JP2019209889A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control system capable of maintaining traveling stability of a vehicle even when switching from automatic operation to manual operation while the vehicle is turning. SOLUTION: An automatic driving control unit 11, a manual driving control unit 13, a driving switching control unit 12 for switching between automatic driving control and manual driving control, and traveling for judging whether or not a vehicle satisfies a traveling stability condition The stability determination unit 14 and the driving switching control unit 12 do not satisfy the driving stability condition by the driving stability determination unit 14 when switching from the automatic driving control to the manual driving control while the vehicle is turning. When it is determined that the vehicle control system 1 performs the steering control of the vehicle as the manual driving control, the driving force distribution control of the vehicle switches to the partial manual driving control as the automatic driving control. .. [Selection diagram] Figure 1

Description

  The present invention relates to a vehicle control system.

  2. Description of the Related Art Conventionally, an automatic driving control device that determines a driving operation recommended for a driver when switching from automatic driving to manual driving has been proposed (for example, see Patent Document 1). According to this automatic operation control device, when switching from automatic operation to manual operation, the driver can easily perform an appropriate driving operation.

  However, depending on the driver's condition, switching from automatic operation to manual operation may not be appropriate in the first place. Therefore, an automatic driving support device that monitors the state of the driver by the driver monitoring unit and sets a level indicating whether or not switching from automatic driving to manual driving is possible based on the monitoring result is provided. It has been proposed (see, for example, Patent Document 2).

JP 2017-94963 A JP 2017-97518 A

  However, when the vehicle is turning, for example, when switching from automatic driving to manual driving, depending on the state of the vehicle, the driver may not be suitable as a situation for taking over driving. In this case, if switching to the manual operation is performed, there is a possibility that the running stability of the vehicle cannot be maintained.

  The present invention has been made in view of the above, and an object of the present invention is to provide a vehicle control system capable of maintaining the running stability of a vehicle even when switching from automatic driving to manual driving while the vehicle is turning. .

  (1) The present invention provides an automatic driving control unit (for example, an automatic driving control unit 11 to be described later) that automatically controls a vehicle, and a manual driving control unit (for example, a manual driving control unit that controls the vehicle according to a driver's operation). A vehicle control system (for example, a later-described manual operation control unit 13) and a driving switching control unit (for example, a later-described driving switching control unit 12) that switches between the automatic operation control and the manual operation control. The vehicle control system 1) includes a travel stability determination unit (for example, a travel stability determination unit 14 to be described later) that determines whether or not the vehicle satisfies a travel stability condition. When executing the switching from the automatic driving control to the manual driving control during turning of the vehicle, when the driving stability determining unit determines that the driving stability condition is not satisfied, Driving force distribution control of the vehicle steering control of the serial vehicle while a manual operation control performs the switching to some manual operation control for automatic operation control, to provide a vehicle control system.

  (2) When the driving stability control unit determines that the driving stability condition is satisfied after the switching to the partial manual driving control is performed, the driving switching control unit also performs the steering control. It is preferable to perform switching to full manual operation control, which is manual operation control.

  (3) The travel stability determination unit includes a straight travel determination unit (for example, a straight travel determination unit 141 described later) that determines straight travel performance of the vehicle, and a grip determination unit (for example, described later) that determines grip performance of the tire of the vehicle. The grip determination unit 142), and when the straight travel determination unit determines that the straight travel performance is good and the grip determination unit determines that the grip performance is good, the vehicle It is preferable to determine that the running stability is good.

  (4) The straight travel determination unit determines that the straight travel performance is good when the turning angle of the tire of the vehicle is equal to or smaller than a predetermined threshold and the lateral acceleration of the vehicle is equal to or smaller than the predetermined threshold. Is preferred.

  (5) It is preferable that the grip determination unit determines that the grip performance is good when the tire slip ratio of each wheel of the vehicle is equal to or less than a predetermined threshold value.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle control system which can maintain the driving | running | working stability of a vehicle can be provided even at the time of switching from the automatic driving | running | working to the manual driving | running | working while the vehicle is turning.

