Vehicle control method and vehicle control device

Abstract

To suppress a passenger's sense of discomfort and deterioration of ride comfort through control to generate a yaw rate for allowing an own vehicle to travel along a target travel trajectory, based on a braking and driving force difference.SOLUTION: A vehicle control method controls a turning motion of an own vehicle by: acquiring traveling road information about a traveling road on which an own vehicle travels (S1); calculating a target travel trajectory and a target vehicle speed of the own vehicle based on the traveling road information (S2); calculating a target yaw rate for allowing the own vehicle to travel along the target travel trajectory at the target vehicle speed (S3); detecting or estimating an actual yaw rate generated in the own vehicle (S4); calculating a yaw rate expected value based on a steering angle and a vehicle speed of the own vehicle (S5); determining whether or not tire force of a tire of the own vehicle is saturated based on a deviation between the yaw rate expected value and the actual yaw rate (S6); and generating a braking and driving force difference on each wheel based on the deviation between the target yaw rate and the actual yaw rate when determining that the tire force is saturated (S7).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle control method and a vehicle control device. [Background technology]

[0002] The vehicle motion control device described in Patent Document 1 acquires a standard motion state quantity required to cause the vehicle to trace a target driving path, acquires a target motion state quantity required to generate a yaw moment to counteract unstable vehicle behavior based on the vehicle motion state quantity acquired from a vehicle motion state detection unit and the standard motion state quantity, calculates a target braking force based on the target driving path and the target motion state quantity, and causes a braking device to generate the target braking force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 132134 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the tire forces of the vehicle's tires are not saturated, generating a yaw moment due to steering rather than a yaw moment due to the difference in braking / driving force between the wheels will result in less discomfort for the occupants and a more comfortable ride. The present invention aims to prevent passengers from feeling uncomfortable or the ride comfort from being adversely affected by control that generates a yaw rate for driving a vehicle along a target driving trajectory using a difference between braking and driving forces. [Means for solving the problem]

[0005] In one aspect of the present invention, a vehicle control method acquires route information for a route along which the vehicle is traveling, calculates a target traveling trajectory and target vehicle speed for the vehicle based on the route information, calculates a target yaw rate for traveling at the target vehicle speed along the target traveling trajectory, detects or estimates the actual yaw rate occurring in the vehicle, calculates an expected yaw rate based on the steering angle and vehicle speed of the vehicle, determines whether the tire force of the vehicle's tires is saturated based on the deviation between the expected yaw rate and the actual yaw rate, and if it is determined that the tire force is saturated, controls the turning movement of the vehicle by generating a difference in braking / driving force of each wheel based on the deviation between the target yaw rate and the actual yaw rate. [Effects of the Invention]

[0006] According to the present invention, it is possible to prevent passengers from feeling uncomfortable or the ride comfort from being adversely affected by control that generates a yaw rate for driving the vehicle along a target driving trajectory using the difference between braking and driving forces. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of a schematic configuration of a vehicle control device according to an embodiment; [Figure 2] FIG. 2 is a block diagram illustrating an example of a functional configuration of a controller according to the first embodiment. [Figure 3] FIG. 2 is a block diagram illustrating an example of a functional configuration of a braking / driving control calculation unit. [Figure 4] 3 is a flowchart illustrating an example of a vehicle control method according to the first embodiment. [Figure 5] FIG. 10 is a block diagram illustrating an example of a functional configuration of a controller according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the embodiments of the present invention shown below are examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the structure, arrangement, etc. of component parts to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0009] (First embodiment) (composition) FIG. 1 is a diagram illustrating a schematic configuration example of a vehicle control device according to an embodiment. The host vehicle 1 includes a vehicle control device 10 that controls at least the driving force or braking force of the host vehicle 1. For example, the vehicle control device 10 may execute autonomous driving control, which controls the steering angle, driving force, and braking force of the host vehicle 1 based on the driving environment around the host vehicle 1, to automatically drive the host vehicle 1 without the involvement of a driver. Furthermore, for example, the vehicle control device 10 may execute driving assistance control, which assists the driver in driving the host vehicle 1, by controlling at least one of the steering angle, driving force, and braking force of the host vehicle 1. The driving assistance control may include, for example, automatic braking, lane keeping control, automatic speed control (for example, constant speed driving control, inter-vehicle control that maintains a target inter-vehicle distance from a leading vehicle, or leading vehicle following control), etc.

