Vehicle control device, vehicle control method, and storage medium

Abstract

A vehicle control device, a vehicle control method, and a storage medium that can more reliably determine a steering abnormality of a vehicle. The vehicle control device includes: a generation unit that generates a target trajectory of the vehicle; a determination unit that determines whether a change speed of a target steering angle for following the target trajectory in a first time is equal to or greater than a first threshold value, and determines whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold value; and a mode determination unit that determines a driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode. When the mode determination unit has determined the driving mode of the vehicle to be the second driving mode, the mode determination unit changes the driving mode of the vehicle to the first driving mode both when the determination unit determines that the change speed of the target steering angle in the first time is equal to or greater than the first threshold value and when the determination unit determines that the change speed of the target steering angle in the second time is equal to or greater than the second threshold value.

Description

Technical Field

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

[0002] There is known a technique for preventing an accident by detecting an abnormal steering of a vehicle. For example, in Japanese Utility Model Laid-Open No. 63-114303, a steering control device is disclosed that detects a steering angle of a vehicle and determines that an abnormal steering has occurred when the steering angle is equal to or greater than a threshold value. Summary of the Invention

[0003] However, the steering control device described in Patent Document 1 determines an abnormal steering based on the steering angle of the vehicle and does not consider other parameters. Moreover, the steering control device described in Patent Document 1 uses a single threshold value to determine an abnormal steering of the vehicle, and thus there is a problem that the reliability of the determination is low.

[0004] The present invention has been made in view of such circumstances, and one of its objects is to provide a vehicle control device, a vehicle control method, and a storage medium that can more reliably determine an abnormal steering of a vehicle.

[0005] The vehicle control device of the present invention adopts the following configuration.

[0006] (1): A vehicle control device according to one aspect of the present invention includes: a generation unit that generates a target trajectory of the vehicle; a determination unit that determines whether a change speed of a target steering angle for following the target trajectory in a first time is equal to or greater than a first threshold value, and determines whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold value; and a mode determination unit that determines a driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode, and a task assigned to the driver in the second driving mode is lighter than that in the first driving mode. When the mode determination unit has determined the driving mode of the vehicle to be the second driving mode, when the determination unit determines that the change speed of the target steering angle in the first time is equal to or greater than the first threshold value and when it determines that the change speed of the target steering angle in the second time is equal to or greater than the second threshold value, the driving mode of the vehicle is changed to the first driving mode. The first time is a time longer than the second time, and the first threshold value is a value smaller than the second threshold value.

[0007] (2): A vehicle control device according to an aspect of the present invention includes: an acquisition unit that acquires a target steering angle for following a target track of a vehicle; a determination unit that determines whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold value, and determines whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold value; and a mode determination unit that determines a driving mode of the vehicle as any one of a plurality of driving modes including a first driving mode and a second driving mode, and a task assigned to the driver in the second driving mode is less severe than that in the first driving mode. When the driving mode of the vehicle is determined as the second driving mode by the mode determination unit, if the determination unit determines that the change speed of the target steering angle in the first time is equal to or greater than the first threshold value and the change speed of the target steering angle in the second time is equal to or greater than the second threshold value, the driving mode of the vehicle is changed to the first driving mode. The first time is a time longer than the second time, and the first threshold value is a value smaller than the second threshold value.

[0008] (3): Based on the aspect described in the above (1) or (2), the higher the vehicle speed of the vehicle is, the smaller the determination unit sets the first threshold value or the second threshold value.

[0009] (4): Based on any one of the aspects described in the above (1) to (3), when the vehicle speed of the vehicle is in a range from zero to a reference vehicle speed, the determination unit sets the first threshold value or the second threshold value to a specified value.

[0010] (5): Based on the aspect described in the above (4), the second driving mode includes a driving mode in which neither front monitoring of the vehicle nor gripping of the steering wheel of the vehicle is assigned to the driver, and an upper limit vehicle speed for the vehicle is set. The reference vehicle speed is the upper limit vehicle speed.

[0011] (6): Based on any one of the aspects described in the above (1) to (5), when the steering direction of the vehicle is a steering return direction, the determination unit sets the first threshold value or the second threshold value to be larger than when the steering direction is a steering increase direction.

[0012] (7): The vehicle control method according to an aspect of the present invention causes a vehicle control device to perform the following processes: obtain a target steering angle for following a target track of the vehicle; determine whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold, and determine whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold; determine the driving mode of the vehicle as any one of a plurality of driving modes including a first driving mode and a second driving mode, and the task assigned to the driver in the second driving mode is lighter than that in the first driving mode; in a case where the driving mode of the vehicle has been determined as the second driving mode, when it is determined that the change speed of the target steering angle in the first time is equal to or greater than the first threshold and when it is determined that the change speed of the target steering angle in the second time is equal to or greater than the second threshold, change the driving mode of the vehicle to the first driving mode, the first time is a time longer than the second time, and the first threshold is a value smaller than the second threshold.

[0013] (8): The vehicle control method according to an aspect of the present invention causes a vehicle control device to perform the following processes: obtain a target steering angle for following a target track of the vehicle; determine whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold, and determine whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold; determine the driving mode of the vehicle as any one of a plurality of driving modes including a first driving mode and a second driving mode, and the task assigned to the driver in the second driving mode is lighter than that in the first driving mode; in a case where the driving mode of the vehicle has been determined as the second driving mode, when it is determined that the change speed of the target steering angle in the first time is equal to or greater than the first threshold and the change speed of the target steering angle in the second time is equal to or greater than the second threshold, change the driving mode of the vehicle to the first driving mode, the first time is a time longer than the second time, and the first threshold is a value smaller than the second threshold.

