Parking assistance method and parking assistance device

Abstract

In a parking assistance method for assisting a host vehicle in parking to a target parking position, when a parking position candidate which is a candidate for the target parking position and exists around the host vehicle cannot be detected (S1: N), when a reason for which the parking position candidate cannot be detected is an environmental reason which is a reason depending on the environment of the host vehicle, the host vehicle is parked to the target parking position. When the condition that the parking position candidate is a reason dependent on a user is detected, the environment reason is displayed on a display device (S5), and when the condition that the parking position candidate is a reason dependent on the user is not detected, the user reason is displayed on the display device (S4).

Description

Technical Field

[0001] The invention relates to a parking assistance method and a parking assistance device. Background Art

[0002] Patent Document 1 listed below describes that, during automatic parking by a parking assist system, an alarm is output when it is determined that a parking operation should be prohibited.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: (Japanese) Patent Application Publication No. 2021-095113 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the parking assist system of Patent Document 1, if the target parking position for parking the vehicle cannot be detected, the user may not know the reason for the failure and may be unable to cope with the failure.

[0008] An object of the present invention is to enable a user to easily cope with a situation where a target parking position cannot be detected during parking assistance for assisting a vehicle in parking the target parking position.

[0009] Technical solutions to solve problems

[0010] According to one aspect of the present invention, a parking assistance method for assisting a vehicle in parking at a target parking location is provided. In the parking assistance method, if a parking location candidate existing around the vehicle that is a candidate for the target parking location cannot be detected, and if the reason for not being able to detect the parking location candidate is a factor dependent on the environment of the vehicle, i.e., an environmental factor, the environmental factor is displayed on a display device. If the reason for not being able to detect the parking location candidate is a factor dependent on the user, i.e., a user factor, the user factor is displayed on the display device.

[0011] Effects of the Invention

[0012] According to the present invention, a user can easily cope with a situation where a target parking position cannot be detected during parking assistance for assisting a host vehicle in parking the target parking position. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing a schematic configuration example of a parking assist device according to an embodiment.

[0014] Figure 2 (a) and (b) are schematic diagrams for explaining parking assist control in the first assist mode.

[0015] Figure 3 This is a schematic diagram for explaining parking assist control in the second assist mode.

[0016] Figure 4 This is a diagram showing an example of a successful detection screen.

[0017] Figure 5 This is a diagram showing an example of the first help screen.

[0018] Figure 6 This is a diagram showing an example of the second help screen.

[0019] Figure 7 This is a flowchart of the driving assistance method according to the first embodiment.

[0020] Figure 8 yes Figure 1 A block diagram showing an example of the functional configuration of a controller.

[0021] Figure 9 This is a diagram showing an example of a search screen.

[0022] Figure 10 This is a diagram showing an example of a detection failure screen.

[0023] Figure 11 (a) and (b) are explanatory diagrams of examples of user reasons in the first assistance mode.

[0024] Figure 12 This is a flowchart of the driving assistance method according to the second embodiment. DETAILED DESCRIPTION

[0025] (First embodiment)

[0026] (constitute)

[0027] Figure 1This figure shows a schematic configuration example of a parking assistance device according to an embodiment. A vehicle 1 is equipped with a parking assistance device 10 that assists the vehicle 1 in parking at a target parking position. The parking assistance device 10 assists the vehicle 1 in traveling along a target parking path from its current position to the target parking position. For example, automated driving may be performed to control the vehicle 1 to travel along its target parking path to the target parking position. Automated driving to control the vehicle 1 to travel along its target parking path to the target parking position refers to controlling all or part of the steering angle, driving force, and braking force of the vehicle 1 to automatically control all or part of the vehicle 1's travel along the target parking path. Alternatively, parking assistance may be provided by displaying the target parking path and the current position of the vehicle 1 on a display device that is visually visible to a user of the vehicle 1 (e.g., a driver or other passenger).

[0028] The positioning device 11 measures the current position of the vehicle 1. The positioning device 11 includes, for example, a Global Positioning System (GNSS) receiver. A map database (map DB) 12 stores map data. The map data stored in the map DB 12 may be, for example, navigation map data or high-precision map data suitable for autonomous driving.

[0029] The human-machine interface (HMI) 13 is an interface device that transmits and receives information between the parking assistance system 10 and the user. For example, the HMI 13 may include a user-visible display device as an interface for presenting visual information to the user. Alternatively, the HMI 13 may include a speaker or buzzer as an interface for presenting auditory information to the user. Furthermore, the HMI 13 may include an interface (such as a touch panel, buttons, switches, levers, dials, or keyboard) for receiving user input.

[0030] The shift switch (shift SW) 14 is a switch used by the driver or the parking assist device 10 to switch the shift position of the host vehicle 1 .

