Parking assistance method and parking assistance device

Abstract

To eliminate necessity for a large-capacity memory by suppressing a memory capacity from increasing to prevent cost increase of a device.SOLUTION: In a parking support method, positions of targets put around a target parking position are detected when an own vehicle is parked at the target parking position, and when the detected positions of the targets are different from positions of the targets memorized in a memorizing part 7, the detected positions of the targets are memorized, as temporarily-registered positions of the targets, in the memorizing part 7, and only the position of the target satisfying a predetermined condition of the temporarily registered positions of the target is memorized, as a finally-registered position of the target, in the memorizing part 7. The predetermined condition is as follows: the temporarily-registered positions of the targets match with the detected position of the target by more than predetermined number of times, in parking the vehicle at the target parking position by predetermined number of times of parking executed after the positions are temporarily registered.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Conventionally, a patent document 1 discloses an automatic driving control device that automatically parks a vehicle in a parking space. In the automatic driving control device disclosed in patent document 1, feature points determined to be structures arranged around the parking space are selected, and information on the selected feature points is stored in a memory.

Prior Art Documents

Patent Documents

[0003] / / 这里原内容可能有误,推测是想表达 ,翻译时按此处理

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described conventional automatic driving control device, since new feature points are stored in the memory every time the vehicle parks in a parking space, the required memory capacity increases. As a result, a large-capacity memory is required, and there is a problem that the cost of the device increases.

[0005] / / 这里原内容可能有误,推测是想表达 ,翻译时按此处理 Therefore, the present invention has been proposed in view of the above circumstances, and an object thereof is to provide a parking assistance method and an apparatus thereof that can eliminate the need for a large-capacity memory by suppressing an increase in the memory capacity and prevent an increase in the cost of the apparatus.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, a parking assistance method and apparatus according to one aspect of the present invention detects the position of an object in the vicinity of a target parking position when the vehicle is parked at the target parking position. If the detected object's position differs from the object's position stored in the memory unit, the detected object's position is stored in the memory unit as a temporarily registered object's position. Furthermore, only the object's positions that satisfy a predetermined condition are stored in the memory unit as permanently registered object's positions. Here, the predetermined condition is that the temporarily registered object's position matches the detected object's position a predetermined number of times or more during a predetermined number of parking attempts to the target parking position performed after the temporary registration. [Effects of the Invention]

[0007] According to the present invention, since the increase in memory capacity can be suppressed, it becomes unnecessary to require large-capacity memory, and thus the cost of the device can be prevented from increasing. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a block diagram showing the configuration of a vehicle system equipped with a parking assist device according to one embodiment. [Figure 2] Figure 2 is a diagram illustrating a method for registering the position of an object using a parking assistance device according to one embodiment. [Figure 3] Figure 3 is a flowchart showing the processing procedure for parking assistance by a parking assistance device according to one embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment to which the present invention is applied will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals, and detailed descriptions are omitted.

[0010] [Vehicle System Configuration] Figure 1 is a block diagram showing the configuration of a vehicle system equipped with a parking assist device according to this embodiment. As shown in Figure 1, the vehicle system 100 includes a parking assist device 1, a sensor 3, a GNSS receiver 5, and a storage unit 7. The vehicle system 100 is installed in vehicles capable of autonomous driving or vehicles that provide driving assistance to the driver.

[0011] The parking assistance device 1 stores the positions of landmarks around the target parking position where the vehicle has parked in the past in the storage unit 7. It then compares the positions of the landmarks stored in the storage unit 7 with the positions of landmarks detected when the vehicle parks at the target parking position to assist in parking the vehicle. At this time, the parking assistance device 1 detects the positions of landmarks around the target parking position. If the detected position of a landmark differs from the position of a landmark stored in the storage unit 7, it stores the detected position of the landmark in the storage unit 7 as a temporarily registered landmark position. Then, from among the temporarily registered landmark positions, only the positions of landmarks that meet predetermined conditions are stored in the storage unit 7 as permanently registered landmark positions. This allows only the positions of landmarks effective for parking assistance to be stored in the storage unit 7, thereby suppressing an increase in memory capacity and preventing an increase in costs.

