Parking assistance method and parking assistance device

Abstract

To provide a parking support method which calculates a target travel path through which a vehicle can move from a parking start position to a target parking position even when there is an obstacle between the parking start position and the target parking position.SOLUTION: A parking support method comprises the steps of: storing a travel path where a vehicle moves to a target parking position at the time of manually parking the vehicle, as an actual travel path (S2); detecting a distance between the vehicle moving on the actual travel path and an obstacle (S3); calculating a first target travel path being a travel path from a starting point of the actual travel path to the target parking position, based on relative positional relation between the starting position of the actual travel path and the target parking position (S5); calculating a difference obtained by subtracting the distance to the obstacle from a deviation between the actual travel path and the first target travel path (S6); calculating an approach range being a range including a position where the difference is a first prescribed distance or more among positions on the actual travel path, and setting a position within the approach range as a target intermediate position (S7); and calculating a second target travel path being a travel path from the parking start position through the target intermediate position to the target parking position (S12).SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] The following Patent Document 1 describes a parking assistance device that detects the position of an obstacle within a detection range around the vehicle at the parking start position, generates a movement path from the parking start position to a parking target position while avoiding the obstacle, and assists the vehicle in moving along the movement path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-60223 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if there is an obstacle between the parking start position and the target parking position, even if a target driving trajectory from the parking start position to the target parking position is generated based on the relative position of the parking start position with respect to the target parking position, the vehicle may not actually move along the target driving trajectory. An object of the present invention is to calculate a target driving trajectory that allows a vehicle to move from a parking start position to a target parking position even if there is an obstacle between the parking start position and the target parking position. [Means for solving the problem]

[0005] In one aspect of the parking assistance method of the present invention, the actual trajectory along which the vehicle moves to a target parking position when parking the vehicle by manual driving is stored as an actual driving trajectory, the distance between the vehicle and an obstacle while the vehicle is moving along the actual driving trajectory is detected, and a first target driving trajectory, which is a trajectory from the start point of the actual driving trajectory to the target parking position, is calculated based on the relative positional relationship between the start point of the actual driving trajectory and the target parking position, and a difference is calculated by subtracting the distance between an obstacle on either the right or left side, which is vertical to the extension direction of the actual driving trajectory, and the obstacle located in the direction in which the first target driving trajectory deviates from the actual driving trajectory, from the deviation of the first target driving trajectory, and an approach range is calculated, which is a range including points on the actual driving trajectory where the difference is equal to or greater than a first predetermined distance, and a point within the approach range is set as a target intermediate position, and when assisting parking of the vehicle at the target parking position, a second target driving trajectory, which is a trajectory from the parking start position, which is the position of the vehicle at the time parking is started, to the target parking position via the target intermediate position, and parking assistance control is executed to assist movement of the vehicle along the second target driving trajectory. [Effects of the Invention]

[0006] According to the present invention, even if there is an obstacle between the parking start position and the target parking position, it is possible to calculate a target driving trajectory that allows the vehicle to move from the parking start position to the target parking position. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a parking assistance device. [Figure 2A] FIG. 2 is an explanatory diagram of an example of a parking assistance method according to an embodiment. [Figure 2B] FIG. 10 is a schematic diagram showing an example of clearance from an obstacle and trajectory deviation. [Figure 3] 2 is a block diagram illustrating an example of a functional configuration of a controller in FIG. 1. FIG. [Figure 4A] FIG. 10 is an explanatory diagram of an example of setting a target intermediate position. [Figure 4B] FIG. 10 is a schematic diagram showing an example of clearance from an obstacle and trajectory deviation. [Figure 5A]FIG. 10 is an explanatory diagram of an example of setting a target intermediate position. [Figure 5B] FIG. 10 is a schematic diagram showing an example of clearance from an obstacle and trajectory deviation. [Figure 6A] FIG. 10 is an explanatory diagram of an example of calculation of a target traveling trajectory. [Figure 6B] FIG. 10 is an explanatory diagram of an example of calculation of a target traveling trajectory. [Figure 7] 10 is a flowchart of an example of a process executed when parking is performed by manual driving. [Figure 8] 10 is a flowchart illustrating an example of processing when parking assistance is performed. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the embodiments of the present invention shown below are examples of devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the structure, arrangement, etc. of component parts to those described below. The technical concept of the present invention can be modified in various ways within the technical scope defined by the claims.

[0009] (composition) Referring to FIG. 1, a vehicle 1 is equipped with a parking assistance device 10 that assists in parking the vehicle 1 at a target parking position. The parking assistance device 10 assists in driving the vehicle 1 along a target driving trajectory from its current position to the target parking position. Parking assistance by the parking assistance device 10 can take various forms. For example, automatic driving may be performed in which the vehicle 1 is controlled to drive to the target parking position along the target driving trajectory of the vehicle 1. Automatic driving in which the vehicle 1 is controlled to drive to the target parking position along the target driving trajectory of the vehicle 1 refers to control in which all or part of the steering angle, driving force, and braking force of the vehicle are controlled to automatically drive all or part of the vehicle 1 along the target driving trajectory. Parking of the vehicle 1 may also be assisted by displaying the target driving trajectory and the current position of the vehicle 1 on a display device visible to the occupants of the vehicle 1.

[0010] 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. The GNSS receiver may be, for example, a Global Positioning System (GPS) receiver or the like. The human-machine interface (HMI) 12 is an interface device that exchanges information between the parking assistance device 10 and the occupant. The HMI 12 includes a display device that can be seen by the occupant of the vehicle 1, a speaker, a buzzer, and controls (buttons, switches, levers, dials, touch panels, etc.).

[0011] The external sensor 14 detects objects within a predetermined distance range from the vehicle 1. The external sensor 14 detects the environment surrounding the vehicle 1, such as the relative position between the vehicle 1 and an object present around the vehicle 1, the distance between the vehicle 1 and the object, and the direction in which the object is present. The external sensor 14 may include, for example, a camera that captures the environment surrounding the vehicle 1. The camera may be, for example, an around-view monitor camera that captures the surroundings of the vehicle 1 and generates a captured image that is converted into an overhead image (around-view monitor image). The external sensor 14 may include a distance measuring device such as a sonar, a laser range finder, a radar, or a LiDAR (Light Detection and Ranging) laser radar.

[0012] Vehicle sensor 15 detects various information (vehicle information) of vehicle 1. Vehicle sensor 15 may include, for example, a vehicle speed sensor that detects the traveling speed of vehicle 1, a wheel speed sensor that detects the rotational speed of each tire equipped on vehicle 1, a three-axis acceleration sensor (G sensor) that detects acceleration (including deceleration) in three axial directions of vehicle 1, a steering angle sensor that detects the steering angle of the steering wheel, a turning angle sensor that detects the turning angle of the steered wheels, a gyro sensor that detects the angular velocity of vehicle 1, and a yaw rate sensor that detects the yaw rate.

