Vehicle control device, vehicle control method, and storage medium

Abstract

The invention provides a vehicle control apparatus, a vehicle control method, and a storage medium. A vehicle control device is provided with: a recognition unit that recognizes a dividing line of a road on which a host vehicle travels; a prediction unit that calculates a predicted route of the host vehicle on the basis of the traveling state of the host vehicle; an intersection determination unit that determines whether or not to intersect the predicted path for each predetermined section of the division line; and a determination unit that, when it is determined that the predicted route intersects a division line of the predetermined section, calculates a surplus time until the vehicle reaches the intersection of the predicted route and the division line, and, when the surplus time is equal to or less than a threshold value, determines that the vehicle reaches the intersection of the predicted route and the division line. It is determined that the vehicle is highly likely to leave the dividing line.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2024-051036, filed on March 27, 2024, the contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to a vehicle control device, a vehicle control method and a storage medium. Background Art

[0003] In recent years, efforts have been underway to provide access to sustainable transportation systems that are also considerate of vulnerable road users. Toward this goal, research and development related to preventive safety technologies is being pursued to further improve traffic safety and convenience. For example, technology has traditionally been available for detecting when a moving vehicle has left its lane (e.g., see Japanese Patent No. 4534754). Summary of the Invention

[0004] Conventional technology determines departure based on the lateral deviation of the vehicle's position from the lane center. It then uses the yaw angle to predict the departure direction or the direction to avoid it. The greater the departure tendency, the greater the degree of lane keeping control. In other words, conventional technology, which uses lateral deviation to determine departure, can cause delays in control and notification when the vehicle is traveling on a curve.

[0005] The present invention provides a vehicle control device, a vehicle control method, and a storage medium that can appropriately perform a vehicle departure determination when the vehicle is traveling on a curve. Furthermore, the present invention contributes to the development of a sustainable transportation system.

[0006] The vehicle control device of the present invention adopts the following structure.

[0007] (1): A vehicle control device according to one embodiment of the present invention comprises: an identification unit for identifying a dividing line of a road on which the vehicle is traveling; a prediction unit for calculating a predicted path of the vehicle based on the driving state of the vehicle; an intersection determination unit for determining whether the vehicle intersects with the predicted path in each specified interval of the dividing line; and a determination unit for calculating a surplus time until the vehicle reaches an intersection of the predicted path and the dividing line when it is determined that the predicted path intersects with the dividing line of the specified interval, and determining that there is a high possibility that the vehicle will deviate from the dividing line when the surplus time is below a threshold.

[0008] (2): In the above-mentioned aspect (1), when the host vehicle is traveling with a turning motion, the intersection determination unit calculates the predicted path using a turning curve obtained based on the current traveling state of the host vehicle.

[0009] (3): In the above-mentioned aspect (1), when the host vehicle is traveling with a turning motion, the determination unit calculates the margin time using a turning curve obtained based on a current traveling state of the host vehicle.

[0010] (4): In the above-mentioned configuration (2) or (3), the center of the turning curve is set to the side of the vehicle.

[0011] (5): In the above-mentioned scheme (4), the center is set in a direction perpendicular to the front direction of the vehicle from the end or the ground contact point of the vehicle that is close to the predetermined section.

[0012] (6): In another embodiment of the vehicle control method of the present invention, the control device of the vehicle performs the following processing: identifying the dividing line of the road on which the vehicle is traveling; calculating the predicted path of the vehicle based on the driving state of the vehicle; determining whether the predicted path intersects with the predicted path according to each specified interval of the dividing line; and when it is determined that the predicted path intersects with the dividing line of the specified interval, calculating the surplus time until the vehicle reaches the intersection of the predicted path and the dividing line, and when the surplus time is below a threshold, determining that there is a high possibility that the vehicle will deviate from the dividing line.

[0013] (7): The storage medium of another embodiment of the present invention is a computer-readable non-temporary storage medium, wherein the storage medium stores a program for causing the control device of the vehicle to perform the following processing: identifying the dividing line of the road on which the vehicle is traveling; calculating the predicted path of the vehicle based on the driving state of the vehicle; determining whether the predicted path intersects with the predicted path according to each specified interval of the dividing line; and when it is determined that the predicted path intersects with the dividing line of the specified interval, calculating the surplus time until the vehicle reaches the intersection of the predicted path and the dividing line, and when the surplus time is below a threshold, determining that there is a high possibility that the vehicle will deviate from the dividing line.

[0014] According to the above aspects (1) to (7), it is possible to provide a vehicle control device, a vehicle control method, and a storage medium capable of appropriately performing a departure determination when the vehicle is traveling on a curve.

[0015] More specifically, according to the schemes (1), (6), and (7), the intersection is determined by calculating the predicted path of the host vehicle relative to the road dividing line. This makes it possible to suppress delays in control and notification even when there is a possibility of deviation during curve driving. Furthermore, by determining the presence of an intersection (intersection determination) for each predetermined section of the road dividing line, the processing load of the deviation determination can be reduced, thereby reducing the possibility of delays in the determination.

[0016] Furthermore, according to the solution (2), when the vehicle is traveling with a turning motion, intersection determination is performed using a turning curve (curvature) calculated based on the current driving state. This allows for appropriate determination of the likelihood of departure even while traveling on a curve. Furthermore, by performing intersection determination based on the turning curve, the processing load can be reduced, thereby reducing the likelihood of delays in determination.

