Parking assistance method, parking assistance device, and computer program

Abstract

The present invention provides a parking assistance method that performs parking control in which a host vehicle is caused to automatically travel to a target parking position. Provided is a parking assistance method wherein: a first parking control method which is stored in association with a target parking position is used as a parking control method for controlling the travel of a host vehicle in parking control, so as to perform parking control to the target parking position at least once (S3); a reference parking control method, which is stored in advance in an external device provided outside the host vehicle, is received from the external device as a parking control method for controlling the travel of a vehicle other than the host vehicle in the parking control (S4); and after the host vehicle is parked at the target parking position using the first parking control method, a second parking control method obtained by correcting the first parking control method on the basis of the reference parking control method received from the external device is presented to a user of the host vehicle (S5, S6).

Description

Parking assistance method, parking assistance device, and computer program

[0001] The present invention relates to a parking assistance method, a parking assistance device, and a computer program.

[0002] Japanese Patent Application Laid-Open No. 2006-101494 describes a technique for changing a set speed for automatic parking depending on whether or not the driver applies the brakes while automatic parking is being performed.

[0003] Japanese Patent Application Laid-Open No. 2023-131293

[0004] However, when a parking assistance function that automatically drives a vehicle to a target parking position is implemented, if the parking method does not match the user's preferences or the parking environment, the user may be reluctant to use the parking assistance function. An object of the present invention is to improve user satisfaction with the parking assistance function.

[0005] According to one aspect of the present invention, there is provided a parking assistance method for performing parking control to automatically drive a host vehicle to a target parking position, in which parking control to the target parking position is performed at least once using a first parking control method that is stored in association with the target parking position as a parking control method for controlling the driving of the host vehicle in the parking control, and a reference parking control method that is pre-stored in an external device provided outside the host vehicle is received from the external device as a parking control method for controlling the driving of another vehicle other than the host vehicle in the parking control, and after parking the host vehicle at the target parking position using the first parking control method, a second parking control method that is obtained by modifying the first parking control method based on the reference parking control method received from the external device is presented to a user of the host vehicle.

[0006] According to the present invention, it is possible to improve user satisfaction with the parking assistance function.

[0007] FIG. 1 is a diagram showing an example of a schematic configuration of a parking assistance device according to an embodiment. (a) and (b) are schematic diagrams illustrating a parking assistance function. (a) to (e) are explanatory diagrams of examples of parking control parameters. FIG. 2 is a flowchart of an example of a parking assistance method according to an embodiment. FIG. 3 is a block diagram of an example of the functional configuration of the controller of FIG. 1. FIG. 4 is a diagram showing an example of a display screen that presents parking control parameters of a second parking control method to a user.

[0008] (First embodiment) (Configuration) Fig. 1 is a diagram showing an example of the schematic configuration of a parking assistance device according to an embodiment. A host vehicle 1 is equipped with a parking assistance device 10 that assists in parking the host vehicle 1 at a target parking position. The parking assistance device 10 performs parking control to automatically drive the host vehicle 1 along a target parking path from the current position of the host vehicle 1 to the target parking position. Here, parking control to automatically drive the host vehicle 1 along the target parking path to the target parking position refers to control to automatically drive the host vehicle 1 in whole or in part along the target parking path by controlling the steering angle, driving force, and braking force of the host vehicle 1.

[0009] The positioning device 11 measures the current position of the vehicle 1. The positioning device 11 includes, for example, a Global Navigation System (GNSS) receiver. Map data is stored in a map database (map DB) 12. The map data stored in the map database 12 may be, for example, map data for navigation or high-precision map data suitable for autonomous driving. The human-machine interface (HMI) 13 is an interface device that exchanges information between the parking assistance device 10 and a user. For example, the HMI 13 may include a display device visible to the user as an interface that presents visual information to the user. The HMI 13 may also include a speaker or a buzzer as an interface that presents auditory information to the user. The HMI 13 may also include an interface (such as a touch panel, button, switch, lever, dial, or keyboard) that accepts operational input from the user.

[0010] The external sensor 14 detects objects within a predetermined distance range from the host vehicle 1. The external sensor 14 detects the surrounding environment of the host vehicle 1, such as the relative position of the host vehicle 1 and an object present around the host vehicle 1, the distance between the host vehicle 1 and the object, and the direction in which the object is present. The external sensor 14 may include, for example, a camera that captures the surrounding environment of the host vehicle 1. The external sensor 14 may also include a distance measuring device such as a laser range finder, radar, LiDAR, or sonar. The vehicle sensor 15 detects various information (vehicle information) about the host vehicle 1. For example, the vehicle sensor 15 may include a vehicle speed sensor that detects the traveling speed of the host vehicle 1, a three-axis acceleration sensor that detects the acceleration (including deceleration) of the host vehicle 1 in three axial directions, and a sensor that detects the steering angle of the steering wheel and the steering angle of the steered wheels. The communication device 16 wirelessly communicates with an external device (e.g., a server device) 20 provided outside the host vehicle 1. The communication method used by the communication device 16 may be, for example, wireless communication using a public mobile phone network, vehicle-to-vehicle communication, road-to-vehicle communication, or satellite communication.

