JP5400316B2 - Parking assistance device - Google Patents

Description

The present invention relates to a parking support apparatus that is mounted on a vehicle and supports parking of the vehicle.

Conventionally, various parking assistance devices that assist vehicle parking have been proposed (see, for example, Patent Document 1). In the parking assistance device described in Patent Document 1, a predicted travel locus when the host vehicle turns while maintaining the current steering angle is calculated, and the predicted travel locus that is variable according to the steering angle is calculated by a camera. By superimposing the captured image on the back of the vehicle and displaying it on the monitor, the driver recognizes the optimum steering angle for properly parking the vehicle in the target parking space, and supports parking. ing.
Japanese Patent No. 3767600

  However, in the parking assistance device described in Patent Document 1, since only the predicted travel locus is superimposed on the image behind the host vehicle and displayed on the monitor, the rear part of the host vehicle is placed in the target parking space. However, after that, the driver cannot recognize whether the vehicle can be parked so as not to be inclined in the parking space, and improvement is required. It was.

The present invention was devised to solve the above-described problems of the prior art, and when the steering is switched back at any point, the vehicle is parked so as not to be inclined in the parking space. An object of the present invention is to provide a parking assistance device that can make a driver accurately recognize whether or not the vehicle can be parked and assist the parking so that the vehicle can be parked in the correct posture.

The parking assist device according to the present invention captures an image around the own vehicle, detects a parking space and a parking direction in the parking space from the image around the own vehicle, and maintains the current steering angle. A predicted travel locus when the vehicle turns is calculated, and a point on the predicted travel locus and where the direction of the vehicle is the same as the parking direction in the parking space is calculated. That is, a tangent line that is in contact with the predicted traveling locus and parallel to the parking direction detected by the parking direction detecting means is obtained, and a contact point between the tangent line and the predicted traveling locus is calculated as the point. Then, the first virtual vehicle icon corresponding to the size of the vehicle is superimposed on the position corresponding to the current position of the vehicle on the image around the vehicle, and the calculation on the image around the vehicle is performed. A second virtual vehicle icon corresponding to the size of the vehicle is superimposed at the position corresponding to the spot in the same direction as the parking direction in the parking space, and the predicted traveling locus is represented on the image around the vehicle. A trajectory icon is superimposed, and an image around the own vehicle in which the first virtual vehicle icon, the second virtual vehicle icon, and the trajectory icon are superimposed is displayed on the monitor.
The parking assist device converts an image captured by the camera into an overhead view image looking down from a virtual viewpoint above the own vehicle, and converts the first virtual vehicle icon and the second virtual image into the surrounding image converted into the overhead image. The virtual vehicle icon and the trajectory icon are superimposed. The parking assistance device superimposes a frame figure corresponding to the outer peripheral shape of the host vehicle on the image around the host vehicle as the second virtual host vehicle icon, and the host vehicle displays the current steering angle as the track icon representing the predicted travel track. An arc-shaped line passing through a portion that is the outermost periphery of the turn when turning while superimposing is superimposed on the image around the vehicle.
The parking assistance device analyzes an image around the vehicle to recognize the longitudinal direction of the parking space, detects the longitudinal direction of the parking space as the parking direction, and the current position of the own vehicle reaches the calculated point. When this is done, the superimposition of the second virtual vehicle icon ends. When the distance from the current position of the host vehicle to the calculated point is equal to or greater than a predetermined value, the parking assist device uses the track icon representing a predicted travel path when the host vehicle turns while maintaining the current steering angle. The arc-shaped line that passes through the part that is the outermost periphery of the turn and the arc-shaped line that passes through the part that is the innermost periphery of the turn are superimposed on the image around the own vehicle, from the current position of the own vehicle to the calculated point If the distance of the vehicle is less than the predetermined value, an arc-shaped line that passes through the part that becomes the outermost turning corner when the vehicle turns while maintaining the current steering angle is used as a track icon that represents the predicted driving track. Is superimposed on the image.

