WO2014016947A1

WO2014016947A1 - Vehicle control system and control unit

Info

Publication number: WO2014016947A1
Application number: PCT/JP2012/069030
Authority: WO
Inventors: 鈴村　将人
Original assignee: トヨタ自動車株式会社
Priority date: 2012-07-26
Filing date: 2012-07-26
Publication date: 2014-01-30

Abstract

This vehicle control system (1) is characterized by being equipped with: steering units (5) capable of steering front wheels (3F) and rear wheels (3R) of a vehicle (2); detection units (13) for detecting a condition ahead in the direction the vehicle (2) is traveling; and a control unit (7) which is capable of controlling the steering units (5) according to body slip angle characteristics of the vehicle (2) and executing automatic driving control by controlling the vehicle (2) on the basis of a detection result of the detection units (13) and which changes the body slip angle characteristics of the vehicle (2) depending on whether or not the automatic driving control is being executed. Therefore, with the vehicle control system (1) and the control unit (7), the automatic driving control of the vehicle (2) for which the front wheels (3F) and the rear wheels (3R) are steerable can be properly executed.

Description

Vehicle control system and control device

The present invention relates to a vehicle control system and a control device.

As a conventional vehicle control system and control device mounted on a vehicle, for example, in Patent Document 1, a steering wheel is given according to a traveling state of the vehicle and a front wheel that is given a steering angle by steering a steering wheel. A control device for a front and rear wheel steering vehicle having rear wheels is disclosed. This front / rear wheel steering vehicle control device controls the rear wheel steering angle based on the deviation between the standard yaw rate corresponding to the steering angle of the steering wheel and the actual yaw rate acting on the vehicle, thereby turning the vehicle's turning motility and disturbance. The balance with restraint is aimed at.

JP-A-6-171540

By the way, the control device for the front and rear wheel steering vehicle described in Patent Document 1 described above is, for example, in terms of automatic driving control for controlling the vehicle based on the detection result of the detection device that detects the situation on the front side in the traveling direction of the vehicle. There is room for further improvement.

The present invention has been made in view of the above circumstances, and provides a vehicle control system and a control device capable of appropriately executing automatic driving control in a vehicle in which front wheels and rear wheels are steering wheels. Objective.

In order to achieve the above object, a vehicle control system according to the present invention includes a steering device capable of steering a front wheel and a rear wheel of a vehicle, a detection device that detects a situation on the front side in the traveling direction of the vehicle, and the vehicle The steering device can be controlled in accordance with the vehicle body slip angle characteristic, and the vehicle can be controlled based on the detection result of the detection device to execute automatic driving control. And a control device that changes the vehicle body slip angle characteristic of the vehicle.

In the vehicle control system, the control device changes the vehicle body slip angle characteristic in the high speed range where the vehicle speed of the vehicle is equal to or higher than a predetermined vehicle speed set in advance according to whether or not the automatic driving control is executed. Can be.

In the vehicle control system, the control device may change the vehicle body slip angle characteristic of the vehicle based on at least one of the vehicle speed of the vehicle and the turning radius of the vehicle. .

In the vehicle control system, the control device changes the vehicle body slip angle characteristic of the vehicle based on a target locus that is a target locus of the vehicle generated based on a detection result of the detection device. Can be.

Further, in the vehicle control system, the control device has a relatively large vehicle body slip angle when the automatic driving control is being executed, compared to when the automatic driving control is not being executed. Thus, the vehicle body slip angle characteristic of the vehicle can be changed.

In the vehicle control system, when the automatic operation control is being performed, the control device is configured such that the vehicle body slip angle of the vehicle is relatively increased as the vehicle speed of the vehicle is relatively increased. The vehicle body slip angle characteristic can be changed.

In the vehicle control system, when the automatic driving control is being performed, the control device is configured so that the vehicle body slip angle is relatively increased as the turning radius of the vehicle is relatively decreased. The vehicle body slip angle characteristic of the vehicle can be changed.

Further, in the vehicle control system, the control device switches from a state in which the automatic driving control is performed to a state in which the automatic driving control is not performed, and from a state in which the automatic driving control is not performed. When switching to a state in which automatic driving control is executed, the rate of change of the steering angle of the front wheels and the rear wheels can be limited.

Further, in the vehicle control system, the control device may change the vehicle body slip angle characteristic of the vehicle according to a contact prediction between the vehicle and an object around the vehicle.

Further, in the vehicle control system, the control device is configured so that the vehicle body of the vehicle can be used even when the contact between the vehicle and an object around the vehicle is predicted, or when the automatic driving control is being executed. The vehicle body slip angle characteristic of the vehicle may be changed so that the slip angle is equivalent to that when the automatic operation control is not executed.

In the vehicle control system, the vehicle body slip angle characteristic of the vehicle is set based on a slip angle gain corresponding to a ratio between the vehicle body slip angle of the vehicle and the steering wheel steering angle of the vehicle, and the control device includes: The vehicle body slip angle characteristic of the vehicle can be changed by changing the slip angle gain.

In order to achieve the above object, a control device according to the present invention controls the vehicle based on a detection result by a detection device that detects a situation on the front side in the traveling direction of the vehicle in which front wheels and rear wheels are steering wheels. Automatic driving control can be executed, and the vehicle body slip angle characteristic of the vehicle is changed according to whether or not the automatic driving control is executed.

The vehicle control system and the control device according to the present invention have an effect that it is possible to appropriately execute automatic driving control in a vehicle in which front wheels and rear wheels are steering wheels.

FIG. 1 is a schematic configuration diagram of a vehicle to which the vehicle control system according to the first embodiment is applied. FIG. 2 is a block diagram illustrating a schematic configuration example of the ECU of the vehicle control system according to the first embodiment. FIG. 3 is a schematic diagram illustrating an example of a detection range of the front detection device in the vehicle control system according to the first embodiment. FIG. 4 is a diagram illustrating an example of a first vehicle body slip angle gain map in the vehicle control system according to the first embodiment. FIG. 5 is a diagram illustrating an example of a second vehicle body slip angle gain map in the vehicle control system according to the first embodiment. FIG. 6 is a flowchart illustrating an example of control by the ECU of the vehicle control system according to the first embodiment. FIG. 7 is a flowchart illustrating an example of control by the ECU of the vehicle control system according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram of a vehicle to which the vehicle control system according to the first embodiment is applied, FIG. 2 is a block diagram illustrating a schematic configuration example of an ECU of the vehicle control system according to the first embodiment, and FIG. FIG. 4 is a schematic diagram for explaining an example of a detection range of the front detection device in the vehicle control system according to the first embodiment. FIG. 4 is a diagram showing an example of a first vehicle body slip angle gain map in the vehicle control system according to the first embodiment. 5 is a diagram illustrating an example of a second vehicle body slip angle gain map in the vehicle control system according to the first embodiment, and FIG. 6 is a flowchart illustrating an example of control by the ECU of the vehicle control system according to the first embodiment. .

