Vehicle control device, storage medium and vehicle control method

Abstract

A vehicle control device, a storage medium, and a vehicle control method are provided, which can suppress a vehicle from deviating from a lane marking line of a driving lane. The vehicle control device includes: a target torque determination unit (232) for determining a target driver torque for starting to generate a counter torque on the steering wheel based on a reference torque for starting to generate a counter torque to a driver torque generated by a driver's steering wheel operation and a current correction value for the reference torque; a counting unit (233) for counting the number of times the vehicle deviates from a lane marking line of a driving lane when the driver torque exceeds the target torque; and a correction value calculation unit (234) for calculating a new correction value for the reference torque based on a correction coefficient determined based on the number of deviations. The target torque determination unit (232) determines the next target torque based on the reference torque and the new correction value for the reference torque.

Description

Technical Field

[0001] This disclosure relates to a vehicle control device, a storage medium for storing a computer program for vehicle control, and a vehicle control method. Background Art

[0002] The vehicle's automated control system generates a navigation route based on the vehicle's current location, destination location, and navigation map. The system uses map information to estimate the vehicle's current location and controls the vehicle to follow the navigation route.

[0003] When the driver operates the steering wheel during automatic driving, the automatic control system detects the rotational force that causes the steering wheel to rotate, i.e., the driver torque. Based on the driver torque, it generates a reverse torque that causes the steering wheel to rotate in the opposite direction to the driver's operation.

[0004] The automatic control system begins to apply counter-torque to the steering wheel when it detects a driver torque that is above the reference torque, which serves as the initial reference for generating counter-torque on the steering wheel. Since the counter-torque also increases as the driver torque increases, the driver is aware of the magnitude of the driver torque they are using to operate the steering wheel.

[0005] In this way, the automatic control system allows the driver to perform steering operations while making the driver aware that the automatic control system is in control of the steering.

[0006] Patent document 1 proposes a vehicle operation reaction force control device that further reduces driving burden by controlling the reaction force of the vehicle's operating mechanisms, such as the steering wheel, in accordance with the individual differences of each driver.

[0007] Existing technical documents

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2008-296605 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] However, even if the magnitude of the counter-torque is varied to match the force applied by each driver while steering, if the reference point for starting to apply the counter-torque to the steering wheel is inappropriate, the driver may sometimes be delayed in realizing that they are steering. As a result, it is possible for the steering wheel to be unconsciously steered by the driver, causing the vehicle to deviate from the lane markings of the driving lane.

[0012] Therefore, the purpose of this disclosure is to provide a vehicle control device that can suppress a vehicle from deviating from lane markings in a way that is tailored to each driver.

[0013] Technical solutions for solving the problem

[0014] According to one embodiment, a vehicle control device is provided. This vehicle control device includes: a target torque determination unit that determines a target torque based on a reference torque and a current correction value for the reference torque, the reference torque being a torque that serves as a reference for a driver torque that begins to generate a reverse torque against the driver torque, the driver torque being a torque generated by the driver's steering wheel operation, and the target torque being a target torque that serves as a target for the driver torque that begins to generate a reverse torque on the steering wheel; a counting unit that counts the number of times the vehicle has left the lane markings while 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 determined based on the number of departures; the target torque determination unit then determines the next target torque based on the reference torque and the new correction value for the reference torque.

[0015] Furthermore, in this vehicle control device, it is preferable to have a change calculation unit that calculates the change in driver torque relative to target torque, and a correction value calculation unit that calculates a new correction value for reference torque based on a correction coefficient and the change in driver torque.

[0016] Furthermore, 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 when the driver torque exceeds the target torque and the number of disengagements is not counted, and the target torque determination unit determines the next target torque based on the reference torque, the new correction value for the reference torque, and the second correction value.

[0017] Furthermore, in this vehicle control device, it is preferable that the relationship between the correction coefficient and the number of disengagements has the following characteristics: a first region in which the correction coefficient increases with the number of disengagements, a second region in which the correction coefficient increases significantly with the number of disengagements compared to the first region, and a third region in which the correction coefficient increases slightly with the number of disengagements compared to the second region.

[0018] According to another embodiment, a non-transient storage medium is provided that stores a vehicle control computer program. The vehicle control computer program causes a processor to execute a process comprising: determining a target torque based on a reference torque and a current correction value for the reference torque, the reference torque being a torque that serves as a reference for a driver torque that begins to generate a reverse torque against the driver torque, the driver torque being a torque generated by the driver's steering wheel operation; the target torque being a torque that serves as a target for a driver torque that begins to generate a reverse torque against the steering wheel; counting the number of times the vehicle has left the driving lane markings while the driver torque exceeds the target torque; and calculating a new correction value for the reference torque based on a correction coefficient determined based on the number of departures, the next target torque being determined based on the reference torque and the new correction value for the reference torque.

