Exit assistance device

Abstract

This exit assistance device is configured to: acquire the surrounding conditions of a host vehicle; calculate, on the basis of the current position of the host vehicle and the surrounding conditions of the host vehicle, an exit completion position, which is the position of the host vehicle where the host vehicle completes an exit after having exited from a parking space; and provide a guide to said exit completion position. The calculation of the exit completion position is configured to involve: calculating, on the basis of the current position of the host vehicle and the surrounding conditions of the host vehicle, an exit track which is a travel track of the host vehicle for the purpose of exiting from the current position of the host vehicle to the outside of the parking space; and calculating, as the exit completion position, the first spot in the exit track where the host vehicle is determined to be capable of exiting by moving forward.

Description

Delivery support device

[0001] The present invention relates to a parking assistance device that assists a vehicle in leaving a parking space.

[0002] Conventionally, there have been proposed exit assistance devices that assist in exiting a parking space by displaying camera images of the vehicle's surroundings when the vehicle is exiting a parking space, issuing warnings about people or obstacles in the vicinity, and performing some or all of the user's driving operations on the vehicle side.

[0003] Here, since a user who leaves a parking space will move toward their destination after leaving, there is a desire to know in advance whether their vehicle's position when leaving is appropriate for heading toward their destination. This desire is particularly strong when driving operations are performed automatically on the vehicle side, as it is difficult to correct the direction and position of the vehicle during leaving. For example, Japanese Patent Application Laid-Open No. 2021-194926 discloses a technology as one of the above-mentioned leaving assistance methods, in which, when a vehicle parked in a parking space is automatically left, the surrounding conditions of the vehicle are confirmed, an leaving area is detected on the aisle facing the parking space where the vehicle is parked, and an leaving trajectory from the current position to the leaving area is calculated, and the leaving area and leaving trajectory are presented to the user in advance.

[0004] JP 2021-194926 A (paragraphs 0021-0026)

[0005] However, in the above-mentioned Patent Document 1, the exit area is determined after checking the surrounding conditions of the vehicle and before calculating the exit trajectory. However, the determined exit area does not assume the exit trajectory, and therefore only specifies the approximate area where the vehicle will be located when the vehicle has completed leaving the parking lot. Furthermore, if there are obstacles such as other vehicles around the parking space where the vehicle is parked, the exit trajectory is also limited, making it often difficult to accurately position the vehicle in the previously assumed exit area. As a result, the vehicle may exit the parking lot in a position or direction that is significantly different from the previously announced exit area, causing confusion for the user.

[0006] The present invention has been made to solve the above-mentioned problems in the conventional system, and aims to provide a parking assistance device that can give the user a sense of security by providing more detailed information about the location and direction of the vehicle after it has been parked.

[0007] In order to achieve the above-mentioned object, the exit assistance device of the present invention comprises a situation acquisition means for acquiring the situation around the vehicle, an exit completion position calculation means for calculating an exit completion position, which is the position of the vehicle at which the vehicle will complete its exit when it leaves the parking space, based on the current position of the vehicle and the situation around the vehicle, and a guidance means for guiding the exit completion position, wherein the exit completion position calculation means calculates an exit trajectory, which is the driving trajectory of the vehicle for leaving the parking space from the current position of the vehicle, based on the current position of the vehicle and the situation around the vehicle, and calculates the first point on the exit trajectory at which it is determined that the vehicle can move forward and exit as the exit completion position.

[0008] The leaving assistance device according to the present invention having the above configuration calculates and provides guidance to the user the first point on the leaving trajectory from the parking space at which it is determined that the vehicle can move forward and leave the parking space, thereby providing more detailed guidance to the user regarding the position and direction of the vehicle after leaving the parking space. As a result, it is possible to provide a sense of security to the user who is receiving leaving assistance.

[0009] FIG. 1 is a schematic configuration diagram of a vehicle according to this embodiment. FIG. 2 is a diagram showing an example of the arrangement of ultrasonic sensors on the front of the vehicle. FIG. 3 is a diagram showing an example of the arrangement of ultrasonic sensors on the side of the vehicle. FIG. 4 is a block diagram showing the configuration of an leaving assistance device according to this embodiment. FIG. 5 is a flowchart of a leaving assistance processing program according to this embodiment. FIG. 6 is a diagram showing each detection range in which an obstacle can be detected by an ultrasonic sensor. FIG. 7 is a diagram explaining the detection mode of a forward vehicle. FIG. 8 is a diagram explaining a method for calculating a leaving trajectory and a leaving completion position. FIG. 9 is a diagram showing a guidance screen for the leaving completion position. FIG. 10 is a diagram explaining a case in which the leaving completion position is corrected.

[0010] A detailed description will be given below of a specific embodiment of a leaving-carriage support device according to the present invention with reference to the drawings. First, a vehicle 2 equipped with a leaving-carriage support device 1 according to this embodiment will be described. Figure 1 is a schematic diagram of the vehicle 2 according to this embodiment.

[0011] Here, the vehicle 2 may be, for example, an automobile (internal combustion engine automobile) that uses an internal combustion engine (engine, etc.) as a drive source, an automobile (electric automobile, fuel cell automobile, etc.) that uses an electric motor (motor, etc.) as a drive source, or an automobile that uses both of these as drive sources (hybrid automobile). Furthermore, the vehicle type is not limited, and may be a standard car, a large commercial truck, a bus, construction machinery, or the like. Furthermore, although the following description will be of a four-wheeled automobile, it may also be a two-wheeled or three-wheeled vehicle.

[0012] However, vehicle 2 is a vehicle capable of manual driving, in which the vehicle drives based on the user's driving operation, as well as assisted driving using automatic driving assistance, in which the vehicle drives automatically without the user's driving operation.