The vehicle control system 1 of this embodiment is mounted on a vehicle 2 as shown in FIG. Here, the vehicle 2 moves forward in the arrow Y direction in FIG. The direction in which the vehicle 2 moves forward is the direction from the driver seat where the driver of the vehicle 2 sits toward the steering wheel. The left-right distinction is based on the direction in which the vehicle 2 moves forward (the direction of the arrow Y in FIG. 1). That is, “left” refers to the left side in the direction in which the vehicle 2 moves forward, and “right” refers to the right side in the direction in which the vehicle 2 moves forward. Further, before and after the vehicle 2, the direction in which the vehicle 2 moves forward is defined as the front, and the direction in which the vehicle 2 moves backward, that is, the direction opposite to the direction in which the vehicle 2 moves forward is defined as the rear.

The vehicle 2 includes, as wheels 3, a left front wheel (left front wheel 3) 3FL, a right front wheel (right front wheel 3) 3FR, a left rear wheel (left rear wheel 3) 3RL, and a right rear wheel (right rear side). Wheel 3) with 3RR. In the following description, the left front wheel 3FL, the right front wheel 3FR, the left rear wheel 3RL, and the right rear wheel 3RR may be simply referred to as “wheel 3” when there is no need to describe them separately. Further, in the following description, there is a case where the left front wheel 3FL and the right front wheel 3FR are simply referred to as “front wheel 3F” when it is not necessary to describe them separately. Similarly, in the following description, the left rear wheel 3RL and the right rear wheel 3RR may be simply referred to as “rear wheel 3R” when there is no need to describe them separately.

The vehicle control system 1 is a driving support system equipped with a steering device 6 or the like that can steer the front wheels 3F and the rear wheels 3R of the vehicle 2. The vehicle control system 1 typically includes a vehicle 2 including a steering device 6 that is a four-wheel steering mechanism including a front wheel steering device 9 and a rear wheel steering device 10. The posture is arbitrarily controlled.

Specifically, as shown in FIG. 1, the vehicle control system 1 includes a drive device 4, a braking device 5, a steering device 6, and an ECU (Electronic Control Unit) 7 as a control device.

The driving device 4 constitutes a power train including a power source 4a, a torque converter 4b, a transmission 4c, and the like in the vehicle 2, and rotationally drives the wheels 3 serving as driving wheels. The power source 4a generates rotational power that causes the vehicle 2 to travel, and is a power source for traveling such as an internal combustion engine (engine) or an electric motor (rotary machine). The vehicle 2 may be any of a hybrid vehicle having both an internal combustion engine and an electric motor as a driving power source, a combined vehicle having an internal combustion engine but no electric motor, and an EV vehicle having an electric motor and no internal combustion engine. The vehicle of the form may be sufficient. The driving device 4 transmits the power generated by the power source 4a from the power source 4a to the wheels 3 (for example, the left rear wheel 3RL and the right rear wheel 3RR as driving wheels) via the torque converter 4b, the transmission 4c, and the like. To do. The drive device 4 is electrically connected to the ECU 7 and controlled by the ECU 7. In the vehicle 2, the driving device 4 generates power (torque) according to the operation (accelerator operation) of the accelerator pedal 8 a by the driver, and this power is transmitted to the wheels 3 to generate driving force on the wheels 3. As a result, the vehicle 2 can move forward or backward by the driving force generated by the driving device 4. In addition, the vehicle 2 generates a braking force on the wheels 3 by the operation of the braking device 5 according to the operation (braking operation) of the brake pedal 8b by the driver. Thereby, the vehicle 2 can be decelerated and stopped by the braking force generated by the braking device 5.

The steering device 6 is capable of steering the front wheels 3F and the rear wheels 3R of the vehicle 2, and includes a front wheel steering device 9 and a rear wheel steering device 10 here. The front wheel steering device 9 can steer the front wheel 3F of the vehicle 2 and steers the left front wheel 3FL and the right front wheel 3FR as steering wheels. The rear wheel steering device 10 can steer the rear wheel 3R of the vehicle 2, and steers the left rear wheel 3RL and the right rear wheel 3RR as steering wheels.

Typically, the front wheel steering device 9 includes a steering wheel (handle) 9a as a steering member that is a steering operator by the driver, and a steering that drives the steering wheel 9a to steer the front wheels 3F. And an angle imparting mechanism 9b. As the turning angle imparting mechanism 9b, for example, a so-called rack and pinion mechanism including a rack gear and a pinion gear can be used, but the present invention is not limited thereto. Further, the front wheel steering device 9 includes a VGRS (Variable Gear Ratio Steering) device 9c provided between the steering wheel 9a and the turning angle imparting mechanism 9b, a front wheel steering drive device (boost device) 9d, and the like. Composed. The VGRS device 9c is a gear ratio variable steering mechanism that can change the gear ratio of the steering wheel 9a. The front wheel steering device 9 has a steering characteristic changing function realized by the VGRS device 9c. The front wheel steering device 9 is, for example, a front wheel with respect to a steering wheel steering angle (cutting angle) that is an operation amount of the steering wheel 9a according to the driving state of the vehicle 2 (for example, the vehicle speed that is the traveling speed of the vehicle 2) by the VGRS device 9c. The steering angle of 3F (hereinafter sometimes referred to as “front wheel steering angle”) can be changed. The steering driver 9d is a so-called electric power steering device (EPS) that assists the steering force applied by the driver to the steering wheel 9a with power (steering assisting force) of an electric motor or the like. In the front wheel steering device 9, a steering force assisting function is realized by the steering driver 9d. The front wheel steering device 9 drives the driver's steering wheel by, for example, driving an electric motor or the like so that a steering assist force corresponding to the steering force applied to the steering wheel 9a from the driver can be obtained by the steering driver 9d. The steering operation (steering operation) for 9a can be assisted. The front wheel steering device 9 is electrically connected to the ECU 7, and the ECU 7 controls the VGRS device 9c, the steering driver 9d, and the like.

The rear wheel steering device 10 is a so-called ARS (Active Rear Steering) device. The rear wheel steering device 10 includes a rear wheel steering driver 10a that is driven by power from an electric motor or the like to steer the rear wheel 3R. In the rear wheel steering device 10, a steering characteristic changing function is realized by the steering driver 10a. Similar to the front wheel steering device 9, the rear wheel steering device 10, for example, uses a steering driver 10 a to control the steering angle of the rear wheel 3 </ b> R with respect to the steering wheel steering angle (hereinafter, “ It may be referred to as “rear wheel steering angle”). The rear wheel steering device 10 is electrically connected to the ECU 7, and the steering driver 10a and the like are controlled by the ECU 7. The rear wheel steering device 10 uses the ECU 7 to steer the rear wheel 3R with the same phase as or opposite to the steering angle of the front wheel 3F according to the driving state of the vehicle 2 (for example, vehicle speed or turning state).

