Vehicle control device, storage medium storing computer program for vehicle control, and vehicle control method

Abstract

A vehicle control device, a storage medium, and a vehicle control method are provided. The vehicle control device sets a reference curve speed when a vehicle travels on a curved road, based on a speed of the vehicle and a radius of curvature of the road, determines a target curve speed when the vehicle travels on the curved road, based on the reference curve speed and a current correction value corresponding to the radius of curvature of the road, counts a number of changes in the speed of the vehicle from the target curve speed by an operation of a driver when the vehicle travels on the curved road, obtains a new correction value corresponding to the radius of curvature of the road with respect to the reference curve speed, based on a correction coefficient determined each time the number of changes is counted and a change amount in the speed of the vehicle from the target curve speed by the operation of the driver, and determines a next target curve speed based on the reference curve speed and the new correction value corresponding to the radius of curvature of the road.

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 Technology

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

[0003] In addition, the automatic control system controls the vehicle's speed to ensure that the vehicle travels at a driver-set speed. This driver-set speed is, for example, set by the driver based on the speed limit (or legal speed) of the road on which the vehicle is traveling. When the vehicle is traveling on a curve, the driver applies lateral acceleration.

[0004] When the lateral acceleration of a vehicle increases, the driver may feel uncomfortable. Therefore, the automatic control system sets a reference speed for cornering based on the radius of curvature of the road. By driving at this reference speed when cornering, the automatic control system prevents excessive lateral acceleration. If the driver sets a speed faster than the reference speed, the automatic control system decelerates the vehicle to the reference speed, allowing the vehicle to continue turning.

[0005] For example, Patent Document 1 proposes a driving behavior control device that sets parameters to determine the driving behavior of an autonomous vehicle based on a specific driving condition, detects the occupant's feedback on the driving behavior generated by the parameters, and determines the driving behavior of the autonomous vehicle when it encounters the specific driving condition again or a driving condition similar to the specific driving condition based on the parameters changed according to the feedback.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2020-192824

[0009] The perception of lateral acceleration while a vehicle is in motion varies from driver to driver, and therefore the permissible range for lateral acceleration also varies from driver to driver. Some drivers perceive a slower cornering reference speed set by the automatic control system (a wider permissible range for lateral acceleration), while others perceive a faster cornering reference speed (a narrower permissible range for lateral acceleration).

[0010] There is room for improvement in how drivers can control their speed when driving on a winding road in a way that satisfies them. Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] Therefore, the purpose of this disclosure is to provide a vehicle control device that enables a vehicle to travel on a winding road with a lateral acceleration that satisfies each driver.

[0013] Methods for solving problems

[0014] According to one embodiment, a vehicle control device is provided. The vehicle control device includes: a reference cornering speed setting unit, which sets a reference cornering speed based on the vehicle's speed and the radius of curvature of the road the vehicle travels on, the reference cornering speed serving as a reference for the vehicle's speed when traveling on a curved road; a target cornering speed determining unit, which determines a target cornering speed based on the reference cornering speed and a current correction value corresponding to the radius of curvature of the road, the target cornering speed serving as a target for the vehicle's controlled speed when traveling on a curved road; a counting unit, which counts the number of times the vehicle's speed changes from the target cornering speed due to driver operation while the vehicle is traveling on a curved road; and a correction value calculation unit, which calculates a new correction value corresponding to the radius of curvature of the road relative to the reference cornering speed based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle's speed due to driver operation when the number of changes is counted, and the target cornering speed determining unit determines the next target cornering speed based on the reference cornering speed and the new correction value corresponding to the radius of curvature of the road.

[0015] Furthermore, in this vehicle control device, it is preferable that the correction value calculation unit calculates the sum of the products of each correction coefficient and the change in vehicle speed when the vehicle speed changes from the target curve speed due to the driver's operation, as a new correction value.

[0016] Furthermore, in this vehicle control device, it is preferable that the relationship between the correction coefficient and the number of changes has a first region where the correction coefficient increases with the increase of the number of changes, a second region where the correction coefficient increases more than the first region with the increase of the number of changes, and a third region where the correction coefficient increases less than the second region with the increase of the number of changes.

[0017] Furthermore, in this vehicle control device, it is preferable that, when the correction value calculation unit calculates a new correction value, it corrects the current correction value of the curvature radius of the road before and after the road for which the new correction value is calculated in such a way that the difference between the current correction value and the new correction value of the curvature radius of the road before and after the road for which the new correction value is calculated becomes a predetermined reference value.

[0018] Furthermore, in this vehicle control device, it is preferable that the correction value calculation unit calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed according to the type of road, and when the correction value calculation unit calculates a new correction value for one road on which the vehicle is traveling, it calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed for other roads based on the new correction value.

[0019] According to other embodiments, a storage medium for storing a vehicle control computer program is provided. This vehicle control computer program causes a processor to perform a process including the following steps: setting a reference curve speed as a reference for the vehicle's speed when traveling on a curve, based on the vehicle's speed and the radius of curvature of the road on which the vehicle travels; determining a target curve speed as the target speed at which the vehicle is controlled when traveling on a curve, based on the reference curve speed and a current correction value corresponding to the radius of curvature of the road; counting the number of times the vehicle's speed changes from the target curve speed due to driver operation while the vehicle is traveling on a curve; each time the number of changes is counted, calculating a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle's speed from the target curve speed due to driver operation; and determining the next target curve speed based on the reference curve speed and the new correction value corresponding to the radius of curvature of the road.

