force of the rear wheels, and the required front and rear forces (required braking force, required driving force) of each wheel for obtaining the yaw moment required to make the vehicle slip angle β close to the reference angle βTH based on the deviation Δβ between the vehicle slip angle β and the reference angle βTH.

[0292] Next, the microcomputer 510 proceeds to step S710 and determines whether the conditions that the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH are satisfied, similarly to step S707 .

[0293] Then, when the operating conditions of the ESS are satisfied, that is, the steering angle θ is larger than the threshold value θTH and the steering angular velocity ω is larger than the threshold value ωTH, the microcomputer 510 proceeds to step S711 .

[0294] In step S711, the microcomputer 510 outputs the front wheel steering control signal to the front wheel steering device 400 based on the required lateral force of the front wheel, and outputs the rear wheel steering control signal to the rear wheel steering device 410 based on the required lateral force of the rear wheel. Furthermore, based on the required braking force of each wheel, the microcomputer 510 outputs the braking control signal of each wheel to the braking device 300, and based on the required driving force of each wheel, the microcomputer 510 outputs the driving control signal of each wheel to the driving device 310.

[0295] Furthermore, after the processing in step S708 or step S711 , the microcomputer 510 proceeds to step S712 to compare the vehicle speed VS with the threshold value VSTH.

[0296] Then, the microcomputer 510 terminates the vehicle slip angle control when the vehicle speed VS is lower than the threshold value VSTH, and proceeds to step S713 when the vehicle speed VS is higher than the threshold value VSTH.

[0297] In step S713, microcomputer 510 determines whether distance D from vehicle 100 to the front obstacle is greater than threshold value DTH.

[0298] If the microcomputer 510 determines in step S713 that the distance D to the obstacle is greater than the threshold DTH, the process proceeds to step S706 and controls the vehicle slip angle β to approach the reference angle βTH through the steering control of the front wheel steering device 400 and the rear wheel steering device 410.

[0299] On the other hand, when the distance D to the obstacle is equal to or smaller than the threshold value DTH, the microcomputer 510 proceeds to step S705 and selects a control target based on the vehicle slip angle β and the vehicle slip angular velocity α.

[0300] In the above-mentioned third embodiment, the microcomputer 510 selects whether to set the control object in the vehicle slip angle control to only the steering actuator including the front wheel steering device 400 and the rear wheel steering device 410, or to set it to both the steering actuator and the braking drive actuator including the braking device 300 and the driving device 310, depending on whether the following conditions are met: the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1.

[0301] Moreover, according to the third embodiment, the objects of the steering control in the vehicle slip angle control are set to both the front wheel steering device 400 and the rear wheel steering device 410, so that the range in which the vehicle slip angle control can be implemented only by steering control can be expanded, and the situation in which the behavior of the vehicle 100 becomes unstable can be suppressed.

[0302] [Fourth Embodiment]

[0303] Furthermore, the microcomputer 510 can predict the future vehicle slip angle β and select a control target for the vehicle slip angle control based on the predicted vehicle slip angle βes.

[0304] Hereinafter, a fourth embodiment for selecting a control target for vehicle slip angle control based on the estimated vehicle slip angle βes will be described.

[0305] The fourth embodiment is different from the first embodiment in that the process of selecting a control target for the vehicle slip angle control in the first embodiment is performed based on an estimated vehicle slip angle βes instead of the vehicle slip angle β.

[0306] Fig.21 1 is a block diagram showing a vehicle control system 200 that performs collision avoidance assistance (AEB and ESS) in the fourth embodiment.

[0307] In addition, Fig.21 In the vehicle control system 200 shown in FIG. Figure 1 The same elements of the vehicle control system 200 of the first embodiment are denoted by the same reference numerals, and detailed descriptions of blocks having the same functions are omitted.

[0308] Fig.21 The vehicle control system 200 shown in the figure is different from the vehicle control system 200 in that it includes a vehicle slip angle prediction unit 570. Figure 1 The vehicle control system 200 of the first embodiment shown is different.

[0309] The vehicle slip angle prediction unit 570 obtains information on the azimuth angle of the avoidance path from the steering assistance request value calculation unit 520 , and outputs information on the predicted vehicle slip angle βes to the control device selection unit 560 .

[0310] Here, the vehicle slip angle prediction unit 570 obtains a predicted vehicle slip angle βes as the future vehicle slip angle β based on the time rate of change of the azimuth angle of the avoidance path.

[0311] Fig. 22 - Fig.24 The flowchart shows the process of selecting a control object by the control device selection unit 560 and the process of vehicle slip angle control by the β angle minimization required value calculation unit 521 in the fourth embodiment.

[0312] Fig. 22 - Fig.24 The flowchart of the first embodiment is Figure 6 - Figure 8 The flowchart is different in that a step S604-4 is added for calculating the predicted vehicle slip angle βes and the predicted vehicle slip angular velocity αes. Furthermore, in steps S605-4 and S606-4, the first threshold βTH1, the second threshold βTH2 and the predicted vehicle slip angle βes are compared, and the threshold αTH1 and the predicted vehicle slip angular velocity αes are compared.

