Parking assist system

Abstract

This system prevents the misidentification of objects that do not actually hinder vehicle movement as obstacles, without requiring any obstacle detection devices other than the object information acquisition device, and thus prevents the setting of an inefficient target trajectory. [Solution] When the vehicle is driving in the parking area, based on information acquired by the object information acquisition device, information on the driving area traveled by the vehicle and at least one of other vehicles is stored. Even if it is determined that there is an obstacle that would hinder the vehicle from moving along the target trajectory from the parking start position to the target parking position, if it is determined that the obstacle is within the driving area, the vehicle is automatically moved along the set target trajectory.

Description

[Technical Field]

[0001] The present invention relates to a parking assistance apparatus for vehicles such as automobiles, and more particularly to a parking assistance apparatus that moves a vehicle along a target trajectory by automatic driving. [Background Art]

[0002] As one type of parking assistance apparatus for vehicles such as automobiles, a parking assistance apparatus is known that sets a target trajectory from a parking start position to a target parking position based on target object information around the vehicle acquired by a target object information acquisition device, and moves the vehicle along the target trajectory by automatic driving.

[0003] It is also known in parking assistance control that if it is determined that there is an obstacle that impedes movement of the vehicle along the target trajectory from the parking start position to the target parking position, the parking assistance control is terminated, or the target trajectory is reset so that the obstacle does not become an impediment.

[0004] For example, Patent Document 1 below describes a parking assistance apparatus that generates a candidate route from the current position of the vehicle to the target parking position based on a travelable area of the vehicle recognized based on external environment information, provides a turn-back position at a predetermined position on the candidate route, generates a preliminary route from the turn-back position to the target parking position, and sets the candidate route as the target route when generation of the preliminary route is possible. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2019-182154 [Summary of the Invention]

[0006] [Problem to be Solved by the Invention] In conventional parking assist systems, a target trajectory is set based on information acquired by a target information acquisition device, and it is determined whether or not there are any obstacles that would hinder the vehicle's movement along the target trajectory. In this determination, targets that do not actually hinder the vehicle's movement, such as road markings, may be mistakenly identified as obstacles. As a result, parking assist control may be unnecessarily terminated and parking assistance may not be provided, or the target trajectory may be reset to an inefficient trajectory that avoids areas where the vehicle can actually move.

[0007] The present invention provides an improved parking assistance device that does not require any obstacle detection device other than the object information acquisition device, and prevents the occurrence of the aforementioned problems when an object that does not actually hinder the movement of the vehicle is mistakenly identified as an obstacle.

[0008] [Means for solving the problem and the effects of the invention] According to the present invention, a parking assistance device (100) is provided, which includes a target information acquisition device (18) that acquires information about targets around the vehicle (102), and a control unit (driving assistance ECU 10) that performs automatic parking control, which sets a target trajectory (110) from a parking start position (102A) to a target parking position (118) based on the information acquired by the target information acquisition device (S130), and controls the vehicle to automatically move along the target trajectory from the parking start position to the target parking position (S180~S220).

[0009] The control unit (driving support ECU 10) is configured to automatically move the vehicle along a pre-set target trajectory (S180~S220) when the vehicle is driving in the parking area (114) (S10, S30), based on the information acquired by the target information acquisition device, to store information on the driving area traveled by at least one of the vehicle and other vehicles (S40, S50). Even if it determines that there is an obstacle that would hinder the vehicle from moving along the target trajectory (110) from the parking start position to the target parking position (S140), if it determines that the obstacle is in the driving area (S150), it will automatically move the vehicle along the pre-set target trajectory.

[0010] According to the above configuration, when the vehicle is driving within the parking area, information about the driving area traveled by the vehicle and at least one other vehicle is stored based on information acquired by the target information acquisition device. Furthermore, even if an obstacle is determined to be in the way of the vehicle moving along the target trajectory from the parking start position to the target parking position, if the obstacle is determined to be within the driving area, the vehicle will automatically move along the pre-set target trajectory.

[0011] Therefore, it is possible to prevent the parking assistance control from unnecessarily terminating and parking assistance from being discontinued, and to prevent the target trajectory from being reset to an inefficient trajectory that avoids areas where the vehicle can actually move.