[0013] The controller 16 is an electronic control unit that performs parking assistance control for the vehicle 1. The controller 16 includes a processor 20 and peripheral components such as a storage device 21. The processor 20 may be, for example, a CPU or an MPU. The storage device 21 may include a semiconductor storage device, a magnetic storage device, an optical storage device, or the like. The functions of the controller 16 described below are realized, for example, by the processor 20 executing a computer program stored in the storage device 21. Note that the controller 16 may also be formed by dedicated hardware for executing each of the information processes described below. The steering actuator 18a controls the steering direction and steering amount of the steering mechanism of the vehicle 1 in response to a control signal from the controller 16. The accelerator actuator 18b controls the accelerator opening of the drive device, which is the engine or drive motor, in response to a control signal from the controller 16. The brake actuator 18c activates the braking device in response to a control signal from the controller 16.

[0014] Next, parking assist control by the parking assist device 10 will be described. In parking assist control, the parking assist device 10 calculates the relative position of the parking start position with respect to the target parking position Pt. The parking start position is the position of the vehicle 1 at the time when parking assist control to the target parking position Pt is started. The parking assist device 10 calculates a target driving trajectory Tt for moving the vehicle 1 from the parking start position to the target parking position Pt based on the relative position of the parking start position with respect to the target parking position Pt. The parking assist device 10 executes parking assist control that assists the movement of the vehicle 1 along the target driving trajectory Tt. The target driving trajectory Tt is an example of a "second target driving trajectory" in the claims.

[0015] The relative position of the parking start position with respect to the target parking position Pt may be calculated, for example, by pre-storing the characteristic points and characteristic quantities of targets around the target parking position Pt and based on the stored characteristic points and characteristic quantities and the characteristic points and characteristic quantities of targets detected around the vehicle 1. For example, when parking the vehicle 1 at a target parking position Pt by manual driving, the parking assistance device 10 detects feature points and feature amounts of targets around the target parking position Pt, and stores the positions and feature amounts of the feature points relative to the target parking position Pt in the storage device 21. An operating mode in which the parking assistance device 10 stores the positions and feature amounts of the feature points of targets in the storage device 21 in this way is referred to as a "target learning mode." On the other hand, an operation mode that assists in parking the vehicle 1 at the target parking position Pt is referred to as a “parking assistance mode.” In the parking assistance mode, the parking assistance device 10 calculates the relative position of the parking start position with respect to the target parking position Pt based on the positions and feature amounts of the characteristic points of the target object with respect to the target parking position Pt around the stored target parking position Pt and the positions and feature amounts of the characteristic points of the target object with respect to the vehicle 1 detected around the vehicle 1, calculates a target traveling trajectory Tt based on the calculated relative position, and executes parking assistance control that assists in moving the vehicle 1 along the target traveling trajectory Tt.

[0016] Note that the description in this specification is not intended to limit the technical scope of the present invention to the method for calculating the relative position of the parking start position with respect to the target parking position Pt. The present invention is widely applicable to methods for calculating a target driving trajectory from the parking start position to the target parking position Pt. That is, the relative position of the parking start position with respect to the target parking position Pt can be obtained by various methods. For example, the target parking position Pt may be detected by detecting parking frame lines and parking spaces around the vehicle 1 with a camera of the external sensor 14, and the parking start position with respect to the target parking position Pt may be calculated.

[0017] As described above, in the parking assistance mode, a target driving trajectory Tt is calculated, which is a trajectory for moving the vehicle 1 from the parking start position to the target parking position Pt. However, there may be fixed obstacles such as pillars or trees between the parking start position and the target parking position Pt. In such cases, even if the target driving trajectory is generated based on the relative position of the parking start position with respect to the target parking position Pt, the vehicle may not be able to move along the target driving trajectory. Furthermore, if the target driving trajectory is corrected during movement from the parking start position to the target parking position Pt in order to avoid the above-mentioned obstacles, it may not be possible to generate a smooth target driving trajectory.

[0018] Therefore, the parking assistance device 10 of the embodiment stores the actual trajectory (hereinafter referred to as the "actual driving trajectory") that the vehicle 1 follows to move to the target parking position Pt when the vehicle 1 is manually parked. See Fig. 2A. The solid line Ta indicates the actual driving trajectory that the vehicle 1 follows when it is manually driven from the start point (start position) Ps to the target parking position Pt. Based on the actual traveling trajectory Ta, the parking assistance device 10 sets a target intermediate position (position Pi1 in the example of FIG. 2A) through which the vehicle 1 passes on the way from the parking start position to the target parking position Pt.

[0019] Specifically, the parking assistance device 10 detects distances CL and CR between the vehicle 1 moving along the actual travel path Ta and surrounding obstacles. In the following description, the distance between the vehicle 1 and surrounding obstacles is referred to as "clearance." In the examples in this specification, the clearances between the vehicle 1 and obstacles present on the left and right sides of the vehicle 1 when facing forward are referred to as clearances CL and CR, respectively. For example, Figure 2A shows that when the vehicle 1 is closest to an obstacle OL1 on the left side and an obstacle OR1 on the right side as viewed from the front of the vehicle body, the clearances CL and CR are CL1 and CR1, respectively. Note that in this embodiment, the left-right direction refers to the direction perpendicular to the direction in which the actual traveling path Ta extends (the tangential direction of the actual traveling path Ta). In other words, the right side and the left side refer to the right side and the left side of the vehicle on the actual traveling path Ta. Hereinafter, these will simply be referred to as the right side and the left side.

[0020] To set the target intermediate position, the parking assistance device 10 calculates a trajectory from the start point Ps of the actual traveling trajectory Ta to the target parking position Pt. The trajectory calculated to set the target intermediate position is referred to as a "generated trajectory." The generated trajectory is an example of the "first target traveling trajectory" or "third target traveling trajectory" in the claims. For example, FIG. 2A shows a generated trajectory Tc1 (broken line). The parking assistance device 10 calculates a "trajectory deviation" which is the deviation of the generated trajectory from the actual traveling trajectory Ta. The trajectory deviation may be defined as the distance between the actual traveling trajectory Ta and the generated trajectory in the normal direction of the actual traveling trajectory Ta, for example. For example, Fig. 2A shows the trajectory deviation dd1 of the generated trajectory Tc1 from the actual running trajectory Ta, and Fig. 2B shows the trajectory deviation dd1 and clearances CL and CR with respect to the position along the actual running trajectory Ta.