[0014] (9): A storage medium according to an aspect of the present invention stores a program, wherein the program causes a processor of a vehicle control device to perform the following processing: obtaining a target steering angle for following a target trajectory of the vehicle; determining whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold, and determining whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold; determining the driving mode of the vehicle as any one of a plurality of driving modes including a first driving mode and a second driving mode, and the task assigned to the driver in the second driving mode is less severe than that in the first driving mode; when the driving mode of the vehicle has been determined as the second driving mode, when it is determined that the change speed of the target steering angle in the first time is equal to or greater than the first threshold and when it is determined that the change speed of the target steering angle in the second time is equal to or greater than the second threshold, changing the driving mode of the vehicle to the first driving mode, the first time is a time longer than the second time, and the first threshold is a value smaller than the second threshold.

[0015] (10): A storage medium according to an aspect of the present invention stores a program, wherein the program causes a processor of a vehicle control device to perform the following processing: obtaining a target steering angle for following a target trajectory of the vehicle; determining whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold, and determining whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold; determining the driving mode of the vehicle as any one of a plurality of driving modes including a first driving mode and a second driving mode, and the task assigned to the driver in the second driving mode is less severe than that in the first driving mode; when the driving mode of the vehicle has been determined as the second driving mode, when it is determined that the change speed of the target steering angle in the first time is equal to or greater than the first threshold and the change speed of the target steering angle in the second time is equal to or greater than the second threshold, changing the driving mode of the vehicle to the first driving mode, the first time is a time longer than the second time, and the first threshold is a value smaller than the second threshold.

[0016] According to the solutions of the above (1), (6), and (8), it is possible to more reliably determine the steering abnormality of the vehicle.

[0017] According to the solutions of the above (2), (7), and (9), it is possible to prevent misjudgment related to the steering abnormality of the vehicle.

[0018] According to the solutions of the above (3) and (4), it is possible to control the driving mode with low risk to the user.

[0019] According to the solution of the above (5), it is possible to control the driving mode flexibly according to the steering direction. Description of the Drawings

[0020] Figure 1 It is a structural diagram of a vehicle system using the vehicle control device of the embodiment.

[0021] Figure 2 It is a functional structural diagram of the first control unit and the second control unit.

[0022] Figure 3 It is a diagram showing an example of the correspondence relationship between the driving mode, the control state of the own vehicle M, and the tasks.

[0023] Figure 4 It is a diagram showing the relationship between the vehicle speed at the time of increasing steering and the threshold value of the steering speed.

[0024] Figure 5 It is a diagram showing the relationship between the vehicle speed at the time of retracting steering and the threshold value of the steering speed.

[0025] Figure 6 It is a flowchart showing an example of the change process of the driving mode executed by the mode determination unit.

[0026] Figure 7 It is a flowchart showing another example of the change process of the driving mode executed by the mode determination unit. Detailed Embodiments

[0027] Hereinafter, embodiments of the vehicle control device, the vehicle control method, and the storage medium of the present invention will be described with reference to the drawings.

[0028] <First Embodiment>

[0029] [Overall Structure]

[0030] Figure 1 It is a structural diagram of the vehicle system 1 using the vehicle control device of the first embodiment. The vehicle equipped with the vehicle system 1 is, for example, a two-wheeled, three-wheeled, four-wheeled, etc. vehicle, and its drive source is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using the generated power generated by a generator connected to the internal combustion engine, or the discharge power of a secondary battery or a fuel cell.

[0031] The vehicle system 1 includes, for example, a camera 10, a radar device 12, a LIDAR (Light Detection and Ranging) 14, an object recognition device 16, a communication device 20, an HMI (Human Machine Interface) 30, vehicle sensors 40, a navigation device 50, an MPU (Map Positioning Unit) 60, a driving operation member 80, an autonomous driving control device 100, a driving force output device 200, a braking device 210, and a steering device 220. These devices and equipment are interconnected via multi-channel communication lines such as CAN (Controller Area Network) communication lines, serial communication lines, wireless communication networks, etc. Figure 1 The structure shown is just an example. A part of the structure can be omitted, or other structures can be added.

[0032] The camera 10 is, for example, a digital camera that uses a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The camera 10 is installed at an arbitrary position of the vehicle (hereinafter referred to as the host vehicle M) on which the vehicle system 1 is mounted. When shooting forward, the camera 10 is installed on the upper part of the windshield, the back of the in-vehicle rearview mirror, etc. The camera 10, for example, periodically and repeatedly shoots the surroundings of the host vehicle M. The camera 10 can also be a stereo camera.

[0033] The radar device 12 emits radio waves such as millimeter waves to the surroundings of the host vehicle M, and detects the radio waves (reflected waves) reflected by an object to at least detect the position (distance and azimuth) of the object. The radar device 12 is installed at an arbitrary position of the host vehicle M. The radar device 12 can also detect the position and speed of an object by the FM-CW (Frequency Modulated Continuous Wave) method.

[0034] The LIDAR 14 irradiates light (or an electromagnetic wave with a wavelength close to light) to the surroundings of the host vehicle M and measures the scattered light. The LIDAR 14 detects the distance to the object based on the time from light emission to light reception. The irradiated light is, for example, pulsed laser light. The LIDAR 14 is installed at an arbitrary position of the host vehicle M.

[0035] The object recognition device 16 performs sensor fusion processing on the detection results detected by a part or all of the camera 10, the radar device 12, and the LIDAR 14 to identify the position, type, speed, etc. of the object. The object recognition device 16 outputs the recognition result to the autonomous driving control device 100. The object recognition device 16 may directly output the detection results of the camera 10, the radar device 12, and the LIDAR 14 to the autonomous driving control device 100. The object recognition device 16 may also be omitted from the vehicle system 1.

[0036] The communication device 20 communicates with other vehicles existing in the vicinity of the host vehicle M or communicates with various server devices via a wireless base station, for example, using a cellular network, a Wi-Fi network, Bluetooth (registered trademark), DSRC (Dedicated Short Range Communication), etc.