[0012] Furthermore, there is no need for any obstacle detection devices other than the target information acquisition device. Therefore, it is possible to avoid increasing the complexity of the parking assist system's structure and the high cost of the parking assist system.

[0013] [Aspects of the Invention] In one embodiment of the present invention, the control unit (driving support ECU 10) is configured to determine whether or not an obstacle is in the driving area based on information about the driving area stored from a point in time (Tp) prior to the time when the vehicle stops (S10 to S70, S150).

[0014] According to the above embodiment, whether or not an obstacle is in the driving area is determined based on information about the driving area stored from a predetermined time before the point in time when the vehicle stopped. Therefore, it is possible to prevent the determination of whether or not an obstacle is in the driving area based on old information about the driving area traveled by at least one of the vehicles, including the vehicle itself. In addition, the storage capacity required for the memory device that stores the driving area can be reduced.

[0015] In another embodiment of the present invention, the control unit (driving support ECU 10) is configured to determine that the vehicle is traveling in the parking area (S30) when it determines, based on information acquired by the target information acquisition device (18), that there is at least one parking space (116) within a predetermined distance (Le) from the vehicle (S10).

[0016] According to the above embodiment, when it is determined that there is at least one parking space within a preset distance range from the vehicle, based on the information acquired by the target information acquisition device, it is determined that the vehicle is driving in a parking area. Therefore, when the vehicle is driving in an area where parking is possible, it can be determined that the vehicle is driving in a parking area, and it is possible to prevent unnecessary acquisition and storage of driving area information when the vehicle is driving in an area where parking is not possible.

[0017] In another embodiment of the present invention, the control unit (driving support ECU 10) is configured to determine, based on information acquired by the target information acquisition device (18), that there is at least one parking space (116) within a preset distance range from the vehicle (S10) and that the vehicle speed (V) of the vehicle is less than or equal to a reference value (Vc) (S20), that the vehicle is traveling in the parking area (S30).

[0018] According to the above embodiment, based on the information acquired by the target information acquisition device, if it is determined that there is at least one parking space within a preset distance range from the vehicle and the vehicle's speed is below a standard value, it is determined that the vehicle is driving in the parking area. Therefore, even if the vehicle is driving in the parking area, if the vehicle is passing through the parking area without parking, it is possible to prevent the vehicle from being unnecessarily determined to be driving in the parking area, and to prevent the unnecessary acquisition and storage of information about the driving area.

[0019] In another aspect of the present invention, when the control unit (driving assistance ECU 10) determines that an obstacle is not within the travel region (S150), it is configured to reset the target trajectory (124) so that the host vehicle does not collide with the obstacle (S170).

[0020] According to the above aspect, when it is determined that an obstacle is not within the travel region, the target trajectory is reset so that the host vehicle does not collide with the obstacle. Therefore, this prevents parking assistance control from ending and parking assistance not being performed, and allows the host vehicle to be moved to the target parking position and parked while preventing the host vehicle from colliding with an obstacle.

[0021] Note that when the control unit cannot reset the target trajectory to prevent the host vehicle from colliding with an obstacle, it may be configured to notify the occupant that the target trajectory cannot be reset without automatically moving the host vehicle.

[0022] In the above description, to facilitate understanding of the present invention, names and / or reference numerals used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each constituent element of the present invention is not limited to the constituent elements of the embodiments corresponding to the names and / or reference numerals added in parentheses. Other objects, other features and attendant advantages of the present invention will be readily understood from the following description of embodiments of the present invention described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] [Figure 1] It is a schematic configuration diagram showing a parking control apparatus according to an embodiment. [Figure 2] It is a flowchart corresponding to a control program for acquiring travel region information in an embodiment. [Figure 3] It is a flowchart corresponding to an automatic parking control program in an embodiment. [Figure 4]This figure shows the case where a road marking is determined to be an obstacle and the road marking is within the travel area. [Figure 5] This figure shows the case where a road marking is determined to be an obstacle and the road marking is not within the travel area. [Figure 6] This figure shows the case where there is a stopped vehicle that obstructs the travel of the host vehicle and the stopped vehicle is determined to be an obstacle. Mode for Carrying Out the Invention

[0024] Hereinafter, a parking assistance apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0025] As shown in Fig. 1, a parking assistance apparatus 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving assistance ECU 10. The vehicle 102 is an autonomously drivable vehicle and includes a driving ECU 20, a braking ECU 30, an electric power steering ECU 40, and a meter ECU 50. ECU stands for Electronic Control Unit that primarily includes a microcomputer as its main component. Note that the vehicle 102 is referred to as the host vehicle 102 where necessary, and electric power steering is referred to as EPS.