[0017] Furthermore, according to the embodiment (3), when the vehicle is traveling with a turning motion, the possibility of departure can be appropriately determined even when traveling on a curve by using the turning curve (curvature) calculated based on the current driving state. Furthermore, by using the turning curve to determine the possibility of departure, the processing load can be reduced, and the possibility of delay in determination can be reduced.

[0018] Furthermore, in conventional technology, when calculating the turning center (rotation center), the influence of lateral velocity errors increases when the radius of curvature increases, and it may be impossible to accurately calculate the distance from the lane departure. According to the scheme (4), by setting the turning center to the side of the vehicle, the accuracy of intersection determination and departure determination during turning can be improved.

[0019] Furthermore, according to the aspect (5), the departure determination is performed on a portion of the vehicle that is highly likely to depart from the lane, thereby improving the accuracy of the departure determination. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0023] Figure 4 This is a flowchart showing an example of the flow of basic processing in departure determination.

[0024] Figure 5 This is a schematic diagram for explaining the outline of the separation determination.

[0025] Figure 6 This is a diagram explaining a method of calculating the turning speed and turning center of the host vehicle when traveling along a curve in departure determination.

[0026] Figure 7 This is a first diagram illustrating a method of calculating a departure path length for a host vehicle traveling a curve in departure determination.

[0027] Figure 8 This is a second diagram illustrating a method of calculating the length of a departure path for the host vehicle when traveling along a curve in the departure determination.

[0028] Figure 9 The third diagram is a diagram illustrating a method for calculating the length of a departure path for the host vehicle when traveling along a curve in the departure determination. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of a vehicle control device, a vehicle control method, and a storage medium according to the present invention will be described with reference to the accompanying drawings.

[0030] [Overall structure]

[0031] Figure 1 This is a structural diagram of a vehicle system 1 utilizing a vehicle control device according to an embodiment. The vehicle equipped with vehicle system 1 is, for example, a two-wheeled, three-wheeled, or four-wheeled vehicle, and its driving 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 power generated by a generator coupled to the internal combustion engine, or power discharged from a secondary battery or fuel cell.

[0032] 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, a vehicle sensor 40, a navigation device 50, an MPU (Map Positioning Unit) 60, a driver monitoring camera 70, a driving operating element 80, an automatic 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 through multiple communication lines such as CAN (Controller Area Network) communication lines, serial communication lines, wireless communication networks, etc. It should be noted that Figure 1 The structure shown is merely an example, and part of the structure may be omitted or other structures may be added.

[0033] Camera 10 is, for example, a digital camera utilizing a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). Camera 10 is mounted at any location on a vehicle equipped with vehicle system 1 (hereinafter referred to as the vehicle itself). For forward imaging, camera 10 is mounted above the windshield, behind the rearview mirror, or elsewhere in the vehicle. Camera 10, for example, periodically and repeatedly captures the surroundings of the vehicle itself. Camera 10 may also be a stereo camera.

[0034] Radar device 12 radiates radio waves, such as millimeter waves, around the vehicle and detects the radio waves (reflected waves) reflected by objects to detect at least the object's position (range and direction). Radar device 12 can be installed anywhere on the vehicle. Radar device 12 can also detect the position and velocity of objects using FM-CW (Frequency Modulated Continuous Wave) technology.

[0035] LIDAR 14 irradiates light (or electromagnetic waves with a wavelength close to that of light) around the vehicle and measures the scattered light. LIDAR 14 detects the distance to an object based on the time between light emission and light reception. The irradiated light is, for example, a pulsed laser. LIDAR 14 can be mounted anywhere on the vehicle.

[0036] The object recognition device 16 performs sensor fusion processing on the detection results from some or all of the camera 10, radar device 12, and LIDAR 14 to identify the position, type, speed, etc. of the object. The object recognition device 16 outputs the recognition results to the automatic driving control device 100. The object recognition device 16 may also output the detection results from the camera 10, radar device 12, and LIDAR 14 directly to the automatic driving control device 100. The object recognition device 16 may also be omitted from the vehicle system 1.

[0037] The communication device 20 communicates with other vehicles around the vehicle using, for example, a cellular network, Wi-Fi network, Bluetooth (registered trademark), DSRC (Dedicated Short Range Communication), or communicates with various server devices via a wireless base station.

[0038] The HMI 30 presents various information to the occupants of the vehicle and receives input operations from the occupants. The HMI 30 includes various display devices, speakers, buzzers, touch panels, switches, buttons, and the like.

[0039] The vehicle sensor 40 includes a vehicle speed sensor that detects the speed of the vehicle, an acceleration sensor that detects acceleration, a yaw rate sensor that detects angular velocity about a vertical axis, an azimuth sensor that detects the orientation of the vehicle, and the like.

[0040] 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 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 vehicle based on signals received from GNSS satellites. The position of the vehicle 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. A part or all of the navigation HMI 52 can also be shared with the above-mentioned HMI 30. The route determination unit 53, for example, refers to the first map information 54 to determine a route (hereinafter referred to as a route on the map) from the position of the vehicle determined by the GNSS receiver 51 (or an arbitrary position input) to the destination input by the passenger using the navigation HMI 52. The first map information 54 is information that represents the shape of the road by, for example, lines representing the road and nodes connected by the lines. The first map information 54 may also include road curvature, POI (Point of Interest) information, and the like. The route on the map is output to the MPU 60. The navigation device 50 may also provide route guidance using the navigation HMI 52 based on the route on the map. The navigation device 50 may also be implemented as a function of a terminal device such as a smartphone or tablet computer held by the passenger. The navigation device 50 may also transmit the current location and destination to a navigation server via the communication device 20 and obtain a route equivalent to the route on the map from the navigation server.