[0031] The external sensor 15 detects objects within a specified distance range from the vehicle 1. The external sensor 15 detects the surrounding environment of the vehicle 1, such as the relative position of objects around the vehicle 1 and the vehicle 1, the distance between the vehicle 1 and the object, and the direction in which the object exists. The external sensor 15 may include, for example, a camera that captures the surrounding environment of the vehicle 1. The external sensor 15 may also include a laser rangefinder or a ranging device such as radar, LiDAR (Light Detection and Ranging), or sonar. The vehicle sensor 16 detects various information (vehicle information) about the vehicle 1. For example, the vehicle sensor 16 may include a vehicle speed sensor that detects the driving speed of the vehicle 1, a three-axis acceleration sensor that detects the acceleration (including deceleration) of the vehicle 1 in three axes, and a sensor that detects the steering angle of the handle or the steering angle of the steering wheel.

[0032] The parking switch (parking SW) 17 is a switch for activating parking assist control by the parking assist device 10 .

[0033] The mode changeover switch (mode changeover SW) 18 is a switch for changing the control mode of the parking assist control performed by the parking assist device 10 .

[0034] The controller 19 is an electronic control unit that performs parking assist control for the vehicle 1. The controller 19 includes peripheral components such as a processor 19a and a storage device 19b. The processor 19a may be, for example, a CPU or an MPU. The storage device 19b may include a semiconductor memory device, a magnetic storage device, an optical storage device, or the like. The functions of the controller 19 described below are implemented, for example, by the processor 19a executing a computer program stored in the storage device 19b.

[0035] The parking brake 20 generates friction braking force on the wheels of the host vehicle 1 in response to a user operation or a control signal from the controller 19 .

[0036] The steering actuator 21a controls the steering direction and amount of the steering mechanism of the vehicle 1 based on a control signal from the controller 19. The accelerator actuator 21b controls the throttle position of the engine or a drive device serving as a drive motor based on a control signal from the controller 19. The brake actuator 21c activates the brake device based on a control signal from the controller 19.

[0037] Next, the parking assist control performed by the controller 19 will be described. The controller 19 can execute parking assist control that detects parking position candidates existing around the host vehicle 1 and sets the detected parking position candidate as a target parking position to assist parking.

[0038] For example, the controller 19 may detect parking position candidates existing around the host vehicle 1 from the target parking positions pre-registered in the storage device 19b. In the following description, the control mode of the parking assist control in which parking is assisted by detecting parking position candidates from the pre-registered target parking positions may be referred to as the "first assist mode."

[0039] Alternatively, for example, the controller 19 may detect free spaces such as parking frames around the host vehicle 1 as parking position candidates, rather than using a pre-registered target parking position. In the following description, the parking assist control mode that assists parking by detecting free spaces around the host vehicle 1 as parking position candidates, rather than using a pre-registered target parking position, may be referred to as a "second assist mode."

[0040] Figure 2 (a) and Figure 2 (b) is a schematic diagram illustrating the parking assist control of the first assist mode. When utilizing the parking assist control of the first assist mode, the target parking position 31 at which the vehicle 1 is to be parked is pre-registered in the parking assist device 10. Specifically, the target objects existing around the target parking position 31 are extracted and pre-stored (registered) in the storage device 19b. In the following description, the target objects around the target parking position 31 stored in the storage device 19b are referred to as "learned target objects." Figure 2 In (a), a circle schematically represents a learning completion target object. When registering the target parking position 31 in the parking assist device 10 , for example, the user performs an operation to instruct registration of the target parking position 31 (hereinafter sometimes referred to as a “registration operation”).

[0041] For example, when the vehicle 1 is near the target parking location 31 (e.g., when the user manually parks the vehicle 1 at the target parking location 31), the controller 19 uses the external sensor 15 to detect objects around the vehicle 1 and stores them as learned objects. For example, objects can be detected from an image of the surrounding area of ​​the vehicle 1 captured by a camera. For example, edge points or corners of objects such as road markings, road boundaries, and obstacles in the camera image, where the brightness of adjacent pixels changes by more than a specified amount, or points with characteristic shapes (feature points) can be detected as objects.

[0042] Controller 19 stores learned target data related to the learned target in storage device 19b. For example, the learned target data may include data representing characteristic quantities of the learned target (hereinafter referred to as "characteristic quantity data") and data regarding the relative positional relationship between target parking position 31 and the learned target (hereinafter referred to as "relative position data").

[0043] For example, the relative position of the learned target object relative to the target parking position 31 may be stored as relative position data. For example, the controller 19 may obtain the position of the learned target object detected when the vehicle 1 is parked at the target parking position 31 as the relative position of the learned target object relative to the target parking position 31. Alternatively, the coordinates of the learned target object and the target parking position 31 in a coordinate system (hereinafter referred to as the "map coordinate system") based on a fixed location may be stored.

[0044] Figure 2 (b) is an illustrative diagram of an example of a process for implementing parking assistance. The controller 19 initiates parking assistance control for the vehicle 1 upon a user operation (hereinafter sometimes referred to as a "start operation") instructing the vehicle 1 to initiate parking assistance control. For example, the start operation may be a user operation of the parking switch 17. Alternatively, the controller 19 may automatically initiate parking assistance control when the vehicle 1 approaches a registered target parking position 31. Alternatively, the parking assistance device 10 may be switchable between an automatic start mode and a manual start mode. In the automatic start mode, parking assistance control automatically initiates when the vehicle 1 approaches a registered target parking position 31. In the manual start mode, parking assistance control is not automatically initiated even when the vehicle 1 approaches a registered target parking position 31.