[0020] Furthermore, according to another embodiment, a vehicle control method is provided. This vehicle control method is executed by a vehicle control device and includes the following steps: setting a reference curve speed as a reference for the speed of the vehicle when traveling on a curve, based on the vehicle's speed and the radius of curvature of the road on which the vehicle travels; determining a target curve speed as the target speed at which the vehicle is controlled when traveling on a curve, based on the reference curve speed and a current correction value corresponding to the radius of curvature of the road; counting the number of times the vehicle's speed changes from the target curve speed due to driver operation while the vehicle is traveling on a curve; each time the number of changes is counted, calculating a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle's speed from the target curve speed due to driver operation; and determining the next target curve speed based on the reference curve speed and the new correction value corresponding to the radius of curvature of the road.

[0021] Invention Effects

[0022] The vehicle control device disclosed herein enables the vehicle to travel on a winding road with a lateral acceleration that satisfies each driver. Attached Figure Description

[0023] Figure 1 The diagrams are: (A) a diagram showing the operation of the driving planning device of this embodiment; (B) a diagram showing the vehicle traveling on a road including curves; (C) a diagram showing an example of the relationship between the radius of curvature and the reference curve speed; (D) a diagram showing the reference curve speed; and (D) a diagram showing the lateral acceleration.

[0024] Figure 2 (A) is a diagram illustrating the outline of the operation of the driving planning device in this embodiment, and (B) is a diagram illustrating the correction value calculation process when the vehicle is accelerated.

[0025] Figure 3 This is a schematic structural diagram of a vehicle equipped with the vehicle control system of this embodiment.

[0026] Figure 4 This is an example of an action flow diagram related to the target curve speed determination process of the driving planning device in this embodiment.

[0027] Figure 5 This is a diagram illustrating an example of the relationship between the correction value and the reference radius of curvature.

[0028] Figure 6 This diagram illustrates how the target curve speed determines the processing.

[0029] Figure 7This is an example of an action flowchart related to the correction value calculation and processing of the driving plan device in this embodiment.

[0030] Figure 8 This is a graph illustrating an example of the relationship between the correction factor and the number of changes.

[0031] Figure 9 (A) is a graph illustrating the calculation and processing of correction values ​​when the vehicle is decelerated, and (B) is a graph illustrating the new target cornering speed.

[0032] Figure 10 This is a graph illustrating the relationship between the correction value and the reference radius of curvature in variation example 1.

[0033] Explanation of reference numerals in the attached figures

[0034] 1. Vehicle Control System

[0035] 2 cameras

[0036] 3. Positioning information receiver

[0037] 4. Navigation device

[0038] 5. User Interface

[0039] 5a Display device

[0040] 10 vehicles

[0041] 11. Map information storage device

[0042] 12 Position estimation device

[0043] 13 Object detection device

[0044] 14. Driving lane planning device

[0045] 15 Driving plan device

[0046] 21 Communication Interface

[0047] 22 Memory

[0048] 23 processors

[0049] 231 Planning Department

[0050] 232 Setting Department

[0051] 233 Decision Department

[0052] 234 Counting Section

[0053] 235 Computing Department

[0054] 16 Vehicle control devices

[0055] 17. In-vehicle network Detailed Implementation

[0056] Figure 1 (A) Figure 1 (D) Figure 2 (A) and Figure 2 (B) is a diagram illustrating the outline of the operation of the driving planning device 15 in this embodiment. Figure 1 (A) is a diagram showing the vehicle 10 traveling on a road 50 including curves. Figure 1 (B) is a graph showing an example of the relationship between the radius of curvature and the reference curve speed. Figure 1 (C) is a diagram illustrating the reference curve speed. Figure 1 (D) is a graph illustrating lateral acceleration. Figure 2 (A) is a graph illustrating the calculation and processing of correction values ​​when vehicle 10 is accelerated. Figure 2 (B) is a diagram illustrating the new target cornering speed.

[0057] The following is for reference Figure 1 (A) Figure 1 (D) Figure 2 (A) and Figure 2 Section (B) provides an overview of the actions related to the vehicle control processing of the driving plan device 15 disclosed in this specification.

[0058] like Figure 1 As shown in (A), vehicle 10 is traveling on road 50. Road 50 has, in sequence, a straight section 50A, a curved section 50B, and a straight section 50C in the direction of travel of vehicle 10. Currently, vehicle 10 is traveling in section 50A.

[0059] The vehicle 10 has a driving plan device 15 and a vehicle control device 16. The driving plan device 15 generates a driving plan representing a predetermined driving trajectory of the vehicle 10 up to a predetermined point in time. The driving plan is represented 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 point in time.

[0060] The vehicle control device 16 controls various parts of the vehicle 10 to drive the vehicle based on the driving plan generated by the driving plan device 15. In addition, the driving plan device 15 sets a reference curve speed based on map information, the vehicle's speed, and the radius of curvature of the road 50 on which the vehicle 10 travels. The reference curve speed becomes the reference for the speed of the vehicle 10 when traveling on a curve.

[0061] The reference cornering speed represents the upper limit of speed for vehicle 10 when traveling on a road with a radius of curvature below the reference radius of curvature. The reference radius of curvature is determined based on the speed of vehicle 10. For example... Figure 1 As shown in (B), the reference curve speed decreases as the radius of curvature decreases. When the radius of curvature of the road is larger than the reference radius of curvature, the driving planning device 15 does not set a reference curve speed. The speed of the vehicle 10 is determined based on the speed set by the driver.