[0021] The parking assistance device 10 calculates a difference by subtracting the clearance between the vehicle 1 and an obstacle on the right or left side of the actual traveling trajectory Ta in a direction in which the generated trajectory deviates from the actual traveling trajectory Ta from the trajectory deviation. In the example of Figures 2A and 2B, a difference Δ1 is calculated by subtracting the clearance CL between the generated trajectory Tc1 and an obstacle OL1 in a direction in which the generated trajectory Tc1 deviates from the actual traveling trajectory Ta from the trajectory deviation dd1. The difference Δ1 is an index indicating how deeply the generated trajectory Tc1 intersects with the obstacle OL1. In the following description, the difference obtained by subtracting the clearance between the vehicle 1 and an obstacle that exists in the direction in which the generated trajectory deviates from the actual traveling trajectory Ta from the trajectory deviation is referred to as the "intersection degree." Point P1 is the point on the actual traveling trajectory Ta where the intersection degree Δ1 is greatest.

[0022] The parking assistance device 10 calculates an approach range that includes a portion of the actual traveling path Ta where the degree of intersection is equal to or greater than the first predetermined distance d1. For example, Fig. 2A shows an approach range R1 that includes a portion of the actual traveling path Ta where the degree of intersection is equal to or greater than the first predetermined distance d1. In the following description, a portion of the actual travel path Ta where the degree of intersection is equal to or greater than the first predetermined distance d1 will be referred to as an "approaching portion." For example, if the degree of intersection at a certain point on the actual travel path Ta is the first predetermined distance d1, and the degree of intersection before and after that point is less than the first predetermined distance d1, the approaching portion will be a single point on the actual travel path Ta. Also, for example, if the degree of intersection at two points on the actual travel path Ta is the first predetermined distance d1, and the degree of intersection in a section on the actual travel path Ta between these two points is continuously greater than the first predetermined distance d1, the section between these two points will be a single approaching portion.

[0023] The parking assistance device 10 may calculate a range that includes part or all of the approach portion as the approach range. For example, a single point on the actual traveling path Ta that is included in the approach portion may be calculated as the approach range. For example, in an approach portion having a non-zero length, a point on the actual traveling path Ta where the degree of intersection is greatest may be calculated as the approach range. For example, point P1 in FIG. 2A may be calculated as the approach range. Alternatively, for example, a plurality of points on the actual traveling trajectory Ta included in the approaching portion may be calculated as the approach range. For example, a plurality of points included in the approaching portion having a non-zero length may be calculated as the approach range. Also, for example, a part or all of the section of the approaching portion having a non-zero length may be calculated as the approach range.

[0024] Furthermore, when there are multiple approaching portions, a single point, multiple points, or section included in any of these approaching portions may be set as the approach range. For example, a single point, multiple points, or section included in an arbitrarily selected approaching portion from among these approaching portions may be set as the approach range. A single point, multiple points, or section included in the approaching portion with the greatest degree of intersection from among these approaching portions may be set as the approach range. Alternatively, for example, the approach range R1 may be a range within a second predetermined distance d2 from a single point, multiple points, or sections. The second predetermined distance d2 may be appropriately set to be shorter than the first predetermined distance d1. The parking assistance device 10 may also set the approach range to include approach portions of the actual driving trajectory Ta where the degree of intersection is equal to or greater than the first predetermined distance d1, and where the sum of the clearances (CL+CR) between the vehicle 1 and obstacles located on the right and left sides of the actual driving trajectory Ta is less than a predetermined threshold value.

[0025] The parking assistance device 10 sets a target intermediate position within the approach range. The target intermediate position may be set arbitrarily within the approach range. For example, FIG. 2A shows a target intermediate position Pi1 set within the approach range R1. The target intermediate position Pi1 may be set at a position equivalent to point P1. In other words, the target intermediate position may be set for each approach range at a point on the actual traveling trajectory Ta within the approach range that has the greatest degree of intersection. The target intermediate position Pi1 may be set at a position different from point P1. That is, the target intermediate position may be set for each approach range at a position different from the point on the actual traveling trajectory Ta within the approach range where the degree of intersection is greatest. In the example of FIG. 2A, the target intermediate position Pi1 may be set within a range of the second predetermined distance d2 from point P1.

[0026] The parking assistance device 10 calculates a trajectory from the parking start position to the target parking position Pt via the target intermediate position (target intermediate position Pi1 in the example of FIG. 2A) as the target driving trajectory Tt (dash-dotted line). In this way, by setting the target intermediate position based on the actual driving trajectory Ta that the vehicle 1 actually moves from the starting point Ps to the target parking position Pt by manual driving, and calculating the target driving trajectory Tt that leads from the parking start position to the target parking position Pt via the target intermediate position, it is possible to generate a target driving trajectory that the vehicle 1 can travel on even if there is an obstacle between the parking start position and the target parking position Pt. Furthermore, since a trajectory that passes through the target intermediate position Pi1 can be generated before starting movement from the parking start position to the target parking position Pt, a smooth target traveling trajectory can be generated.

[0027] The functional configuration of the controller 16 will be described in more detail below with reference to Fig. 3. The controller 16 functions as an image conversion unit 40, a self-position calculation unit 41, a feature point detection unit 42, a map data generation unit 43, an actual trajectory acquisition unit 44, a clearance detection unit 45, an intermediate position setting unit 46, a relative position calculation unit 47, a target trajectory generation unit 48, a steering control unit 49, a vehicle speed control unit 50, and an assistance image generation unit 51. The image conversion unit 40 converts the image captured by the camera of the external environment sensor 14 into an overhead image (around view monitor image) viewed from a virtual viewpoint directly above the vehicle 1. Hereinafter, the overhead image converted by the image conversion unit 40 may be referred to as a "surrounding image." The self-position calculation unit 41 calculates the current position of the vehicle 1 on a fixed coordinate system by dead reckoning or the like based on the vehicle information output from the vehicle sensor 15. A fixed coordinate system is a coordinate system (for example, a map coordinate system) with a specific point as the coordinate origin. The self-position calculation unit 41 may correct the calculated current position by map mapping or the like between target positions around the vehicle 1 detected by the external sensor 14 and known target positions or high-precision map information.

[0028] The feature point detection unit 42 detects feature points of targets around the vehicle 1 from the surrounding image output from the image conversion unit 40 and calculates feature amounts of the feature points. A feature point of the surrounding image is a point that has characteristics as a target, such as an edge point in the surrounding image, and a feature amount is information that represents the characteristics of the feature point, such as brightness on the image. The positions of the feature points detected from the surrounding image are expressed as coordinates in a coordinate system based on the current position of the vehicle 1 (hereinafter referred to as the "vehicle coordinate system"). Methods such as SIFT, SURF, ORB, BRIAK, KAZE, and AKAZE can be used to detect the feature points and calculate the image feature amounts. Note that the timing at which the feature point detection unit 42 detects feature points is not particularly limited, and for example, the feature point detection unit 42 may always detect feature points regardless of whether the operating mode of the parking assistance device 10 is the target learning mode or the parking assistance mode. Furthermore, the feature point detection unit 42 receives the current position of the vehicle 1 from the self-position calculation unit 41. The feature point detection unit 42 generates feature point data including the positions and feature amounts of the detected feature points, and the current position of the vehicle 1 at the time the feature points were detected. The feature point detection unit 42 outputs the feature point data to the map data generation unit 43 and the relative position calculation unit 47. Note that it is sufficient for the feature point detection unit 42 to be able to detect at least the positions of the feature points. In other words, it is sufficient for the feature point data to include at least the positions of the feature points and the current position of the vehicle 1, and detection of the feature amounts is not necessarily required.