  According to the present invention, on the image around the host vehicle, the first virtual host vehicle icon is present at the current position of the host vehicle, and when the host vehicle turns along the predicted travel locus, the direction of the host vehicle is in the parking space. Since the second virtual vehicle icon is superimposed and displayed at a position that coincides with the parking direction, the driver of the vehicle can see the first virtual vehicle icon while looking at the image displayed on the monitor. When the vehicle overlaps with the second virtual vehicle icon, the steering is switched back, so that the vehicle can be parked in the correct posture in the parking space. As described above, according to the present invention, the driver can accurately recognize at which point the vehicle can be parked so as not to be inclined in the parking space by switching back the steering. Parking can be assisted so that the vehicle can be parked in the correct posture.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Device configuration]
FIG. 1 is a block diagram showing a configuration of a parking assistance apparatus to which the present invention is applied. This parking assistance device is provided with respect to the control unit 10 such as a front camera 1a, a rear camera 1b, a right side camera 1c, and a left side camera 1d, a steering angle sensor 2, an inhibitor switch 3, and a parking assistance. The start switch 4 and the monitor 5 are connected to each other.

  The four in-vehicle cameras 1a to 1d are respectively installed at four locations on the front, rear, left and right sides of the vehicle, and image a road surface within a predetermined distance range around the host vehicle, for example, a range of about 5 m from the host vehicle. Output to.

  The steering angle sensor 2 is attached to the steering shaft of the vehicle, detects the steering direction and the steering angle of the steering wheel, and outputs a detection signal to the control unit 10.

  The inhibitor switch 3 detects the shift position in conjunction with the operation of the shift lever of the vehicle, and outputs a detection signal to the control unit 10.

  The parking assist activation switch 4 is installed on an instrument panel or a steering handle in the passenger compartment, and is activated by a driver of the vehicle to instruct the control unit 10 to start a parking assist operation. Is output.

  The monitor 5 is installed on an instrument panel in the passenger compartment, and displays an image for parking assistance by the output of the control unit 10. As the monitor 5, any known display device such as a liquid crystal panel or CRT can be used. For example, a display device used for displaying navigation information in an in-vehicle navigation device can be used. is there.

  The control unit 10 is composed of, for example, a CPU provided with an internal memory, and comprehensively controls the overall operation of the parking assistance device by executing a parking assistance program stored in advance. The control unit 10 includes a viewpoint conversion unit 11, an overhead image creation unit 12, a parking space detection unit 13, a parking direction detection unit 14, a predicted travel locus calculation unit 15, and a point calculation unit 16 as functional parts related to the parking assistance operation. , A memory 17, an icon acquisition unit 18, and an image composition unit 19.

  The viewpoint conversion unit 11 arranges pixels for each of the image frames based on the image signals from the four on-vehicle cameras 1a to 1d so that each image frame is an image frame from a viewpoint with the camera optical axis perpendicular to the road surface. A process of converting to a changed image signal is performed. The image signals of the in-vehicle cameras 1a to 1d whose viewpoints are converted by the viewpoint conversion unit 11 are sent to the overhead image creation unit 12.

  The bird's-eye view image creation unit 12 joins the image signals that have undergone viewpoint conversion of the in-vehicle cameras 1a to 1d, and creates a bird's-eye view image that shows a state of looking down from the virtual viewpoint directly above the own vehicle, in front, rear, left, and right. create. The bird's-eye view image created by the bird's-eye view image creation unit 12 is sent to the parking space detection unit 13, the predicted travel locus calculation unit 15, and the image composition unit 19, respectively.

  The parking space detection unit 13 performs image processing such as edge detection on the bird's-eye view image generated by the bird's-eye image creation unit 12 to detect a parking space that is a parking target of the vehicle. Here, the parking unit is automatically detected by the control unit 10 by image processing on the bird's-eye view around the host vehicle, but other than that, for example, the bird's-eye view around the own vehicle is displayed on the monitor 5. Thus, it is possible to recognize the position designated by the driver of the own vehicle on the overhead image displayed on the monitor 5 and set the position as a parking space.