[0062] Vehicle 10 travels on a curved road at a speed below the reference curve speed, thereby suppressing the lateral acceleration experienced by the driver to below a predetermined reference acceleration. Lateral acceleration is acceleration acting in a direction orthogonal to the direction of travel of vehicle 10, and is known as centrifugal force. Therefore, when vehicle 10 travels on a curved road, driver discomfort can be reduced. Furthermore, by suppressing lateral acceleration to below the predetermined reference acceleration, vehicle 10 can travel stably along a planned, predetermined trajectory.

[0063] In the straight section 50A, the driving plan device 15 generates a driving plan for the vehicle 10 in a manner that the vehicle travels at a driver-set speed, which is a speed indicated by the driver.

[0064] The radius of curvature of section 50B of the road curve is below the reference radius of curvature, therefore the driving plan device 15 sets a reference curve speed for section 50B. Within section 50B, the driving plan device 15 generates a driving plan for the vehicle 10 by driving at the reference curve speed.

[0065] Figure 1 (C) shows an example of the relationship between the speed and time of vehicle 10 based on a driving plan. In section 50A, vehicle 10 travels at a speed set by the driver; in section 50B, vehicle 10 travels at a reference cornering speed; and in section 50C, vehicle 10 travels at a speed set by the driver.

[0066] The reference curve speed is slower than the driver's set speed, so the vehicle 10 decelerates to the reference curve speed before the curve section 50B, and accelerates to the driver's set speed in section 50C after passing through section 50B.

[0067] like Figure 1 As shown in (D), the vehicle 10 travels in section 50B at a reference cornering speed, thereby reducing the lateral acceleration generated by the driver compared to the case where the vehicle 10 travels in section 50B at a speed set by the driver.

[0068] like Figure 2As shown in (A), when vehicle 10 is traveling in section 50B, the driver who feels that vehicle 10 is traveling slowly may sometimes accelerate the vehicle, causing the speed of vehicle 10 to increase compared to the reference curve speed.

[0069] Therefore, in interval 50B, the actual speed of vehicle 10 between time t1 and time t2 is greater than the planned speed. Additionally, in a portion of interval 50C, the actual speed of vehicle 10 is also greater than the planned speed.

[0070] The driving planning device 15 counts the number of times the speed of the vehicle 10 changes from the planned driving speed due to the driver's operation while the vehicle 10 is traveling on a curved road. Alternatively, the driving planning device 15 may count the number of times the speed of the vehicle 10 changes from the planned driving speed due to the driver's operation, based on the radius of curvature of the road.

[0071] Whenever the number of changes is counted, the driving plan device 15 calculates a correction value corresponding to the radius of curvature of the road relative to the reference curve speed, based on the correction coefficient determined according to the number of changes and the amount of change in the speed of the vehicle 10 which has changed from the speed of the driving plan due to the driver's operation.

[0072] like Figure 2 As shown in (A), when vehicle 10 is traveling on a road with the same radius of curvature as section 50B, driving planning device 15 determines a target curve speed based on a reference curve speed and a current correction value corresponding to the radius of curvature of the road. The target curve speed becomes the target speed at which vehicle 10 is controlled when it is traveling on a curve.

[0073] like Figure 2 As shown in (B), the new target cornering speed is adjusted to be greater than the previous baseline cornering speed, reflecting the driver's previous acceleration operation.

[0074] If, when vehicle 10 is traveling again on a road with the same radius of curvature as section 50B, the driver, sensing that vehicle 10 is traveling slowly, accelerates the vehicle, causing its speed to increase beyond the planned driving speed, the driving planning device 15 calculates a new correction value corresponding to the radius of curvature of the road relative to the target curve speed.

[0075] like Figure 2As shown in (B), when vehicle 10 travels again on a road with the same radius of curvature as section 50B, driving planning device 15 determines a new target curve speed based on the reference curve speed and the current correction value corresponding to the radius of curvature of the road. This new target curve speed is adjusted to be further increased than the previous target curve speed, reflecting the driver's previous acceleration operation.

[0076] As explained above, each time the number of changes is counted, the driving plan device 15 uses a correction value to determine the target cornering speed. This correction value is based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle 10's speed due to the driver's operation. Thus, the driving plan device 15 enables the vehicle to travel on the road with a lateral acceleration that satisfies each driver.

[0077] Figure 3 This is a schematic structural diagram of a vehicle 10 equipped with the vehicle control system 1 of this embodiment. The vehicle 10 includes a camera 2, a positioning information receiver 3, a navigation device 4, a user interface (UI) 5, a map information storage device 11, a location estimation device 12, an object detection device 13, a lane planning device 14, a driving planning device 15, and a vehicle control device 16. Furthermore, the vehicle 10 may also include a ranging sensor (not shown) such as a LiDAR sensor for determining the distance to objects surrounding the vehicle 10.

[0078] The camera 2, positioning information receiver 3, navigation device 4, UI 5, map information storage device 11, location estimation device 12, object detection device 13, driving lane planning device 14, driving planning device 15, and vehicle control device 16 can be communicatively connected via an in-vehicle network 17 based on a standard controller area network.

[0079] 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 representing the environment of a predetermined area in front of vehicle 10 at predetermined intervals. The camera images can represent road features, such as roads and lane markings, within the predetermined area in front of vehicle 10. Camera 2 has an imaging optical system comprising a 2D detector composed of an array of photoelectric conversion elements sensitive to visible light, such as CCD or C-MOS, and an image of the area to be photographed on the 2D detector.

[0080] Whenever camera 2 captures an image, it outputs the image and the time of capture via the in-vehicle network 17 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.

