Parking assistance method, parking assistance device, and parking assistance system

Abstract

In this parking assistance method, a controller is caused to implement a first parking assistance function that, on the basis of first parking assistance information including position information of a known object around a host vehicle and information of a candidate parking position stored in association therewith, and position information of an object detected around the host vehicle by a sensor mounted on the host vehicle, sets the candidate parking position corresponding to the position information of the detected object as a target parking position of the host vehicle, and assists parking of the host vehicle to the target parking position. The controller detects the position of another vehicle present around the host vehicle (S2), and when the other vehicle has a second parking assistance function for assisting parking of the other vehicle to a target parking position on the basis of a relative positional relationship of the target parking position of the other vehicle with respect to the other vehicle, generates second parking assistance information representing the relative positional relationship of the target parking position with respect to the other vehicle on the basis of position information of the other vehicle and the first parking assistance information, and transmits the second parking assistance information to the other vehicle (S7, S8).

Description

Parking assistance method, parking assistance device, and parking assistance system

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

[0002] The parking assistance device described in Patent Document 1 extracts feature points from an image captured of an area where the driver wishes to register a parking position, and registers the feature points in association with the parking position, thereby registering the parking position as a registered parking position.When the vehicle is located near the registered parking position, the device detects the feature points to calculate the registered parking position, and performs parking assistance control to park the vehicle at the registered parking position.

[0003] Japanese Patent Application Laid-Open No. 2023-145476

[0004] However, when registered parking position information (information on feature points and parking positions) is shared among multiple vehicles equipped with parking assistance devices, the registered parking position information cannot be used by vehicles equipped with different parking assistance devices. This limits the number of vehicles that can share registered parking position information, limiting the improvement in the convenience of the parking assistance device due to the sharing of registered parking position information. The present invention aims to expand the range of vehicles for which parking assistance is possible using registered parking position information stored in a vehicle equipped with a parking assistance device.

[0005] According to one aspect of the present invention, there is provided a parking assistance method for causing a controller to implement a first parking assistance function that assists in parking the host vehicle at the target parking position, based on first parking assistance information including information on candidate parking positions stored in association with position information of known targets around the host vehicle and position information of targets detected around the host vehicle by a sensor mounted on the host vehicle, by setting the candidate parking position corresponding to the position information of the detected targets as a target parking position of the host vehicle. The controller detects the positions of other vehicles around the host vehicle using a sensor mounted on the host vehicle, determines whether the other vehicles have a second parking assistance function that assists in parking the other vehicles at the target parking position based on a relative positional relationship of the target parking position of the other vehicles with respect to the other vehicles, and if the other vehicles have the second parking assistance function, generates second parking assistance information that indicates the relative positional relationship of the target parking position with respect to the other vehicles based on the position information of the other vehicles detected by the sensor mounted on the host vehicle and the first parking assistance information, and transmits the generated second parking assistance information from the host vehicle to the other vehicles.

[0006] According to the present invention, the range of vehicles that can receive parking assistance can be expanded by utilizing information on registered parking positions stored in a vehicle equipped with a parking assistance device. The objects and advantages of the present invention are realized and attained by using the elements and combinations set forth in the claims. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory and are not intended to limit the invention as defined by the claims.

[0007] 1 is a diagram showing an example of a schematic configuration of a parking assistance system according to an embodiment; (a) and (b) are schematic diagrams illustrating an example of a first parking assistance function; (a) to (c) are schematic diagrams illustrating an example of a process for generating second parking assistance information; and (b) is a flowchart of an example of a parking assistance method according to an embodiment.

[0008] (Configuration) FIG. 1 is a diagram showing an example of the schematic configuration of a parking assistance system according to an embodiment. The parking assistance system 100 includes a first vehicle 1A and a second vehicle 1B equipped with a parking assistance function that assists in parking the vehicles at a target parking position. The first vehicle 1A and the second vehicle 1B are equipped with a first parking assistance device 10A and a second parking assistance device 10B, respectively, that assist in parking the first vehicle 1A and the second vehicle 1B at a target parking position. In the following description, the first vehicle 1A and the second vehicle 1B may be collectively referred to as "vehicle 1," and the first parking assistance device 10A and the second parking assistance device 10B may be collectively referred to as "parking assistance device 10." The first vehicle 1A and the second vehicle 1B are examples of the "host vehicle" and the "other vehicle," respectively, as defined in the claims.

[0009] The parking assistance device 10 executes parking assistance control, which is control that assists the vehicle 1 in traveling along a target traveling route from the current position of the vehicle 1 to a target parking position. For example, the parking assistance control may be automatic driving control that controls the vehicle 1 to travel along the target traveling route of the vehicle 1 to a target parking position. Automatic driving control that controls the vehicle 1 to travel along the target traveling route of the vehicle 1 to a target parking position means control that automatically performs all or part of the traveling of the vehicle 1 along the target traveling route by controlling all or part of the steering angle, driving force, and braking force of the vehicle. Furthermore, for example, the parking assistance control may be control that assists the user in parking the vehicle 1 by displaying the target traveling route and the current position of the vehicle 1 on a display device that is visible to the occupants of the vehicle 1.