[0045] When the parking assist control is started, the controller 19 uses the external sensor 15 to extract objects around the host vehicle 1. In the following description, the objects around the host vehicle 1 extracted when the parking assist is performed are referred to as "surrounding objects". Figure 2 In (b), the triangles represent surrounding objects. The controller 19 matches the learned objects with the surrounding objects, associating common feature points. This allows the controller 19 to detect the registered target parking position 31 as a candidate parking position. The controller 19 calculates the relative position of the vehicle 1 relative to the target parking position 31 based on the relative positional relationship between the surrounding objects detected during parking assistance and the host vehicle 1, and the relative positional relationship between the learned objects associated with the surrounding objects and the target parking position 31.

[0046] For example, controller 19 calculates the position of target parking position 31 in a coordinate system based on the current position of host vehicle 1 (hereinafter referred to as the "vehicle coordinate system"). It should be noted that if the map coordinate system coordinates of learned objects and target parking position 31 are stored in storage device 19b, the coordinates of target parking position 31 in the map coordinate system can be converted to coordinates in the vehicle coordinate system based on the positions of surrounding objects detected during parking assistance and the positions of the learned objects in the map coordinate system. Alternatively, the position of host vehicle 1 in the map coordinate system can be determined based on the positions of surrounding objects detected during parking assistance and the positions of the learned objects in the map coordinate system, and the relative position of host vehicle 1 with respect to target parking position 31 can be calculated based on the difference between the coordinates of host vehicle 1 in the map coordinate system and the coordinates of target parking position 31.

[0047] Figure 3 This diagram illustrates parking assist control in the second assist mode. When the user initiates a start operation to activate parking assist control, controller 19 initiates parking assistance for vehicle 1. Upon activation of parking assist control in the second assist mode, controller 19 detects available parking spaces 31a-31d around vehicle 1 as potential parking positions based on the detection results of white lines 35 or objects around vehicle 1 by external sensors 15. The controller then sets any of these spaces as the target parking position.

[0048] For example, the controller 19 may detect available parking spaces around the host vehicle 1 as parking position candidates based on the detection result of the parking frame line 35 representing the parking space. Alternatively, for example, the controller 19 may detect a parked vehicle as an object around the host vehicle 1 and the space between the parked vehicles as a parking position candidate.

[0049] If the parking position candidate can be detected as described above, the controller 19 displays a detection success screen on the display device of the HMI 13 to notify the user that the parking position candidate has been successfully detected. Figure 4 This is a schematic diagram of an example of a successful detection screen. For example, successful detection screen 40a includes a captured image 41 generated by capturing the surroundings of the vehicle 1, an overhead image 42 generated by converting the captured image of the surroundings of the vehicle 1, a message display area 43 for displaying notifications such as visual messages, a parking start button 44, and an end button 45.

[0050] A visual message or other notification notifying the user that a candidate parking location has been detected is displayed in message display area 43 of detection success screen 40a. Furthermore, if the user operates parking start button 44 or end button 45 displayed on the display device, the touch panel provided on the display device detects these operations. If parking start button 44 is operated, controller 19 sets the candidate parking location as target parking location 31 and calculates target parking path 34 from current position 33 of host vehicle 1 to target parking location 31. Based on calculated target parking path 34, controller 19 implements parking assistance control for host vehicle 1.

[0051] If the end button 45 is operated, the controller 19 terminates the parking assist control. Figure 9 and Figure 10 The same applies to the case where the end button 45 of the search screen 40d and the detection failure screen 40e described later is operated.

[0052] On the other hand, when the parking position candidate cannot be detected, the controller 19 determines whether the reason for the failure to detect the parking position candidate is a user factor that depends on the user or an environmental factor that depends on the environment of the host vehicle 1 .

[0053] If the reason why the parking position candidate cannot be detected is due to user error, the controller 19 displays a first help screen on the display device of the HMI 13 to inform the user that the error is due to user error.

[0054] Figure 5 This is a schematic diagram of an example of a first help screen. For example, first help screen 40b includes an overhead image 42, a user reason display area 46 that displays the user reason, and a return button 47. When the user presses return button 47, the touch panel provided on the display device detects the operation, and controller 19 stops displaying first help screen 40b.

[0055] If the reason why the parking position candidate cannot be detected is due to environmental factors, the controller 19 displays a second help screen on the display device of the HMI 13 to inform the user that it is due to environmental factors.

[0056] Figure 6 4 is a schematic diagram of an example of a second help screen. For example, the second help screen 40c includes an overhead image 42, an environmental factor display area 48 that displays environmental factors, and a return button 47. If the user presses the return button 47, the controller 19 stops displaying the second help screen 40c.