[0081] The positioning information receiver 3 outputs positioning information indicating the current location 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 to the navigation device 4 and the map information storage device 11, etc.

[0082] 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 indicating the current position of the vehicle 10 input from the positioning information receiver 3. The navigation route includes position-related information such as right turns, left turns, merging, and branching. The navigation device 4 regenerates the 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. 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 17.

[0083] UI5 is an example of a notification unit. Controlled by navigation device 4, driving plan device 15, and vehicle control device 16, UI5 notifies the driver of driving information of vehicle 10. Driving information includes the vehicle's current position, road speed limits, navigation routes, and other information related to the vehicle's current and future paths. To display driving information, UI5 has a display device 5a such as an LCD or touch panel. Additionally, UI5 may 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, the destination location, routes, vehicle speed (driver-set speed), and other control information. UI5 serves as an input device for inputting driver-operated information about vehicle 10, and may have, for example, a touch panel or operation buttons. For example, the driver sets the vehicle speed based on the speed limit of the road on which vehicle 10 is traveling. UI5 outputs the input operation information to navigation device 4, driving plan device 15, and vehicle control device 16 via in-vehicle network 17.

[0084] The map information storage device 11 stores wide-area map information covering a relatively wide range (e.g., a range of 10 to 30 km square) including the current position of the vehicle 10. This map information has high-precision map information, which includes 3D information of the road surface, road speed limits, road curvature radius, road features such as lane markings, and information indicating the types and locations of structures.

[0085] 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 of a relatively narrow area (e.g., a range of 100m square to 10km square) including the current location represented 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 17.

[0086] The position estimation device 12 estimates the position of the vehicle 10 at the time the camera image was captured based on road features surrounding the vehicle 10 as shown in the camera image. For example, the position estimation device 12 compares lane markings identified in the camera image with lane markings represented by 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. Furthermore, the position estimation device 12 estimates the driving lane of the road on which the vehicle 10 is located based on the lane markings represented by 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, etc.

[0087] The object detection device 13 detects other objects and their types (e.g., vehicles) around the vehicle 10 based on camera images, etc. 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. The object detection device 13 outputs object detection information to the driving lane planning device 14 and the driving planning device 15, etc., the object detection information including information indicating the type of detected other objects, information indicating their positions, and information indicating the driving lane.

[0088] 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. This generates a lane plan indicating the predetermined lane the vehicle 10 will be traveling in. The lane planning device 14 generates the lane plan, for example, with the vehicle 10 traveling 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.

[0089] The driving plan device 15 performs planning processing, setting processing, decision processing, counting processing, and calculation processing. Therefore, the driving lane planning device 14 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 driving lane planning device 14 to the in-vehicle network 17. The driving plan device 15 is an example of a vehicle control device.

[0090] 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.

[0091] All or part of the functions of the driving planning device 15 are implemented, for example, by functional modules that operate on a computer program running on the processor 23. The processor 23 has a planning unit 231, a setting unit 232, a decision unit 233, a counting unit 234, and a calculation unit 235. 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.

[0092] The planning unit 231 performs driving plan processing, which generates a driving plan representing the predetermined driving trajectory of vehicle 10 up to a predetermined time point (e.g., 5 seconds) based on a driving lane plan, map information, the current position of vehicle 10, surrounding environment information, and vehicle status information at a driving plan generation time set at a predetermined period. The surrounding environment information includes the positions and speeds of other vehicles traveling around vehicle 10. The vehicle status information includes the current position, speed, acceleration, and direction of travel of vehicle 10. The driving plan is represented as a set of the target position of vehicle 10 and the speed of a target vehicle at that target position at each time point from the current time to the predetermined time point. Preferably, the period for generating the driving plan is shorter than the period for generating the driving lane plan. The driving plan device 15 generates the driving plan at intervals that maintain a predetermined distance or more between vehicle 10 and other objects (vehicles, etc.). Whenever a driving plan is generated, the driving plan device 15 outputs the driving plan to the vehicle control device 16. Other operations of the driving plan device 15 will be described later.

[0093] 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 device 15. For example, the vehicle control unit 16 calculates the vehicle 10's steering angle, acceleration, and angular acceleration based on the driving plan, speed, and yaw rate, and sets the steering amount, accelerator opening, or braking amount in a manner consistent with these steering angle, acceleration, and angular acceleration. Furthermore, the vehicle control unit 16 outputs a control signal corresponding to the set steering amount to the actuator (not shown) controlling the steering wheels of the vehicle 10 via the in-vehicle network 17. 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 17. Alternatively, the vehicle control unit 16 outputs a control signal corresponding to the set braking amount to the vehicle 10's brakes (not shown) via the in-vehicle network 17.

[0094] 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, and the vehicle control device 16 are, 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, and the vehicle control device 16 are described as different devices, but all or part of these devices may also be constituted as a single device.

[0095] Figure 4This is an example of an operation flowchart related to the target curve speed determination process of the driving planning device 15 in this embodiment. Hereinafter, refer to... Figure 4 The target corner speed determination process of the driving plan device 15 will be explained. At the target corner speed determination time with a predetermined cycle, the driving plan device 15... Figure 4 The flowchart shown illustrates the execution of the target curve speed determination process. The optimal execution cycle for this target curve speed determination process is below the time of driving plan generation.

