Vehicle control device, vehicle control computer program, and vehicle control method

Abstract

To provide a vehicle control device that can inhibit deviation from the lane marking lines of the lane in which the vehicle is traveling.SOLUTION: A vehicle control device comprises: a determining unit 232 configured to determine a target torque as a target for driver torque at which generation of anti-torque on a steering wheel is to be initiated, on the basis of a reference torque as a reference for driver torque at which generation of anti-torque is to be initiated against the driver torque produced by operation of the steering wheel by a driver, and a current correction value for the reference torque; a counting unit 233 configured to count a number of deviations from a lane marking line of a lane in which a vehicle is traveling while the driver torque exceeds the target torque; and a calculating unit 234 configured to calculate a new correction value for the reference torque on the basis of a correction coefficient that is set on the basis of the number of deviations. The determining unit 232 determines a next target torque on the basis of the reference torque and the new correction value for the reference torque.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a vehicle control device, a computer program for controlling a vehicle, and a vehicle control method. [Background technology]

[0002] An automatic control system installed in a vehicle generates a navigation route for the vehicle based on the current position of the vehicle, the destination position of the vehicle, and a navigation map. The automatic control system estimates the current position of the vehicle using map information and controls the vehicle to travel along the navigation route.

[0003] When the driver operates the steering wheel during automatic control operation, the automatic control system detects the driver torque, which is the rotational force that rotates the steering wheel, and generates a counter torque that rotates the steering wheel in the opposite direction to the driver's operation in response to this driver torque.

[0004] When the automatic control system detects a driver torque equal to or greater than a reference torque that is a reference for the driver torque at which a counter torque is to be generated in the steering wheel, the automatic control system starts to apply a counter torque to the steering wheel. As the driver torque increases, the counter torque also increases, so the driver can be aware of the magnitude of the driver torque with which he or she is operating the steering wheel.

[0005] In this way, the automatic control system allows the driver to perform steering operation, and makes the driver aware that the automatic control system is controlling the steering.

[0006] Patent Document 1 proposes a vehicle operation reaction force control device that reduces the driving burden by controlling the reaction force of an operation mechanism of a vehicle, such as a steering wheel, in accordance with individual differences between drivers. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2008-296605 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, even if the magnitude of the counter torque is changed according to the force applied by each driver when steering, if the standard for starting to apply the counter torque to the steering wheel is not appropriate, the timing at which the driver realizes that he or she is steering may be delayed, which may result in the driver unconsciously steering the steering wheel and causing the vehicle to deviate from the lane markings of the lane in which the vehicle is traveling.

[0009] Therefore, an object of the present disclosure is to provide a vehicle control device that can suppress deviation from lane markings of the lane in which the vehicle is traveling in accordance with each individual driver. [Means for solving the problem]

[0010] According to one embodiment, there is provided a vehicle control device, which includes a target torque determination unit that determines a target torque for the driver torque that starts generating an anti-torque to the driver torque generated by the driver's operation of the steering wheel, based on a reference torque that is a reference for the driver torque that starts generating an anti-torque to the driver torque generated by the driver's operation of the steering wheel and a current correction value for the reference torque, a counting unit that counts the number of departures in which the vehicle deviates from a lane marking of the lane on which the vehicle is traveling in a state in which the driver torque exceeds the target torque, and a correction value calculation unit that calculates a new correction value for the reference torque, based on a correction coefficient that is determined based on the number of departures, and the target torque determination unit determines a next target torque based on the reference torque and the new correction value for the reference torque.

[0011] In addition, it is preferable that this vehicle control device has a change amount calculation unit that calculates the amount of change in driver torque relative to the target torque, and the correction value calculation unit calculates a new correction value for the reference torque based on the correction coefficient and the amount of change in driver torque.

[0012] In addition, in this vehicle control device, it is preferable that the correction value calculation unit calculates a second correction value based on the distance traveled by the vehicle in a state where the driver torque exceeds the target torque and the number of departures is not counted, and the correction value calculation unit calculates a correction value for the reference torque based on the correction value and the second correction value.

[0013] In addition, in this vehicle control device, it is preferable that the relationship between the correction coefficient and the number of departures has a first region in which the correction coefficient increases as the number of departures increases, a second region in which the correction coefficient increases as the number of departures increases more than in the first region, and a third region in which the correction coefficient increases as the number of departures increases less than in the second region.

[0014] According to another embodiment, there is provided a computer program for controlling a vehicle, which includes causing a processor to execute a process including: determining a target torque for the driver torque at which an anti-torque is to be generated on the steering wheel, based on a reference torque serving as a reference for the driver torque at which an anti-torque is to be generated against a driver torque generated by a steering wheel operation by a driver and a current correction value for the reference torque; counting the number of departures from a lane marking of the lane in which the vehicle is traveling in a state in which the driver torque exceeds the target torque; and determining a new correction value for the reference torque based on a correction coefficient determined based on the number of departures; and determining a next target torque based on the reference torque and the new correction value for the reference torque.