[0012] Sensor 3 includes, for example, a camera, a radar sensor, etc. The camera may be, for example, a CCD (Charge Coupled Devices) camera or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. It may also be a monocular camera such as a near-infrared camera, or a stereo camera. The camera continuously captures images of the area around the vehicle at a predetermined frame rate, and the sequentially captured images are output sequentially as sensing information to the parking assist device 1 and recorded in the storage unit 7.

[0013] The radar sensor includes radar and LiDAR (Light Detection and Ranging). The radar and LiDAR are sensors mounted on the vehicle that detect objects in the vehicle's surroundings and measure the distance to each point on the detected object. The distance measured by the radar sensor is output to the parking assist device 1 and recorded in the storage unit 7.

[0014] The GNSS receiver 5 receives GNSS signals from GNSS (Global Navigation Satellite System) satellites and outputs them to the parking assist device 1. The GNSS signals are recorded in the storage unit 7.

[0015] The memory unit 7 is a recording means that stores information necessary for executing the parking assistance process by the parking assistance device 1, and is a database or memory. In particular, the memory unit 7 stores the positions of objects detected when the vehicle parks at a target parking position. The stored object positions include temporarily registered object positions and permanently registered object positions, which are distinguished and stored using tags or the like. The memory unit 7 also stores target parking positions and map information where the vehicle has parked in the past. The map information is, for example, a high-precision map, which may be obtained from an external server, or it may be created by the vehicle based on sensing results from sensors such as radar and LiDAR 3.

[0016] As shown in Figure 1, the parking assistance device 1 comprises a parking position setting unit 11, a target detection unit 13, a target registration unit 15, and a parking assistance unit 17.

[0017] The parking position setting unit 11 detects the vehicle's current position based on the GNSS signal received by the GNSS receiver unit 5, and if there is a parking space where the vehicle has been parked in the past around the vehicle, it sets that parking space as the target parking position. The target parking position may be automatically set to the parking space closest to the vehicle, or if there are multiple parking spaces, the driver may manually select and set it.

[0018] The target detection unit 13 detects targets existing around the host vehicle based on the sensor data acquired by the sensor 3. In particular, when the host vehicle parks at the target parking position, the target detection unit 13 detects the positions of the targets around the target parking position.

[0019] The target registration unit 15 compares the positions of the targets detected by the target detection unit 13 with the positions of the targets stored in the storage unit 7. If they are different, the target registration unit 15 stores the detected target positions in the storage unit 7 as the positions of the temporarily registered targets. That is, when a new target not stored in the storage unit 7 is detected, the target registration unit 15 temporarily stores the position of that target in the storage unit 7.

[0020] After that, the target registration unit 15 stores only the positions of the targets that meet the predetermined conditions among the positions of the temporarily registered targets in the storage unit 7 as the positions of the officially registered targets. This predetermined condition is that the position of the temporarily registered target matches the detected target position a predetermined number of times or more during the parking at the target parking position for the predetermined number of parking times executed after the temporary registration. For example, assume there is a position x1 of a target detected and temporarily registered around the target parking position X, and the host vehicle parks at the target parking position X three times after the temporary registration. If the position x1 of the temporarily registered target matches the detected target position two or more times during these three parkings, it is stored in the storage unit 7 as the position of the officially registered target.

[0021] Here, referring to FIG. 2, the method of registering the target positions will be described. As shown in FIG. 2, when the host vehicle A parks at the target parking position X for the first time and the target positions x11 - x14 are detected, since these target positions x11 - x14 are not yet stored in the storage unit 7, all of them are temporarily registered.

[0022] After that, when the host vehicle A parks at the target parking position X for the second time, the positions x11 - x14 of the targets that have already been temporarily registered are indicated by shaded stars, and the positions x21, x22, x24, x25 of the targets detected during the second parking are indicated by white stars. Since the position x11 of the target is determined to match when compared with the position x21 of the target detected during the second parking, the number of matches for the position x11 of the target is counted as "1". Similarly, the number of matches for the positions x12 and x14 of the targets is also counted as "1".

