JP2018118593A - Parking support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a parking support device which keeps a vehicle from being dislocated in the lateral direction when making the vehicle travel backward toward a target parking frame.SOLUTION: A parking support device 1 that sets a passage for traveling backward into a target parking frame present on a side of a vehicle 2 by making the vehicle 2 travel forward for parking in the target parking frame and switching an advancing direction of the vehicle 2, comprises a step information detection unit 12 detecting information on a step extending along a direction substantially orthogonal to the center line of the target parking frame and formed on an advance passage to the target parking frame, and a virtual parking frame setting unit 16 that, when information on a step has been detected, sets a virtual parking frame that has a center line coincident with an extension line of the center line of the target parking frame and guides the vehicle by forward travel to a position opposite the target parking frame across the extension line of the center line of the vehicle 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a parking assistance device.

  Conventionally, when there is a step in the route on which the vehicle is traveling backward, it is necessary to increase the driving torque of the wheel when the vehicle gets over the step. A vehicle travel support apparatus that increases driving torque to assist vehicle travel includes a torque increase unit that increases the drive torque, a step detection unit that detects a step on the road surface in the traveling direction of the vehicle, and a torque increase unit. There is a switch unit that switches between a first state in which the operation is allowed and a second state in which the operation of the torque-up unit is suppressed. The switching unit forms the first state when a step is detected by the step detection unit (for example, Patent Document 1).

JP 2008-201270

  By the way, in a general parking assistance device that performs parallel parking, in order to guide a vehicle that is traveling on a road surface ahead of the target parking frame backward to the target parking frame, the vehicle moves forward so as to pass in front of the target parking frame. Parking control is performed in which the vehicle travels backward so as to make a turn after traveling to guide the vehicle to the target parking frame. Here, if there is a step in the reverse travel route, it is necessary to increase the driving torque of the wheels. If this parking assist control is performed in a state where the drive torque is increased, a certain amount of torque increase is required to overcome the step while turning the vehicle, and the vehicle speed is set higher than usual. Need to be high. While turning, the vehicle enters the target parking frame at an angle with respect to the step and crosses the step. As a result, a shift occurs in the timing when the left and right wheels ride on the steps, and the sideslip of the wheels is likely to occur. For this reason, a lateral shift tends to occur with respect to the trajectory drawn by the vehicle traveling backward.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a parking assist device in which the vehicle is difficult to shift in the lateral direction when the vehicle travels backward toward the target parking frame.

  The parking assist device according to the present invention travels forward in order to park a vehicle in a target parking frame that exists on the side of the vehicle, switches a traveling direction of the vehicle, and travels backward in the target parking frame. And detecting information relating to a step extending along a direction substantially orthogonal to the center line of the target parking frame and formed on the approach path to the target parking frame. A step information detecting unit, and a center line that coincides with an extension of the center line of the target parking frame when the information about the step is detected by the step information detecting unit, and an extension line of the center line of the vehicle A virtual parking frame setting unit that sets a virtual parking frame that guides the vehicle in forward travel to a position facing the target parking frame across the vehicle, and at least the turning angle of the vehicle to the virtual parking frame is set to a maximum turning angle In the maintained state, the temporary A forward travel path setting unit configured to set an arc-shaped forward travel path that turns the vehicle in forward travel and leads to the virtual parking frame until the center line of the vehicle coincides with a center line of the parking frame; and the forward travel A forward travel control unit that causes the vehicle to travel forward along the forward travel route set by the route setting unit, and stops the vehicle at a position where the center line of the vehicle coincides with a center line of the virtual parking frame; A reverse travel route setting unit configured to set a linear reverse travel route that guides the vehicle straight from the virtual parking frame along the center line of the target parking frame to the target parking frame. A reverse travel control unit that causes the vehicle to travel backward along the reverse travel route set by the route setting unit and stops the vehicle on the target parking frame.

  According to the parking assist device according to the present invention configured as described above, the vehicle is caused to travel forward to a virtual parking frame that can travel backward and straight with respect to the target parking frame before the vehicle travels backward toward the target parking frame. A route can be set. Thereby, if the vehicle led to the virtual parking frame is caused to travel straight forward and backward with respect to the target parking frame, it is possible to prevent or suppress lateral displacement by causing the left and right wheels to ride on the step at the same time.

It is a functional block diagram which shows the function structure of the parking assistance apparatus which concerns on Example 1 of this invention. FIG. 2 is a hardware block diagram illustrating a specific device configuration of the parking assistance device according to the first embodiment. It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 1). It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 2). It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 3). It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 4). It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 5). It is a figure explaining the outline | summary of the automatic parking performed by the parking assistance apparatus which concerns on Example 1 (the 6). It is a flowchart which shows the flow of the whole process performed with the parking assistance apparatus which concerns on Example 1 (the 1). It is a flowchart which shows the flow of the whole process performed with the parking assistance apparatus which concerns on Example 1 (the 2). It is a figure explaining the two-wheel model which replaced the four-wheeled vehicle of Example 1 with the two-wheeled vehicle.