It is a figure showing composition of a vehicle control system concerning one embodiment of the present invention. It is a flowchart which shows the procedure of the process of driving | operation switching control during the turning driving | running | working of a vehicle.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a vehicle control system 1 according to an embodiment of the present invention. A vehicle on which the vehicle control system 1 according to the present embodiment is mounted is constituted by, for example, an electric vehicle capable of four-wheel drive. As will be described in detail later, the vehicle control system 1 according to the present embodiment has a configuration capable of automatically controlling the driving of the vehicle, and enables automatic driving equivalent to level 3 defined by the Ministry of Land, Infrastructure, Transport and Tourism. .

  As shown in FIG. 1, the vehicle control system 1 includes an ECU 10, an external sensing device 20, an HMI (Human Machine Interface) 30, a navigation device 40, a vehicle sensor 50, and an EPS (Electric Power Steering) 61. VSA (Vehicle Stability Assist) 62, AWD (All-Wheel-Drive) 63, ESB (Electric Servo Brake) 64, driving force output device 71, brake device 72, and steering device 73.

  The external sensing device 20 includes a camera 21, a radar (Radar) 22, and a lidar (Lidar) 23.

  At least one camera 21 is provided at an arbitrary location of the host vehicle, and images around the host vehicle are acquired to obtain image information. The camera 21 is a monocular camera or a stereo camera. For example, a digital camera using a solid-state image sensor such as a CCD or a CMOS is used.

  At least one radar 22 is provided at an arbitrary location of the host vehicle, and detects the position (distance and direction) of an object existing around the host vehicle. Specifically, the radar 22 irradiates an electromagnetic wave such as a millimeter wave around the vehicle, and detects a reflected wave in which the irradiated electromagnetic wave is reflected by the object, thereby detecting the position of the object.

  At least one rider 23 is provided at an arbitrary location of the host vehicle, and detects the position (distance and azimuth) and properties of an object existing around the host vehicle. Specifically, the lidar 23 irradiates an electromagnetic wave having a wavelength shorter than millimeter waves (electromagnetic wave such as ultraviolet light, visible light, and near infrared light) around the vehicle in a pulse shape, and the irradiated electromagnetic wave is caused by an object. By detecting the scattered scattered wave, the position and property of an object existing at a farther distance than the radar 22 are detected.

  The external sensing device 20 functions as an advanced driver assistance system ADAS (Advanced Driver Assistance Systems). Specifically, the external sensing device 20 comprehensively evaluates each piece of information acquired by the above-described camera 21, radar 22, lidar 23, and the like by sensor fusion technology, and more accurate information is described in detail later. It outputs to ECU10.

  The HMI 30 is an interface that presents various types of information to the driver and the like and receives input operations by the driver and the like. The HMI 30 includes, for example, a display device, a seat belt device, a handle touch sensor, a driver monitor camera, various operation switches, and the like (not shown).

  The display device is, for example, a touch panel display device that displays an image and receives an operation by a driver or the like. The seat belt device includes, for example, a seat belt pretensioner, and vibrates the seat belt when switching from automatic operation to manual operation is performed regardless of the driver's will due to, for example, a vehicle failure. Informs and warns the driver. The steering wheel touch sensor is provided on the steering wheel of the vehicle, and detects the contact of the driver with the steering wheel and the pressure with which the driver grips the steering wheel. The driver monitor camera images the driver's face and upper body. The various operation switches include, for example, a GUI-type or mechanical-type automatic operation changeover switch that instructs start and stop of automatic operation. The HMI 30 may include various communication devices that have a function of communicating with the outside.

  The navigation device 40 includes a GNSS (Global Navigation Satellite System) reception unit 41, a route determination unit 42, and a storage unit 43. Further, the navigation device 40 includes a display device, a speaker, an operation switch, and the like for the driver or the like to use the navigation device 40 in the above-described HMI 30.

  The GNSS receiver 41 identifies the position of the vehicle based on the received signal from the GNSS satellite. However, the position of the vehicle may be specified by acquired information from the vehicle sensor 50 described in detail later.

  The route determination unit 42 uses, for example, the map information stored in the storage unit 43 that details the route from the position of the host vehicle specified by the GNSS reception unit 41 to the destination input by the driver or the like in a later stage. Determine by reference. The route determined by the route determination unit 42 is route-guided to the driver or the like by the display device, the speaker, or the like in the HMI 30 described above.

