JP2003034206A - Device for supporting parking for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for supporting parking for a vehicle which enables a driver to know in advance whether or not a target track is the one where the vehicle and an obstacle are likely to interfere with each other even when trying to park along the target track from a position where the obstacle has formerly been detected but can not be detected at the time of the parking. SOLUTION: A map for the circumference of the vehicle is made by accumulating information on the obstacle obtained by an ultrasonic sensor 9 while moving the vehicle before parking by a making part 14 for circumferential map, and a candidate for a target parking position is searched and determined by a determination part 15 for the target parking position based on the map. The candidate for the target track leading to the target parking position selected as above is calculated by a calculation part 16 for a target track and a determination part 17 for an interference determines whether there is the possibility of these candidates for the target track interfering with the vehicle. A display form of the target track and the like displayed on a display 11 by an information part 18 is varied according to the result of the determination of the interference. An interference part and the target track and the like are displayed on the display 11 by being superimposed on an image taken by a camera 10 together with the circumferential map and informed to the driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image information of the surrounding conditions of a vehicle as grasped by a CCD camera or the like so that a driver can easily perform an accurate driving operation when trying to park in a parking lot. The present invention relates to a parking assistance device that displays information about obstacles, a target trajectory, etc. on the driver in a superimposed manner.

[0002]

2. Description of the Related Art For example, Japanese Patent Laid-Open No. 10-11427 discloses a vehicle driver that assists driver's driving operation when parked by using an image of the vehicle surroundings captured by a CCD camera mounted on the vehicle.
The one described in Japanese Patent No. 3 is known. In the one described in this publication, parking assistance is provided as follows. First, a desired parking mode is selected from the parallel parking right, the parallel parking left, the parallel parking right, and the parallel parking left by the mode selection switch, and the automatic parking start switch is turned on. According to the voice instructions from the speaker, while pushing the brake pedal lightly to drive the vehicle forward with creep,
Even if the driver does not perform the steering operation, the operation of the steering actuator is controlled so that the steering angle of the vehicle matches the previously stored reference steering angle, and the orientation of the vehicle body is automatically adjusted.

When the vehicle approaches the point where the vehicle should shift from forward to backward, a voice instruction is issued from the speaker, and the driver performs a shift operation to move backward. Even when the vehicle is moving backward, the driver can automatically guide the vehicle to the target parking position without steering the steering wheel by simply stepping on the brake pedal and moving backward by creeping.

During the automatic parking operation, object detection means such as sonar and radar continuously detect the positions of obstacles around the vehicle as the vehicle moves. If an obstacle already exists in the moving path of the own vehicle, or if there is a possibility that an obstacle moving in the moving path of the own vehicle may invade, it will be notified by a speaker or the vehicle will be displayed on the display image. The driver is warned by blinking the part that is likely to interfere with other objects. Further, the automatic braking is actuated at the same time as this alarm to cancel the automatic parking. Further, when the vehicle has a front and rear wheel steering control device, a plurality of movement loci can be set even in the same parking space, and the number of cases in which obstacles can be avoided is increased.

[0005]

In the above-mentioned conventional parking assist system, the image itself around the vehicle and the teaching of the operation stage are displayed on the display, and the object detecting means detects an obstacle as the vehicle moves. Since it was configured to blink the part that seems to interfere only when it is doing, even if it detects the presence of an obstacle before that, such as when entering a parking lot, it will pass through the obstacle and If you start parking after reaching an undetectable position, previously detected obstacles will not be displayed on the expected travel route of the vehicle, etc., and the expected travel route will be set regardless of the obstacles. If the object detection means does not reach the position where the obstacle can be detected again, there is a problem that it is not clear whether or not the parking is possible.

Further, in the above-mentioned conventional parking assistance device,
In a vehicle equipped with a front and rear wheel steering control device, a plurality of movement loci can be set for the same parking lot, but as described above, previously detected obstacles are not stored and the movement locus Since the settings are set independently of obstacles,
Even in this case, there is a problem that the vehicle has to be redone by recognizing that the unfavorable movement locus is selected only after the vehicle is moved along the movement locus and the obstacle can be detected.

According to the present invention, the driver can know the result even if the obstacle cannot be detected at present by utilizing the information of the previously detected obstacle which may be the obstacle of the parking. It is an object of the present invention to provide a vehicle parking assistance device capable of avoiding a target trajectory or a target parking space having an obstacle in advance.

[0008]

According to the present invention of claim 1, a steering angle detecting means for detecting a steering angle, a vehicle speed detecting means for detecting a vehicle speed, and a surrounding obstacle detecting means for detecting an obstacle around the vehicle. A photographing means for photographing the surroundings of the vehicle, a vehicle motion calculating section for calculating a motion of the vehicle on a two-dimensional plane from the steering angle and the vehicle speed, a vehicle motion calculated by the vehicle motion calculating section, and an obstacle. A surrounding map generation unit that generates and stores a two-dimensional surrounding map based on the relative positional relationship to the obstacle obtained by the object detection unit, and parking is possible from the surrounding map generated by the surrounding map generation unit Parking position determination unit that finds a suitable space and determines the target parking position, coordinates of the target trajectory from the current vehicle position to the target parking position and the target vehicle body direction, and target steering for realizing the target trajectory and the target vehicle body direction Target gauge for calculating the angle A vehicle when the vehicle moves on the target trajectory from the calculation unit, the coordinates of the target trajectory calculated by the target trajectory calculation unit, and the position coordinates of the obstacle on the surrounding map generated by the surrounding map generation unit. An interference determination unit that determines whether or not there is interference with an obstacle, an informing unit that notifies the driver of the determination result obtained from the interference determination unit, a surrounding map generated by the surrounding map generation unit, and a target parking position determination An image combining unit that superimposes and combines the target parking position determined by the unit, the target trajectory calculated by the target trajectory calculating unit, and the interference result determined by the interference determining unit with the image obtained from the photographing means, and the image combining unit. And a display unit for displaying the image superposed and combined.

According to the second aspect of the present invention, the target parking position determination unit detects a plurality of target parking position candidates by searching a parking space from the information about the surrounding map stored in the surrounding map generation unit. The target trajectory calculation unit calculates a target trajectory for each target parking position candidate, and the interference determination unit performs an interference determination for each target trajectory.

According to a third aspect of the present invention, the target trajectory calculating section is
A trigger signal generator that outputs a trigger signal, and when the trigger signal is input from the trigger signal generator, the target parking position obtained from the target parking position determiner and the current vehicle obtained from the vehicle motion calculator The target trajectory is calculated from the position.

According to a fourth aspect of the present invention, the target trajectory calculating section is
When calculating the target trajectory from the target parking position obtained from the target parking position determination unit and the current vehicle position obtained from the vehicle motion calculation unit, a plurality of target trajectory candidates are calculated, and the interference determination unit determines each target trajectory candidate. The interference determination is performed for each of the above.

According to the fifth aspect of the present invention, the notification unit changes the display form of the target trajectory calculated by the target trajectory calculation unit according to the determination result of the interference determination unit, and displays it on the display means.

According to the present invention of claim 6, when the vehicle moves on the target track, the interference determining section calculates a track which four corners of the vehicle and six parts of the rear wheel lateral portions of the left and right side surfaces of the vehicle body pass through. Then, the area where the vehicle body passes is calculated from the trajectory, and the obstacle stored in the surrounding map obtained by the surrounding map generation unit is determined by whether the vehicle and the obstacle are present in the area where the vehicle body passes. It is designed to judge the interference of.