[0057] (action)

[0058] Figure 7This is a flowchart of the driving assistance method according to the first embodiment. In step S1, the controller 19 determines whether a parking position candidate can be detected. If a parking position candidate can be detected (step S1: Y), the process proceeds to step S2. If a parking position candidate cannot be detected (step S1: N), the process proceeds to step S3. In step S2, the controller 19 displays a detection success screen 40a on the display device. In step S3, the controller 19 determines whether the failure to detect a parking position candidate is due to user error. If the failure to detect a parking position candidate is due to user error (step S3: Y), the process proceeds to step S4. If the failure to detect a parking position candidate is due to environmental error (step S3: N), the process proceeds to step S5. In step S4, the controller 19 displays a first help screen 40b on the display device. In step S5, the controller 19 displays a second help screen 40c on the display device.

[0059] (Second embodiment)

[0060] Figure 8 This is a block diagram showing an example of the functional configuration of the controller 19. Upon detecting a user operation to register the target parking position 31, the HMI control unit 50 outputs a map generation command to the map generation unit 55 to store the learned target object data in the storage device 19b. Furthermore, upon detecting a user operation to start parking assist control, the HMI control unit 50 outputs a control start command to the parking assist control unit 51 to initiate parking assist control toward the target parking position.

[0061] The image conversion unit 52 converts the image captured by the camera into a bird's-eye view image as viewed from a virtual viewpoint directly above the host vehicle 1. The image conversion unit 52 generates an image of the surrounding area of ​​the host vehicle 1, i.e., a surrounding image, by converting the captured image into a bird's-eye view image at predetermined intervals and accumulating the converted bird's-eye view images along the travel path of the host vehicle 1.

[0062] The own position calculation unit 53 calculates the current position of the host vehicle 1 on the map coordinate system as the own position by using an odometry method (eg, dead reckoning) based on vehicle information output from the vehicle sensor 16 .

[0063] The object detection unit 54 detects objects based on the surrounding image output from the image conversion unit 52. The object detection unit 54 can detect the positions of the object's characteristic points and their image features as the object. The object detection unit 54 outputs the detected positions of the characteristic points and image features as object data to the map generation unit 55 and the target parking position detection unit 57. Furthermore, the vehicle's own position, acquired by the own position calculation unit 53 in synchronization with the detection of the object, is output to the map generation unit 55 and the target parking position detection unit 57.

[0064] Upon receiving a map generation command from the HMI control unit 50 (i.e., upon registering the target parking position 31), the map generation unit 55 generates learned target object data and stores it as map data 56 in the storage device 19b. For example, the map generation unit 55 receives the target object data and the vehicle's own position in a map coordinate system synchronized with the target object data from the target object detection unit 54. The map generation unit 55 obtains position information of the target parking position 31 in the map coordinate system. For example, when the vehicle 1 is located at the target parking position 31, the vehicle's own position calculated by the vehicle position calculation unit 53 can be obtained as the position information of the target parking position 31. The map generation unit 55 generates relative position data based on the positions of feature points included in the target object data, the synchronized position information of the vehicle 1, and the position information of the target parking position 31. The map generation unit 55 obtains feature value data based on the target object data output by the target object detection unit 54. The learned target object data, including these relative position data and feature value data, is stored as map data 56 in the storage device 19b.

[0065] When the parking assistance device 10 is set to the automatic start mode, the parking assistance control unit 51 determines whether the current position of the host vehicle 1 is near the registered target parking position 31. If the current position of the host vehicle 1 is near the registered target parking position 31, the parking assistance control unit 51 starts, causing the parking assistance device 10 to operate in the first assistance mode. On the other hand, when the parking assistance device 10 is set to the manual start mode, upon receiving a control start command from the HMI control unit 50, the parking assistance control unit 51 determines whether the current position of the host vehicle 1 is near the registered target parking position 31. If the current position of the host vehicle 1 is near the registered target parking position 31, the parking assistance control unit 51 causes the parking assistance device 10 to operate in the first assistance mode. If the current position of the host vehicle 1 is not near the registered target parking position 31, the parking assistance control unit 51 causes the parking assistance device 10 to operate in the second assistance mode.

[0066] Once parking assist control is initiated, parking assist control unit 51 determines whether predetermined system conditions for executing parking assist control are met. If the system conditions are met, a parking position calculation command is output to target parking position detection unit 57. If the system conditions are not met, no parking position calculation command is output to target parking position detection unit 57. Therefore, target parking position detection unit 57 does not detect a candidate parking position. In other words, target parking position detection unit 57 does not determine whether a candidate parking position can be detected. System conditions may include, for example, the shift position not being in park or the user wearing a seatbelt.

[0067] If a parking position calculation instruction is received, the target parking position detection unit 57 receives the target object data output from the target object detection unit 54 as target object data of surrounding targets in the case of parking assist control in the first assist mode, and receives the own position of the vehicle 1 in the map coordinate system synchronously therewith.

[0068] The target parking position detection unit 57 detects the registered target parking position 31 as a parking position candidate by matching the learned object with surrounding objects, establishing a correspondence between objects sharing the same feature points. Specifically, the detection of the registered target parking position 31 is determined based on whether the matching between the learned object and the surrounding objects is successful. If the matching is successful (i.e., the target parking position 31 is detected), the target parking position detection unit 57 calculates the relative position of the host vehicle 1 with respect to the target parking position 31 based on the relative positional relationships between the surrounding objects and the host vehicle 1 and the relative positional relationship between the learned object associated with the surrounding objects and the target parking position 31.