[0313] In step S604 , the microcomputer 510 obtains the vehicle slip angle β and the vehicle slip angular velocity α at the current moment, and then proceeds to step S604 - 2 .

[0314] In step S604-2, the microcomputer 510 calculates the time change rate of the azimuth angle of the avoidance path, calculates the predicted vehicle slip angle βes as the future vehicle slip angle β based on the time change rate of the azimuth angle of the avoidance path, and further calculates the predicted vehicle slip angle βes by time differentiation to calculate the predicted vehicle slip angular velocity αes.

[0315] Then, in step S605-4, the microcomputer 510 determines whether the absolute value of the predicted vehicle slip angle βes is smaller than the first threshold βTH1 and the absolute value of the predicted vehicle slip angular velocity αes is smaller than the threshold αTH1.

[0316] Furthermore, in step S606-4, the microcomputer 510 determines whether the absolute value of the predicted vehicle slip angle βes is greater than the first threshold βTH1 and less than the second threshold βTH2, and whether the absolute value of the predicted vehicle slip angular velocity αes is greater than the threshold αTH1.

[0317] That is, in the fourth embodiment, the microcomputer 510 selectively switches the control target of the vehicle slip angle control based on the future vehicle slip angle βes and vehicle slip angular velocity αes instead of the current vehicle slip angle β and vehicle slip angular velocity α.

[0318] According to the fourth embodiment, since the control object of the vehicle slip angle control is switched based on the predicted vehicle slip angle βes predicted to occur in the future, the change in the vehicle slip angle β can be predicted (predicted) in advance and switched to an appropriate control object in advance, and the response delay of the vehicle slip angle control can be suppressed.

[0319] The technical concepts described in the above embodiments can be used in combination as appropriate unless there is any contradiction.

[0320] Furthermore, although the contents of the present invention have been specifically described with reference to the preferred embodiments, it is apparent that a person skilled in the art can adopt various modified forms based on the basic technical idea and teaching of the present invention.

[0321] In the above embodiment, in collision avoidance assistance based on a combination of AEB and ESS, control for reducing the vehicle slip angle β is applied as control for improving the followability of the avoidance path generated by the driver's steering operation as a trigger. However, collision avoidance assistance is not limited to the combination of AEB and ESS.

[0322] For example, when executing control to make the vehicle 100 follow the avoidance path automatically generated based on information from the environment recognition sensor 105 , the microcomputer 510 can execute vehicle slip angle control to reduce the vehicle slip angle β.

[0323] Furthermore, the microcomputer 510 can switch from a setting in which only the steering actuator is used as the control target in the vehicle slip angle control for bringing the vehicle slip angle β close to the reference angle βTH.

[0324] For example, when the vehicle slip angle β is less than the first threshold value βTH1, the microcomputer 510 can set the control object to only the steering actuator; when the vehicle slip angle β is greater than the first threshold value βTH1 and greater than the second threshold value βTH2, the microcomputer 510 can set the control object to both the steering actuator and the brake drive actuator; when the vehicle slip angle β is greater than the second threshold value βTH2, the microcomputer 510 can set the control object to only the steering actuator, or both the steering actuator and the rear wheel brake drive actuator.

[0325] That is, microcomputer 510 can switch the control target in stages according to the increase in vehicle slip angle β.

[0326] In addition, when the control object of the vehicle slip angle control is switched in two ways based on the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1, as in the third embodiment, the microcomputer 510 can set the control object to an actuator different from that in the third embodiment.

[0327] For example, when the conditions that the absolute value of the vehicle slip angle β is greater than the first threshold βTH1 and less than the second threshold βTH2 and the absolute value of the vehicle slip angular velocity α is greater than the threshold αTH1 are not satisfied, the microcomputer 510 can control only the front wheel steering device 400.

[0328] In addition, when the absolute value of the vehicle slip angle β is greater than the first threshold value βTH1 and less than the second threshold value βTH2, and the absolute value of the vehicle slip angular velocity α is greater than the threshold value αTH1, the microcomputer 510 can be set to both the front wheel steering device 400 and the braking device 300, or to the front wheel steering device 400 and the rear wheel brake drive device.

[0329] In addition, Fig.14 - Fig.16 In the switching process of the control object of the second embodiment shown in the flowchart of Fig.19 - Fig. 20 In the switching process of the control object of the third embodiment shown in the flowchart, as in the fourth embodiment, the microcomputer 510 can compare the predicted vehicle slip angle βes with the first threshold value βTH1 and the second threshold value βTH2 instead of the vehicle slip angle β, and can compare the predicted vehicle slip angular velocity αes with the threshold value αTH1 instead of the vehicle slip angular velocity α.

[0330] Furthermore, when the vehicle slip angle β is lower than a set value, the microcomputer 510 can stop the vehicle slip angle control.

[0331] Furthermore, microcomputer 510 can selectively switch the control target in vehicle slip angle control for bringing vehicle slip angle β close to reference angle βTH based on physical quantities caused by tire force of vehicle 100 such as tire slip angle and yaw rate.