[0013] Furthermore, the automated driving assistance may be performed only under specific circumstances, such as when parking or leaving a parking lot, or may be performed for all road sections, or may be performed only while the vehicle is traveling on a specific road section (for example, a highway with a gate (manned or unmanned, toll or free) at the boundary). In the following description, the automated driving section in which the automated driving assistance of the vehicle is performed includes all road sections, including general roads and highways, as well as parking lots. Furthermore, the automated driving assistance is performed only when the user selects to perform the automated driving assistance (for example, by turning on the automated driving start button) and it is determined that the automated driving assistance is possible. On the other hand, the vehicle 2 may be a vehicle that is only capable of assisted driving with automated driving assistance. Alternatively, the automated driving assistance may be performed only when the vehicle is traveling to a parking space when parking (i.e., parking assistance) or when leaving a parking space (i.e., leaving assistance).

[0014] In the vehicle control in the automated driving assistance of this embodiment, for example, the current position of the vehicle, the lane the vehicle is traveling on, and the positions of surrounding obstacles are detected as needed, and vehicle control of the steering, drive source, brakes, etc. is automatically performed so that the vehicle travels along the generated travel trajectory at a speed in accordance with the generated speed plan. In particular, when performing parking assistance or exit assistance, the system uses detection results from sensors and cameras to check the conditions around the vehicle and the parking space, calculates a parking trajectory to the parking space or an exit trajectory from the parking space, and automatically controls the vehicle to park the vehicle into the parking space or exit the parking space along the calculated parking trajectory. When performing exit assistance, the system provides advance guidance on the exit completion position, which is the position of the vehicle at which it will complete exiting the parking space. However, it is also possible to automatically perform only steering operation and manually control the drive source and brakes. Alternatively, it is also possible to provide guidance on the parking trajectory, the exit trajectory, or the vehicle operation, and have the user manually operate the vehicle. Furthermore, as one of the safety devices, the above-mentioned automated driving assistance system has a function of providing assistance to the driver regarding the warning object (for example, a warning by sound, displaying on an in-vehicle display, controlling the deceleration of the vehicle, etc.) when a warning object (for example, a pedestrian) is detected around the vehicle. For example, the system displays on the in-vehicle display the scenery (real scene) around the vehicle captured by a camera installed in the vehicle, and when there is a warning object around the vehicle, a warning image indicating the presence of the warning object is superimposed on the position of the warning object in the scenery, or outputs a warning sound.

[0015] 1, the vehicle 2 has an operation unit 3 that accepts operations from the occupant, a liquid crystal display 4 that displays bird's-eye and overhead images of the vehicle's surroundings and other driving assistance information to the occupant, a speaker 5 that outputs audio guidance related to the driving assistance, a front camera 6, a rear camera 7, and side cameras 8A and 8B for capturing images of the vehicle's surroundings, ultrasonic sensors 9A to 9L that detect obstacles around the vehicle, and a driving assistance ECU (electronic control unit) 10 that performs various calculations based on input information. The driving assistance ECU 10 and other components are collectively referred to as the leaving assistance device 1.

[0016] Each component of the vehicle 2 will be described below. First, the operation unit 3 is arranged, for example, on the front of the steering wheel (also called the steering wheel), and includes an operation button that is operated when starting automatic driving assistance. By operating the operation unit 3, the user can switch between manual driving, in which the vehicle drives based on the user's driving operation, and automatic driving assistance, in which the vehicle drives automatically without the user's driving operation. The operation unit 3 may have a touch panel provided on the front of the liquid crystal display 4. It may also have a microphone and a voice recognition device.

[0017] The liquid crystal display 4 is mounted on the instrument panel of the vehicle 2 and displays bird's-eye and overhead images of the surroundings of the vehicle generated by performing viewpoint conversion and synthesis processing on images captured by the front camera 6, rear camera 7, and side cameras 8A and 8B during execution of the automated driving assistance. In particular, when performing exit assistance, the exit completion position, which is the position of the vehicle when it has completed leaving the parking space, is superimposed on the bird's-eye and overhead images. Furthermore, if there is a warning object such as a pedestrian near the vehicle 2, a warning image indicating the presence of the warning object at the position of the warning object in the bird's-eye and overhead images is also displayed. The liquid crystal display 4 may also be used for a navigation device.

[0018] The speaker 5 is mounted on the instrument panel of the vehicle 2 and outputs voice guidance and warning sounds related to driving assistance. The speaker 5 may also be used for the navigation device.

[0019] The forward camera 6 is an imaging device having a camera using a solid-state imaging element such as a CCD, and is installed, for example, above the front bumper of the vehicle 2 or behind the rearview mirror, with its optical axis facing forward in the direction of travel of the vehicle.

[0020] The rear camera 7 is an imaging device having a camera that also uses a solid-state imaging element such as a CCD, and is installed, for example, near the upper center of the license plate attached to the rear of the vehicle 2, with its optical axis facing toward the rear of the vehicle.

[0021] Furthermore, the side cameras 8A and 8B are imaging devices having cameras that similarly use solid-state imaging elements such as CCDs, and are installed, for example, on the left and right side mirrors of the vehicle 2 with their optical axes facing out to the sides of the vehicle.

[0022] The driving assistance ECU 10 generates bird's-eye and overhead images of the vehicle's surroundings by performing viewpoint conversion and synthesis processing on the images captured by the front camera 6, rear camera 7, and side cameras 8A and 8B. Furthermore, during autonomous driving assistance, the driving assistance ECU 10 performs image recognition processing on the captured images to detect lane lines, parking frame lines, and obstacles (other vehicles, pedestrians, bicycles, walls, guardrails, and other structures) around the vehicle, and performs autonomous driving assistance based on the detection results. In particular, when performing parking assistance or exit assistance, the driving assistance ECU 10 also uses the obstacle detection results from the cameras to confirm the parking space and its surroundings.