[0010] The first parking assistance device 10A of the first vehicle 1A includes an external sensor 11A, a vehicle sensor 12A, a communication device 13A, a positioning device 14A, a controller 15A, and an actuator (ACTR) 16A. The external sensor 11A detects objects within a predetermined distance range from the first vehicle 1A. The external sensor 11A detects the surrounding environment of the first vehicle 1A, such as the relative position of the first vehicle 1A and an object present around the first vehicle 1A, the distance between the first vehicle 1A and the object, and the direction in which the object is present. The external sensor 11A may include, for example, a camera that captures the surrounding environment of the first vehicle 1A. In the following description, the camera included in the external sensor 11A will be simply referred to as the "first camera." The external sensor 11A may include a ranging device such as a laser range finder, radar, or LiDAR (Light Detection and Ranging).

[0011] The vehicle sensor 12A detects various information (vehicle information) about the first vehicle 1A. The vehicle sensor 12A may include, for example, a vehicle speed sensor that detects the traveling speed of the first vehicle 1A, wheel speed sensors that detect the rotational speed of each tire equipped on the first vehicle 1A, a three-axis acceleration sensor (G sensor) that detects the acceleration (including deceleration) of the first vehicle 1A in three axial directions, a steering angle sensor that detects the steering angle, a steering angle sensor that detects the steering angle of the steered wheels, a gyro sensor, and a yaw rate sensor. The communication device 13A provides a communication function between the first parking assistance device 10A and an external device. The communication method used by the communication device 13A may be, for example, wired communication or wireless communication via a public mobile communication network, satellite communication, or vehicle-to-vehicle communication with another vehicle (e.g., the second vehicle 1B). The controller 15A transmits and receives data to and from the second vehicle 1B via the communication device 13A. The positioning device 14A measures the current position and attitude (e.g., the longitudinal direction of the vehicle body) of the first vehicle 1A. Positioning device 14A comprises a Global Navigation Satellite System (GNSS) receiver, such as a Global Positioning System (GPS) receiver.

[0012] The controller 15A is an electronic control unit that performs parking assistance control for the first vehicle 1A. The controller 15A includes a processor 17A and peripheral components such as a storage device 18A. The processor 17A may be, for example, a CPU or an MPU. The storage device 18A may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The functions of the controller 15A described below are realized, for example, by the processor 17A executing a computer program stored in the storage device 18A. The actuator 16A operates the steering device, drive device, and braking device of the first vehicle 1A in response to control signals generated by the controller 15A to generate vehicle behavior of the first vehicle 1A, thereby automatically driving the first vehicle 1A. The actuator 16A includes a steering actuator that operates the steering device, an accelerator opening actuator that operates the drive device, and a brake control actuator that operates the braking device.

[0013] The second parking assistance device 10B of the second vehicle 1B includes an external sensor 11B, a vehicle sensor 12B, a communication device 13B, a positioning device 14B, a controller 15B, and an actuator 16B. The external sensor 11B, the vehicle sensor 12B, the positioning device 14B, and the actuator 16B of the second vehicle 1B may have configurations and functions similar to those of the external sensor 11A, the vehicle sensor 12A, the positioning device 14A, and the actuator 16A of the first vehicle 1A. In the case of the external sensor 11B, the vehicle sensor 12B, the positioning device 14B, and the actuator 16B, in the above-mentioned description of the external sensor 11A, the vehicle sensor 12A, the positioning device 14A, and the actuator 16A, "the first vehicle 1A" should be read as "the second vehicle 1B," "the first camera" should be read as "the second camera," and "the controller 15A" should be read as "the controller 15B."

[0014] The communication device 13B provides a communication function between the second parking assistance device 10B and an external device. The communication method used by the communication device 13B may be, for example, wired communication or wireless communication via a public mobile communication network, satellite communication, or vehicle-to-vehicle communication with another vehicle (e.g., the first vehicle 1A). The controller 15B transmits and receives data to and from the first vehicle 1A via the communication device 13B.

[0015] The controller 15B is an electronic control unit that performs parking assistance control for the second vehicle 1B. The controller 15B includes a processor 17B and peripheral components such as a storage device 18B. The processor 17B may be, for example, a CPU or an MPU. The storage device 18B may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The functions of the controller 15B described below are realized, for example, by the processor 17B executing a computer program stored in the storage device 18B.

[0016] Next, a parking assistance function that assists in parking the vehicle 1 will be described. In this specification, a first parking assistance function and a second parking assistance function will be exemplified. The first parking assistance function is a function that sets a candidate parking position corresponding to the position information of the detected target as a target parking position of the vehicle 1 based on information on known targets around the candidate parking position, information on the candidate parking position, and position information on targets detected around the vehicle 1 by a sensor mounted on the vehicle 1, and assists in parking the vehicle 1 at the target parking position.