  Hereinafter, specific embodiments of a parking assistance device according to the present invention will be described with reference to the drawings.

  In this embodiment, the parking assist device of the present invention is mounted on a vehicle to constitute a system that supports the parking operation of the vehicle.

(Description of the configuration of the embodiment)
First, the configuration of the present apparatus will be described with reference to FIGS. 1 and 2.

  The parking assistance device 1 of this embodiment is installed in a vehicle 2 whose front wheels are steering wheels. As illustrated in FIG. 1, the parking assist device 1 includes an image conversion unit 10, a parking frame information detection unit 11, a step information detection unit 12, a control start SW detection unit 13, a control start determination unit 14, and a route. A change determination unit 15, a virtual parking frame setting unit 16, a forward travel route setting unit 17, a forward travel control unit 18, a reverse travel route setting unit 19, a reverse travel control unit 20, a torque calculation unit 21, Have

  The image conversion unit 10 includes a plurality of images captured by the front camera 20b (imaging unit), the left camera 20c (imaging unit), the rear camera 20d (imaging unit), and the right camera 20e (imaging unit) illustrated in FIG. To get. The front camera 20 b is attached to the front of the vehicle 2 and images the front nearest area including the front end of the vehicle 2. The left camera 20 c is attached to the left side of the vehicle 2, and images the left nearest region including the left end of the vehicle 2. The rear camera 20d is attached to the rear of the vehicle 2 and images the rear immediate vicinity region including the rear end of the vehicle 2. The right camera 20e is attached to the right side of the vehicle 2 and images the right nearest region including the right end of the vehicle 2. The image conversion unit 10 performs coordinate conversion on the plurality of images captured by the cameras 20b to 20e, and generates an overhead view of the vehicle 2 looking down from the sky. The image conversion unit 10 synthesizes the generated plurality of overhead views around the virtual image representing the vehicle 2 to generate one overhead image. This overhead view image is displayed on the display 20f (FIG. 2). Such a technique for generating a bird's-eye view image is already well known, for example, as proposed in Japanese Patent Application Laid-Open No. 5-79848 and Japanese Patent Application Laid-Open No. 2008-201270.

  The parking frame information detection unit 11 detects parking frame information related to the target parking frame W (FIG. 3) for parking the vehicle 2. For example, the parking frame information detection part 11 acquires the position where the vehicle is not parked as parking frame information among the parking frames drawn in the bird's-eye view image. A technique for detecting various kinds of information from an overhead image is already well known, for example, as proposed in Japanese Patent Application Laid-Open No. 5-79848, and the detailed description thereof will be omitted. By detecting the edge of the white line, that is, by extracting the strong contrast portion from the contrast of the adjacent pixels and detecting the position of the white line by line fitting, the position of the partition line Wi (FIG. 3) is acquired as the parking frame information.

  The step information detection unit 12 detects information about the step LD (FIG. 3). This level difference LD extends along a direction substantially orthogonal to the center line CL2 of the target parking frame W, and is a level difference formed on the approach path (path L shown in FIG. 8) to the target parking frame W. is there. The step information detection unit 12 (FIG. 1) includes the cameras 20b to 20e (FIG. 2) and a laser radar 70a (FIG. 2).

  The control start SW detection unit 13 detects an operation of the system operation SW 30 b (FIG. 2) by the driver of the vehicle 2.

  The control start determination unit 14 determines whether the detection signal detected by the control start SW detection unit 13 is correct. The control start determination unit 14 determines that the detection signal is correct when the detection signal is not noise or the like. When the detection signal is correct, the control start determination unit 14 outputs a positive signal indicating that to the path change determination unit 15.

  The route change determination unit 15 determines whether or not to change the route followed by the vehicle 2 when the vehicle 2 is guided to the target parking frame W.

  The virtual parking frame setting unit 16 sets a virtual parking frame VW (FIG. 4).

  The forward travel route setting unit 17 sets the forward travel route L1 (FIG. 4).

  The forward travel control unit 18 performs control for causing the vehicle 2 to travel forward along the forward travel route L1.

  The reverse travel route setting unit 19 sets the reverse travel route L2 (FIG. 6).

  The reverse travel control unit 20 performs control for causing the vehicle 2 to travel backward along the reverse travel route L2.

  The torque calculation unit 21 calculates the torque when the vehicle 2 rides on the step LD based on the height of the step LD.

  The step information detection unit 12, the route change determination unit 15, the virtual parking frame setting unit 16, the forward travel route setting unit 17, the forward travel control unit 18, the reverse travel route setting unit 19, the reverse travel control unit 20, and the torque calculation unit. Details of 21 will be described later.

  FIG. 2 is a hardware block diagram illustrating hardware elements that constitute the parking assistance apparatus 1.