[0026] The microcomputer of each ECU includes a CPU, a ROM, a RAM, a readable and writable non-volatile memory (N / M), and an interface (I / F), among other components. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are connected to each other such that data can be exchanged (communicable) via a CAN (Controller Area Network) 104. Accordingly, detection values from sensors (including switches) connected to a specific ECU are also transmitted to other ECUs.

[0027] The driver assistance ECU 10 is a central control unit that performs driver assistance control such as parking assistance control and inter-vehicle distance control. In this embodiment, the driver assistance ECU 10 works in cooperation with other ECUs to perform parking assistance control, as will be described in detail later.

[0028] The driver assistance ECU 10 is connected to a camera sensor 12, a radar sensor 14, and a switch 16. The camera sensor 12 and radar sensor 14 each include multiple camera devices and multiple radar devices, respectively. The camera sensor 12 and radar sensor 14 function as a target information acquisition device 18 that acquires target information around the vehicle 102.

[0029] Each camera device of the camera sensor 12, although not shown in the figure, includes a camera unit that photographs the area around the vehicle 102 and a recognition unit that analyzes the image data obtained from the camera unit to recognize road markings, other vehicles, and other objects. The recognition unit supplies information about the recognized objects to the driver assistance ECU 10 at predetermined intervals.

[0030] Each radar device of the radar sensor 14 uses millimeter-wave radio waves to detect the distance between the vehicle and the target, the relative speed between the vehicle and the target, and the relative position (direction) of the target relative to the vehicle, and supplies this information to the driver assistance ECU 10 at predetermined intervals. Alternatively, LiDAR (Light Detection and Ranging) may be used instead of, or in addition to, the radar sensor 14.

[0031] Switch 16 is located in a position accessible to the driver, similar to a steering wheel (not shown in Figure 1), and is operated by the driver. Switch 16 includes an automatic parking control switch and a parking start switch. As will be described in detail later, when the automatic parking control switch is ON, the driver assistance ECU 10 performs automatic parking control, and when the parking start switch is ON while automatic parking control is being performed, it starts controlling the movement of the vehicle by autonomous driving.

[0032] The drive ECU 20 is connected to a drive unit 22 that accelerates the vehicle 102 by applying driving force to the drive wheels 24. Normally, the drive ECU 20 controls the drive unit 22 so that the driving force generated by the drive unit 22 changes in accordance with the driver's driving operation, and when it receives a command signal from the driver assistance ECU 10, it controls the drive unit 22 based on the command signal. Therefore, the drive ECU 20 and the drive unit 22 work together to function as a drive control device 26.

[0033] The braking ECU 30 is connected to a braking device 32 that decelerates the vehicle 102 by applying braking force to the wheels 34. Normally, the braking ECU 30 controls the braking device 32 so that the braking force generated by the braking device 32 changes in accordance with the driver's braking operation. When it receives a command signal from the driver assistance ECU 10, it performs automatic braking by controlling the braking device 32 based on the command signal. Note that the wheels 34 include the drive wheels 24.

[0034] Therefore, the braking ECU 30 and the braking device 32 work together to function as a braking control device 36, which can control the braking force of the entire vehicle 102, as well as individually control the braking force of each wheel. When braking force is applied to the wheels due to parking control or other reasons, brake lights (not shown in Figure 1) are illuminated.