[0017] 2(a) and 2(b) are schematic diagrams illustrating an example of the first parking assistance function. When using the first parking assistance function, a candidate parking position 31 where the vehicle 1 should be parked is registered in advance in the parking assistance device 10. Specifically, targets present around the candidate parking position 31 are extracted and stored (registered) in a storage device (e.g., storage device 18A or storage device 18B). In the following description, targets around the candidate parking position 31 stored in the storage device are referred to as "learned targets." In FIG. 2(a), a circle plot is a schematic representation of a learned target. The same applies to FIGS. 4(a) to 4(c) described below. The learned target is an example of a "known target" as defined in the claims.

[0018] For example, when the vehicle 1 is located near the candidate parking position 31 (for example, when the user manually parks the vehicle 1 at the candidate parking position 31), the parking assistance device 10 detects targets around the vehicle 1 using sensors (for example, the external sensor 11A and the external sensor 11B) mounted on the vehicle 1 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 vehicle 1 with a camera. For example, edge points where the brightness of adjacent pixels changes by a predetermined amount or more, such as edges or corners of targets such as road markings, road boundaries, and obstacles, on the captured image obtained by the camera, or points with characteristic shapes (feature points) may be detected as targets.

[0019] The parking assistance device 10 stores first parking assistance information, which is data related to the candidate parking position 31, in a storage device. For example, the first parking assistance information may include data representing the feature amounts of the learned target (hereinafter referred to as "feature amount data") and data representing the relative positional relationship between the candidate parking position 31 and the position of the learned target (hereinafter referred to as "relative position data"). As the relative position data, for example, the relative position of the learned target with respect to the candidate parking position 31 may be stored. For example, the parking assistance device 10 can acquire the position of the learned target detected when the vehicle 1 is parked at the candidate parking position 31 as the relative position of the learned target with respect to the candidate parking position 31. The parking assistance device 10 may store the coordinates of the learned target and the candidate parking position 31 in a coordinate system (hereinafter referred to as "map coordinate system") with a fixed point as the reference point. The parking assistance device 10 may also detect an obstacle O1 around the candidate parking position 31 using a sensor mounted on the vehicle 1. The first parking assistance information may include obstacle data that indicates a relative positional relationship between the candidate parking position 31 and the obstacle O1.

[0020] FIG. 2(b) shows a scene in which the vehicle 1 is parked using the first parking assistance function (hereinafter, this may be referred to as "when parking assistance is being performed"). When parking assistance is being performed, a sensor mounted on the vehicle 1 extracts targets around the vehicle 1. In the following description, targets around the vehicle 1 extracted when parking assistance is being performed are referred to as "surrounding targets." In FIG. 2(b), triangular plots schematically represent surrounding targets. The parking assistance device 10 matches the learned targets with the surrounding targets to associate identical feature points, and calculates the relative position of the candidate parking position 31 with respect to the vehicle 1 based on the relative positional relationship between the surrounding targets detected when parking assistance is being performed and the vehicle 1, and the relative positional relationship between the learned targets associated with the surrounding targets and the candidate parking position 31.

[0021] For example, the parking assistance device 10 calculates the position of the candidate parking position 31 in a coordinate system (hereinafter referred to as the "vehicle coordinate system") based on the current position of the vehicle 1. When the relative position data includes coordinates of the learned targets and the candidate parking position 31 in the map coordinate system, the coordinates of the candidate parking position 31 in the map coordinate system may be converted to coordinates in 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 parking assistance device 10 may calculate the relative position of the obstacle O1 with respect to the vehicle 1 using a similar method. The parking assistance device 10 sets the candidate parking position 31 as a target parking position, and calculates a target parking path 34 from the current position 33 of the vehicle 1 to the target parking position based on the relative position of the candidate parking position 31 with respect to the vehicle 1. The parking assistance device 10 may calculate the target parking path 34 so as to avoid the obstacle O1. The parking assistance device 10 performs parking assistance control for the vehicle 1 based on the calculated target parking path 34.

[0022] On the other hand, the second parking assist function is a function that detects the relative positional relationship of the target parking position with respect to the current position of the vehicle 1 and assists in parking the vehicle 1 at the target parking position based on the detected relative positional relationship. FIG. 3 is a schematic diagram illustrating an example of the second parking assist function. When parking assist control using the second parking assist function is started, the parking assist device 10 uses a sensor mounted on the vehicle 1 to find an available vacant space 41 around the vehicle 1 where parking is possible and sets the space as the target parking position. For example, the parking assist device 10 may find the vacant space 41 based on the detection results of parking frame lines 40 that indicate the parking space. Alternatively, for example, the parking assist device 10 may detect parked vehicles as objects around the vehicle 1 and find the space between the parked vehicles as the vacant space 41.