[0069] In the parking assist control of the second assist mode, the target parking position detection unit 57 determines whether there is a parking space around the host vehicle 1 (i.e., determines whether the target parking position 31 can be detected) based on the detection results of the white lines around the host vehicle 1 or objects around the host vehicle 1 (e.g., parked vehicles) by the external sensor 15. The target parking position detection unit 57 detects the parking space around the host vehicle 1 as a parking position candidate.

[0070] The parking assist control unit 51 sets the detected parking position candidate as the target parking position 31. The target trajectory generation unit 59 calculates a target parking path from the current position of the host vehicle 1 in the vehicle coordinate system to the target parking position 31. The target trajectory generation unit 59 calculates a target speed curve, which is a target value for the vehicle speed of the host vehicle 1 along the target parking path. The steering control unit 60 controls the steering actuator 21a to move the host vehicle 1 along the target parking path. The vehicle speed control unit 61 controls the accelerator actuator 21b and the brake actuator 21c to change the vehicle speed of the host vehicle 1 according to the target speed curve. When the host vehicle 1 reaches the target parking position 31 and parking assist control is completed, the parking assist control unit 51 applies the parking brake 20 to shift the gear position to the parking position.

[0071] While the target parking position detection unit 57 is attempting to detect a parking position candidate (i.e., while attempting to match the learned target object with surrounding objects), the HMI control unit 50 displays a search screen on the display device of the HMI 13 to inform the user that the parking assistance device 10 is attempting to detect a parking position candidate.

[0072] Figure 9 This is a schematic diagram of an example search screen. For example, search screen 40d includes a captured image 41, an overhead image 42, a message display area 43, and an end button 45. Message display area 43 may display a visual message or other notification informing the user that the parking assistance system 10 is attempting to detect a parking location candidate.

[0073] Furthermore, if the target parking position detection unit 57 does not detect a candidate parking position because the aforementioned system conditions are not met (e.g., the shift position is not park or the user is wearing a seat belt), a display (guidance) different from the first help screen 40b or the second help screen 40c may be displayed on the display device of the HMI 13. For example, a visual message or other notification indicating that the system conditions (e.g., the shift position is park or the user is not wearing a seat belt) are not met may be displayed in the message display area 43 of the search screen 40d.

[0074] When the target parking position detection unit 57 detects a parking position candidate (that is, when the detection of the parking position candidate is successful), the HMI control unit 50 Figure 4 The detection success screen 40 a shown is displayed on the display device of the HMI 13 .

[0075] On the other hand, when the target parking position detector 57 cannot detect a parking position candidate (ie, when the parking position candidate detection fails), the HMI control unit 50 displays a detection failure screen on the display device of the HMI 13 to inform the user that the parking position candidate cannot be detected. Figure 10This is a schematic diagram of an example of a detection failure screen. For example, detection failure screen 40e includes a captured image 41, an overhead image 42, a message display area 43, a help button 49, and an end button 45. Message display area 43 may display a visual message or other notification informing the user that the parking assistance system 10 has detected a candidate parking location.

[0076] It should be noted that when the parking assistance device 10 is set to the automatic start mode, the HMI control unit 50 may automatically start displaying the detection success screen 40a if the parking position candidate is successfully detected. On the other hand, when the parking assistance device 10 is set to the automatic start mode, the detection failure screen 40e may not be automatically displayed even if the parking position candidate is unsuccessful. In this case, for example, the HMI control unit 50 may start displaying the detection failure screen 40e when the user operates the parking switch 17.

[0077] If the user presses the help button 49, the HMI control unit 50 detects the operation of the help button 49 via the touch panel provided on the display device. If the help button 49 is pressed, the HMI control unit 50 determines whether the failure to detect a candidate parking location is due to user factors or environmental factors. User factors in the first and second assist modes may include, for example, door mirrors being retracted, doors being open, or vehicle speed exceeding a threshold.

[0078] Figure 11 (a) and Figure 11 (b) is an explanatory diagram of another example of the user's reasons in the first assistance mode. Figure 11 (a) shows a scenario where a target parking position 31 has been pre-registered in the parking assistance device 10. Here, it is assumed that the host vehicle 1 is driven in the direction of arrow 37 and approaches the target parking position 31. The user manually drives the host vehicle 1 along the parking path 36 and parks it at the target parking position 31. The objects detected around the target parking position 31 are stored in the storage device 19b as learned objects.

[0079] Figure 11 (b) shows a scenario where the registered target parking position 31 is detected as a parking position candidate. Here, it is assumed that the host vehicle 1 is traveling in the direction of arrow 38 and approaches the target parking position 31 .

[0080] The user reason may also include: when detecting a candidate parking position, direction 38 of the vehicle 1 approaching the candidate parking position (i.e., target parking position 31) differing from direction 37 of the vehicle 1 approaching the target parking position 31 when parking the vehicle 1 at the target parking position 31 in order to store the target parking position 31 in the parking assist device 10. Specifically, the determination may be made based on the angle formed by direction 38 and direction 37 being greater than a predetermined value.