  As shown in FIG. 2, the parking assistance device 1 sends a control command to each control module included in the parking assistance device 1 connected to a CAN (Controller Area Network) bus 3 laid in the vehicle 2. It has an ECU (Electronic Control Unit) 20a, an ADAS (Advanced Driving Assistant System) -ECU 30a, an engine ECU 40a, a brake ECU 50a, an electric power steering ECU 60a, and a laser radar 70a. Hereinafter, the electric power steering ECU 60a may be simply abbreviated as an electric power steering ECU 60a.

  A front camera 20b, a left camera 20c, a rear camera 20d, and a right camera 20e are connected to the camera ECU 20a. The camera ECU 20a controls the imaging operation of these cameras 20b to 20e.

  The camera ECU 20a is further connected to a display 20f for the driver of the vehicle 2 to check the operation status of the parking assist device 1. The display 20f is installed at a position where the driver can visually recognize, and displays an overhead view generated by the image conversion unit 10 (FIG. 1). The display 20f has a touch panel function, and the driver can input the pressed position coordinates by pressing a predetermined position on the display 20f. In addition, an operation menu of the parking assistance device 1 is displayed on the display 20f as appropriate, and the driver gives necessary instructions such as specifying a target parking position and inputting a parking method each time.

  The ADAS-ECU 30a is provided with a system operation SW 30b for instructing the start of parking assistance provided at a position where the driver of the vehicle 2 can easily operate, and when the parking assistance function is stopped due to an unexpected obstacle entry or the like. A control stop buzzer 30c for notifying the driver of the fact is connected to each other. The ADAS-ECU 30 a governs the overall operation of the parking assist device 1.

  An engine body (not shown) of the vehicle 2 is connected to the engine ECU 40a and controls the engine speed.

  A brake caliper 50b provided on each drive wheel of the vehicle 2 is connected to the brake ECU 50a, and the braking force of the vehicle 2 is controlled.

  A power steering motor 60b is connected to the electric power steering ECU 60a, and the steering control of the vehicle 2 is performed by controlling the direction and amount of rotation of the power steering motor 60b when performing a parking operation.

  The laser radar 70 a is attached to the front part of the vehicle 2. The laser radar 70a projects the oscillated pulsed laser light around the vehicle 2 and receives the reflected light of the laser light from the step LD (FIG. 3), so that the direction from the vehicle 2 to the step LD Measure distance.

(Description of automatic parking overview)
Hereinafter, the outline of the operation performed in the parking assistance device 1 will be described in order with reference to FIGS. 3 to 8, the images respectively captured by the cameras 20 b to 20 e (FIG. 2) installed in the vehicle 2 are coordinate-converted by the image conversion unit 10 (FIG. 1) as seen from above. This is an example in which a single overhead image is synthesized.

  As shown in FIGS. 3 to 8, for example, images that have been captured by the cameras 20 b to 20 e and coordinate-converted are synthesized around the current position of the vehicle 2 created by CG. Hereinafter, this image is referred to as a surrounding map I. This coordinate conversion and composition is started, for example, with the ON operation of the system operation SW 30b (FIG. 2), and thereafter continuously executed at a predetermined time interval. The synthesized surrounding map I is displayed as needed. 20f (FIG. 2).

  In Example 1, the path | route which guides the vehicle 2 to the target parking frame W designated based on the bird's-eye view image shown in FIGS. 3-8 is set. In the first embodiment, as shown in FIGS. 3 to 8, for example, a step LD exists at the boundary between the road surface and the target parking frame W. Therefore, the parking assist device 1 causes the vehicle 2 to travel forward to the left in order to park backward from the parking start position P1 (FIG. 4) to the target parking frame W (FIG. 3) existing on the right side of the vehicle 2, By switching the steering direction and the traveling direction of the vehicle 2, a route L (FIG. 8) for traveling backward in the target parking frame W is set.

(Description of lane markings indicating the target parking frame)
First, the lane marking indicating the target parking frame will be described with reference to FIG.

  As shown in FIG. 3, the target parking frame W is configured by a dividing line drawn on the road surface with, for example, a white line or a yellow line. FIG. 3 is an example of a lane marking Wi drawn so as to define the left and right sides of the target parking frame W. The vehicle 2 is parked with respect to the target parking frame W on which the lane markings Wi are drawn.

(Description of how to specify the target parking position)
Next, a method for specifying the target parking position S1 when the parking assist device 1 is operated will be described with reference to FIG.

  The driver of the vehicle 2 stops the vehicle 2 and designates the target parking frame W while confirming the surrounding map I displayed on the display 20f (FIG. 2). Specifically, the driver of the vehicle 2 follows the arrow shown in white in FIG. 3 until the target parking frame W that he / she wants to park appears in the surrounding map I displayed on the display 20f. Then, the vehicle 2 is temporarily stopped. Thereafter, the target parking position (one point inside the target parking frame W) in the display 20f is touched with a finger, and the coordinates of the target parking position S1 (FIG. 7) are input.