[0023] The parking assistance device 10 detects the relative position of a target parking position (vacant space) 41 with respect to a current position 33 of the vehicle 1 using a sensor mounted on the vehicle 1, and calculates a target parking path 34 from the current position 33 of the vehicle 1 to the target parking position 41. The parking assistance device 10 may also detect an obstacle O2 around the target parking position 41 using a sensor mounted on the vehicle 1. The parking assistance device 10 may calculate the target parking path 34 so as to avoid the obstacle O2. The parking assistance device 10 performs parking assistance control of the vehicle 1 based on the calculated target parking path 34. Note that the second parking assistance function may be a function (FAP: Full Auto Parking) that automatically controls all of the steering angle, driving force, and braking force of the vehicle 1 so that the vehicle 1 travels along a target travel path from the current position of the vehicle 1 to the target parking position 41, and may also be a function (IPA: Intelligent Parking Assist) in which the user operates the accelerator pedal and brake pedal and the parking assistance device 10 automatically controls only the steering angle.

[0024] 1 , if the first parking assistance device 10A of the first vehicle 1A has a first parking assistance function, and the second parking assistance device 10B of the second vehicle 1B has a third parking assistance function that, based on information on known targets around the candidate parking positions, information on the candidate parking positions, and position information on targets detected around the second vehicle 1B by a sensor mounted on the second vehicle 1B, sets the candidate parking position corresponding to the position information of the detected targets as the target parking position for the second vehicle 1B, and assists the second vehicle 1B in parking at the target parking position, the first parking assistance information stored (registered) in the first parking assistance device 10A can be provided to the second vehicle 1B, thereby assisting the second vehicle 1B in parking at the target parking position by setting the candidate parking position where the first vehicle 1A has previously parked as the target parking position. This improves the convenience of the parking assistance function. In addition, the third parking assistance function provided by the second parking assistance device 10B may be the same function as the first parking assistance function provided by the first parking assistance device 10A, and as long as the basic parts are common, the additional functions added to each may be different.

[0025] However, when the parking assist function of the second vehicle 1B is the second parking assist function, the system of the parking assist function of the first vehicle 1A is different from the system of the parking assist function of the second vehicle 1B, so even if the first parking assist information stored in the first parking assist device 10A is provided to the second vehicle 1B, the information on the target parking position included in the first parking assist information cannot be used by the second parking assist function of the second vehicle 1B. This limits the number of vehicles that can share the first parking assist information, and restricts the improvement in the convenience of the parking assist function that can be achieved by sharing the first parking assist information.

[0026] Therefore, in the parking assistance method of the embodiment, the controller 15A of the first parking assistance device 10A determines whether the second vehicle 1B has the third parking assistance function and whether it has the second parking assistance function. For example, the controller 15A may acquire information on the parking assistance function possessed by the second vehicle 1B from the controller 15B of the second vehicle 1B via the communication devices 13A and 13B. For example, the second vehicle 1B having the second parking assistance function or the third parking assistance function may transmit an identification signal of the second vehicle 1B to the first vehicle 1A when attempting to start parking assistance control. The controller 15A of the first vehicle 1A may determine whether the second vehicle 1B has the third parking assistance function and whether it has the second parking assistance function based on the received identification signal. If the second vehicle 1B does not have the third parking assist function but has the second parking assist function, the controller 15A converts the first parking assist information stored in the first parking assist device 10A into target parking position information that can be used by the second parking assist function of the second vehicle 1B and transmits the converted information to the second vehicle 1B. Specifically, the controller 15A generates second parking assist information that indicates the relative position of the target parking position with respect to the current position of the second vehicle 1B based on the position information of the second vehicle 1B detected by the external sensor 11A and the first parking assist information. The controller 15A transmits the second parking assist information to the second parking assist device 10B of the second vehicle 1B via the communication device 13A.

[0027] The second parking assistance device 10B receives the second parking assistance information via the communication device 13B. The controller 15B calculates a target parking path from the current position of the second vehicle 1B to the target parking position based on the relative positional relationship of the target parking position with respect to the current position of the second vehicle 1B contained in the second parking assistance information. The parking assistance device 10 performs parking assistance control for the second vehicle 1B based on the calculated target parking path.

[0028] FIGS. 4(a) to 4(c) are schematic diagrams illustrating an example of the process for generating second parking assistance information. Here, it is assumed that the first parking assistance information, which is data related to the candidate parking position 31 shown in FIG. 4(a), is stored (registered) in the storage device 18A of the first vehicle 1A. The parking assistance method of this embodiment is executed when both the first vehicle 1A and the second vehicle 1B are located near the candidate parking position 31. For example, the parking assistance method of this embodiment may be executed when both the targets around the candidate parking position 31 and the second vehicle 1B are located within a range detectable by the external sensor 11A of the first vehicle 1A. In FIGS. 4(a) and 4(b), the position of the first vehicle 1A is denoted as "P1," and in FIGS. 4(a) and 4(c), the position of the second vehicle 1B is denoted as "P2."