[0081] In addition, the user reasons in the first assistance mode may also include: when detecting a parking position candidate ( Figure 11 (b) When the current position 33 of the host vehicle 1 is away from the target parking position 31 to store the target parking position 31 in the parking assist device 10 ( Figure 11 (a)) The parking path 36. Specifically, it may be determined that the distance between the parking path 36 and the current position 33 of the host vehicle 1 is greater than or equal to a predetermined value.

[0082] If the reason why the parking position candidate cannot be detected is due to user error, the HMI control unit 50 will Figure 5 The first help screen 40b shown is displayed on the display device of the HMI 13. The HMI control unit 50 may also display visual messages such as "Approaching in the opposite direction from the registered direction," "Road surface position different from the registered position," "Mirrors closed," "Doors open," and "Speeding fast" in the user reason display area 46 of the first help screen 40b to inform the user of the above-mentioned user reasons (the direction 38 of the vehicle 1 approaching the candidate parking position when detecting the candidate parking position is different from the direction 37 of the vehicle 1 approaching the target parking position 31 when registering the target parking position 31, the current position 33 when detecting the candidate parking position is away from the parking path 36 when registering the target parking position 31, the door mirrors are retracted, the doors are open, and the vehicle speed is greater than a threshold value).

[0083] Environmental factors in the first and second assistance modes may include, for example, the inability to detect a candidate parking location due to an obstacle. Examples of environmental factors that may be considered inability to detect a candidate parking location due to an obstacle include: in the first assistance mode, an obstacle in the registered target parking location 31, or an obstacle on the path from the host vehicle 1 to the registered target parking location 31. Furthermore, for example, environmental factors may include: in the second assistance mode, an obstacle in a parking space around the host vehicle 1, or an obstacle on the path from the host vehicle 1 to the parking space.

[0084] An example of an environmental cause in the first assistance mode may be that the current position of the host vehicle 1 cannot be determined by the positioning device 11 during detection of a candidate parking position. An example of an environmental cause in the first assistance mode may be that a candidate parking position cannot be detected due to a difference between an image of an object present around the target parking position 31 detected when the learned target object data is stored in the storage device 19 b (i.e., when the target parking position 31 is registered) and an image of the surrounding objects detected during detection of the candidate parking position.

[0085] If the reason why the parking position candidate cannot be detected is due to environmental reasons, the HMI control unit 50 will Figure 6 The second help screen 40c is displayed on the display device of the HMI 13. The HMI control unit 50 may also display visual messages in the environmental cause display area 48 of the first help screen 40b to inform the user of the above-mentioned environmental causes (the parking position candidate cannot be detected due to an obstacle, the current position of the host vehicle 1 cannot be measured, and the parking position candidate cannot be detected due to a difference between the image of the target object detected when registering the target parking position 31 and the image of the target object detected when detecting the parking position candidate). The messages include "The target parking position cannot be detected if there is an obstacle in the parking space or if there is an obstacle between the vehicle and the parking space," "The target parking position cannot be detected if the GPS signal is continuously blocked," and "The target parking position may not be correctly detected if the image is significantly different from the image at the time of registration due to changes in ambient brightness, etc."

[0086] It should be noted that when both user reasons and environmental reasons exist, the HMI control unit 50 may prioritize displaying either the user reason or the environmental reason. For example, when the help button 49 is pressed, the HMI control unit 50 may prioritize displaying either the first help screen 40b or the second help screen 40c.

[0087] While user factors are factors that can be easily eliminated by the user, environmental factors are often difficult for the user to eliminate. Therefore, when both user factors and environmental factors exist, the HMI control unit 50 may display the environmental factors in priority over the user factors.

[0088] On the contrary, the HMI control unit 50 may prioritize the user factor over the environmental factor and display it. When the user factor and the environmental factor coexist, both the user factor and the environmental factor may be displayed.

[0089] It should be noted that, in the case of parking assist control in the second assist mode, the HMI control unit 50 may not display the first help screen 40b or the second help screen 40c. In this case, for example, the HMI control unit 50 may stop displaying the help button 49 on the detection failure screen 40e or disable the help button 49. The HMI control unit 50 may also display a user reason or an environmental reason in the message display area 43 of the detection failure screen 40e.

[0090] Figure 12 This is a flowchart of the driving assistance method according to the second embodiment. When parking assistance control is initiated, the HMI control unit 50 displays the search screen 40d in step S10. In step S11, the parking assistance control unit 51 determines whether the system conditions are met. If the system conditions are met (step S11: Y), the process proceeds to step S13. If the system conditions are not met (step S11: N), the process proceeds to step S12. In step S12, the HMI control unit 50 displays a message on the search screen 40d indicating that the system conditions are not met. The process then returns to step S11. In step S13, the target parking position detection unit 57 determines whether a parking position candidate can be detected. If a parking position candidate can be detected (step S13: Y), the process proceeds to step S14. If a parking position candidate cannot be detected (step S13: N), the process proceeds to step S18. In step S14, the HMI control unit 50 displays the detection success screen 40a.