  The storage unit 43 stores highly accurate map information MPU (Map Position Unit). Map information includes, for example, road type, road lane number, emergency parking zone position, lane width, road gradient, road position, lane curve curvature, lane merge and branch point positions, road signs, etc. Information, intersection position information, traffic signal presence / absence information, stop line position information, traffic jam information, other vehicle information, and the like.

  In addition, the navigation apparatus 40 may be comprised by terminal devices, such as a smart phone and a tablet terminal, for example. The navigation device 40 includes various cellular networks, a vehicle-mounted dedicated communication unit TCU (Telematics Communication Unit), and the like, all of which are not shown, and can be transmitted to and received from a cloud server or the like. As a result, vehicle position information and the like are transmitted to the outside, and the above-described map information is updated as needed.

  The vehicle sensor 50 includes a plurality of sensors for detecting various behaviors of the host vehicle. For example, the vehicle sensor 50 includes a vehicle speed sensor that detects the speed (vehicle speed) of the host vehicle, a wheel speed sensor that detects the speed of each wheel of the host vehicle, a longitudinal acceleration sensor that detects the acceleration / deceleration of the host vehicle, A lateral acceleration sensor that detects the lateral acceleration of the vehicle, a yaw rate sensor that detects the yaw rate of the host vehicle, an orientation sensor that detects the direction of the host vehicle, a gradient sensor that detects the slope of the host vehicle, and the like are provided.

  The vehicle sensor 50 includes a plurality of sensors that detect operation amounts of various operation devices. For example, the vehicle sensor 50 includes an accelerator pedal sensor that detects an amount of depression (opening) of an accelerator pedal, a steering angle sensor that detects an operation amount (steering angle) of a steering wheel, a torque sensor that detects steering torque, A brake pedal sensor that detects the amount of depression of the brake pedal, a shift sensor that detects the position of the shift lever, and an angle at which a steering mechanism of a steering device 73 described later drives and controls a wheel (steered wheel) (that is, a steering angle). Is provided with a turning angle sensor or the like that detects an amount (for example, rack stroke amount).

  The EPS 61 is a so-called electric power steering device. The EPS 61 includes an EPS / ECU (not shown), and changes the direction of the wheels (steering wheels) by controlling a steering device 73 described later in accordance with a control command output from the ECU 10 described in detail later.

  The VSA 62 is a so-called vehicle behavior stabilization control device. The VSA 62 is equipped with a VSA / ECU (not shown) and suppresses the ABS function that prevents the wheel from being locked during braking operation, the TCS (traction control system) function that prevents the wheel from slipping during acceleration, and the like, and the side slip during turning. And a function of performing emergency braking control regardless of the driver's braking operation when the host vehicle collides. In order to realize these functions, the VSA 62 assists in stabilizing the behavior of the vehicle by adjusting a brake fluid pressure generated by an ESB 64 described later.

  Specifically, the VSA 62 controls a brake device 72 (described later) based on the vehicle speed, steering angle, yaw rate, lateral acceleration, and the like detected by the vehicle speed sensor, the steering angle sensor, the yaw rate sensor, and the lateral acceleration sensor. Specifically, by controlling the hydraulic unit that supplies the brake hydraulic pressure to the brake cylinders for the front, rear, left, and right wheels, the braking force of each wheel is individually controlled to improve running stability.

  The AWD 63 is a so-called four-wheel drive force free control system and functions as a drive force distribution control unit. That is, the AWD 63 includes an AWD / ECU (not shown) and freely controls the distribution of driving force between the front and rear wheels and the left and right front wheels or the distribution of driving force between the left and right rear wheels. Specifically, the AWD 63 is based on the vehicle speed sensor, the steering angle sensor, the yaw rate sensor, and the lateral acceleration sensor, based on the vehicle speed, the steering angle, the yaw rate, the lateral acceleration, etc. By controlling the drive motor and the like, the distribution of the driving force between the front, rear, left and right wheels is changed.

  Further, the AWD 63 functioning as a driving force distribution control unit, as will be described in detail later, when the operation switching control unit 12 performs switching from automatic operation control to manual operation control, When the condition is not satisfied, the automatic driving control is maintained, and the driving force distribution cooperative control is executed so as to maintain the traveling locus of the host vehicle. Thereafter, when the vehicle satisfies a predetermined traveling stability condition, switching to manual operation control is executed. This will be described in detail later.