[0035] The EPS / ECU 40 is connected to the EPS device 42. Based on the steering torque and vehicle speed detected by the driving operation sensor 60 and vehicle condition sensor 70 (described later), the EPS / ECU 40 controls the steering assist torque in a manner known in the art, thereby reducing the driver's steering burden. Furthermore, by controlling the EPS device 42, the EPS / ECU 40 can steer the steering wheels 44 as needed. Therefore, the EPS / ECU 40 and the EPS device 42 function as a steering control device 46 that automatically steers the steering wheels as needed.

[0036] The drive control device 26, braking control device 36, and steering control device 46 work together with the driver assistance ECU 10 to function as an automated driving system 80 that moves the vehicle 102 by autonomous driving. As will be described in detail later, the driver assistance ECU 10 sets a target trajectory from the parking start position to the target parking position based on the information acquired by the target information acquisition device 18. Furthermore, the driver assistance ECU 10 controls the automated driving system 80 so that the vehicle moves by autonomous driving along the target trajectory from the parking start position to the target parking position.

[0037] The meter ECU 50 is connected to a touch-panel display 52 that displays the control status by the driver assistance ECU 10 and an alarm device 54 that issues alarms. The display 52 may be, for example, a multi-information display that displays meters and various other information, or it may be a display for a navigation system. When the display 52 receives a signal from the driver assistance ECU 10, it may display the status of the parking assistance control.

[0038] The warning device 54 is activated when it is determined that the vehicle 102 cannot be parked in the target parking position desired by the driver, and it notifies the driver that the vehicle cannot be parked. The warning device 54 may also be a device such as a warning lamp, a device that emits an audible warning such as a buzzer, etc.

[0039] The driving operation sensor 60 and the vehicle condition sensor 70 are also connected to CAN 104. Information detected by the driving operation sensor 60 and the vehicle condition sensor 70 (referred to as sensor information) is transmitted to CAN 104. The sensor information transmitted to CAN 104 can be used as appropriate by each ECU. Note that the sensor information may be information from a sensor connected to a specific ECU and transmitted to CAN 104 from that specific ECU.

[0040] The driving operation sensor 60 includes a drive operation amount sensor for detecting the amount of operation of the accelerator pedal, a braking operation amount sensor for detecting master cylinder pressure or the force applied to the brake pedal, and a brake switch for detecting whether or not the brake pedal is operated. The driving operation sensor 60 also includes a steering angle sensor for detecting the steering angle, a steering torque sensor for detecting the steering torque, and the like.

[0041] The vehicle condition sensor 70 includes a vehicle speed sensor for detecting the vehicle speed V of the vehicle 102, a longitudinal acceleration sensor for detecting the acceleration of the vehicle in the longitudinal direction, a lateral acceleration sensor for detecting the acceleration of the vehicle in the lateral direction, and a yaw rate sensor for detecting the yaw rate of the vehicle.

[0042] In this embodiment, the ROM of the driver assistance ECU 10 stores a program for acquiring information about the driving area corresponding to the flowchart shown in Figure 2 and a program for automatic parking control corresponding to the flowchart shown in Figure 3.

[0043] <Control program for acquiring information about the driving area (Figure 2)> Next, the control program for acquiring driving area information in the embodiment will be described with reference to the flowchart shown in Figure 2. The control for acquiring driving area information according to the flowchart shown in Figure 2 is performed by the CPU of the driver assistance ECU 10 when the ignition switch (IGSW), which is not shown in Figure 1, is ON.

[0044] First, in step S10, the CPU determines, based on the information acquired by the target information acquisition device 18, whether or not there is at least one parking space within a search range of a predetermined distance Lc (a positive constant) from the vehicle 102. If a negative determination is made, step S10 is repeated; if a positive determination is made, the control proceeds to step S20.

[0045] In step S20, the CPU determines whether the vehicle speed V is less than or equal to a reference value Vc (for example, a positive constant of 15 km / h). If a negative determination is made, it is assumed that the driver does not wish to park, so the control returns to step S10. If a positive determination is made, the control proceeds to step S30.

[0046] In step S30, the CPU determines that the vehicle 102 is driving within the parking area. Note that step S20 may be omitted, and the CPU may determine that the vehicle is driving within the parking area when a positive determination is made in step S10.

[0047] In step S40, the CPU acquires information on the travel area that the vehicle 102 traveled within the search range based on the information acquired by the target information acquisition device 18, and stores that information in RAM.