[0332] In the second embodiment, when the vehicle 100 is a rear-wheel drive vehicle and the drive device 310 applies driving force only to the rear wheels, the microcomputer 510 may Fig.15 In step S612-2, a drive control signal for the rear wheels is output.

[0333] In the second embodiment, when the vehicle 100 is a front-wheel drive vehicle and the drive device 310 applies driving force only to the front wheels, the microcomputer 510 can be configured to Fig.15 Step S612-2 and Fig.16 In step S615-2, the driving force control of each wheel is not performed.

[0334] Description of Reference Numerals

[0335] 100…Vehicle; 200…Vehicle control system; 300…Braking device (brake drive actuator, brake actuator); 400…Front wheel steering device (steering steering actuator); 500…Vehicle control device; 510…Microcomputer (control unit, control unit); 520…Steering steering assistance requirement value calculation unit; 530…Braking assistance requirement value calculation unit; 540…Control signal calculation unit; 550…Vehicle slip angle calculation unit; 560…Control device selection unit; β…Vehicle slip angle (first angle).

Claims

1. A vehicle control device, provided in a vehicle, the vehicle comprising a brake drive actuator for applying a brake drive force to a wheel and a steering actuator for steering the wheel, wherein: The vehicle control device includes a control unit Obtaining a first angle formed by the orientation of the vehicle and the traveling direction of the vehicle, obtaining an avoidance path for avoiding an object located in front of the vehicle, When executing the path following control for causing the vehicle to follow the avoidance path, executing the first angle control for bringing the first angle close to a predetermined reference angle, Based on a physical quantity caused by a tire force of the vehicle, a control target of the first angle control is selectively switched to the steering actuator, or to either the brake drive actuator or the steering actuator.

2. The vehicle control device according to claim 1, wherein: The control unit acquires a physical quantity related to the first angle as a physical quantity caused by a tire force of the vehicle.

3. The vehicle control device according to claim 2, wherein: The control unit acquires at least one of the first angle or an angular velocity of the first angle as a physical quantity related to the first angle.

4. The vehicle control device according to claim 3, wherein: The control unit The first angle is greater than a prescribed first angle threshold, the first angle is less than a prescribed second angle threshold that is greater than the first angle threshold, and the angular velocity of the first angle is less than a prescribed angle threshold as selection conditions for selecting a control object for the first angle control, When the selection condition is satisfied, both the brake drive actuator and the steering actuator are selected as the control objects of the first angle control. When the selection condition is not satisfied, the direction steering actuator is selected as the control object of the first angle control.

5. The vehicle control device according to claim 4, wherein: The control unit acquires the first angle and the angular velocity of the first angle when the speed of the vehicle in the front-rear direction is greater than a predetermined front-rear speed threshold.

6. The vehicle control device according to claim 1, wherein: The control unit executes the first angle control when a steering angle based on an operation by a driver of the vehicle is greater than a predetermined steering angle threshold and an angular velocity of the steering angle is greater than a predetermined steering angular velocity threshold.

7. The vehicle control device according to claim 1, wherein: After the first angle control is started, when the speed of the vehicle becomes lower than a predetermined vehicle speed threshold, the control unit ends the first angle control.

8. The vehicle control device according to claim 1, wherein: The control unit selectively switches the control object of the first angle control to the steering actuator, or to either one of the braking actuator and the steering actuator in the brake-drive actuator that applies braking force to the wheel, based on a physical quantity caused by a tire force of the vehicle.

9. The vehicle control device according to claim 1, wherein: The control unit selectively switches the control object of the first angle control to the steering actuator, or any one of the three of the braking actuator that applies braking force to the wheel and the driving actuator that applies driving force to the wheel and the steering actuator based on the physical quantity caused by the tire force of the vehicle.

10. The vehicle control device according to claim 1, wherein: The reference angle is zero.

11. A vehicle control method, executed by a control unit provided in a vehicle, wherein the vehicle has a braking drive actuator for applying braking drive force to wheels and a steering actuator for steering the wheels, wherein: Obtaining a first angle formed by the orientation of the vehicle and the traveling direction of the vehicle, obtaining an avoidance path for avoiding an object located in front of the vehicle, When executing the path following control for causing the vehicle to follow the avoidance path, executing the first angle control for bringing the first angle close to a predetermined reference angle, Based on a physical quantity caused by a tire force of the vehicle, a control target of the first angle control is selectively switched to the steering actuator, or to either the brake drive actuator or the steering actuator.

12. A vehicle control system comprising: A brake drive actuator applies a brake drive force to the wheels of the vehicle; a steering actuator for steering the wheel; and A control unit is provided in the vehicle, wherein the control unit Obtaining a first angle formed by the orientation of the vehicle and the traveling direction of the vehicle, obtaining an avoidance path for avoiding an object located in front of the vehicle, When executing the path following control for causing the vehicle to follow the avoidance path, executing the first angle control for bringing the first angle close to a predetermined reference angle, Based on a physical quantity caused by a tire force of the vehicle, a control target of the first angle control is selectively switched to the steering actuator, or to either the brake drive actuator or the steering actuator.

Images