[0037] The HMI 30 presents various information to the occupants of the host vehicle M and accepts input operations performed by the occupants. The HMI 30 includes various display devices, speakers, buzzers, touch panels, switches, buttons, etc.

[0038] The vehicle sensor 40 includes a vehicle speed sensor that detects the speed of the host vehicle M, an acceleration sensor that detects acceleration, a yaw rate sensor that detects the angular velocity about the vertical axis, an azimuth sensor that detects the orientation of the host vehicle M, etc.

[0039] The navigation device 50 includes, for example, a GNSS (Global Navigation Satellite System) receiver 51, a navigation HMI 52, and a route determination unit 53. The navigation device 50 stores the first map information 54 in a storage device such as an HDD (Hard Disk Drive) or a flash memory. The GNSS receiver 51 determines the position of the host vehicle M based on the signals received from GNSS satellites. The position of the host vehicle M can also be determined or supplemented by an INS (Inertial Navigation System) that utilizes the output of the vehicle sensor 40. The navigation HMI 52 includes a display device, a speaker, a touch panel, buttons, etc. Part or all of the navigation HMI 52 can be shared with the aforementioned HMI 30. The route determination unit 53 determines, for example, a route (hereinafter referred to as the on-map route) from the position of the host vehicle M determined by the GNSS receiver 51 (or an arbitrary input position) to the destination input by the occupant using the navigation HMI 52 with reference to the first map information 54. The first map information 54 is information that represents the road shape by showing the road segments and the nodes connected by the road segments, for example. The first map information 54 may also include information such as the curvature of the road and POI (Point Of Interest) information. The on-map route is output to the MPU 60. The navigation device 50 can also perform route guidance using the navigation HMI 52 based on the on-map route. The navigation device 50 can be implemented by, for example, the functions of a terminal device such as a smartphone or a tablet terminal held by the occupant. The navigation device 50 can also send the current position and the destination to the navigation server via the communication device 20 and obtain a route equivalent to the on-map route from the navigation server.

[0040] The MPU 60 includes, for example, a recommended lane determination unit 61 and stores the second map information 62 in a storage device such as an HDD or a flash memory. The recommended lane determination unit 61 divides the on-map route provided from the navigation device 50 into a plurality of blocks (for example, divided every 100 [m] in the vehicle traveling direction) and determines the recommended lane for each block with reference to the second map information 62. The recommended lane determination unit 61 makes a determination as to which lane from the left to drive in. When there is a branch point in the on-map route, the recommended lane determination unit 61 determines the recommended lane so that the host vehicle M can travel on a reasonable route for traveling to the branch destination.

[0041] The second map information 62 is map information with higher accuracy than the first map information 54. The second map information 62 includes, for example, information on the center of the lane or information on the boundary of the lane. The second map information 62 can include road information, traffic restriction information, address information (address, postal code), facility information, telephone number information, etc. The second map information 62 can be updated at any time by communicating with other devices via the communication device 20.

[0042] The driver monitoring camera 70 is, for example, a digital camera that uses a solid-state imaging device such as a CCD or CMOS. The driver monitoring camera 70 is installed at an arbitrary position in the vehicle M at a position and orientation capable of photographing the head of an occupant (hereinafter referred to as the driver) sitting in the driver's seat of the vehicle M from the front (in the orientation of photographing the face). For example, the driver monitoring camera 70 is installed above a display device provided at the center of the instrument panel of the vehicle M.

[0043] The driving operation member 80 includes, for example, an accelerator pedal, a brake pedal, a shift lever, and other operation members in addition to the steering wheel 82. A sensor for detecting the operation amount or the presence or absence of an operation is installed on the driving operation member 80, and the detection result is output to a part or all of the automatic driving control device 100, or the driving force output device 200, the braking device 210, and the steering device 220. The steering wheel 82 is an example of an "operation member that receives a steering operation performed by the driver". The operation member does not necessarily have to be circular, and may be in the form of an irregular steering device, a joystick, a button, or the like. A steering grip sensor 84 is installed on the steering wheel 82. The steering grip sensor 84 is implemented by a capacitance sensor or the like, and outputs a signal to the automatic driving control device 100 that can detect whether the driver is gripping the steering wheel 82 (which means contacting in a state where a force can be applied).

[0044] The automatic driving control device 100 includes, for example, a first control unit 120 and a second control unit 160. The first control unit 120 and the second control unit 160 are respectively implemented, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components can be implemented by hardware (including a circuitry unit) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or can be implemented through the cooperation of software and hardware. The program can be pre-stored in a storage device (a storage device having a non-transitory storage medium) such as an HDD or a flash memory of the automatic driving control device 100, or can be stored in a removable storage medium such as a DVD or a CD-ROM, and installed in the HDD or flash memory of the automatic driving control device 100 by being mounted on a driving device through the storage medium (non-transitory storage medium). The automatic driving control device 100 is an example of a "vehicle control device", and the combination of the action plan generation unit 140 and the second control unit 160 is an example of a "driving control unit".

[0045] Figure 2 It is a functional structure diagram of the first control unit 120 and the second control unit 160. The first control unit 120 includes, for example, an identification unit 130, an action plan generation unit 140, and a mode determination unit 150. The first control unit 120 implements functions based on AI (Artificial Intelligence) and functions based on a pre-given model in parallel, for example. For example, the function of "identifying an intersection" can be implemented by "parallelly executing the identification of an intersection based on deep learning, etc., and the identification based on pre-given conditions (the presence of signals, road signs, etc. capable of pattern matching), scoring both, and comprehensively evaluating". Thereby, the reliability of automatic driving is ensured.

[0046] The recognition unit 130 recognizes the position, and states such as speed and acceleration of an object surrounding the host vehicle M based on information input via the object recognition device 16 from the camera 10, the radar device 12, and the LIDAR 14. The position of the object is recognized, for example, as a position on the absolute coordinates with the representative point (such as the center of gravity, the center of the drive shaft, etc.) of the host vehicle M as the origin, and is used for control. The position of the object may be represented by a representative point such as the center of gravity or a corner of the object, or may be represented by a region. The "state" of the object may also include the acceleration, jerk, or "behavior state" of the object (for example, whether a lane change is being performed or about to be performed).