[0011] The controller 17 is an electronic control unit that controls parking of the host vehicle 1. The controller 17 includes a processor 17a and peripheral components such as a storage device 17b. The processor 17a may be, for example, a CPU or an MPU. The storage device 17b may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The functions of the controller 17 described below are realized, for example, by the processor 17a executing a computer program stored in the storage device 17b. The steering actuator 18a controls the steering direction and steering amount of the steering mechanism of the host vehicle 1 in response to a control signal from the controller 17 (the actuator is referred to as "ATCR" in the accompanying drawings). The accelerator actuator 18b controls the accelerator opening of a drive device such as an engine or a drive motor in response to a control signal from the controller 17. The brake actuator 18c activates a braking device in response to a control signal from the controller 17.

[0012] Next, the parking assistance function of the controller 17 will be described with reference to FIGS. 2( a) and 2(b). When using the parking assistance function of the parking assistance device 10, parking position data, which is information regarding a target parking position where the host vehicle 1 should be parked, is stored (registered) in advance in a storage device accessible to the host vehicle 1. In the example of FIG. 2(a), a parking position where the host vehicle 1 should be parked in the parking space 30 is stored as the target parking position. The storage device that stores the target parking position 31 may be, for example, the storage device 17b. Alternatively, for example, the parking position data 21 may be stored in an external device 20 provided outside the host vehicle 1 as a storage device accessible to the host vehicle 1, and the parking position data 21 may be received and used from the external device 20. In the following description, an example in which the parking position data is stored (registered) in the storage device 17b will be described.

[0013] The controller 17 extracts targets existing around the target parking position 31 as parking position data and stores (registers) them in the storage device 17b. In the following description, targets around the target parking position 31 stored in the storage device 17b are referred to as "learned targets." In FIG. 2( a), circles schematically represent learned targets. For example, when a user manually parks the host vehicle 1 at the target parking position 31, the controller 17 detects targets around the host vehicle 1 using the external sensor 14 and stores the targets as learned targets. For example, targets may be detected from a surrounding image obtained by capturing an image of the surroundings of the host vehicle 1 with a camera. For example, edge points or points (feature points) with characteristic shapes, such as edges or corners of targets such as road markings, road boundaries, and obstacles, in the captured image obtained by the camera, where the brightness of adjacent pixels changes by a predetermined amount or more, may be detected as targets.

[0014] The controller 17 stores parking position data including information about the learned targets in the storage device 17b. For example, the parking position data may include data representing the features of the learned targets (hereinafter referred to as "feature data") and data on the relative positional relationship between the target parking position 31 and the learned targets (hereinafter referred to as "relative position data"). As the relative position data, for example, the relative position of the learned targets with respect to the target parking position 31 may be stored. For example, the controller 17 may acquire the position of the learned targets detected when the host vehicle 1 is parked at the target parking position 31 as the relative position of the learned targets. The coordinates of the learned targets and the target parking position 31 in a coordinate system with a fixed point as the reference point (hereinafter referred to as "map coordinate system") may also be stored.

[0015] FIG. 2( b) is an explanatory diagram of an example of processing during implementation of parking control in which the controller 17 automatically drives the host vehicle 1 to the target parking position 31. When parking control begins, the controller 17 extracts targets around the host vehicle 1 using the external sensor 14. In the following description, targets around the host vehicle 1 extracted during implementation of parking control are referred to as "surrounding targets." The triangular plots in FIG. 2( b) represent surrounding targets. The controller 17 detects the target parking position 31 by matching the learned targets with the surrounding targets and associating identical feature points, and calculates the relative position of the host vehicle 1 with respect to the target parking position 31 based on the relative positional relationship between the surrounding targets detected during implementation of parking assistance and the host vehicle 1, and the relative positional relationship between the learned targets associated with the surrounding targets and the target parking position 31.

[0016] For example, the controller 17 calculates the position of the target parking position 31 on a coordinate system (hereinafter referred to as the "vehicle coordinate system") based on the current position of the vehicle 1. Note that if the coordinates of the learned targets and the target parking position 31 on the map coordinate system are stored in the storage device 17b, the coordinates of the target parking position 31 on the map coordinate system may be converted to coordinates on the vehicle coordinate system based on the positions of the surrounding targets detected when parking assistance is performed and the positions of the learned targets in the map coordinate system. The own position of the vehicle 1 on the map coordinate system may be obtained based on the positions of the surrounding targets detected when parking assistance is performed and the positions of the learned targets in the map coordinate system, and the relative position of the vehicle 1 with respect to the target parking position 31 may be calculated from the difference between the coordinates of the vehicle 1 and the coordinates of the target parking position 31 in the map coordinate system.

[0017] The controller 17 generates a target parking path 34 from the current position 33 of the vehicle 1 to the target parking position 31 based on the relative position of the vehicle 1 with respect to the target parking position 31. The controller 17 also generates a vehicle speed plan (target vehicle speed profile) that sets a target vehicle speed for the vehicle 1 at each position on the target parking path. The controller 17 controls the steering actuator 18a, accelerator actuator 18b, and brake actuator 18c so that the vehicle 1 travels along the target parking path 34 at a speed that conforms to the target vehicle speed profile to the target parking position 31 and stops there.

[0018] When generating the target parking path and the target vehicle speed profile, the controller 17 determines the position and shape of the target parking path and the vehicle speed included in the target vehicle speed profile according to the set values ​​of control parameters for controlling the traveling of the host vehicle 1 in parking control. In the following description, the control parameters for controlling the traveling of the host vehicle 1 in parking control may be referred to as "parking control parameters." Hereinafter, the manner and mode of parking control of the host vehicle 1 determined by the set values ​​of the parking control parameters may be referred to as "parking control method."