[0029] The first parking assistance information regarding the candidate parking position 31 may include feature amount data representing feature amounts of the learned target (circle plot) and relative position data representing the relative positional relationship between the candidate parking position 31 and the learned target. For example, the feature amount data may be a partial image including image feature points of the learned target captured by the first camera of the first vehicle 1A. For example, the relative position data may be the relative position coordinates of the learned target in a coordinate system based on the candidate parking position 31, or may include position information of the learned target and the candidate parking position 31 in a map coordinate system based on a fixed point.

[0030] The first parking assistance information may include information specifying the parking direction (i.e., the front-to-rear direction of the vehicle 1 when parked at the candidate parking position 31) in which the vehicle 1 is parked at the candidate parking position 31. If the relative position data is coordinate information on a coordinate system with the candidate parking position 31 as the reference position, the information specifying the parking direction may be omitted by specifying one of the horizontal coordinate axes, the X-axis or the Y-axis, as the parking direction. The first parking assistance information may also include obstacle data indicating the relative positional relationship between the candidate parking position 31 and an obstacle O1 around the candidate parking position 31.

[0031] When generating the second parking assist information from the first parking assist information, the controller 15A uses the external sensor 11A to detect the relative positional relationship between the first vehicle 1A and targets around the first vehicle 1A. In the following description, targets around the first vehicle 1A detected when generating the second parking assist information may be referred to as "detected targets." The controller 15A matches the learned targets with the detected targets to associate identical feature points. Then, based on the relative positional relationship between the detected targets and the first vehicle 1A and the relative positional relationship between the learned targets associated with the detected targets and the candidate parking positions 31, the controller 15A converts the position information of the candidate parking positions 31 in the first parking assist information into coordinates in a coordinate system based on the current position P1 of the first vehicle 1A (hereinafter referred to as the "first vehicle coordinate system").

[0032] For example, the controller 15A may calculate an affine transformation matrix that converts the coordinate positions of the relative position data of the first parking assistance information into coordinate positions on the first vehicle coordinate system based on the relative positional relationship between the detected target and the first vehicle 1A and the relative positional relationship between the learned target associated with the detected target and the candidate parking position 31. The controller 15A may convert the position information of the learned target and the obstacle O1, in addition to the candidate parking position 31, into coordinates on the first vehicle coordinate system. Figure 4(b) shows intermediate map data including the position information of the candidate parking position 31, the learned target, and the obstacle O1 converted into coordinates on the first vehicle coordinate system.

[0033] Next, the controller 15A detects the current position P2 and the longitudinal direction of the second vehicle 1B. For example, the controller 15A may detect the current position P2 and the longitudinal direction of the second vehicle 1B by image recognition processing based on an image of the second vehicle 1B captured by the first camera of the external sensor 11A. The controller 15A may also receive information on the current position and longitudinal direction of the second vehicle 1B measured by the positioning device 14B via the communication devices 13A and 13B. The controller 15A converts the position information of the intermediate map data ( FIG. 4( b) ), which is coordinate information on the first vehicle coordinate system, into coordinates on a coordinate system based on the current position P2 of the second vehicle 1B (hereinafter referred to as the "second vehicle coordinate system") based on the relative positional relationship of the second vehicle 1B with respect to the first vehicle 1A and the relative angle of the longitudinal direction of the second vehicle 1B with respect to the longitudinal direction of the first vehicle 1A.

[0034] FIG. 4(c) shows map data including the position information of the candidate parking position 31, the learned target object, and the obstacle O1 converted into coordinates in the second vehicle coordinate system. The controller 15A transmits the map data in the second vehicle coordinate system ( FIG. 4(c) ) to the second vehicle 1B as second parking assistance information. The second parking assistance information may include the position information of the candidate parking position 31, the learned target object, and the obstacle O1 in the second vehicle coordinate system, as well as feature data of the learned target object. The second parking assistance device 10B receives the second parking assistance information via the communication device 13B. The controller 15B extracts, from the received second parking assistance information, the relative positional relationship of the candidate parking position 31 with respect to the current position of the second vehicle 1B and the direction (parking direction) for parking the vehicle at the candidate parking position 31. The controller 15B sets the candidate parking position 31 as a target parking position and assists the second vehicle 1B in parking the target parking position 31 using the second parking assistance function based on the extracted relative positional relationship and parking direction.

[0035] Specifically, the controller 15B calculates a target parking path from the current position P2 of the second vehicle 1B to the target parking position 31. The controller 15B may calculate the target parking path from the current position P2 to the target parking position 31 while avoiding the obstacle O1. The controller 15B performs parking assist control of the second vehicle 1B based on the calculated target parking path.