According to a seventh aspect of the present invention, when the vehicle is moving on the target trajectory, the interference determining unit determines that the obstacle stored in the surrounding map obtained by the surrounding map generating unit is relative to the vehicle. The obstacle movement region obtained by moving the obstacle is calculated, and the interference between the vehicle and the obstacle is determined depending on whether or not there is a portion where the obstacle movement region and the vehicle body overlap. .

According to the eighth aspect of the present invention, the interference determination section includes at least one of the number of obstacles, the number of line segments representing the contour of the obstacle, and the number of points constituting the line segment representing the contour of the obstacle. The number of obstacles stored in the surrounding map obtained by the surrounding map generator, the number of line segments representing the outline of the obstacle, and the points forming the line segment representing the outline of the obstacle. If the number is equal to or greater than the judgment reference value, the regions where the vehicle body passes are calculated from the four corners of the vehicle body and the six tracks on the left and right sides of the vehicle body on the rear wheel lateral portions, and interference with the vehicle passage region and obstacles is calculated. If it is less than the judgment reference value, when the vehicle moves, the obstacle moving area through which the obstacle passes is calculated and the interference between the obstacle moving area and the vehicle is determined, thereby It is intended to judge interference with an object.

[0016]

According to the first aspect of the present invention, the two-dimensional map of the vehicle surroundings generated by the surrounding map generating unit is stored and stored including the previously detected obstacles, and the interference determining unit determines that the vehicle is on the target trajectory. When moving up, it is judged whether there is interference with the vehicle and the result of this judgment is displayed on the surrounding image along with the target trajectory, etc. Even when making a judgment, it is possible to judge at a glance whether or not the target trajectory is likely to interfere with the obstacle detected before the parking operation is started, and it is possible to avoid redoing the parking operation.

According to the second aspect of the invention, the target parking position determination unit searches for a plurality of target parking position candidates, the target trajectory calculation unit calculates the target trajectory for each target parking position candidate, and the interference determination unit determines each. Since the collision judgment is performed for each target trajectory, the driver can see at a glance whether or not the target trajectories reaching the plurality of target position candidates displayed on the display are likely to interfere with the obstacle, and thus the driver can interfere with the obstacle. It is possible to select in advance a desired target parking position where parking is possible without doing so.

According to the third aspect of the present invention, the target trajectory calculating section generates a trigger signal, for example, a trigger signal generated at each control cycle, or a trigger signal generated by using a switch input when the driver requests, or a vehicle. Since the target trajectory is recalculated according to the input of the trigger signal generated when the vehicle position obtained from the motion calculation unit changes, the target trajectory is newly calculated while changing the vehicle position. The interference determination unit can sequentially check whether or not the target track does not interfere with the obstacle and the vehicle, and it is possible to reliably park the vehicle to the target parking position from a position where the obstacle does not interfere with the vehicle.

According to the invention of claim 4, the target trajectory calculating section calculates a plurality of target trajectory candidates, and the interference determining section makes an interference determination for each target trajectory candidate. Therefore, the driver selects from among the plurality of target trajectory candidates. It is possible to easily select the target trajectory that does not interfere with the obstacle.

According to the fifth aspect of the present invention, whether or not the vehicle can move from the current position to the target parking position without interfering with the obstacle is displayed in the target trajectory display form, for example, line type,
By changing the color and line width to notify the driver, it is possible for the driver to more clearly and quickly know whether or not the target parking position can be reached from the current vehicle position without interfering with obstacles. Become.

According to the sixth aspect of the present invention, when the vehicle moves from the current position to the target parking position, the six locations on the vehicle body (four locations on the vehicle) are determined based on the target trajectory obtained from the target trajectory calculating section.
Even if there are many obstacles, the vehicle determines the interference by calculating the area through which the corners and the rear wheel lateral portions on the left and right sides of the vehicle body pass and checking whether or not an obstacle enters the area. It is possible to more reliably know in a shorter time whether or not the vehicle can reach the target parking position without interfering with the obstacle.

According to the invention of claim 7, when the vehicle moves from the current position to the target parking position, it is drawn by moving the obstacle relative to the vehicle based on the target trajectory obtained from the target trajectory calculating section. Interference judgment is performed by calculating the obstacle movement area and checking whether the vehicle body enters the area, so if there are few obstacles,
It becomes possible to more surely know whether or not the vehicle can reach the target parking position without interfering with the obstacle in a shorter calculation time.

According to the invention of claim 8, when the number of data relating to obstacles stored in the surrounding map obtained from the surrounding map generator is equal to or more than the set judgment reference value, the area through which the vehicle body passes is calculated. , If it is less than the judgment reference value, the area through which the obstacle passes is calculated, and the collision judgment of the vehicle and the obstacle is performed, so a more advantageous interference judgment method can be selected according to the data amount of the detected obstacle, It is possible to make an interference determination in a shorter calculation time.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an entire parking assistance device according to an embodiment. The control unit 1 is composed of a microcomputer, a ROM, a RAM, an interface circuit and the like, and has a role of processing input information from each switch and each sensor described later and calculating data to be output to the display (display means) 11. ing.

The parking operation start switch 2 is operated to operate the parking assist device when the driver has brought the vehicle to a predetermined position with respect to the parking place. When the parking operation start switch 2 is operated,
This output signal is input to the control unit 1, the entire parking assistance device is initialized, and the parking operation assistance is started.

The column parallel selection switch 3 is a switch for the driver to manually select whether to perform reverse parallel parking or reverse parallel parking. The left / right selection switch 4 is a switch for the driver to manually select whether to park in the left space of the host vehicle or in the right space of the host vehicle. These selection signals are input to the control unit 1 by the driver manually switching and selecting these switches 3 and 4.

The target parking position selection switch 5 is for selecting a desired target parking position from among a plurality of target parking position candidates. In the present embodiment, the driver selects one desired target parking position by switch input while looking at the image of the display 11 displaying a plurality of target parking position candidates, for example. Target track selection switch 6
Selects a desired target trajectory from some candidate trajectory by switch input. In this embodiment, the driver selects one desired target trajectory by switch input while looking at the image of the display displaying a plurality of target trajectory candidates, for example.

The steering angle sensor (steering angle detecting means) 7 is constructed by fixing two sets of photo interrupters to the steering column tube with a phase difference therebetween with a slot disk interlocking with the steering wheel interposed therebetween.
Pulses are generated according to the rotation and rotation of the steering wheel and the transmission and blocking of light by the slot disk. This pulse is counted to determine the neutral point and steering angle of the steering wheel operated by the driver, and the steering direction based on the phase difference. By multiplying the obtained steering angle by the steering gear ratio, it can be easily converted into the angle (cutting angle) that the steered wheels (front wheels in this embodiment) are facing.

The vehicle speed sensor (vehicle speed detecting means) 8 rotates the wheel by, for example, arranging a pickup made up of a coil and a permanent magnet with an appropriate gap between teeth of a rotor of a magnetic body that rotates integrally with the wheel. According to the above, a pulse voltage is generated, the time interval of this pulse is measured, and the vehicle speed is obtained from the obtained time interval, the angle per pulse, the tire radius, and the like.