[0096] First, the setting unit 232 refers to map information and determines whether the radius of curvature of the road in the section where the driving plan will be generated is less than or equal to a reference radius of curvature (step S101). The setting unit 232 is an example of a reference curve speed setting unit. Referring to map information, the setting unit 232 obtains the radius of curvature of the road in the section where the driving plan will be generated, for the road on which the vehicle 10 is currently traveling. Here, the setting unit 232 may also determine the section where the driving plan will be generated based on the current position of the vehicle 10 and the vehicle 10's most recent average speed. Alternatively, the setting unit 232 determines the reference radius of curvature based on the speed of the vehicle 10. For example, the setting unit 232 may refer to a table stored in memory 22 that records the relationship between speed and the reference radius of curvature, and determine the reference radius of curvature based on the speed of the vehicle 10. If the section where the driving plan will be generated includes a road with a radius of curvature less than or equal to the reference radius of curvature, the setting unit 232 determines that the radius of curvature of the road is less than or equal to the reference radius of curvature (step S101 - Yes). On the other hand, if the area in which the driving plan is subsequently generated does not include roads with a curvature radius below the reference curvature radius, it is determined that the curvature radius of the road is not below the reference curvature radius (step S101 - No).

[0097] If it is determined that the radius of curvature of the road is below a reference radius of curvature (step S101 - Yes), the setting unit 232 sets a reference cornering speed as a reference for the speed of the vehicle 10 when traveling on a curved road (step S102). The reference cornering speed represents the upper limit speed of the vehicle 10 when traveling on a road with a radius of curvature below the reference radius of curvature. The setting unit 232 calculates the reference cornering speed based on the radius of curvature of the road, the reference acceleration allowed as lateral acceleration, and the mass of the vehicle 10. The reference acceleration preferably represents an upper limit value of the magnitude of lateral acceleration that a normal adult driver would not feel uncomfortable. The reference acceleration can also be determined according to the speed set by the driver. The mass of the vehicle 10 can, for example, be the mass of the vehicle 10 when carrying normal passengers and cargo. Figure 1 As shown in (B), the reference curve speed decreases as the radius of curvature decreases.

[0098] Next, the decision unit 233 determines the target curve speed (step S103) based on the reference curve speed and the current correction value corresponding to the radius of curvature of the road, thus determining the target curve speed at which the vehicle 10 is controlled when traveling on the curve, and ends the series of processes. The decision unit 233 is an example of a target curve speed determination unit. The planning unit 231 uses the target curve speed to generate a driving plan for traveling on the curve. The calculation process of the correction value will be described later.

[0099] On the other hand, if it is determined that the radius of curvature of the road is not below the reference radius of curvature (step S101 - No), the series of processes ends. The planning unit 231 uses the speed set by the driver to generate a driving plan.

[0100] Next, refer to the following Figure 5 and Figure 6 The process by which the decision unit 233 determines the target curve speed in step S103 described above will be explained.

[0101] The decision unit 233 determines the target curve speed Va based on the reference curve speed and the current correction value corresponding to the radius of curvature of the road. The target curve speed Va becomes the target speed at which the vehicle 10 is controlled when it is traveling on a curve. Specifically, as shown in the following equation (1), the decision unit 233 calculates the sum of the reference curve speed Vb and the current correction value M corresponding to the radius of curvature of the road as the target curve speed Va.

[0102] [Mathematical Expression 1]

[0103] Va=Vb+M (1)

[0104] Figure 5 This diagram illustrates an example of the relationship between the correction value and the reference radius of curvature. In this embodiment, the correction value is calculated based on the road's radius of curvature. For example, the calculation unit 235 may divide the radius of curvature into sections of 10m each, and calculate the correction value for each section. The correction value is the same for the radii of curvature contained in a single section. The initial value of the correction value is zero. In this case, the target curve speed is consistent with the reference curve speed. Figure 5 In the example shown, the correction value is positive, but it can also be negative. It is preferable to set an upper limit for the absolute value of the correction value. This upper limit can be determined, for example, through design or experimentation. Alternatively, the upper limit can be determined based on the radius of curvature of the road.

[0105] Figure 6This diagram illustrates the process for determining the target curve speed. The setting unit 232 determines the reference radius of curvature based on the driver's set speed, which is the speed of the vehicle 10. Since the radius of curvature of the road in the section where the driving plan is subsequently generated is less than or equal to the reference radius of curvature, the setting unit 232 sets a reference curve speed as a reference to the speed of the vehicle 10 when traveling on the curve. Then, the setting unit 232 calculates the sum of the reference curve speed and the current correction value corresponding to the road's radius of curvature as the target curve speed. Figure 6 In the example shown, the target curve speed is slower than the driver's set speed. Therefore, the planning unit 231 generates a driving plan to decelerate to the target curve speed before entering the section of the road with a curvature radius below the reference curvature radius (the section of the road with a curve), and accelerate to the driver's set speed after passing through the section of the road with a curve.

[0106] Next, refer to the following Figure 7 The calculation and processing of the correction value are explained. Figure 7 This is an example of an operation flowchart related to the correction value calculation process of the driving plan device 15 in this embodiment. Whenever the vehicle 10 passes through a turning range where the target cornering speed has been determined in the target cornering speed determination process, the driving plan device 15 proceeds according to... Figure 7 The flowchart shown illustrates the execution of correction value calculation.

[0107] First, when the vehicle 10 passes through the turning section, the counting unit 234 determines whether the absolute value of the change in the speed of the vehicle 10, which has changed from the target curve speed due to the driver's operation, is greater than or equal to the reference change amount (step S201).