[0015] According to yet another embodiment, there is provided a vehicle control method, which is executed by a vehicle control device, and includes determining a target torque as a target for the driver torque at which an anti-torque is to be generated on the steering wheel, based on a reference torque as a reference for the driver torque at which an anti-torque is to be generated against a driver torque generated by an operation of the steering wheel by a driver and a current correction value for the reference torque, counting the number of departures from a lane marking of the lane on which the vehicle is traveling in a state in which the driver torque exceeds the target torque, and determining a new correction value for the reference torque based on a correction coefficient determined based on the number of departures, and is characterized in that the next target torque is determined based on the reference torque and the new correction value for the reference torque. Effect of the Invention

[0016] The vehicle control device of the present disclosure determines the timing of generating a counter torque in accordance with the driver's past steering wheel operation, thereby making the driver aware that he or she is steering, and thus can prevent the vehicle from deviating from the lane markings of the lane in which the vehicle is traveling in accordance with the individual driver. [Brief description of the drawings]

[0017] [Figure 1] 1A and 1B are diagrams for explaining an overview of the operation of the torque control device of this embodiment, in which (A) is a diagram showing a vehicle traveling on a road, (B) is a diagram for explaining the relationship between the driver torque and the target torque, and (C) is a diagram for explaining a new target torque. [Diagram 2] 1 is a schematic configuration diagram of a vehicle in which a vehicle control system according to an embodiment of the present invention is implemented. [Diagram 3] 4 is an example of an operational flowchart relating to a target torque determination process of the torque control device of the present embodiment. [Figure 4] 4 is an example of an operational flowchart relating to a first correction value calculation process of the torque control device of the present embodiment. [Diagram 5]FIG. 11 is a diagram illustrating an example of a relationship between a correction coefficient and the number of deviations. [Figure 6] 5 is an example of an operational flowchart relating to a second correction value calculation process of the torque control device of the present embodiment. [Figure 7] FIG. 11 is a diagram illustrating an example of a relationship between a correction value and a travel distance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Figures 1(A) to 1(C) are diagrams for explaining an outline of the operation of the torque control device of this embodiment. Figure 1(A) is a diagram showing a state in which a vehicle runs on a road. Figure 1(B) is a diagram for explaining the relationship between the driver torque and the target torque. Figure 1(C) is a diagram for explaining a new target torque.

[0019] Hereinafter, an overview of the operation of the vehicle control process of the operation planning device 15 disclosed in this specification will be described with reference to Figs. 1(A) to 1(C).

[0020] 1(A), a vehicle 10 is traveling on a lane 51 of a road 50 having lanes 51 and 52. The lanes 51 and 52 are separated by a lane dividing line 53.

[0021] The vehicle 10 driven by automatic control has a user interface (UI) 5 and a torque control device 17. When a driver operates a steering wheel (not shown), the torque control device 17 detects a driver torque, which is a rotational force that rotates the steering wheel. In response to the driver torque, the torque control device 17 generates a counter torque in the steering wheel, which is a rotational force that rotates the steering wheel in the opposite direction to the driver's operation.

[0022] As shown in FIG. 1(A), the driver intended to simply place his hands on the steering wheel, but the driver operated the steering wheel, causing the vehicle 10 to deviate from the lane marking 52 of the lane 51 in which the vehicle 10 is traveling.

[0023] Fig. 1(B) shows the change over time of the driver torque of the vehicle 10 shown in Fig. 1(A). The vertical axis shows the absolute value of the torque. Because the value of the driver torque, which is the reference for starting to apply the counter torque to the steering wheel, is large, the timing at which the counter torque is applied to the steering wheel is delayed. Therefore, even if the counter torque increases together with the driver torque, the timing at which the driver realizes that he is steering is delayed.

[0024] When the torque control device 17 detects the driver torque, it determines a target torque that is a target of the driver torque at which a counter torque is started to be generated on the steering wheel, based on a reference torque and a current correction value for the reference torque. Here, the reference torque is the magnitude of the torque that is a reference for the live torque at which a counter torque is started to be generated on the steering wheel. When the torque control device 17 detects a driver torque at or above the target torque on the steering wheel, it starts applying a counter torque to the steering wheel. As shown in FIG. 1(B), the rotation of the steering wheel of the vehicle 10 is generated by an actual torque that is the difference between the driver torque and the counter torque.

[0025] Because the driver torque has reached the target torque, the torque control device 17 starts to generate a counter torque on the steering wheel. The direction in which the counter torque rotates the steering wheel is opposite to the direction in which the steering wheel is rotated by the driver torque. The torque control device 17 controls the magnitude of the counter torque according to the magnitude of the driver torque generated on the steering wheel.

[0026] However, because the timing of the generation of the counter torque was late, the driver operated the steering wheel, steering the vehicle 10 to the right, causing the vehicle 10 to deviate from the lane marking 52.