Ultrasonic sensor (surrounding obstacle detecting means) 9
Is a device that uses a piezo-piezoelectric element to emit ultrasonic waves, and when the ultrasonic waves hit an obstacle and are reflected by a receiver that also uses a piezo-piezoelectric element, it is installed around the vehicle. The distance to the obstacle and its direction in the vehicle body coordinate system are detected. The distance to the obstacle is obtained by measuring the time from the emission of ultrasonic waves to the return of the ultrasonic waves and multiplying by the speed of the ultrasonic waves. Here, it is installed at the front end of the vehicle in a direct lateral direction.

The camera (vehicle surroundings hand-drawing) 10 uses, for example, a CCD camera and is installed above the rear part of the vehicle to shoot the rear of the vehicle. The image signal from the camera 10 is input to the control unit 1. The display 11 is, for example, a liquid crystal monitor display used in a so-called back monitor or a navigation device, and the image signal output from the control unit 1 is input to display an image captured by the camera 10. This is to visually provide reference information when the driver parks while moving backward.

FIG. 2 is a functional block diagram of the control unit 1. The predicted trajectory calculation unit 12 calculates the turning radius of the vehicle at that time from the steering angle obtained from the steering angle sensor 7, and draws a specific portion of the vehicle body (for example, a vehicle rear end or a vehicle body beside the rear wheel). Find the orbit.

The vehicle motion calculation unit 13 includes a shift angle (not shown) provided in the transmission for discriminating between the front wheel turning angle obtained from the steering angle sensor 7, the vehicle speed obtained from the vehicle speed sensor 8 and forward or reverse. Based on the shift position obtained from the position sensor, vehicle motion information such as the position of the vehicle and the direction of the vehicle body is obtained from the following state equation, for example. In this case, the initial position is the position at the time when the driver operates the parking operation start switch 2.

[Equation 1] Here, (x, y) is the coordinates of the rear wheel axle center point when the initial position is the origin 0, θ is the direction of the vehicle body, L _wb is the wheel base of the vehicle, and Φ is the front wheel obtained from the steering angle sensor 7. Is the cutting angle.

The surrounding map generating unit 14 adds the vehicle motion information obtained by the vehicle motion calculating unit 13 to the distance and direction to the obstacle obtained by the ultrasonic sensor 9, and considers the position of the obstacle around the vehicle. Map and memorize. As a result, the two-dimensional surrounding map obtained here accumulates and stores the response positional relationship between all the obstacles detected by the ultrasonic sensor 9 and the own vehicle as the vehicle moves,
A wide area map can be obtained. The information detected by the ultrasonic sensor 9 and the like is accumulated and stored until the parking is completed after the parking operation start switch 2 is operated.

The target parking position determination unit 15 selects the parking method selected by the vertical parallel selection switch 3 and the left / right selection switch 4 (for example, one selected from four types of backward parallel parking left and right, backward parallel parking left and right). Referring to, a parking space is searched for in the surrounding map created by the surrounding map generation unit 14, and the target parking position is selected from the searched parking space according to the input of the target parking position selection switch 5. , The coordinates of the target rear wheel axle center point as the target parking position and the target vehicle body direction are determined.

The target trajectory calculation unit 16 includes a target parking position determined by the target parking position determination unit 15 and a vehicle motion calculation unit 13.
A target trajectory is calculated from the current position of the vehicle obtained in step 1 according to a predetermined trajectory generation logic. The details of this trajectory generation logic will be described later. From the coordinates of the target trajectory calculated by the target trajectory calculator 16 and the two-dimensional map around the vehicle obtained from the surrounding map generator 14, the interference determination unit 17 determines the target trajectory from the current vehicle position to the target parking position. When moving along, it is determined whether or not it interferes with an obstacle around the vehicle.

The notification unit 18 changes the display form of the target trajectory according to the determination result of the interference determination unit 17. In this embodiment, for example, a portion of the target trajectory that interferes with the obstacle is displayed as a red thick line, and this line is made to blink. The image composition unit 19
The predicted trajectory calculated by the predicted trajectory calculator 12 and the target trajectory calculator 16 are calculated on the vehicle surroundings image (rear image in this embodiment) captured by the camera 10, and displayed by the notification unit 18. Is superimposed on the determined target trajectory, and the obtained composite image is output to the display 11.

An example of an image displayed on the display 11 is shown in FIG. In the figure, for the own vehicle i,
When the parking operation start switch 2 is turned on, parking assistance is started. Here, it is assumed that the vehicle is a front-wheel steering vehicle, and in this case, the rear-wheel axle center point serves as a reference when calculating the vehicle motion, so the position of the rear-wheel axle center point is set as the origin in the vehicle coordinate system. The front of the vehicle i is the x-axis, and the left side of the rear wheel axle is the y-axis.

Assuming that the vehicle i is now on the rear wheel axle center point c, the vehicle i moves to the rear wheel axle center point d when the vehicle i fits in the parking frame e at the target parking position shown by the broken line. To do. At this time, the vehicle i extends from the current rear-wheel axle center point c to the rear-wheel axle center point d at the target parking position along the target trajectory f of the rear-wheel axle center point indicated by the one-dot chain line in the figure. You will be guided to move.

In the present embodiment, the target trajectory f at the center point of the rear wheel axle is set as "straight line + arc + straight line".
It is necessary when obtaining the target trajectory g drawn by the rear end of the vehicle body of the vehicle i. Since the target trajectory g at the rear end of the vehicle body is displayed on the display 11, it is not always necessary to display the target trajectory f at the center point of the rear axle on the display 11.

The predicted track h is calculated by the predicted track calculation unit 12 and is represented by an arc based on the output of the steering angle sensor 7. When the vehicle moves backward while keeping the steering angle constant, the rear end of the vehicle body i passes. Orbit. The boundary line b indicating an obstacle such as another vehicle k or p is based on the result detected by the ultrasonic sensor 9 at the time of entering the parking lot before the parking operation is started, from the position of the obstacle previously mapped by the surrounding map generation unit 14. It is what I asked for. The part j where the target trajectory g interferes with the boundary line b of the obstacle is judged by the interference judging section 17 and is displayed in a different color with a line thicker than the boundary line b.

A range (display screen frame) a of the image displayed on the display 11 is a portion surrounded by a thick square frame in the figure, and this display screen is photographed by the camera 10 mounted above the rear part of the vehicle body. The coordinates of the converted image are transformed into an image that looks down from above.

Next, an example of the method of calculating the target trajectory by the target trajectory calculator 16 will be described. As a method of this calculation, for example, in the case of reverse parallel parking, which is often used in a known technique, it is performed as follows. The target trajectory calculation unit 16 uses the state quantity x appearing in the previous equation of motion,
y and θ are equations of motion and constraint conditions (for example, maximum steering angle,
The target trajectory is calculated from an initial state (state at the current position) to an end state (state at the end of parking) while satisfying the vehicle speed range, etc., based on certain predetermined conditions.

Here, based on FIGS. 4 and 5 as two kinds of methods (a target trajectory 1 and a target trajectory 0 described later) for calculating a target trajectory in reverse parallel parking, a target trajectory in reverse parallel parking is also used. Two methods (a target trajectory 1 and a target trajectory 0 to be described later) for calculating are described below with reference to FIGS. 6 and 7. In each case, the coordinates of the current rear wheel axle center point D are (x _d , y _d ), and the coordinates of the rear wheel axle center point B at the target parking position are (x _b , y _b ). The coordinate axis in the direction of the vehicle body at this target parking position is x-axis (pointing to the front of the vehicle), y-axis (pointing to the left side of the vehicle), and the trajectory of the rear-wheel axle center point is L ₃ .