[0023] Meanwhile, ultrasonic sensors 9A-9L are positioned at predetermined intervals on the front, rear, and sides of the vehicle 2. They transmit ultrasonic waves as search waves around the vehicle 2 and receive reflected waves from surrounding objects to detect the objects that reflect the search waves. Specifically, they are a type of distance measurement sensor that can measure the distance (measured distance) to the object that reflected the search wave by measuring the time from transmission to reception. Furthermore, ultrasonic sensors 9A-9L are configured to generate output signals (including the distance to the detected object) corresponding to the reception results of the received waves and output them to the control unit. Note that objects detected by ultrasonic sensors 9A-9L include, for example, obstacles that the vehicle 2 must avoid when traveling, such as people, bicycles, other vehicles, and walls, or obstacles that form parking spaces. Note that millimeter-wave sensors or laser sensors may be used as distance measurement sensors instead of ultrasonic sensors.

[0024] The installation position and installation direction of each ultrasonic sensor 9A-9L can be set as appropriate. In this embodiment, in order to detect objects in all directions (forward, backward, left, and right) of the vehicle 2, for example, ultrasonic sensors 9A-9D are installed on the front of the vehicle 2 facing the direction of travel so that the transmission direction of the search wave is forward of the vehicle's direction of travel. Ultrasonic sensors 9E and 9F are installed on the left side of the vehicle 2 facing left so that the transmission direction of the search wave is to the left of the vehicle's direction of travel. Ultrasonic sensors 9G and 9H are installed on the right side of the vehicle 2 facing right so that the transmission direction of the search wave is to the right of the vehicle's direction of travel. Ultrasonic sensors 9I-9L are installed on the rear of the vehicle 2 facing in the opposite direction to the vehicle's direction of travel so that the transmission direction of the search wave is to the rear of the vehicle. The heights of each ultrasonic sensor 9A-9L from the ground surface are approximately the same.

[0025] Taking ultrasonic sensors 9A to 9D as an example, it is desirable that ultrasonic sensors 9A to 9D be installed at different positions around the front bumper or the front grille above the front bumper of vehicle 2, as shown in Figure 2, at equal intervals without bias in the left and right directions, so that detection waves can be transmitted over a wider range in front of the vehicle (i.e., the range in which objects can be detected is wider).

[0026] Specifically, as shown in FIG. 2 , ultrasonic sensor 9A is installed near the left front corner of vehicle 2 with the transmission direction of the probe wave tilted slightly leftward from the direction of travel of vehicle 2 so as to transmit the probe wave to the left front of vehicle 2. Ultrasonic sensor 9B is installed slightly left of the center line of vehicle 2 with the transmission direction of the probe wave tilted toward the direction of travel of the vehicle so as to transmit the probe wave mainly from the front, particularly the left side of vehicle 2. Ultrasonic sensor 9C is installed slightly right of the center line of vehicle 2 with the transmission direction of the probe wave tilted toward the direction of travel of the vehicle so as to transmit the probe wave mainly from the front, particularly the right side of vehicle 2. Ultrasonic sensor 9D is installed near the right front corner of vehicle 2 with the transmission direction of the probe wave tilted slightly rightward from the direction of travel of vehicle 2 so as to transmit the probe wave to the right front of vehicle 2. Ultrasonic sensors 9A and 9D, and ultrasonic sensors 9B and 9C are each arranged symmetrically across the vehicle center line in a plan view. Although not shown, the ultrasonic sensors 9I to 9L on the rear surface of the vehicle 2 are similarly arranged in a vertically symmetrical manner.

[0027] 3, the ultrasonic sensors 9E and 9F on the sides are each installed so as to emit search waves in a direction that intersects at 90 degrees with the direction of travel of the vehicle 2. Since there are fewer sensors installed relative to the range on the sides compared to the front and rear of the vehicle as described above, there are areas where the ultrasonic sensors 9E and 9F cannot directly detect objects. However, in these areas, it is possible to estimate the presence or location of objects from the object detection history of the ultrasonic sensors 9A to 9L. Although not shown, the ultrasonic sensors 9G and 9H on the right side of the vehicle 2 are similarly installed, with left-right symmetry.

[0028] In this embodiment, among the ultrasonic sensors 9A-9L, the ultrasonic sensors 9A-9D on the front of the vehicle 2 and the ultrasonic sensors 9I-9L on the rear of the vehicle 2 are particularly installed in positions where they can receive reflected waves from adjacent sensors as indirect waves, so that by receiving direct and indirect waves as received waves, it is possible to determine not only the distance to an object but also the specific position of the object (its relative position with respect to the vehicle) using triangulation. The ultrasonic sensors 9E-9H on the sides are installed at a distance from each other and therefore cannot receive indirect waves, but as the vehicle moves, it is possible to determine the specific position of the object (its relative position with respect to the vehicle) by triangulation using the measured distance at the previous position, the measured distance at the current position, and the distance traveled between them.