[0010] The vehicle control device 10 includes an ambient environment sensor 11, a vehicle sensor 12, a positioning device 13, a map database (map DB) 14, a navigation system 15, a controller 16, a steering actuator 17, an accelerator actuator 18, and a brake actuator 19.

[0011] The surrounding environment sensor 11 detects objects within a predetermined distance range from the host vehicle 1. The surrounding environment sensor 11 detects the surrounding environment of the host vehicle 1, such as the relative position of the host vehicle 1 and objects present around the host vehicle 1, the distance between the host vehicle 1 and the objects, and the direction in which the objects are present. The surrounding environment sensor 11 may include, for example, a camera that captures images of the surrounding environment of the host vehicle 1. The surrounding environment sensor 11 may also include a distance measuring device such as a laser range finder, radar, LiDAR (Light Detection and Ranging), or sonar. The surrounding environment sensor 11 outputs surrounding environment information, which is information on the detected surrounding environment of the host vehicle 1, to the controller 16.

[0012] The vehicle sensor 12 detects various information (vehicle information) of the host vehicle 1. For example, the vehicle sensor 12 may include a vehicle speed sensor that detects the vehicle speed V of the host vehicle 1, an acceleration sensor that detects the acceleration (including deceleration) of the host vehicle 1 in three axial directions, a steering angle sensor that detects the front wheel steering angle δf and the rear wheel steering angle δr of the host vehicle 1, and a yaw rate sensor that detects the yaw rate occurring in the host vehicle 1. The vehicle sensor 12 outputs vehicle state information to the controller 16. Note that if the host vehicle 1 does not have a rear wheel steering mechanism, the steering angle sensor detects only the front wheel steering angle δf. In the following description, the front wheel steering angle δf and the rear wheel steering angle δr may be collectively referred to as the "steering angle δ." The yaw rate detected by the yaw rate sensor may be referred to as the "actual yaw rate γa."

[0013] The positioning device 13 measures the current position of the vehicle 1. The positioning device 13 includes, for example, a Global Navigation System (GNSS) receiver. The GNSS receiver is, for example, a Global Positioning System (GPS) receiver, and receives radio waves from multiple navigation satellites to measure the current position of the vehicle 1. The positioning device 13 may also include an inertial navigation system. The positioning device 13 outputs current position information, which is information on the measured current position and attitude, to the controller 16. Map data is stored in the map database 14. The map data stored in the map database 14 may be high-precision map data suitable for use as map data for navigation or maps for automatic driving, for example.

[0014] The navigation system 15 recognizes the current position of the vehicle 1 using the positioning device 13 and obtains map information for the current position from the map database 14. The navigation system 15 sets a driving route to the destination input by the occupant and provides route guidance to the occupant along this driving route. The navigation system 15 also outputs information about the set driving route to the controller 16. When performing autonomous driving control, the controller 16 automatically drives the vehicle 1 so that the vehicle 1 travels along the driving route set by the navigation system 15.

[0015] Steering actuator 17 controls the steering direction and steering amount of the steering mechanism of vehicle 1 in response to a control signal from controller 16. For example, if the steering mechanism of vehicle 1 is equipped with a steer-by-wire system in which the steering wheel and steered wheels are mechanically separated, steering actuator 17 may be a steering motor that generates a steering force to turn the steered wheels. Also, for example, if the steering mechanism is an electric power steering system that applies a steering assist force to assist the driver in steering the steering wheel, steering actuator 17 may be a steering assist motor that generates a steering assist force. The accelerator actuator 18 controls the accelerator opening of the drive device, which is an engine or a drive motor, in response to a control signal from the controller 16. The brake actuator 19 operates the braking device in response to a control signal from the controller 16.

[0016] The controller 16 is an electronic control unit (ECU) that performs autonomous driving control and driving assistance control of the host vehicle 1. The controller 16 includes a processor 16a and peripheral components such as a storage device 16b. The processor 16a may be, for example, a central processing unit (CPU) or a micro-processing unit (MPU). The storage device 16b may include a semiconductor storage device, a magnetic storage device, an optical storage device, etc. The storage device 16b may include memories such as a register, a cache memory, and a read-only memory (ROM) and a random access memory (RAM) used as a main storage device. The functions of the controller 16 described below are realized, for example, by the processor 16a executing a computer program stored in the storage device 16b.