[0019] According to another embodiment, a vehicle control method is provided. This vehicle control method, executed by a vehicle control device, includes: determining a target torque based on a reference torque and a current correction value for the reference torque, wherein the reference torque is a torque that serves as a reference for a driver torque that begins to generate a reverse torque against a driver torque, the driver torque being a torque generated by the driver's steering wheel operation; the target torque being a torque that serves as a target for the driver torque that begins to generate a reverse torque on the steering wheel; counting the number of times the vehicle has left the lane markings while the driver torque exceeds the target torque; and calculating a new correction value for the reference torque based on a correction coefficient determined based on the number of departures, wherein the next target torque is determined based on the reference torque and the new correction value for the reference torque.

[0020] Invention Effects

[0021] The vehicle control device disclosed herein determines the timing of generating reverse torque based on the driver's past steering wheel operations, thereby making the driver aware that they are steering, and thus can match each driver to prevent the vehicle from deviating from the lane markings. Attached Figure Description

[0022] Figure 1 (A) is a diagram illustrating the operation of the torque control device of this embodiment, showing the vehicle traveling on the road.

[0023] Figure 1 (B) is a diagram that summarizes the operation of the torque control device of this embodiment and illustrates the relationship between the driver torque and the target torque.

[0024] Figure 1(C) is a diagram illustrating the operation of the torque control device of this embodiment and explaining the new target torque.

[0025] Figure 2 This is a schematic diagram of the vehicle configuration of the vehicle control system implemented in this embodiment.

[0026] Figure 3 This is an example of an operation flowchart related to the target torque determination process of the torque control device in this embodiment.

[0027] Figure 4 This is an example of an operation flowchart related to the calculation of the first correction value of the torque control device in this embodiment.

[0028] Figure 5 This is a graph illustrating an example of the relationship between the correction factor and the number of escapes.

[0029] Figure 6 This is an example of an operation flowchart related to the calculation of the second correction value of the torque control device in this embodiment.

[0030] Figure 7 This is a graph illustrating an example of the relationship between the correction value and the driving distance.

[0031] Explanation of reference numerals in the attached figures

[0032] 1 Vehicle Control System

[0033] 2 cameras

[0034] 3-position information receiver

[0035] 4 navigation devices

[0036] 5 User Interface

[0037] 5a display device

[0038] 6 Torque Detection Device

[0039] 10 vehicles

[0040] 11 Map information storage devices

[0041] 12-position estimation device

[0042] 13 Object Detection Device

[0043] 14-lane planning device

[0044] 15 Driving Plan Device

[0045] 16 Vehicle control devices

[0046] 17 Torque Control Device

[0047] 21 communication interfaces

[0048] 22 memory

[0049] 23 processor

[0050] 231 Control Department

[0051] 232 Decision Department

[0052] 233 Counting Unit

[0053] 234 Calculation Department

[0054] 18 In-vehicle network Detailed Implementation

[0055] Figure 1 (A) Figure 1 (C) is a diagram illustrating the general operation of the torque control device according to this embodiment. Figure 1 (A) is a diagram showing a vehicle traveling on a road. Figure 1 (B) is a graph illustrating the relationship between driver torque and target torque. Figure 1 (C) is a diagram illustrating the new target torque.

[0056] The following is a reference. Figure 1 (A) Figure 1 (C) will describe the general outline of the actions of the driving plan device 15 related to vehicle control processing disclosed in this specification.

[0057] like Figure 1 As shown in (A), vehicle 10 travels on lane 51 of road 50, which has lanes 51 and 52. Lanes 51 and 52 are separated by lane markings 53.

[0058] The automatically controlled vehicle 10 has a user interface (UI) 5 and a torque control device 17. When the driver operates the steering wheel (not shown), the torque control device 17 detects the rotational force that causes the steering wheel to rotate, i.e., the driver torque. Based on the driver torque, the torque control device 17 generates a rotational force on the steering wheel that causes it to rotate in the opposite direction to the driver's operation, i.e., a counter-torque.

[0059] like Figure 1 As shown in (A), although the driver only intended to put his hands on the steering wheel, the steering wheel was operated by the driver and the vehicle 10 left the lane marking 52 of the lane 51 it was traveling in.

[0060] Figure 1 (B) shows Figure 1(A) shows the time-varying variation of the driver torque of vehicle 10. The vertical axis represents the absolute value of the torque. Since the value of the driver torque, which serves as the reference for starting to apply counter-torque to the steering wheel, is large, the time point at which counter-torque is applied to the steering wheel is delayed. Therefore, even though the counter-torque increases as the driver torque increases, the time point at which the driver becomes aware that he is steering is also delayed.