[0019] The elements of the parking control parameters may be, for example, the upper speed limit during parking, the deceleration rate during parking, the acceleration rate during starting, the steering speed of the steering mechanism, the turning position, the number of turning positions, the degree of deceleration (jerk) immediately before stopping, the detection sensitivity of obstacles around the host vehicle 1, the parking style for parking the host vehicle 1 at the target parking position 31, and parameters related to the driving route. For example, the parking style may include right-angle parking, parallel parking, and angle parking. Right-angle parking, parallel parking, and angle parking mean parking at a right angle, parallel parking, and angle parking, respectively, with respect to the traffic direction of the passageway facing the target parking position 31.

[0020] For example, the parameters related to the driving route may be the angle of entry into the parking space 30, whether or not stationary steering is possible, the target midpoint of the driving route, parameters of the complementary curve that forms the driving route, or the shape of the driving route itself. The parameters related to the driving route may also include parameters (hereinafter sometimes referred to as "driving range parameters") that limit the range of locations where the target parking route can be set (i.e., the range within which the host vehicle 1 may travel when parking at the target parking position 31).

[0021] FIG. 3A is an explanatory diagram of an example of a travel range parameter. Reference symbol PW denotes an aisle along which the host vehicle 1 parked in the parking space 30 travels, and the parking space 30 is provided facing the aisle PW. In the following description, the width direction of the aisle PW may be referred to as the "aisle width direction Dw." For example, the travel range parameter may include the width in the aisle width direction Dw of the aisle width range Rp indicated by hatching (which may be referred to as the "set aisle width Wp" in the following description). The aisle width range Rp is the range in the width direction of the aisle PW along which the host vehicle 1 travels toward the entrance of the parking space 30 (i.e., the aisle width direction range of the aisle PW within which the host vehicle 1 can depart from the parking space 30 in the aisle width direction Dw of the aisle PW).

[0022] For example, of the boundaries Bn and Bf at both ends of the aisle width range Rp, the near-end boundary Bn, which is closer to the parking space 30, may be set at the position of the aisle boundary of the aisle PW adjacent to the parking space 30. The far-end boundary Bf, which is farther from the parking space 30, may be set to be spaced apart from the near-end boundary Bn by the aisle set width Wp. For example, as shown in FIG. 3( b), if a relatively wide aisle set width Wp1 is set, the target driving path T1 may be set to pass through a point far from the parking space 30 in the aisle width direction Dw. As a result, the host vehicle 1 may get too close to an obstacle Ob (e.g., a fence) on the opposite side of the aisle PW from the parking space 30, causing the user to feel uncomfortable. If a relatively narrow aisle set width Wp2 is set as shown in FIG. 3( c), the target parking path T2 is set within the narrow aisle width range Rp, thereby preventing the host vehicle 1 from getting too close to an obstacle Ob on the opposite side of the aisle PW from the parking space 30.

[0023] For example, the travel range parameter may include the width of the entrance width range Re (hereinafter, sometimes referred to as the "entrance set width We") indicated by a bold line at the entrance EN of the parking space 30. The entrance width range Re is the range within the width direction of the entrance EN of the parking space 30 within which the host vehicle 1 travels (i.e., the range within the width direction of the entrance EN of the target parking space within which the host vehicle 1 can travel). For example, if a relatively wide entrance set width We1 is set as shown in FIG. 3(d), the host vehicle 1 may enter the parking space 30 at an entry angle that is significantly inclined from the front-to-rear direction of the parking space 30, as shown in path T3, which may cause discomfort to the user. If a relatively narrow entrance set width We2 is set as shown in FIG. 3(e), the number of turns increases and the travel speed decreases, making it possible to set a target parking path T4 in which the host vehicle 1 enters the parking space 30 from a direction closer to the front-to-rear direction of the parking space 30. The parking control parameters are not limited to the above examples, and various control parameters related to parking control may be employed.

[0024] The controller 17 may store parking method data, which is data on the parking control method (i.e., data on the setting values ​​of the parking control parameters), in advance in a storage device accessible by the host vehicle 1 (e.g., the storage device 17b or the external device 20) in association with the target parking position 31. For example, the parking control method may be stored in association with the parking position data in the storage device. When performing parking control to park the host vehicle 1 at the target parking position 31, the controller 17 reads out the parking control method stored in association with the target parking position 31 from the storage device, and generates a target parking path 34 and a target vehicle speed profile based on the read parking control method.

[0025] In this way, when parking control is performed based on a parking control method preset for the target parking position 31, the parking control may not be executed because the parking control method does not match the parking environment. Also, the parking control method may not match the user's preferences (for example, the vehicle speed may be too fast or insufficient, the vehicle may turn too many times, or the vehicle may come too close to an obstacle). If the parking control method does not match the user's preferences or the parking environment, the user may be reluctant to use the parking assistance function.

[0026] Therefore, in this embodiment, parking control method data 22 of a parking control method for controlling the driving of another vehicle other than the host vehicle 1 in parking control is stored in advance in an external device 20 provided outside the host vehicle 1. In the following description, the parking control method of the other vehicle stored in the external device 20 may be referred to as a "reference parking control method." The controller 17 receives the parking control method data 22 of the reference parking control method from the external device 20 via the communication device 16. After performing parking control to park the host vehicle 1 at the target parking position 31 at least once using the parking control method currently set for the target parking position 31 (hereinafter may be referred to as a "first parking control method"), the controller 17 modifies the first parking control method based on the reference parking control method received from the external device 20 to set a second parking control method and presents the second parking control method to the user of the host vehicle.