  Information indicating the coordinates of the input target parking position S1 is transmitted to the parking frame information detection unit 11 (FIG. 1). The parking frame information detection unit 11 detects a lane marking Wi that defines the target parking frame W including the target parking position S1.

  The lane marking Wi is detected, for example, by capturing an image including the coordinates of the target parking position S1 among the four cameras (front camera 20b, left camera 20c, rear camera 20d, and right camera 20e) constituting the imaging unit. This is performed on an image picked up by the camera to be selected.

  The detection of white lines and yellow lines drawn on the road surface by image processing may be performed using any known method.

  For example, a lane marking Wi composed of a white line or a yellow line drawn on the road surface is generally imaged brighter than the road surface. Therefore, a point (pixel) having a positive luminance difference with respect to the road surface is detected, and a region surrounded by the detected point and having a predetermined width is defined as a region representing the partition line Wi. What is necessary is just to detect. In addition, according to this method, dirt or dirt on the road surface may be detected. Therefore, after detecting a corresponding point, a constraint condition such that a plurality of detected points form a straight line is set. It is preferable to apply and select a region representing the lane marking Wi.

(Explanation of information detection method for steps)
Next, a method for detecting information related to the level difference LD will be described with reference to FIG. The level difference information detection unit 12 (FIG. 1) detects information indicating the height of the level difference LD as information regarding the level difference LD based on images obtained by imaging with the cameras 20b to 20e (FIG. 2). The step information detection unit 12 (FIG. 1) detects information indicating the direction and distance from the vehicle 2 to the step LD as information on the step LD based on the detection result of the laser radar 70a (FIG. 2).

  Such an information detection technique is already well known, for example, as proposed in Japanese Patent Application Laid-Open No. 2005-234999, and detailed description thereof is omitted. In the first embodiment, the laser radar 70a (FIG. 2) is omitted. The information indicating the direction and distance from the vehicle 2 to the step LD is detected using the property that the intensity of the light reflected by the edge portion of the step LD becomes particularly strong when the laser beam is irradiated.

  Further, the step information detection unit 12 adds the direction and distance from the vehicle 2 to the step LD obtained by the detection of the laser radar 70a (FIG. 2), and the cameras 20b to 20e to the overhead image generated by the image conversion unit 10. Information indicating the height of the step LD obtained by the imaging in FIG. 2 is associated.

(Description of parking method selection)
After the setting of the target parking position S1 is completed, the driver designates a parking method. Specifically, a parking method to be performed is selected from a menu for selecting a parking method displayed on the display 20f. In the first embodiment, it is assumed that parallel parking is selected by reverse running.

(Explanation of route change judgment method)
Next, a method for determining a route change when a parking method is selected will be described with reference to FIG.

  When the parking method is selected, the route followed by the vehicle 2 when the vehicle 2 is guided to the target parking frame W is changed from the route L ′ to the route L by the action of the route change determination unit 15 (FIG. 1). A determination is made whether or not. This determination is made according to the presence or absence of the step LD.

  The route L ′ is a route that is set as a normal garage route and is followed by the vehicle 2 when there is no step LD. The route L ′ turns the vehicle 2 while steering the vehicle 2 in the right direction opposite to the forward traveling after the vehicle 2 moves forward while turning leftward with respect to the target parking frame W so as to pass the target parking frame W. In this state, the vehicle travels backward and leads to the target parking frame W. The route L ′ includes a forward travel route L1 ′ and a reverse travel route L2 ′. The route L is a route followed by the vehicle 2 when the step LD exists. The route L includes a forward travel route L1 and a reverse travel route L2. Details of the method for setting the forward travel route L1 and the reverse travel route L2 will be described later.

  In the first embodiment, as described above, the step LD exists at the boundary between the road surface and the target parking frame W. Accordingly, the route change determination unit 15 (FIG. 1) changes the route followed by the vehicle 2 from the route L ′ before the change to the route L after the change, as shown in FIG.

  Note that as information necessary for determining the route change, coordinates on the surrounding map I and information detected by the step information detection unit 12 are used as necessary.

(Description of virtual parking frame setting method)
Next, the setting method of the virtual parking frame VW (FIG. 4) is demonstrated using FIG.3 and FIG.4.

  As shown in FIG. 4, the virtual parking frame setting unit 16 (FIG. 1) is a virtual parking frame that guides the vehicle 2 by forward travel to a position facing the target parking frame W across the extension line of the center line CL <b> 1 of the vehicle 2. Set VW. As shown in FIG. 4, the virtual parking frame VW has a center line CL3 that coincides with an extension line of the center line CL2 of the target parking frame W.

  As shown in FIG. 3, the center line CL1 is a line segment having both the position B of the front camera 20b and the position C of the rear camera 20d as both ends. As shown in FIG. 3, the center line CL2 passes through a point D that bisects a line segment K having both ends K1 and K2 of the two left and right dividing lines Wi on the vehicle 2 approach side, and , A line segment perpendicular to the line segment K.