[0017] The controller 16 may be formed by dedicated hardware for executing each of the information processes described below. For example, the controller 16 may include a functional logic circuit configured in a general-purpose semiconductor integrated circuit, such as a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0018] 2 is a block diagram of an example of the functional configuration of the controller 16 in the first embodiment. In the first embodiment, the functional configuration of the controller 16 when the controller 16 drives the host vehicle 1 using autonomous driving control will be described. The controller 16 includes a target trajectory calculation unit 30, a target calculation unit 31, a vehicle control calculation unit 32, a yaw rate calculation unit 33, an intervention determination unit 34, and a braking / driving control calculation unit 35.

[0019] The target trajectory calculation unit 30 acquires route information for the route along which the vehicle 1 is traveling. For example, the target trajectory calculation unit 30 acquires, as route information, ambient environment information acquired from the ambient environment sensor 11 and high-precision map data from the map database 14. Based on the acquired route information, the route set by the navigation system 15, and the current position measured by the positioning device 13, the target trajectory calculation unit 30 calculates a target traveling trajectory and a target vehicle speed as control targets for autonomous driving control for the vehicle 1 to travel along the route.

[0020] For example, the target trajectory calculation unit 30 may generate a route space map that represents the route around the host vehicle 1 and the presence or absence of objects, and a risk map that quantifies the risk of the driving field, and calculate a target driving trajectory and target vehicle speed for the host vehicle 1 based on the motion characteristics of the host vehicle 1, vehicle state information, the route space map, and the risk map. For example, the target trajectory calculation unit 30 may calculate a target vehicle speed profile that represents the target vehicle speed at a sequence of points on the target driving trajectory.

[0021] The target calculation unit 31 calculates the target longitudinal force Fxt, target lateral force Fyt, target yaw rate γt, target sideslip angle βt, and target yaw moment Mzt required for the host vehicle 1 to travel at the target vehicle speed along the target travel path. For example, the target calculation unit 31 may calculate the longitudinal force and lateral force required for the mass point of the host vehicle 1 to travel at the target vehicle speed along the target travel trajectory as the target longitudinal force Fxt and the target lateral force Fyt, respectively. Also, the target calculation unit 31 may calculate the target yaw rate γt, the target sideslip angle βt, and the target yaw moment Mzt based on the following equations (1) to (9).

[0022]

number

[0023] In equations (1) to (9), m is the weight of the host vehicle 1, Iz is the yaw moment of inertia, l is the wheel base, lf and lr are the distances from the center of gravity of the host vehicle 1 to the front and rear axles, Cf and Cr are the equivalent cornering powers of the front and rear wheels, A is the stability factor, and s is the Laplace operator.

[0024] The vehicle control calculation unit 32 calculates the target steering angle and the target braking / driving force of each wheel based on the target longitudinal force Fxt, target lateral force Fyt, target yaw rate γt, target sideslip angle βt, and target yaw moment Mzt calculated by the target calculation unit 31. For example, the vehicle control calculation unit 32 calculates a target steering angle for realizing a target yaw rate γt and a target braking / driving force for realizing a target longitudinal force Fxt.

[0025] The vehicle control calculation unit 32 may distribute the control amount for achieving the target yaw rate γt to braking force, steering force, and driving force. In this case, in order to achieve the target yaw rate γt, not only the steering angle δ but also the addition of a yaw moment due to the braking / driving force of each wheel and the influence of wheel load fluctuations may be actively used, and for this purpose, information such as the target sideslip angle βt and the target yaw moment Mzt may also be used. The vehicle control calculation unit 32 controls the steering actuator so that the steering angle δ of the steered wheels of the host vehicle 1 becomes the target steering angle. In addition, the vehicle control calculation unit 32 controls the accelerator actuator 18 or the brake actuator 19 so that the target braking / driving force is generated at each wheel.

[0026] The yaw rate calculation unit 33 calculates a yaw rate expected value γe, which is an expected value of a yaw rate that can occur in the host vehicle 1 when it is assumed that the tire characteristics of each wheel are linear, based on the vehicle speed V and steering angle δ detected by the vehicle sensor 12. For example, the yaw rate calculation unit 33 may calculate the yaw rate expected value γe based on the following equation (10) that follows a two-wheel model of the vehicle.