[0029] When the operating mode of the parking assistance device 10 is the target object learning mode, the map data generation unit 43 stores the feature point data generated by the feature point detection unit 42 in the storage device 21. Hereinafter, the feature points stored in the storage device 21 may be referred to as "learned feature points." Furthermore, the map data generation unit 43 stores the position of the target parking position Pt in the storage device 21. For example, when the vehicle 1 is located at the target parking position Pt, the user of the vehicle 1 may input that the current position of the vehicle 1 is the target parking position Pt by operating the HMI 12. Also, in the target object learning mode, the current position of the vehicle 1 may be detected as the target parking position Pt when the user switches the shift position of the vehicle 1 to the parking range or applies the parking brake. In this way, by storing the positions of the learned feature points in the vehicle coordinate system, the position of the vehicle 1 in the fixed coordinate system at the time the learned feature points were detected, and the target parking position Pt in the fixed coordinate system, the relative positional relationship between the learned feature points and the target parking position Pt can be stored. Note that the manner in which the relative positional relationship between the learned feature points and the target parking position Pt is stored is not limited to the above-described manner, and for example, the positions of the learned feature points in a relative coordinate system based on the target parking position Pt may be stored.

[0030] The actual trajectory acquisition unit 44 acquires an actual traveling trajectory Ta, which is the actual trajectory along which the vehicle 1 moves to the target parking position Pt, while the vehicle 1 is being manually driven to be parked at the target parking position Pt. For example, the actual trajectory acquisition unit 44 may acquire the actual traveling trajectory Ta based on the sequence of points of the current position of the moving vehicle 1 by continuously receiving the current position of the vehicle 1 output from the self-position calculation unit 41 while the vehicle 1 is being manually driven to be parked at the target parking position Pt. The actual trajectory acquisition unit 44 may acquire the actual traveling trajectory Ta when the vehicle 1 is manually driven to park at the target parking position Pt in order to learn the feature points in the target learning mode. Alternatively, when parking the vehicle 1 at the target parking position Pt by manual driving, the actual traveling trajectory Ta may be acquired without learning the feature points. For example, the user of the vehicle 1 may operate the HMI 12 to instruct the start of acquisition of the actual traveling trajectory Ta. The actual trajectory acquisition unit 44 completes acquisition of the actual driving trajectory Ta when it detects that parking of the vehicle 1 through manual driving has been completed. The actual trajectory acquisition unit 44 stores the acquired actual driving trajectory Ta in the storage device 21. For example, the user of the vehicle 1 may instruct the completion of acquisition of the actual driving trajectory Ta by operating the HMI 12. The actual trajectory acquisition unit 44 may also detect the completion of parking of the vehicle 1 through manual driving when the user switches the shift position of the vehicle 1 to the parking range or applies the parking brake, or when the current position of the vehicle 1 reaches the target parking position Pt.

[0031] The clearance detection unit 45 detects clearances CL and CR between the vehicle 1 and obstacles around the vehicle 1 while the vehicle 1 is moving on the actual travel path Ta. For example, the clearance detection unit 45 detects the clearances CL and CR based on the distances to the objects around the vehicle 1 detected by the sonar of the external sensor 14. The clearance detection unit 45 stores the clearances CL and CR in the storage device 21. When parking of the vehicle 1 by manual driving is completed, the intermediate position setting unit 46 sets a target intermediate position based on the actual traveling trajectory Ta and the clearances CL and CR. 4A and 4B. When setting the first target intermediate position Pi1, the intermediate position setting unit 46 calculates a generated trajectory Tc1 that extends from the start point Ps of the actual traveling trajectory Ta to the target parking position Pt. For example, the intermediate position setting unit 46 may calculate a clothoid curve that connects the start point Ps and the target parking position Pt as the generated trajectory Tc1.

[0032] The intermediate position setting unit 46 calculates a trajectory deviation dd1, which is the deviation of the generated trajectory Tc1 from the actual traveling trajectory Ta. The intermediate position setting unit 46 calculates an intersection degree Δ1, which is the difference obtained by subtracting the clearance CL between the vehicle 1 and an obstacle OL1 that exists on the right or left side of the actual traveling trajectory Ta in a direction in which the generated trajectory Tc1 deviates from the actual traveling trajectory Ta, from the trajectory deviation dd1. The intermediate position setting unit 46 then determines whether an approaching portion exists where the intersection degree Δ1 is equal to or greater than a first predetermined distance d1. If an approaching portion does not exist, the intermediate position setting unit 46 does not set the first target intermediate position Pi1. In this case, no target intermediate position is set. If an approaching portion exists, the intermediate position setting unit 46 calculates an approaching range R1 that includes the approaching portion. If multiple approaching portions exist, the intermediate position setting unit 46 calculates an approaching range R1 that includes any one of these approaching portions. For example, the approaching range R1 may be set to include an approaching portion arbitrarily selected from these approaching portions or an approaching portion with the largest intersection degree.

[0033] The intermediate position setting unit 46 sets the target intermediate position Pi1 within the approach range R1. When setting the target intermediate position Pi1, the intermediate position setting unit 46 may calculate a trajectory from the start point Ps to the target parking position Pt via the target intermediate position Pi1, and determine whether the vehicle 1 can move on the calculated trajectory. If it is determined that the vehicle 1 cannot move on the calculated trajectory, the target intermediate position Pi1 may be reset to another point within the approach range R1. The intermediate position setting unit 46 may repeat the process of resetting the target intermediate position Pi1 within the approach range R1 until it can calculate a trajectory along which the vehicle 1 can move.

[0034] Once the target intermediate position Pi1 is set, the intermediate position setting unit 46 calculates a generated trajectory Tc2 that runs from the start point Ps via the target intermediate position Pi1 to the target parking position Pt. The generated trajectory Tc2 is an example of a "third target driving trajectory" in the claims. For example, the intermediate position setting unit 46 may calculate the generated trajectory Tc2 by connecting a clothoid curve that connects the start point Ps and the target intermediate position Pi1 with a clothoid curve that connects the target intermediate position Pi1 and the target parking position Pt. The intermediate position setting unit 46 calculates a trajectory deviation dd2, which is the deviation of the generated trajectory Tc2 from the actual traveling trajectory Ta.