[0041] The MPU 60, for example, includes a recommended lane determination unit 61, which stores second map information 62 in a storage device such as a HDD or flash memory. The recommended lane determination unit 61 divides the route on the map provided by the navigation device 50 into multiple segments (e.g., every 100 meters in the vehicle's direction of travel), references the second map information 62, and determines a recommended lane for each segment. The recommended lane determination unit 61 determines the lane from the left to which the vehicle should travel. If the route on the map branches, the recommended lane determination unit 61 determines a recommended lane so that the vehicle can travel on a reasonable route to the branch destination.

[0042] 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 about lane centers or lane boundaries. Furthermore, the second map information 62 may include road information, traffic restriction information, address information (address, postal code), facility information, phone number information, and information about prohibited sections where Mode A or Mode B, described later, is prohibited. The second map information 62 can be updated at any time by communicating with other devices via the communication device 20.

[0043] The driver monitoring camera 70 is, for example, a digital camera utilizing a solid-state imaging element such as a CCD or CMOS. The driver monitoring camera 70 is mounted at any location within the vehicle in a position and orientation capable of capturing a frontal image (the orientation in which the face is captured) of the head of a passenger seated in the driver's seat of the vehicle (hereinafter referred to as the driver). For example, the driver monitoring camera 70 is mounted above a display device located in the center of the vehicle's instrument panel.

[0044] The driving operating member 80 includes, for example, not only a steering wheel 82 but also an accelerator pedal, a brake pedal, a gear lever, and other operating members. A sensor that detects the amount of operation or the presence or absence of operation is installed on the driving operating member 80, and its detection result is output to the automatic driving control device 100, or part or all of the driving force output device 200, the braking device 210, and the steering device 220. The steering wheel 82 is an example of an "operating member that receives steering operations performed by the driver." The operating member does not necessarily have to be annular, and can also be in the form of a special-shaped steering wheel, a joystick, a button, etc. A steering grip sensor 84 is installed on the steering wheel 82. The steering grip sensor 84 is implemented by an electrostatic capacitance sensor, etc., and outputs a signal that can detect whether the driver is gripping the steering wheel 82 (meaning contact with force applied) to the automatic driving control device 100.

[0045] The automatic driving control device 100 includes, for example, a first control unit 120, a second control unit 160, and a third control unit 180. The first control unit 120 and the second control unit 160 are each implemented by, for example, a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Furthermore, some or all of these components may be implemented using hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a GPU (Graphics Processing Unit), or a SOC (System On Chip), or through the coordinated implementation of software and hardware. The program may be pre-stored in a storage device (including a non-transitory storage medium) such as an HDD or flash memory of the automatic driving control device 100, or may be stored in a removable storage medium such as a DVD or CD-ROM and installed in the HDD or flash memory of the automatic driving control device 100 by attaching the storage medium (non-transitory storage medium) to a drive device. The automatic driving control device 100 is an example of a “vehicle control device”, and the portion including the action plan generating unit 140 and the second control unit 160 is an example of a “driving control unit”.

[0046] Figure 2 This 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, for example, functions based on AI (Artificial Intelligence) and functions based on a pre-provided model in parallel. For example, the function of "identifying intersections" is achieved by executing in parallel the identification of intersections based on deep learning and the like and the identification based on pre-provided conditions (the presence of signals, road signs, etc. that can perform pattern matching), and comprehensively evaluating both by adding scores. In this way, the reliability of autonomous driving can be ensured.

[0047] The recognition unit 130 recognizes the position, speed, acceleration and other states of objects located around the vehicle based on the information input from the camera 10, the radar device 12 and the LIDAR 14 via the object recognition device 16. The position of the object is, for example, recognized as a position on an absolute coordinate with a representative point (center of gravity, drive shaft center, etc.) of the vehicle as the origin, and is used in the control. The position of the object can also be represented by a representative point such as the center of gravity or a corner of the object, or by an area. The "state" of the object can include the acceleration, jerk, or "action state" of the object (for example, whether a lane change is in progress or about to be made).

[0048] In addition, the recognition unit 130, for example, recognizes the lane in which the vehicle is traveling (driving lane). For example, the recognition unit 130 recognizes the driving lane by comparing the pattern of road dividing lines obtained from the second map information 62 (for example, the arrangement of solid lines and dotted lines) with the pattern of road dividing lines around the vehicle recognized from the image captured by the camera 10. It should be noted that the recognition unit 130 is not limited to recognizing road dividing lines, but can also recognize the driving lane by recognizing the driving road boundaries (road boundaries) including road dividing lines, shoulders, curbs, central median strips, guardrails, etc. The position of the vehicle obtained from the navigation device 50 and the processing results based on the INS can also be included in this recognition. In addition, the recognition unit 130 recognizes temporary stop lines, obstacles, red lights, toll booths, and other road matters.

[0049] When identifying a lane, the recognition unit 130 identifies the position and posture of the vehicle relative to the lane. For example, the recognition unit 130 may identify the relative position and posture of the vehicle relative to the lane by using the deviation of the vehicle's reference point from the center of the lane and the angle formed by the vehicle's travel direction relative to a line connecting the lane centers. Alternatively, the recognition unit 130 may identify the relative position of the vehicle relative to the lane by using the position of the vehicle's reference point relative to either end of the lane (a road dividing line or a road boundary).