[0061] When the torque control device 17 detects driver torque, it determines a target torque, based on a reference torque and a current correction value for the reference torque, as the target torque for which reverse torque is generated at the steering wheel. Here, the reference torque is the magnitude of the torque that serves as a reference for the driver torque that begins to generate reverse torque at the steering wheel. When the torque control device 17 detects driver torque exceeding the target torque at the steering wheel, it begins to apply reverse torque to the steering wheel. Figure 1 As shown in (B), the rotation of the steering wheel of vehicle 10 is generated by the difference between the driver's torque and the reverse torque, i.e., the actual torque.

[0062] The torque control device 17 begins to generate a counter-torque on the steering wheel when the driver's torque reaches the target torque. This counter-torque causes the steering wheel to rotate in the opposite direction to the rotation caused by the driver's torque. The torque control device 17 controls the magnitude of the counter-torque based on the magnitude of the driver's torque generated on the steering wheel.

[0063] However, due to the time delay in the generation of the reverse torque, the steering wheel is operated by the driver, and the vehicle 10 is steered to the right. As a result, the vehicle 10 leaves the lane markings 52.

[0064] The torque control device 17 notifies the driver via UI5 that the vehicle 10 has left the lane markings 52. Additionally, the torque control device 17 can also, while notifying the vehicle 10 that it has left the lane markings 52, simultaneously request the driver to transfer control of the vehicle 10 from automatic control.

[0065] The driver, notified that vehicle 10 has left lane marking 52, applies driver torque to the steering wheel to steer vehicle 10 to the left. The direction of the driver torque is opposite to that when steer vehicle 10 to the right. Torque control device 17 continuously applies counter-torque to the steering wheel based on the driver torque.

[0066] As vehicle 10 moves toward the center of lane 51, the driver torque applied to the steering wheel by the driver decreases. Furthermore, as the driver torque decreases, the counter-torque also decreases. Since vehicle 10 has returned to the center of lane 51, the driver stops steering. Because the driver torque disappears, the torque control device 17 stops applying counter-torque to the steering wheel.

[0067] The torque control device 17 counts the number of times the vehicle 10 leaves the lane marking 53 of the driving lane 51 when 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 by the number of departures.

[0068] like Figure 1 As shown in (C), when the torque control device 17 detects the driver torque, it determines the next target torque based on the reference torque and a new correction value for the reference torque. The next target torque is lower than the previous value, changing in a way that generates reverse torque at an earlier point in time. Thus, the driver can consciously control the steering wheel at an earlier point in time.

[0069] As explained above, by determining the reference point for applying counter-torque to the steering wheel based on the driver's past steering wheel operations, the driver is aware that they are steering, thus enabling the vehicle 10 to be prevented from deviating from the lane markings in a way that matches each driver.

[0070] Figure 2 This is a schematic diagram of the vehicle 10 of the vehicle control system 1 implemented in this embodiment. 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 lane planning device 14, a driving planning device 15, a vehicle control device 16, and a torque control device 17. Furthermore, the vehicle 10 may also include a ranging sensor (not shown) such as millimeter-wave radar for determining the distance to objects around the vehicle 10.

[0071] 2. Camera, 3. Position information receiver, 4. Navigation device, 5. UI, 6. Torque detection device, 11. Map information storage device, 12. Position estimation device, 13. Object detection device, 14. Lane planning device, 15. Driving planning device, 16. Vehicle control device, and 17. Torque control device are connected in a communicative manner via an in-vehicle network 18 based on a standard such as a controller area network.

[0072] Camera 2 is an example of an imaging unit installed in vehicle 10. Camera 2 is mounted on vehicle 10 facing forward. Camera 2, for example, captures camera images of the environment representing a predetermined area in front of vehicle 10 at predetermined intervals. The camera images may show road features, such as lane markings, within the predetermined area in front of vehicle 10. Camera 2 has a 2D detector, such as a CCD or C-MOS, composed of an array of photoelectric conversion elements sensitive to visible light, and an imaging optical system that images the area to be photographed onto this 2D detector.

[0073] Whenever camera 2 captures an image, it outputs the image and the time of capture via the in-vehicle network 18 to the position estimation device 12 and the object detection device 13. The camera image is used in the position estimation device 12 to estimate the position of vehicle 10. Additionally, the camera image is used in the object detection device 13 to detect other objects around vehicle 10.

[0074] The positioning information receiver 3 outputs positioning information indicating the current position of the vehicle 10. For example, the positioning information receiver 3 can be configured as a GNSS receiver. Whenever the positioning information is acquired at a predetermined reception period, the positioning information receiver 3 outputs the positioning information and the time of acquisition of the positioning information to the navigation device 4 and the map information storage device 11, etc.