[0035] 5A and 5B, the intermediate position setting unit 46 calculates an intersection degree Δ2, which is the difference obtained by subtracting the clearance CR between the vehicle 1 and an obstacle OR2 that exists on the right or left side of the actual traveling trajectory Ta in a direction in which the generated trajectory Tc2 deviates from the actual traveling trajectory Ta, from the trajectory deviation dd2. Then, it is determined whether there is an approaching portion where the intersection degree Δ2 is equal to or greater than the first predetermined distance d1, i.e., whether the intersection degree Δ2 is less than the first predetermined distance d1 from the start point Ps to the target parking position Pt. If there is no approaching portion, the intermediate position setting unit 46 does not set a second target intermediate position. In this case, only the target intermediate position Pi1 is set. If there is an approaching portion, the intermediate position setting unit 46 calculates an approaching range R2 that includes the approaching portion, and sets an additional target intermediate position Pi2 within the approaching range R2. Point P2 is the point on the actual traveling trajectory Ta where the degree of intersection Δ2 is greatest.

[0036] When multiple target intermediate positions Pi1, Pi2 are set, the intermediate position setting unit 46 sets the order of the target intermediate positions Pi1, Pi2 (hereinafter referred to as "intermediate position order") along the actual traveling trajectory Ta in order of furthest from the target parking position Pt (i.e., in order of closest to the start point Ps). In the following description, the order in which the target intermediate positions are set is referred to as "intermediate position order." The intermediate position setting unit 46 calculates a generated trajectory Tc3 that runs from the start point Ps through the target intermediate positions Pi1 and Pi2 to the target parking position Pt. The generated trajectory Tc3 is an example of a "third target driving trajectory" in the claims. In this case, the intermediate position setting unit 46 calculates the generated trajectory Tc3 so that it passes through the target intermediate positions Pi1 and Pi2 in the order of the intermediate positions. That is, the generated trajectory Tc3 starts from the start point Ps, passes through the target intermediate positions Pi1 and Pi2 in the order along the actual driving trajectory Ta in order of proximity to the start point Ps, and reaches the target parking position Pt. For example, in the example of FIG. 5B, the generated trajectory Tc3 is calculated to pass through the target intermediate positions Pi1 and Pi2 in that order. For example, the intermediate position setting unit 46 may calculate the generated trajectory Tc3 by connecting a clothoid curve connecting the starting point Ps and the target intermediate position Pi1, a clothoid curve connecting the target intermediate position Pi1 and the target intermediate position Pi2, and a clothoid curve connecting the target intermediate position Pi2 and the target parking position Pt.

[0037] The intermediate position setting unit 46 calculates a trajectory deviation dd3, which is the deviation of the generated trajectory Tc3 from the actual traveling trajectory Ta. The intermediate position setting unit 46 calculates the degree of intersection, which is the difference obtained by subtracting the clearance between the vehicle 1 and an obstacle that exists on the right or left side of the actual traveling trajectory Ta in the direction in which the generated trajectory Tc3 deviates from the actual traveling trajectory Ta, from the trajectory deviation dd3. Then, it is determined whether there is an approaching portion where the degree of intersection is equal to or greater than a first predetermined distance d1. If there is no approaching portion, the intermediate position setting unit 46 does not set a third target intermediate position. In this case, only the target intermediate positions Pi1 and Pi2 are set. If there is an approaching portion, the intermediate position setting unit 46 adds a third target intermediate position in the same manner as the method for setting the second target intermediate position Pi2. Subsequently, target intermediate positions are added until a generated trajectory is generated that does not have any approaching portions where the degree of intersection is equal to or greater than the first predetermined distance d1. When a generated trajectory is generated that does not have any approaching portions where the degree of intersection is equal to or greater than the first predetermined distance d1, the intermediate position setting unit 46 completes setting of the target intermediate position and stores the set target intermediate position in the storage device 21.

[0038] Note that an obstacle between the start point Ps and the target parking position Pt may be a temporary obstacle (e.g., a movable object). In this case, a target intermediate position may not be necessary. Therefore, the intermediate position setting unit 46 may receive a selection input from the user of the vehicle 1 to select one of the set target intermediate positions, and store only the selected target intermediate position in the storage device 21. For example, the intermediate position setting unit 46 displays a plurality of set target intermediate positions on the display device of the HMI 12, and accepts a selection input for selecting a target intermediate position to be stored from the displayed target intermediate positions using an operator of the HMI 12. The selection input may be, for example, an input specifying a target intermediate position to be registered, or an input specifying an unnecessary target intermediate position. Furthermore, for example, when N target intermediate positions are set, all combinations of 1 to N target intermediate positions are selected from these N target intermediate positions, and trajectories from the start point Ps to the target parking position Pt via the target intermediate positions included in the combinations are set, and an input specifying one of the displayed trajectories is accepted. In this case, the intermediate position setting unit 46 may store the target intermediate positions through which the specified trajectory passes in the storage device 21.

[0039] See FIG. 3. To start parking assist control that assists in parking the vehicle 1 at the target parking position Pt, the operation mode of the parking assist device 10 is switched to the parking assist mode. For example, the parking assist device 10 may switch the operation mode to the parking assist mode when the vehicle 1 is located near the target parking position Pt. At this time, the operation mode may be switched to the parking assist mode when the shift position is switched from the drive range to the reverse range, or from the reverse range to the drive range. The operation mode may also be switched to the parking assist mode when a "parking assist activation switch" provided in the HMI 12 is operated. The conditions for switching the operation mode to the parking assist mode can be set arbitrarily.

[0040] When the operation mode of the parking assistance device 10 is switched to the parking assistance mode, the relative position calculation unit 47 sets the current position of the vehicle 1 at the time when parking assistance control to the target parking position Pt is started as the parking start position Pps. The relative position calculation unit 47 also matches the learned feature points stored in the storage device 21 with the feature points of the feature point data output from the feature point detection unit 42, and associates identical feature points with each other. In the following description, the feature points detected around the vehicle 1 by the feature point detection unit 42 when the operation mode of the parking assistance device 10 is the parking assistance mode will be referred to as "surrounding feature points."