[0029] Meanwhile, the driving assistance ECU 10 is an electronic control unit that performs various processes related to autonomous driving assistance. For example, it constantly detects the vehicle's current position, the lane the vehicle is traveling in, and the positions of surrounding obstacles, and controls the vehicle, such as steering, drive source, and brakes, so that the vehicle travels along the generated travel trajectory at a speed according to the generated speed plan. In particular, when performing parking assistance, the driving assistance ECU 10 uses the detection results of the front camera 6, rear camera 7, side cameras 8A and 8B, and ultrasonic sensors 9A to 9L to check the parking space where the vehicle is to park and its surrounding conditions, calculates a parking trajectory to the parking space, and controls the vehicle to enter the parking space along the calculated parking trajectory and complete parking. Meanwhile, when performing exit assistance, the driving assistance ECU 10 also uses the detection results of the front camera 6, rear camera 7, side cameras 8A and 8B, and ultrasonic sensors 9A to 9L to check the parking space where the vehicle is to leave and its surrounding conditions, calculates an exit trajectory for leaving the parking space, and controls the vehicle to exit the parking space along the calculated exit trajectory and complete the exit. Furthermore, the driving assistance ECU 10 calculates the exit completion position and provides guidance. The LCD display 4 displays the scenery (actual scene) around the vehicle, and if a warning object such as a pedestrian is present around the vehicle, a warning image indicating the presence of the warning object is superimposed on the scenery and a warning sound is output at the position of the warning object within the scenery. The driving assistance ECU 10 is connected to the operation unit 3, LCD display 4, speaker 5, front camera 6, rear camera 7, side cameras 8A and 8B, and ultrasonic sensors 9A to 9L via an in-vehicle network such as a CAN. It is also connected to various sensors mounted on the vehicle 2, such as a vehicle speed sensor, acceleration sensor, gyro sensor, steering sensor, and shift position sensor, as well as an in-vehicle navigation device. The detailed configuration of the driving assistance ECU 10 will be described later.

[0030] In addition, vehicle 2 has basic components as vehicle 2 in addition to the components shown in Figure 1, but we will only explain the configuration related to the control of automatic driving assistance and the control related to that configuration.

[0031] Next, a detailed description will be given of the driving assistance ECU 10 of the leaving assistance device 1 provided in the vehicle 2. Fig. 4 is a block diagram showing the configuration of the leaving assistance device 1 according to this embodiment.

[0032] As shown in FIG. 4 , the driving assistance ECU (electronic control unit) 10 is an electronic control unit that controls the entire leaving assistance device 1. It includes internal storage devices such as a CPU 31, which functions as a calculation device and a control device; a RAM 32, which is used as a working memory when the CPU 31 performs various calculation processes and stores driving trajectory data and the like when the driving trajectory is calculated; a ROM 33, which stores control programs as well as a leaving assistance processing program (see FIG. 5 ), and a flash memory 34, which stores programs read from the ROM 33. The driving assistance ECU 10 includes various means for processing algorithms. For example, a situation acquisition means acquires the situation around the vehicle. A leaving completion position calculation means calculates the leaving completion position, which is the position where the vehicle will complete leaving the parking space based on the current position of the vehicle and the situation around the vehicle. A guidance means provides guidance on the leaving completion position.

[0033] The driving assistance ECU 10 is also connected to various sensors 36 for detecting vehicle behavior, such as a vehicle speed sensor, an acceleration sensor, a gyro sensor, a steering sensor, and a shift position sensor, as well as to each of the vehicle's drive units 37, such as the steering, brake, accelerator, and transmission, and detects the current vehicle behavior based on the detection results of these sensors 36, while controlling each of the drive units 37 to provide automatic driving assistance for the vehicle 2. Specific details of the automatic driving assistance include, for example, constantly detecting the current position of the vehicle, the lane the vehicle is traveling on, and the positions of surrounding obstacles, and controlling the vehicle, such as the steering, drive source, and brakes, so that the vehicle travels along the generated travel trajectory at a speed in accordance with the generated speed plan. However, it is also possible to automatically perform only the steering operation, and manually control the drive source and brakes.

[0034] The flash memory 34 also includes a vehicle information DB 35, which stores various information related to the vehicle 2. For example, the vehicle information DB 35 stores the installation positions (height from the ground and left-right position) and detection axes (optical axes for cameras), overall length, vehicle width, wheelbase, minimum turning radius, etc. of the cameras and ultrasonic sensors 9A to 9L installed on the vehicle 2. This information is input in advance by the occupants or a person from the vehicle manufacturer.

[0035] Next, the leaving assistance processing program executed by the driving assistance ECU 10 in the leaving assistance device 1 having the above configuration will be described with reference to Figure 5. Figure 5 is a flowchart of the leaving assistance processing program according to this embodiment. The leaving assistance processing program is executed after the ACC (accessory power supply) of the vehicle 2 is turned on, and is a program that provides assistance in particular when the vehicle leaves the parking lot as one form of automatic driving assistance. The program shown in the flowchart in Figure 5 below is stored in the RAM 32 or ROM 33 provided in the leaving assistance device 1, and is executed by the CPU 31.

[0036] First, in step (hereinafter abbreviated as S) 1, the CPU 31 determines whether or not to start exit assistance. In particular, the content of the exit assistance in this embodiment is to automatically exit the vehicle from the parking space where the vehicle is parked, and to notify the user of the exit completion position before the vehicle starts to leave. The following description will be given as an example of exit assistance for exiting from parallel parking, which is generally more difficult to exit than perpendicular parking, etc. However, exit assistance can also be provided for exiting from parking styles other than parallel parking.

[0037] For example, the exit assistance may be started when the user operates the operation unit 3 and selects to start the exit assistance, or the exit assistance may be started automatically when the vehicle's ACC power supply (accessory power supply) is turned on.

[0038] If it is determined that delivery assistance should be started (S1: YES), the process proceeds to S2. On the other hand, if it is determined that delivery assistance should not be started (S1: NO), the delivery assistance processing program is terminated.

[0039] In S2, the CPU 31 acquires information about the surroundings of the host vehicle (corresponding to the parking space in which the host vehicle is parked). Specifically, the CPU 31 acquires information about the positions and shapes of obstacles around the host vehicle that need to be avoided when exiting the parking space. Examples of obstacles include other parked vehicles, walls, and pillars. It is desirable to detect not only stationary objects but also moving objects such as pedestrians. Furthermore, in S2, the CPU 31 also acquires information about which side of the roadway the host vehicle is facing, i.e., the direction the host vehicle should exit in parallel parking. While ultrasonic sensors 9A-9L and cameras can be used to detect obstacles, in this embodiment, ultrasonic sensors 9A-9L, which have high detection accuracy, are used to detect obstacles. The CPU 31 continues to detect the surroundings until the exit assistance is completed. If an obstacle approaches the vehicle, a warning is issued using the LCD display 4 and speaker 5.