[0027] This provides an opportunity for the user to modify the first parking control method if the user is dissatisfied with the first parking control method that has been set. As a result, the user's satisfaction with the parking assistance function can be improved, and the use of the parking assistance function can be promoted. In the following description, the modified parking control method may be referred to as the "second parking control method." Furthermore, parking by manual driving may be referred to as "manual parking."

[0028] 4 is a flowchart of an example of a parking assistance method according to an embodiment. In step S1, the controller 17 stores the target parking position 31 in the storage device 17b. In step S2, the controller 17 stores a first parking control method to be used when parking the host vehicle 1 at the target parking position 31 in the storage device 17b in association with the target parking position 31. For example, the first parking control method may be an initial value of the parking control method to be used when parking the host vehicle 1 at the target parking position 31. In step S3, the controller 17 executes parking control to park the host vehicle 1 at the target parking position 31 using the first parking control method.

[0029] In step S4, the controller 17 receives from the external device 20 a reference parking control method for controlling the driving of vehicles other than the host vehicle 1 during parking control. The controller 17 may receive the reference parking control method from the external device 20 before executing parking control using the first parking control method in step S3. That is, step S4 may be executed before step S3. In step S5, the controller 17 modifies the first parking assistance method based on the reference parking control method to set a second parking control method. In step S6, the controller 17 presents the second parking control method to the user. If the user selects (approves) the second parking control method, in step S7, the controller 17 changes (updates) the parking control method set for the target parking position 31 (i.e., the parking control method stored in association with the target parking position 31) to the second parking control method. As a result, parking control executed thereafter will be executed based on the second parking control method.

[0030] Second Embodiment FIG. 5 is a block diagram of an example of the functional configuration of the controller 17. When a user operates the HMI 13 to instruct registration of the target parking position 31, the HMI control unit 50 outputs a map generation command to the map generation unit 55 to store learned target data for the target parking position 31 in the storage device 17b. When a user operates the HMI 13 to instruct start of parking control to the target parking position 31, the HMI control unit 50 outputs a control start command to start parking control to the target parking position 31 to the parking assistance control unit 51. The image conversion unit 52 converts images captured by the camera into overhead images viewed from a virtual viewpoint directly above the host vehicle 1. The image conversion unit 52 converts the captured images into overhead images at predetermined intervals and accumulates the converted overhead images along the travel route of the host vehicle 1 to generate a surrounding image that is an image of the area surrounding the host vehicle 1.

[0031] The self-position calculation unit 53 calculates the current position of the vehicle 1 on a map coordinate system as its own position by odometry (e.g., dead reckoning) based on the vehicle information output from the vehicle sensor 15. The target detection unit 54 detects targets from the surrounding image output from the image conversion unit 52. The target detection unit 54 may detect the positions of feature points of the targets and their image feature amounts as targets. The target detection unit 54 outputs the detected positions of feature points and image feature amounts as target data to the map generation unit 55 and the target parking position detection unit 57. In addition, the map generation unit 55 outputs the self-position acquired from the self-position calculation unit 53 to the map generation unit 55 and the target parking position detection unit 57 in synchronization with the detection of the targets. When the map generation unit 55 receives a map generation command from the HMI control unit 50 (i.e., when the target parking position 31 is registered), the map generation unit 55 generates parking position data 56 related to the target parking position 31 and stores the data in the storage device 17b. For example, the map generation unit 55 receives target data and the vehicle's own position on the map coordinate system synchronized with the target data from the target detection unit 54. The map generation unit 55 acquires position information of the target parking position 31 in the map coordinate system.

[0032] The map generation unit 55 generates relative position data based on the positions of the feature points included in the target object data, the position information of the host vehicle 1 synchronized therewith, and the position information of the target parking position 31. The map generation unit 55 acquires feature amount data from the target object data output from the target object detection unit 54, and stores parking position data 56 including the relative position data and feature amount data in the storage device 17b. When the map generation unit 55 stores the parking position data 56 in the storage device 17b, the parking method setting unit 62 associates parking control method data 63, which is data on the parking control method to be used when parking the host vehicle 1 at the target parking position 31 (i.e., data on setting values ​​of parking control parameters), with the parking position data 56 of the target parking position 31 and stores it in the storage device 17b. When the parking control method data 63 is initially stored for the target parking position 31, values ​​that are commonly used as parking control parameters may be stored as initial values, for example.

[0033] Next, upon receiving a control start command from the HMI control unit 50, the parking assist control unit 51 determines whether the current position of the vehicle 1 is near the registered target parking position 31. If the current position of the vehicle 1 is near the registered target parking position 31, the parking assist control unit 51 starts parking control. When parking control starts, the target parking position detection unit 57 receives target data output from the target detection unit 54 as target data of surrounding targets, and receives the own position of the vehicle 1 in the map coordinate system in synchronization with this. The target parking position detection unit 57 detects the target parking position 31 by matching the learned targets with the surrounding targets and associating targets with the same feature points. In other words, whether the target parking position 31 can be detected is determined based on whether matching between the learned targets and the surrounding targets is successful. If matching is successful (i.e., if the target parking position 31 is detected), the target parking position detection unit 57 calculates the relative position of the vehicle 1 with respect to the target parking position 31 based on the relative positional relationship between the surrounding targets and the vehicle 1 and the relative positional relationship between the learned targets associated with the surrounding targets and the target parking position 31.