[0023] On the other hand, since no matching target is detected for the position x13 of the target during the second parking, the number of matches for the position x13 of the target remains "0". Furthermore, since no newly detected matching target exists for the position x25 of the target during the second parking, it is temporarily registered.

[0024] Next, when the host vehicle A parks at the target parking position X for the third time, the position x11 of the target is determined to match when compared with the position x31 of the target detected during the third parking, so the number of matches for the position x11 of the target is counted as "2". Similarly, the number of matches for the positions x12 and x14 of the targets is also counted as "2". As a result, the positions x11, x12, and x14 of the targets are stored in the storage unit 7 as the positions of the officially registered targets because they match the positions of the detected targets two or more times during the three parkings.

[0025] On the other hand, since no matching target is detected for the position x13 of the target even during the third parking, the number of matches remains "0". As a result, the position x13 of the target is deleted from the storage unit 7 because it does not match the positions of the detected targets two or more times during the three parkings. Also, since the position x25 of the target is determined to match when compared with the position x35 of the target detected during the third parking, the number of matches for the position x25 of the target is counted as "1".

[0026] In addition, in the example of FIG. 2, the case where the number of parkings is 3 and the number of matches is 2 has been described, but the number of parkings and the number of matches may be more. For example, the number of parkings may be 5 and the number of matches may be 3. At this time, among the five parkings, the three matching times do not have to be consecutive.

[0027] On the other hand, the registration may be limited to cases where three out of five parking attempts result in a match. In other words, the predetermined condition may be changed to: the location of a temporarily registered target must match the location of a detected target a predetermined number of times or more during a predetermined number of parking attempts to the target parking location after the temporary registration.

[0028] In this way, the target registration unit 15 stores the temporarily registered target's location in the storage unit 7 as the officially registered target's location when the location of the temporarily registered target meets predetermined conditions. The officially registered target's location is set so that it will not be deleted from the storage unit 7, as it is the location of the officially registered target.

[0029] The parking support unit 17 compares the position of the target stored in the memory unit 7 with the position of the target detected by the target detection unit 13 to calculate the relative position of the vehicle with respect to the target parking position. Then, based on the calculated relative position, it calculates a target driving trajectory from the vehicle's current position to the target parking position, and assists in parking by controlling the vehicle to move along the calculated target driving trajectory.

[0030] The parking assist unit 17 outputs control signals to actuators (not shown) to drive the vehicle's steering wheel, accelerator, and brakes. As a result, the parking assist unit 17 controls the steering direction and amount of the vehicle's steering, the accelerator opening, and the braking action of the vehicle's brakes to park the vehicle at the target parking position.

[0031] The parking assistance device 1 is a controller composed of a general-purpose electronic circuit including a microcomputer, microprocessor, and CPU, and peripheral devices such as memory, and has a computer program installed for performing parking assistance processing. Each function of the parking assistance device 1 can be implemented by one or more processing circuits. The processing circuits include, for example, programmed processing devices including electrical circuits, and may also include devices such as application-specific integrated circuits (ASICs) or conventional circuit components arranged to perform the functions described in the embodiments.

[0032] [Parking assistance processing] Next, the parking assistance process performed by the parking assistance device 1 according to this embodiment will be described. Figure 3 is a flowchart showing the processing procedure of the parking assistance process performed by the parking assistance device 1 according to this embodiment.

[0033] As shown in Figure 3, in step S101, the parking position setting unit 11 detects the current position of the vehicle based on the GNSS signal, searches for parking spaces where the vehicle has been parked in the past, and sets a parking space around the vehicle as the target parking position.

[0034] In step S103, the parking position setting unit 11 counts the number of times the target parking position set in step S101 has been parked. Specifically, the parking position setting unit 11 adds 1 to the number of times the target parking position to be parked is located near the target parking position.

[0035] However, if the vehicle parks in the target parking position at night, the number of parking attempts does not need to be counted. At night, it is difficult to detect targets, so targets may not be detected even if they actually exist. If the number of parking attempts is counted in this case, there is a risk that targets that would be useful for parking assistance may be mistakenly deleted, so it is acceptable not to count the number of parking attempts at night.