[0040] Here, when detecting an obstacle using ultrasonic sensors 9A to 9D installed at the front of the vehicle 2 or ultrasonic sensors 9I to 9L installed at the rear, it is possible to identify not only the distance to the obstacle but also the specific position of the obstacle.

[0041] Specifically, by receiving direct and indirect waves as received waves, it is possible to calculate the position coordinates of the reflection point P where the search wave is reflected using triangulation. Direct waves are received waves when the ultrasonic sensor that transmitted the search wave is the same as the ultrasonic sensor that received the wave reflected by the target of the search wave as a received wave. In contrast, indirect waves are received waves when the ultrasonic sensor that transmitted the search wave is different from the ultrasonic sensor that received the wave reflected by the target of the search wave as a received wave. On the other hand, for the ultrasonic sensors 9E-9H installed on the sides, the installation spacing is wide, making it difficult to detect obstacles using triangulation with direct and indirect waves. However, for example, if the vehicle is moving, it is possible to calculate the position coordinates using triangulation based on the distance measurement value, vehicle information (vehicle speed, position coordinates, vehicle direction) at the time the search wave was transmitted to the side of the vehicle, and the same vehicle information at the time the reflected wave was received.

[0042] The CPU 31 then detects obstacles from the calculated point sequence data of the reflection points P. Specifically, the endpoints of the obstacle are determined from the slope and slope change rate of the multiple point sequence, and the position and shape of the obstacle are identified. However, as described above, the ultrasonic sensors 9A-9L transmit ultrasonic waves as search waves around the vehicle 2 and receive reflected waves from objects around the vehicle, thereby detecting objects that reflect the search waves. However, the ultrasonic sensors cannot receive reflected waves from obstacles located farther to the left or right of the detection axis of the ultrasonic sensors (i.e., they have high directivity). Furthermore, as shown in Figures 2 and 3, in this embodiment, multiple ultrasonic sensors are arranged on the vehicle, but the range over which the search waves can be transmitted is limited. Specifically, as shown in Figure 6, the detection ranges 41-52 within which the ultrasonic sensors 9A-9L can detect obstacles are elongated, approximately elliptical ranges. Because the detection ranges 41-52 are limited, for example, as shown in Figure 7, only a portion of the rear of a preceding vehicle 55 located immediately ahead of the vehicle can be detected, making it difficult to identify the entire shape of the rear. Although it is possible to eventually determine the overall shape of the rear of the vehicle as the position and orientation of the vehicle changes after it starts to leave the parking lot, it is expected that only a portion of the shape can be detected at least before the vehicle starts to leave the parking lot or at the time it starts to leave the parking lot.

[0043] Here, when calculating the exit trajectory for parallel parking, it is extremely important to identify the rear shape of the vehicle 55 in front, and in particular, the determination of whether or not the vehicle can move forward on the exit trajectory to exit the parking space is made based on the rear shape of the vehicle 55 in front. In this embodiment, as will be described later, the first point on the exit trajectory at which it is determined that the vehicle can move forward and exit the parking space is defined as the exit completion position and is notified to the user, but before or at the time of starting exit, when the rear shape of the vehicle 55 in front cannot be grasped, the exit completion position cannot be notified.

[0044] Therefore, in S3, the CPU 31 determines whether a leading vehicle 55 is detected in front of the host vehicle based on the surrounding environment of the host vehicle acquired in S2. If a leading vehicle 55 is detected (S3: YES), the CPU 31 regards the vehicle width of the leading vehicle 55 as the same as the vehicle width of the host vehicle (S4). More specifically, as shown in FIG. 7, when the host vehicle is parallel parked on the left side of the road, the CPU 31 regards the distance from the road edge 56 to the right edge of the host vehicle as the same as the distance from the road edge 56 to the right edge of the leading vehicle. On the other hand, when the host vehicle is parallel parked on the right side of the road, the CPU 31 regards the distance from the road edge to the left edge of the host vehicle as the same as the distance from the road edge to the left edge of the leading vehicle. This makes it possible to calculate and provide a relatively accurate exit position, as will be described later, even before or at the time of starting to leave the parking lot, when the rear shape of the leading vehicle 55 cannot be determined. However, since the width of the preceding vehicle 55 is not necessarily the same as the width of the vehicle itself, the actual exit position after leaving the parking lot may differ from the previously notified exit position, and in such cases the guidance content will be corrected when the vehicle reaches the exit position (S13).

[0045] Furthermore, S4 is performed when only a portion of the rear surface of the preceding vehicle 55 can be detected and the overall shape of the rear surface cannot be identified, and if the overall shape of the rear surface can be identified by the ultrasonic sensors 9A to 9L before or at the time when the host vehicle starts to leave the garage, the process of S4 is not necessary. Furthermore, if the preceding vehicle 55 is not detected (S3: NO), the process proceeds to S5.

[0046] In S5, the CPU 31 calculates the exit trajectory, which is the driving trajectory for exiting the parking space in which the vehicle is currently parked, using the surrounding conditions acquired in S2 (including the vehicle ahead whose vehicle width was estimated in S4), the initial steering angle, and the vehicle information stored in the vehicle information DB 35 (the vehicle's length, width, minimum turning radius, etc.).