[0050] The action plan generation unit 140 generates a target trajectory for the vehicle M to automatically (independently of the driver's operation) travel in the future, so that the vehicle M, in principle, travels on the recommended lane determined by the recommended lane determination unit 61 and avoids approaching objects identified by the recognition unit 130 (excluding road dividing lines, road signs, manholes, etc. that can be crossed). For example, the recognition unit 130 sets a risk area centered on the object whose status is output, and within the risk area, the recognition unit 130 sets the risk as an indicator value indicating the degree to which the vehicle M should not approach. The action plan generation unit 140 generates a target trajectory so as to avoid passing through locations where the risk is greater than a specified value. Since the objects include moving objects, the risk distribution is not a single one in each control cycle, but is set for multiple future time points, taking into account the future position of the object predicted based on the object's speed. The target trajectory includes, for example, a speed factor. For example, the target trajectory is represented by a trajectory in which the locations (track points) that the vehicle should reach are arranged in sequence. Track points are locations along the route that the vehicle should reach at predetermined travel distances (e.g., a few meters). Unlike these, target speeds and accelerations are generated as part of the target trajectory at predetermined sampling intervals (e.g., a few tenths of a second). Alternatively, track points can be locations that the vehicle should reach at predetermined sampling intervals. In this case, target speed and acceleration information is expressed at intervals between track points.

[0051] Action plan generator 140 may also set autonomous driving events when generating a target trajectory. These events include constant speed driving, low-speed following, lane change, diverging, merging, and takeover. Action plan generator 140 generates a target trajectory corresponding to the initiated event.

[0052] The mode determination unit 150 determines the driving mode of the host vehicle to be 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 and a mode change processing unit 154. The individual functions of these will be described later.

[0053] Figure 3It is a diagram showing an example of the correspondence between the driving mode, the control state of the vehicle, and the task. Among the driving modes of the vehicle, there are five modes, for example, mode A to mode E. In the control state, that is, the degree of automation of the driving control of the vehicle, mode A is the highest, followed by mode B, mode C, and mode D in the order of automation, with mode E being the lowest. Conversely, among the tasks assigned to the driver, mode A is the lightest, followed by mode B, mode C, and mode D in the order of automation, with mode E being the heaviest. It should be noted that in modes D and E, the control state is not an automatic driving state, and therefore, as the automatic driving control device 100, its responsibility is to end the control of the automatic driving until it switches to driving assistance or manual driving. The following is an example of the contents of each driving mode.

[0054] In mode A, the vehicle is in an automatic driving state, and the driver is not assigned to forward monitoring or the control of the steering wheel 82 (steering control in the figure). However, even in mode A, the driver is required to be able to quickly switch to manual driving according to the requirements from the system centered on the automatic driving control device 100. It should be noted that the automatic driving mentioned here refers to a situation where steering and acceleration and deceleration are controlled independently of the driver's operation. The front refers to the space in which the direction of travel of the vehicle is visually confirmed through the front windshield. Mode A is a driving mode that can be executed when the following conditions are met, for example, the vehicle is traveling at a specified speed (for example, about 50 [km / h]) or less on a motor vehicle-only road such as an expressway and there is a preceding vehicle to be followed. It is sometimes called TJP (Traffic Jam Pilot). When this condition is no longer met, the mode determination unit 150 changes the driving mode of the vehicle to mode B.

[0055] In mode B, the state is set to driving support, and although the driver is assigned the task of monitoring the front of the vehicle (hereinafter referred to as front monitoring), the task of holding the steering wheel 82 is not assigned. In mode C, the state is set to driving support, and the driver is assigned the task of monitoring the front and the task of holding the steering wheel 82. Mode D is a driving mode that requires a certain degree of driving operation by the driver with respect to at least one of the steering and acceleration and deceleration of the vehicle. For example, in mode D, driving support such as ACC (Adaptive Cruise Control) and LKAS (Lane Keeping Assist System) is performed. In mode E, the state is set to manual driving, in which the steering and acceleration and deceleration both require driving operations performed by the driver. Of course, both modes D and E assign the driver the task of monitoring the front of the vehicle.

[0056] The automatic driving control device 100 (and the driving support device (not shown)) executes automatic lane changes according to the driving mode. In the automatic lane changes, there are automatic lane changes based on system requirements (1) and automatic lane changes based on driver requirements (2). In the automatic lane change (1), there are automatic lane changes for overtaking when the speed of the preceding vehicle is lower than the speed of the host vehicle by more than a reference, and automatic lane changes for traveling toward the destination (automatic lane changes caused by changing the recommended lane). In the automatic lane change (2), when the conditions related to the speed, the positional relationship with the surrounding vehicles, etc. are met, when the driver operates the direction indicator, the host vehicle changes lanes in the direction of operation.

[0057] In mode A, the automatic driving control device 100 does not execute either automatic lane change (1) or automatic lane change (2). In modes B and C, the automatic driving control device 100 executes both automatic lane change (1) and automatic lane change (2). In mode D, the driving support device (not shown) does not execute automatic lane change (1) but executes automatic lane change (2). In mode E, neither automatic lane change (1) nor automatic lane change (2) is executed.

[0058] If the driver is not performing the tasks of the determined driving mode (hereinafter referred to as the current driving mode), the mode determination unit 150 changes the driving mode of the host vehicle to a driving mode with a heavier task.