  The parking direction detection unit 14 detects the parking direction in the parking space detected by the parking space detection unit 13 from the overhead image around the host vehicle. This parking direction is the direction of the vehicle when the vehicle is parked in the correct posture in the parking space. In the bird's-eye view image created by the bird's-eye view image creation unit 12, the front-rear direction (Y-axis direction) of the own vehicle is fixed. The direction is the parking direction in the parking space. The parking direction detection unit 14 performs image processing on the overhead image around the host vehicle, detects the longitudinal direction of the parking space detected from the overhead image around the host vehicle by the parking space detection unit 13, and detects the longitudinal direction of the parking space. And the Y-axis direction of the host vehicle are detected as the parking direction in the parking space. The angle information indicating the parking direction detected by the parking direction detection unit 14 is sent to the point calculation unit 16 and the icon acquisition unit 18.

  The predicted travel locus calculation unit 15 reads the detection signal of the steering angle of the own vehicle detected by the steering angle sensor 2 and the detection signal of the shift position of the own vehicle detected by the inhibitor switch 3, and the own vehicle is currently What is the vehicle on the bird's-eye view around the vehicle created by the bird's-eye view image creation unit 12 when turning in the traveling direction (forward or backward) corresponding to the shift position while maintaining the steering angle? A predicted traveling locus indicating whether the vehicle is traveling along the locus is calculated. Since this predicted travel locus changes according to the change in the steering angle of the host vehicle, the predicted travel locus calculation unit 15 newly calculates the predicted travel locus every time the detection signal of the rudder angle sensor 2 changes. Is calculated. Information on the predicted travel locus calculated by the predicted travel locus calculation unit 15 is sent to the point calculation unit 16, the icon acquisition unit 18, and the image composition unit 19, respectively.

  The point calculation unit 16 is a point on the predicted travel locus calculated by the predicted travel locus calculation unit 15 and the same direction as the parking direction detected by the parking direction detection unit 14 (hereinafter, direction). It is called a coincidence point). The predicted travel trajectory calculated by the predicted travel trajectory calculation unit 15 is an arc-shaped trajectory having a curvature corresponding to the current steering angle of the host vehicle. The point calculating unit 16 obtains a tangent line that is in contact with the arc-shaped locus and is parallel to the parking direction detected by the parking direction detecting unit 14, and calculates the contact point as a direction matching point. Information on the direction coincidence point calculated by the point calculation unit 16 is sent to the image composition unit 19.

  The memory 17 stores various icons to be superimposed on the bird's-eye view around the vehicle, and includes a first virtual vehicle icon storage unit 17a that stores the first virtual vehicle icon, and a second virtual vehicle. It has the 2nd virtual own vehicle icon memory | storage part 17b which memorize | stores a car icon, and the locus | trajectory icon memory | storage part 17c which memorize | stores a locus | trajectory icon. The first virtual vehicle icon is an icon representing the current position of the vehicle on the bird's-eye view image around the vehicle, and a computer graphics image simulating the vehicle is used. Further, the second virtual vehicle icon is an icon for allowing the driver of the vehicle to easily recognize the steering switchback position when parking in the parking space detected by the parking space detection unit 13, for example, The frame figure corresponding to the outer periphery shape of the own vehicle is used. The trajectory icon is an icon representing the predicted travel trajectory calculated by the predicted travel trajectory calculation unit 15, and an arc-shaped line is used.

  Based on the angle information from the parking direction detection unit 14, the icon acquisition unit 18 has a direction that matches the parking direction detected by the parking direction detection unit 14 from the second virtual vehicle icon storage unit 17 b of the memory 17. The second virtual vehicle icon is acquired, and the prediction calculated by the predicted traveling locus calculation unit 15 from the locus icon storage unit 17c of the memory 17 based on the predicted traveling locus information from the predicted traveling locus calculation unit 15 is obtained. A trajectory icon having a curvature that matches the travel trajectory is acquired, and the second virtual vehicle icon and trajectory icon acquired from the memory 17 are sent to the image composition unit 19.