[0041] The relative position calculation unit 47 calculates the relative position of the parking start position Pps with respect to the target parking position Pt based on the relative positional relationship between the surrounding feature points and the vehicle 1 and the relative positional relationship between the learned feature points associated with the surrounding feature points and the target parking position Pt. For example, if the surrounding feature points are (x i ,y i ) and the surrounding feature points (x i ,y i ) are the trained feature points associated with each of (x mi ,y mi ) (i=1 to N). The relative position calculation unit 47 calculates the affine transformation matrix M affine Calculate.

number

[0042] Using the weighted least squares method, the column vector (a1, a2, a3, a4) is calculated as follows: T may be calculated.

number

number

[0043] The target trajectory generating unit 48 calculates the target driving trajectory Tt based on the relative position of the parking start position Pps with respect to the target parking position Pt and the target intermediate position. See FIG. 6A. The target trajectory generation unit 48 calculates the target driving trajectory Tt so that the target driving trajectory passes through the target intermediate positions Pi1 and Pi2 in the intermediate position order. That is, the target driving trajectory Tt is calculated to start from the parking start position Pps, pass through the target intermediate positions Pi1 and Pi2 in the intermediate position order (i.e., pass through the target intermediate positions Pi1 and Pi2 in the order along the actual driving trajectory Ta in order of furthest from the target parking position Pt), and reach the target parking position Pt. A well-known method adopted in automatic parking devices can be applied to calculate the target driving trajectory Tt. For example, the target driving trajectory Tt can be calculated by connecting the parking start position Pps to the target parking position Pt via the target intermediate positions Pi1 and Pi2 with a clothoid curve.

[0044] The target trajectory generating unit 48 may calculate a trajectory Tc from the parking start position Pps to the target parking position Pt before calculating the target driving trajectory Tt. For example, the target trajectory generating unit 48 may calculate the trajectory Tc by connecting the parking start position Pps to the target parking position Pt with a clothoid curve. The target trajectory generating unit 48 may calculate the target traveling trajectory Tt from the parking start position Pps to the target parking position Pt via the target intermediate positions Pi1 and Pi2 only when an obstacle exists on the trajectory Tc.

[0045] See Figure 6B. There are cases where the target driving trajectory Tt cannot be calculated so as to pass through all of the target intermediate positions Pi1 and Pi2 stored in the storage device 21. For example, if the parking start position Pps is closer to the target parking position Pt than a certain target intermediate position (target intermediate position Pi1 in the example of Figure 6B), the target driving trajectory Tt cannot be calculated so as to pass through this target intermediate position. This situation can occur, for example, when the driver manually drives the vehicle halfway through parking and starts parking assist control at a position closer to the target parking position Pt than the start point Ps of the actual driving trajectory Ta. In this case, the target trajectory generating unit 48 sequentially removes the target intermediate positions Pi1 and Pi2 read from the storage device 21 in the order of intermediate positions (i.e., in the order of furthest from the target parking position Pt along the actual traveling trajectory Ta), and calculates the target traveling trajectory Tt from the parking start position Pps to the target parking position Pt via the target intermediate positions that have not been removed. In the example of Fig. 6B, the target traveling trajectory Tt is calculated from the parking start position Pps to the target parking position Pt via the target intermediate position Pi2, excluding the target intermediate position Pi1.

[0046] Furthermore, the target trajectory generating unit 48 calculates a target vehicle speed profile for the vehicle 1 to travel along the target traveling trajectory Tt. For example, the target vehicle speed profile may be a vehicle speed profile in which the vehicle accelerates from the parking start position Pps to a predetermined set speed, then decelerates just before the target parking position Pt, and stops at the target parking position Pt. The set speed may be set based on the curvature of the calculated target traveling trajectory, such that the larger the curvature, the lower the speed. See Fig. 3. The target trajectory generating unit 48 outputs the target traveling trajectory Tt and the target vehicle speed profile to the steering control unit 49 and the vehicle speed control unit 50, respectively.

[0047] The steering control unit 49 controls the steering actuator 18a so that the vehicle 1 travels along the target travel trajectory Tt. The vehicle speed control unit 50 controls the accelerator actuator 18b and the brake actuator 18c so that the vehicle speed of the vehicle 1 changes in accordance with the target vehicle speed profile. In this way, the vehicle 1 is controlled to travel along the target travel trajectory Tt. The support image generation unit 51 generates a parking support image that represents the target travel trajectory Tt and the current position of the vehicle 1. For example, the parking support image may be an image in which the target travel trajectory Tt and the current position of the vehicle 1 are superimposed on a bird's-eye view image or an overhead view image of the surroundings of the vehicle 1. The support image generation unit 51 displays the parking support image on the display device of the HMI 12.

[0048] (operation) 7 is a flowchart of an example of processing executed when parking by manual driving is performed. In step S1, the feature point detection unit 42 stores feature points of targets around the vehicle 1 as learned feature points in the storage device 21. In step S2, the actual trajectory acquisition unit 44 acquires the actual traveling trajectory Ta and stores it in the storage device 21. In step S3, the clearance detection unit 45 detects clearances CL and CR between the vehicle 1 and obstacles around the vehicle 1 while the vehicle 1 is moving on the actual traveling trajectory Ta and stores them in the storage device 21.

[0049] In step S4, the parking assistance device 10 determines whether the vehicle 1 has reached the target parking position Pt. If the vehicle 1 has not reached the target parking position Pt (step S4: N), the process returns to step S1. If the vehicle 1 has reached the target parking position Pt (step S4: Y), the process proceeds to step S5. In step S5, the intermediate position setting unit 46 calculates the generated trajectory. In step S6, the intermediate position setting unit 46 calculates the trajectory deviation, which is the deviation of the generated trajectory from the actual driving trajectory Ta, and subtracts the clearance between the vehicle 1 and an obstacle that exists on the right or left side of the actual driving trajectory Ta in the direction in which the generated trajectory deviates from the actual driving trajectory Ta from the trajectory deviation dd1 to calculate the degree of intersection. The intermediate position setting unit 46 determines whether the degree of intersection from the start point Ps of the actual traveling trajectory Ta to the target parking position Pt is less than a first predetermined distance d1.

[0050] If the degree of intersection is not less than the first predetermined distance d1 (step S6: N), the process proceeds to step S7. If the degree of intersection is less than the first predetermined distance d1 (step S6: Y), the process proceeds to step S8. In step S7, the intermediate position setting unit 46 sets a target intermediate position within the approach range. If step S7 is executed two or more times in the processing loop S5 to S7, an additional target intermediate position is set from the second time onwards. Thereafter, the process returns to step S5. In step S8, the set target intermediate position is stored in the storage device 21. Thereafter, the process ends.

[0051] 8 is a flowchart of an example of processing when parking assistance is performed. In step S10, the relative position calculation unit 47 calculates the relative position of the target parking position Pt with respect to the parking start position Pps, which is the current position of the vehicle 1 at the time when parking assistance control is started. That is, it calculates the relative position of the parking start position Pps with respect to the target parking position Pt. In step S11, the target trajectory generation unit 48 reads the target intermediate position from the storage device 21. In step S12, the target trajectory generation unit 48 attempts to calculate a target driving trajectory Tt that leads from the parking start position Pps to the target parking position Pt via the read target intermediate position. In step S13, the target trajectory generating unit 48 determines whether or not the target running trajectory Tt has been calculated. If the target running trajectory Tt cannot be calculated (step S13: N), the process proceeds to step S14. If the target running trajectory Tt has been calculated (step S13: Y), the process proceeds to step S15.