[0059] For example, in Mode A, if the driver is in a position where they are unable to switch to manual driving in response to a system request (e.g., if they are continuously looking to the side outside the permitted area or if a sign of driving difficulty is detected), the mode determination unit 150 performs the following control: using the HMI 30 to urge the driver to switch to manual driving. If the driver does not respond, the vehicle is gradually brought to a stop near the roadside, and automated driving is discontinued. After automated driving is discontinued, the vehicle enters Mode D or E, and can be started manually by the driver. The same applies to "disabling automated driving" below. In Mode B, if the driver is not monitoring the forward direction, the mode determination unit 150 performs the following control: using the HMI 30 to urge the driver to monitor the forward direction. If the driver does not respond, the vehicle is gradually brought to a stop near the roadside, and automated driving is discontinued. In Mode C, if the driver is not monitoring the forward direction or is not holding the steering wheel 82, the mode determination unit 150 performs the following control: using the HMI 30 to urge the driver to monitor the forward direction and / or hold the steering wheel 82. If the driver does not respond, the vehicle is gradually brought to a stop near the roadside, and automated driving is discontinued.

[0060] To perform the aforementioned mode change, the driver state determination unit 152 monitors the driver's state and determines whether the driver's state is appropriate for the task. For example, the driver state determination unit 152 analyzes images captured by the driver monitoring camera 70 to perform posture estimation processing to determine whether the driver is in a posture that prevents the system from requesting a change to manual driving. Furthermore, the driver state determination unit 152 analyzes images captured by the driver monitoring camera 70 to perform line of sight estimation processing to determine whether the driver is monitoring the area ahead.

[0061] 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 a roadside stop, instructs a driving support device (not shown) to operate, or controls the HMI 30 to urge the driver to take action.

[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 host vehicle passes through the target trajectory generated by the action plan generation unit 140 at a predetermined timing.

[0063] Return to Figure 2 , the second control unit 160 includes, for example, an acquisition unit 162, a speed control unit 164, and a steering control unit 166. The acquisition unit 162 acquires the information of the target track (track point) generated by the action plan generation unit 140 and stores it 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 track stored in the memory. The steering control unit 166 controls the steering device 220 according to the degree of curvature of the target track stored in the memory. The processing of the speed control unit 164 and the steering control unit 166 is implemented, for example, by a combination of feedforward control and feedback control. As an example, the steering control unit 166 performs a combination of feedforward control corresponding to the curvature of the road in front of the vehicle and feedback control based on the deviation from the target track.

[0064] The driving force output device 200 outputs driving force (torque) to the drive wheels for driving the vehicle. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, and a transmission, as well as an ECU (Electronic Control Unit) that controls these components. The ECU controls the aforementioned components based on information input from the second control unit 160 or from the driving operating element 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 information input from the second control unit 160 or information input from the driving operating element 80, and outputs a braking torque corresponding to the braking operation to each wheel. The braking device 210 may also include a mechanism that transmits the hydraulic pressure generated by operating the brake pedal included in the driving operating element 80 to the hydraulic cylinder via a master hydraulic cylinder as a backup. It should be noted that the braking device 210 is not limited to the structure described above, and may also be an electronically controlled hydraulic braking device that controls the actuator according to information input from the second control unit 160 and transmits the hydraulic pressure of the master hydraulic cylinder to the hydraulic cylinder.

[0066] The steering system 220 includes, for example, a steering ECU and an electric motor. The electric motor applies force to, for example, a rack-and-pinion mechanism to change the direction of the steering wheel. The steering ECU drives the electric motor based on information input from the second control unit 160 or from the driving operating element 80 to change the direction of the steering wheel.

[0067] The third control unit 180 determines whether the vehicle is predicted to leave the lane while traveling on a curve (departure determination). More specifically, the third control unit 180 identifies the positional relationship between the lane and the vehicle, as well as the vehicle's driving state, based on the recognition results of the object recognition device 16, the detection results of the vehicle sensor 40, and map information (first map information and / or second map information). Based on these recognition results, the third control unit 180 predicts the time it will take for the vehicle to leave the lane if it continues traveling on the curve under the current driving state (hereinafter referred to as TTLC (Time to Lane Crossing)). If the predicted TTLC is less than a predetermined time, the third control unit 180 determines that there is a high probability that the vehicle will leave the lane.

[0068] Typically, when a vehicle is traveling on a curve, the steering angle and vehicle speed are controlled by the driver or a control function to prevent the vehicle from leaving the lane. Such control changes at any time depending on the condition of the vehicle traveling on the curve, changes in curvature, etc. Therefore, the third control unit 180 repeatedly performs the departure determination according to each prescribed control cycle while the vehicle is traveling on the curve. The third control unit 180 may also be configured to perform prescribed processing based on the result of the departure determination. For example, the third control unit 180 may also be configured to, if it predicts that the vehicle will leave, report this to the occupants via the HMI 30 or the navigation device 50. In addition, for example, the third control unit 180 may also be configured to, if it predicts that the vehicle will leave, control the vehicle speed and steering angle in cooperation with the first control unit 120 and the second control unit 160 to prevent the vehicle from leaving the lane.