First, in the case of calculating the target trajectory 1 in reverse parallel parking, as shown in FIG. 4, first, the direction of the vehicle body axis at the start of the parking operation, that is, the direction of the vehicle body with respect to the x axis is the angle θ _d . In this state, the vehicle straightly retreats along the straight line c ″, then temporarily stops and steers to the maximum steering angle, and rotates the vehicle body clockwise by θ _d while drawing an arc. The vehicle body is parallel to the x-axis in the figure. Then, the vehicle straightly recedes along the straight line c '. Therefore, here, the straight line (Line1) + the arc of the minimum turning radius (Arc1)
+ A combination of straight lines (Line2) is used.

On the other hand, when the target trajectory 0 is calculated in reverse parallel parking, as shown in FIG. 5, the direction of the vehicle body axis at the start of the first parking operation, that is, the straight line c "in which the vehicle body direction is θd with respect to the x axis is shown. After retreating straight along, the vehicle is stopped once and the steering is operated to rotate the vehicle i counterclockwise at the maximum steering angle, then stopped once and the steering is operated in the opposite direction to rotate the vehicle i clockwise at the maximum steering angle. When it comes to a straight line c ′ parallel to the x-axis in the figure, it is stopped and steered to steer to set the steering angle to the neutral position, and the vehicle straightly retreats along the straight line c ′ to the parking position. Therefore, here, the straight line (Line1) + the arc of the minimum radius of rotation (Arc1) + the arc of the minimum radius (Arc2) +
A combination of trajectories such as a straight line (Line 2) is used.

Next, in the case of calculating the target trajectory 1 in the backward parallel parking, as shown in FIG. 6, first, after the vehicle straightly retreats along the straight line c with the direction of the vehicle body parallel to the x-axis, , Stop and then operate the steering wheel to rotate the car body clockwise while drawing an arc at the maximum steering angle, and then reverse when it comes to the intermediate position between the straight line c and the straight line c ′ along the vehicle body axis at the final parking position. Steering operation in the direction to rotate counterclockwise at the maximum steering angle. The parking position is the point at which the vehicle body comes along the straight line c ′ parallel to the x-axis in the figure. Therefore, here, the straight line (Line1) + the arc of the minimum turning radius (Arc1)
+ A combination of orbits of arcs (Arc2) with the minimum turning radius is used.

When calculating the target trajectory 0 in reverse parallel parking, as shown in FIG. 7, the steering operation is performed at the maximum steering angle from the current position at the beginning to rotate the vehicle clockwise, and the straight line c and the final parking position are displayed. When the vehicle comes to an intermediate position with respect to the straight line c'along the vehicle body axis, the steering operation is performed in the opposite direction to rotate counterclockwise at the maximum steering angle. Just when the vehicle body comes to the position along the straight line c ', the vehicle temporarily stops, the steering angle is returned to the neutral position, and the vehicle moves backward along the straight line c'to the target parking position. Therefore, here, a combination of orbits of the minimum turning radius arc (Arc2) + the minimum turning radius arc (Arc1) + straight line (Line1) is used. Note that these trajectories can be easily calculated from the geometrical relationship.

The above processing flow will be described in detail with reference to the general flowchart of FIG. 8 and the subroutine flowcharts of FIGS. 9 to 16. These program processes are repeatedly executed by the microcomputer of the control unit 1 every predetermined control cycle. When the vehicle position obtained from the vehicle motion calculation unit 13 changes, or when the driver requests the change of the target parking position by the switch input of the target parking position selection switch 5 or the like, these vehicle position changes, A trigger signal such as a switch input is input to the target trajectory calculation unit 16 to recalculate the target trajectory. Further, when executing the general flow of FIG. 8, it is assumed that the surrounding map is generated by the surrounding map generating unit 14 in parallel with this.

When the parking operation start switch 2 is operated,
The following processing is started by the control unit 1. In step 100, the control unit 1 reads signals from each sensor and each switch. Details of the reading process here will be described later with reference to FIG. 9. In step 200, the vehicle motion calculation unit 13 causes the steering angle sensor 7
Based on the steering angle from and the vehicle speed from the vehicle speed sensor 8,
The relative position coordinates (x, y) of the vehicle and the direction θ of the vehicle body are calculated according to the movement of the vehicle, with the rear wheel vehicle pongee center point at the time when the parking operation start switch 2 is turned on as the origin. Details of the relative position calculation processing of the vehicle here will be described later with reference to FIG.

In step 300, the target parking position determining unit 15 searches for an appropriate place as a parking space based on the surrounding map generated by the surrounding map generating unit 14, and selects one of the searched target parking position candidates. The driver operates the target parking position selection switch 5 to determine the target parking position, and calculates and sets the orientation of the vehicle body at that time. Details of the target parking position determination processing here will be described later with reference to FIGS. 11 and 12. In step 400, the target trajectory calculation unit 16
Calculates the target trajectory from the current vehicle position to the target parking position set in step 300. Details of the target trajectory calculation processing here will be described later with reference to FIGS. 13 to 15.

In step 500, the interference determination section 17
From the information of the target trajectory calculated in step 400 and the generated surrounding map, it is determined whether the vehicle can move from the current position to the target parking position without interfering with obstacles. Details of the interference determination process here will be described later with reference to FIG. 16.

In step 600, the notification unit 18 changes the line type, the color, the line width of the target trajectory, or any combination thereof, according to the interference determination result determined in step 500. If it exists, the line type, the color, the line width, or a combination thereof of the site where the obstacle interferes is changed.

In step 700, the predicted trajectory calculation unit 12
However, using the steering angle signal obtained from the steering angle sensor 7,
The radius of gyration at that time is calculated, and the expected trajectory of the vehicle body is obtained. In step 800, the image synthesizing unit 19 superimposes and synthesizes the target trajectory subjected to the notification processing in step 600 and the predicted trajectory obtained in step 700 on the captured image of the rear portion captured by the camera 10, and predetermined to the display 11. Transfer in the specified format.

FIG. 9 is a flow chart showing a detailed flow of the sensor signal reading process in step 100 in the general flow chart of FIG. Step 11
At 0, the vehicle motion calculation unit 13 reads the vehicle speed from the vehicle speed sensor 8. In step 120, the predicted trajectory calculation unit 12 and the vehicle motion calculation unit 13 read the steering angle of the steering wheel from the steering angle sensor 7. In step 130, the expected trajectory calculation unit 12 and the vehicle motion calculation unit 13
The front wheel steering angle (front wheel turning angle) is calculated by multiplying the steering angle read at 0 by the steering gear ratio G1.

In step 140, the target parking position determination unit 15 and the target trajectory calculation unit 16 cause the column parallel selection switch 3
Read the selection state of. In step 150, the target parking position determination unit 15 reads the selection state of the left / right selection switch 4. In step 160, the target parking position determination unit 15
Reads the selection state of the target parking position selection switch 5. In step 170, the target trajectory calculation unit 16 reads the selected state of the target trajectory selection switch 6.

FIG. 10 is a flow chart showing a detailed flow of the vehicle motion calculation processing for calculating the position coordinates of the vehicle and the direction of the vehicle body according to the motion of the vehicle in step 200 in the general flow chart of FIG. Step two
In 05, when the vehicle motion calculation unit 13 calculates the vehicle position coordinates and the vehicle body direction, it determines by checking the vehicle position initialization flag as to whether or not these have been initialized. If the vehicle position initialization flag is set, step 24
0, and if reset, go to step 210.