[0027] The torque control device 17 notifies the driver via the UI 5 that the vehicle 10 has departed from the lane marking 52. In addition, the torque control device 17 may notify the driver that the vehicle 10 has departed from the lane marking 52 and may request that the driving of the vehicle 10 be transferred from automatic control to the driver.

[0028] The driver, who has been notified that the vehicle 10 has departed from the lane markings 52, applies a driver torque to the steering wheel to steer the vehicle 10 to the left. The direction of the driver torque is opposite to that when steering the vehicle 10 to the right. The torque control device 17 continues to apply a counter torque to the steering wheel in response to the driver torque.

[0029] As the vehicle 10 moves toward the center of the lane 51, the driver torque applied to the steering wheel by the driver is reduced. Also, as the driver torque is reduced, the counter torque is reduced. The driver stops steering the steering wheel as the vehicle 10 returns to the center of the lane 51. The torque control device 17 stops applying the counter torque to the steering wheel as the driver torque is no longer present.

[0030] The torque control device 17 counts the number of times the vehicle 10 deviates from the lane markings 53 of the lane 51 on which the vehicle 10 is traveling, while the driver torque exceeds the target torque. Then, the torque control device 17 calculates a new correction value for the reference torque based on a correction coefficient determined based on the number of deviations.

[0031] As shown in FIG. 1(C), the torque control device 17 determines the next target torque based on the reference torque and a new correction value for the reference torque when the driver torque is detected next time. The next target torque is lower than the previous value, and changes so that a counter torque occurs at an earlier timing. This allows the driver to be aware that the steering wheel is to be steered at an earlier timing.

[0032] As described above, by determining the standard for starting to apply a counter torque to the steering wheel in accordance with the driver's past steering wheel operation, the driver becomes aware that he or she is steering, and therefore, deviation from the lane markings of the lane in which the vehicle 10 is traveling can be prevented in accordance with the individual driver.

[0033] 2 is a schematic configuration diagram of a vehicle 10 in which the vehicle control system 1 of the present embodiment is implemented. The vehicle 10 includes a camera 2, a positioning information receiver 3, a navigation device 4, a user interface (UI) 5, a torque detection device 6, a map information storage device 11, a position estimation device 12, an object detection device 13, a driving lane planning device 14, a driving planner 15, a vehicle control device 16, a torque control device 17, and the like. Furthermore, the vehicle 10 may include a distance measurement sensor (not shown) such as a millimeter wave radar for measuring distances to objects around the vehicle 10.

[0034] The camera 2, the positioning information receiver 3, the navigation device 4, the UI 5, the torque detection device 6, the map information storage device 11, the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planning device 15, the vehicle control device 16, and the torque control device 17 are communicatively connected via an in-vehicle network 18 that complies with a standard such as a controller area network.

[0035] The camera 2 is an example of an imaging unit provided on the vehicle 10. The camera 2 is attached to the vehicle 10 so as to face forward of the vehicle 10. The camera 2 captures camera images showing the environment of a predetermined area ahead of the vehicle 10, for example, at a predetermined period. The camera images may show the road included in the predetermined area ahead of the vehicle 10 and road features such as lane markings on the road surface. The camera 2 has a two-dimensional detector composed of an array of photoelectric conversion elements sensitive to visible light, such as a CCD or C-MOS, and an imaging optical system that forms an image of the area to be captured on the two-dimensional detector.

[0036] Every time the camera 2 captures a camera image, it outputs the camera image and the camera image capture time at which the camera image was captured to the position estimation device 12, the object detection device 13, etc. via the in-vehicle network 18. The camera image is used by the position estimation device 12 in a process of estimating the position of the vehicle 10. The camera image is also used by the object detection device 13 in a process of detecting other objects around the vehicle 10.

[0037] The positioning information receiver 3 outputs positioning information indicating the current position of the vehicle 10. For example, the positioning information receiver 3 may be a GNSS receiver. Every time the positioning information receiver 3 acquires positioning information at a predetermined reception cycle, the positioning information receiver 3 outputs the positioning information and the positioning information acquisition time when the positioning information was acquired to the navigation device 4, the map information storage device 11, etc.

[0038] The navigation device 4 generates a navigation route from the current position of the vehicle 10 to the destination position based on the navigation map information, the destination position of the vehicle 10 input from the UI 5, and the positioning information indicating the current position of the vehicle 10 input from the positioning information receiver 3. The navigation route includes information regarding the positions of right turns, left turns, merging, and branching. The navigation device 4 generates a new navigation route for the vehicle 10 when a new destination position is set or when the current position of the vehicle 10 deviates from the navigation route. Every time the navigation device 4 generates a navigation route, it outputs the navigation route to the position estimation device 12, the driving lane planning device 14, and the like via the in-vehicle network 18.