[0091] In step S15 , the HMI control unit 50 determines whether the end button 45 has been operated. If the end button 45 has been operated (step S15 : Y), the process ends. If the end button 45 has not been operated (step S15 : N), the process proceeds to step S16 .

[0092] In step S16, the HMI control unit 50 determines whether the parking start button 44 has been operated. If the parking start button 44 has not been operated (step S16: N), the process returns to step S15. If the parking start button 44 has been operated (step S16: Y), the process proceeds to step S17. In step S17, the parking assist control unit 51 sets the detected parking position candidate as the target parking position 31. The target trajectory generation unit 59 calculates a target parking path from the current position 33 of the host vehicle 1 to the target parking position 31. The steering control unit 60 and the vehicle speed control unit 61 implement parking assist control for the host vehicle 1 based on the calculated target parking path 34. The process then terminates.

[0093] In step S18, the HMI control unit 50 displays the detection failure screen 40e. In step S19, the HMI control unit 50 determines whether the end button 45 has been pressed. If the end button 45 has been pressed (step S19: Y), the process ends. If the end button 45 has not been pressed (step S19: N), the process proceeds to step S20.

[0094] In step S20 , the HMI control unit 50 determines whether the HELP button 49 has been operated. If the HELP button 49 has not been operated (step S20 : ​​N), the process returns to step S19 . If the HELP button 49 has been operated (step S20 : ​​Y), the process proceeds to step S21 .

[0095] In step S21, the HMI control unit 50 determines whether the failure to detect a parking location candidate is due to user factors or environmental factors. If the failure to detect a parking location candidate is due to user factors (step S21: Y), the process proceeds to step S22. If the failure to detect a parking location candidate is due to environmental factors (step S21: N), the process proceeds to step S24.

[0096] In step S22, the HMI control unit 50 displays the first help screen 40b. In step S23, the HMI control unit 50 determines whether the return button 47 has been pressed. If the return button 47 has not been pressed (step S23: N), the process returns to step S22. If the return button 47 has been pressed (step S23: Y), the process returns to step S18.

[0097] In step S24, the HMI control unit 50 displays the second help screen 40c. In step S25, the HMI control unit 50 determines whether the return button 47 has been pressed. If the return button 47 has not been pressed (step S25: N), the process proceeds to step S24. If the return button 47 has been pressed (step S25: Y), the process returns to step S18.

[0098] In step S18 , the HMI control unit 50 displays the detection failure screen 40 e . In step S19 , if the end button 45 is operated (step S19 : Y), the process ends.

[0099] (Effects of Implementation Methods)

[0100] (1) The controller 19 assists the vehicle 1 in parking at the target parking position. If a parking position candidate that is a candidate for the target parking position and that exists around the vehicle 1 cannot be detected, the controller 19 displays the environmental reason on the display device if the reason for not being able to detect the parking position candidate is a factor dependent on the environment of the vehicle 1, i.e., an environmental reason. If the reason for not being able to detect the parking position candidate is a factor dependent on the user, i.e., a user reason, the controller 19 displays the user reason on the display device. This makes it easier for the user to cope with the situation where the target parking position cannot be detected.

[0101] (2) The controller 19 may determine whether a predetermined system condition for executing parking assist control is satisfied. If the system condition is satisfied, the controller 19 detects a candidate parking position. If the system condition is not satisfied, the controller 19 displays a display different from the display for environmental reasons and the display for user reasons on the display device. Thus, if the system condition is not satisfied, the target parking position detection process can be omitted, and the user can be notified that the system condition is not satisfied.

[0102] (3) In the driving assistance control of the first assistance mode, the controller 19 may pre-store data indicating the relative positional relationship between targets existing around the target parking position and the target parking position in a storage device as learned target object data, detect targets existing around the host vehicle 1, i.e., surrounding targets, and detect parking position candidates existing around the host vehicle 1 based on the learned target object data and the surrounding targets. Thus, the user can utilize the parking assistance control that assists the host vehicle 1 in parking at the pre-registered target parking position.

[0103] (4) In the driving assistance control of the first assistance mode, when the current position of the host vehicle 1 can be measured when detecting pre-stored parking position candidates, the controller 19 may detect objects that exist around the current position as surrounding objects. The environmental reason may include the inability to measure the current position of the host vehicle 1. Thus, the user can be notified that the target parking position cannot be detected because the current position of the host vehicle 1 cannot be measured.

[0104] (5) In the driving assistance control of the first assistance mode, the controller 19 may also indicate that the user reason includes: a first direction and a second direction are different, the first direction being the direction in which the vehicle 1 approaches the target parking position when detecting the pre-stored target parking position, and the second direction being the direction in which the vehicle 1 approaches the target parking position when parking the vehicle 1 at the target parking position in order to store the learned target object data in the storage device. Thus, the user can be notified that the target parking position cannot be detected because the directions in which the vehicle 1 approaches the target parking position differ when registering the target parking position and when detecting the registered target parking position.

[0105] (6) In the driving assistance control of the first assistance mode, the controller 19 may measure the current position of the host vehicle 1 when detecting a pre-stored parking position candidate. The user reason may also include: the measured current position is more than a predetermined distance away from a parking path, wherein the parking path is the path that the host vehicle 1 travels to the target parking position when the host vehicle 1 is parked at the target parking position in order to store the learned target object data in the storage device. In this way, the user can be notified that the target parking position cannot be detected due to departure from the parking path when the target parking position was registered.