[0069] [Basic flow of separation judgment]

[0070] Figure 4 This is a flowchart showing an example of the flow of basic processing in departure determination. Figure 5 This is a schematic diagram for explaining the outline of the separation determination. Figure 5 right Figure 4 The process of processing is described below. First, the third control unit 180 obtains lane information for the lane in which the vehicle is traveling (S101). Lane information is information that represents the dividing line of the traveling lane as a point group at a specified interval. It should be noted that when the interval of the point group is too large, the accuracy of the departure judgment decreases. On the other hand, when the interval of the point group is too short, the control cycle of the departure judgment becomes shorter and the processing load increases. Therefore, the interval of the point group is preferably designed to be an appropriate interval (for example, 1m interval, etc.) based on the processing performance, the desired judgment accuracy, etc. In addition, when the dividing line as the processing object in each control cycle is too long (that is, there are too many point groups), the processing load increases. On the other hand, when the dividing line as the processing object is too short, the prediction of lane departure becomes difficult. Therefore, the length of the dividing line as the processing object in each control cycle is preferably designed to be an appropriate length (for example, 100m, etc.) based on the processing performance, the predictability of lane departure, etc. For example, as Figure 5 As shown, for the dividing lines farther from the center of curvature of the curve, lane information is preferably acquired as a set Pn={P1, P2, P3, ...} of coordinates representing the relative position of the vehicle. This set Pn is hereinafter referred to as the dividing line point group Pn.

[0071] Next, the third control unit 180 calculates the predicted path of the host vehicle based on the vehicle speed and yaw rate (S102) and determines whether the predicted path intersects the dividing line (S103: Intersection Determination). If it is determined that the predicted path does not intersect the dividing line, that is, if there is no intersection between the predicted path and the dividing line, the third control unit 180 ends the departure determination for that cycle. On the other hand, if it is determined in S103 that the predicted path intersects the dividing line, that is, if there is an intersection between the predicted path and the dividing line, the third control unit 180 calculates the predicted time until the host vehicle reaches the position of the intersection (TTLC) (S104) and determines whether the TTLC is below a predetermined threshold (S105). If it is determined that the predicted time is greater than the threshold, the third control unit 180 ends the departure determination for that cycle. On the other hand, when it is determined in S105 that the predicted time is equal to or less than the threshold, the third control unit 180 notifies that the vehicle is leaving the lane ( S106 : departure notification) and ends the departure determination of this cycle.

[0072] Figure 5 This is an example of a case where the predicted path R of the vehicle intersects at the line segment S7 formed by P7 and P8 in the dividing line point group Pn. In this case, the third control unit 180 calculates the predicted path R of the vehicle and determines whether or not the line segments n (n=1, 2, ...) formed by two adjacent points of the dividing line point group Pn intersect with the predicted path R in order, starting from the line segment closest to the vehicle. Here, the line segment n is the line segment formed by Pn and Pn+1. Figure 5 In the example of , the third control unit 180 sequentially determines whether line segment S1 (n=1) intersects with the predicted path R (intersection determination). This allows the third control unit 180 to detect the intersection B of the predicted path R and the dividing line at line segment S7 (n=7). Hereinafter, the point where the predicted path intersects the dividing line is referred to as a "departure point." The third control unit 180 can calculate the time required for the vehicle to reach the departure point B from the initial position as TTL C.

[0073] More specifically, the third control unit 180 calculates the movement trajectory of the part of the vehicle that is most likely to intersect (depart from) the dividing line first (hereinafter referred to as the "target part") as the predicted path R of the vehicle. Here, as an example, the outer end of the right front tire of the vehicle is used as the target part, but other parts can also be used as the target part if the same point of view is used. For example, the contact point of the right front tire can be used as the target part, and the right end of the front side of the vehicle body can also be used as the target part. The third control unit 180 can calculate the distance d from the initial position A of the target part to the separation point B (hereinafter referred to as the "separation path length"), and calculate the TTLC by dividing the separation path length d by the moving speed of the target part.

[0074] Return to Figure 4 . The notification of S105 (hereinafter referred to as "departure notification") may be in the form of information display based on HMI30 and navigation device 50, or may be in the form of sound output based on navigation device 50. In addition, the form of departure notification may also be the output of the judgment result to other functional units (for example, the first control unit 120, the second control unit 160, etc.). In this case, the other functional units may be configured to receive the departure notification and perform prescribed actions. For example, the first control unit 120 may be configured to generate a target trajectory that suppresses lane departure according to the driving state of the vehicle at that time when the departure notification is received. In addition, for example, the second control unit 160 may be configured to implement speed control and / or steering control when the departure notification is received so as to suppress lane departure according to the driving state of the vehicle at that time.

[0075] It should be noted that when the TTLC threshold is too high, the threshold for departure notifications is lowered, causing even situations requiring minimal attention to be notified. Distance notifications that require high attention may be mixed with other departure notifications, increasing the risk of danger. Furthermore, when the TTLC threshold is too high, the frequency of departure notifications increases, potentially increasing occupant annoyance. On the other hand, when the TTLC threshold is too low, the time margin between receiving a departure notification and resuming the vehicle's behavior is eliminated, potentially increasing the risk of danger. Therefore, the TTLC threshold is preferably designed to an appropriate value (e.g., 1 second) based on occupant comfort and safety.

[0076] Furthermore, if the control cycle is too short, the number of point clusters that can be processed decreases. On the other hand, if the control cycle is too long, lane departure cannot be detected at the required timing. Therefore, the control cycle is preferably designed to an appropriate value (e.g., 10 milliseconds) based on the number of point clusters to be processed within a cycle and the required detection timing for lane departure. Each of the above design elements is appropriately set to achieve an appropriate combination of values ​​by taking into account other design elements.