[0039] The UI5 ​​is an example of a notification unit. The UI5 ​​is controlled by the navigation device 4, the driving plan device 15, the vehicle control device 16, the torque control device 17, and the like, and notifies the driver of the driving information of the vehicle 10 and the like. The driving information of the vehicle 10 includes information on the current and future routes of the vehicle, such as the current position of the vehicle and a navigation route. The UI5 ​​may also notify the driver of information indicating that the vehicle 10 has deviated from a lane marking, and a request to transfer the subject of driving the vehicle 10 from the automatic control system to the driver, and the like. The UI5 ​​has a display device 5a such as a liquid crystal display or a touch panel to display the driving information and the like. The UI5 ​​may also have an audio output device (not shown) for notifying the driver of the driving information and the like. The UI5 ​​generates an operation signal according to an operation from the driver to the vehicle 10. Examples of the operation information include a destination position, a waypoint, the speed of the vehicle, and other control information. The UI5 ​​has, for example, a touch panel or an operation button as an input device for inputting the operation information from the driver to the vehicle 10. The UI 5 outputs the input operation information to the navigation device 4, the driving planning device 15, the vehicle control device 16, etc. via the in-vehicle network 18.

[0040] The torque detector 6 detects the force that rotates the rotation shaft of the steering wheel, which is generated by the operation of the steering wheel by the driver, and outputs a signal representing the rotating force to the torque control device 17 etc. The torque detector 6 may also detect the angle and angular velocity of the rotation shaft of the steering wheel.

[0041] The map information storage device 11 stores map information of a relatively wide area (for example, a range of 10 to 30 km square) including the current position of the vehicle 10. This map information has high-precision map information including three-dimensional information of the road surface, road speed limits, road curvature, road features such as lane markings on the road, and information indicating the types and positions of structures. The positions of lane markings and the like in the map information are represented, for example, in a world coordinate system having an origin at a predetermined position.

[0042] The map information storage device 11 receives wide-area map information from an external server via a base station by wireless communication via a wireless communication device (not shown) mounted on the vehicle 10 according to the current position of the vehicle 10, and stores the received map information in the storage device. Every time positioning information is input from the positioning information receiver 3, the map information storage device 11 refers to the stored wide-area map information, and outputs map information of a relatively small area (for example, a range of 100 m square to 10 km square) including the current position represented by the positioning information to the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planning device 15, the vehicle control device 16, etc. via the in-vehicle network 18.

[0043] The position estimation device 12 estimates the position of the vehicle 10 at the time the camera image is captured, based on road features around the vehicle 10 shown in the camera image captured by the camera 2. For example, the position estimation device 12 compares lane markings identified in the camera image with lane markings shown in the map information input from the map information storage device 11, and determines an estimated position and an estimated azimuth angle of the vehicle 10 at the time the camera image is captured. The position estimation device 12 also estimates the driving lane on the road on which the vehicle 10 is located, based on the lane markings shown in the map information, and the estimated position and estimated azimuth angle of the vehicle 10. Every time the position estimation device 12 determines the estimated position, estimated azimuth angle, and driving lane of the vehicle 10 at the time the camera image is captured, it outputs this information to the object detection device 13, the driving lane planning device 14, the driving planner 15, the vehicle control device 16, etc. Each time the position estimation device 12 calculates the estimated position, estimated azimuth angle, and driving lane of the vehicle 10 at the time an image was captured by the camera, it outputs the position of the vehicle 10 and the position of the lane markings shown in the map information to the torque control device 17.

[0044] The object detection device 13 detects other objects and their types (e.g., vehicles) around the vehicle 10 based on the camera image. The other objects include other vehicles traveling around the vehicle 10. The object detection device 13 tracks the detected other objects to obtain the trajectory of the other objects. The object detection device 13 identifies the driving lane in which the other object is traveling based on the lane dividing lines shown in the map information and the position of the other object. In addition, the object detection device 13 outputs object detection information including information indicating the type of the detected other object, information indicating its position, and information indicating the driving lane to the driving lane planning device 14, the driving planning device 15, etc.

[0045] The driving lane planning device 14 generates a driving lane plan representing a planned driving lane on which the vehicle 10 will travel, based on map information, the navigation route and surrounding environment information, and the current position of the vehicle 10, in the nearest driving section (e.g., 10 km) selected from the navigation route at a driving lane plan generation time set at a predetermined cycle. The driving lane planning device 14 generates a driving lane plan so that the vehicle 10 travels on a lane other than an overtaking lane, for example. The driving lane planning device 14 outputs the driving lane plan to the driving planning device 15 every time it generates a driving lane plan.

[0046] The driving plan device 15 executes a driving plan process to generate a driving plan representing a planned driving trajectory of the vehicle 10 up to a predetermined time (for example, 5 seconds) ahead based on a driving lane plan, map information, the current position of the vehicle 10, surrounding environment information, and vehicle state information at a driving plan generation time set at a predetermined cycle. The surrounding environment information includes the positions and speeds of other vehicles traveling around the vehicle 10. The vehicle state information includes the current position, vehicle speed, acceleration, and traveling direction of the vehicle 10. The driving plan is expressed as a set of the target position of the vehicle 10 and the target vehicle speed at the target position at each time from the current time to the predetermined time ahead. The cycle in which the driving plan is generated is preferably shorter than the cycle in which the driving lane plan is generated. The driving plan device 15 generates a driving plan so that a distance of a predetermined distance or more can be maintained between the vehicle 10 and other objects (vehicles, etc.).