In step 210, the vehicle body position initialization flag is set.
To set. In the following step 215,
Initialize and θ₁= Π / 2. In step 220,
Initialize the x coordinate of the rear wheel axle center point, and₁= 0.
In step 230, the y coordinate of the rear wheel axle center point is initialized,
y₁= 0. Then, in step 240, T_sTo
Sampling time for the vehicle direction one sample before θ₁
And the vehicle speed V and the front wheel turning angle Φ measured in that cycle,
Body orientation θ _TwoAsk for. θ_Two= (T_s・ V / L_wb) ・ Tan Φ + θ₁

In step 250, the x coordinate x of the rear wheel axle center point one sample before is taken with T _s as the sampling time.
₁ , the vehicle body direction θ _1, and the vehicle speed V measured in the cycle, the x coordinate x ₂ of the rear wheel axle center point is obtained. x ₂ = T _s · V · cos θ ₁ + x ₁

In step 260, the y coordinate y of the rear wheel axle center point one sample before is taken with T _s as the sampling time.
₁ , the vehicle body direction θ _1, and the vehicle speed V measured in the cycle, the y coordinate y ₂ of the rear wheel axle center point is obtained. y ₂ = T _s · V · sin θ ₁ + y ₁

At step 270, θ ₁ = θ ₂ and
The new vehicle body orientation obtained in step 240 is used as the vehicle body orientation in this sample. In step 280, x ₁
= A x _2, the x-coordinate of a new rear wheel axle center point obtained in step 250, the vehicle body orientation in the sample. In step 290, y ₁ = y ₂ is set, and the y coordinate of the new rear wheel pongee center point obtained in step 260 is set as the orientation of the vehicle body in this sample.

11 and 12 are flowcharts showing the detailed flow of the target parking position determination processing in step 300 in the general flowchart of FIG. In step 310, the target parking position determination unit 15 determines that the column parallel selection switch 3 is in the selected state, that is, backward parallel parking,
Find out which side of the reverse parallel parking is selected. Step 315 if the reverse parallel parking side is selected
If the backward parallel parking side is selected, the process proceeds to step 320 and the flag flg_p1 is set.
Reset _p1.

In step 325, the left / right selection switch 4
Check the state of, that is, which side is selected, left or right. If the left side is selected, the process proceeds to step 330 to set the flag flg_p2, and if the right side is selected, the process proceeds to step 335 to reset the flag flg_p2. In step 340, the flag flg_p1 is 1
It is determined whether or not (set state), and if 1 then step 3
If not 45, go to step 370. In step 345, it is determined whether flg_p2 is 1. If it is 1, the process proceeds to step 360, and if it is not 1, the process proceeds to step 350. Also in step 370, flg_p2 is 1
Or not. If 1, then step 380
Otherwise, go to step 390.

In step 350, the target parking position determination unit 15 searches for a parking space in which the parallel parking is possible on the right rear side based on the surrounding map generated by the surrounding map generation unit 14. In step 353, the driver selects the target parking position selection switch 5 from the parking space candidates searched in step 350.
To read which target parking position was selected.
In step 355, from the parking space selected in step 353, the coordinates (x _b , y _b ) of the rear wheel axle center point which is the parking target and the direction θ _b of the vehicle body which is the parking target are calculated. The details of the method of determining the target parking position in steps 350 to 355 will be described later.

In step 360, the target parking position determination unit 15 searches for a parking space in which the parallel parking is possible on the left rear side based on the surrounding map generated by the surrounding map generation unit 14. In step 363, the driver selects the target parking position selection switch 5 from the parking space candidates searched in step 360.
To read which target parking position was selected.
In step 365, the coordinates (x _b , y _b ) of the rear wheel axle center point as the parking target and the direction θ _b of the vehicle body as the parking target are calculated from the parking space selected in step 363.

In step 380, the target parking position determination unit 15 searches for a parking space in which left side rear parking is possible based on the surrounding map generated by the surrounding map generation unit 14. In step 383, the driver selects the target parking position selection switch 5 from the parking space candidates searched in step 380.
To read which target parking position was selected.
In step 385, the coordinates (x _b , y _b ) of the rear wheel axle center point as the parking target and the orientation θ _b of the vehicle body as the parking target are calculated from the parking space selected in step 383.

In step 390, the target parking position determination unit 15 searches for a parking space in which the vehicle can be parked in parallel in the rear right direction based on the surrounding map generated by the surrounding map generation unit 14. In step 393, the driver selects the target parking position selection switch 5 from among the parking available space candidates searched in step 390.
To read which target parking position was selected.
In step 395, from the parking space selected in step 393, the coordinates (x _b , y _b ) of the rear wheel axle center point which is the parking target and the direction θ _b of the vehicle body which is the parking target are calculated.

FIG. 13, FIG. 14 and FIG. 15 are flowcharts showing the detailed flow of the target trajectory calculation processing in step 400 in the general flowchart of FIG.
Here, as for the target trajectory, as shown in FIG. 4 and FIG. 5 or FIG. 6 and FIG. It shall be given in combination. Further, the types of target trajectories calculated in the target trajectory calculation are two types, that is, a target trajectory 1 and a target trajectory 0 for parallel and column, respectively. In step 410, the target trajectory calculation unit 16 checks whether the target trajectory selection switch 6 is selecting the target trajectory 1 or the target trajectory 0. If the target trajectory 1 is selected, the process proceeds to step 415, and if the target trajectory 0 is selected, the process proceeds to step 420.

In step 415, the flag flg_p3 is set, and in step 420, the flag flg_p3 is reset. In the following step 430, it is checked whether or not flg_p1 is 1, and if it is 1, the process proceeds to step 435, and if it is not 1, the process proceeds to 440. In step 435, flg_p
Check whether 3 is 1 or not. If 1, go to step 450,
If not 1, the process proceeds to step 460. Also in step 440, it is checked whether or not flg_p3 is 1. If it is 1, the process proceeds to step 470, and if it is not 1, the process proceeds to step 480.

When the backward parallel parking target trajectory 1 is selected, the equation of the straight line Line 1 forming a part of the target trajectory shown in FIG. 4 is calculated in step 450. This straight line coincides with the vehicle body axis at the time when the transmission of the host vehicle i is shifted in the reverse direction. In step 451, the equation of the straight line Line2 forming a part of the target trajectory of FIG. 4 is calculated. This straight line coincides with the vehicle body axis at the time when the own vehicle i completes parking. In step 452, the equation of the arc Arc1 forming a part of the target trajectory in FIG. 4 is calculated. This arc is
The radius is set to be equal to the minimum radius of the center point of the rear axle, which is determined by the maximum front wheel turning angle, and to contact both straight lines Line1 and Line2.

At step 453, the coordinates of the contact point between the straight line line1 and the arc Arc1 are calculated. Step 454
Then, the coordinates of the contact point between the straight line line2 and the arc Arc1 are calculated. At step 455, the straight line L obtained above is obtained.
Data for display is created from ine1, Line2 and arc Arc1. Here, the arc is approximated by a predetermined number of N straight lines and given by a coordinate group representing N + 2 line segments.