[0027]

number

[0028] The intervention determination unit 34 determines whether to perform intervention control to generate a yaw moment of the host vehicle 1 by using the braking / driving force difference of each wheel based on the deviation |γe-γa| between the yaw rate expected value γe and the actual yaw rate γa. Here, the intervention control may be, for example, control to generate a yaw moment by using the braking / driving force difference of each wheel to eliminate the deviation of the actual yaw rate γa from the target yaw rate γt required for the host vehicle 1 to travel along the target travel trajectory. Alternatively, for example, the intervention control may be control to generate a yaw moment by using the braking / driving force difference of each wheel to stabilize the vehicle behavior of the host vehicle 1.

[0029] For example, the intervention determination unit 34 may determine whether the tire force of the tires of the host vehicle 1 is saturated based on the deviation |γe-γa|, and determine to perform intervention control if the tire force is saturated. Here, "tire force is saturated" may mean, for example, a state in which cornering power is saturated with respect to an increase in the tire slip angle. For example, the intervention determination unit 34 may determine that the tire force is saturated if the deviation |γe-γa| is equal to or greater than a predetermined threshold. This predetermined threshold may be set to a value that suits the host vehicle 1, for example, through experiments or simulations. The intervention determination unit 34 outputs the determination result of whether to perform intervention control to the braking / driving control calculation unit 35.

[0030] When the intervention determination unit 34 determines that intervention control should be performed, the braking / driving control calculation unit 35 performs intervention control to generate a yaw moment by using the braking / driving force difference between the wheels to eliminate the deviation of the actual yaw rate γa from the target yaw rate γt. For example, the braking / driving control calculation unit 35 may generate the yaw moment by using the braking / driving force difference between the wheels using conventional electronic stability control (ESC).

[0031] 3 is a block diagram showing an example of the functional configuration of braking / driving control calculation unit 35. Braking / driving control calculation unit 35 includes a yaw rate deviation calculation unit 40, a sideslip angle deviation calculation unit 41, a sideslip angle velocity calculation unit 42, controllers 43, 44, and 45, an adder 46, and a braking / driving command calculation unit 47. A yaw rate deviation calculation unit 40 calculates the yaw rate deviation Δγ of the actual yaw rate γa relative to the target yaw rate γt. A sideslip angle deviation calculation unit 41 estimates the sideslip angle deviation Δβ of the actual sideslip angle relative to the target sideslip angle based on the actual yaw rate γa, steering angle δ, and vehicle speed V. A sideslip angle velocity calculation unit 42 estimates the sideslip angle velocity dβ, which is the derivative of the actual sideslip angle, based on the actual yaw rate γa, vehicle speed V, and lateral acceleration Gy.

[0032] Controllers 43, 44, and 45 calculate the first yaw moment component Mz1, the second yaw moment component Mz2, and the third yaw moment component Mz3, respectively, by at least one of proportional action control (I control), integral action control (P control), and differential action control (D control) for the yaw rate deviation Δγ, the sideslip angle deviation Δβ, and the sideslip angular velocity dβ. The gains of these I control, P control, and D control may be variable gains that change according to the estimated value of the road surface friction coefficient μ and the vehicle speed. An adder 46 calculates the sum of the first to third yaw moment components Mz1 to Mz3 as the braking / driving control target yaw moment Mztv=Mz1+Mz2+Mz3.

[0033] The braking / driving control calculation unit 35 calculates a target left front wheel braking / driving force FxFL, a target right front wheel braking / driving force FxFR, a target left rear wheel braking / driving force FxRL, and a target right rear wheel braking / driving force FxRR for generating a braking / driving control target yaw moment Mztv in the host vehicle 1. For example, the braking / driving control calculation unit 35 may calculate the target left front wheel braking / driving force FxFL, the target right front wheel braking / driving force FxFR, the target left rear wheel braking / driving force FxRL, and the target right rear wheel braking / driving force FxRR based on the relational expression in the following equation (11).