[0047] While various trajectories are conceivable for exiting a parallel parking space, the following trajectory is used in this embodiment: (1) The vehicle moves back as far as possible from the initial parking position without coming into contact with the vehicle 57 behind. (2) After turning to the maximum extent in the exit direction (to the right if exiting to the right), the vehicle moves forward as far as possible without coming into contact with the vehicle 55 ahead. The determination of contact with the vehicle ahead 55 is made based on the vehicle width of the vehicle ahead 55 estimated in S4. (3) After turning to the maximum extent in the opposite direction to (2), the vehicle moves back as far as possible without coming into contact with the vehicle behind 57 or obstacles (guardrails or curbs) on the road edge 56. (4) Thereafter, the vehicle's direction is changed by repeatedly performing the above-mentioned (2) and (3) back-and-forth movements. Once it is determined that the vehicle can move forward and exit the parking space without coming into contact with the vehicle ahead 55, the vehicle moves forward and exits the parking space. The determination as to whether or not the vehicle can move forward to leave the parking lot is made based on the vehicle width of the vehicle ahead 55 estimated in S4, as in (2).

[0048] The area within which the vehicle can move when making the above-mentioned (2) and (3) turns is an area obtained by subtracting a safety margin to avoid contact with obstacles around the parking space (vehicles ahead, vehicles behind, guardrails, curbs, etc.).The turning trajectory is calculated assuming that the vehicle moves and turns only within the movement guidance area.

[0049] As a result, the exit trajectory calculated in S5 is composed of a combination of a reverse trajectory 61, which moves backward from the initial parking position, a turning trajectory 62, which gradually changes the vehicle's direction by repeatedly turning (the number of turns varies depending on the surrounding conditions), and a forward trajectory 63, which moves forward and exits the parking space after it is determined that the vehicle can move forward and exit the parking space by turning.Then, the vehicle 2 can exit the parking space by traveling along the exit trajectory.However, the exit trajectory calculated in S5 is a hypothetical exit trajectory assumed before the exit assistance started, and the actual exit trajectory may differ from the exit trajectory calculated in S5.

[0050] Then, in S6, the CPU 31 determines the exit completion position based on the exit trajectory calculated in S5. The exit completion position is the first point on the exit trajectory at which it is determined that the vehicle can move forward and exit the parking space. For example, in the exit trajectory shown in FIG. 9, the exit completion position corresponds to the point at which the shift position is last switched from "R" to "D" (the point at which the steering for changing direction is completed and the vehicle finally switches from reverse to forward). The exit completion position is information that specifies not only the vehicle's location but also the vehicle's direction at that time. The exit completion position may be the first point at which it is determined that the vehicle can move forward and exit the parking space, including a turning state where the steering angle is not in the neutral position, or the first point at which it is determined that the vehicle can leave the parking space by moving forward (straight) with the steering angle in the neutral position. Completing the exit with the steering angle in the neutral position can increase the driver's sense of security when the operation is handed over to the driver at the exit completion position.

[0051] Next, in S7, the CPU 31 guides the user by displaying the exit completion position estimated in S6 on the LCD display 4. For example, in an overhead image of the area around the vehicle displayed on the LCD display 4, a frame image surrounding the vehicle, which is assumed to be at the exit completion position, is displayed. The frame image also indicates the orientation (exit angle) of the vehicle at the exit completion position. For example, FIG. 9 is an example of an overhead image 71 displaying a frame image 70 indicating the exit completion position. The example shown in FIG. 9 illustrates a case where a parallel-parked vehicle is being pulled to the right, and the frame image 70 indicating the exit completion position is displayed partially overlapping with a vehicle image 72 indicating the current position of the vehicle in the overhead image. This allows the user viewing the overhead image 71 to grasp the position and orientation of the vehicle that can be pulled forward from the current parking space. The method for generating the overhead image 71 is well known and will not be described in detail here, but the overhead image 71 is generated by performing viewpoint conversion and synthesis processing on the images captured by the front camera 6, rear camera 7, and side cameras 8A and 8B. A warning image may be displayed on a bird's-eye view image viewed from diagonally below, rather than on the overhead image. Furthermore, in addition to the exit completion position, an arrow indicating the exit track or the exit direction may also be displayed.

[0052] Furthermore, the frame image 70, the overhead image 71, and the vehicle image 72 continue to be displayed on the LCD display 4 at least until the exit assistance is completed. When the exit assistance is subsequently started, the displayed overhead image 71 changes in accordance with the displacement of the vehicle's current position, and the position of the vehicle image 72 in the overhead image 71 also changes. Meanwhile, the position of the frame image 70 in the overhead image 71 does not generally change until the vehicle satisfies the exit condition of S11 (described below) (it is determined that the vehicle can move forward and exit the parking space). This makes it possible to prevent the frame image 70 on the screen from being frequently updated (display flickering).

[0053] Thereafter, in S8, the CPU 31 starts the leaving assistance in accordance with the leaving trajectory calculated in S5. Specifically, the current position of the vehicle is detected at any time, and vehicle control such as steering, drive source, and braking is automatically performed so that the vehicle travels at a specified speed along the generated leaving trajectory. The shift position is also automatically switched. Also, while the leaving assistance is being performed, the ultrasonic sensors 9A to 9L are continuously used to obtain information about the surrounding conditions, as in S2.

[0054] However, when the vehicle moves along the departure trajectory, only the steering operation may be performed automatically, and the drive source and brakes may be controlled manually. Alternatively, the vehicle may be moved manually rather than automatically. In this case, the departure assistance may include displaying the departure completion position and departure trajectory on the LCD display 4, and providing voice guidance on the timing to turn the steering wheel.

[0055] Thereafter, in S9, the CPU 31 determines whether new surrounding conditions have been acquired using the ultrasonic sensors 9A to 9L after the start of the parking assistance. Specifically, this applies when a new obstacle is detected in a position that cannot be grasped from the host vehicle parked in the parking space, or when the exact shape of an obstacle whose exact shape is difficult to identify from the host vehicle parked in the parking space is detected.