[0047] The recognition unit 130 recognizes, for example, the lane (travel lane) in which the host vehicle M is traveling. For example, the recognition unit 130 compares the pattern of the road dividing lines obtained from the second map information 62 (for example, the arrangement of solid lines and dotted lines) with the pattern of the road dividing lines around the host vehicle M recognized from the image captured by the camera 10, thereby recognizing the travel lane. The recognition unit 130 is not limited to recognizing road dividing lines, and may also recognize the travel lane by recognizing the road dividing lines, the travel road boundaries (road boundaries) including the road shoulder, the curb, the median strip, the guardrail, etc. In this recognition, the position of the host vehicle M obtained from the navigation device 50 and the processing result processed by the INS may also be incorporated. The recognition unit 130 recognizes a temporary stop line, an obstacle, a red light, a toll gate, and other road phenomena.

[0048] When recognizing the travel lane, the recognition unit 130 recognizes the position and attitude of the host vehicle M relative to the travel lane. For example, the recognition unit 130 may also recognize the deviation of the reference point of the host vehicle M from the center of the lane and the angle formed by the traveling direction of the host vehicle M with respect to the line connecting the centers of the lanes as the relative position and attitude of the host vehicle M relative to the travel lane. Alternatively, the recognition unit 130 may recognize the position of the reference point of the host vehicle M relative to any side end (road dividing line or road boundary) of the travel lane as the relative position of the host vehicle M relative to the travel lane.

[0049] The action plan generation unit 140 generates a target trajectory for the host vehicle M to travel automatically (independently of the driver's operation) in a manner that it travels on the recommended lane determined by the recommended lane determination unit 61 in principle and can respond to the surrounding conditions of the host vehicle M. The target trajectory includes, for example, a speed element. For example, the target trajectory is represented as a trajectory formed by arranging in sequence the points (trajectory points) that the host vehicle M should reach. The trajectory points are the points that the host vehicle M should reach at regular driving distances (for example, on the order of several [m]) along the driving distance, and in contrast, the target speed and target acceleration at regular sampling times (for example, on the order of zero point several [sec]) are generated as part of the target trajectory. The trajectory points may also be the positions that the host vehicle M should reach at regular sampling times. In this case, the information on the target speed and target acceleration is represented by the interval of the trajectory points. The action plan generation unit 140 is an example of a "generation unit".

[0050] When generating the target trajectory, the action plan generation unit 140 can set an event for autonomous driving. In the events of autonomous driving, there are a constant speed driving event, a low-speed following driving event, a lane change event, a branch event, a merging event, a takeover event, etc. The action plan generation unit 140 generates a target trajectory corresponding to the activated event.

[0051] The mode determination unit 150 determines the driving mode of the host vehicle M as any one of a plurality of driving modes with different tasks assigned to the driver. The mode determination unit 150 includes, for example, a driver state determination unit 152, a mode change processing unit 154, and a steering angular velocity determination unit 156. Their individual functions will be described later.

[0052] Figure 3 It is a diagram showing an example of the correspondence relationship between the driving mode, the control state of the host vehicle M, and the task. In the driving mode of the host vehicle M, for example, there are 5 modes from mode A to mode E. Regarding the control state, that is, the degree of automation of the driving control of the host vehicle M, mode A is the highest, and then it becomes lower in the order of mode B, mode C, and mode D, and mode E is the lowest. On the contrary, regarding the task assigned to the driver, mode A is the lightest, and then it becomes heavier in the order of mode B, mode C, and mode D, and mode E is the heaviest. In mode D or E, since it becomes a control state that is not autonomous driving, the autonomous driving control device 100 has the responsibility to end the control related to autonomous driving and transfer the control to driving support or manual driving. Hereinafter, the content of each driving mode will be exemplified.

[0053] In mode A, it is in an autonomous driving state, and neither the forward monitoring nor the grasping of the steering wheel 82 (steering grasping in the figure) is assigned to the driver. However, even in mode A, it is required that the driver be in a physical posture that can quickly switch to manual driving according to the requirements from the system centered on the autonomous driving control device 100. The autonomous driving here means that the steering and acceleration / deceleration are controlled without relying on the driver's operation. The front refers to the space in the traveling direction of the own vehicle M visually recognized through the front windshield. Mode A is, for example, a driving mode that can be executed when the following conditions are met, and is sometimes called TJP (Traffic Jam Pilot). The conditions are that on a motor vehicle-only road such as a highway, the own vehicle M is traveling at a speed equal to or lower than the upper speed limit (for example, about 50 [km / h]) and there is a preceding vehicle to follow or other conditions. When these conditions are not met, the mode determination unit 150 changes the driving mode of the own vehicle M to mode B.

[0054] In mode B, it is in a driving support state, and the task of monitoring the front of the own vehicle M (hereinafter referred to as forward monitoring) is assigned to the driver, but the task of grasping the steering wheel 82 is not assigned. In mode C, it is in a driving support state, and the tasks of forward monitoring and grasping the steering wheel 82 are assigned to the driver. Mode D is a driving mode that requires a certain degree of driving operation by the driver for at least one of the steering and acceleration / deceleration of the own vehicle M. For example, in mode D, driving supports such as ACC (Adaptive Cruise Control) and LKAS (Lane Keeping Assist System) are performed. In mode E, it is in a manual driving state where the steering and acceleration / deceleration both require driving operations by the driver. Of course, in both mode D and mode E, the task of monitoring the front of the own vehicle M is assigned to the driver.