(Description of forward travel route setting method)
Next, a method for setting the forward travel route L1 (FIG. 4) will be described with reference to FIGS.

  The forward travel route setting unit 17 (FIG. 1) sets an arcuate forward travel route L1 as shown in FIG. As shown in FIG. 5, the forward travel route L1 maintains the turning angle δ of the vehicle 2 at the parking start position P1 (FIG. 4) at the maximum turning angle δmax at least up to the virtual parking frame VW. This is a route that turns the vehicle 2 forward and leads to the virtual parking frame VW until the center line CL1 of the vehicle 2 coincides with the center line CL3 of the virtual parking frame VW.

Specifically, the forward travel route setting unit 17 calculates the maximum turning angle δmax using the following equation (1) based on a two-wheel model in which a four-wheel vehicle is replaced with a two-wheel vehicle as shown in FIG. .

  Here, L is a wheel base of the vehicle 2. As shown in FIG. 4, the wheel base L includes a center position E of the front axle that connects the right front wheel 20FR and the left front wheel 20FL, and a center position F of the rear axle that connects the right rear wheel 20RR and the left rear wheel 20RL. Is a line segment with both ends. In the two-wheel model shown in FIG. 11, the front wheel FC is set at the center position E of the front axle, and the rear wheel RC is set at the center position F of the rear axle. As shown in FIG. 11, the turning radius R is the radius of the circle when the two-wheel model rotates at the maximum turning angle δmax, and this is the center line CL1 of the vehicle 2 and the center of the virtual parking frame VW in FIG. The line CL3 is applied to the radius of a circle having two tangent lines.

  Information necessary for setting the forward travel route L1 is read from the coordinates on the surrounding map I as necessary and used.

(Explanation of control method for vehicle forward travel)
Next, a method for controlling the forward travel of the vehicle 2 will be described with reference to FIGS. 4 and 5.

  The forward travel controller 18 (FIG. 1) causes the vehicle 2 to travel forward along the forward travel route L1 as shown in FIG. That is, the forward travel control unit 18 steers the vehicle 2 based on the maximum turning angle δmax as shown in FIG. Specifically, the forward travel control unit 18 controls the power steering motor 60b (FIG. 2), and the right front wheel 20FR and the left front wheel 20FL are steered leftward as shown in FIG.

  While the forward travel control unit 18 is performing forward travel control, the camera ECU 20a (FIG. 1) detects whether the center line CL1 of the vehicle 2 coincides with the center line CL3 of the virtual parking frame VW at any time. Is performed using the camera image.

  When the coincidence is detected, the forward travel control unit 18 operates the brake caliper 50b (FIG. 2), and as shown in FIG. 5, the center line CL3 of the virtual parking frame VW is aligned with the center line of the vehicle 2. The vehicle 2 is stopped at a position P2 where the two coincide. In the state after the stop, the forward travel control unit 18 controls the power steering motor 60b (FIG. 2), and the right front wheel 20FR and the left front wheel 20FL are steered in a straight traveling state as shown in FIG. It is returned to a direction parallel to the center line CL1.

  Information necessary for controlling the forward travel is read out from the coordinates on the surrounding map I as necessary and used.

(Description of reverse travel route setting method)
Next, a method for setting the reverse travel route L2 (FIG. 6) will be described with reference to FIGS.

  The reverse travel route setting unit 19 (FIG. 1) sets a straight reverse travel route L2 as shown in FIG. The reverse travel route L2 is a route that guides the vehicle 2 straight from the virtual parking frame VW along the center line CL2 of the target parking frame W to the target parking frame W.

  Information necessary for setting the reverse travel route L2 is read from the coordinates on the surrounding map I as necessary and used.

(Explanation of control method for vehicle reverse running)
Next, a method for controlling the backward travel of the vehicle 2 will be described with reference to FIGS. 6 and 7.

  The reverse travel control unit 20 (FIG. 1) causes the vehicle 2 to travel backward as shown in FIG. Specifically, the reverse travel control unit 20 (FIG. 1) controls the engine ECU 40a (FIG. 2) to cause the vehicle 2 to travel backward along the reverse travel route L2, as shown in FIG.

  While the reverse travel control unit 20 is performing the reverse travel control, the camera ECU 20a (FIG. 1) detects whether or not the center position E has reached the step LD using the camera image. In the torque calculation unit 21 (FIG. 1), the torque when the vehicle 2 rides on the step LD is calculated.

  Specifically, the torque calculation unit 21 calculates the amount of increase in torque obtained by multiplying the height of the level difference LD detected by the level difference information detection unit 12 by a coefficient.

  The reverse travel control unit 20 controls the engine ECU 40a (FIG. 2) so as to adjust the reverse speed of the vehicle 2 so as to correspond to the amount of torque increase calculated by the torque calculation unit 21 when the vehicle 2 rides on the step LD. increase. The reverse travel control unit 20 causes the vehicle 2 to travel backward at the increased reverse speed to get over the step LD.