[0106] (7) Environmental reasons may also include: the target parking position cannot be detected due to a difference between the image of the target object present in the vicinity of the target parking position when the learned target object data is stored in the storage device and the image of the detected surrounding target object. Thus, it is possible to notify the user that the target parking position cannot be detected due to a significant difference between the image of the target object detected when registering the target parking position and the image of the detected target object when the registered target parking position is detected.

[0107] (8) In the driving assistance control of the second assistance mode, the controller 19 may detect a parking-capable vacant space around the host vehicle 1 as a target parking position based on the detection result of white lines or objects around the host vehicle 1 by the sensor. This allows the user to utilize the parking assistance control that assists the host vehicle 1 in parking at a target parking position that is not pre-registered.

[0108] (9) Environmental reasons may also include: the target parking position cannot be detected due to an obstacle. In this way, the user can be informed that the target parking position cannot be detected due to an obstacle.

[0109] (10) When both an environmental reason and a user reason exist, the controller 19 may display one of the environmental reason and the user reason, but not the other. This allows the user to be informed of which reason is prioritized based on the nature of the reason for not being able to detect the target parking position.

[0110] For example, environmental factors may be displayed instead of user factors, thereby giving priority to notifying the user of environmental factors that are difficult to resolve.

[0111] Description of Reference Numerals

[0112] 1 vehicle

[0113] 10 Parking assistance device

[0114] 19 Controller

Claims

1. A parking assistance method for assisting a vehicle in parking at a target parking position, wherein: In a case where a parking position candidate existing around the host vehicle that is a candidate for the target parking position cannot be detected, when the reason for not being able to detect the parking position candidate is a reason dependent on the environment of the host vehicle, i.e., an environmental reason, the environmental reason is displayed on the display device; and when the reason for not being able to detect the parking position candidate is a reason dependent on the user, i.e., a user reason, the user reason is displayed on the display device.

2. The parking assistance method according to claim 1, characterized in that: determining whether a predetermined system condition for executing parking assist control for assisting the host vehicle in parking at the target parking position is satisfied, When the system condition is satisfied, the parking position candidate is detected, and when the system condition is not satisfied, a display different from the display due to the environmental factor and the display due to the user factor is displayed on the display device.

3. The parking assistance method according to claim 1 or 2, characterized in that: Data indicating the relative positional relationship between the target object existing around the target parking position and the target parking position is stored in advance in a storage device as learned target object data. detecting targets existing around the vehicle, i.e., surrounding targets; The parking position candidates existing around the host vehicle are detected based on the learned object data of the objects existing around the host vehicle and the surrounding objects.

4. The parking assistance method according to claim 3, characterized in that: When the current position of the host vehicle can be measured when detecting the pre-stored parking position candidate, objects existing around the current position are detected as the surrounding objects. The environmental reasons include: being unable to measure the current position of the host vehicle.

5. The parking assistance method according to claim 3, characterized in that: The user reasons include: a first direction and a second direction are different, the first direction is the direction in which the vehicle approaches the parking position candidate when detecting the pre-stored parking position candidate, and the second direction is the direction in which the vehicle approaches the target parking position when the vehicle is parked at the target parking position in order to store the learned target object data in the storage device.

6. The parking assistance method according to claim 3, characterized in that: When detecting the pre-stored parking position candidate, measuring the current position of the host vehicle, The user reason includes: the measured current position is more than a specified distance away from a parking path, and the parking path is the path that the vehicle travels to the target parking position when the vehicle is parked at the target parking position in order to store the learned target object data in the storage device.

7. The parking assistance method according to any one of claims 3 to 6, characterized in that: The environmental cause includes failure to detect the target parking position due to a difference between an image of an object existing around the target parking position and an image of the surrounding objects detected when storing the learned target object data in the storage device.

8. The parking assistance method according to claim 1 or 2, characterized in that: Based on a detection result of white lines or objects around the host vehicle by a sensor, a vacant space around the host vehicle where parking is possible is detected as the target parking position.

9. The parking assistance method according to any one of claims 1 to 7, characterized in that: The environmental reasons include: failure to detect the target parking position due to obstacles.

10. The parking assistance method according to any one of claims 1 to 9, characterized in that: When the environmental cause and the user cause exist at the same time, either one of the environmental cause and the user cause is displayed, and the other is not displayed.

11. The parking assistance method according to claim 10, characterized in that: The environmental reason is displayed, and the user reason is not displayed.

12. A parking assist device for assisting a vehicle in parking at a target parking position, characterized in that: have: storage device; display device; as well as The controller, when unable to detect a parking position candidate existing around the host vehicle that is a candidate for the target parking position, displays the environmental reason on the display device when the reason for not being able to detect the parking position candidate is a reason dependent on the environment of the host vehicle, i.e., an environmental reason; and displays the user reason on the display device when the reason for not being able to detect the parking position candidate is a reason dependent on the user, i.e., a user reason.

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