[0036] On the other hand, if the parking assist function of the second vehicle 1B is the third parking assist function, the controller 15A of the first parking assist device 10A transmits the first parking assist information to the second vehicle 1B. As a result, when the second vehicle 1B having the second parking assist function or the third parking assist function attempts to start parking assist control, if a vehicle having the first parking assist function (e.g., the first vehicle 1A) is present around the second vehicle 1B, the second vehicle 1B can acquire information regarding the target parking position from the first vehicle 1A and execute automatic parking control. At this time, the controller 15A may determine whether the imaging resolution of the second camera of the vehicle sensor 12B of the second vehicle 1B is the same as the imaging resolution of the first camera of the vehicle sensor 12A of the first vehicle 1A. For example, the controller 15A may acquire information regarding the imaging resolution of the second camera of the second vehicle 1B from the controller 15B of the second vehicle 1B via the communication devices 13A and 13B. When the shooting resolution of the second camera is different from the shooting resolution of the first camera, the controller 15A may change (convert) the resolution of the partial image of the image feature point of the learned target included as feature data in the first parking assistance information to match the shooting resolution of the second camera, and then transmit the first parking assistance information including the changed feature data to the second vehicle 1B.

[0037] The controller 15B uses the third parking assist function to assist the second vehicle 1B in parking at the candidate parking position 31 based on the first parking assist information received from the first vehicle 1A. Specifically, the controller 15B extracts surrounding objects around the second vehicle 1B using the vehicle sensor 12B. The controller 15B matches the learned objects included in the first parking assist information with the surrounding objects and associates identical feature points with each other. The controller 15B calculates the relative position of the candidate parking position 31 with respect to the second vehicle 1B based on the relative positional relationship between the surrounding objects and the second vehicle 1B and the relative positional relationship between the learned objects associated with the surrounding objects and the candidate parking position 31.

[0038] The controller 15B sets the candidate parking position 31 as a target parking position, and calculates a target parking path from the current position of the second vehicle 1B to the target parking position based on the relative position of the candidate parking position 31 with respect to the second vehicle 1B. The controller 15B may calculate the target parking path so as to avoid the obstacle O1 based on information about the obstacle O1 included in the first parking assist information. The controller 15B performs parking assist control for the second vehicle 1B based on the calculated target parking path.

[0039] If the parking assist function of the second vehicle 1B is neither the third parking assist function nor the second parking assist function, or if the second vehicle 1B does not have the parking assist function, the controller 15A generates steering control information and vehicle speed control information for the second vehicle 1B to drive the second vehicle 1B from its current position to the target parking position and stop the second vehicle 1B at the target parking position. For example, the controller 15A may generate map data ( FIG. 4( c) ) in the second vehicle coordinate system in the same manner as when the second vehicle 1B has the second parking assist function. The controller 15A may calculate a target parking path from the current position P2 of the second vehicle 1B to the target parking position 31 based on the map data. The controller 15B may calculate the target parking path so as to avoid the obstacle O1.

[0040] Furthermore, the controller 15A may generate a target vehicle speed profile, which is a target value of the vehicle speed for the second vehicle 1B to travel along the target parking path and stop at the target parking position 31. The controller 15A may generate steering control information and vehicle speed control information for causing the second vehicle 1B to travel along the target parking path, based on the target parking path and the target vehicle speed profile. The controller 15A may transmit the generated steering control information and vehicle speed control information to the second vehicle 1B. The controller 15B of the second vehicle 1B controls the actuator 16B based on the steering control information and vehicle speed control information received from the first vehicle 1A, causing the second vehicle 1B to travel to the target parking position 31 and stop at the target parking position 31.

[0041] (Operation) Figure 5 is a flowchart of an example of the parking assistance method of the embodiment. In step S1, the controller 15A of the first vehicle 1A determines whether the first vehicle 1A is located near a candidate parking position. If the first vehicle 1A is not located near a candidate parking position (step S1: N), the process ends. If the first vehicle 1A is located near a candidate parking position (step S1: Y), the process proceeds to step S2.

[0042] In step S2, the controller 15A determines whether or not the second vehicle 1B is located near the first vehicle 1A. If the second vehicle 1B is not located near the first vehicle 1A (step S2: N), the process ends. If the second vehicle 1B is located near the first vehicle 1A (step S2: Y), the process proceeds to step S3. In step S3, the controller 15A determines whether or not the second vehicle 1B has a third parking assist function. If the second vehicle 1B does not have the third parking assist function (step S3: N), the process proceeds to step S6. If the second vehicle 1B has the third parking assist function (step S3: Y), the process proceeds to step S4.

[0043] In step S4, the controller 15A transmits the first parking assist information stored in the storage device 18A to the second vehicle 1B. In step S5, the controller 15B of the second vehicle 1B executes parking assist control of the second vehicle 1B using the third parking assist function based on the first parking assist information received from the first vehicle 1A. The process then ends. In step S6, the controller 15A determines whether the second vehicle 1B has the second parking assist function. If the second vehicle 1B does not have the second parking assist function (step S6: N), the process proceeds to step S10. If the second vehicle 1B has the second parking assist function (step S6: Y), the process proceeds to step S7.