  While the vehicle 2 is riding on the step LD, the camera ECU 20a (FIG. 1) detects whether the vehicle 2 has passed the step LD using the camera image.

  When it is detected that the vehicle 2 has passed the level difference LD, the reverse travel control unit 20 controls the engine ECU 40a (FIG. 2) to increase corresponding to the amount of torque increase calculated by the torque calculation unit 21. The vehicle 2 is made to travel backward at a reference speed slower than the reverse speed.

  While the reverse travel control unit 20 is performing the reverse travel control, the camera ECU 20a (FIG. 1) detects whether or not the vehicle 2 has reached the target parking position S1 using the camera image. .

  When the arrival is detected, the reverse travel control unit 20 then operates the brake caliper 50b (FIG. 2) to stop the vehicle 2 at the target parking position S1, as shown in FIG. That is, as shown in FIG. 7, the reverse travel control unit 20 performs the vehicle at the target parking position S1 based on the positional relationship between the step LD and the center position E of the front axle that connects the right front wheel 20FR and the left front wheel 20FL. Stop 2

  Specifically, as shown in FIG. 7, the camera ECU 20a (FIG. 2) determines that the center position E of the front axle that connects the right front wheel 20FR and the left front wheel 20FL straddles the step LD and further reaches the target parking frame by a predetermined distance. When the vehicle 2 enters W, the vehicle 2 reaches the target parking position S1, and it is determined that the parallel parking to the target parking frame W is completed, and the reverse travel control unit 20 operates the brake caliper 50b (FIG. 2). Then, the vehicle 2 is stopped.

  Note that information necessary for control of reverse travel is read out from the coordinates on the surrounding map I as necessary and used.

(Description of the flow of processing in the embodiment)
The outline of the process performed in the parking assistance apparatus 1 has been described above. Next, the overall process flow will be described with reference to the flowcharts of FIGS. 9 and 10.

  (Step S10) In the parking frame information detection part 11 (FIG. 1), the detection of the parking frame information regarding the target parking frame W (FIG. 3) which parks the vehicle 2 is performed.

  (Step S11) In the camera ECU 20a (FIG. 2), it is detected whether or not the detection of the parking frame information is completed. If the completion is detected (YES in step S11), the process proceeds to step S12. If the completion is not detected (NO in step S11), step S10 is repeated.

  (Step S12) The control start determination unit 14 (FIG. 1) determines whether the detection signal is correct. If the detection signal is correct (YES in step S12), the control start determination unit 14 proceeds to step S13, and if the detection signal is not correct due to noise or the like (NO in step S12), repeats step S12.

  (Step S13) In the route change determination unit 15 (FIG. 1), it is determined whether or not the route followed by the vehicle 2 is changed from the route L ′ to the route L according to the presence or absence of the step LD. When the route followed by the vehicle 2 is changed to the route L (YES in step S13), the process proceeds to step S14, and the route followed by the vehicle 2 is not changed to the route L but is maintained on the route L ′ (in step S13). NO), the process proceeds to step S27 in FIG.

  (Step S14) The virtual parking frame setting unit 16 (FIG. 1) sets the virtual parking frame VW (FIG. 4).

  (Step S15) The forward travel route L1 (FIG. 4) and the reverse travel route L2 (FIG. 6) are set in the forward travel route setting unit 17 (FIG. 1) and the reverse travel route setting unit 19 (FIG. 1), respectively. .

  (Step S16) The forward travel control unit 18 (FIG. 1) performs forward travel control of the vehicle 2 along the forward travel route L1 (FIG. 4).

  (Step S17) In the camera ECU 20a (FIG. 2), it is detected whether or not the center line CL1 of the vehicle 2 matches the center line CL3 of the virtual parking frame VW. When the coincidence is detected (YES in step S17), the process proceeds to step S18. When the coincidence is not detected (NO in step S17), step S16 is repeated.

  (Step S18) Stop control of the vehicle 2 is performed in the forward travel control unit 18 (FIG. 1).

  (Step S19) In the torque calculator 21 (FIG. 1), the amount of increase in torque based on the height of the step LD is calculated.

  (Step S20) The reverse travel control unit 20 (FIG. 1) increases the reverse speed of the vehicle 2 so as to correspond to the amount of increase in torque.

  (Step S21) In the camera ECU 20a (FIG. 2), the distance between the step LD and the center position E is calculated.

  (Step S22) In the camera ECU 20a (FIG. 2), it is detected whether or not the center position E has reached the position of the step LD. If the arrival is detected (YES in step S22), the process proceeds to step S23. If the arrival is not detected (NO in step S22), step S20 is repeated.

  (Step S23) In the reverse travel control unit 20 (FIG. 1), deceleration control to a reference speed slower than the reverse speed increased corresponding to the amount of increase in torque is performed.

  (Step S24) In the reverse travel control unit 20 (FIG. 1), the reverse travel control of the vehicle 2 along the reverse travel route L2 (FIG. 6) is performed.