[0108] Figure 2 (A) illustrates an example where the speed of vehicle 10 changes from the target curve speed due to the driver's acceleration operation within a section of a curved road. The change in speed S, where the difference between the actual speed of vehicle 10 and the target curve speed deviates from a predetermined reference speed difference within the section of the curved road, is calculated using the following equation (2). Here, t1 is the moment when the speed of vehicle 10 begins to deviate from the planned speed by a reference deviation amount. t2 is the moment when vehicle 10 reaches the end of the section of the curved road while its speed has deviated from the planned speed by a reference deviation amount. acc It is the difference between the speed of vehicle 10 and the target curve speed.

[0109] [Mathematical Expression 2]

[0110]

[0111] When the speed of vehicle 10 changes from its target curve speed due to the driver's acceleration operation, the change in speed S is positive. On the other hand, when the speed of vehicle 10 changes from its target curve speed due to the driver's deceleration operation (see reference...). Figure 9 (A)), the change in velocity S has a negative value.

[0112] The reference change can be determined by considering the deviation of the vehicle 10's speed when traveling at a constant speed. Similarly, the reference deviation can be determined by considering the deviation of the vehicle 10's speed when traveling at a constant speed.

[0113] If the change in the speed of vehicle 10 is greater than or equal to the baseline change (step S201 - Yes), the counting unit 234 increments the number of changes in the speed of vehicle 10 from the target curve speed due to the driver's operation by one (step S202). The initial value of the number of changes is zero.

[0114] Next, each time the number of changes is counted, the calculation unit 235 calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, based on the correction coefficient determined according to the number of changes and the change in the speed of the vehicle 10 due to the change in the target curve speed caused by the driver's operation (step S203), and ends the series of processes. The calculation unit 235 is an example of a correction value calculation unit.

[0115] In addition, if the change in the speed of vehicle 10 is not greater than the reference change (step S201 - No), the series of processes ends.

[0116] Next, refer to the following Figure 8 The process of calculating new correction values ​​by the calculation unit 235 will be explained. Figure 8 This is a diagram illustrating an example of the relationship between the correction factor and the number of changes. The relationship between the correction factor and the number of changes has a first region where the correction factor increases with the number of changes, a second region where the correction factor increases significantly more than in the first region, and a third region where the correction factor increases less than in the second region. During the learning process of the correction value, in the initial stage, there is a possibility that the driver's acceleration / deceleration operations are accidental, so the correction factor is decreased (first region). Furthermore, when it is determined that the driver's acceleration / deceleration operations are habitual, the correction factor is increased (second region). However, a substantial upper limit is set on the correction factor (third region). For example, a sigmoid function can be used as the correction factor. In this embodiment, the correction factor has a positive value.

[0117] The calculation unit 235 calculates the sum of the products of each correction coefficient and the change in vehicle speed when the speed of vehicle 10 changes from the target curve speed due to the driver's operation, as a new correction value.

[0118] The product of various correction factors and the change in vehicle speed L when the speed of vehicle 10 changes from the target curve speed due to driver operation. i It is obtained through the following equation (3). Here, i is the number of changes, and α is... i It is the correction factor that is changed for the i-th time, S i This represents the change in velocity during the i-th change. Furthermore, the initial value of the correction coefficient α0 is zero.

[0119] [Mathematical Expression 3]

[0120] L i =α i S i (3)

[0121] When the driver accelerates, the change in speed S i If positive, the correction factor α i It is either zero or a positive value, therefore, the product L i It is zero or positive. On the other hand, when the driver decelerates, the change in speed S i If negative, the correction factor α i It is either zero or a positive value, therefore, the product L i It can be zero or negative.

[0122] The new correction value M is obtained by the following equation (4). Here, m is the current number of changes.

[0123] [Mathematical Expression 4]

[0124]

[0125] Next, refer to the following Figure 2 (A) and Figure 2 (B) will be used to illustrate the operation of the driving planning device 15 in the case where the speed of vehicle 10 changes from the target curve speed due to the driver's acceleration operation in the section of the road where vehicle 10 is turning.

[0126] like Figure 2 As shown in (A), when the vehicle 10 is traveling on a road with a curvature radius below the reference curvature radius, the driving planning device 15 determines a target curvature speed based on the reference curvature speed and the current correction value corresponding to the curvature radius of the road. The target curvature speed becomes the target speed at which the vehicle 10 is controlled when traveling on the road with a curvature radius.

[0127] If, while the vehicle 10 is traveling on a curved road, the driver, sensing that the vehicle 10 is traveling slowly, accelerates the vehicle, causing the vehicle 10's speed to increase beyond the target curve speed, the driving plan device 15 calculates a new correction value corresponding to the road's radius of curvature relative to the target curve speed.

[0128] Furthermore, the driving of vehicle 10 within the section of the road with bends is sometimes based on multiple driving plans. In this case, for multiple driving sections traversing the section of the road with bends, a new correction value is determined based on the change in speed between the starting time t1 and time t2.

[0129] like Figure 2 As shown in (B), when vehicle 10 subsequently travels on a road with the same radius of curvature as before, driving planning device 15 determines a new target cornering speed based on a reference cornering speed and a current correction value corresponding to the road's radius of curvature. This new target cornering speed is adjusted to be greater than the previous target cornering speed, reflecting the driver's previous acceleration operation.

[0130] In addition, in driving plans that include a new target cornering speed, since the speed of vehicle 10 on the road where it is turning is greater than the previous target cornering speed, the timing at which the speed of vehicle 10 begins to decrease from the speed set by the driver is sometimes delayed compared to before.