In the vehicle control system 1, as described above, the front wheel steering device 9 and the rear wheel steering device 10 constitute the steering device 6 that is a four-wheel steering mechanism, and together with the left front wheel 3FL and the right front wheel 3FR, the left rear wheel 3RL and the right rear wheel. The wheel 3RR is also a steering wheel. Further, the front wheel steering device 9 and the rear wheel steering device 10 can change the steering angle of the front wheels 3F and the rear wheels 3R regardless of the steering operation by the driver under the control of the ECU 7.

The ECU 7 controls driving of each part of the vehicle 2 and includes an electronic circuit mainly composed of a known microcomputer including a CPU, a ROM, a RAM, and an interface. For example, various sensors and detectors are electrically connected to the ECU 7 and an electric signal corresponding to the detection result is input. Then, the ECU 7 executes the stored control program based on various input signals and various maps input from various sensors, detectors, etc., so that the drive device 4, the front wheel steering device 9, and the rear wheel steering are executed. A drive signal is output to each part of the vehicle 2 such as the device 10 to control the drive.

The vehicle control system 1 of the present embodiment includes, for example, a wheel speed sensor 11, a yaw rate / lateral acceleration sensor 12, and a forward detection device 13 as a detection device as various sensors and detectors. Four wheel speed sensors 11 are provided, one for each of the left front wheel 3FL, the right front wheel 3FR, the left rear wheel 3RL, and the right rear wheel 3RR. Each wheel speed sensor 11 detects wheel speeds VwFL, VwFR, VwRL, and VwRR, which are rotational speeds of the left front wheel 3FL, the right front wheel 3FR, the left rear wheel 3RL, and the right rear wheel 3RR, respectively. The yaw rate / lateral acceleration sensor 12 detects the yaw rate γ of the vehicle 2 and the lateral acceleration Gy that is acceleration in the lateral direction (direction intersecting (orthogonal) with the forward direction Y) generated in the vehicle body of the vehicle 2. The front detection device 13 detects the situation in the forward direction of the vehicle 2 (the direction along the forward direction Y). The front detection device 13 detects a situation within a predetermined detection range set in advance on the front side in the traveling direction of the vehicle 2. Here, the front detection device 13 is provided in a pair of left and right on the front side of the vehicle body of the vehicle 2.

The front detection device 13 includes, for example, the presence or absence of a peripheral object on the front side in the traveling direction of the vehicle 2, the relative physical quantity indicating the relative positional relationship between the detected peripheral object and the vehicle 2, You may make it detect at least 1 of the shape of the road where 2 drive | works, a lane, etc. The peripheral object on the front side in the traveling direction of the vehicle 2 is, for example, an object such as an obstacle on the front side in the traveling direction of the vehicle 2, a forward vehicle that travels on the front side in the traveling direction of the vehicle 2, or the like. Further, the front detection device 13 uses, for example, a relative speed (m / s), a relative distance (m), a relative deceleration (m / s) between the vehicle 2 and a surrounding object as the relative physical quantity detected by the front detection device 13. ² ), at least one of TTC (Time-To-Collision) (s) may be detected. Here, TTC (hereinafter sometimes referred to as “relative time”) corresponds to the time until the vehicle 2 reaches the surrounding object, and the relative distance between the vehicle 2 and the surrounding object is converted according to the relative speed. It corresponds to the time. The forward detection device 13 is, for example, a millimeter wave radar, a radar using a laser or an infrared ray, a short-range radar such as a UWB (Ultra Wide Band) radar, a sonar using a sound wave or an ultrasonic wave in an audible range, a CCD camera, etc. An image recognition device or the like that detects the situation on the front side in the traveling direction of the vehicle 2 by analyzing image data obtained by imaging the front in the traveling direction of the vehicle 2 with the imaging device of FIG.

Further, as described above, the ECU 7 is electrically connected to the VGRS device 9c, the steering driver 9d, and the steering driver 10a. The ECU 7 receives an electrical signal corresponding to the steering wheel steering angle (cutting angle) δd detected by the steering wheel steering angle sensor from the VGRS device 9c. The steering wheel steering angle δd is the steering angle of the steering wheel 9a (the rotation angle of the steering wheel 9a). The ECU 7 also receives an electrical signal corresponding to the front wheel steering angle δf detected by the front wheel steering angle sensor from the steering driver 9d. The front wheel steering angle δf is the steering angle of the front wheel 3F (the rotation angle of the front wheel 3F). Similarly, the ECU 7 receives an electric signal corresponding to the rear wheel steering angle δr detected by the rear wheel steering angle sensor from the steering driver 10a. As the rear wheel steering angle δr, an electric signal corresponding to the rear wheel steering angle δr, which is the steering angle of the rear wheel 3R (the rotation angle of the rear wheel 3R), is input.

Further, the vehicle control system 1 may include a communication system 14 that performs communication with the outside of the vehicle 2. The communication system 14 may include at least one of, for example, a vehicle-to-vehicle communication system, an infrastructure cooperation system, a GPS (Global Positioning System) system, and the like. The inter-vehicle communication system is a system that acquires various other vehicle information by communicating with an inter-vehicle communication device mounted on another vehicle. The infrastructure cooperation system is a system that acquires various infrastructure information by communicating with an infrastructure such as a road-to-vehicle communication device provided on the roadside. The GPS system is a system that receives a GPS signal representing position information (GPS information) of the vehicle 2 distributed by a GPS satellite. The ECU 7 is electrically connected to the communication system 14 and receives electrical signals corresponding to various information from the communication system 14. For example, the ECU 7 measures and calculates the position information of the vehicle 2, for example, GPS information (X coordinate; X, Y coordinate; Y), based on the GPS signal received by the communication system 14, and is stored in the database. The travel point of the vehicle 2 can be recognized by referring to map information such as road information. The vehicle control system 1 may further include a navigation device or the like.

The ECU 7 of this embodiment can control the front wheel steering device 9 and the rear wheel steering device 10 of the steering device 6 according to the vehicle body slip angle characteristic of the vehicle 2. Here, the vehicle body slip angle characteristic is a characteristic of the vehicle body slip angle with respect to the steering wheel steering angle when the ECU 7 controls the steering device 6 (the front wheel steering device 9 and the rear wheel steering device 10). The vehicle body slip angle is an angle formed by the longitudinal center line of the vehicle body of the vehicle 2 and the traveling direction (speed vector) of the vehicle 2, and is, for example, the longitudinal center of the vehicle body of the vehicle 2 with respect to the turning tangential direction of the vehicle 2. The angle formed by the line. The vehicle body slip angle represents, for example, that the vehicle body of the vehicle 2 is facing the inside of the turn as the angle becomes relatively large. The vehicle body slip angle is determined according to, for example, the front wheel steering angle, the rear wheel steering angle, or the like of the vehicle 2. The ECU 7 controls the front wheel steering device 9 and the rear wheel steering device 10 in accordance with the vehicle body slip angle characteristics of the vehicle 2 set in advance to steer the front wheels 3F and the rear wheels 3R, thereby setting the front wheel steering angle and the rear wheel steering angle. change. Here, the vehicle body slip angle characteristic of the vehicle 2 is set based on a slip angle gain Kβ described later. That is, as will be described later, the ECU 7 calculates the steering control amount by using the slip angle gain Kβ and controls the front wheel steering device 9 and the rear wheel steering device 10 to control the front wheel steering according to a predetermined vehicle body slip angle characteristic. The device 9 and the rear wheel steering device 10 can be controlled.