[0048] In step S50, the CPU acquires information on the travel area where other vehicles have traveled within the search range, based on the information acquired by the target information acquisition device 18, and stores this information in RAM. If there are multiple obstacles, travel area information is acquired and stored for each obstacle.

[0049] In step S60, the CPU determines whether the vehicle 102 has stopped or not. If the determination is negative, the control returns to step S10; if the determination is positive, the control proceeds to step S70.

[0050] In step S70, the CPU erases the driving area information stored in RAM that was stored before a predetermined Tp time (a positive constant) from the time the vehicle 102 stopped. In other words, information about driving areas far from the vehicle's current location is erased.

[0051] Furthermore, even after your own vehicle has stopped, information about the driving area traveled by other vehicles may be acquired and stored, for example, until the automatic parking control switch is turned on.

[0052] <Automatic parking control program (Figure 3)> Next, the automatic parking control program in the embodiment will be described with reference to the flowchart shown in Figure 3. The automatic parking control according to the flowchart shown in Figure 3 is executed by the CPU of the driver assistance ECU 10 when the automatic parking control switch is turned on.

[0053] First, in step S110, the CPU displays an overhead view of the vehicle 102 on the display unit 52. The display unit 52 may be configured so that a full-circumference overhead view, a left-side overhead view, a right-side overhead view, a front-side overhead view, and a rear-side overhead view can be selected and displayed by touching the image selection icon.

[0054] In step S120, the CPU determines whether the driver has determined a desired parking position (target parking position) by touching a parking space (parking area) displayed on the display unit 52. If the determination is negative, the control returns to step S110; if the determination is positive, the control proceeds to step S130. The driver may also be able to exit the vehicle 102 after determining a desired parking position and then provide necessary instructions regarding remote parking by operating a terminal device.

[0055] In step S130, the CPU sets a target trajectory from the current position of the vehicle 102 to the target parking position in a manner known in the art.

[0056] In step S140, the CPU determines, based on the information acquired by the target information acquisition device 18, whether or not there are any obstacles that would hinder the vehicle 102 from moving along the target trajectory from the parking start position to the target parking position. If a negative determination is made, the control proceeds to step S180; if a positive determination is made, the control proceeds to step S150.

[0057] In step S150, the CPU determines whether or not the obstacle is within the travel area stored in RAM. If the determination is positive, the control proceeds to step S180; if the determination is negative, the control proceeds to step S160. Note that if there are multiple obstacles, the positive determination is made only when all obstacles are within the travel area.

[0058] In step S160, the CPU determines whether it is possible to reset the target trajectory from the parking start position to the target parking position so that the vehicle does not collide with an obstacle. If a negative determination is made, that is, if it is determined that the target trajectory cannot be reset due to the obstacle, the control proceeds to step S230. On the other hand, if an affirmative determination is made, that is, if it is determined that the target trajectory can be reset so that the obstacle does not become an obstacle, the control proceeds to step S170.

[0059] In step S170, the CPU resets the target trajectory from the parking start position to the target parking position in a manner known in the art, so as to prevent the vehicle from colliding with an obstacle. If there are multiple obstacles, the CPU resets the target trajectory so as to prevent the vehicle from colliding with any of them.

[0060] In step S180, the CPU displays the target trajectory on the display unit 52 and also displays a "Start Parking" icon that functions similarly to the parking start switch. Multiple target trajectories may be displayed for selection.

[0061] In step S190, the CPU determines whether or not the vehicle 102 is permitted to move autonomously, either by operating the parking start switch or by touching the "Parking Start" icon displayed on the display unit 52. If a negative determination is made, the control returns to step S180; if a positive determination is made, the control proceeds to step S200. If multiple target trajectories are displayed, a positive determination is made when a target trajectory is selected by touch and then the vehicle is permitted to move autonomously.

[0062] In step S200, the CPU, in cooperation with other ECUs, automatically controls the drive unit 22, braking unit 32, and EPS unit 42 to move the vehicle 102 along the target trajectory to the target parking position through automated driving. The movement of the vehicle to the target parking position by automated driving is performed by the EPS unit 42 being automatically controlled so that the vehicle moves along the target trajectory, while the drive unit 22 and braking unit 32 may be controlled by the driver.