[0034] Furthermore, the parking method setting unit 62 reads out parking control method data 63 stored in association with the parking position data 56 of the target parking position 31. The target trajectory generating unit 59 calculates a target parking path from the current position of the host vehicle 1 on the vehicle coordinate system to the target parking position 31 and a target vehicle speed profile based on the parking control method data 63 read out by the parking method setting unit 62. For example, if the number of turns or the position and shape of the driving path are set as parking control parameters, the target parking path may be calculated so that the number of turns, position, and shape of the target parking path are equal to these parameters. For example, if a target midpoint of the driving path is set as the parking control parameter, the target parking path may be calculated so that the target parking path passes through the target midpoint. If parameters of an interpolation curve forming the driving path are set as the parking control parameter, an interpolation curve having the set parameters may be calculated as the target parking path. If a parking style is set as the parking control parameter, the target parking path may be calculated so that the host vehicle 1 is parked in the set parking style. For example, if driving range parameters (passage setting width Wp, entrance setting width We) are set as parking control parameters, the target parking route may be calculated so as not to travel beyond the range limited by the driving range parameters.

[0035] For example, if the parking control parameters include an upper limit speed during parking, a deceleration rate during parking, an acceleration rate during starting, and a jerk immediately before stopping, the target vehicle speed profile may be calculated so that the upper limit speed, deceleration rate, acceleration rate, and jerk rate of the target vehicle speed profile are equal to these parameters. For example, if the parking control parameter includes a steering speed of the steering mechanism, the target vehicle speed profile may be calculated so that the vehicle travels along the target travel path while adhering to the set steering speed. For example, if the target trajectory generating unit 59 detects an obstacle around the host vehicle 1 during parking control, the target trajectory generating unit 59 may calculate a target vehicle speed profile so as to stop the host vehicle 1. The target trajectory generating unit 59 may set the obstacle detection sensitivity of the external sensor 14 based on the parking control parameters.

[0036] The steering control unit 60 controls the steering actuator 18a so that the host vehicle 1 travels along the target parking path. The vehicle speed control unit 61 controls the accelerator actuator 18b and the brake actuator 18c so that the vehicle speed of the host vehicle 1 changes in accordance with the target vehicle speed profile. When the host vehicle 1 reaches the target parking position 31, the host vehicle 1 is stopped and parking control is completed. The parking assist control unit 51 activates the parking brake and switches the shift position to the parking range.

[0037] Next, the operation of the parking method setting unit 62 will be described. After performing parking control to park the host vehicle 1 at the target parking position 31 at least once, the parking method setting unit 62 modifies the parking control method represented by the parking control method data 63 currently stored in the storage device 17b and proposes the modified parking control method to the user of the host vehicle 1. In the following description, the parking control method before modification may be referred to as the "first parking control method," and the modified parking control method may be referred to as the "second parking control method."

[0038] In order to modify the first parking control method, the parking method setting unit 62 receives parking control method data 22 of a reference parking control method that controls the driving of other vehicles in parking control from the external device 20 via the communication device 16. The parking method setting unit 62 may receive parking control method data 22 of a reference parking control method used to control the parking of other vehicles at the same parking position as the target parking position 31 stored in the storage device 17b, or may receive parking control method data 22 of a reference parking control method used to control the parking of other vehicles at a parking position different from the target parking position 31. The parking method setting unit 62 sets the second parking control method by modifying the first parking control method based on the received reference parking control method. For example, the first parking control method may be modified by replacing the setting values ​​of the parking control parameters of the first parking control method with the values ​​of the received reference parking control method. For example, the first parking control method may be modified by taking a weighted average of the setting values ​​of the parking control parameters of the first parking control method and the values ​​of the received reference parking control method.

[0039] When the parking method setting unit 62 proposes the second parking control method, the HMI control unit 50 displays (presents) parking control parameters of the second parking control method on the display device of the HMI 13. The HMI control unit 50 may display the parking control parameters of the second parking control method on a mobile terminal device carried by the user. For example, when the shape parameters of a target parking path are presented as the parking control parameters, the target parking path generated based on the shape parameters may be superimposed on the surrounding image. Furthermore, when the parking control parameters related to the time required for parking (e.g., driving speed, deceleration, acceleration, steering speed, number of turns, jerk just before stopping, obstacle detection sensitivity, etc.) are presented, a GUI visually representing the values ​​of these parking control parameters may be displayed on the display device of the HMI 13.

[0040] 6 is a diagram showing an example of a display screen 70 that presents parking control parameters of the second parking control method to the user. For example, the display screen 70 may include CG of an indicator 71 that visually represents each parking control parameter of the second parking control method (in the example of FIG. 6, the driving speed, deceleration, acceleration, steering speed, and number of turns). For example, the indicator 71 may include a mark 72 that represents the value of the parking control parameter of the first parking control method currently stored in the storage device 17b, and a mark 73 that represents the value of the parking control parameter of the second parking control method. Furthermore, for example, the HMI control unit 50 may display a video that represents the vehicle behavior of the host vehicle 1 when parking control is performed based on the second parking control method.

[0041] When the user selects (approves) the proposed second parking control method, the parking method setting unit 62 updates (replaces) the first parking control method stored in the storage device 17b with the second parking control method. In subsequent parking control, the target trajectory generation unit 59 calculates a target parking path and a target vehicle speed profile based on the second parking control method.