[0075] The navigation device 4 generates a navigation route from the current position of the vehicle 10 to the destination position based on navigation map information, the destination position of the vehicle 10 input from the UI5, and the positioning information receiver 3 indicating the current position of the vehicle 10. The navigation route includes information related to right turns, left turns, merging, branching, etc. The navigation device 4 regenerates the navigation route for the vehicle 10 if a new destination position is set or if the current position of the vehicle 10 deviates from the navigation route. Whenever a navigation route is generated, the navigation device 4 outputs the navigation route to the position estimation device 12 and the driving lane planning device 14 via the in-vehicle network 18.

[0076] UI5 is an example of a notification unit. UI5 is controlled by navigation device 4, driving plan device 15, vehicle control device 16, and torque control device 17, and notifies the driver of driving information of vehicle 10. The driving information of vehicle 10 includes information related to the vehicle's current position, navigation route, and other information related to the vehicle's current and future paths. Additionally, UI5 can notify the driver of information indicating that vehicle 10 has left lane markings and requests to transfer driving control from the automatic control system to the driver. UI5 has a display device 5a, such as an LCD or touch panel, for displaying driving information. UI5 may also have an audio output device (not shown) for notifying the driver of driving information. Furthermore, UI5 generates operation signals corresponding to the driver's actions on vehicle 10. Operation information may include, for example, destination location, route, vehicle speed, and other control information. As an input device for inputting operation information from the driver to vehicle 10, UI5 may have, for example, a touch panel or operation buttons. UI5 outputs the input operation information to the navigation device 4, driving plan device 15 and vehicle control device 16 via the in-vehicle network 18.

[0077] The torque detection device 6 detects the force generated by the driver's operation of the steering wheel, which causes the steering wheel's rotation axis to rotate, and outputs a signal indicating the force causing the rotation to the torque control device 17, etc. The torque detection device 6 can also detect the angle and angular velocity of the steering wheel's rotation axis.

[0078] The map information storage device 11 stores wide-area map information covering a relatively broad range (e.g., a radius of 10 to 30 km) including the current location of the vehicle 10. This map information includes high-precision map information such as 3D road surface information, and information representing road features and structures such as speed limits, road curvature, lane markings, etc. The positions of lane markings, etc., in the map information are represented, for example, in a world coordinate system with an origin at a predetermined location.

[0079] The map information storage device 11 receives wide-area map information from an external server via a base station and stores it in the storage device based on the current location of the vehicle 10 through wireless communication via a wireless communication device (not shown) mounted on the vehicle 10. Whenever 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 containing a relatively narrow area (e.g., a radius of 100m to 10km) of the current location indicated by the positioning information to the location estimation device 12, object detection device 13, driving lane planning device 14, driving planning device 15, and vehicle control device 16 via the in-vehicle network 18.

[0080] The position estimation device 12 estimates the position of the vehicle 10 at the time the camera image was captured, based on the road features surrounding the vehicle 10 shown in the camera image captured by the camera 2. For example, the position estimation device 12 compares the lane markings identified in the camera image with the lane markings shown in the map information input from the map information storage device 11 to determine the estimated position and estimated azimuth of the vehicle 10 at the time the camera image was captured. In addition, the position estimation device 12 estimates the driving lane of 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 of the vehicle 10. Whenever the position estimation device 12 determines the estimated position, estimated azimuth, and driving lane of the vehicle 10 at the time the camera image was captured, it outputs this information to the object detection device 13, the driving lane planning device 14, the driving planning device 15, and the vehicle control device 16. Whenever the position estimation device 12 calculates the estimated position, estimated azimuth angle and driving lane of the vehicle 10 at the time the camera image is captured, it outputs the position of the vehicle 10 and the position of the lane marking line represented by the map information to the torque control device 17.

[0081] The object detection device 13 detects other objects and their types (e.g., vehicles) around the vehicle 10 based on camera images. Other objects include other vehicles traveling around the vehicle 10. The object detection device 13 tracks the detected other objects and calculates their trajectories. Based on lane markings and the positions of other objects represented by map information, the object detection device 13 determines the driving lane in which the other objects are traveling. Furthermore, the object detection device 13 outputs object detection information, including information indicating the type of detected other objects, information indicating their positions, and information indicating the driving lane, to the driving lane planning device 14 and the driving planning device 15, etc.

[0082] The lane planning device 14 generates a lane plan at predetermined intervals, within the nearest driving range (e.g., 10 km) selected from the navigation route, based on map information, the navigation route, surrounding environment information, and the current position of the vehicle 10. It then selects a lane within the road where the vehicle 10 will travel and generates a lane plan representing the predetermined lane the vehicle 10 will travel in. The lane planning device 14 generates the lane plan, for example, in a manner that causes the vehicle 10 to travel in a lane other than the overtaking lane. Whenever a lane plan is generated, the lane planning device 14 outputs it to the driving planning device 15.