Furthermore, the ECU 7 of the present embodiment can control the vehicle 2 based on the detection result by the front detection device 13 and execute automatic driving control. The automatic driving control of the present embodiment is driving support control of the vehicle 2 using the detection result by the front detection device 13. Here, the automatic driving control is, for example, trajectory control that generates a target trajectory based on a detection result by the front detection device 13 and controls the front wheel steering device 9 and the rear wheel steering device 10 based on the target trajectory. The ECU 7 detects the situation on the front side in the traveling direction of the vehicle 2 detected by the front detection device 13, for example, the presence or absence of a peripheral object on the front side in the traveling direction of the vehicle 2, the relative physical quantity between the peripheral object and the vehicle 2, and the vehicle 2 traveling. Based on the shape of the road, the lane, and the like, a target trajectory that is a target travel trajectory of the vehicle 2 is generated. In this case, for example, the ECU 7 travels while avoiding obstacles ahead of the traveling direction of the vehicle 2 (lane keeping assist) in which the vehicle 2 that is the host vehicle travels while being maintained in the current lane (lane). A target locus of the vehicle 2 is generated according to the locus, a traveling locus that causes the vehicle 2 to follow the preceding vehicle, and the like. The ECU 7 may further generate the target locus in consideration of other vehicle information acquired by the communication system 14, infrastructure information, GPS information, and the like. Then, the ECU 7 controls the front wheel steering device 9 and the rear wheel steering device 10 according to the vehicle body slip angle characteristic so that the vehicle 2 travels in the traveling direction and posture according to the generated target locus. Note that the vehicle control system 1 can arbitrarily switch automatic driving control on and off in accordance with, for example, a driver switching operation via the changeover switch 15.

Next, an example of a schematic configuration of the ECU 7 will be described with reference to the block diagram of FIG. An example of basic control of the ECU 7 will be described with reference to this drawing.

The ECU 7 of the present embodiment includes a vehicle speed determination unit 7a, a target locus generation unit 7b, a steering control unit 7c, a gain setting unit 7d, and the like in terms of functional concept.

The vehicle speed determination unit 7a calculates a vehicle speed Vx that is the traveling speed of the vehicle 2 based on the wheel speed Vwi (i = FL, FR, RL, RR) of each wheel 3 input from each wheel speed sensor 11. The vehicle speed determination unit 7a outputs the calculated vehicle speed Vx to the steering control unit 7c.

The target trajectory generation unit 7b generates a target trajectory that is a target travel trajectory of the vehicle 2 based on the situation on the front side in the traveling direction of the vehicle 2 input from the front detection device 13. The target locus generation unit 7b is, for example, the presence or absence of a peripheral object on the front side in the traveling direction of the vehicle 2 detected by the front detection device 13, the relative physical quantity between the peripheral object and the vehicle 2, the shape of the road on which the vehicle 2 travels, the lane, etc. Based on the above, a target locus is generated. The target locus generation unit 7b outputs an index related to the generated target locus to the steering control unit 7c and the gain setting unit 7d. The index related to the target trajectory generated by the target trajectory generating unit 7b may include, for example, at least one of a turning radius R according to the target trajectory, a distance Lx to the obstacle, a lateral target moving distance Lyt, and the like.

The steering control unit 7c controls the front wheel steering device 9 and the rear wheel steering device 10, steers the front wheels 3F and the rear wheels 3R, and changes the front wheel steering angle and the rear wheel steering angle. The steering control unit 7c includes, for example, a steering wheel steering angle δd input from a steering wheel steering angle sensor of the VGRS device 9c, a vehicle speed Vx input from the vehicle speed determination unit 7a, and an index related to a target track input from the target track generation unit 7b, Based on a yaw rate gain Kγ and a slip angle gain Kβ input from a gain setting unit 7d described later, a target yaw rate γ and a target vehicle body slip angle β are calculated using a transfer function or the like. In this case, the steering control unit 7c may calculate the target yaw rate γ and the target vehicle body slip angle β without using the index related to the target trajectory when the automatic driving control is off. The target yaw rate γ and the target vehicle body slip angle β calculated by the steering control unit 7c are the yaw rate γ and the vehicle body slip angle β that are targets when the front wheel steering device 9 and the rear wheel steering device 10 are steering controlled. 2 is set to a value that stabilizes the behavior. The steering control unit 7c may further correct the target yaw rate γ and the target vehicle body slip angle β based on the yaw rate γ and the lateral acceleration Gy of the vehicle 2 input from the yaw rate / lateral acceleration sensor 12.

Then, the steering control unit 7c calculates control amounts (steering control amounts) of the front wheel steering angle δf and the rear wheel steering angle δr so that the calculated target yaw rate γ and target vehicle body slip angle β can be realized. For example, the steering control unit 7c reverses the control amounts of the front wheel steering angle δf and the rear wheel steering angle δr from the target yaw rate γ and the target vehicle body slip angle β using the vehicle model of the vehicle 2 stored in advance in the storage unit. Calculate. Then, the steering control unit 7c outputs a control command to the front wheel steering device 9 and the rear wheel steering device 10 based on the calculated control amounts of the front wheel steering angle and the rear wheel steering angle. That is, the steering control unit 7c feedback-controls the actual front wheel steering angle δf and the rear wheel steering angle δr detected by the front wheel steering angle sensor of the steering driver 9d and the rear wheel steering angle sensor of the steering driver 10a, The front wheel steering device 9 and the rear wheel steering device 10 are controlled so that the yaw rate γ and the vehicle body slip angle β converge on the target yaw rate γ and the target vehicle body slip angle β.

As a result, the vehicle 2 can travel along the target locus while the front wheels 3F and the rear wheels 3R are steered according to the vehicle body slip angle characteristics by the front wheel steering device 9 and the rear wheel steering device 10.