[0042] The timing at which the parking method setting unit 62 proposes the second parking control method to the user may be, for example, when the initial parking control for parking the host vehicle 1 at the target parking position 31 using the first parking control method is completed. The parking method setting unit 62 may also propose the second parking control method when the user selects to park the host vehicle 1 at the target parking position 31 by manual parking after parking the host vehicle 1 at the target parking position 31 using the first parking control method. For example, the second parking control method may be proposed when the user cancels the parking control of the host vehicle 1 at the target parking position 31 using the first parking control method. The parking method setting unit 62 may also propose the second parking control method when the user completes parking the host vehicle 1 at the target parking position 31 by manual parking after parking the host vehicle 1 at the target parking position 31 using the first parking control method.

[0043] The parking method setting unit 62 may periodically propose the second parking control method. In this case, when parking the vehicle 1 at the target parking position 31, a proposal of the second parking control method may be displayed on a user interface screen that receives, via the HMI 13, a user's operation to select automatic parking using parking control (e.g., an operation to instruct the start of parking control) when the vehicle 1 is parked at the target parking position 31. The parking method setting unit 62 may propose the second parking control method at regular time intervals. The parking method setting unit 62 may propose the second parking control method according to the number of times parking control has been performed. For example, the number of times parking control has been performed may be counted and the second parking control method may be proposed once each time a predetermined number of parking control operations have been performed. In this case, the number of times parking control has been performed may be counted individually for each target parking position and the second parking control method may be proposed according to the number of times parking control has been performed at each target parking position. Alternatively, the total number of times parking control has been performed may be counted regardless of which target parking position the vehicle is parked at and the second parking control method may be proposed according to the total number of times.

[0044] The parking method setting unit 62 may set (change) the frequency of periodic proposals of the second parking control method according to a history of whether the user accepted (approved) the proposal of the second parking control method by the parking assistance device 10. For example, if the user accepted the proposal of the second parking control method, the period until the next periodic proposal may be extended or the frequency of the proposal may be reduced. Furthermore, the external device 20 may aggregate histories of whether multiple users accepted the proposal of the second parking control method, and the frequency of proposals of the second parking control method may be set according to the acceptance results of the proposals by multiple users.

[0045] For example, the proposal frequency of the second parking control method may be set based on the average frequency with which multiple users accept the plan (e.g., two to three times a month). For example, the proposal frequency may be set to the average frequency with which multiple users accept the plan. The parking method setting unit 62 may receive the results of the multiple users' acceptance of the proposals from the external device 20 and set the proposal frequency, or the external device 20 may set the frequency with which the second parking control method is proposed, and the parking method setting unit 62 may receive the proposal frequency from the external device 20.

[0046] The parking method setting unit 62 may set (change) the frequency of periodically proposing the second parking control method according to the ratio between the number of times the vehicle 1 has been parked at the target parking position 31 by manual parking and the number of times the vehicle has been parked by parking control of the parking assistance device 10. For example, if the ratio of manual parking is high, the frequency of proposing the second parking control method may be increased, and if the ratio of parking by parking control is high, the frequency of proposing the second parking control method may be decreased.

[0047] The external device 20 may store parking control method data 22 of a plurality of different reference parking control methods. For example, parking control method data 22 of a plurality of different reference parking control methods for controlling the driving of other vehicles may be stored. The external device 20 may store the parking control method data 22 in association with the vehicle type of the other vehicle. The external device 20 may also store the parking control method data 22 in association with the parking mode (hereinafter referred to as "parking mode") when the other vehicle is parking controlled by the reference parking control method. Elements of the "parking mode" may be, for example, the shape of the parking path, the turning position, the vehicle speed near obstacles, and the vehicle speed outside the vicinity of obstacles.

[0048] Furthermore, for example, the external device 20 may store parking control method data 22 for controlling parking of other vehicles in each of a plurality of different parking environments. Here, the "parking environment" may include the vacant space around the target parking position 31 (width of the aisle PW, presence or absence of parked vehicles adjacent to the target parking position 31, location of obstacles), parking style (garage parking, parallel parking, diagonal parking), road surface environment (gravel, asphalt, slope), and environment recognized by the external sensor 14 (road surface pattern, lighting environment, weather). For example, the external device 20 may store the parking environment and the parking control method data 22 in association with each other.

[0049] For example, the parking method setting unit 62 may set the second parking control method by modifying the first parking control method based on the parking control method data 22 stored in the external device 20 in association with a vehicle model, parking mode, and parking environment similar to at least one of the vehicle model of the vehicle 1, the parking mode of the vehicle 1 when the vehicle 1 is manually parked at the target parking position 31, and the parking environment around the target parking position 31. For example, the parking method setting unit 62 may set the second parking control method by modifying the first parking control method based on the parking control method data 22 with the highest similarity between a combination of two or three of the vehicle model, parking mode, and parking environment.

[0050] For example, if the host vehicle 1 is parked at the target parking position 31 using the first parking control method and then manually parked at the target parking position 31, the parking method setting unit 62 may determine the parking mode of the host vehicle 1 based on the detection results of the external sensor 14 and the vehicle sensor 15. For example, when the host vehicle 1 completes manual parking at the target parking position 31, the parking method setting unit 62 may receive parking control method data 22 similar to the determined parking mode of the host vehicle 1 and temporarily store it in the storage device 17b. When the host vehicle 1 approaches the target parking position 31 again from a point away from the target parking position 31 and parks at the target parking position 31, the parking method setting unit 62 may set a second parking control method based on the temporarily stored parking control method data 22 and suggest it to the user. Alternatively, for example, when the host vehicle 1 completes manual parking at the target parking position 31, the parking method setting unit 62 may temporarily store the determined parking mode of the host vehicle 1 in the storage device 17b. When the vehicle 1 approaches the target parking position 31 again from a point away from the target parking position 31 and parks at the target parking position 31, the parking method setting unit 62 may receive parking control method data 22 that is similar to the parking mode of the vehicle 1 that has been temporarily stored, and set a second parking control method based on the received parking control method data 22 and propose it to the user.