[0131] Next, refer to the following Figure 9 (A) and Figure 9 (B) will explain an example of the operation of the driving planning device 15 when the speed of vehicle 10 changes from the target curve speed due to the driver's deceleration operation in the section of the road where vehicle 10 is turning.

[0132] Figure 9 (A) is a graph illustrating the calculation and processing of correction values ​​when vehicle 10 is decelerated. Figure 9 (B) is a diagram illustrating the new target cornering speed.

[0133] like Figure 9 As shown in (A), when the vehicle 10 is traveling on a road with a curvature radius below the reference curvature radius, the driving planning device 15 determines a target curvature speed based on the reference curvature speed and the current correction value corresponding to the curvature radius of the road. The target curvature speed becomes the target speed at which the vehicle 10 is controlled when traveling on the road with a curvature radius.

[0134] The correction value for the case where vehicle 10 is decelerated is calculated in the same way as for the case where vehicle 10 is accelerated. Furthermore, in Figure 9In the example shown in (A), t1 is the moment when the speed of vehicle 10 deviates from the planned speed by more than the reference deviation amount. t2 is the moment when the speed of vehicle 10 deviates from the planned speed by more than the reference deviation amount, or the moment when vehicle 10 reaches the end of the section of the road where the speed of vehicle 10 deviates from the planned speed by more than the reference deviation amount.

[0135] If, while the vehicle 10 is traveling on a curved road, the driver, sensing that the vehicle 10 is traveling too fast, decelerates the vehicle, causing its speed to decrease below the target curve speed, the driving planning device 15 calculates a new correction value corresponding to the radius of curvature of the road relative to the target curve speed. As described above, the new correction value is determined based on the change in speed between the start time t1 and the end time t2 of the speed deviation.

[0136] like Figure 9 As shown in (B), when vehicle 10 subsequently travels on a road with the same radius of curvature as before, driving planning device 15 determines a new target curve speed based on a reference curve speed and a current correction value corresponding to the road's radius of curvature. This new target curve speed is adjusted to be lower than the previous target curve speed, reflecting the driver's deceleration operation in the previous instance.

[0137] In addition, in driving plans that include a new target cornering speed, since the speed of vehicle 10 on the road where it is turning is lower than the previous target cornering speed, the timing at which the speed of vehicle 10 begins to decrease from the driver's set speed may sometimes be earlier than before.

[0138] As explained above, the driving planning device of this embodiment determines the target cornering speed using a correction value each time the number of changes is counted. This correction value is calculated based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle's speed due to the driver's operation. Thus, the driving planning device enables the vehicle to travel on a winding road with a lateral acceleration satisfactory to each driver.

[0139] Next, modifications 1 and 2 of the driving planning device of this embodiment will be described below.

[0140] Figure 10 This is a diagram illustrating the relationship between the correction value and the reference radius of curvature in Modification Example 1. In this modification example, when the calculation unit 235 calculates a new correction value, it corrects the current correction value of the radius of curvature of the road before and after the new correction value in such a way that the difference h between the current correction value and the new correction value of the radius of curvature of the road before and after the new correction value is determined becomes a predetermined reference value.

[0141] like Figure 10 As shown, a new correction value is calculated for the curvature radius r1. The difference between the current correction value and the new correction value for the curvature radius of the roads before and after curvature radius r1 is greater than the predetermined reference value. This new correction value is discontinuous with respect to the current correction values ​​for the curvature radius of the roads before and after curvature radius r1.

[0142] Therefore, the calculation unit 235 connects the correction values ​​of positions r2 and r3 at predetermined curvature radii that are forward and backward from curvature radius r1 with the new correction value of curvature radius r1 using a straight line (or curve), and uses the correction value represented by this straight line (or curve) as the current correction value of the curvature radius of the road before and after curvature radius r1. Thus, the new correction value becomes continuous with respect to the correction values ​​of the curvature radius of the road before and after curvature radius r1, and therefore the target curve speed of the vehicle 10 when traveling on roads with different curvature radii is set to a continuous value.

[0143] In addition, Figure 10 In the example shown, the difference h between the current correction value and the new correction value of the radius of curvature is positive, but the above explanation also applies to the case where the difference h is negative.

[0144] Next, a variation 2 of the driving planning device of this embodiment will be described. In this variation, the calculation unit 235 calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, according to the type of road. When the calculation unit 235 calculates a new correction value for one road on which the vehicle 10 travels, it calculates new correction values ​​corresponding to the radius of curvature of the road relative to the reference curve speed for other roads based on this new correction value.

[0145] As types of roads, there are highway mainlines, junction roads connecting different highways, and exchange roads connecting highways with ordinary roads. These roads may have sections with bends.

[0146] The calculation unit 235 can, for example, calculate the correction value for roads with fewer changes by multiplying the correction value of roads with more changes by a predetermined coefficient. Thus, appropriate new correction values ​​can be obtained for roads with the same radius of curvature, based on the type of road.

[0147] For example, when calculating the correction value Mi for an interchange based on the correction value Mj for the intersecting road, Mi = Mj × β. Here, β can be set, for example, to β = 0.7.

[0148] Furthermore, when calculating the mainline correction value Mh based on the correction value Mj of the intersecting roads, let Mh = Mj × β. Here, β can be set, for example, to β = 0.8.

[0149] Furthermore, when calculating the correction value Mj for the intersecting road based on the correction value Mi for the connecting road, let Mj = Mi × β. Here, β can be set, for example, to β = 0.5.