  (Step S25) In the camera ECU 20a (FIG. 2), it is detected whether or not the vehicle 2 has reached the target parking position S1. When the arrival is detected (YES in step S25), the process proceeds to step S26, and when the arrival is not detected (NO in step S25), step S24 is repeated.

  (Step S26) Stop control of the vehicle 2 is performed in the reverse travel control unit 20 (FIG. 1).

  (Step S27) On the other hand, when the route is maintained at route L ′ in Step S13 (NO in Step S13), the speed of the vehicle 2 is set to a predetermined reference speed in the engine ECU 40a (FIG. 2).

  (Step S28) The forward travel control unit 18 (FIG. 1) performs forward travel control of the vehicle 2 along the forward travel route L1 ′ (FIG. 8).

  (Step S29) In the reverse travel control unit 20 (FIG. 1), the reverse travel control of the vehicle 2 along the reverse travel route L2 ′ (FIG. 8) is performed.

  (Step S30) In the camera ECU 20a (FIG. 2), it is detected whether or not the vehicle 2 has reached the target parking position S1. When the arrival is detected (YES in step S30), the process proceeds to step S26, and when the arrival is not detected (NO in step S30), step S28 is repeated.

  As described above, according to the parking assist device 1 of the first embodiment configured as described above, when the information regarding the step LD is detected by the step information detection unit 12, the virtual parking frame setting unit 16 sets the target Virtual parking that has a center line CL3 that coincides with an extension line of the center line CL1 of the parking frame W, and guides the vehicle 2 forwardly to a position facing the target parking frame W across the extension line of the center line CL1 of the vehicle 2 A frame VW is set.

  According to the parking assistance device 1 of the first embodiment, the vehicle 2 can be guided forward to the virtual parking frame VW when information regarding the step LD is detected. As a result, before the vehicle 2 moves backward toward the target parking frame W, a route for guiding the vehicle 2 to the virtual parking frame VW that can travel straight forward and backward with respect to the target parking frame W can be set.

  That is, according to the parking assistance device 1 of the first embodiment, once the vehicle 2 is guided to the virtual parking frame VW, thereafter, the vehicle 2 is caused to enter the target parking frame W by traveling backward in a straight traveling state. be able to.

  For this reason, the right rear wheel 20RR and the left rear wheel 20RL of the vehicle 2 can enter the target parking frame W at the same time. As a result, the right rear wheel 20RR and the left rear wheel 20RL of the vehicle 2 ride on the step LD simultaneously. That is, the right rear wheel 20RR and the left rear wheel 20RL can be prevented from slipping because the right rear wheel 20RR and the left rear wheel 20RL can be prevented from being displaced at the timing when they ride on the step LD. Therefore, it is difficult for a lateral shift to occur with respect to the locus (route L2) drawn by the vehicle 2 traveling backward.

  Moreover, according to the parking assistance apparatus 1 of Example 1, the level | step difference information detection part 12 adds the direction and distance from the vehicle 2 to the level | step difference LD, and the height of the level | step difference LD to the bird's-eye view image produced | generated by the image conversion part 10. Correlate the information shown. That is, the bird's-eye view image is displayed on the display 20f in a form in which the step LD is compared with an object other than the step LD. For this reason, for example, the positional relationship between the level difference LD and the vehicle 2 and the difference in height between the level difference LD and the vehicle 2 become obvious to the driver. Therefore, the driver can clearly grasp the position of the step LD in the overhead view image.

  Moreover, according to the parking assistance apparatus 1 of Example 1, the vehicle 2 can be guide | induced to a virtual parking frame VW by forward travel using the forward parking function already equipped in the vehicle 2 as it is. For this reason, it is not necessary to introduce extra software when the vehicle 2 is guided to the virtual parking frame VW. Therefore, the manufacturing cost of the parking assistance apparatus 1 can be reduced compared with the case where extra software is introduced.

  In the first embodiment, an example in which the parking assist device of the present invention is applied to a vehicle is shown. However, the parking assist apparatus of the present invention can be similarly applied to a moving body (for example, an electric wheelchair or the like) including a steering wheel, a steering mechanism, and a drive system thereof.

  Further, in the first embodiment, the target parking frame W is shown as an example of a parking frame having a lane marking Wi drawn so as to define the left and right. However, it is not limited to this. For example, a parking frame having a lane line drawn so as to surround the four sides, a parking frame having a lane line drawn to define the left and right sides, the front or the rear, the front and rear of the parking position, the left side or the right side A parking frame having a lane marking drawn so as to define the direction may be set as the target parking frame W. Further, for example, a parking frame on which no lane marking is drawn may be set as the target parking frame W.

  Furthermore, in the first embodiment, an example is shown in which the center line CL1 of the vehicle 2 is configured by line segments having both ends of the position B of the front camera 20b and the position C of the rear camera 20d. However, it is not limited to this. For example, as shown in FIG. 4, the center position E of the front axle connecting the right front wheel 20FR and the left front wheel 20FL and the center position F of the rear axle connecting the right rear wheel 20RR and the left rear wheel 20RL are both ends. The center line CL1 of the vehicle 2 may be configured by a line segment.