[0077] [Vehicle's turning speed and turning center]

[0078] Figure 6 1 is a diagram illustrating a method for calculating the turning speed and turning center of the vehicle when traveling along a curve in the departure judgment. Figure 5 As described in [1], calculation of the departure path length requires prediction of the vehicle's travel path. A vehicle traveling on a curve (curvature X) is considered to be turning on the circumference of the curvature X. Therefore, in this embodiment, to predict the vehicle's travel path, the position of the center of the turning motion (turning center) is first determined. Figure 6 This shows the situation where the vehicle is turning at a speed v about a turning center O. The vehicle's moving direction is the direction of the normal (the direction of vector v) at a point G on a circle with a radius from the turning center O to the center (center of gravity) G of the vehicle. Figure 6 The xy coordinate system in the figure is an orthogonal coordinate system with the center G of the vehicle as its origin, and the x-axis is an axis parallel to the front direction of the vehicle. In this case, the speed v of the position change of the target part (hereinafter referred to as the tire) is tyre It can be expressed by the following formula (1).

[0079] [Formula 1]

[0080]

[0081] In formula (1), v x＿tyre is the speed v tyre The x-direction component, vy＿tyre is the speed v tyre The y-direction component of the vehicle. In addition, RateYaw is the yaw angular velocity of the vehicle's turning motion. In addition, v x is the x-direction component of the velocity v of the center G of the vehicle, v y is the y-direction component. Tx is the x-coordinate component of the tire's position, and Ty is the y-coordinate component. Equation (1) is obtained by synthesizing rotational motion and translational motion based on the motion equation of a rigid body. In this case, the turning radius of the tire can be expressed by the following equation (2).

[0082] [Formula 2]

[0083]

[0084] Figure 7 、 Figure 8 、 Figure 9 This diagram illustrates a method for calculating the length of the departure path for a vehicle traveling on a curve during departure determination. More specifically, the method for calculating the departure path length includes a first step for determining the first coordinates, a second step for determining the second coordinates, and a third step for determining the departure path length based on the results of the first and second steps. Figure 7 、 Figure 8 、 Figure 9 The moving trajectory (i.e., predicted path) of the tire of the vehicle that is turning with the turning center O as the center is the difference between the two adjacent points (P Beg and P End ) intersect at the separation point C. Hereinafter, this line segment is referred to as a "crossing line segment."

[0085] Figure 7 1 is a diagram illustrating a method for calculating the first coordinate in the first step. In the first step, the third control unit 180 obtains P Beg The coordinates of the third vertex D of the right triangle with the turning center O as the second vertex are projected (first coordinates). Here, the first vertex P Beg The coordinates of the second vertex O (v c ) is based on the initial position of the tire, through Figure 6 The tire moving speed v obtained by the method described above tyre and turning radius R tyre In this case, the third control unit 180 can obtain the inner product of the vectors as shown in the following formula (3) to obtain the known value from the first vertex P Beg The ratio of the length to the third vertex D to the length of the intersection segmenth .

[0086] [Formula 3]

[0087]

[0088] In formula (3), v s It is from P Beg Towards P End vector, v p It is from P Beg The vector pointing toward the turning center O. φ is the vector v s With v p Next, the third control unit 180 calculates the angle based on the ratio obtained in formula (3). h By performing vector calculation of the following formula (4), the coordinates projected of the third vertex D can be obtained.

[0089] [Formula 4]

[0090] projected=segBeg+ratio h *v s …(4)

[0091] Figure 8 is a diagram illustrating a method for calculating the second coordinate in the second step. In the second step, the third control unit 180 calculates the coordinates (second coordinates) of the departure point C based on the first coordinate (projected) calculated in the first step. First, the third control unit 180 calculates the distance s from the turning center O to the third vertex D using the following formula (5). In formula (5), v c are the coordinates of the turning center O.

[0092] [Formula 5]

[0093] s=|projected-v c | …(5)

[0094] Next, the third control unit 180 calculates the distance t from the separation point C to the third vertex D using the following formula (6). In formula (6), R tyre is the turning radius of the tire T obtained in equation (2).

[0095] [Formula 6]

[0096]

[0097] Next, the third control unit 180 can obtain the coordinates of the departure point C (departurePoint) using the following formula (7).

[0098] [Formula 7]

[0099]

[0100] Figure 9 This is a diagram illustrating a method for calculating the length d of the escape path in the third step. First, the third control unit 180 calculates the angle θ between the line segment connecting the turning center O and the escape point C and the straight line L passing through the turning center O and parallel to the y-axis using the following formula (8): Dep In formula (8), v x The length of the perpendicular line from the departure point C to the straight line L is based on the y coordinate of the turning center O, the y coordinate of the departure point C, and the turning radius R. tyre To calculate. In addition, v y It is the length of the line segment connecting the foot of the perpendicular line and the turning center O, and is calculated based on the y coordinate of the turning center O and the y coordinate of the departure point C.

[0101] [Formula 8]

[0102]

[0103] Next, the third control unit 180 calculates the angle θ between the line segment connecting the turning center O and the initial position of the tire T and the straight line L using the following formula (9): ini When the straight line L is used as a reference and the turning direction is regarded as the positive direction, θ Dep becomes a positive angle, θ ini becomes a negative angle, so from θ obtained by formula (8) Dep Subtract θ ini The difference is the angle at which the vehicle turns from the initial position (the initial position of the tire T) to the departure point C. In formula (9), v x ′ v is the length of the perpendicular line from the initial position to the straight line L, which is calculated based on the x-coordinate of the initial position and the x-coordinate of the turning center O. y ′ It is the length of the line segment connecting the foot of the perpendicular line and the turning center O, and is calculated based on the y coordinate of the initial position and the y coordinate of the turning center O.

[0104] [Formula 9]

[0105]

[0106] Then, the third control unit 180 can calculate the escape path length d by the following formula (10).