[0034] Mztv=(FxFL-FxFR)×Tf / 2+(FxRL-FxRR)×Tr / 2 …(11) In equation (11), Tf and Tr are the treads of the front and rear wheels, respectively. For example, when a counterclockwise yaw moment is generated only by the braking force of the left front wheel and the left rear wheel, the following equation (12) is obtained from the above equation (11).

[0035] Mztv=κ×Fx×Tf / 2+(1-κ)Fx×Tr / 2 …(12) In equation (12), κ and (1-κ) are the braking force distributions to the front and rear wheels. By rearranging equation (12) above, the left front wheel braking force FxFL and the left rear wheel braking force FxRL can be calculated based on the following equations (13) to (15). FxFL = κ × Fx … (13) FxRL=(1-κ)×Fx …(14) Fx=2×Mztv / {κ×Tf+(1-κ)×Tr}…(15)

[0036] The braking / driving control calculation unit 35 controls the accelerator actuator 18 or the brake actuator 19 so that the left front wheel, right front wheel, left rear wheel, and right rear wheel generate the target left front wheel braking / driving force FxFL, target right front wheel braking / driving force FxFR, target left rear wheel braking / driving force FxRL, and target right rear wheel braking / driving force FxRR, respectively. After starting the intervention control, the braking / driving control calculation unit 35 determines whether the actual traveling trajectory of the host vehicle 1 has converged to the target traveling trajectory. If it is determined that the actual traveling trajectory of the host vehicle 1 has converged to the target traveling trajectory, the braking / driving control calculation unit 35 ends the intervention control.

[0037] For example, the braking / driving control calculation unit 35 may determine that the actual traveling trajectory of the host vehicle 1 has converged to the target traveling trajectory when the yaw rate deviation Δγ, the sideslip angle deviation Δβ, and the lateral acceleration Gy are each less than a threshold value. Alternatively, for example, the braking / driving control calculation unit 35 may determine that the actual traveling trajectory of the host vehicle 1 has converged to the target traveling trajectory when the position deviation of the current position of the host vehicle 1 from the target traveling trajectory is less than a threshold value.

[0038] (operation) 4 is a flowchart of an example of the vehicle control method of the first embodiment. In step S1, the target trajectory calculation unit 30 acquires route information of the route along which the host vehicle 1 is traveling. In step S2, the target trajectory calculation unit 30 calculates a target traveling route and a target vehicle speed. In step S3, the target calculation unit 31 calculates the target yaw rate γt. In step S4, the vehicle sensor 12 detects the actual yaw rate γa of the host vehicle 1.

[0039] In step S5, the yaw rate calculation unit 33 calculates the yaw rate expected value γe based on the vehicle speed V detected by the vehicle sensor 12 and the steering angle δ. In step S6, the intervention determination unit 34 determines whether the tire force of the tires of the host vehicle 1 is saturated. If the tire force is not saturated (step S6: N), the process ends. In this case, intervention control is not executed. If the tire force is saturated (step S6: Y), the process proceeds to step S7. In step S7, the braking / driving control calculation unit 35 performs intervention control. That is, it generates a braking / driving force difference for each wheel based on the deviation between the target yaw rate γt and the actual yaw rate γa. Then, the process ends.

[0040] (Second embodiment) In the second embodiment, a functional configuration of the controller 16 will be described for the case where the host vehicle 1 is being manually driven by a driver. The host vehicle 1 may be a manually driven vehicle that does not have an autonomous driving function. In this case, for example, the controller 16 may execute lane keeping control to control the steering of the host vehicle 1 so that the host vehicle 1 does not deviate from the driving lane. The controller may also perform automatic speed control (constant speed control, inter-vehicle distance control, and preceding vehicle following control) to automatically adjust the traveling speed of the host vehicle 1.

[0041] 5 is a block diagram showing an example of the functional configuration of the controller 16 in the second embodiment. The controller 16 in the second embodiment has a functional configuration similar to that in the first embodiment. Therefore, the same or similar components are denoted by the same reference numerals. When the vehicle 1 is being manually driven by the driver, the target trajectory calculation unit 30 recognizes the lane boundaries of the lane on which the vehicle 1 is traveling. For example, the target trajectory calculation unit 30 may recognize lane boundaries based on images captured by a camera of the vehicle sensor 12 or measurement results from a distance measurement device.