[0047] The vehicle control device 16 controls each part of the vehicle 10 based on the current position, the vehicle speed, and the yaw rate of the vehicle 10, and the driving plan generated by the driving plan device 15. For example, the vehicle control device 16 obtains the steering angle, acceleration, and angular acceleration of the vehicle 10 according to the driving plan, the vehicle speed, and the yaw rate of the vehicle 10, and sets the steering amount, accelerator opening, or brake amount so as to obtain the steering angle, acceleration, and angular acceleration. Then, the vehicle control device 16 outputs a control signal corresponding to the set steering amount to an actuator (not shown) that controls the steered wheels of the vehicle 10 via the in-vehicle network 18. Also, the vehicle control device 16 outputs a control signal corresponding to the set accelerator opening to a drive device (engine or motor) of the vehicle 10 via the in-vehicle network 18. Alternatively, the vehicle control device 16 outputs a control signal corresponding to the set brake amount to a brake (not shown) of the vehicle 10 via the in-vehicle network 18.

[0048] The torque control device 17 executes a control process, a determination process, a count process, and a calculation process. To that end, the operation planning device 15 has a communication interface (IF) 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 are connected via a signal line 24. The communication interface 21 has an interface circuit for connecting the torque control device 17 to the in-vehicle network 18. The torque control device 17 is an example of a vehicle control device.

[0049] The memory 22 is an example of a storage unit and includes, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores computer programs of applications used in the information processing executed by the processor 23 and various data.

[0050] All or part of the functions of the torque control device 17 are functional modules realized by, for example, a computer program running on the processor 23. The processor 23 has a control unit 231, a determination unit 232, a counting unit 233, and a calculation unit 234. Alternatively, the functional modules of the processor 23 may be dedicated arithmetic circuits provided in the processor 23. The processor 23 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 23 may further have other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphic processing unit.

[0051] The control unit 231 detects the driver torque based on a signal representing the force rotating the steering wheel, input from the torque detection device 6. As shown in FIG. 1B, when the control unit 231 detects a driver torque equal to or greater than the target torque, the control unit 231 controls a drive unit (not shown) that rotates the rotation shaft of the steering wheel so as to apply a counter torque to the steering wheel according to the magnitude of the driver torque. This drive unit is controlled by the control unit 231 to apply the counter torque to the rotation shaft of the steering wheel. The control unit 231 may determine the counter torque based on the angle or angular velocity of the rotation shaft of the steering wheel together with the driver torque. The direction of the counter torque is opposite to that of the driver torque. Other operations of the torque control device 17, including a process for determining the target torque, will be described later.

[0052] The map information storage device 11, the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planner 15, the vehicle control device 16, and the torque control device 17 are, for example, electronic control units (ECUs). In Fig. 2, the map information storage device 11, the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planner 15, the vehicle control device 16, and the torque control device 17 are described as separate devices, but all or some of these devices may be configured as a single device.

[0053] Fig. 3 is an example of an operation flowchart relating to the target torque determination process of the torque control device 17 of this embodiment. The target torque determination process of the torque control device 17 will be described below with reference to Fig. 3. The torque control device 17 executes the target torque determination process according to the operation flowchart shown in Fig. 3 at target torque determination times having a predetermined cycle. The predetermined cycle can be, for example, 0.05 to 0.1 milliseconds.

[0054] First, the determination unit 232 determines whether or not a driver torque has been generated (step S101). The determination unit 232 detects the driver torque based on a signal representing a force rotating the steering wheel, input from the torque detection device 6. The determination unit 232 determines that the driver torque has been generated when a driver torque equal to or greater than a predetermined threshold torque has been generated for a predetermined reference time or longer. The threshold torque is preferably determined to be, for example, a magnitude that is not affected by noise that may be included in the signal input from the torque detection device 6.

[0055] If the driver torque is generated (step S101-Yes), the determination unit 232 determines the target torque based on the reference torque and the current correction value for the reference torque (step S102), and ends the series of processes. The magnitude of the reference torque is the reference for the driver torque that starts to generate a counter torque on the steering wheel according to the driver torque generated on the steering wheel by the operation of the steering wheel by the driver. It is preferable that the magnitude of the reference torque is set so that the operation of the steering wheel by the driver's intention can be detected.

[0056] The magnitude of the target torque is a target for the driver torque at which the counter torque is to be generated in the steering wheel. The correction value includes a first correction value M1 that is determined based on the number of deviations from the lane markings of the lane on which the vehicle is traveling. The control unit 231 determines whether the magnitude of the driver torque has reached the target torque. The determination unit 232 is an example of a target torque determination unit.