  The ESB 64 includes an ESB / ECU (not shown), and generates braking force on the wheels by controlling a brake device 72 described later according to a control command output from the ECU 10 described in detail later.

  The driving force output device 71 includes an electric motor that is a driving source of the host vehicle. The driving force output device 71 generates a traveling driving force (torque) for the host vehicle to travel in accordance with a control command output from the ECU 10 described in detail later, and transmits the traveling driving force (torque) to each wheel via a transmission.

  The brake device 72 is composed of, for example, an electric servo brake that uses a hydraulic brake together. The brake device 72 brakes the wheel in accordance with a control command output from the ECU 10 described in detail later.

  The steering device 73 is controlled by the above-described EPS 61 to change the direction of the wheels (steering wheels).

Next, the ECU 10 provided in the vehicle control system 1 according to the present embodiment will be described in detail.
As shown in FIG. 1, the ECU 10 includes an automatic operation control unit 11, an operation switching control unit 12, a manual operation control unit 13, and a travel stability determination unit 14.

  The automatic operation control unit 11 includes a first CPU 111 and a second CPU 112.

  The first CPU 111 includes an external environment recognition unit 113, a vehicle position recognition unit 114, an action plan generation unit 115, and an abnormality determination unit 116.

  The external world recognition unit 113 recognizes an external object (recognition target object) and its position based on various information acquired by the external environment sensing device 20 described above. Specifically, the external environment recognition unit 113 recognizes obstacles, road shapes, traffic lights, guardrails, utility poles, surrounding vehicles (including traveling conditions such as speed and acceleration, parking conditions), lane marks, pedestrians, and the like. Recognize the position of

  The own vehicle position recognizing unit 114 recognizes the current position and posture of the own vehicle based on the position information of the own vehicle measured by the navigation device 40 and various sensor information detected by the vehicle sensor 50 described above. To do. Specifically, the vehicle position recognition unit 114 recognizes the traveling lane in which the host vehicle is traveling by comparing the map information and the image acquired by the camera 21, and the host vehicle with respect to the traveling lane. Recognize the relative position and posture.

  The action plan generation unit 115 generates an action plan for automatic driving until the host vehicle reaches a destination or the like. Specifically, the action plan generation unit 115 determines the situation of the host vehicle and the surrounding area based on the external environment information recognized by the external environment recognition unit 113 and the own vehicle position information recognized by the own vehicle position recognition unit 114. While responding to the situation, an action plan for automatic driving is generated so that the route determined by the route determination unit 42 can be traveled.

  Specifically, the action plan generation unit 115 generates a target track on which the host vehicle will travel in the future. More specifically, the action plan generation unit 115 generates a plurality of target trajectory candidates, and selects an optimal target trajectory at that time from the viewpoint of safety and efficiency. In addition, when the abnormality determination unit 116, which will be described in detail later, determines that the occupant or the host vehicle is in an abnormal state, the action plan generation unit 115, for example, moves the host vehicle to a safe position (emergency parking zone, An action plan for stopping at a roadside belt, a shoulder, a parking area, etc.) is generated.

  The abnormality determination unit 116 determines whether at least one of the driver and the host vehicle is in an abnormal state. The abnormal state of the driver is, for example, a deterioration of physical condition, and includes a state in which an occupant is sleeping or an unconscious state due to illness or the like. The abnormal state of the host vehicle is a failure of the host vehicle.

  Specifically, the abnormality determination unit 116 determines an abnormal state of the driver by analyzing an image acquired by the driver monitor camera described above. In addition, the abnormality determination unit 116 displays the voice, vibration of the seat belt, or the like when the vehicle is forcibly switched from the automatic driving to the manual driving regardless of the driver's intention, for example, due to a failure of the host vehicle. If a driver's manual driving operation is not detected even though a warning is notified for a predetermined number of times, it is determined that the driver is in an abnormal state. The driver's manual driving operation is detected by the above-described steering wheel touch sensor, accelerator pedal sensor, brake pedal sensor, and the like.

  Moreover, the abnormality determination part 116 detects the presence or absence of the failure of the own vehicle based on the various sensor information acquired by the above-described vehicle sensor 50 or the like, and if the failure is detected, the own vehicle is in an abnormal state. Is determined.