[0052] In step S14, the target trajectory generating unit 48 removes the target intermediate position that is farthest from the target parking position Pt along the actual traveling trajectory Ta from among the target intermediate positions, after which the process returns to step S12. In step S15, the target trajectory generation unit 48 calculates a target vehicle speed profile for the vehicle 1 to travel along the target travel trajectory Tt. The steering control unit 49 controls the steering actuator 18a so that the vehicle 1 travels along the target travel trajectory Tt. The vehicle speed control unit 50 controls the accelerator actuator 18b and the brake actuator 18c so that the vehicle speed of the vehicle 1 changes according to the target vehicle speed profile. The processing ends when the vehicle 1 reaches the target parking position Pt.

[0053] (Effects of the embodiment) (1) The controller 16 stores the actual trajectory along which the vehicle 1 moves to the target parking position Pt when parking the vehicle 1 by manual driving as the actual driving trajectory Ta, detects the distance between the vehicle 1 moving along the actual driving trajectory Ta and an obstacle, calculates a first target driving trajectory, which is a trajectory from the start point Ps of the actual driving trajectory to the target parking position Pt, based on the relative positional relationship between the start point Ps of the actual driving trajectory Ta and the target parking position Pt, and calculates the distance between the first target driving trajectory and an obstacle located on either the right or left side, which is on both sides of the vertical direction relative to the extension direction of the actual driving trajectory Ta, in a direction in which the first target driving trajectory deviates from the actual driving trajectory Ta. The degree of intersection is calculated as the difference obtained by subtracting the deviation of the first target driving trajectory from the actual driving trajectory Ta from the deviation of the first target driving trajectory Ta; an approach range is calculated as a range including points on the actual driving trajectory Ta where the degree of intersection is equal to or greater than a first predetermined distance; a point within the approach range is set as a target intermediate position; and when assisting parking of the vehicle 1 at the target parking position Pt, a second target driving trajectory is calculated as a trajectory from the parking start position Pps, which is the position of the vehicle 1 at the time parking is started, to the target parking position Pt via the target intermediate position; and parking assist control is executed to assist movement of the vehicle 1 along the second target driving trajectory. In this way, by setting the target intermediate position based on the actual traveling trajectory Ta and calculating the target traveling trajectory from the parking start position to the target parking position Pt via the target intermediate position, it is possible to calculate a target traveling trajectory on which the vehicle can travel even if there is an obstacle between the parking start position and the target intermediate position. In addition, because a trajectory that passes through the target intermediate position can be generated before starting to move from the parking start position Pps to the target parking position Pt, a smooth target traveling trajectory can be generated.

[0054] (2) The controller 16 may set, for each approach range, a point on the actual traveling trajectory Ta within the approach range that is within a second predetermined distance range from the point with the greatest degree of intersection. The point with the greatest degree of intersection can be estimated as a point where the vehicle 1 has traveled so as to avoid the obstacle. By calculating a trajectory that passes through the target intermediate position set near such a point, it is possible to calculate a target traveling trajectory that avoids the obstacle. (3) The controller 16 may calculate as the approach range an area of ​​the actual driving trajectory Ta that includes a portion where the degree of intersection is equal to or greater than a first predetermined distance and where the sum of the distances between the vehicle 1 and obstacles located on the right and left sides of the actual driving trajectory Ta is equal to or less than a predetermined threshold. This makes it possible to calculate the area where the distance between the obstacles on the right and left sides of the actual traveling trajectory Ta is narrow as the approach range.

[0055] (4) When assisting the parking of the vehicle 1 into the target parking position Pt, the controller 16 may calculate a first trajectory from the parking start position Pps to the target parking position Pt, and only if an obstacle exists on the first trajectory, may calculate a second target driving trajectory from the parking start position Pps to the target parking position Pt via the target intermediate position. This prevents the controller 16 from unnecessarily calculating a second target driving trajectory that passes through the target intermediate position if there is no longer an obstacle when assisting the parking of the vehicle 1 into the target parking position Pt. (5) The controller 16 may (a1) calculate a second trajectory from the start point Ps to the target parking position Pt via the target intermediate position, (b1) determine whether the vehicle 1 can move on the second trajectory, and (c1) if it is determined that the vehicle 1 cannot move on the second trajectory, reset the target intermediate position to another point within the approach range. The controller 16 may repeat (a1) to (c1) until it is determined in (b1) that the vehicle 1 can move on the second trajectory. This allows the second target driving trajectory to be calculated so that the vehicle 1 can actually move.

[0056] (6) The controller 16 (a2) calculates a third target driving trajectory, which is a trajectory from the start point Ps to the target parking position Pt via the target intermediate position; (b2) calculates an intersection degree, which is the difference obtained by subtracting the distance between an obstacle on the right or left side of the actual driving trajectory Ta, which is located in the direction in which the third target driving trajectory deviates from the actual driving trajectory Ta, from the deviation of the third target driving trajectory from the actual driving trajectory Ta; (c2) determines whether the intersection degree is less than a first predetermined distance over the range from the start point Ps to the target parking position Pt; and (d2) if the intersection degree is not less than the first predetermined distance over the range from the start point Ps to the target parking position Pt, may set an additional target intermediate position within an approach range, which is a range including the portion of the actual driving trajectory Ta where the intersection degree is equal to or greater than the first predetermined distance. The controller 16 may repeat steps (a2) to (d2) until it is determined in step (c2) that the degree of intersection is less than the first predetermined distance over the range from the start point Ps to the target parking position Pt. This allows the controller 16 to calculate a second target driving trajectory that does not intersect with any obstacles.

[0057] (7) The controller 16 may receive a selection input from the user of the vehicle 1 to select one of the multiple set target intermediate positions, and calculate a second target traveling trajectory from the parking start position Pps to the target parking position Pt via the target intermediate position selected by the user. This makes it possible to avoid setting unnecessary target intermediate positions. (8) When the controller 16 cannot calculate the second target driving trajectory from the parking start position Pps to the target parking position Pt via multiple target intermediate positions, the controller 16 may remove target intermediate positions along the actual driving trajectory Ta in order of furthest from the target parking position Pt, and calculate the second target driving trajectory from the parking start position Pps to the target parking position Pt via the target intermediate positions that have not been removed from among the multiple target intermediate positions. This makes it possible to calculate the second target driving trajectory to the target parking position Pt even if parking assist control is started near a point midway along the actual driving trajectory Ta.