By the way, as described above, in the vehicle 2 including the steering device 6 including the front wheel steering device 9 and the rear wheel steering device 10 and the like, for example, it is attempted to realize vehicle characteristics along with vehicle stabilization and driver feeling. Assume a case. In this case, the vehicle body slip angle characteristic of the vehicle 2 may be set such that, for example, the vehicle body slip angle is in the vicinity of 0 [rad] in a turning state in a high speed range where the vehicle speed is equal to or higher than a predetermined vehicle speed set in advance. preferable. Here, when the vehicle body slip angle characteristic is set as described above, the four-wheel steering vehicle 2 can improve the vehicle stability and the driver feeling, while the two-wheel steering (2 Wheel Steering). 3, the longitudinal center line L1 of the vehicle body 2A tends to face the turning outer side relative to the turning center, as illustrated in FIG. Accordingly, as illustrated in FIG. 3, the detection range X <b> 1 by the front detection device 13 (see FIG. 1) provided in the vehicle body 2 </ b> A also turns relative to the turning center on the front side in the traveling direction of the vehicle 2. It will turn to the outside. For this reason, when the vehicle 2 executes the automatic driving control (trajectory control) described above with such vehicle characteristics, depending on the viewing angle of the front detection device 13 or the like, the detection of the front detection device 13 during turning is detected. There is a possibility that the range does not become an appropriate range, and the situation on the front side in the traveling direction necessary for the automatic operation control cannot be properly detected.

Therefore, the ECU 7 of the present embodiment changes the vehicle body slip angle characteristic of the vehicle 2 according to whether or not the automatic driving control is executed. That is, the ECU 7 changes the vehicle body slip angle characteristic between when the automatic driving control is executed and when the automatic driving control is not executed. Thereby, the ECU 7 can appropriately perform the automatic driving control in the vehicle 2 in which the front wheels 3F and the rear wheels 3R are the steering wheels. In the following description, the case where the automatic driving control is executed may be referred to as “at the time of automatic driving control”, and the case where the automatic driving control is not executed may be referred to as “at the time of driver steering”.

Here, the vehicle body slip angle characteristic of the vehicle 2 is set based on the slip angle gain Kβ as described above. The slip angle gain Kβ is used when the target vehicle body slip angle β is calculated as described above, and corresponds to, for example, the ratio between the vehicle body slip angle β of the vehicle 2 and the steering wheel steering angle δd of the vehicle 2. The ECU 7 of the present embodiment changes the vehicle body slip angle characteristic of the vehicle 2 by changing the slip angle gain Kβ.

Typically, the ECU 7 changes the vehicle body slip angle characteristic so as to have a tendency as illustrated in FIG. 3 when comparing the driver steering and the automatic driving control. That is, the ECU 7 relatively faces the vehicle 2 turning outward during steering of the driver (refer to the vehicle body 2A, the front-rear direction center line L1, and the detection range X1 in FIG. 3), and the vehicle body of the vehicle 2 during automatic driving control. The vehicle body slip angle characteristic is changed so that the vehicle is relatively directed toward the inside of the turn (see the vehicle body 2B, the front-rear direction center line L2, and the detection range X2 in FIG. 3).

Here, the ECU 7 changes the vehicle body slip angle characteristic of the vehicle 2 by changing the vehicle slip angle gain Kβ by switching the vehicle body slip angle gain map (or mathematical model) between the driver steering and the automatic driving control. The vehicle body slip angle gain map is a map for calculating the slip angle gain Kβ.

The ECU 7 of the present embodiment switches the vehicle body slip angle gain map to be used depending on whether the gain setting unit 7d (see FIG. 2) is at the time of driver steering or automatic driving control. The gain setting unit 7d uses the vehicle body slip angle gain maps corresponding to the steering operation and the automatic driving control, respectively, and the vehicle speed Vx input from the vehicle speed determination unit 7a and the target input from the target locus generation unit 7b. A slip angle gain Kβ is calculated based on an index related to the trajectory. Then, the gain setting unit 7d outputs the slip angle gain Kβ calculated according to the situation to the steering control unit 7c.

The gain setting unit 7d calculates a slip angle gain Kβ used during driver steering according to the vehicle speed Vx input from the vehicle speed determining unit 7a using the first vehicle body slip angle gain map during driver steering. The first vehicle body slip angle gain map typically has a vehicle body slip angle in the vicinity of 0 [rad] in a turning state in a high speed region, and can achieve vehicle stabilization and improved driver feeling. The slip angle characteristic is set.

FIG. 4 is a diagram showing an example of a first vehicle body slip angle gain map m1 used during driver steering. In the first vehicle body slip angle gain map m1, the horizontal axis represents the vehicle speed, and the vertical axis represents the slip angle gain Kβ used during driver steering. The first vehicle body slip angle gain map m1 describes the relationship between the vehicle speed and the slip angle gain Kβ. The first vehicle body slip angle gain map m1 is stored in the storage unit of the ECU 7 after the relationship between the vehicle speed and the slip angle gain Kβ is set in advance based on actual vehicle evaluation and the like. In the first vehicle body slip angle gain map m1, the slip angle gain Kβ decreases as the vehicle speed increases, and is set to 0 in a high-speed range that is equal to or higher than a predetermined vehicle speed. Based on the first vehicle body slip angle gain map m1, the gain setting unit 7d calculates a slip angle gain Kβ used during driver steering from the input vehicle speed.

In this case, the vehicle 2 has a higher vehicle speed, and as the slip angle gain Kβ calculated by the gain setting unit 7d approaches 0, the vehicle body slip angle becomes near 0 [rad] and the vehicle body tends to turn in the tangential direction of the turn. As a result, the vehicle control system 1 can achieve vehicle stabilization and improvement of driver feeling in a turning state in a high speed region during driver steering.

In the present embodiment, the gain setting unit 7d has been described as calculating and setting the slip angle gain Kβ using the first vehicle body slip angle gain map m1, but the present embodiment is not limited to this. For example, the gain setting unit 7d may calculate and set the slip angle gain Kβ based on a mathematical model corresponding to the first vehicle body slip angle gain map m1.

On the other hand, at the time of automatic driving control, the gain setting unit 7d uses the second vehicle body slip angle gain map to convert the vehicle speed Vx input from the vehicle speed determination unit 7a and the index related to the target track input from the target track generation unit 7b. Accordingly, a slip angle gain Kβ used during automatic operation control is calculated. Here, the gain setting unit 7d calculates the slip angle gain Kβ based on the vehicle speed Vx and the turning radius R corresponding to the target locus. That is, the ECU 7 of the present embodiment changes the vehicle body slip angle characteristic of the vehicle 2 based on at least one of the vehicle speed Vx of the vehicle 2 or the turning radius R of the vehicle, here both. In other words, the ECU 7 changes the vehicle body slip angle characteristic of the vehicle 2 based on the target locus that is the target locus of the vehicle 2 in the automatic operation control. The second vehicle body slip angle gain map typically has the detection range of the front detection device 13 as far as possible in the trajectory direction of the target trajectory according to the vehicle speed Vx and the curving radius R even in a turning state in a high speed region. Such a vehicle body slip angle characteristic is set.