[0042] Furthermore, for example, the target trajectory calculation unit 30 may recognize lane boundaries based on the measurement results from the positioning device 13 and high-precision map data in the map database 14. The target trajectory calculation unit 30 calculates a target driving trajectory based on the recognized lane boundary. For example, the target trajectory calculation unit 30 may calculate a target driving trajectory that passes through the lane center position based on the left and right lane boundaries, or may calculate a target driving trajectory that passes through a position that is a predetermined distance away from either the left or right lane boundary. The target trajectory calculation unit 30 may set the target vehicle speed based on the amount of accelerator pedal operation and the amount of brake pedal operation by the driver. The target trajectory calculation unit 30 may also set the current vehicle speed of the host vehicle 1 as the target speed.

[0043] When the vehicle control device 10 is assisting the driver in steering operations through lane keeping control, the target trajectory calculation unit 30 may set a trajectory that serves as a target for the driving trajectory of the vehicle 1 in lane keeping control as the target driving trajectory. In lane keeping control, lane boundaries of the lane in which the vehicle 1 is traveling may be recognized, and a target trajectory of the lane keeping control may be calculated based on the recognized lane boundaries. The lane boundaries may be recognized based on images captured by the camera of the vehicle sensor 12 or measurement results from a distance measuring device, or may be recognized based on measurement results from the positioning device 13 and high-precision map data in the map database 14.

[0044] Furthermore, when the vehicle control device 10 assists the driver in steering operation by automatic speed control, the target vehicle speed may be set as the target vehicle speed for the traveling speed of the host vehicle 1 in the automatic speed control. For example, the target vehicle speed of the constant speed cruise control may be a preset set speed or speed limit. Also, for example, the target vehicle speed of the vehicle distance control or the preceding vehicle following control may be set so that the inter-vehicle distance between the host vehicle 1 and the preceding vehicle becomes a target inter-vehicle distance according to the vehicle speed, with the preset set speed or speed limit as the upper limit. The configurations and processing of the target calculation unit 31, yaw rate calculation unit 33, intervention determination unit 34, and braking / driving control calculation unit 35 are the same as those in the first embodiment.

[0045] (Effects of the embodiment) (1) The vehicle control device 10 acquires route information for the route along which the vehicle 1 is traveling, calculates a target travel trajectory and target vehicle speed for the vehicle 1 based on the route information, calculates a target yaw rate for traveling at the target vehicle speed along the target travel trajectory, detects or estimates the actual yaw rate occurring in the vehicle 1, calculates an expected yaw rate based on the steering angle and vehicle speed of the vehicle 1, determines whether the tire force of the tires of the vehicle 1 is saturated based on the deviation between the expected yaw rate and the actual yaw rate, and if it determines that the tire force is saturated, generates a difference between the braking and driving forces of each wheel based on the deviation between the target yaw rate and the actual yaw rate, thereby controlling the turning movement of the vehicle 1. This makes it possible to prevent occupants from feeling uncomfortable or the ride from becoming uncomfortable due to control that generates a yaw rate for traveling along the target travel trajectory using the braking and driving force difference.

[0046] (2) The controller 16 may calculate the yaw rate, assuming that the tire characteristics are linear, as the expected yaw rate value based on the steering angle, vehicle speed, and a two-wheel model of the vehicle. For example, the controller 16 may use a sensor-measured value for the steering angle. Also, for example, the controller 16 may use a sensor-measured value for the vehicle speed. This allows the expected yaw rate value to be calculated based on the steering angle and vehicle speed, which can be measured relatively easily.

[0047] (3) The controller 16 may determine that the tire force is saturated when the deviation between the expected yaw rate and the actual yaw rate is equal to or greater than a threshold value. This allows the controller 16 to properly determine whether the tire force is saturated. (4) The controller 16 may set a target driving trajectory based on the autonomous driving control while the autonomous driving control is being executed. When the host vehicle 1 is being driven manually, the controller 16 may recognize lane boundaries and set a target driving trajectory based on the recognized lane boundaries. This allows the controller 16 to appropriately determine the trajectory on which the host vehicle 1 should converge.