[0055] The autonomous driving control device 100 (and the driving support device (not shown)) performs an automatic lane change corresponding to the driving mode. In the automatic lane change, there are an automatic lane change (1) under the system requirement and an automatic lane change (2) under the driver's requirement. In the automatic lane change (1), there are an overtaking automatic lane change performed when the speed of the preceding vehicle is smaller than a certain benchmark compared to the speed of the own vehicle, and an automatic lane change for traveling toward the destination (the automatic lane change caused by the recommended lane being changed). The automatic lane change (2) is to change the lane of the own vehicle M in the operation direction when the driver operates the direction indicator under the condition that the conditions regarding the vehicle speed, the positional relationship with surrounding vehicles, etc. are met.

[0056] In mode A, the autonomous driving control device 100 does not perform either of the automatic lane changes (1) and (2). In modes B and C, the autonomous driving control device 100 performs both of the automatic lane changes (1) and (2). A driving support device (not shown) does not perform the automatic lane change (1) but performs the automatic lane change (2) in mode D. In mode E, neither of the automatic lane changes (1) and (2) is performed.

[0057] When the driver does not perform the tasks related to the determined driving mode (hereinafter referred to as the current driving mode), the mode determination unit 150 changes the driving mode of the own vehicle M to a driving mode with a higher task severity.

[0058] For example, in mode A, when the driver is in a physical posture where they cannot switch to manual driving according to the system's request (for example, continuously looking around outside the permitted area, detecting signs of difficult driving), the mode determination unit 150 performs the following control: uses the HMI 30 to urge the driver to switch to manual driving, and if the driver does not respond, makes the own vehicle M approach the road shoulder and gradually stop, and stops the autonomous driving. After stopping the autonomous driving, the own vehicle M enters the state of mode D or E, and the own vehicle M can be started by the driver's manual operation. Hereinafter, the same applies to "stopping the autonomous driving". In mode B, when the driver does not monitor the front, the mode determination unit 150 performs the following control: uses the HMI 30 to urge the driver to monitor the front, and if the driver does not respond, makes the own vehicle M approach the road shoulder and gradually stop, and stops the autonomous driving. In mode C, when the driver does not monitor the front or does not hold the steering wheel 82, the mode determination unit 150 performs the following control: uses the HMI 30 to urge the driver to monitor the front and / or hold the steering wheel 82, and if the driver does not respond, makes the own vehicle M approach the road shoulder and gradually stop, and stops the autonomous driving.

[0059] The driver state determination unit 152 monitors the driver's state for the above-mentioned mode change and determines whether the driver's state is a state corresponding to the task. For example, the driver state determination unit 152 analyzes the image captured by the driver monitoring camera 70 to perform posture estimation processing and determines whether the driver is in a physical posture where they cannot switch to manual driving according to the system's request. The driver state determination unit 152 analyzes the image captured by the driver monitoring camera 70 to perform line-of-sight estimation processing and determines whether the driver is monitoring the front.

[0060] The mode change processing unit 154 performs various processes for mode change. For example, the mode change processing unit 154 instructs the action plan generation unit 140 to generate a target trajectory for stopping at the road shoulder, gives an operation instruction to a driving support device (not shown), and controls the HMI 30 to urge the driver to take action.

[0061] The function of the steering angular velocity determination unit 156 will be described later.

[0062] The second control unit 160 controls the driving force output device 200, the braking device 210, and the steering device 220 so that the vehicle M passes through the target trajectory generated by the action plan generation unit 140 at a predetermined time.

[0063] Return Figure 2 , for example, the second control unit 160 includes an acquisition unit 162, a speed control unit 164, and a steering control unit 166. The acquisition unit 162 acquires information on the target trajectory (trajectory points) generated by the action plan generation unit 140 and stores the information in a memory (not shown). The speed control unit 164 controls the driving force output device 200 or the braking device 210 based on the speed element attached to the target trajectory stored in the memory. The steering control unit 166 controls the steering device 220 according to the bending condition of the target trajectory stored in the memory. The processing of the speed control unit 164 and the steering control unit 166 is realized, for example, by a combination of feedforward control and feedback control. As an example, the steering control unit 166 combines feedforward control corresponding to the curvature of the road ahead of the vehicle M and feedback control based on the deviation from the target trajectory and executes it. The steering control unit 166 also calculates the target steering angle θ based on various element information such as the bending condition of the target trajectory stored in the memory, the speed element attached to the target trajectory, the wheelbase of the vehicle M, and the suspension characteristics (using functions, algorithms, etc. obtained from them), and sends the target steering angle θ to the mode determination unit 150.

[0064] The driving force output device 200 outputs the driving force (torque) for the vehicle M to travel to the drive wheels. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, and a transmission, and an ECU (Electronic Control Unit) that controls them. The ECU controls the above structure according to the information input from the second control unit 160 or the information input from the driving operation member 80.

[0065] The braking device 210 includes, for example, a brake caliper, a hydraulic cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure in the hydraulic cylinder, and a brake ECU. The brake ECU controls the electric motor according to the information input from the second control unit 160 or the information input from the driving operation member 80, so that a braking torque corresponding to the braking operation is output to each wheel. The braking device 210 may include a mechanism that transmits the hydraulic pressure generated by the operation of the brake pedal included in the driving operation member 80 to the hydraulic cylinder via the master hydraulic cylinder as a backup. The braking device 210 is not limited to the structure described above, and may also be an electronically controlled hydraulic braking device that controls an actuator according to the information input from the second control unit 160 to transmit the hydraulic pressure of the master hydraulic cylinder to the hydraulic cylinder.

[0066] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor, for example, applies a force to a rack-pinion mechanism to change the orientation of the steering wheels. The steering ECU drives the electric motor according to the information input from the second control unit 160 or the information input from the driving operation member 80 to change the orientation of the steering wheels.

[0067] [Control Corresponding to Steering Speed]

[0068] Hereinafter, with reference to Figure 4 and Figure 5 the content of the control related to the end of Mode A or Mode B corresponding to the steering speed executed by the mode determination unit 150 will be described.