[0057] The determination unit 232 determines, as the target torque Tb, a value obtained by subtracting a current first correction value M1, which is determined based on the number of departures, from the reference torque Ta, as shown in the following formula (1).

[0058]

number

[0059] The determination unit 232 may also obtain a correction value for the reference torque by subtracting a current second correction value M2, which is determined based on the distance traveled by the vehicle 10 without counting the number of departures, from the current first correction value M1. In this case, the determination unit 232 obtains a value obtained by adding the current second correction value M2 to the difference between the reference torque Ta and the current first correction value M1 as shown in the following formula (2), as the target torque Tb. The process of obtaining the first correction value M1 and the second correction value M2 will be described later.

[0060]

number

[0061] On the other hand, if the driver torque is not generated (step S101-No), the series of processes ends.

[0062] When it is determined that the driver torque has been generated and the target torque has been determined, it is preferable that the determination unit 232 does not start a new target torque determination process until it is determined that the driver torque has disappeared. When a driver torque equal to or greater than a predetermined threshold torque has not been generated for a predetermined reference time or longer, the determination unit 232 determines that the driver torque has disappeared.

[0063] Next, the first correction value calculation process will be described below with reference to Fig. 4. Fig. 4 is an example of an operation flowchart related to the first correction value calculation process of the torque control device 17 of this embodiment. The torque control device 17 executes the first correction value calculation process in accordance with the operation flowchart shown in Fig. 4 every time the driver torque disappears after it is determined that the driver torque has been generated. Note that the torque control device 17 determines that the driver torque has disappeared when a driver torque equal to or greater than a predetermined threshold torque has not been generated for a predetermined reference time or longer.

[0064] First, the counting unit 233 determines whether or not a counter torque has occurred in the current steering of the steering wheel by the driver (step S201). Even if the driver torque has occurred, if the magnitude of the driver torque is less than the target torque, the counter torque does not occur.

[0065] When a counter torque occurs (step S201-Yes), the counting unit 233 determines whether or not the vehicle 10 has deviated from the lane marking of the lane in which the vehicle 10 is traveling, with the driver torque exceeding the target torque (step S202). The counting unit 233 obtains the positions of the right end and the left end of the vehicle 10 based on the position of the vehicle 10. The positions of the right end and the left end of the vehicle 10 are expressed, for example, in the world coordinate system. The counting unit 233 also compares the positions of the right end and the left end of the vehicle 10 with the positions of the lane markings located on both sides of the current position of the vehicle 10. Then, when the right end of the vehicle 10 has exceeded the position of the lane marking or the left end of the vehicle 10 has exceeded the position of the lane marking, with the driver torque exceeding the target torque, the counting unit 233 determines whether or not the vehicle 10 has deviated from the lane marking of the lane in which the vehicle 10 is traveling. When the driver torque exceeds the target torque, a counter torque is generated.

[0066] If the vehicle 10 deviates from the lane marking of the lane in which the vehicle 10 is traveling (step S202-Yes), the counting unit 233 counts the number of deviations from the lane marking of the lane in which the vehicle 10 is traveling (step S203). The initial value of the deviation number is zero.

[0067] Next, the calculation unit 234 calculates the amount of change in the driver torque with respect to the target torque each time the number of deviations is counted (step S204). The calculation unit 234 is an example of a change amount calculation unit. The calculation unit 234 calculates the amount of change S in the driver torque with respect to the target torque from when it is determined that the driver torque is generated until it is determined that the driver torque is eliminated, using the following formula (3). Here, the start time t1 is the time when the driver torque reaches the target torque, and the end time t2 is the time when the driver torque becomes equal to or less than the target torque. Td is the absolute value of the counter torque (see FIG. 1(B)).

[0068]

number

[0069] Next, the calculation unit 234 obtains a new first correction value for the reference torque based on the correction coefficient determined based on the number of deviations and the amount of change in the driver torque relative to the target torque (step S205), and ends the series of processes. The calculation unit 234 is an example of a correction value calculation unit.

[0070] If no counter torque is generated (step S201-No), or if the vehicle 10 has not deviated from the lane markings of the lane in which the vehicle 10 is traveling (step S202-No), the series of processes ends.

[0071] Next, the process in which the calculation unit 234 determines a new first correction value will be described below with reference to Fig. 5. The calculation unit 234 determines, as a new first correction value, the product of a correction coefficient determined based on the number of departures and the product S of the amount of change in the driver torque with respect to the reference torque.

[0072] FIG. 5 is a diagram for explaining an example of the relationship between the correction coefficient and the number of departures. The relationship between the correction coefficient and the number of departures has a first region where the correction coefficient increases with an increase in the number of departures, a second region where the correction coefficient increases with an increase in the number of departures more than in the first region, and a third region where the correction coefficient increases with an increase in the number of departures less than in the second region. In the process of learning the first correction value, the steering of the steering wheel by the driver may be accidental in the early stages of learning, so the correction coefficient is made small (first region). Then, when there is a tendency in the steering of the steering wheel by the driver, the correction coefficient is made large (second region). However, a substantial upper limit is set for the correction coefficient (third region). For example, a sigmoid function can be used as the correction coefficient. In this embodiment, the correction coefficient has a positive value.