When the target track 0 for reverse parallel parking is selected, the equation of the straight line Line1 forming a part of the target track shown in FIG. 5 is calculated in step 460. This straight line coincides with the vehicle body axis at the time when the transmission of the host vehicle i is shifted in the reverse direction. In step 461, the equation of the straight line Line2 forming a part of the target trajectory of FIG. 5 is calculated. This straight line coincides with the vehicle body axis at the time when the own vehicle i completes parking.

At step 462, the equation of the arc Arc2 forming a part of the target trajectory in FIG. 5 is calculated. This arc is set to have a radius equal to the minimum radius of the rear wheel axle center point determined by the maximum front wheel breaking angle, and to be in contact with both the straight line Line2 and a later-described arc Arc1. Step 46
3, the arc Arc that forms a part of the target trajectory in FIG.
Calculate the equation of 1. This arc is set to have a radius equal to the minimum radius of the rear wheel axle center point determined by the maximum front wheel turning angle, and to be in contact with both the straight line Line1 and the arc Arc2.

At step 464, the coordinates of the contact point between the straight line Line2 and the arc Arc2 are calculated. In step 465, the coordinates of the contact point between the straight line Line1 and the arc Arc1 are calculated. At step 466, the arcs Arc1 and Arcs Arc
Calculate the coordinates of the two contact points. Then, in step 467, data for display is created from the straight lines and arcs obtained above. Here, the arc is approximated by a predetermined number of N straight lines and given by N + 2 coordinate groups.

When the target track 1 for backward parallel parking is selected, the equation of the straight line Line1 forming a part of the target track shown in FIG. 6 is calculated in step 470. This straight line coincides with the straight line c of the vehicle body shaft at the time when the transmission of the host vehicle i is shifted in the reverse direction. In step 471, the equation of the arc Arc1 forming part of the target trajectory of FIG. 6 is calculated. This circular arc is composed of a portion from a portion in contact with the straight line Line1 to a position that intersects with a line that passes through an intermediate point between the straight line c and the straight line c'on the vehicle body axis at the target parking position and is parallel to these. In step 472, the arc Arc2 forming a part of the target trajectory of FIG. 6 is calculated. This circular arc should be in contact with the straight line c ′ from the intersection.

At step 473, the coordinates of the contact point between the straight line Line1 and the arc Arc1 are calculated. In step 474, the coordinates of the contact points of the arcs Arc1 and Arc2 are calculated. In step 475, data for display is created from the straight line and the arc obtained above. here,
The arc is approximated by a predetermined N straight lines and given by 2N + 1 coordinate groups.

When the target track 0 for backward parallel parking is selected, the equation of the straight line Line1 forming a part of the target track shown in FIG. 7 is calculated in step 480. This straight line coincides with a straight line c ′ along the vehicle body axis when the host vehicle i is parked at the target parking position. In step 481, the equation of the arc Arc2 forming part of the target trajectory of FIG. 7 is calculated. This circular arc passes from the point of contact with the straight line c on the vehicle body at the time of shifting the transmission in reverse to the intermediate point between this straight line c and the straight line c'on the vehicle body axis at the position where the final parking is completed. It is composed of parts up to the position where it intersects with parallel lines. In step 482, the equation of the arc Arc1 which is a part of the target trajectory in FIG. 7 is calculated. This arc is set so as to contact both the arc Arc2 and the straight line Line1.

At step 483, the coordinates of the contact point between the straight line Line1 and the arc Arc1 are calculated. Step 484
Then, the coordinates of the contact points of the arcs Arc1 and Arc2 are calculated. In step 485, display data is created from the straight lines and arcs obtained above. Here, the arc is approximated by a predetermined number of N straight lines, and given by 2N + 1 coordinate groups.

FIG. 16 is a flow chart showing a detailed flow of the interference judgment processing in step 500 in the general flow of FIG. In step 510, the interference determination unit 17 reads the information on the surrounding map generated by the surrounding map generation unit 14. In step 520, the interference determination unit 17
Reads the target trajectory calculated by the target trajectory calculator 16. In step 530, an area (vehicle passage area) through which the vehicle passes when the vehicle moves from the current vehicle position to the target parking position on the target trajectory is calculated from the target trajectory.

At step 540, whether an obstacle enters the vehicle passage area from the surrounding map information read at step 510 and the vehicle passage area calculated at step 530,
That is, it is determined whether or not they overlap each other, and if they enter, step 550, and if they do not enter, step 560.
Go to. In step 550, the interference determination result flag is set. In step 560, the interference determination result flag is reset. In addition to the interference determination result flag, the interference determination unit 17 obtains coordinate data of a portion where the target trajectory interferes, and coordinates of an interference portion of an obstacle that interferes with the target trajectory.

17 and 18 show an example of map generation in the surrounding map generation section. In the figure, the host vehicle i moves from the right side of the figure to the left side of the figure, and during this period, the ultrasonic sensor 9 laterally attached to the front left of the vehicle body measures the distance on the left side of the vehicle. The case where the driver temporarily stops at the position and the driver tries to park in the backward parallel parking on the left rear side in the vehicle traveling direction is shown. The surrounding map generator 14 uses the ultrasonic sensor 9
In response to the distance measurement output from the vehicle,
80, 90) and the wall 50, the distance measurement results obtained by sequentially sampling these as they move forward in parallel, and the vehicle i
Obstacles are mapped on the two-dimensional plane by sampling points in consideration of the movement amount of.

As shown in FIG. 17, for example, this sampling result is obtained by sampling points 51 to 6 on the wall 50.
Sampling points 71 to 79, 81 to 89, 91 to 99 are obtained for eight and three other vehicles 70, 80 and 90, respectively. In the surrounding map generation unit 14, as shown in FIG. 18, the sampling points are grouped into sampling points 51 to 58, sampling points 59 to 68, sampling points 71 to 79, sampling points 81 to 89, and
And the sampling points 91 to 99 as one block,
Two straight lines 101 and 102 corresponding to the wall 50, and three straight lines 103 corresponding to the other vehicles 70, 80 and 90,
Linear approximation is performed as 104 and 105.

For grouping, for example, if the distance between adjacent points is shorter than a predetermined value, it is determined that they are in the same group. Accordingly, here, the right side surfaces of the parked other vehicles 70, 80, 90 have three lines 103 to 105.
Then, the wall 50 on the left side of these other vehicles has two lines 1
It is represented by 01 and 102.

FIG. 19 shows the target selected by the target parking position determining unit 15 based on the obstacle information in the surrounding map generating unit 14 in addition to the obstacles linearly approximated by the surrounding map generating unit 14 as shown in FIG. Parking position candidate 0 and target parking position candidate 1
And target trajectory candidates 200 and 201 that are respectively calculated by the target trajectory calculation unit 16 and head toward the target parking position candidates.
The image in which the interference site 210 determined by the interference determination unit 17 is superimposed and combined is shown. Note that only the inside of the display frame 100 is displayed on the display 11. The driver is
Looking at the image, the target parking position selection switch 5 is operated to select one of the target parking position candidate 0 and the target parking position candidate 1. Here, although there is the interference portion 210, it is assumed that the target parking position candidate 0 near the own vehicle i is selected and set as the target parking position for the time being.