[0069] The steering angular velocity determination unit 156 of the mode determination unit 150 obtains the target steering angle θ for following the target trajectory of the host vehicle M from the steering control unit 166, and determines whether the change speed dθ / dt1 of the target steering angle θ in the first time dt1 is equal to or greater than the first threshold, and determines whether the change speed dθ / dt2 of the target steering angle θ in the second time dt2 is equal to or greater than the second threshold. In the present embodiment, the first time dt1 is a time longer than the second time dt2. For example, the first time dt1 is set to 1 second, and the second time dt2 is set to 0.5 second. Moreover, the change speed obtained at this time is the average speed of the change of the target steering angle θ measured in the first time dt1 or the second time dt2. Generally, the change speed dθ / dt1 in the first time dt1 tends to be smaller than the change speed dθ / dt2 in the second time dr2. Therefore, the steering angular velocity determination unit 156 sets the first threshold to a value smaller than the second threshold. When the driving mode of the host vehicle M has been determined to be the driving mode of mode A or mode B, the mode change processing unit 154 changes the driving mode to mode C, mode D, or mode E when the steering angular velocity determination unit 156 determines that the change speed dθ / dt1 of the target steering angle θ in the first time dt1 is equal to or greater than the first threshold and when it is determined that the change speed dθ / dt2 of the target steering angle θ in the second time dr2 is equal to or greater than the second threshold. In the present embodiment, the mode change processing unit 154 changes the mode when the "or" condition of the determination related to the first threshold and the determination related to the second threshold is satisfied, but may also change the mode when the "and" condition is satisfied. Mode A or mode B is an example of the "second driving mode", and mode C, mode D, or mode E is an example of the "first driving mode".

[0070] Figure 4 FIG. is a diagram showing the relationship between the vehicle speed V at the time of increasing steering and the thresholds Th1 and Th2 for the steering speed dθ / dt. Here, the steering speed dθ / dt is a general term for the change speed dθ / dt1 and the change speed dθ / dt2. "When increasing steering" means a state in which the steering speed dθ / dt takes a positive value. The vehicle speed V is generated by the action plan generation unit 140 and sent to the mode determination unit 150. In Figure 4 it, the solid line represents the threshold Th1 (an example of the "first threshold") related to the change speed dθ / dt1 of the target steering angle θ in the first time dt1, and the dashed line represents the threshold Th2 (an example of the "second threshold") related to the change speed dθ / dt2 of the target steering angle θ in the second time dt2.

[0071] As Figure 4As shown, when the vehicle speed V is in the range from zero to the reference vehicle speed V1, the steering angular velocity determination unit 156 sets the threshold Th1 to the specified value F1. At this time, the specified value F1 is the maximum value that the threshold Th1 can take. Similarly, when the vehicle speed V is in the range from zero to the reference vehicle speed V1, the steering angular velocity determination unit 156 sets the threshold Th2 to the specified value F2. At this time, the specified value F2 is the maximum value that the threshold Th2 can take. This is because, assuming that in the case of a low-speed state where the vehicle speed V is above zero and below the reference vehicle speed V1, even if steering is performed at a large steering speed dθ / dt, the risk to the user is low and no steering abnormality occurs. In other words, it is assumed that the higher the vehicle speed V generated by the action plan generation unit 140, the higher the risk to the user caused by steering. Therefore, the steering angular velocity determination unit 156 sets the thresholds Th1 and Th2 for determining steering abnormality to be smaller.

[0072] Figure 5 FIG. is a diagram showing the relationship between the vehicle speed V at the time of steering withdrawal and the thresholds Th3 and Th4 for the steering speed dθ / dt. "At the time of steering withdrawal" means a state where the steering speed dθ / dt takes a negative value. In Figure 5 FIG., the solid line represents the threshold Th3 (another example of the "first threshold") related to the change speed dθ / dt1 of the target steering angle θ in the first time dt1, and the dashed line represents the threshold Th4 (another example of the "second threshold") related to the change speed dθ / dt2 of the target steering angle θ in the second time dt2. Regarding the magnitude relationship between the thresholds Th3 and Th4, and the tendency that the higher the vehicle speed V, the lower their thresholds are set, it is the same as the Figure 4 thresholds Th1 and Th2.

[0073] On the other hand, in Figure 5 FIG., when the steering direction of the own vehicle M is the steering withdrawal direction, the steering angular velocity determination unit 156 sets the threshold Th3 to be larger than the threshold Th1 (i.e., sets the first threshold relatively large) and sets the threshold Th4 to be larger than the threshold Th2 (i.e., sets the second threshold relatively large) compared to when the steering direction is the steering increase direction. This is because, assuming that when the steering direction of the own vehicle M is the steering withdrawal direction, the own vehicle M has a tendency to return to the original forward road. Therefore, even if steering is performed at a large steering speed dθ / dt, the risk to the user is low and no steering abnormality occurs. That is, the thresholds for determining steering abnormality can be flexibly set according to the magnitude of the vehicle speed V and the steering direction.

[0074] In Figure 4 and Figure 5In this case, the steering angular velocity determination unit 156 causes various thresholds to decrease in a stepped manner as the vehicle speed V increases. However, the manner of decreasing the thresholds is not limited to this, and they may decrease linearly, curvilinearly, stepwise, etc., as long as there is a tendency for the thresholds to decrease as the vehicle speed V increases, and they may decrease in any manner. Also, although the threshold Th3 is set to be larger than the threshold Th1 and the threshold Th4 is set to be larger than the threshold Th2, in the low vehicle speed region where the vehicle speed V reaches V1, the values of both may be the same. This is because it is assumed that in the low vehicle speed region, steering enhancement is as safe as steering retraction for the user and no steering abnormality occurs.