  The second CPU 112 includes a vehicle control unit 117. The outside control information, the vehicle position information, the action plan, and the abnormality information acquired by the first CPU 111 are input to the vehicle control unit 117 that constitutes the second CPU 112.

  The vehicle control unit 117 starts / stops automatic driving according to the automatic driving start / stop signal input from the above-described automatic driving changeover switch. Further, the vehicle control unit 117 outputs a driving force via the above-described EPS 61, VSA 62, AWD 63, ESB 64, and the like so that the host vehicle travels at a target speed along the target track generated by the action plan generation unit 115. The device 71, the brake device 72, and the steering device 73 are controlled.

  The operation switching control unit 12 switches each operation mode between the automatic operation and the manual operation according to the signal input from the above-described automatic operation switch. For example, the operation switching control unit 12 switches the operation mode based on an operation for instructing acceleration, deceleration, or steering with respect to an accelerator pedal, a brake pedal, a steering wheel, or the like. In addition, the driving switching control unit 12 performs switching from automatic driving to manual driving in the vicinity of the planned end point of automatic driving set by the action plan generated by the action plan generating unit 115. When the abnormality determination unit 116 determines that the vehicle is in an abnormal state due to a failure of the host vehicle or the like, the operation switching control unit 12 avoids execution of automatic operation control and switches to manual operation control. Execute.

  The manual operation control unit 13 executes control necessary for traveling of the host vehicle by manual driving by the driver. The manual operation control unit 13 controls the driving force output device 71, the brake device 72, the steering device 73, and the like described above based on operations of the steering wheel, the accelerator pedal, the brake pedal, and the like by the driver.

  The traveling stability determination unit 14 determines whether or not the host vehicle satisfies the traveling stability condition. The traveling stability determination unit 14 includes a straight travel determination unit 141 and a grip determination unit 142. The traveling stability condition is that the straight travel determination unit 141, which will be described in detail later, determines that the straight travel performance is good and the grip determination unit 142 determines that the grip performance is good. In addition, the traveling stability determination unit 14 determines that the traveling stability of the host vehicle is good.

  The straight travel determination unit 141 determines the straight travel performance of the host vehicle. Specifically, the straight traveling determination unit 141 determines that the vehicle's tire turning angle (cutting angle) is equal to or smaller than a predetermined threshold and the vehicle's lateral acceleration is equal to or smaller than a predetermined threshold. It is determined that the straightness is good.

  Here, the turning angle (cutting angle) of the tire of the host vehicle is acquired by the above-described turning angle sensor, and the predetermined threshold value (turning angle threshold value) is a steering that maintains the straightness of the vehicle through experiments. The angle is preset. Further, the lateral acceleration of the host vehicle is acquired by the above-described lateral acceleration sensor, and the predetermined threshold (lateral acceleration threshold) is set in advance to a lateral acceleration at which the straightness of the vehicle is maintained through experiments.

  The grip determination unit 142 determines the grip performance of the tire of the host vehicle. Specifically, the grip determination unit 142 determines that the grip performance is good when the tire slip rate of each wheel of the host vehicle is equal to or less than a predetermined threshold.

  Here, the tire slip rate of each wheel of the host vehicle is calculated based on the steering angle and the wheel speed of each wheel. The steering angle is acquired by the above-described steering angle sensor, and the wheel speed of each wheel is acquired by each of the above-described wheel speed sensors. The predetermined threshold (tire slip ratio threshold) is set in advance to a tire slip ratio at which the straightness of the vehicle is maintained through experiments.

  Next, the operation switching control executed by the vehicle control system 1 of the present embodiment having the above-described configuration and during the turning of the vehicle will be described in detail with reference to FIG.

  Here, FIG. 2 is a flowchart showing the procedure of the process of the operation switching control during the turning of the vehicle. The operation switching control process shown in FIG. 2 is repeatedly executed at a predetermined cycle during the automatic operation control.

  In step S1, it is determined whether or not the host vehicle is under automatic driving control. If this determination is YES, the process proceeds to step S2, and if NO, this process ends.

  In step S2, it is determined whether or not there is a switch from automatic operation control to manual operation control. If this determination is YES, the process proceeds to step S3, and if NO, this process ends.