[0083] The driving plan device 15 performs driving plan processing, that is, at a driving plan generation time set at a predetermined period, it generates a driving plan representing the predetermined driving trajectory of the vehicle 10 up to a predetermined time (e.g., 5 seconds) based on the driving lane plan, map information, the current position of the vehicle 10, surrounding environment information, and vehicle status information. The surrounding environment information includes the positions and speeds of other vehicles traveling around the vehicle 10. The vehicle status information includes the current position, speed, acceleration, and direction of travel of the vehicle 10. The driving plan is represented as a set of the target positions of the vehicle 10 and the speeds of target vehicles at those target positions at each time point from the current time to the predetermined time. The driving plan generation period is preferably shorter than the driving lane plan generation period. The driving plan device 15 generates the driving plan at an interval that maintains a predetermined distance or more between the vehicle 10 and other objects (vehicles, etc.).

[0084] The vehicle control unit 16 controls various parts of the vehicle 10 based on the vehicle 10's current position, speed, yaw rate, and the driving plan generated by the driving plan unit 15. For example, the vehicle control unit 16 calculates the vehicle 10's steering angle, acceleration, and angular acceleration according to the driving plan, speed, and yaw rate, and sets the steering input, accelerator opening, or braking input in a manner consistent with these steering angle, acceleration, and angular acceleration. Then, the vehicle control unit 16 outputs a control signal corresponding to the set steering input to an actuator (not shown) that controls the steering wheel of the vehicle 10 via the in-vehicle network 18. Additionally, the vehicle control unit 16 outputs a control signal corresponding to the set accelerator opening to the vehicle 10's drive unit (engine or motor) via the in-vehicle network 18. Alternatively, the vehicle control unit 16 outputs a control signal corresponding to the set braking input to the vehicle 10's brakes (not shown) via the in-vehicle network 18.

[0085] The torque control unit 17 performs control processing, decision processing, counting processing, and calculation processing. For this purpose, the driving planning unit 15 has a communication interface (IF) 21, a memory 22, and a processor 23. The communication interface 21, memory 22, and processor 23 are connected via signal lines 24. The communication interface 21 has interface circuitry for connecting the torque control unit 17 to the vehicle network 18. The torque control unit 17 is an example of a vehicle control device.

[0086] Memory 22 is an example of a storage unit, such as a volatile semiconductor memory or a non-volatile semiconductor memory. Furthermore, memory 22 stores computer programs and various data used in information processing executed by processor 23.

[0087] The torque control device 17 has all or part of its functions, for example, implemented by a computer program operating on the processor 23. The processor 23 has a control unit 231, a decision 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 on the processor 23. The processor 23 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 23 may also have other arithmetic circuits such as logic operation units, numerical operation units, or graphics processing units.

[0088] The control unit 231 detects the driver torque based on a signal input from the torque detection device 6, which represents the force required to rotate the steering wheel. For example... Figure 1As shown in (B), when the control unit 231 detects a driver torque exceeding the target torque, it controls the drive unit (not shown) that rotates the steering wheel's rotation axis to apply a reverse torque to the steering wheel based on the magnitude of the driver torque. This drive unit, controlled by the control unit 231, applies the reverse torque to the steering wheel's rotation axis. The control unit 231 may also determine the reverse torque based on the driver torque and the angle or angular velocity of the steering wheel's rotation axis. The direction of the reverse torque is opposite to the driver torque. Other operations of the torque control device 17, including the process of determining the target torque, will be described later.

[0089] Map information storage device 11, location estimation device 12, object detection device 13, driving lane planning device 14, driving planning device 15, vehicle control device 16, torque control device 17, for example, an electronic control unit (ECU). Figure 2 In this document, the map information storage device 11, the location 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 described as separate devices, but all or part of these devices may also constitute a single device.

[0090] Figure 3 This is an example of an operation flowchart related to the target torque determination process of the torque control device 17 in this embodiment. Hereinafter, with reference to... Figure 3 The target torque determination process of the torque control device 17 will be explained below. At the target torque determination time with a predetermined period, the torque control device 17... Figure 3 The flowchart shown illustrates the execution of the target torque determination process. The predetermined period can be set, for example, to 0.05–0.1 milliseconds.