[0036] In step S105, the object detection unit 13 detects the position of objects in the vicinity of the target parking position when the vehicle parks at the target parking position set in step S101.

[0037] In step S107, the object registration unit 15 compares the position of the object detected in step S105 with the position of a registered object stored in the memory unit 7 to determine whether they match. That is, the object registration unit 15 determines whether the object detected in this parking is an object that has already been registered. If the object positions match, the process proceeds to step S121; otherwise, the process proceeds to step S109.

[0038] In step S109, the object registration unit 15 compares the position of the object detected in step S105 with the position of a temporarily registered object stored in the memory unit 7 to determine whether they match. That is, the object registration unit 15 determines whether the object detected in the current parking is an object that has already been temporarily registered. If the object positions do not match, the process proceeds to step S111; if they do match, the process proceeds to step S113.

[0039] In step S111, the object registration unit 15 stores the position of the object detected in step S105 in the storage unit 7 as the position of a temporarily registered object. That is, the position of the object detected in this parking is determined not to be the object that was officially registered in step S107, nor is it determined to be the object that was temporarily registered in step S109, so it becomes the position of a newly detected object. Therefore, the object registration unit 15 stores the position of the object detected in step S105 in the storage unit 7 as the position of a temporarily registered object.

[0040] In step S113, the object registration unit 15 counts the number of times the temporarily registered object locations match. That is, in step S109, the location of the object detected during the current parking matched the location of the temporarily registered object, so the number of times the temporarily registered object locations match is incremented by 1.

[0041] In step S115, the object registration unit 15 determines whether the location of a temporarily registered object in the vicinity of the target parking position satisfies predetermined conditions. Specifically, the object registration unit 15 determines whether the location of a temporarily registered object has matched the location of a detected object a predetermined number of times or more during a predetermined number of parking sessions performed after the temporary registration. For example, as shown in Figure 2, when parking at the target parking position X, if the object's location x11 matches the detected object two or more times during three parking sessions at the target parking position X after the temporary registration, it is determined that the object's location x11 satisfies the predetermined conditions. If it is determined that the predetermined conditions are met, the process proceeds to step S117; otherwise, the process proceeds to step S119.

[0042] In step S117, the object registration unit 15 changes the location of the object that was determined to meet the predetermined conditions in step S115 from temporary registration to permanent registration. Since the location of the permanently registered object is highly likely to be an object location that is effective for parking assistance, it is set so that it is not deleted from the memory unit 7.

[0043] In step S119, the object registration unit 15 determines whether the object's location, which was determined not to meet the predetermined conditions in step S115, has reached a predetermined number of parking attempts. The temporarily registered object's location is stored in the storage unit 7 even if the predetermined conditions are not met until the predetermined number of parking attempts is reached. For example, as shown in Figure 2, the location is stored in the storage unit 7 until the second parking attempt, even if the predetermined conditions are not met. Therefore, if the predetermined number of parking attempts has not been reached, the system proceeds to step S121 with the temporarily registered object's location stored in the storage unit 7; if the predetermined number of parking attempts has been reached, the system proceeds to step S123.

[0044] In step S121, the target registration unit 15 deletes the location of the target detected in step S105 because it matches a target that has already been registered or temporarily registered. This prevents an increase in the capacity of the storage unit 7, as it does not store any further locations of targets already stored in the storage unit 7.

[0045] In step S123, the object registration unit 15 deletes the locations of temporarily registered objects that have reached a predetermined number of parking attempts and do not meet the predetermined conditions. Since the locations of objects that do not meet the predetermined conditions are unlikely to be effective object locations for parking assistance, they are deleted from the storage unit 7 to prevent an increase in the capacity of the storage unit 7.

[0046] In step S125, the parking support unit 17 performs parking assistance to park the vehicle at the target parking position. Specifically, the parking support unit 17 compares the position of the target stored in the memory unit 7 with the position of the target detected in step S105 to calculate the relative position of the vehicle with respect to the target parking position. Then, based on the calculated relative position, it calculates a target driving trajectory from the vehicle's current position to the target parking position, and controls the actuators to move the vehicle along the calculated target driving trajectory to perform parking assistance.