FIG. 5 is a diagram showing an example of a second vehicle body slip angle gain map m2 used during automatic operation control. In the second vehicle body slip angle gain map m2, the horizontal axis represents the vehicle speed, and the vertical axis represents the slip angle gain Kβ used during automatic operation control. The second vehicle body slip angle gain map m2 describes the relationship between the vehicle speed, the turning radius, and the slip angle gain Kβ. The second vehicle body slip angle gain map m2 is stored in the storage unit of the ECU 7 after the relationship between the vehicle speed, the turning radius, and the slip angle gain Kβ is set in advance based on actual vehicle evaluation and the like. Schematically, the second vehicle body slip angle gain map m2 is set such that the slip angle gain Kβ in the high speed region is different from the first vehicle body slip angle gain map m1. Based on the second vehicle body slip angle gain map m2, the gain setting unit 7d calculates a slip angle gain Kβ used during automatic operation control from the input vehicle speed and turning radius. That is, the ECU 7 typically changes the vehicle body slip angle characteristic in the high speed range according to whether or not the automatic driving control is executed.

More specifically, the second vehicle body slip angle gain map m2 is a future vehicle position predicted from the current vehicle speed, the turning radius according to the target locus, and the detection range of the front detection device 13 is the locus of the target locus. A slip angle gain Kβ (in other words, a vehicle body slip angle characteristic) is set so that the vehicle posture faces the direction. In the second vehicle body slip angle gain map m2, the slip angle gain Kβ decreases as the vehicle speed increases, becomes 0 at a predetermined vehicle speed set in advance, and gradually decreases below 0 in a higher speed range than the predetermined vehicle speed. Is set to Further, in the second vehicle body slip angle gain map m2, the slip angle gain Kβ is set to become smaller as the turning radius becomes smaller in a high speed range than the predetermined vehicle speed. That is, the second vehicle body slip angle gain map m2 is set so as to have a vehicle body slip angle characteristic that is head-in (the vehicle body is directed toward the inside of the vehicle) as compared with the case of driver steering in accordance with the turning radius. Based on the second vehicle body slip angle gain map m2, the gain setting unit 7d calculates a slip angle gain Kβ used during driver steering from the input vehicle speed and turning radius.

In this case, in the vehicle 2, as the vehicle speed increases and the slip angle gain Kβ calculated by the gain setting unit 7d decreases, and as the turning radius decreases and the calculated slip angle gain Kβ decreases, the vehicle body slip angle becomes relative. The vehicle body of the vehicle 2 tends to turn relatively inside. That is, the ECU 7 is directed so that the vehicle body slip angle of the vehicle 2 is relatively larger when the automatic driving control is being executed than when the automatic driving control is not being executed, that is, facing the inside of the turn. Thus, the vehicle body slip angle characteristic of the vehicle 2 is changed. More specifically, when executing the automatic operation control, the ECU 7 sets the vehicle body slip angle characteristic of the vehicle 2 so that the vehicle body slip angle of the vehicle 2 becomes relatively larger as the vehicle speed of the vehicle 2 becomes relatively higher. Will be changed. Similarly, when executing the automatic driving control, the ECU 7 changes the vehicle body slip angle characteristic of the vehicle 2 so that the vehicle body slip angle of the vehicle 2 becomes relatively larger as the turning radius of the vehicle 2 becomes relatively smaller. Will be.

As a result, the vehicle control system 1 can make the detection range of the front detection device 13 as far as possible in the trajectory direction of the target trajectory even when the vehicle 2 is turning in the high speed region during the automatic driving control. .

The ECU 7 changes the steering angle change rate (amount of change per unit time) of the front wheels 3F and the rear wheels 3R when the automatic driving control is switched from on to off and when the automatic driving control is switched from off to on. And so-called change rate guard of the front wheel steering angle and the rear wheel steering angle may be performed. Here, the time when the automatic driving control is switched from ON to OFF is a time when switching from the state in which the automatic driving control is executed to the state in which the automatic driving control is not executed. In addition, when automatic driving control is turned on from off is when switching from a state in which automatic driving control is not executed to a state in which automatic driving control is executed. That is, the ECU 7 limits the steering control amount (control command) when starting the automatic driving control and ending the automatic driving control, and limits the change rate of the front wheel steering angle and the rear wheel steering angle. As a case where the automatic driving control is switched from on to off, for example, when the driver performs a large steering operation, the forward detection device 13 loses the preceding vehicle and cannot generate the target locus. For example, when the driver switches from on to off. Examples of the case where the automatic driving control is turned on from off include a case where the driver switches from off to on via the changeover switch 15.

Next, an example of control by the ECU 7 will be described with reference to the flowchart of FIG. Note that these control routines are repeatedly executed at a control cycle of several ms to several tens of ms.

First, the ECU 7 determines whether or not the driving support system is operating, that is, whether or not automatic driving control is being executed (step ST1).

If the ECU 7 determines that the driving support system is operating, that is, that automatic driving control is being executed (step ST1: Yes), the ECU 7 uses the second vehicle body slip angle gain map m2 illustrated in FIG. Then, the slip angle gain Kβ is calculated (step ST2). Then, the ECU 7 calculates the target vehicle body slip angle β using the calculated slip angle gain Kβ, and calculates the control amounts of the front wheel steering angle and the rear wheel steering angle.

Next, the ECU 7 determines whether or not automatic driving control (driving support) is being switched on / off (step ST3). For example, when the automatic driving control is being switched on / off, the second vehicle body slip angle gain map m2 is used from the front wheel steering angle and the rear wheel steering angle when the first vehicle body slip angle gain map m1 is used. This is the case when the vehicle is in the process of shifting to the front wheel steering angle or the rear wheel steering angle, or vice versa.

Next, when it is determined that the automatic driving control is being switched on / off (step ST3: Yes), the ECU 7 limits the change rate of the front wheel steering angle and the rear wheel steering angle, and performs the change rate guard ( Step ST4).

Then, the ECU 7 performs steering control by controlling the front wheel steering device 9 and the rear wheel steering device 10 based on the calculated control amounts of the front wheel steering angle and the rear wheel steering angle (step ST5), and ends the current control cycle. Then, the next control cycle is started.

ECU7 will transfer to the process of step ST5, without performing change rate guard, when it determines with not switching ON / OFF of automatic driving | operation control in step ST3 (step ST3: No).

When it is determined in step ST1 that the driving support system is not operating, that is, the automatic driving control is not being executed (step ST1: No), the ECU 7 displays the first vehicle body slip angle gain map m1 illustrated in FIG. In use, the slip angle gain Kβ is calculated (step ST6). Then, the ECU 7 calculates the target vehicle body slip angle β using the calculated slip angle gain Kβ, calculates the control amounts of the front wheel steering angle and the rear wheel steering angle, and proceeds to the processing of step ST3.