[0044] In step S7, controller 15A generates second parking assist information based on the first parking assist information stored in storage device 18A. In step S8, controller 15A transmits the second parking assist information to second vehicle 1B. In step S9, controller 15B executes parking assist control of second vehicle 1B using the second parking assist function based on the second parking assist information received from first vehicle 1A. The process then ends.

[0045] In step S10, the controller 15A generates steering control information and vehicle speed control information for driving the second vehicle 1B to the target parking position and stopping the second vehicle 1B at the target parking position, based on the first parking assist information stored in the storage device 18A. In step S11, the controller 15A transmits the steering control information and vehicle speed control information to the second vehicle 1B. In step S12, the controller 15B controls the driving of the second vehicle 1B based on the received steering control information and vehicle speed control information, and drives the second vehicle 1B to the target parking position and stops it there. The processing then ends.

[0046] (Effects of the Embodiment) (1) Based on first parking assistance information including information on candidate parking positions stored in association with position information of known targets around the host vehicle and position information of targets detected around the host vehicle by a sensor mounted on the host vehicle, the controller sets the candidate parking position corresponding to the position information of the detected targets as the target parking position of the host vehicle, thereby realizing a first parking assistance function that assists in parking the host vehicle at the target parking position. The controller detects the positions of other vehicles around the host vehicle using a sensor mounted on the host vehicle, determines whether the other vehicles have a second parking assistance function that assists in parking the other vehicles at the target parking position based on the relative positional relationship of the target parking position of the other vehicles with respect to the other vehicles, and if the other vehicles have the second parking assistance function, generates second parking assistance information that indicates the relative positional relationship of the target parking position with respect to the other vehicles based on the position information of the other vehicles detected by the sensor mounted on the host vehicle and the first parking assistance information, and transmits the generated second parking assistance information from the host vehicle to the other vehicles.

[0047] Therefore, even if the parking assist function of the other vehicle is the second parking assist function, the parking of the other vehicle can be assisted by using the first parking assist information stored in the own vehicle, which has the first parking assist function. As a result, the range of vehicles for which parking assistance is possible using the first parking assist information stored in the own vehicle can be expanded.

[0048] (2) The controller may set the candidate parking position corresponding to the position information of the detected target as the target parking position of the other vehicle based on third parking assistance information including information on known targets around the other vehicle and information on candidate parking positions stored in association with information on known targets around the other vehicle, and position information on targets detected around the other vehicle by a sensor mounted on the other vehicle, and determine whether the other vehicle has a third parking assistance function that assists the other vehicle in parking at the target parking position. If the other vehicle does not have the third parking assistance function but has the second parking assistance function, the controller may transmit the second parking assistance information from the host vehicle to the other vehicle. As a result, even if the other vehicle has the second parking assistance function, the controller can assist the other vehicle in parking at the target parking position using the first parking assistance information stored in the host vehicle. As a result, the range of vehicles for which parking assistance is possible using the first parking assistance information stored in the host vehicle can be expanded. (3) If the other vehicle has the third parking assistance function, the controller may transmit the first parking assistance information from the host vehicle to the other vehicle. As a result, the range of vehicles for which parking assistance is possible can be expanded by utilizing the first parking assistance information stored in the host vehicle.

[0049] (4) When the image capturing resolution of a first camera mounted on the host vehicle as a sensor for detecting targets around the host vehicle differs from the image capturing resolution of a second camera mounted on the other vehicle as a sensor for detecting targets around the other vehicle, the controller may change the first parking assistance information transmitted to the other vehicle so that the resolution of image feature points of known targets matches the image capturing resolution of the second camera. This improves the matching accuracy between learned targets having image feature points extracted from images captured by the first camera of the host vehicle and surrounding targets having image feature points extracted from images captured by the second camera of the other vehicle when providing parking assistance to the other vehicle.

[0050] (5) When the other vehicle does not have either the second parking assist function or the third parking assist function, the controller may generate steering control information and vehicle speed control information for the other vehicle to drive to the target parking position and stop the other vehicle at the target parking position based on the position information of the other vehicle detected by the own vehicle and the information of the candidate parking position, and transmit the information from the own vehicle to the other vehicle. In this way, even if the parking assist function of the other vehicle is not the third parking assist function or the second parking assist function, or even if the other vehicle does not have a parking assist function, the controller can assist the other vehicle in parking by using the first parking assist information stored in the own vehicle which has the first parking assist function.

[0051] All examples and conditional terms described herein are intended for educational purposes to aid the reader in understanding the present invention and the concepts provided by the inventor for the advancement of technology, and should be construed without limitation to the specifically described examples and conditions above, and the configuration of examples herein for illustrating the advantages and disadvantages of the present invention. Although the embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present invention.