[0091] First, the determination unit 232 determines whether driver torque has been generated (step S101). The determination unit 232 detects driver torque based on a signal representing the force that rotates the steering wheel, which is input from the torque detection device 6. If driver torque exceeding a predetermined threshold torque is generated during a period of time longer than a predetermined reference time, the determination unit 232 determines that driver torque has been generated. The threshold torque is preferably determined to be a magnitude that is not affected by noise that may be included in the signal input from the torque detection device 6.

[0092] When a 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), ending a series of processes. The magnitude of the reference torque serves as a reference for generating a reverse torque in the steering wheel based on the driver torque generated in the steering wheel according to the driver's steering wheel operation. The magnitude of the reference torque is preferably set to be such that it can detect steering wheel operation based on the driver's intention.

[0093] The magnitude of the target torque becomes the target for the driver torque that begins to generate reverse torque in the steering wheel. The correction value includes a first correction value M1 determined based on the number of times the vehicle has deviated from the lane markings. 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.

[0094] The determination unit 232 calculates the target torque Tb by subtracting the current first correction value M1, which is determined based on the number of disengagements, from the reference torque Ta as shown in the following formula (1).

[0095] Tb=Ta-M1 (1) Alternatively, the determination unit 232 can also calculate the value obtained by subtracting the current second correction value M2, which is determined based on the distance traveled by the vehicle 10 without counting the number of disengagements, from the current first correction value M1, as the correction value for the reference torque. In this case, the determination unit 232 calculates the 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 equation (2) below, as the target torque Tb. The process of calculating the first correction value M1 and the second correction value M2 will be described later.

[0096] Tb=Ta-M1+M2 (2)

[0097] On the other hand, if no driver torque is generated (step S101 - No), the series of processes ends.

[0098] If the decision unit 232 determines that a driver torque has been generated and thus determines a target torque, it preferably does not start a new target torque determination process until it determines that the driver torque has disappeared. If the decision unit 232 does not generate a driver torque of a predetermined threshold torque or higher during a period longer than a predetermined reference time, it determines that the driver torque has disappeared.

[0099] Then, while referring to Figure 4 The process for calculating the first correction value will be explained below. Figure 4This is an example of an operation flowchart related to the calculation of the first correction value of the torque control device 17 in this embodiment. Whenever the driver torque disappears after it has been determined that driver torque has been generated, the torque control device 17 proceeds according to... Figure 4 The illustrated operation flowchart performs the first correction value calculation process. Furthermore, if the torque control device 17 does not generate a driver torque exceeding a predetermined threshold torque for a period exceeding a predetermined reference time, it determines that the driver torque has disappeared.

[0100] First, the counting unit 233 determines whether a reverse torque was generated during the driver's steering (step S201). Even if a driver torque is generated, a reverse torque will not be generated if the magnitude of the driver torque is less than the target torque.

[0101] When a reverse torque is generated (step S201 - Yes), the counting unit 233 determines whether the vehicle 10 has deviated from the lane markings of the driving lane while the driver torque exceeds the target torque (step S202). Based on the position of the vehicle 10, the counting unit 233 calculates the positions of the right and left ends of the vehicle 10. The positions of the right and left ends of the vehicle 10 are represented, for example, in a world coordinate system. Furthermore, the counting unit 233 compares the positions of the right and left ends of the vehicle 10 with the positions of the lane markings located on both sides of the vehicle 10's current position. Then, if the driver torque exceeds the target torque, the right end of the vehicle 10 exceeds the lane markings, or the left end of the vehicle 10 exceeds the lane markings, the counting unit 233 determines whether the vehicle 10 has deviated from the lane markings of the driving lane. When the driver torque exceeds the target torque, a reverse torque is generated.

[0102] When vehicle 10 leaves the lane markings of its driving lane (step S202 - Yes), the counting unit 233 counts the number of times vehicle 10 has left the lane markings of its driving lane (step S203). The initial value of the number of departures is zero.

[0103] Next, the calculation unit 234 calculates the change in driver torque relative to the target torque each time the number of disengagements is counted (step S204). The calculation unit 234 is an example of a change calculation unit. The calculation unit 234 calculates the change in driver torque relative to the target torque using the following formula (3) during the period from when driver torque is determined to have been generated until when driver torque is determined to have disappeared. Here, the start time t1 is the time when driver torque reaches the target torque, and the end time t2 is the time when driver torque becomes below the target torque. Td is the reverse torque (refer to...). Figure 1 The absolute value of (B)).

[0104]

[0105] Next, the calculation unit 234 calculates a new first correction value for the reference torque based on the correction coefficient determined by the number of disengagements and the change in driver torque relative to the target torque (step S205), thus ending the series of processes. The calculation unit 234 is an example of a correction value calculation unit.

[0106] In addition, if no reverse torque is generated (step S201 - No) or if the vehicle 10 does not leave the lane markings of the driving lane (step S202 - No), the series of processes ends.