The vehicle control system 1 configured as described above can make the vehicle body slip angle characteristic different between automatic driving control for executing automatic driving control and driver steering without executing automatic driving control. . Therefore, in the vehicle 2 in which the front wheels 3F and the rear wheels 3R are the steering wheels, the vehicle control system 1 can detect the vehicle body with respect to steering even when the ideal vehicle posture is different between automatic driving control and driver steering. The slip angle posture can be arbitrarily controlled appropriately according to the presence or absence of automatic operation control. Thereby, the vehicle control system 1 can appropriately perform the automatic driving control in the vehicle 2 in which the front wheels 3F and the rear wheels 3R are the steering wheels.

For example, the vehicle control system 1 can set the vehicle body slip angle of the vehicle 2 in the vicinity of 0 [rad] and turn the vehicle body in the turning tangential direction when the driver is steering, for example. As a result, the vehicle control system 1 can stabilize the vehicle and improve the driver feeling in a turning state in a high speed region at the time of driver steering.

On the other hand, the vehicle control system 1 changes the vehicle body slip angle characteristic to a vehicle body slip angle characteristic different from that during driver steering, for example, during automatic driving control, and changes the vehicle body slip angle characteristic of the vehicle 2 based on the vehicle speed, turning radius, etc. change. In other words, the vehicle control system 1 changes the vehicle body slip angle characteristic of the vehicle 2 based on the target locus that is the target locus of the vehicle 2 in the automatic driving control. Thereby, at the time of automatic driving control, for example, the vehicle control system 1 may relatively increase the vehicle body slip angle of the vehicle 2 in a turning state in a high speed range so that the vehicle body relatively faces the inside of the turn. it can. As a result, at the time of automatic driving control, the vehicle control system 1 can make the detection range by the front detection device 13 face the trajectory direction of the target trajectory even when the vehicle 2 is turning in the high speed range. As a result, the vehicle control system 1 can set the detection range of the front detection device 13 during turning during the automatic driving control to an appropriate range, and appropriately detect the situation on the front side in the traveling direction necessary for the automatic driving control. can do.

Therefore, the vehicle control system 1 varies the vehicle body slip angle characteristics in the high-speed range between automatic driving control and driver steering, thereby improving vehicle stabilization and driver feeling during driver steering. In addition, it is possible to properly detect the situation ahead in the traveling direction necessary for the automatic operation control by the front detection device 13 during the automatic operation control, and it is possible to appropriately continue the automatic operation control. As a result, the vehicle control system 1 can achieve both vehicle stabilization and improvement in driver feeling and continuation of automatic driving control.

Further, the vehicle control system 1 limits the steering control amounts of the front wheel steering device 9 and the rear wheel steering device 10 when switching on / off of the automatic driving control, and the rate of change of the front wheel steering angle and the rear wheel steering angle. Limit. As a result, the vehicle control system 1 can prevent the front wheel steering angle and the rear wheel steering angle from changing discontinuously at the time of switching between driver operation and automatic driving control, and a shock occurs. Can be prevented.

According to the vehicle control system 1 according to the embodiment described above, the steering device 6 that can steer the front wheels 3F and the rear wheels 3R of the vehicle 2, and the front detection device that detects the situation on the front side in the traveling direction of the vehicle 2. 13, the steering device 6 can be controlled according to the vehicle body slip angle characteristic of the vehicle 2, the vehicle 2 can be controlled based on the detection result by the front detection device 13, and automatic driving control can be executed. ECU 7 which changes the vehicle body slip angle characteristic of vehicle 2 according to the presence or absence of execution of control. Therefore, the vehicle control system 1 and the ECU 7 can appropriately perform automatic driving control in the vehicle 2 in which the front wheels 3F and the rear wheels 3R are steering wheels.

[Embodiment 2]
FIG. 7 is a flowchart illustrating an example of control by the ECU of the vehicle control system according to the second embodiment. The vehicle control system and the control device according to the second embodiment are different from the first embodiment in that the vehicle body slip angle characteristic of the vehicle is changed according to the contact prediction with the surrounding object. In addition, about the structure, operation | movement, and effect which are common in embodiment mentioned above, the overlapping description is abbreviate | omitted as much as possible. Moreover, about each structure of the vehicle control system which concerns on Embodiment 2, and a control apparatus, FIG.1, FIG.2 etc. are referred suitably.

In the vehicle control system 201 (see FIG. 1) of the present embodiment, the ECU 7 changes the vehicle body slip angle characteristic according to the contact prediction between the vehicle 2 and an object around the vehicle 2. For example, the ECU 7 predicts contact between the vehicle 2 and an object around the vehicle 2 based on the detection result by the front detection device 13, and according to this, the emergency avoidance pre-crash safety (Pre-Crash Safety, “hereinafter, (It may be called “emergency avoidance PCS”.) Control is executed.

ECU7 performs contact prediction with the vehicle 2 and a surrounding object based on the said relative physical quantity which the front detection apparatus 13 detected, for example. For example, when the relative distance between the vehicle 2 and a surrounding object is equal to or less than a preset relative distance threshold, or when the TTC (relative time) is equal to or less than a preset TTC threshold, the ECU 7 Presence. " The relative distance threshold value and the TTC threshold value are set in advance based on actual vehicle evaluation and the like, and are stored in the storage unit of the ECU 7. When the ECU 7 predicts “possibility of contact”, the emergency avoidance PCS control performs various processes to prepare for contact between the vehicle 2 and surrounding objects. In this case, for example, the ECU 7 automatically performs emergency braking by controlling the braking device 5. Further, in this case, for example, the ECU 7 drives the warning device to warn the driver that there is a possibility of contact with surrounding objects, and prompts the driver to perform emergency braking. Also good.

Then, the ECU 7 of the present embodiment changes the vehicle body slip angle characteristic according to the prediction of the possibility of contact between the vehicle 2 and surrounding objects as described above. More specifically, the ECU 7 determines that the vehicle body slip angle of the vehicle 2 is automatically driven even when the contact between the vehicle 2 and an object in the vicinity of the vehicle 2 is predicted or when the automatic drive control is being executed. The vehicle body slip angle characteristic of the vehicle 2 is changed so as to be equivalent to the case where the control is not executed. That is, even when the automatic operation control is being executed, the ECU 7 switches the vehicle body slip angle characteristic to a characteristic that emphasizes behavioral stability under a situation where the emergency avoidance PCS is activated. Here, the gain setting unit 7d calculates the slip angle gain Kβ using the first vehicle body slip angle gain map m1 illustrated in FIG. 4 when the contact between the vehicle 2 and an object around the vehicle 2 is predicted. To do.

Next, an example of control by the ECU 7 will be described with reference to the flowchart of FIG.

When it is determined in step ST1 that the driving support system is operating, that is, the automatic driving control is being executed (step ST1: Yes), the ECU 7 determines whether or not the emergency avoidance PCS is operated (step ST1). Step ST201). For example, the ECU 7 performs contact prediction between the vehicle 2 and surrounding objects based on the detection result of the front detection device 13 and determines whether or not to operate the emergency avoidance PCS.