[0051] When modifying the first parking control method based on the parking control method data 22, the parking method setting unit 62 may replace the setting values ​​of all of the parking control parameters of the first parking control method with the values ​​of the reference parking control method in the parking control method data 22, or may replace the setting values ​​of some of the parking control parameters. For example, when modifying the first parking control method based on the reference parking control method of a parking mode similar to the parking mode of the host vehicle 1 through manual parking, only parking control parameters that affect similar elements between the elements included in the parking mode of the host vehicle 1 and the elements included in the reference parking control method may be modified. For example, if the "shape of the parking path" among the elements included in the parking mode is similar between the parking mode of the host vehicle 1 and the parking mode of the reference parking control method, only parameters related to the driving path among the elements included in the parking control parameters may be modified.

[0052] The parking method setting unit 62 may also determine the degree of similarity for each element of the parking control parameters of the first parking control method by comparing the vehicle type, parking mode, and parking environment around the target parking position 31 of the host vehicle 1 with the vehicle type, parking mode, and parking environment associated with the parking control method data 22 stored in the external device 20, and modify the value of the element of the parking control parameters of the first parking control method based on the value of the element of the parking control parameter of the parking control method data 22 that has the highest similarity. In this case, if an element of the parking control parameters to be modified is referred to as a "target control parameter element," the parking method setting unit 62 may determine the degree of similarity between the parking mode of the host vehicle 1 and the parking mode of the parking control method data 22 based on the degree of similarity between the parking mode of the host vehicle 1 and the parking mode of the parking control method data 22 of elements included in the parking mode and that are affected by the target control parameter element.

[0053] Alternatively or additionally, the parking method setting unit 62 may set the second parking control method by modifying the first parking control method based on the parking control method data 22 of the reference parking control method most frequently used by users of other vehicles. The parking method setting unit 62 may also set the second parking control method by modifying the first parking control method depending on the number of times parking has been performed using the parking control of the parking assistance device 10. For example, if the number of times parking control has been performed is relatively small, the first parking control method may be modified to perform parking control more slowly. For example, the vehicle speed and upper limit vehicle speed during parking control, the deceleration when stopping, and the acceleration when starting may be reduced. For example, the number of turns may be increased to increase the margin for obstacles. Furthermore, operating instructions for parking assistance by the parking assistance device 10 may be displayed on the HMI 13. On the other hand, if the number of times parking control has been performed is relatively large, the first parking control method may be modified to shorten the time required for parking. For example, the vehicle speed during parking control, the upper limit vehicle speed, the deceleration when stopping, the acceleration when starting may be increased, or the number of turns may be reduced.

[0054] For example, the parking method setting unit 62 may set the second parking control method by modifying the first parking control method according to the frequency of parking performed using the parking control of the parking assistance device 10. For example, if the frequency of parking control is relatively low, the first parking control method may be modified to perform parking control slowly. Furthermore, operation instructions regarding parking assistance by the parking assistance device 10 may be displayed on the HMI 13. On the other hand, if the frequency of parking control is relatively high, the first parking control method may be modified to shorten the time required for parking. For example, the second parking control method may be set by modifying the first parking control method according to the time elapsed since the last time parking control was performed. For example, if the elapsed time is relatively long, the first parking control method may be modified to perform parking control slowly. Furthermore, operation instructions regarding parking assistance by the parking assistance device 10 may be displayed on the HMI 13. On the other hand, if the elapsed time is relatively short, the first parking control method may be modified to shorten the time required for parking.

[0055] Furthermore, for example, the parking method setting unit 62 may modify the first parking control method according to the ratio between the number of times the host vehicle 1 has been parked at the target parking position 31 by manual parking and the number of times the host vehicle 1 has been parked by the parking control of the parking assistance device 10. For example, if the proportion of manual parking is high, the adjustment amount of the parking control parameters may be increased to perform coarse adjustment, and if the proportion of parking by parking control is high, the adjustment amount may be decreased to perform fine adjustment.

[0056] (Effects of the Embodiments) (1) In a parking assistance method for automatically controlling parking to a target parking position, parking control to the target parking position is performed at least once using a first parking control method stored in association with the target parking position as a parking control method for controlling the driving of the host vehicle in the parking control, and a reference parking control method pre-stored in an external device installed outside the host vehicle is received from the external device as a parking control method for controlling the driving of another vehicle other than the host vehicle in the parking control, and after parking the host vehicle at the target parking position using the first parking control method, the first parking control method is modified based on the reference parking control method received from the external device to set a second parking control method, and the second parking control method is presented to the user of the host vehicle. This provides an opportunity to modify the first parking control method, thereby improving user satisfaction with the parking assistance function.