[0048] (5) The controller 16 may set the target vehicle speed based on the autonomous driving control while the autonomous driving control is being executed. When the host vehicle 1 is being manually driven, the target vehicle speed may be set based on the operation amount of the accelerator pedal and the brake pedal, the current vehicle speed may be set as the target vehicle speed, or the target vehicle speed may be set by automatic speed control. This allows the yaw rate required to converge the host vehicle 1 to the target driving trajectory to be calculated appropriately. (6) When the traveling trajectory of the host vehicle 1 has converged to the target traveling trajectory, the controller 16 may terminate the generation of the braking / driving force difference based on the deviation between the target yaw rate and the actual yaw rate. This makes it possible to suppress excessive intervention control after the host vehicle 1 has converged to the target traveling trajectory. [Explanation of symbols]

[0049] 1... host vehicle, 10... vehicle control device, 11... ambient environment sensor, 12... vehicle sensor, 13... positioning device, 14... map database, 15... navigation system, 16... controller, 16a... processor, 16b... storage device, 17... steering actuator, 18... accelerator actuator, 19... brake actuator, 30... target trajectory calculation unit, 31... target calculation unit, 32... vehicle control calculation unit, 33... yaw rate calculation unit, 34... intervention determination unit, 35... braking / driving control calculation unit, 40... yaw rate deviation calculation unit, 41... sideslip angle deviation calculation unit, 42... sideslip angle velocity calculation unit, 43 to 45... controller, 46... adder, 47... braking / driving command calculation unit

Claims

1. Acquires road information for the road on which the vehicle is traveling, Calculating a target driving trajectory and a target vehicle speed of the vehicle based on the road information; calculating a target yaw rate for traveling at the target vehicle speed along the target traveling trajectory; Detecting or estimating an actual yaw rate occurring in the host vehicle; calculating an expected yaw rate value based on the steering angle and vehicle speed of the host vehicle; determining whether or not tire force of the tires of the host vehicle is saturated based on a deviation between the expected yaw rate value and the actual yaw rate; when it is determined that the tire force is saturated, a braking / driving force difference is generated between each wheel based on a deviation between the target yaw rate and the actual yaw rate, thereby controlling the turning movement of the host vehicle. A vehicle control method comprising:

2. 2. The vehicle control method according to claim 1, wherein the yaw rate expected value is calculated based on the steering angle, the vehicle speed, and a two-wheel model of the vehicle, assuming that tire characteristics are linear.

3. 2. The vehicle control method according to claim 1, wherein a measurement value obtained by a sensor is used as the steering angle.

4. 2. The vehicle control method according to claim 1, wherein a measurement value obtained by a sensor is used as the vehicle speed.

5. 2. The vehicle control method according to claim 1, wherein the tire force is determined to be saturated when a deviation between the expected yaw rate value and the actual yaw rate is equal to or greater than a threshold value.

6. During execution of autonomous driving control, the target driving trajectory is set based on the autonomous driving control; When the host vehicle is being driven manually, a lane boundary is recognized, and the target driving trajectory is set based on the recognized lane boundary.

2. The vehicle control method according to claim 1.

7. During execution of autonomous driving control, the target vehicle speed is set based on the autonomous driving control; When the host vehicle is being manually driven, the target vehicle speed is set based on the operation amount of an accelerator pedal and a brake pedal, or the current vehicle speed is set as the target vehicle speed, or the target vehicle speed is set by automatic speed control.

2. The vehicle control method according to claim 1.

8. 2. The vehicle control method according to claim 1, wherein when the traveling trajectory of the host vehicle converges to the target traveling trajectory, generation of the braking / driving force difference based on the deviation between the target yaw rate and the actual yaw rate is terminated.

9. a sensor for detecting an actual yaw rate occurring in the host vehicle or a process for estimating the actual yaw rate; a controller that executes a process of acquiring road information for a road along which the host vehicle will travel, a process of calculating a target travel trajectory and a target vehicle speed for the host vehicle based on the road information, a process of calculating a target yaw rate for traveling at the target vehicle speed along the target travel trajectory, a process of calculating an expected yaw rate based on the steering angle and vehicle speed of the host vehicle, a process of determining whether or not tire force of tires of the host vehicle is saturated based on a deviation between the expected yaw rate and the actual yaw rate, and a process of controlling turning movement of the host vehicle by generating a difference in braking / driving force of each wheel based on the deviation between the target yaw rate and the actual yaw rate when it is determined that the tire force is saturated; A vehicle control device comprising:

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