[0063] In step S210, the CPU determines whether the vehicle 102 has reached the target parking position based on the information acquired by the target information acquisition device 18. If the determination is negative, the control returns to step S200; if the determination is positive, the control proceeds to step S220.

[0064] In step S220, the CPU displays on the display unit 52 that the vehicle 102 has reached the target parking position and terminates this control. In the case of remote parking, the terminal device's display shows that the vehicle 102 has reached the target parking position. The shift position may be shifted to the P range and the ignition switch may be turned off.

[0065] In step S230, the CPU notifies the occupants that the target trajectory cannot be reset and that the automatic parking control is ending by displaying on the display unit 52 that the target trajectory cannot be reset, and then terminates the control. The warning device 54 may also be activated.

[0066] As can be seen from the above explanation, the parking assistance control in the embodiment is performed by controlling the acquisition of information about the driving area according to the flowchart shown in Figure 2, and by performing automatic parking control according to the flowchart shown in Figure 3.

[0067] In the control of acquiring information on the driving area (Figure 2), if it is determined that there is a parking space within the search range around the vehicle (S10), and the vehicle speed V is determined to be less than or equal to a reference value Vc (S20), it is determined that the vehicle is driving in the parking area (S30). Information on the driving area that the vehicle 102 has driven within the above search range is acquired and stored in RAM (S40). In addition, if another vehicle is driving within the above search range, information on the driving area that the other vehicle has driven is acquired and stored in RAM (S50).

[0068] Automatic parking control (Figure 3) is initiated when the automatic parking control switch is turned on. An overhead view of the area around the vehicle 102 is displayed on the display unit 52 (S110), and when the driver touches a parkingable location displayed on the display unit, the target parking location is determined (S120), and the target trajectory from the vehicle's current position to the target parking location is set (S130).

[0069] Once the target trajectory is set, the system determines, based on the information acquired by the target information acquisition device 18, whether or not there are any obstacles that would hinder the vehicle 102 from moving along the target trajectory from the parking start position to the target parking position (S140).

[0070] If an obstacle is detected, it is determined whether the obstacle is within the driving area stored in RAM (S150). If it is determined that the obstacle is not within the driving area, that is, if it is determined that the obstacle is an obstacle to the vehicle 102 moving along the target trajectory, it is determined whether the target trajectory can be readjusted so that the vehicle does not collide with the obstacle (S160).

[0071] If it is determined that the target trajectory cannot be reset, the crew is notified that the target trajectory cannot be reset (S230). Conversely, if it is determined that the target trajectory can be reset, the target trajectory is reset so that the vehicle does not collide with an obstacle (S170), and the target trajectory is displayed on the display unit 52 (S180).

[0072] Furthermore, if it is determined that there are no obstacles (S140), or if it is determined that there are obstacles but the obstacles are within the driving area (S150), the target trajectory is not reset and is displayed on the display unit 52 (S180).

[0073] Furthermore, when it is determined that the vehicle 102 is permitted to move by autonomous driving (S190), the vehicle moves to the target parking position by autonomous driving (S200). When it is determined that the vehicle has reached the target parking position (S210), this is displayed on the display unit 52, and the automatic parking control ends (S220).

[0074] <Operation of the Embodiment> (1) Cases where an object that is not an obstacle is determined to be an obstacle (Figures 4 and 5) Figures 4 and 5 illustrate a case where road markings 112A and 112B are located at or near the target trajectory 110 of the vehicle 102, and these road markings are determined to be obstacles even though they are not objects that would normally be considered an obstacle. The road markings are not limited to "slow down" and one-way arrows, but may also include other markings such as "stop."

[0075] In Figures 4, 5, and Figure 6 (described later), the vehicle 102 is shown at its current position, which is the parking start position 102A. 114 indicates the area of ​​the parking lot with multiple parking spaces 116, and 118 indicates the target parking position for the vehicle. Furthermore, 120 indicates the area traveled by the vehicle, and 122 indicates the area traveled by other vehicles.