[0107] Then, while referring to Figure 5 The following describes the process by which the calculation unit 234 calculates a new first correction value. The calculation unit 234 calculates the product of the correction coefficient determined based on the number of disengagements and the change S of the driver torque relative to the reference torque, as the new first correction value.

[0108] Figure 5 This is a diagram illustrating an example of the relationship between the correction coefficient and the number of disengagements. The relationship between the correction coefficient and the number of disengagements is divided into three regions: a first region where the correction coefficient increases with the number of disengagements; a second region where the correction coefficient increases significantly more than in the first region; and a third region where the correction coefficient increases slightly more than in the second region. During the learning process of the first correction value, in the initial learning stage, since there are occasional instances of driver steering, the correction coefficient decreases (first region). Furthermore, when there is a tendency for the driver to steering, the correction coefficient increases (second region). However, a substantial upper limit is set on 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.

[0109] The product M1 (first correction value) of the correction factor and the change in driver torque S is obtained by the following equation (4). Here, i is the number of disengagements, and α i S is the correction coefficient for the i-th escape. i This is the change in driver torque during the i-th disengagement. Furthermore, the initial value of the correction coefficient α0 can also be set to zero.

[0110] M1=αiSi (4)

[0111] The correction factor is zero or a positive value. The change in 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, through experimentation or based on experience.

[0112] Then, while referring to Figure 6 The following section explains the process for calculating the second correction value. Figure 6 This is an example of an operation flowchart related to the calculation of the second correction value of the torque control device 17 in this embodiment. The torque control device 17 calculates the second correction value based on the distance traveled by the vehicle 10 when the driver torque exceeds the target torque and the number of disengagements is not counted. Specifically, whenever the torque control device 17 determines that the driver torque has disappeared after determining that it has been generated, it proceeds according to... Figure 6 The flowchart shown executes the second correction value calculation process.

[0113] The processing of steps S301 and S302 is the same as that of steps S201 and S202 described above.

[0114] If the vehicle 10 does not leave the lane markings of the driving lane (step S302 - No), the counting unit 233 counts the number of times the vehicle 10 does not leave the lane markings of the driving lane (step S303). The initial value of the number of times it does not leave the lane markings is zero.

[0115] Next, the calculation unit 234 calculates the non-disengagement travel distance of the vehicle 10 when the driver torque exceeds the target torque and the number of disengagements is not counted (step S304). The calculation unit 234 calculates the non-disengagement travel distance of the vehicle 10 between the start time when the driver torque reaches the target torque and the end time when the driver torque becomes below the target torque.

[0116] The calculation unit 234 calculates a new second correction value for the reference torque based on the correction coefficient determined by the number of non-disengagements and the non-disengagement driving distance (step S305), 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.

[0117] In addition, if no reverse torque is generated (step S301 - No) or if the vehicle 10 leaves the lane markings of the driving lane (step S302 - Yes), the series of processes ends.

[0118] Next, the process by which the calculation unit 234 calculates the new second correction value will be explained below. The calculation unit 234 calculates the product of the correction coefficient determined based on the number of non-disengagements and the non-disengagement driving distance as the new second correction value. The initial value of the correction coefficient can also be set to zero.

[0119] The relationship between the correction factor and the number of non-detachments, and Figure 5The relationship between the correction coefficient and the number of disengagements is the same. The relationship between the correction coefficient and the number of non-disengagements has three regions: a first region where the correction coefficient increases with the number of non-disengagements; a second region where the correction coefficient increases significantly more than in the first region; and a third region where the correction coefficient increases slightly more than in the second region. During the learning of the second correction value, initially, since there are occasional instances of driver steering, the correction coefficient decreases (first region). Furthermore, when there is a tendency for the driver to steering, the correction coefficient increases (second region). However, a substantial upper limit is set on 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.

[0120] Here, the correction factor for the second correction value is determined to be either zero or positive. The non-departure driving distance is a positive value. Therefore, the second correction value M2 is also either zero or positive. It is preferable to set an upper limit for the second correction value M2. This upper limit can be determined, for example, through experimentation or based on experience.

[0121] Figure 7 This is a diagram illustrating an example of the relationship between the correction value and the driving distance. Here, the correction value represents the value obtained by subtracting the second correction value from the first correction value. When the reverse torque increases when the steering wheel is turned, the driver applies a rotational force to the steering wheel to counteract the reverse torque, thus applying a driver torque to the steering wheel in order to turn the steering wheel.

[0122] Therefore, even if a driver unconsciously steers the wheel, they will be aware that they are steering. Furthermore, by sensing the reverse torque, the driver reduces the amount of steering wheel input. Therefore, it is assumed that the second correction value changes in a manner that increases along with the travel distance.