[0056] If it is determined that new surrounding conditions have been acquired using the ultrasonic sensors 9A to 9L after the start of the leaving assistance (S9: YES), the process proceeds to S10. On the other hand, if it is determined that new surrounding conditions have not been acquired (S9: NO), the process proceeds to S11.

[0057] In S10, the CPU 31 corrects the departure trajectory as necessary based on the surrounding conditions newly acquired using the ultrasonic sensors 9A-9L after the start of the departure assistance. Specifically, the departure trajectory is corrected when a new obstacle is detected in a position that cannot be grasped from the host vehicle while parked in the parking space, and it is determined that the current departure trajectory may result in contact with the obstacle, or when the accurate shape of an obstacle whose exact shape is difficult to identify from the host vehicle while parked in the parking space is detected, and it is determined that the current departure trajectory may result in contact with the obstacle. In particular, the rear shape of the leading vehicle 55 located in front of the host vehicle may be detected to be different from the shape estimated in S4 before the departure assistance was started. In such cases, the departure trajectory is corrected. Note that if the departure trajectory is corrected, the current departure trajectory is replaced with the corrected departure trajectory, and thereafter, departure assistance is performed according to the corrected departure trajectory.

[0058] Then, in S11, the CPU 31 determines whether the vehicle can move forward from its current position and exit the parking space, i.e., whether the vehicle has reached the exit completion position. If the exit trajectory has been corrected in S10, the current position of the vehicle that satisfies the determination condition in S11 does not necessarily match the exit completion position set in S6. In that case, the current position and direction of the vehicle will be updated to the new exit completion position in S11, which will be described later.

[0059] The timing at which the determination condition of S11 is satisfied is not only the timing when the shift position is switched from "R" to "D," i.e., the timing at which one turning operation to correct the vehicle heading is completed, but also the timing during forward movement. The determination condition of S11 is satisfied during forward movement when the exit trajectory is corrected during forward movement, and the state where it is impossible to exit the parking space by moving forward from the vehicle's current position changes to a state where it is possible. On the other hand, when the vehicle is reversing (during reversing), the determination is not YES even if the condition of S11 is satisfied. In other words, even if it is determined that the vehicle can exit the parking space by moving forward from that point while reversing, the current position of the vehicle is not determined to be the exit completion position, but the current position of the vehicle at the time the shift position is subsequently switched to "D" becomes the exit completion position.

[0060] If it is determined that the vehicle can move forward from its current position to exit the parking space (S11: YES), and if the current position and direction of the vehicle differ from the exit completion position calculated in S6 (which also corresponds to the currently guided exit completion position), the current position and direction of the vehicle are updated as a new exit completion position (S12). If the current position and direction of the vehicle match the exit completion position calculated in S6, the processes of S12 and S13 are omitted. On the other hand, if it is determined that the vehicle cannot move forward from its current position to exit the parking space (S11: NO), the process returns to S9 and continues to provide exit assistance.

[0061] Next, in S13, the CPU 31 notifies the user by displaying the leaving completion position updated in S12 on the liquid crystal display 4. For example, as shown in Fig. 10, the frame image 70 displayed on the liquid crystal display 4 in S7 is corrected to the correct leaving completion position, i.e., to a position that surrounds the current vehicle. As a result, even if the leaving completion position notified in advance differs from the actual leaving completion position, the user can finally grasp the correct leaving completion position, and further understand that the current position of the vehicle is the leaving completion position (i.e., the vehicle can leave by moving forward from its current position).

[0062] Next, in S14, the CPU 31 determines whether or not the vehicle has completed leaving the parking space. Specifically, when it is determined that the vehicle has moved forward from the leaving completion position along the leaving trajectory and completely exited the parking space, it is determined that the vehicle has completed leaving the parking space.

[0063] If it is determined that the vehicle has been taken out of the garage (S14: YES), the take-out assistance processing program is terminated. On the other hand, if it is determined that the vehicle has not been taken out of the garage (S14: NO), the take-out assistance continues.

[0064] As described above in detail, the leaving assistance device 1 and the computer program executed by the leaving assistance device 1 according to this embodiment acquire the situation around the vehicle (S2), calculate the exit completion position, which is the position where the vehicle will complete leaving if it leaves the parking space, based on the current position of the vehicle and the situation around the vehicle (S5, S6), and provide guidance on the exit completion position (S7). Meanwhile, in calculating the exit completion position, the leaving trajectory, which is the traveling trajectory of the vehicle for leaving the parking space from the current position of the vehicle, is calculated based on the current position of the vehicle and the situation around the vehicle (S5), and the first point on the leaving trajectory at which it is determined that the vehicle can move forward and leave the parking space, is calculated as the exit completion position (S6). This makes it possible to provide the user with more detailed guidance on the location and direction of the vehicle after leaving the parking space. As a result, it is possible to provide a sense of security to the user who is receiving the leaving assistance. Furthermore, the system provides guidance based on the calculated exit completion position before or at the time the vehicle starts to leave the parking lot (S7), and does not update the guided exit completion position even if the exit trajectory changes after the vehicle starts to leave the parking lot. If, when the vehicle is moving forward, it is determined that the vehicle can leave the parking lot by moving forward from that point and the vehicle's current position differs from the guided exit completion position, the guided exit completion position is updated to the vehicle's current position (S12, S13). This prevents a flickering guidance display in which the guided exit completion position is updated every time the vehicle moves slightly. Furthermore, if, when the vehicle is reversing, it is determined that the vehicle can leave the parking lot by moving forward from that point and the vehicle's current position differs from the guided exit completion position, the guided exit completion position is not updated, thereby preventing the vehicle's current position from reversing away from the updated exit completion position. Furthermore, when another vehicle parked in front of the vehicle is located, the situation acquisition means assumes that the width of the other vehicle is the same as that of the vehicle itself (S4), so that even if the shape of the other vehicle located in front cannot be accurately identified, it is possible to calculate the exit position with a certain degree of accuracy.