[0052] DESCRIPTION OF SYMBOLS 1A...first vehicle, 1B...second vehicle, 10A...first parking assistance device, 10B...second parking assistance device, 11A, 11B...external sensor, 12A, 12B...vehicle sensor, 13A, 13B...communication device, 14A, 14B...positioning device, 15A, 15B...controller, 16A, 16B...actuator (ACTR), 17A, 17B...processor, 18A, 18B...storage device, 100...parking assistance system

Claims

1. A parking assistance method in which, based on first parking assistance information including information on candidate parking positions stored in association with position information of known targets around the host vehicle and position information of targets detected around the host vehicle by a sensor mounted on the host vehicle, a candidate parking position corresponding to the detected position information of the target targets is set as a target parking position of the host vehicle, and a controller is caused to realize a first parking assistance function that assists in parking the host vehicle at the target parking position, wherein the controller: detects the position of another vehicle present around the host vehicle by a sensor mounted on the host vehicle; determines whether the other vehicle has a second parking assistance function that assists in parking the other vehicle at the target parking position based on a relative positional relationship of the target parking position of the other vehicle with respect to the other vehicle; if the other vehicle has the second parking assistance function, generates second parking assistance information that indicates the relative positional relationship of the target parking position with respect to the other vehicle based on the positional information of the other vehicle detected by the sensor mounted on the host vehicle and the first parking assistance information; and transmits the generated second parking assistance information from the host vehicle to the other vehicle. A parking assistance method comprising:

2. Based on third parking assistance information including information on candidate parking positions stored in association with information on known targets around the other vehicle and position information of targets detected around the other vehicle by a sensor mounted on the other vehicle, the candidate parking position corresponding to the position information of the detected targets is set as the target parking position of the other vehicle, and it is determined whether the other vehicle has a third parking assistance function that assists the other vehicle in parking at the target parking position, and if the other vehicle does not have the third parking assistance function but has the second parking assistance function, the second parking assistance information is transmitted from the host vehicle to the other vehicle.

3. The parking assistance method according to claim 2, characterized in that the first parking assistance information is transmitted from the subject vehicle to the other vehicle when the other vehicle has the third parking assistance function.

4. The parking assistance method described in claim 3, characterized in that when the shooting resolution of a first camera mounted on the host vehicle as a sensor for detecting targets around the host vehicle differs from the shooting resolution of a second camera mounted on the other vehicle as a sensor for detecting targets around the other vehicle, the first parking assistance information transmitted to the other vehicle is changed so that the resolution of the image feature points of the known target matches the shooting resolution of the second camera.

5. A parking assistance method as described in any one of claims 2 to 4, characterized in that, when the other vehicle does not have either the second parking assistance function or the third parking assistance function, steering control information and vehicle speed control information for the other vehicle are generated based on the position information of the other vehicle detected by the host vehicle and information on the candidate parking position, in order to drive the other vehicle to the target parking position and stop the other vehicle at the target parking position, and the information is transmitted from the host vehicle to the other vehicle.

6. A parking assistance device having a first parking assistance function that sets a candidate parking position corresponding to the position information of the detected target object as a target parking position of the host vehicle based on first parking assistance information including information on candidate parking positions stored in association with position information of known targets around the host vehicle and position information of targets detected around the host vehicle by a sensor mounted on the host vehicle, and assists in parking the host vehicle at the target parking position, the device comprising: a process of detecting the position of another vehicle present around the host vehicle by a sensor mounted on the host vehicle; a process of determining whether the other vehicle has a second parking assistance function that assists in parking the other vehicle at the target parking position based on the relative positional relationship of the target parking position of the other vehicle with respect to the other vehicle; if the other vehicle has the second parking assistance function, a process of generating second parking assistance information that indicates the relative positional relationship of the target parking position with respect to the other vehicle based on the positional information of the other vehicle detected by the sensor mounted on the host vehicle and the first parking assistance information; and a process of transmitting the generated second parking assistance information from the host vehicle to the other vehicle. A parking assistance device comprising: a controller that executes the above.

7. A parking assistance system comprising: a first parking assistance device having a first parking assistance function that, based on first parking assistance information including position information of known targets around a first vehicle and information on candidate parking positions stored in association with position information of the targets detected around the first vehicle by a sensor mounted on the first vehicle, sets a candidate parking position corresponding to the position information of the detected targets as a target parking position of the first vehicle, and assists parking of the first vehicle at the target parking position; and a second parking assistance device having a second parking assistance function that assists parking of the second vehicle at the target parking position based on a relative positional relationship of the target parking position of the second vehicle with respect to the second vehicle, wherein the first parking assistance device, when the second vehicle is equipped with the second parking assistance device, acquires positional information of the second vehicle with respect to the first vehicle, generates second parking assistance information representing the relative positional relationship of the target parking position with respect to the second vehicle based on the position information of the second vehicle and the first parking assistance information, and transmits the generated second parking assistance information from the first vehicle to the second vehicle; and the second parking assistance device receiving the second parking assistance information from the first parking assistance device, and assisting the second vehicle in parking at the target parking position based on a relative positional relationship of the target parking position with respect to the second vehicle in the received second parking assistance information.

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