[0123] Additionally, when vehicle 10 leaves the lane markings, control unit 231 notifies the driver via UI5 that vehicle 10 has left the lane markings. At this time, control unit 231 can also request that driving of vehicle 10 be transferred from automatic control to driver control.

[0124] By notifying the driver of the increase in reverse torque and the departure from the lane markings, the driver's steering wheel operations are reduced when the vehicle 10 leaves the lane markings. Therefore, it is believed that the correction value converges to a value that reflects the driver's preference.

[0125] As explained above, the torque control device of this embodiment determines the reference for applying counter-torque to the steering wheel based on the driver's past steering wheel operations. Therefore, it can suppress the vehicle from deviating from the lane markings based on each driver's individual steering characteristics. For example, if the threshold for generating counter-torque based on the driver's past steering wheel operations is set low, counter-torque will be generated even if the driver makes a slight steering wheel movement, so the driver can be aware that they are steering. Thus, the torque control device of this embodiment can suppress lane departure from the lane markings without the driver's unconscious steering operation.

[0126] In this disclosure, the vehicle control device, vehicle control computer program, and vehicle control method described above can be appropriately modified as long as they do not depart from the spirit of this disclosure. Furthermore, the technical scope of this disclosure is not limited to these embodiments, but extends to the invention described in the claims and its equivalents.

[0127] For example, when the vehicle is in adverse weather conditions such as rain or snow, the correction factor can be made zero or smaller compared to favorable weather conditions such as sunny days. Because the road surface becomes wet in adverse weather, the driving conditions differ from those on dry roads. Therefore, the impact of the correction for adverse weather conditions on the correction value for favorable weather conditions can be reduced. Alternatively, correction values ​​can be calculated separately for favorable and adverse weather conditions.

Claims

1. A vehicle control device, characterized in that, have: The target torque determination unit determines the target torque based on the reference torque and the current correction value for the reference torque. The reference torque is the torque that serves as a reference for the driver torque that begins to generate a reverse torque against the driver torque. The driver torque is the torque generated by the driver's operation of the steering wheel. The target torque is the torque that serves as the target for the driver torque that begins to generate a reverse torque against the steering wheel. The counting unit counts the number of times the vehicle deviates from the lane markings when the driver torque exceeds the target torque; and The correction value calculation unit calculates a new correction value for the reference torque based on a correction coefficient determined according to the number of disengagements. 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. The vehicle control device according to claim 1, characterized in that, The vehicle control device includes a calculation unit that determines the change in the driver torque relative to the target torque. The correction value calculation unit calculates a new correction value for the reference torque based on the correction coefficient and the change in the driver torque.

3. The vehicle control device according to claim 1 or 2, characterized in that, The correction value calculation unit calculates the second correction value based on the distance traveled by the vehicle when the driver torque exceeds the target torque and the number of disengagements is not counted. The target torque determination unit determines the next target torque based on the reference torque, a new correction value for the reference torque, and the second correction value.

4. The vehicle control device according to any one of claims 1 to 3, characterized in that, The relationship between the correction coefficient and the number of detachments includes: a first region where the correction coefficient increases with the number of detachments; a second region where the correction coefficient increases significantly with the number of detachments compared to the first region; and a third region where the correction coefficient increases slightly with the number of detachments compared to the second region.

5. A non-transitory storage medium storing a computer-readable computer program for vehicle control, the computer program for vehicle control causing a processor to perform processing, characterized in that, The process includes: The target torque is determined based on a reference torque and a current correction value for the reference torque, which is the torque that serves as a reference for the driver torque that begins to generate a reverse torque in response to the driver torque, which is the torque generated by the driver's steering wheel operation; the target torque is the torque that serves as the target for the driver torque that begins to generate a reverse torque in response to the steering wheel operation. The number of times the vehicle deviated from the lane markings when the driver torque exceeded the target torque is counted; and Based on the correction factor determined by the number of disengagements, a new correction value for the reference torque is calculated. The next target torque is determined based on the reference torque and a new correction value for the reference torque.

6. A vehicle control method, executed by a vehicle control device, characterized in that, The vehicle control method includes: The target torque is determined based on a reference torque and a current correction value for the reference torque, which is the torque that serves as a reference for the driver torque that begins to generate a reverse torque in response to the driver torque, which is the torque generated by the driver's steering wheel operation; the target torque is the torque that serves as the target for the driver torque that begins to generate a reverse torque in response to the steering wheel operation. The number of times the vehicle deviated from the lane markings when the driver torque exceeded the target torque is counted; and Based on the correction factor determined by the number of disengagements, a new correction value for the reference torque is calculated. The next target torque is determined based on the reference torque and a new correction value for the reference torque.

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