[0150] Furthermore, when calculating the mainline correction value Mh based on the correction value Mi of the communication path, Mh is set as Mh = Mi × β. Here, β can be set, for example, as β = 0.4.

[0151] Furthermore, when calculating the correction value Mj for intersecting roads based on the correction value Mh of the main road, let Mj = Mh × β. Here, β can be set to β = 0, for example.

[0152] Furthermore, when calculating the correction value Mi of the AC path based on the correction value Mh of the main line, Mi is set as Mi = Mh × β. Here, β can be set, for example, as β = 0.

[0153] In this disclosure, the vehicle control device, vehicle control computer program, and vehicle control method described above can be appropriately modified without departing from the spirit of this disclosure. Furthermore, the technical scope of this disclosure is not limited to these embodiments, but extends to the invention as described in the claims and its equivalents.

[0154] For example, when the vehicle is in adverse weather conditions such as rain or snow, the correction factor can be reduced to zero or less compared to favorable weather conditions such as sunny days. This is because the road surface is wet in adverse weather, resulting in different driving conditions compared to 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 reference curve speed setting unit sets a reference curve speed based on the vehicle's speed and the radius of curvature of the road on which the vehicle travels. The reference curve speed becomes a reference for the speed of the vehicle when it travels on a curve. The target curve speed determination unit determines the target curve speed based on the reference curve speed and the current correction value corresponding to the radius of curvature of the road. The target curve speed becomes the target speed at which the vehicle is controlled when it is traveling on a curve. The counting unit counts the number of times the vehicle's speed changes from the target curve speed due to the driver's operation while the vehicle is traveling on a curved road. as well as The correction value calculation unit, each time the number of changes is counted, calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, based on a correction coefficient determined according to the number of changes and the amount of change in the vehicle's speed due to the driver's operation. The target curve speed determination unit determines the next target curve speed based on the reference curve speed and the new correction value corresponding to the radius of curvature of the road. The correction value calculation unit calculates the new correction value as the sum of the products of each correction coefficient and the change in vehicle speed when the vehicle's speed changes from the target curve speed due to the driver's operation. When the correction value calculation unit calculates the new correction value, it corrects the current correction value of the radius of curvature of the road before and after the new correction value in such a way that the difference between the current correction value and the new correction value of the radius of curvature of the road before and after the new correction value is a predetermined reference value or less.

2. The vehicle control device according to claim 1, characterized in that, The relationship between the correction coefficient and the number of changes includes a first region where the correction coefficient increases with the number of changes, a second region where the correction coefficient increases more than the first region with the number of changes, and a third region where the correction coefficient increases less than the second region with the number of changes.

3. The vehicle control device according to claim 1 or 2, characterized in that, The correction value calculation unit calculates a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed, according to the type of road. When the correction value calculation unit calculates the new correction value for one road on which the vehicle is traveling, it calculates, based on the new correction value, a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed for other roads.

4. A non-transitory storage medium storing a computer-readable vehicle control computer program, characterized in that, The vehicle control computer program causes the processor to perform processing including the following steps: Based on the vehicle's speed and the radius of curvature of the road the vehicle is traveling on, a reference curve speed is set, which becomes the reference for the vehicle's speed when traveling on a curve. Based on the baseline curve speed and the current correction value corresponding to the radius of curvature of the road, a target curve speed is determined, which becomes the target speed at which the vehicle is controlled when it is traveling on a curve. While the vehicle is traveling on a curved road, the number of times the vehicle's speed changes from the target curve speed due to the driver's operation is counted. as well as Each time the number of changes is counted, a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed is calculated based on a correction factor determined according to the number of changes and the amount of change in the vehicle's speed from the target curve speed due to driver operation. The vehicle control computer program determines the next target cornering speed based on the reference cornering speed and the new correction value corresponding to the radius of curvature of the road. The new correction value is calculated as the sum of the products of each correction coefficient and the change in vehicle speed when the vehicle's speed changes from the target curve speed due to the driver's operation. In the case of obtaining the new correction value, the current correction value of the radius of curvature of the road before and after obtaining the new correction value is corrected in such a way that the difference between the current correction value and the new correction value of the radius of curvature of the road before and after obtaining the new correction value becomes a predetermined reference value.

5. A vehicle control method, wherein the vehicle control method is a vehicle control method executed by a vehicle control device, characterized in that, Includes the following steps: Based on the vehicle's speed and the radius of curvature of the road the vehicle is traveling on, a reference curve speed is set, which becomes the reference for the vehicle's speed when traveling on a curve. Based on the baseline curve speed and the current correction value corresponding to the radius of curvature of the road, a target curve speed is determined, which becomes the target speed at which the vehicle is controlled when it is traveling on a curve. While the vehicle is traveling on a curved road, the number of times the vehicle's speed changes from the target curve speed due to the driver's operation is counted. as well as Each time the number of changes is counted, a new correction value corresponding to the radius of curvature of the road relative to the reference curve speed is calculated based on a correction factor determined according to the number of changes and the amount of change in the vehicle's speed from the target curve speed due to driver operation. The vehicle control method determines the next target cornering speed based on the reference cornering speed and the new correction value corresponding to the radius of curvature of the road. The new correction value is calculated as the sum of the products of each correction coefficient and the change in vehicle speed when the vehicle's speed changes from the target curve speed due to the driver's operation. In the case of obtaining the new correction value, the current correction value of the radius of curvature of the road before and after obtaining the new correction value is corrected in such a way that the difference between the current correction value and the new correction value of the radius of curvature of the road before and after obtaining the new correction value becomes a predetermined reference value.

Images