  The image composition unit 19 creates a display image to be displayed on the monitor 5 by superimposing various icons on the bird's-eye view image around the host vehicle created by the bird's-eye view image creation unit 12. Specifically, the image composition unit 19 acquires the first virtual vehicle icon from the first virtual vehicle icon storage unit 17a of the memory 17, and the current position of the vehicle on the overhead image around the vehicle. Is superimposed on the first virtual vehicle icon at a size corresponding to the size of the vehicle. The bird's-eye view image created by the bird's-eye view image creation unit 12 is created with the current position of the vehicle as a reference, for example, so that the current position of the vehicle is at the center of the image. The first virtual vehicle icon is superimposed on a position that serves as a reference for the overhead image. The image composition unit 19 also includes a second virtual vehicle icon acquired by the icon acquisition unit 18 at a position corresponding to the direction coincidence point calculated by the point calculation unit 16 on the overhead view image around the vehicle. That is, the second virtual vehicle icon having a direction that matches the parking direction detected by the parking direction detection unit 14 is superimposed with a size corresponding to the size of the vehicle. Furthermore, the image composition unit 19 has a trajectory icon acquired by the icon acquisition unit 18 at the position corresponding to the predicted travel trajectory calculated by the predicted travel trajectory calculation unit 15 on the bird's-eye view image around the host vehicle, that is, the prediction. A trajectory icon with a curvature that matches the predicted travel trajectory calculated by the travel trajectory calculation unit 15 is superimposed. The image signal of the bird's-eye view around the vehicle on which various icons are superimposed by the image composition unit 19 is output to the monitor 5. Thereby, on the bird's-eye view image around the vehicle, the monitor 5 displays the first virtual vehicle icon at the current position of the vehicle, and the second virtual vehicle icon at the point calculated by the point calculation unit 16. Are respectively superimposed, and an image in which a trajectory icon is superimposed along the predicted travel trajectory calculated by the predicted travel trajectory calculation unit 15 is displayed.

[Control unit processing]
FIG. 2 is a flowchart showing a flow of a series of processes executed by the control unit 10 in the parking assistance apparatus of the present embodiment configured as described above. Hereinafter, the outline of the processing in the control unit 10 in the parking assistance apparatus of the present embodiment will be described along the flowchart of FIG.

  The process shown in the flowchart of FIG. 2 is started when the driver of the own vehicle visually recognizes the parking space that is the parking target, stops the own vehicle, and turns on the parking assist activation switch 4. In addition, the stop position of the own vehicle at this time is arbitrary, and it is not necessary to stop at the position determined especially in relation to the parking space.

  When the parking support activation switch 4 is turned on and an activation signal instructing the start of the parking assistance operation is input to the control unit 10, the control unit 10 first, in step S101, displays the images by the four on-vehicle cameras 1a to 1d. Imaging is started, and an image signal of an image of a road surface around the own vehicle captured by each of the in-vehicle cameras 1a to 1d is input.

  Next, in step S <b> 102, the pixels are rearranged so that the captured images of the in-vehicle cameras 1 a to 1 d are images from the viewpoint of looking down the road surface in the vertical direction. In step S103, the captured images of the four in-vehicle cameras 1a to 1d that have undergone the viewpoint conversion process in step S102 are connected to look down from the virtual viewpoint directly above the own vehicle. Create a bird's-eye view image that represents The processes from step S101 to step S103 are repeated according to the imaging cycle of the in-vehicle cameras 1a to 1d, and the latest overhead image is always created in step S103.