[0075] Next, with reference to Figure 6 , the change process of the driving mode executed by the mode determination unit 150 will be described. Figure 6 FIG. is a flowchart showing an example of the change process of the driving mode executed by the mode determination unit 150. The process of this flowchart starts when the vehicle M starts driving in the second driving mode.

[0076] First, the mode determination unit 150 obtains the target steering angle θ from the steering control unit 166 across the first time dt1, and calculates the change speed, i.e., the first steering angular velocity dθ / dt1, in this first time dt1 (S1). Next, the mode determination unit 150 obtains the target steering angle θ from the steering control unit 166 across the second time dt2, and calculates the change speed, i.e., the second steering angular velocity dθ / dt2, in this second time dt2 (S2). For the sake of explanation, S1 and S2 are set as serial processes, but S1 and S2 may also be parallel processes.

[0077] Next, the mode determination unit 150 determines whether the steering direction is the steering enhancement direction based on the calculated first steering angular velocity dθ / dt1 or second steering angular velocity dθ / dt2 (S3). Specifically, when the calculated first steering angular velocity dθ / dt1 or second steering angular velocity dθ / dt2 is positive, the mode determination unit 150 determines that the steering direction is the steering enhancement direction. Here, it is also assumed that there may be a case where the signs of dθ / dt1 and dθ / dt2 are different. In this case, the steering enhancement cannot be defined, but such a case is not originally a case of sharply steering at high speed, so the processes of S4 to S8 may be skipped and the process may return to S1.

[0078] When the mode determination unit 150 determines that the steering direction is the steering acceleration direction, it determines whether the first steering angular velocity dθ / dt1 is equal to or greater than the threshold value Th1 (S4). When the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is equal to or greater than the threshold value Th1, it changes the driving mode from the second driving mode to the first driving mode and ends the process (S6). On the other hand, when the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is not equal to or greater than the threshold value Th1, it determines whether the second steering angular velocity dθ / dt2 is equal to or greater than the threshold value Th2 (S5). When the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is equal to or greater than the threshold value Th2, it changes the driving mode from the second driving mode to the first driving mode (S8). On the other hand, when the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is not equal to or greater than the threshold value Th2, it returns the process to S1 again.

[0079] When the mode determination unit 150 determines that the steering direction is not the steering acceleration direction, it determines whether the first steering angular velocity dθ / dt1 is equal to or greater than the threshold value Th3 (S7). When the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is equal to or greater than the threshold value Th3, it changes the driving mode from the second driving mode to the first driving mode and ends the process (S6). On the other hand, when the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is not equal to or greater than the threshold value Th3, it determines whether the second steering angular velocity dθ / dt2 is equal to or greater than the threshold value Th4 (S8). When the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is equal to or greater than the threshold value Th4, it changes the driving mode from the second driving mode to the first driving mode (S8). On the other hand, when the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is not equal to or greater than the threshold value Th4, it returns the process to S1 again.

[0080] Through the above processing, the mode determination unit 150 compares the first steering angular velocity dθ / dt1 with the first threshold value and compares the second steering angular velocity dθ / dt2 with the second threshold value. Thus, when the first steering angular velocity dθ / dt1 is equal to or greater than the first threshold value or the second steering angular velocity dθ / dt2 is equal to or greater than the second threshold value, it determines that the steering is abnormal and changes the driving mode. Thereby, it is possible to reliably determine the steering abnormality without omission.

[0081] <Second Embodiment>

[0082] Next, with reference to Figure 7 , another example of the driving mode change process executed by the mode determination unit 150 will be described. Figure 7 is a flowchart showing another example of the driving mode change process executed by the mode determination unit 150. InFigure 7 in which, the processing from S1 to S3 is the same as Figure 6 the same, so the description is omitted.

[0083] When the mode determination unit 150 determines in S3 that the steering direction is the steering promotion direction, it determines whether the first steering angular velocity dθ / dt1 is equal to or greater than the threshold Th1 (S4). When the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is equal to or greater than the threshold Th1, it determines whether the second steering angular velocity dθ / dt2 is equal to or greater than the threshold Th2 (S5). On the other hand, when the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is not equal to or greater than the threshold Th1, it returns the process to S1 again. When the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is equal to or greater than the threshold Th2, it changes the driving mode from the second driving mode to the first driving mode (S6). On the other hand, when the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is not equal to or greater than the threshold Th2, it returns the process to S1 again.

[0084] When the mode determination unit 150 determines in S3 that the steering direction is not the steering promotion direction, it determines whether the first steering angular velocity dθ / dt1 is equal to or greater than the threshold Th3 (S7). When the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is equal to or greater than the threshold Th3, it determines whether the second steering angular velocity dθ / dt2 is equal to or greater than the threshold Th4 (S8). On the other hand, when the mode determination unit 150 determines that the first steering angular velocity dθ / dt1 is not equal to or greater than the threshold Th3, it returns the process to S1 again. When the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is equal to or greater than the threshold Th4, it changes the driving mode from the second driving mode to the first driving mode (S6). On the other hand, when the mode determination unit 150 determines that the second steering angular velocity dθ / dt2 is not equal to or greater than the threshold Th4, it returns the process to S1 again.

[0085] According to the second embodiment described above, the mode determination unit 150 is different from the first embodiment. When the first steering angular velocity dθ / dt1 is equal to or greater than the first threshold and the second steering angular velocity dθ / dt2 is equal to or greater than the second threshold, it determines that the steering is abnormal and changes the driving mode. Thus, it is possible to prevent misjudgment by the mode determination unit 150.

[0086] The above-described embodiments can be expressed as follows.