[0047] At this time, if the position of a temporarily registered target is outside the range that can be detected from the target driving trajectory, the number of parking attempts in step S103 is not counted. If the number of parking attempts is counted even though the target is outside the range that can be detected from the vehicle, there is a risk of mistakenly deleting a target that would be useful for parking assistance, so the number of parking attempts is not counted for targets outside the detection range. In this way, once the vehicle has completed parking at the target parking position, the parking assistance process according to this embodiment is terminated.

[0048] [Effects of the Embodiment] As described in detail above, the parking assistance device 1 according to this embodiment detects the position of an object in the vicinity of the target parking position when the vehicle parks at the target parking position. If the detected object's position differs from the object's position stored in the storage unit 7, the detected object's position is stored in the storage unit 7 as a temporarily registered object's position. Furthermore, only the object's position that satisfies a predetermined condition among the temporarily registered object's positions is stored in the storage unit 7 as a permanently registered object's position. Here, the predetermined condition is that the temporarily registered object's position matches the detected object's position a predetermined number of times or more during a predetermined number of parking attempts to the target parking position after temporary registration. This suppresses the increase in memory capacity, thus eliminating the need for a large-capacity memory and preventing an increase in the device's cost. Furthermore, since only objects effective for parking assistance can be permanently registered and stored in the storage unit 7, the accuracy of parking assistance can be improved.

[0049] Furthermore, in the parking assistance device 1 according to this embodiment, the predetermined condition is that the position of a temporarily registered target matches the position of a detected target for a predetermined number of consecutive times during a predetermined number of parking attempts to the target parking position after the temporary registration. This makes it possible to eliminate unstable targets that are not detected consecutively, thereby further improving the accuracy of parking assistance.

[0050] Furthermore, in the parking assistance device 1 according to this embodiment, if the vehicle parks at the target parking position during the nighttime, the device does not count the vehicle as one of the predetermined number of parking attempts. This prevents the accidental deletion of effective targets for parking assistance, thereby further improving the accuracy of parking assistance.

[0051] Furthermore, in the parking assistance device 1 according to this embodiment, the relative position of the vehicle with respect to the target parking position is calculated by comparing the position of the object stored in the memory unit 7 with the position of the detected object. Then, based on the calculated relative position, a target driving trajectory from the vehicle's current position to the target parking position is calculated, and assistance is provided to move the vehicle along the calculated target driving trajectory. In this way, the parking of the vehicle can be assisted by utilizing the positions of objects around the target parking position where the vehicle was parked in the past.

[0052] Furthermore, in the parking assistance device 1 according to this embodiment, if the position of a temporarily registered target is within a range that cannot be detected from the target driving trajectory, the device will not count the vehicle as a predetermined number of parking attempts even if it parks at the target parking position along the target driving trajectory. This prevents the accidental deletion of targets that would be useful for parking assistance, thereby further improving the accuracy of parking assistance.

[0053] The embodiments described above are merely examples of the present invention. Therefore, the present invention is not limited to the embodiments described above, and various modifications can be made to forms other than those described above, as long as they do not depart from the technical spirit of the present invention, depending on the design and other factors. [Explanation of Symbols]

[0054] 1. Parking assist system 3 sensors 5 GNSS receiver 7 Memory section 11 Parking position setting unit 13 Target detection unit 15. Target Registration Section 17 Parking Support Department 100 Vehicle Systems

Claims

1. A parking assistance method that assists in parking the vehicle by storing the positions of landmarks around a target parking spot where the vehicle has parked in the past in a storage unit, comparing the positions of the landmarks stored in the storage unit with the positions of landmarks detected when the vehicle parks at the target parking spot, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. If the location of the detected target matches the location of the permanently registered target or the location of the temporarily registered target, the location of the detected target is deleted. Among the locations of the temporarily registered targets, the locations of targets that have reached a predetermined number of parking spaces and do not meet the predetermined conditions are deleted. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during the parking at the target parking position performed a predetermined number of times after the temporary registration. A parking assistance method characterized by the following features.