In FIG. 20, the target trajectory calculating unit 16 uses the target trajectory according to the calculation method shown in FIG. 7 as a plurality of target trajectory candidates for the target parking position (corresponding to the target parking position candidate 0 in FIG. 19) A. The candidate 0 and the target trajectory candidate 1 calculated by the calculation method shown in FIG. 6 are shown. The inside of the display frame 100 is displayed as an image on the display 11. That is, after the target parking position A is selected, the target trajectory calculating unit 16 recalculates 0 as a target trajectory candidate reaching the target parking position in accordance with a trigger signal generated in each control cycle, and further, the target trajectory. Get Candidate 1. The interference determining unit 17 also determines whether or not the target trajectory candidate 1 interferes with an obstacle. Here, the target trajectory candidate 1 is determined to have no interference with the obstacle.

Although the target trajectory candidate 0 and the target trajectory candidate 1 are displayed on the display 11, the display form of the both is different in the notification unit 18 according to the determination result of the interference determination unit 17. For example, the target trajectory candidate 0, which may cause interference, is indicated by a red thin dotted line, and the interference portion 210 is indicated by a thicker red line, whereas the target trajectory 1, which does not cause interference, is indicated by a thick green solid line. Is displayed. The driver views the above display and operates the target track selection switch 6 to select the target track candidate 1. As a result, if the vehicle is moved backward along the target trajectory candidate 1, the vehicle can be parked at the target parking position A without fear of interference.

FIG. 21 is a diagram for explaining a method of judging interference with an obstacle in the interference judging section 17. Here, the walls m, n
Consider a case where the own vehicle i in the middle tries to perform backward parallel parking at the target parking position B in the recessed portion of the wall n. When the vehicle travels on the target trajectory obtained by the target trajectory calculation unit 16, the region through which the vehicle body passes is calculated. Therefore, the four corners of the vehicle are considered in consideration of the parts of the vehicle passing the innermost and outermost sides of the vehicle body. The orbits 301 to 306 through which six positions i _{1 to} i ₄ and the rear wheel lateral portions i ₅ and i _{6 on} the left and right sides of the vehicle body pass are calculated. Note that the points i ₁ 'to i ₆ ' are the target parking positions B
The moving destinations of the respective points i _{1 to} i ₆ when it is assumed that the points have arrived at are shown.

On the other hand, it is calculated from the area where the obstacles (walls m and n) stored in the surrounding map obtained by the surrounding map generator 14 are present and the six orbits 301 to 306 obtained above. A portion 310 where the regions through which the vehicle body passes overlap,
320 is required. The interference determination unit 17 determines the interference between the vehicle and the obstacle depending on whether or not the overlapping portions 310 and 320 are present.

The present embodiment is configured as described above, and uses the vehicle motion calculated by the vehicle motion calculation unit 13 and data obtained by distance measurement of an obstacle while the vehicle is moving by the ultrasonic sensor 9 before the start of parking. Based on the surrounding map generated and accumulated by the surrounding map generating unit 14, the target parking position determining unit 15 determines the target parking position, and the target trajectory to the target parking position calculated by the target trajectory calculating unit 16 is calculated. After the calculation, the interference determination unit 17 determines whether or not it interferes with the position of the obstacle, and displays the target parking position, the target trajectory, and the interference area together with the surrounding map.
Since the superimposition display is performed on the display, even if the obstacle cannot be detected by the ultrasonic sensor 9 at the start of parking, the obstacle detected by the ultrasonic sensor 9 before that is accumulated and stored as a surrounding map, which causes interference. The display 11 can be divided into a target trajectory that is likely to occur and a target trajectory that is not likely to occur. As a result, the driver can easily and quickly avoid the target trajectory that may cause interference and park according to the target trajectory that does not cause the interference, even if the driver does not reach the point where the obstacle can be detected again.

Further, the target trajectory is a region / target trajectory which may interfere with the obstacle in the notification unit 18, and a target trajectory which may not interfere with the obstacle. Since I am trying to change the form,
It is possible to clearly and easily recognize a target parking position and a target trajectory that may interfere with an obstacle.

Instead of the ultrasonic sensor, a radar using laser, microwave, millimeter wave or the like may be used. Further, the camera for photographing the rear of the vehicle is not limited to one mounted on the upper rear portion of the vehicle body, but two cameras may be mounted near the rear end of the vehicle body. By doing so, it is possible to easily obtain an image including the rear end of the vehicle by combining the images captured by these.

In the target trajectory calculating section 16 of the embodiment, the arcs Arc1 and A of the minimum turning radius based on the maximum steering angle are obtained.
Although the trajectory including rc2 and the like is calculated, the present invention is not limited to this when calculating the target trajectory, and an arc having a constant turning radius with an arbitrary constant steering angle can be used.

Further, in the target trajectory calculating section 16 of the embodiment, the target trajectory is repeatedly recalculated according to the trigger signal generated at every predetermined control cycle of the microcomputer, but the driver manually operates it when necessary. Therefore, the trigger signal may be recalculated by using the trigger signal generator that generates the trigger signal. Alternatively, the trigger signal may be output when it is detected that the vehicle has moved a predetermined distance or more. That is, as shown in the upper half of FIG. 22, in order to park at the target parking position A, the target trajectory calculation unit 16 calculates the target trajectory 200, and the interference determination unit 17 uses the target trajectory 200 as an obstacle. Vehicle 70
When it is determined that the line 103 representing the above-mentioned line and the interference position 210 interfere with each other, the notification unit 18 displays the target trajectory 200 by a thin red dotted line and the interference position 210 by a red thick line.
Is displayed in.

As a result, the driver can easily determine that he is in a position not suitable for parking. Therefore, when the vehicle i is moved backward by a predetermined distance or more as shown in the lower half of FIG.
A trigger signal is generated, and the target trajectory calculation unit 16 executes recalculation by the input of this trigger signal, and the target trajectory 220 is obtained. This new target trajectory 220 is used by the interference determination unit 17
However, it is determined that the vehicle can be moved to the target parking position A without hitting the other vehicles 70, 80, etc., and the target trajectory 220 is displayed on the display 11 with a thick green solid line. As a result, the driver can easily reach the optimum position for parking. You can move quickly.

Further, the interference judging section 17 is not limited to the judging method described with reference to FIG. 21, and it is determined whether or not the area through which the vehicle body passes and the line segment representing the contour of the obstacle have intersections, or the six points of the vehicle body. The interference may be determined based on whether or not the trajectory of the line and the line segment representing the contour of the obstacle have an intersection. Alternatively, as shown in FIG. 23, an area (walls n to n ₈ ) drawn by fixing the vehicle i at coordinates and moving an obstacle (here, wall n) relatively, and an area of the vehicle body. The interference determination may be performed depending on whether there is an overlapping portion (340 here). Of course, the area drawn by moving the obstacle relatively and the car body draw 4
Whether or not the line segment of the book (the line segment along the front, rear, and both sides of the vehicle body) has an intersection, the line segment that represents the contour of the relatively moving obstacle and the four line segments that the vehicle body draws It may be possible to judge the interference depending on whether or not there is an intersection.

Further, the interference judgment unit 17 sets the obstacle number judgment reference value (6 in this case) according to the number of parts for calculating the trajectory of the vehicle body (6 in FIG. 21, since there are 6 parts of the vehicle body). If the number of sampling points forming the line segment representing the contour of the obstacle obtained by the ultrasonic sensor 9 is equal to or greater than the obstacle number determination reference value, the interference determination method described with reference to FIG. If it is smaller than the reference value for determining the number of obstacles, the interference determination method described with reference to FIG. 23 is switched to use the interference determination method in a shorter calculation time. In addition, the criterion value for the number of obstacles is
As described above, in addition to being set as a reference value for the number of sampling points forming the line segment representing the contour of the obstacle, it can also be set as the reference value for the number of line segments representing the contour of the obstacle or the number of obstacles. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an entire parking assistance device according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a control unit.