[0076] In conventional parking assist systems, if road markings 112A and 112B are determined to be obstacles, it is determined that the target trajectory cannot be reset, and the automatic parking control terminates. Therefore, the vehicle is not moved to the target parking position by automatic driving.

[0077] (1-1) In the embodiment, when the object is in the travel area In Figure 4, since the road markings 112A and 112B are within the driving area 122, a positive determination is made in steps S140 and S150. That is, it is determined that the road markings 112A and 112B do not pose an obstacle to the movement of the vehicle along the target trajectory 110. Therefore, steps S180 to S220 are executed, and the automatic parking control does not terminate. As shown in Figure 4, the vehicle 102 moves to the target parking position 118 by automatic driving along the target trajectory 110 set in step S130. Point P indicates the turning point from forward to reverse.

[0078] (1-2) In the embodiment, when the object is not in the travel area In Figure 5, road marking 112B is within the driving area 122, but road marking 112A is not. In step S140, an affirmative determination is made, but in step S150, a negative determination is made. Therefore, if the target trajectory can be reset, an affirmative determination is made in step S160, and the target trajectory is reset in step S170. Furthermore, steps S180 to S220 are executed, so the automatic parking control does not end. As shown in Figure 5, the vehicle 102 moves to the target parking position 118 by automatic driving along the target trajectory 124 that was reset in step S170.

[0079] Therefore, in both cases (1-1) and (1-2) above, the vehicle 102 can be moved to the target parking position 118 by autonomous driving along the target trajectory.

[0080] In the cases of (1-2) and (1-2), if it is not possible to reset the target trajectory, a negative determination is made in step S160, and in step S230, the occupants are informed that it is not possible to reset the target trajectory and that the automatic parking control will be terminated, and the automatic parking control is terminated.

[0081] (2) When the object causing the obstruction is determined to be an obstacle (Figure 6) Figure 6 shows a case where an object 126 that obstructs the movement of the vehicle 102 is located at or near the target trajectory 110 of the vehicle 102, and that object is determined to be an obstacle. Note that the obstructing object is a stationary vehicle, but it may be any object that obstructs the vehicle moving along the target trajectory.

[0082] In this case, an affirmative determination is made in step S140, but a negative determination is made in step S150. Therefore, the same automatic parking control as in case (1-2) above is performed.

[0083] (3) When it is determined that there are no obstacles Although not shown in the diagram, if there are no objects that would obstruct the movement of the vehicle 102 at or near the target trajectory of the vehicle, a negative determination is made in step S140. Therefore, steps S180 to S220 are executed, and as in case (1) above, the vehicle moves to the target parking position 118 by automatic driving along the target trajectory set in step S130.

[0084] As can be seen from the above description, according to the embodiment, when the vehicle 102 is traveling in the parking area 114 (S10), information on the travel area 122 traveled by at least one of the vehicle and other vehicles is stored based on the information acquired by the target information acquisition device 18 (S40, S50). Furthermore, even if it is determined that there is an obstacle that would hinder the vehicle from moving along the target trajectory 110 from the parking start position 102A to the target parking position 118 (S140), if it is determined that the obstacle is in the travel area (S150), the vehicle will automatically move along the set target trajectory (S180~S220).

[0085] Therefore, it is possible to prevent the parking assistance control from unnecessarily terminating and parking assistance from being discontinued, and to prevent the target trajectory from being reset to an inefficient trajectory that avoids areas where the vehicle can actually move.

[0086] Furthermore, no other obstacle detection devices are required besides the target information acquisition device 18. Therefore, it is possible to avoid increasing the complexity of the parking assistance system's structure and the high cost of the parking assistance system.

[0087] Furthermore, according to the embodiment, it is determined whether or not an obstacle is in the driving area based on the driving area information stored from a point in time Tp prior to the time when the vehicle stopped (S10-S70, S150).

[0088] Therefore, it is possible to prevent the determination of whether or not an obstacle is in the driving area based on outdated information regarding the driving area traveled by at least one of the vehicles, including the own vehicle and other vehicles. In addition, the storage capacity required for the memory device that stores the driving area can be reduced.