[0073] The product M1 (first correction value) of the correction coefficient and the change amount S of the driver torque is calculated by the following formula (4). Here, i is the number of deviations, and α i is the correction factor for the i-th deviation, and S i is the amount of change in driver torque at the i-th deviation. The initial value α0 of the correction coefficient may be set to zero.

[0074]

number

[0075] The correction coefficient is zero or a positive value. The amount of change in the driver torque is zero or a positive value. Therefore, the first correction value M1 is also zero or a positive value. It is preferable to set an upper limit for the first correction value M1. This upper limit can be determined, for example, experimentally or empirically.

[0076] Next, the second correction value calculation process will be described below with reference to Fig. 6. Fig. 6 is an example of an operation flowchart related to the second correction value calculation process of the torque control device 17 of this embodiment. The torque control device 17 calculates the second correction value based on the distance traveled by the vehicle 10 in a state in which the driver torque exceeds the target torque and the number of departures is not counted. Specifically, the torque control device 17 executes the second correction value calculation process in accordance with the operation flowchart shown in Fig. 6 each time it is determined that the driver torque has been generated and then that the driver torque has disappeared.

[0077] The processes in steps S301 and S302 are similar to the processes in steps S201 and S202 described above.

[0078] If the vehicle 10 has not deviated from the lane markings of the lane in which the vehicle 10 is traveling (step S302-No), the counting unit 233 counts the number of non-departure times in which the vehicle 10 has not deviated from the lane markings of the lane in which the vehicle 10 is traveling (step S303). The initial value of the non-departure number is zero.

[0079] Next, the calculation unit 234 calculates the non-departure traveling distance traveled by the vehicle 10 in a state in which the driver torque exceeds the target torque and the number of departures is not counted (step S304). The calculation unit 234 calculates the non-departure traveling distance traveled by the vehicle 10 between the start time when the driver torque reaches the target torque and the end time when the driver torque becomes equal to or less than the target torque.

[0080] The calculation unit 234 calculates a new second correction value for the reference torque based on the correction coefficient determined based on the non-departure count and the non-departure traveling distance (step S205), and ends the series of processes. The above description of the process for calculating the first correction value is appropriately applied to the process for calculating the second correction value.

[0081] If no counter torque is generated (step S301-No), or if the vehicle 10 deviates from the lane markings of the lane in which the vehicle 10 is traveling (step S302-Yes), the series of processes ends.

[0082] Next, the process of calculating a new second correction value by the calculation unit 234 will be described below. The calculation unit 234 calculates the new second correction value by multiplying a correction coefficient determined based on the non-departure count by the non-departure mileage. The initial value of the correction coefficient may be set to zero.

[0083] The relationship between the correction coefficient and the non-departure count is the same as that between the correction coefficient and the deviation count shown in FIG. 5. The relationship between the correction coefficient and the non-departure count has a first region where the correction coefficient increases with an increase in the non-departure count, a second region where the correction coefficient increases with an increase in the non-departure count more than in the first region, and a third region where the correction coefficient increases with an increase in the non-departure count less than in the second region. In the process of learning the second correction value, the steering of the steering wheel by the driver may be accidental in the early stages, so the correction coefficient is made small (first region). Then, when there is a tendency in the steering of the steering wheel by the driver, the correction coefficient is made large (second region). However, a substantial upper limit is set for the correction coefficient (third region). For example, a sigmoid function can be used as the correction coefficient. In this embodiment, the correction coefficient has a positive value.

[0084] Here, the correction coefficient for determining the second correction value is zero or a positive value. The non-departure mileage is a positive value. Therefore, the second correction value M2 is also zero or a positive value. It is preferable to set an upper limit for the second correction value M2. This upper limit can be determined, for example, experimentally or empirically.

[0085] 7 is a diagram showing an example of the relationship between the correction value and the travel distance. Here, the correction value represents a value obtained by subtracting the second correction value from the first correction value. When the counter torque becomes large when the steering wheel is turned, the driver applies a rotational force to counter the counter torque in order to steer the steering wheel, thereby applying a driver torque to the steering wheel.

[0086] Therefore, even if the driver is steering the steering wheel unconsciously, the driver becomes aware that he or she is steering. Then, by sensing the counter torque, the driver reduces the steering amount of the steering wheel. Therefore, it is considered that the second correction value changes to increase with the mileage.

[0087] Furthermore, when the vehicle 10 deviates from a lane marking, the control unit 231 notifies the driver that the vehicle 10 has deviated from the lane marking via the UI 5. At this time, the control unit 231 may request that the driving of the vehicle 10 be transferred from automatic control to the driver.