  Furthermore, in Example 1, the parking frame information detection part 11 showed the example which detects parking frame information from the bird's-eye view image which converted the image imaged by the imaging part. However, it is not limited to this. For example, parking frame information may be detected using a sensor that can perform three-dimensional measurement such as a laser sensor, or parking frame information may be detected using GPS (Global Positioning System) data.

  Further, in the first embodiment, an example in which the step LD is present at the boundary between the road surface and the target parking frame W is shown. However, it is not limited to this. For example, there may be a step in the parking frame where the wheel must get over, such as a coin parking with a step. In such a case, the camera ECU 20a (FIG. 2) determines that the center position F of the rear axle that connects the right rear wheel 20RR and the left rear wheel 20RL straddles a step, or straddles the step, and further a predetermined distance. When the vehicle enters the parking frame, it may be determined that the vehicle 2 has reached the target parking position S1 and parallel parking to the target parking frame W has been completed.

  In the first embodiment, an example is shown in which the reverse speed is always increased during reverse travel from the virtual parking frame VW to the target parking frame W (steps S20 to S22 shown in FIG. 10). However, it is not limited to this. For example, the reverse speed may be increased only when the wheel rides on the step LD.

  As mentioned above, although the Example of this invention was explained in full detail with drawing, since an Example is only an illustration of this invention, this invention is not limited only to the structure of an Example. Of course, changes in design and the like within a range not departing from the gist are included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... Parking assistance apparatus 2 ... Vehicle 10 ... Image conversion part 11 ... Parking frame information detection part 12 ... Step information detection part 16 ... Virtual parking frame setting part 17 ... Advance Traveling route setting unit 18 ... Forward traveling control unit 19 ... Reverse traveling route setting unit 20 ... Reverse traveling control unit 20b ... Front camera (imaging unit)
20c ... Left camera (imaging unit)
20d: Rear camera (imaging unit)
20e ... Right camera (imaging part)
21 ... Torque calculation unit 70a ... Laser radar CL1, CL2, CL3 ... Center line L ... Path L1 ... Forward travel path L2 ... Reverse travel path LD ... Step P1 ...・ Parking start position VW ... virtual parking frame W ... target parking frame δ ... steering angle δmax ... maximum steering angle

Claims (4)

A parking assist device for setting a route for causing a vehicle to travel forward in order to park in a target parking frame located on the side of the vehicle, switching a traveling direction of the vehicle, and traveling backward in the target parking frame. ,
A step information detecting unit that extends along a direction substantially orthogonal to the center line of the target parking frame and detects information about a step formed on the approach path to the target parking frame;
When information about the step is detected by the step information detection unit, the target parking has a center line that coincides with an extension line of the center line of the target parking frame and sandwiches the extension line of the center line of the vehicle A virtual parking frame setting unit that sets a virtual parking frame that guides the vehicle in forward travel to a position facing the frame;
In a state where the turning angle of the vehicle is maintained at the maximum turning angle at least up to the virtual parking frame, the vehicle is turned in forward travel until the center line of the vehicle coincides with the center line of the virtual parking frame, A forward travel route setting unit for setting an arcuate forward travel route leading to a virtual parking frame;
Forward travel control for causing the vehicle to travel forward along the forward travel route set by the forward travel route setting unit, and stopping the vehicle at a position where the center line of the vehicle coincides with the center line of the virtual parking frame. And
A reverse travel route setting unit that sets a linear reverse travel route that guides the vehicle straight from the virtual parking frame along the center line of the target parking frame to the target parking frame.
A parking assist device, comprising: a reverse travel control unit that causes the vehicle to travel backward along the reverse travel route set by the reverse travel route setting unit, and stops the vehicle on the target parking frame. . The step information detection unit detects information indicating the height of the step as information on the step,
Torque calculated by the reverse travel control unit based on the height of the step when the vehicle travels backward along the reverse travel route set by the reverse travel route setting unit. Have a calculator,
The parking assist device according to claim 1, wherein the reverse travel control unit causes the vehicle to travel backward with the torque calculated by the torque calculation unit when the vehicle climbs the step. The reverse running control unit
The parking assist device according to claim 2, wherein when the vehicle passes over the step, the vehicle is caused to travel backward with a torque smaller than the torque calculated by the torque calculation unit. The step information detection unit includes an imaging unit that images the surroundings of the vehicle and a laser radar, and based on an image obtained by imaging by the imaging unit and a detection result of the laser radar, Detecting information indicating the direction and distance from the vehicle to the step and the height of the step as information on the step,
An image conversion unit that converts an image obtained by imaging by the imaging unit into an overhead image,
The level difference detection unit associates information indicating a direction and distance from the vehicle to the level difference and the height of the level difference with the overhead view image, according to any one of claims 1 to 3. The parking assistance device described.