[0089] Furthermore, according to the embodiment, based on the information acquired by the target information acquisition device 18, it is determined that there is at least one parking space 116 within a preset distance Le from the vehicle 102 (S10) and the vehicle speed V of the vehicle is less than or equal to a reference value Vc (S20), in which case it is determined that the vehicle is driving in the parking area (S30).

[0090] Therefore, when your vehicle is driving in an area where parking is possible, it can be determined that your vehicle is driving in a parking area, and when your vehicle is driving in an area where parking is not possible, it is possible to prevent unnecessary storage of information about the driving area. Also, even if your vehicle is driving in a parking area, if your vehicle is passing through the parking area without parking, it will be unnecessarily determined that your vehicle is driving in a parking area, and it is possible to prevent unnecessary acquisition and storage of information about the driving area.

[0091] Furthermore, according to this embodiment, when it is determined that there is no obstacle within the driving area (S150), the target trajectory 124 is reset so that the vehicle 102 does not collide with the obstacle (S170). This prevents the parking assistance control from ending and parking assistance from ceasing, and allows the vehicle to move to the target parking position and park without colliding with an obstacle.

[0092] Although the present invention has been described in detail above with respect to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described above, and that various other embodiments are possible within the scope of the present invention.

[0093] For example, in the embodiment described above, step S10 determines whether or not there is at least one parking space within the search range around the vehicle 102. However, instead of or in addition to step S10, a determination may be made based on information from the navigation device as to whether or not the vehicle is traveling in the parking area.

[0094] Furthermore, in the above-described embodiment, if it is determined in step S150 that the obstacle is not within the driving area stored in RAM, the control proceeds to step S160. However, if it is determined that the obstacle is not within the driving area stored in RAM, the automatic parking control may be terminated without steps S160 and S170 being executed.

[0095] Furthermore, in the above-described embodiment, in step S110, an overhead image of the area around the vehicle 102 is displayed on the display unit 52, and in step S120, if it is determined that the target parking position has been determined, in step S130, a target trajectory from the current position of the vehicle 102 to the target parking position is set. However, the target trajectory may be set in any manner known in the art. [Explanation of Symbols]

[0096] 10…Driver assistance ECU, 16…Switch, 18…Target information acquisition device, 80…Automated driving system, 100…Parking assistance system, 102…Vehicle, 102A…Parking start position, 110…Target trajectory, 112A,112B…Road markings, 114…Parking area, 116…Parking space, 118…Target parking position, 120,122…Driving area

Claims

1. A parking assistance device comprising: a target information acquisition device that acquires information about targets around the vehicle; and a control unit that sets a target trajectory from a parking start position to a target parking position based on the information acquired by the target information acquisition device, and performs automatic parking control to control the vehicle to automatically move along the target trajectory from the parking start position to the target parking position, The control unit is configured to store information about the driving area traveled by at least one of the vehicles, including the vehicle itself and other vehicles, based on information acquired by the target information acquisition device when the vehicle is driving in the parking area, and to automatically move the vehicle along the set target trajectory if it determines that there is an obstacle that would hinder the vehicle from moving along the target trajectory from the parking start position to the target parking position, and if it determines that the obstacle is in the driving area, the control unit is configured to automatically move the vehicle along the set target trajectory.

2. A parking assistance device according to claim 1, wherein the control unit is configured to determine whether or not an obstacle is in the driving area based on information of the driving area stored from a time prior to a predetermined time before the time the vehicle comes to a stop.

3. A parking assistance device according to claim 1, wherein the control unit is configured to determine that the vehicle is driving in the parking area when it determines, based on information acquired by the target information acquisition device, that there is at least one parking space within a predetermined distance range from the vehicle.

4. A parking assistance device according to claim 3, wherein the control unit is configured to determine that the vehicle is traveling in the parking area when, based on information acquired by the target information acquisition device, there is at least one parking space within a predetermined distance range from the vehicle and the vehicle speed of the vehicle is below a reference value.

5. A parking assistance device according to claim 1, wherein the control unit is configured to readjust the target trajectory so that the vehicle does not collide with an obstacle when it determines that there is no obstacle within the driving area.

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