[0065] The present invention is not limited to the above embodiment, and various improvements and modifications are possible without departing from the spirit and scope of the present invention. For example, although the present embodiment shows a case where the vehicle exits a parking space by moving forward in parallel parking, it is also possible to use an exit trajectory where the vehicle exits a parking space by moving backward. In that case, in S4, the vehicle width of the vehicle behind the vehicle, rather than the vehicle in front of the vehicle, is considered to be the same as the vehicle width of the vehicle.

[0066] In addition, although this embodiment describes the case where exit assistance is provided from a parallel parking position, it is also possible to provide similar exit assistance for exiting from a parking position other than parallel parking. When exiting from a parallel parking position with the vehicle facing backwards, the initial parking position is generally the exit completion position, but if, for example, the aisle facing the parking space is narrow and it is not possible to exit by simply moving forward, a position other than the initial parking position may be the exit completion position.

[0067] In this embodiment, the leaving assistance processing program (FIG. 5) is executed by the driving assistance ECU 10 of the leaving assistance device 1, but the executing entity can be changed as appropriate. For example, the leaving assistance processing program may be executed by the control unit of the liquid crystal display 4, the vehicle control ECU, the control unit of the navigation device, or other in-vehicle device.

[0068] [Summary of this embodiment] This embodiment has at least the following configuration: A situation acquisition means (10) that acquires the situation around the host vehicle (2), an exit completion position calculation means (10) that calculates an exit completion position, which is the position of the host vehicle at which exit is completed when the host vehicle leaves a parking space, based on the current position of the host vehicle and the situation around the host vehicle, and a guidance means (10) that provides guidance on the exit completion position, wherein the exit completion position calculation means calculates an exit trajectory (61 to 63), which is the traveling trajectory of the host vehicle for leaving the parking space from the current position of the host vehicle, based on the current position of the host vehicle and the situation around the host vehicle, and calculates the first point on the exit trajectory at which it is determined that the host vehicle can move forward and exit as the exit completion position.

[0069] With this configuration, the first point on the exit trajectory from the parking space at which it is determined that the vehicle can move forward and exit the parking space is calculated as the exit completion position and guidance is provided, so that the user can be given more detailed guidance on the position and direction of the vehicle after exiting, which makes it possible to provide a sense of security to the user who is receiving the exit assistance.

[0070] In addition, in this embodiment, the guidance means (10) provides guidance on the completion of release position calculated by the completion of release position calculation means (10) before the vehicle (2) starts to leave or at the time when the vehicle starts to leave, and after the vehicle starts to leave, the guidance completion of release position is not updated even if the release trajectory (61 to 63) changes, and when the vehicle is moving forward, if it is determined that the vehicle can leave by moving forward from that point and the current position of the vehicle is different from the guidance completion of release position, the guidance completion of release position is preferably updated to the current position of the vehicle.

[0071] This configuration can prevent a flickering guidance display in which the guided exit position is updated every time the vehicle moves slightly.

[0072] In addition, in this embodiment, when it is determined that the vehicle (2) can leave the parking lot by moving forward from that point when the vehicle (2) is reversing, the guidance means (10) preferably does not update the guided exit completion position even if the current position of the vehicle differs from the guided exit completion position.

[0073] This configuration can prevent the current position of the vehicle from moving back away from the updated exit completion position.

[0074] In addition, in this embodiment, when another vehicle (55) parked in front of the host vehicle (2) is located, the situation acquisition means (10) preferably regards the vehicle width of the other vehicle as being the same as the vehicle width of the host vehicle.

[0075] With this configuration, even if the shape of the vehicle ahead cannot be accurately identified, it is possible to calculate the exit completion position with a certain degree of accuracy.

[0076] 1... Depot leaving assistance device, 2... Vehicle, 3... Operation unit, 4... Liquid crystal display, 6... Front camera, 7... Rear camera, 8A, 8B... Side cameras, 9A to 9L... Ultrasonic sensors, 10... Driving assistance ECU, 55... Front vehicle, 61... Reverse trajectory, 62... Turning trajectory, 63... Forward trajectory, 70... Frame image, 71... Bird's-eye view image

Claims

1. A departure assistance device comprising: a situation acquisition means for acquiring the situation around the host vehicle; an exit completion position calculation means for calculating an exit completion position, which is the position of the host vehicle at which the vehicle will complete leaving the parking space when it leaves the parking space, based on the current position of the host vehicle and the situation around the host vehicle; and a guidance means for providing guidance on the exit completion position, wherein the exit completion position calculation means calculates an exit trajectory, which is the traveling trajectory of the host vehicle for leaving the parking space from the current position of the host vehicle, based on the current position of the host vehicle and the situation around the host vehicle, and calculates the first point on the exit trajectory at which it is determined that the host vehicle can move forward and exit as the exit completion position.

2. The delivery assistance device of claim 1, wherein the guidance means provides guidance on the delivery completion position calculated by the delivery completion position calculation means before the vehicle starts to leave or at the time when the vehicle starts to leave, does not update the guided delivery completion position even if the delivery trajectory changes after the vehicle starts to leave, and updates the guided delivery completion position to the current position of the vehicle when it is determined that the vehicle can leave by moving forward from that point and the current position of the vehicle is different from the guided delivery completion position.

3. The delivery assistance device according to claim 2, wherein the guidance means does not update the delivery completion position that is guided when it is determined that the vehicle can be delivered by moving forward from that point when the vehicle is reversing, even if the current position of the vehicle differs from the delivery completion position that is guided.

4. A parking assistance device as described in any one of claims 1 to 3, wherein the situation acquisition means, when another vehicle parked in front of the vehicle, regards the vehicle width of the other vehicle as being the same as the vehicle width of the vehicle.

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