FIG. 3 is an explanatory diagram showing a display example on a display.

FIG. 4 is an explanatory diagram showing a target trajectory calculation procedure during reverse parallel parking.

FIG. 5 is an explanatory view showing another target trajectory calculation procedure during reverse parallel parking.

FIG. 6 is an explanatory diagram showing a target trajectory calculation procedure during reverse parallel parking.

FIG. 7 is an explanatory diagram showing another target trajectory calculation procedure during reverse parallel parking.

FIG. 8 is a general flowchart showing a control flow in the embodiment.

FIG. 9 is a flowchart showing details of a subroutine for detecting a sensor signal.

FIG. 10 is a flowchart showing details of a subroutine for calculating a vehicle position coordinate and a vehicle body orientation.

FIG. 11 is a flowchart showing details of a subroutine for determining a target parking position.

FIG. 12 is a flowchart showing details of a subroutine for determining a target parking position.

FIG. 13 is a flowchart showing details of a subroutine for calculating a target trajectory.

FIG. 14 is a flowchart showing details of a subroutine for calculating a target trajectory.

FIG. 15 is a flowchart showing details of a subroutine for calculating a target trajectory.

FIG. 16 is a flowchart showing the details of a subroutine for determining the interference between an obstacle and a vehicle.

FIG. 17 is an explanatory diagram showing a procedure for generating a surrounding map.

FIG. 18 is an explanatory diagram showing a procedure for generating a surrounding map.

FIG. 19 is an explanatory diagram showing a procedure for determining a target parking position.

FIG. 20 is an explanatory diagram showing a procedure for determining a target trajectory.

FIG. 21 is an explanatory diagram showing a procedure of interference determination.

FIG. 22 is an explanatory diagram showing a procedure for determining a new target trajectory.

FIG. 23 is an explanatory diagram showing another procedure of interference judgment.

[Explanation of symbols]

1 control unit 2 Parking operation start switch 3 Column parallel selection switch 4 Left and right selection sensor 5 Target parking position selection switch 6 Target trajectory selection switch 7 Steering angle sensor (steering angle detection means) 8 Vehicle speed sensor (vehicle speed detection means) 9 Ultrasonic sensor (surrounding obstacle detection means) 10 camera (shooting means) 11 Display (display means) 12 Expected trajectory calculation section 13 Vehicle motion calculator 14 Surrounding map generator 15 Target parking position determination unit 16 Target trajectory calculation unit 17 Interference judgment unit 18 Notification section 19 Image synthesizer

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) B60R 21/00 628 B60R 21/00 628A H04N 7/18 H04N 7/18 J

Claims (8)

[Claims] 1. A steering angle detecting means for detecting a steering angle, a vehicle speed detecting means for detecting a vehicle speed, a surrounding obstacle detecting means for detecting an obstacle around the vehicle, and a photographing means for photographing the periphery of the vehicle. A vehicle motion calculation unit that calculates a motion of the vehicle on a two-dimensional plane from the steering angle and the vehicle speed, a vehicle motion calculated by the vehicle motion calculation unit, and an obstacle obtained by the obstacle detection unit. Based on the relative positional relationship up to, a surrounding map generating unit that generates and stores a two-dimensional surrounding map, finds a parking space from the surrounding map generated by the surrounding map generating unit, and determines a target parking position. A target parking position determination unit that determines the coordinates of the target trajectory from the current vehicle position to the target parking position and a target vehicle body direction, and a target trajectory calculation unit that calculates a target steering angle for realizing the target trajectory and the target vehicle body direction And the From the coordinates of the target trajectory calculated by the target trajectory calculation unit and the position coordinates of the obstacle on the surrounding map generated by the surrounding map generation unit, the vehicle and the obstacle when the vehicle moves on the target trajectory An interference determination unit that determines the possibility of interference, an informing unit that informs the driver of the determination result obtained from the interference determination unit, a surrounding map generated by the surrounding map generation unit, and the target parking position determination unit An image composition unit that superimposes and combines the target parking position determined in step 1, the target trajectory calculated by the target trajectory calculation unit, and the interference result determined by the interference determination unit on the image obtained from the photographing means; A vehicle parking assist device, comprising: a display unit that displays an image that is superimposed and combined by a combining unit. 2. The target parking position determination unit detects a plurality of target parking position candidates by searching a space in which parking is possible from the information about the surrounding map stored in the surrounding map generation unit, and detects the target trajectory. The calculation unit calculates a target trajectory for each of the target parking position candidates, and the interference determination unit makes an interference determination for each target trajectory. Vehicle parking assistance device. 3. The target trajectory calculation section has a trigger signal generation section for outputting a trigger signal, and when the trigger signal is input from the trigger signal generation section, the target parking position determination section obtains the target parking position. 3. The vehicle parking assistance device according to claim 1, wherein the target trajectory is calculated from the position and the current vehicle position obtained by the vehicle motion calculation unit. 4. The target trajectory calculation unit calculates a target trajectory from the target parking position obtained from the target parking position determination unit and the current vehicle position obtained from the vehicle motion calculation unit. 4. The vehicle parking assistance apparatus according to claim 1, wherein a trajectory candidate is calculated, and the interference determination unit is configured to perform an interference determination on each of the target trajectory candidates. 5. The notification unit changes the display form of the target trajectory calculated by the target trajectory calculation unit according to the determination result of the interference determination unit, and displays it on the display means. The vehicle parking assistance device according to claim 1. 6. The trajectory determining section calculates a trajectory through which four corners of the vehicle and six lateral side portions of rear wheels of a vehicle body pass when the vehicle moves on the target trajectory, and the trajectory is calculated. The area where the vehicle body passes from is calculated, and whether the obstacle stored in the surrounding map obtained by the surrounding map generation unit exists in the area where the vehicle body passes or not depends on whether the vehicle interferes with the obstacle. 6. The method according to claim 1, wherein
The vehicle parking assistance device according to any one of 1. 7. The interference determination unit, when the vehicle moves on a target trajectory, the obstacle stored in the surrounding map obtained by the surrounding map generation unit moves relatively to the vehicle. The obstacle moving area obtained by the above is calculated, and the interference of the vehicle and the obstacle is judged depending on whether or not there is a portion where the obstacle moving area and the vehicle body overlap. The vehicle parking assistance device according to any one of 1 to 5. 8. The interference determination unit determines a determination reference value for at least one of the number of obstacles, the number of line segments representing the contour of the obstacle, and the number of points constituting the line segment representing the contour of the obstacle. The number of obstacles stored in the surrounding map obtained by the surrounding map generation unit, the number of line segments representing the contour of the obstacle, and the number of points constituting the line segment representing the contour of the obstacle are If it is equal to or more than the judgment reference value, the region where the vehicle body passes is calculated from the four corners of the vehicle body and the six orbits of the rear wheel lateral portions of the left and right side surfaces of the vehicle body to determine the vehicle passage region and the obstacle interference, When it is less than the judgment reference value, when the vehicle is moving, the obstacle moving area through which the obstacle passes is calculated and the interference between the obstacle moving area and the vehicle is determined, whereby the vehicle and the obstacle are detected. 6. The interference determination according to claim 1 is performed. Vehicle parking assistance device.