2. A parking assistance method that assists in parking the vehicle by storing the positions of landmarks around a target parking position where the vehicle has parked in the past in a storage unit, comparing the positions of landmarks stored in the storage unit with the positions of landmarks detected when the vehicle parks at the target parking position, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during a predetermined number of parking sessions at the target parking location performed after the temporary registration. A parking assistance method characterized in that, if the vehicle parks at the target parking position during the nighttime, the vehicle does not count the parking at the target parking position as one of the predetermined number of parking times.

3. The parking assistance method according to claim 1 or 2, characterized in that the predetermined condition is that the position of the temporarily registered target coincides with the position of the detected target for a predetermined number of consecutive times or more during a predetermined number of parking sessions to the target parking position performed after the temporary registration.

4. A parking assistance method that assists in parking the vehicle by storing in a memory the positions of landmarks in the vicinity of a target parking position where the vehicle has parked in the past, comparing the positions of landmarks stored in the memory with the positions of landmarks detected when the vehicle parks at the target parking position, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. The system compares the position of the target stored in the memory unit with the position of the detected target to calculate the relative position of the vehicle with respect to the target parking position, calculates a target driving trajectory from the vehicle's current position to the target parking position based on the calculated relative position, and assists in moving the vehicle along the calculated target driving trajectory. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during a predetermined number of parking sessions at the target parking location performed after the temporary registration. A parking assistance method characterized in that, if the position of the temporarily registered target is within a range that cannot be detected from the target driving trajectory, the vehicle does not count the number of parking attempts as a predetermined number of times even if it parks at the target parking position along the target driving trajectory.

5. A parking assistance device comprising a controller that stores the positions of landmarks around a target parking position where the vehicle has parked in the past in a storage unit, compares the positions of landmarks stored in the storage unit with the positions of landmarks detected when the vehicle parks at the target parking position, and assists in parking the vehicle, The aforementioned controller, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. If the location of the detected target matches the location of the permanently registered target or the location of the temporarily registered target, the location of the detected target is deleted. Among the locations of the temporarily registered targets, the locations of targets that have reached a predetermined number of parking spaces and do not meet the predetermined conditions are deleted. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during the parking at the target parking position performed a predetermined number of times after the temporary registration. A parking assistance device characterized by the following features.

6. A parking assistance device comprising a controller that stores in a memory unit the positions of objects in the vicinity of a target parking position where the vehicle has parked in the past, and compares the positions of objects stored in the memory unit with the positions of objects detected when the vehicle parks at the target parking position, thereby assisting in the parking of the vehicle, The aforementioned controller, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during a predetermined number of parking sessions at the target parking location performed after the temporary registration. The controller is a parking assistance device characterized in that, if the time period during which the vehicle parks at the target parking position is at night, the controller does not count the vehicle's parking at the target parking position as one of the predetermined number of parking times.

7. A parking assistance device comprising a controller that stores in a memory unit the positions of objects in the vicinity of a target parking position where the vehicle has parked in the past, and compares the positions of the objects stored in the memory unit with the positions of objects detected when the vehicle parks at the target parking position, thereby assisting in the parking of the vehicle, The aforementioned controller, When the vehicle parks in the target parking position, the position of a target object in the vicinity of the target parking position is detected. If the position of the detected target differs from the position of the target stored in the storage unit, the position of the detected target is stored in the storage unit as the temporarily registered target position. Among the temporarily registered target locations, only the locations of targets that meet the predetermined conditions are stored in the storage unit as permanently registered target locations. The system compares the position of the target stored in the memory unit with the position of the detected target to calculate the relative position of the vehicle with respect to the target parking position, calculates a target driving trajectory from the vehicle's current position to the target parking position based on the calculated relative position, and assists in moving the vehicle along the calculated target driving trajectory. The predetermined condition is that the position of the temporarily registered target matches the position of the detected target a predetermined number of times or more during a predetermined number of parking sessions at the target parking location performed after the temporary registration. The controller is characterized in that, if the position of the temporarily registered target is within a range that cannot be detected from the target driving trajectory, the controller does not count the vehicle parking at the target parking position along the target driving trajectory as one of the predetermined number of parking attempts.

Images