[0107] [Formula 10]

[0108] d=R tyre (θ Dep-θ Ini ) …(10)

[0109] The third control unit 180 can control the deviation path based on the deviation path length d and the turning speed v obtained as described above. tyre , calculate the time required for the vehicle to reach the departure point C from the initial position (i.e. TTLC). It should be noted that when the vehicle is traveling on a curve, θ ini Become the ratio θ Dep In this case, the third control unit 180 can control the value of θ by setting the value of θ to the value of θ within the limit allowed by the accuracy of the separation determination. ini It is approximated to zero to reduce the amount of calculation, thereby reducing the processing load of the separation judgment. ini Approximating to zero means obtaining the initial position of the tire T on the straight line L. Thus, the third control unit 180 sets the turning center O to the side of the vehicle.

[0110] According to the embodiment described above, the departure determination can be performed based on the predicted path of the host vehicle in turning motion, and therefore the departure determination when the host vehicle is traveling on a curve can be performed more appropriately.

[0111] It should be noted that, in the above-mentioned embodiment, the case where the separation determination is implemented when the vehicle is traveling on a curve is described, but the separation determination of the above-mentioned method can also be implemented when the vehicle is traveling other than on a curve. In this case, the third control unit 180 can calculate the predicted path of the vehicle by a method different from the above-mentioned method. For example, when the vehicle is traveling in a roughly straight line (when the yaw angular velocity is sufficiently small), the third control unit 180 can calculate the predicted path based on the vehicle speed, acceleration, direction of travel, etc. of the vehicle. In addition, for example, the third control unit 180 can also use information on the path that the vehicle traveled before the current control cycle in the calculation of the predicted path.

[0112] In the above embodiment, the initial position of the host vehicle is set as the position of the front tire T away from the center of the turn, and the predicted path is calculated with this initial position as the starting point. However, the position of the tire T may also be the contact point, and the initial position may also be set at the front end of the vehicle body close to the tire T. In other words, the initial position of the host vehicle may be the end of the vehicle body or the contact point close to the intersection or the contact point. In this case, if θ ini If the angle is sufficiently small, the turning center O can be said to be set in a vertical direction perpendicular to the front direction of the vehicle from the end portion close to the intersection or the ground contact point.

[0113] The above-described embodiment can be expressed as follows.

[0114] A vehicle control device, wherein:

[0115] The vehicle control device comprises:

[0116] a storage device storing a program; and

[0117] Hardware processor,

[0118] The hardware processor executes the program to perform the following processing:

[0119] Identify the dividing lines of the road on which the vehicle is traveling;

[0120] Calculating a predicted path for the vehicle based on the vehicle's driving state;

[0121] determining whether or not the dividing line intersects the predicted path for each predetermined section of the dividing line; and

[0122] When it is determined that the predicted path intersects the dividing line of the predetermined section, the remaining time until the vehicle reaches the intersection of the predicted path and the dividing line is calculated. When the remaining time is equal to or less than a threshold, it is determined that there is a high possibility that the vehicle has deviated from the dividing line.

[0123] While specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and various modifications and substitutions can be made without departing from the spirit of the present invention.

Claims

1. A vehicle control device, wherein: The vehicle control device comprises: a recognition unit that recognizes a dividing line of a road on which the host vehicle is traveling; a prediction unit that calculates a predicted path of the host vehicle based on the driving state of the host vehicle; an intersection determination unit that determines whether or not the dividing line intersects the predicted path for each predetermined section of the dividing line; and The determination unit calculates a surplus time until the vehicle reaches the intersection of the predicted path and the dividing line when it is determined that the predicted path intersects the dividing line of the predetermined section, and determines that there is a high possibility that the vehicle will deviate from the dividing line when the surplus time is equal to or less than a threshold.

2. The vehicle control device according to claim 1, wherein: The intersection determination unit calculates the predicted path using a turning curve obtained based on the current driving state of the vehicle when the vehicle is traveling with a turning motion.

3. The vehicle control device according to claim 1, wherein: The determination unit calculates the margin time using a turning curve obtained based on a current driving state of the vehicle when the vehicle is traveling with a turning motion.

4. The vehicle control device according to claim 2 or 3, wherein: The center of the turning curve is set to the side of the vehicle.

5. The vehicle control device according to claim 4, wherein: The center is set in a direction perpendicular to the front direction of the host vehicle from one of the end portion or the ground contact point of the host vehicle, which is close to the predetermined section or the ground contact point.

6. A vehicle control method, wherein: The control device of this vehicle performs the following processing: Identify the dividing lines of the road on which the vehicle is traveling; Calculating a predicted path for the vehicle based on the vehicle's driving state; determining whether or not the dividing line intersects the predicted path for each predetermined section of the dividing line; and When it is determined that the predicted path intersects the dividing line of the predetermined section, the remaining time until the vehicle reaches the intersection of the predicted path and the dividing line is calculated. When the remaining time is equal to or less than a threshold, it is determined that there is a high possibility that the vehicle has deviated from the dividing line.

7. A storage medium, which is a non-transitory storage medium readable by a computer, wherein: The storage medium stores a program, The program is used to cause the control device of the vehicle to perform the following processing: Identify the dividing lines of the road on which the vehicle is traveling; Calculating a predicted path for the vehicle based on the vehicle's driving state; determining whether or not the dividing line intersects the predicted path for each predetermined section of the dividing line; and When it is determined that the predicted path intersects the dividing line of the predetermined section, the remaining time until the vehicle reaches the intersection of the predicted path and the dividing line is calculated. When the remaining time is equal to or less than a threshold, it is determined that there is a high possibility that the vehicle has deviated from the dividing line.

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