  In step S3, it is determined whether or not the host vehicle satisfies the above-described traveling stability condition. If this determination is YES, the process proceeds to step S4, and if NO, the process proceeds to step S5.

  In step S4, the steering control by EPS 61 is set as manual operation control, and the driving force distribution control by AWD 63 performs switching to partial manual operation control to maintain automatic operation control. At this time, the driving force distribution is automatically cooperatively controlled so as to maintain the traveling locus of the host vehicle. Then, it returns to step S3.

  In step S5, switching to full manual operation control in which driving force distribution control by the AWD 63 is also manual operation control is executed. After execution, this process is terminated.

  The vehicle control system 1 according to the present embodiment described above has the following effects.

In the vehicle control system according to the present embodiment, when switching from automatic driving control to manual driving control is performed while the vehicle is turning, the driving stability determination unit determines that the vehicle does not satisfy the driving stability condition. In this case, the steering control of the vehicle is set to manual driving control, while the driving force distribution control of the vehicle is switched to partial manual driving control which is automatic driving control.
As a result, for example, when the vehicle is turning on a low μ road surface or the like, when switching from automatic driving control to manual driving control is performed, it is not suitable as a situation in which the driver takes over driving, and the driving stability of the vehicle When it becomes difficult to maintain this, switching to automatic operation control is restricted. Specifically, manual operation of the steering control of the vehicle is permitted, while the driving force distribution control of the vehicle is maintained in an automatic driving state (partial manual driving control). Therefore, the running stability of the vehicle can be maintained even when switching from automatic driving to manual driving while the vehicle is turning.

Further, in the vehicle control system according to the present embodiment, when the driving stability determining unit determines that the driving stability condition is satisfied after the partial switching to the manual driving control is performed, the driving force distribution control is also performed. Switch to full manual operation control for manual operation control.
As described above, according to the present embodiment, it is possible to perform the switching from the automatic driving to the manual driving in a stepwise manner while turning the vehicle while maintaining the running stability of the vehicle, and to assist the driving control at the time of the switching transition. .

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

  For example, in the above-described embodiment, an electric vehicle is described as an example of a vehicle on which the vehicle control system 1 is mounted. However, the vehicle control system 1 may be mounted on an engine vehicle, a hybrid vehicle, a fuel cell vehicle, or the like.

1 Vehicle control system 10 ECU
DESCRIPTION OF SYMBOLS 11 Automatic driving | operation control part 12 Driving | operation switching control part 13 Manual driving | operation control part 14 Driving | running | working stability determination part 141 Straight travel determination part 142 Grip determination part 50 Vehicle sensor 63 AWD
61 EPS

Claims (5)

An automatic operation control unit for automatically controlling the vehicle;
A manual operation control unit that manually controls the vehicle according to the operation of the driver;
An operation switching control unit that switches between the automatic operation control and the manual operation control, and a vehicle control system comprising:
A travel stability determination unit that determines whether or not the vehicle satisfies a travel stability condition;
The operation switching control unit
When performing the switching from the automatic driving control to the manual driving control during the turning of the vehicle, if the driving stability determining unit determines that the driving stability condition is not satisfied, the steering of the vehicle A vehicle control system that performs switching to partial manual operation control in which the driving force distribution control of the vehicle is automatic operation control while the control is manual operation control. The operation switching control unit
After executing the switching to the partial manual operation control, when the travel stability determination unit determines that the travel stability condition is satisfied, the driving force distribution control is also set to manual operation control. The vehicle control system according to claim 1, wherein switching to control is executed. The traveling stability determination unit
A straight-ahead determination unit that determines straight-ahead performance of the vehicle;
A grip determination unit that determines grip performance of the tire of the vehicle,
When the straight travel determination unit determines that the straight travel performance is good and the grip determination unit determines that the grip performance is good, it determines that the running stability of the vehicle is good. The vehicle control system according to claim 1 or 2.   The straight-running determination unit determines that the straight-running performance is good when a tire turning angle of the vehicle is equal to or smaller than a predetermined threshold and a lateral acceleration of the vehicle is equal to or smaller than a predetermined threshold. The vehicle control system described in 1.   5. The vehicle control system according to claim 3, wherein the grip determination unit determines that the grip performance is good when a tire slip ratio of each wheel of the vehicle is equal to or less than a predetermined threshold value.

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