[0057] (2) For example, the second parking control method may be presented to the user of the host vehicle after the initial parking control for parking the host vehicle at the target parking position is completed using the first parking control method, or the second parking control method may be presented to the user of the host vehicle when the user selects to park the host vehicle by manual driving into the target parking position after parking the host vehicle at the target parking position using the first parking control method, or the second parking control method may be presented to the user of the host vehicle when the user completes parking the host vehicle by manual driving into the target parking position after parking the host vehicle at the target parking position using the first parking control method, or a suggestion of the second parking control method may be periodically displayed on a user interface screen that accepts the user's operation to select parking the host vehicle using parking control. This provides an opportunity to modify the first parking control method at an appropriate time.

[0058] (3) A plurality of reference parking control methods may be stored in an external device in association with vehicle types of other vehicles and parking environments in which parking control using the reference parking control methods was performed. The second parking control method may be set by modifying the first parking control method based on reference parking control associated with vehicle types similar to the vehicle's own vehicle and a parking environment similar to the parking environment in which the vehicle is parked. This allows the first parking control method to be modified more appropriately. (4) The second parking control method may be presented to the user of the vehicle more frequently when the user frequently parks the vehicle by manual driving to a target parking position compared to when the user frequently parks the vehicle. This allows the second parking control method to be proposed at an appropriate frequency depending on the user.

[0059] (5) The control parameters of the first parking control method may be modified to set the second parking control method based on the reference parking control method received from an external device. This allows the first parking control method to be modified based on the parking control method used for parking control of vehicles other than the host vehicle. (6) The control parameters may include sensitivity for detecting obstacles around the host vehicle. This eliminates user dissatisfaction with the sensitivity for detecting obstacles around the host vehicle and slowing down or stopping the vehicle during parking control.

[0060] 1...Own vehicle, 10...Parking assistance device, 11...Positioning device, 12...Map database, 13...Human machine interface (HMI), 14...External sensor, 15...Vehicle sensor, 16...Communication device, 17...Controller, 17a...Processor, 17b...Storage device, 18a...Steering actuator, 18b...Accelerator actuator, 18c...Brake actuator

Claims

1. A parking assistance method for performing parking control to automatically drive a host vehicle to a target parking position, the parking assistance method comprising: performing parking control to the target parking position at least once using a first parking control method stored in association with the target parking position as a parking control method for controlling the driving of the host vehicle in the parking control; receiving a reference parking control method pre-stored in an external device provided outside the host vehicle from the external device as a parking control method for controlling the driving of another vehicle other than the host vehicle in the parking control; and after parking the host vehicle at the target parking position using the first parking control method, presenting a second parking control method, which is obtained by modifying the first parking control method based on the reference parking control method received from the external device, to a user of the host vehicle.

2. The parking assistance method according to claim 1, characterized in that the second parking control method is presented to the user of the vehicle after the initial parking control for parking the vehicle at the target parking position using the first parking control method is completed.

3. The parking assistance method described in claim 1, characterized in that after parking the vehicle at the target parking position using the first parking control method, when the user selects to park the vehicle by manual driving at the target parking position, the second parking control method is presented to the user of the vehicle.

4. The parking assistance method described in claim 1, characterized in that after parking the vehicle at the target parking position using the first parking control method, the second parking control method is presented to the user of the vehicle when the user completes parking the vehicle by manual driving at the target parking position.

5. The parking assistance method described in claim 1, characterized in that a proposal for the second parking control method is periodically displayed on a user interface screen that accepts an operation by the user to select parking of the vehicle using the parking control.

6. The parking assistance method described in claim 1, characterized in that a plurality of the reference parking control methods are stored in the external device in association with the vehicle type of the other vehicle and the parking environment in which parking control was performed using the reference parking control method, and the first parking control method is modified to set the second parking control method based on the reference parking control associated with the vehicle type similar to that of the host vehicle and the parking environment similar to the parking environment when parking the host vehicle.

7. The parking assistance method described in claim 1, characterized in that the second parking control method is presented to the user of the vehicle more frequently when the user parks the vehicle by manual driving to the target parking position more frequently than when the user parks the vehicle by manual driving to the target parking position less frequently.

8. The parking assistance method according to claim 1, characterized in that the second parking control method is set by modifying control parameters of the first parking control method based on the reference parking control method received from the external device.

9. The parking assistance method according to claim 8, wherein the control parameters include sensitivity for detecting obstacles around the host vehicle.

10. A parking assistance device that performs parking control to automatically drive a host vehicle to a target parking position, comprising a controller that executes the following processes: a process of executing the parking control to the target parking position at least once using a first parking control method that is stored in association with the target parking position as a parking control method for controlling the driving of the host vehicle in the parking control; a process of receiving a reference parking control method that is pre-stored in an external device provided outside the host vehicle as a parking control method for controlling the driving of another vehicle other than the host vehicle in the parking control, from the external device; and a process of presenting to a user of the host vehicle a second parking control method that is obtained by modifying the first parking control method based on the reference parking control method received from the external device after parking the host vehicle at the target parking position using the first parking control method.

11. A computer program for performing parking control to automatically drive a host vehicle to a target parking position, the computer program causing a controller to execute the following processes: a process of executing the parking control to the target parking position at least once using a first parking control method stored in association with the target parking position as a parking control method for controlling the driving of the host vehicle in the parking control; a process of receiving a reference parking control method pre-stored in an external device provided outside the host vehicle as a parking control method for controlling the driving of another vehicle other than the host vehicle in the parking control, from the external device; and a process of presenting to a user of the host vehicle a second parking control method obtained by modifying the first parking control method based on the reference parking control method received from the external device after parking the host vehicle at the target parking position using the first parking control method.

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