[0058] (9) The controller 16 may control the vehicle 1 so that the vehicle 1 moves along the second target traveling trajectory from the parking start position Pps to the target parking position Pt, and may display the second target traveling trajectory and the position of the vehicle 1 on a display device that is visible to the user of the vehicle 1. This can assist the user in parking the vehicle 1. (10) The controller 16 may calculate the second target driving trajectory by connecting the parking start position Pps and the target intermediate position, and the target intermediate position and the target parking position Pt, with clothoid curves, respectively. This allows the calculation of a smooth second target driving trajectory. [Explanation of symbols]

[0059] 1...vehicle, 10...parking assistance device, 11...positioning device, 12...human-machine interface, 14...external sensor, 15...vehicle sensor, 16...controller, 18a...steering actuator, 18b...accelerator actuator, 18c...brake actuator, 20...processor, 21...storage device, 40...image conversion unit, 41...self-position calculation unit, 42...feature point detection unit, 43...map data generation unit, 44...actual trajectory acquisition unit, 45...clearance detection unit, 46...intermediate position setting unit, 47...relative position calculation unit, 48...target trajectory generation unit, 49...steering control unit, 50...vehicle speed control unit, 51...assistance image generation unit

Claims

1. When parking a vehicle by manual driving, an actual trajectory along which the vehicle moves to a target parking position is stored as an actual driving trajectory; Detecting a distance between the vehicle moving along the actual travel path and an obstacle; Calculating a first target driving trajectory, which is a trajectory from the start point of the actual driving trajectory to the target parking position, based on a relative positional relationship between the start point of the actual driving trajectory and the target parking position; calculating a difference obtained by subtracting the distance between an obstacle present on either the right side or the left side of the actual traveling path in a direction in which the first target traveling path deviates from the actual traveling path from the deviation of the first target traveling path from the actual traveling path; calculating an approach range that includes points on the actual traveling path where the difference is equal to or greater than a first predetermined distance; a point within the approach range is set as a target intermediate position; When assisting parking of the vehicle at the target parking position, a second target driving trajectory is calculated, which is a trajectory from a parking start position, which is the position of the vehicle at the time of starting parking, to the target parking position via the target intermediate position; executing parking assist control to assist movement of the vehicle along the second target driving trajectory; A parking assistance method comprising:

2. 2. The parking assistance method according to claim 1, wherein, for each approach range, a point on the actual driving trajectory within the approach range that is within a second predetermined distance range from a point where the difference is longest is set as the target intermediate position.

3. 3. The parking assistance method according to claim 1, wherein the approach range is calculated to be an area of ​​the actual driving trajectory that includes a portion where the difference is equal to or greater than a first predetermined distance and where the sum of the distances between the vehicle and obstacles located on the right and left sides of the actual driving trajectory is equal to or less than a predetermined threshold.

4. At a time when assisting parking of the vehicle at the target parking position, a first trajectory from the parking start position to the target parking position is calculated; Only when an obstacle exists on the first trajectory, the second target traveling trajectory from the parking start position to the target parking position via the target intermediate position is calculated.

4. The parking assistance method according to claim 1, wherein the vehicle is driven in a direction parallel to the road surface.

5. (a1) calculating a second trajectory from the start point to the target parking position via the target intermediate position; (b1) determining whether the vehicle can move on the second track; (c1) when it is determined that the vehicle cannot move on the second track, resetting the target intermediate position to another point within the approach range; The parking assistance method according to any one of claims 1 to 4, wherein steps (a1) to (c1) are repeated until it is determined in step (b1) that the vehicle can move on the second track.

6. (a2) calculating a third target traveling trajectory that is a trajectory from the start point to the target parking position via the target intermediate position; (b2) calculating a second difference by subtracting the distance between the obstacle on the right side or left side of the actual traveling path and the third target traveling path, the distance being in a direction in which the third target traveling path deviates from the actual traveling path, from the deviation of the third target traveling path from the actual traveling path; (c2) determining whether the second difference is less than the first predetermined distance over a range from the start point to the target parking position; (d2) when the second difference is not less than the first predetermined distance over the range from the start point to the target parking position, set the additional target intermediate position within an approach range that is a range including a portion of the actual traveling trajectory where the second difference is equal to or greater than the first predetermined distance; The parking assistance method according to any one of claims 1 to 5, wherein steps (a2) to (d2) are repeated until it is determined in step (c2) that the second difference is less than the first predetermined distance over the range from the start point to the target parking position.

7. receiving a selection input from a user of the vehicle to select one of the plurality of set target intermediate positions; calculating the second target traveling trajectory from the parking start position to the target parking position via the target intermediate position selected by the user; 7. The parking assistance method according to claim 1, wherein the vehicle is driven in a direction parallel to the road surface.

8. 8. The parking assistance method according to claim 1, wherein, when it is not possible to calculate the second target driving trajectory from the parking start position to the target parking position via a plurality of the target intermediate positions, the target intermediate positions are removed along the actual driving trajectory in order of furthest from the target parking position, and the second target driving trajectory from the parking start position to the target parking position is calculated via the target intermediate positions that have not been removed from among the plurality of the target intermediate positions.

9. 9. The parking assistance method according to claim 1, wherein the vehicle is controlled so that the vehicle moves from the parking start position to the target parking position along the second target traveling trajectory.

10. 10. The parking assistance method according to claim 1, wherein the second target driving trajectory and the position of the vehicle are displayed on a display device that is visible to a user of the vehicle.

11. The parking assistance method according to any one of claims 1 to 10, characterized in that the second target driving trajectory is calculated by connecting the parking start position and the target intermediate position, and connecting the target intermediate position and the target parking position with a clothoid curve, respectively.

12. The actual trajectory along which the vehicle moves to a target parking position when parking the vehicle by manual driving is stored as an actual driving trajectory, the distance between the vehicle and an obstacle while the vehicle is moving along the actual driving trajectory is detected, and a first target driving trajectory, which is a trajectory from the start point of the actual driving trajectory to the target parking position, is calculated based on the relative positional relationship between the start point of the actual driving trajectory and the target parking position, and the distance between the obstacle and an obstacle present in a direction in which the first target driving trajectory deviates from the actual driving trajectory on either the right or left side that is on both sides in the vertical direction with respect to the extension direction of the actual driving trajectory is calculated as a distance from the actual driving trajectory to the first target driving trajectory. a controller that calculates a difference subtracted from a deviation of a driving trajectory, calculates an approach range that is a range that includes points on the actual driving trajectory where the difference is equal to or greater than a first predetermined distance, sets a point within the approach range as a target intermediate position, and, when assisting parking of the vehicle at the target parking position, calculates a second target driving trajectory that is a trajectory from a parking start position that is the position of the vehicle at the time parking is started to the target parking position via the target intermediate position, and executes parking assist control that assists movement of the vehicle along the second target driving trajectory.

Images