[0087] The vehicle control device is configured to include a storage device storing a program and a hardware processor, and performs the following processing by executing the program stored in the storage device by the hardware processor:

[0088] Generate a target trajectory for the vehicle;

[0089] Determine whether the change speed of the target steering angle for following the target trajectory is above a first threshold at a first time, and determine whether the change speed of the target steering angle is above a second threshold at a second time;

[0090] Determine any one of a plurality of driving modes including a first driving mode and a second driving mode as the driving mode of the vehicle, and the task assigned to the driver in the second driving mode is lighter than that in the first driving mode;

[0091] When the driving mode of the vehicle has been determined to be the second driving mode, when it is determined that the change speed of the target steering angle is above the first threshold at the first time and when it is determined that the change speed of the target steering angle is above the second threshold at the second time, change the driving mode of the vehicle to the first driving mode both times,

[0092] The first time is a time longer than the second time,

[0093] The first threshold is a value smaller than the second threshold.

[0094] The specific embodiments of the present invention have been described above using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and substitutions can be made without departing from the gist of the present invention.

Claims

1. A vehicle control device, wherein, The vehicle control device includes: a generation unit that generates a target trajectory of the vehicle; a determination unit that determines whether a change speed of a target steering angle for following the target trajectory in a first time is equal to or greater than a first threshold value, and determines whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold value; and a mode determination unit that determines the driving mode of the vehicle as either one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode, when the mode determination unit has determined the driving mode of the vehicle as the second driving mode, at both times when the determination unit determines that the change speed of the target steering angle in the first time is equal to or greater than the first threshold value and when it determines that the change speed of the target steering angle in the second time is equal to or greater than the second threshold value, the driving mode of the vehicle is changed to the first driving mode, the first time is a time longer than the second time, the first threshold value is a value smaller than the second threshold value.

2. A vehicle control device, wherein, The vehicle control device includes: an acquisition unit that acquires a target steering angle for following a target trajectory of the vehicle; a determination unit that determines whether a change speed of the target steering angle in a first time is equal to or greater than a first threshold value, and determines whether a change speed of the target steering angle in a second time is equal to or greater than a second threshold value; and a mode determination unit that determines the driving mode of the vehicle as either one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode, when the mode determination unit has determined the driving mode of the vehicle as the second driving mode, when the determination unit determines that the change speed of the target steering angle in the first time is equal to or greater than the first threshold value and the change speed of the target steering angle in the second time is equal to or greater than the second threshold value, the driving mode of the vehicle is changed to the first driving mode, the first time is a time longer than the second time, the first threshold value is a value smaller than the second threshold value.

3. The vehicle control device according to claim 1 or 2, wherein, The higher the vehicle speed of the vehicle, the smaller the determination unit sets the first threshold value or the second threshold value.

4. The vehicle control device according to claim 1 or 2, wherein, When the vehicle speed of the vehicle is in the range from zero to a reference vehicle speed, the determination unit sets the first threshold value or the second threshold value to a specified value.

5. The vehicle control device according to claim 4, wherein, The second driving mode includes a driving mode in which neither the front monitoring of the vehicle nor the holding of the steering wheel of the vehicle is assigned to the driver, and an upper limit vehicle speed for the vehicle is set, the reference vehicle speed is the upper limit vehicle speed.

6. The vehicle control device according to claim 1 or 2, wherein, When the steering direction of the vehicle is a steering return direction, the determination unit sets the first threshold value or the second threshold value to be larger than the corresponding first threshold value or second threshold value when the steering direction is a steering increase direction.

7. A vehicle control method, wherein, The vehicle control method causes a vehicle control device to perform the following processing: acquire a target steering angle for following a target trajectory of the vehicle; Determine whether the change speed of the target steering angle in the first time is above a first threshold, and determine whether the change speed of the target steering angle in the second time is above a second threshold; Determine the driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode; When the driving mode of the vehicle has been determined to be the second driving mode, when it is determined that the change speed of the target steering angle in the first time is above the first threshold and when it is determined that the change speed of the target steering angle in the second time is above the second threshold, change the driving mode of the vehicle to the first driving mode both times; The first time is a time longer than the second time; The first threshold is a value smaller than the second threshold.

8. A vehicle control method, wherein, The vehicle control method causes a vehicle control device to perform the following processing: Obtain a target steering angle for following a target track of the vehicle; Determine whether the change speed of the target steering angle in the first time is above a first threshold, and determine whether the change speed of the target steering angle in the second time is above a second threshold; Determine the driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode; When the driving mode of the vehicle has been determined to be the second driving mode, when it is determined that the change speed of the target steering angle in the first time is above the first threshold and the change speed of the target steering angle in the second time is above the second threshold, change the driving mode of the vehicle to the first driving mode; The first time is a time longer than the second time; The first threshold is a value smaller than the second threshold.

9. A storage medium stores a program, wherein, The program causes a processor of a vehicle control device to perform the following processing: Obtain a target steering angle for following a target track of the vehicle; Determine whether the change speed of the target steering angle in the first time is above a first threshold, and determine whether the change speed of the target steering angle in the second time is above a second threshold; Determine the driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode; When the driving mode of the vehicle has been determined to be the second driving mode, when it is determined that the change speed of the target steering angle in the first time is above the first threshold and when it is determined that the change speed of the target steering angle in the second time is above the second threshold, change the driving mode of the vehicle to the first driving mode both times; The first time is a time longer than the second time; The first threshold is a value smaller than the second threshold.

10. A storage medium stores a program, wherein, The program causes a processor of a vehicle control device to perform the following processing: Obtain a target steering angle for following a target track of the vehicle; Determine whether the change speed of the target steering angle in the first time is above a first threshold, and determine whether the change speed of the target steering angle in the second time is above a second threshold; Determine the driving mode of the vehicle to be any one of a plurality of driving modes including a first driving mode and a second driving mode, and the tasks assigned to the driver in the second driving mode are less intensive than those in the first driving mode; When the driving mode of the vehicle has been determined to be the second driving mode, if it is determined that the change speed of the target steering angle in the first time is above the first threshold and the change speed of the target steering angle in the second time is above the second threshold, change the driving mode of the vehicle to the first driving mode, The first time is a time longer than the second time, The first threshold is a value smaller than the second threshold.

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