[0088] Due to the increase in the counter torque and notification that the vehicle has deviated from the lane marking, the driver will operate the steering wheel less in a way that would cause the vehicle 10 to deviate from the lane marking, and the correction value is likely to converge to a value that reflects the driver's preference.

[0089] As described above, the torque control device of this embodiment determines the standard for starting to apply a counter torque to the steering wheel according to the driver's past steering wheel operations, and therefore can suppress deviation from the lane markings of the lane in which the vehicle is traveling according to the individual steering characteristics of each driver. For example, if the threshold for generating a counter torque according to the driver's past steering wheel operations is set low, a counter torque is generated even if the driver moves the steering wheel lightly, so that the driver can be aware that he or she is steering. As a result, the torque control device of this embodiment can suppress deviation from the lane markings of the lane without the driver unconsciously performing a steering operation.

[0090] In the present disclosure, the vehicle control device, the computer program for controlling a vehicle, and the vehicle control method of the above-mentioned embodiments can be appropriately modified without departing from the spirit of the present disclosure. Furthermore, the technical scope of the present disclosure is not limited to those embodiments, but extends to the inventions described in the claims and their equivalents.

[0091] For example, when the vehicle is located in bad weather such as rain or snow, the correction coefficient may be set to zero or may be smaller than when the vehicle is in good weather such as sunny weather. In bad weather, the road surface is wet, so the driving conditions of the vehicle are different from when the road surface is dry. This can reduce the effect of the correction in bad weather on the correction value in good weather. Also, the correction value may be calculated separately for good weather and bad weather. [Explanation of symbols]

[0092] 1 Vehicle Control System 2 Camera 3 Positioning information receiver 4. Navigation devices 5 User Interface 5a Display device 6. Torque detector 10 Vehicles 11 Map information storage device 12 Position estimation device 13 Object detection device 14 Traffic lane planning device 15 Operation planning device 16 Vehicle control device 17 Torque control device 21 Communication Interface 22 Memory 23 Processors 231 Control Unit 232 Decision Section 233 Counting Department 234 Calculation Section 18 In-vehicle network

Claims

1. A vehicle control device for controlling an automatically controlled vehicle, a target torque determination unit that determines a target torque that is a target of the driver torque that starts to generate a counter torque to a driver torque generated by an operation of the steering wheel by a driver during automatic control operation, based on a reference torque that is a reference for the driver torque and a current correction value for the reference torque; a counting unit that counts the number of times the vehicle deviates from a lane marking of the lane on which the vehicle is traveling in a state in which the driver torque exceeds the target torque; a correction value calculation unit that calculates a new correction value for the reference torque based on a correction coefficient that is determined based on the number of deviations; having The vehicle control device, wherein the target torque determination unit determines the next target torque based on the reference torque and a new correction value for the reference torque.

2. a change amount calculation unit that calculates a change amount of the driver torque with respect to the target torque, The vehicle control device according to claim 1 , wherein the correction value calculation unit determines a new correction value for the reference torque based on the correction coefficient and an amount of change in the driver torque.

3. The correction value calculation unit calculates a second correction value based on a distance traveled by the vehicle in a state in which the driver torque exceeds the target torque and the number of departures is not counted, The vehicle control device according to claim 1 , wherein the correction value calculation unit determines a correction value for the reference torque based on the correction value and the second correction value.

4. 4. The vehicle control device according to claim 1, wherein the relationship between the correction coefficient and the number of departures has a first region in which the correction coefficient increases as the number of departures increases, a second region in which the correction coefficient increases as the number of departures increases more than in the first region, and a third region in which the correction coefficient increases as the number of departures increases more than in the second region.

5. A vehicle control computer program for controlling an automatically controlled vehicle, comprising: determining a target torque that is a target of the driver torque at which a counter torque is to be generated on the steering wheel, based on a reference torque that is a reference for a driver torque at which a counter torque is to be generated against a driver torque generated by an operation of the steering wheel by a driver during automatic control operation, and a current correction value for the reference torque; Counting the number of times the vehicle deviates from a lane marking in the lane in which the vehicle is traveling while the driver torque exceeds the target torque; a processor is caused to execute a process including determining a new correction value for the reference torque based on a correction coefficient determined based on the number of deviations; a next target torque is determined based on the reference torque and a new correction value for the reference torque.

6. A vehicle control method for controlling an automatically controlled vehicle, comprising: determining a target torque that is a target of the driver torque at which a counter torque is to be generated on the steering wheel, based on a reference torque that is a reference for a driver torque at which a counter torque is to be generated against a driver torque generated by an operation of the steering wheel by a driver during automatic control operation, and a current correction value for the reference torque; Counting the number of times the vehicle deviates from a lane marking in the lane in which the vehicle is traveling while the driver torque exceeds the target torque; determining a new correction value for the reference torque based on a correction coefficient determined based on the number of deviations; Including The vehicle control method according to claim 1, wherein the next target torque is determined based on the reference torque and a new correction value for the reference torque.

Images