When the ECU 7 operates the emergency avoidance PCS, that is, when it is predicted that “there is a possibility of contact” (step ST201: Yes), the ECU 7 uses the first vehicle body slip angle gain map m1 illustrated in FIG. Gain Kβ is calculated (step ST202). Then, the ECU 7 calculates the target vehicle body slip angle β using the calculated slip angle gain Kβ, calculates the control amounts of the front wheel steering angle and the rear wheel steering angle, and proceeds to the processing of step ST3.

When it is predicted that the emergency avoidance PCS does not operate, that is, “no contact possibility” (step ST201: No), the ECU 7 uses the second vehicle body slip angle gain map m2 illustrated in FIG. Gain Kβ is calculated (step ST203). Then, the ECU 7 calculates the target vehicle body slip angle β using the calculated slip angle gain Kβ, calculates the control amounts of the front wheel steering angle and the rear wheel steering angle, and proceeds to the processing of step ST3.

The vehicle control system 201 and the ECU 7 according to the embodiment described above can appropriately perform automatic driving control in the vehicle 2 in which the front wheels 3F and the rear wheels 3R are steering wheels.

In the vehicle control system 201 according to the embodiment described above, the ECU 7 changes the vehicle body slip angle characteristic of the vehicle 2 according to the contact prediction between the vehicle 2 and an object around the vehicle 2. As a result, the vehicle control system 201 and the ECU 7 switch the vehicle body slip angle characteristic to a characteristic that emphasizes behavioral stability under a situation where the emergency avoidance PCS is activated even when the automatic driving control is being executed. Can do. Accordingly, the vehicle control system 201 and the ECU 7 change the vehicle behavior to the stable side when the contact between the vehicle 2 and an object around the vehicle 2 is predicted even when the automatic driving control is being executed. Thus, it is possible to safely deal with contact.

In addition, the vehicle control system and the control device according to the above-described embodiment of the present invention are not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims. The vehicle control system and the control device according to the present embodiment may be configured by appropriately combining the components of the embodiments described above.

In the above description, the control device has been described as being shared by the ECU 7, but is not limited thereto. For example, the control device may be configured separately from the ECU 7, and may be configured to mutually exchange information such as a detection signal, a drive signal, and a control command.

The steering device 6 described above may be of a so-called steer-by-wire system in which there is no mechanical connection between the steering wheel 9a and the front wheels 3F and the rear wheels 3R.

In the above description, the automatic driving control has been described as so-called trajectory control. However, the present invention is not limited to this, and the driving device 4, the braking device 5, the steering device 6 and the like are simply based on the detection result by the front detection device 13. For example, follow-up control that automatically tracks the preceding vehicle may be possible.

In the above description, the control device has been described as changing the vehicle body slip angle characteristic of the vehicle 2 by changing the slip angle gain, but the present invention is not limited to this.

DESCRIPTION OF SYMBOLS 1,201 Vehicle control system 2 Vehicle 2A, 2B Car body 3 Wheel 3F Front wheel 3R Rear wheel 4 Drive device 5 Braking device 6 Steering device 7 ECU (control device)
7a Vehicle speed determination unit 7b Target locus generation unit 7c Steering control unit 7d Gain setting unit

8a Accelerator pedal

8b Brake pedal 9 Front wheel steering device 10 Rear wheel steering device 11 Wheel speed sensor 12 Yaw rate / lateral acceleration sensor 13 Forward detection device (detection device)
14 Communication system 15 Changeover switch

Claims

A steering device capable of steering the front and rear wheels of the vehicle;
A detection device for detecting a situation on the front side in the traveling direction of the vehicle;
The steering device can be controlled according to the vehicle body slip angle characteristic of the vehicle, and the vehicle can be controlled based on the detection result of the detection device to execute automatic driving control. A control device that changes a vehicle body slip angle characteristic according to presence or absence of the vehicle,
Vehicle control system.
The control device changes a vehicle body slip angle characteristic of the vehicle in a high speed range in which a vehicle speed of the vehicle is equal to or higher than a predetermined vehicle speed set in advance according to whether or not the automatic driving control is performed.
The vehicle control system according to claim 1.
The control device changes the vehicle body slip angle characteristic of the vehicle based on at least one of the vehicle speed or the turning radius of the vehicle.
The vehicle control system according to claim 1 or 2.
The control device changes a vehicle body slip angle characteristic of the vehicle based on a target trajectory that is a target travel trajectory of the vehicle generated based on a detection result by the detection device.
The vehicle control system according to any one of claims 1 to 3.
When the automatic driving control is being executed, the control device causes the vehicle body slip angle of the vehicle to be relatively large compared to a case where the automatic driving control is not being executed. Change angular characteristics,
The vehicle control system according to any one of claims 1 to 4.
The control device changes the vehicle body slip angle characteristic of the vehicle so that the vehicle body slip angle of the vehicle becomes relatively larger as the vehicle speed of the vehicle becomes relatively higher when the automatic driving control is executed. ,
The vehicle control system according to any one of claims 1 to 5.
When performing the automatic driving control, the control device changes the vehicle body slip angle characteristic of the vehicle so that the vehicle body slip angle of the vehicle becomes relatively larger as the turning radius of the vehicle becomes relatively smaller. To
The vehicle control system according to any one of claims 1 to 6.
The control device switches from a state in which the automatic driving control is performed to a state in which the automatic driving control is not performed, and enters a state in which the automatic driving control is performed from a state in which the automatic driving control is not performed. When switching, the rate of change of the steering angle of the front wheels and the rear wheels is limited,
The vehicle control system according to any one of claims 1 to 7.
The control device changes a vehicle body slip angle characteristic of the vehicle according to a contact prediction between the vehicle and an object around the vehicle.
The vehicle control system according to any one of claims 1 to 8.
In the case where the contact between the vehicle and an object in the vicinity of the vehicle is predicted, the control device determines whether the vehicle slip angle of the vehicle performs the automatic driving control even when the automatic driving control is executed. Changing the vehicle body slip angle characteristic to be equivalent to the case where it is not executed,
The vehicle control system according to any one of claims 1 to 9.
The vehicle body slip angle characteristic of the vehicle is set based on a slip angle gain corresponding to a ratio of the vehicle body slip angle of the vehicle and the steering wheel steering angle of the vehicle,
The control device changes a vehicle body slip angle characteristic of the vehicle by changing the slip angle gain;
The vehicle control system according to any one of claims 1 to 10.
Based on the detection result by the detection device that detects the front side direction of the vehicle in which the front wheels and the rear wheels are the steering wheels, the vehicle can be controlled to execute the automatic driving control, and the automatic driving control can be executed. The vehicle body slip angle characteristic is changed according to the presence or absence of the vehicle,
Control device.