  Next, in step S104, image processing is performed on the bird's-eye view image around the own vehicle created in step S103, and it is determined whether or not a parking space serving as a parking target for the vehicle is detected from this bird's-eye view image. Here, while a parking space cannot be detected from the bird's-eye view image around the own vehicle created in step S103, in step S105, only the first virtual vehicle icon is displayed at a position corresponding to the current position of the vehicle on the bird's-eye view image. And the image signal is output to the monitor 5. After that, the bird's-eye view image around the own vehicle is updated with the movement of the own vehicle, and until the parking space is detected in step S104, the surroundings of the own vehicle around the first virtual own vehicle icon are superimposed. An overhead image is displayed on the monitor 5.

  On the other hand, if a parking space is detected from the bird's-eye view around the vehicle in step S104, then in step S106, the longitudinal direction of the parking space is detected, and the longitudinal direction of the parking space is determined as the parking direction in the parking space. Detect as.

  Next, in step S107, the detection signal of the steering angle sensor 2 and the detection signal of the inhibitor switch 3 are read, and the vehicle turns in the traveling direction corresponding to the shift position while maintaining the current steering angle. The predicted travel locus is calculated.

  Next, in step S108, when the host vehicle moves along the predicted travel path calculated in step S107, the direction of the host vehicle coincides with the parking direction detected in step S106 on the predicted travel path. The direction coincidence point which becomes the direction is calculated.

  In step S109, the first virtual vehicle icon is displayed at the position corresponding to the current position of the vehicle on the bird's-eye view around the vehicle created in step S103, and the position corresponding to the direction matching point calculated in step S108. A trajectory icon is superimposed along the second virtual vehicle icon and the predicted travel trajectory calculated in step S <b> 107, and the image signal is output to the monitor 5.

  Thereafter, in step S110, the change in the detection signal of the steering angle sensor 2 is monitored, and when the detection signal of the steering angle sensor 2 has changed, the process returns to step S107 and a new predicted travel locus corresponding to the current steering angle. Further, in step S108, a direction matching point on the new predicted traveling locus is calculated, and the positions of the second virtual vehicle icon and the locus icon on the bird's-eye view around the vehicle are updated.

  On the other hand, if there is no change in the detection signal of the rudder angle sensor 2, various icons are superimposed in step S109 until an off operation of the parking assist activation switch 4 or an off operation of the own vehicle ignition switch is detected in step S111. A bird's-eye view image around the host vehicle is displayed on the monitor 5, and a series of processing is terminated when an off operation of the parking assist activation switch 4 or an off operation of the ignition switch of the host vehicle is detected.

[Specific Example 1 of Operation]
Here, the operation of the parking assistance apparatus according to the present embodiment will be described in detail, taking as an example a case where the host vehicle tries to perform parallel parking in the parking space while retreating.

  First, as shown in FIG. 3, in order to allow the driver of the own vehicle to move backward in the parking space S <b> 1 and to park in parallel, the driver stops the vehicle diagonally to the right of the parking space S <b> 1 and sets the shift lever to the reverse position. Assume that the parking support activation switch 4 is switched on. The parking assistance device of the present embodiment is activated by turning on the parking assistance activation switch 4 and starts capturing images of the surroundings of the vehicle by the in-vehicle cameras 1a to 1d and creating an overhead view image by the control unit 10, A process of detecting the parking space S1 from the overhead image around the created vehicle is performed. Here, it is assumed that the parking space S1 is detected from the overhead image around the host vehicle at the position shown in FIG.

  When the parking space S1 is detected from the bird's-eye view around the host vehicle, the control unit 10 detects the longitudinal direction of the parking space S1 as the parking direction D1, as shown in FIG. 4, and the current steering angle of the host vehicle. The predicted travel locus L and the direction coincidence point P corresponding to the are calculated. Then, an image in which the first virtual vehicle icon, the second virtual vehicle icon, and the trajectory icon are superimposed on the bird's-eye view image around the vehicle is displayed on the monitor 5. Here, the predicted travel locus L and the direction coincidence point P are newly calculated every time the driver of the own vehicle operates the steering wheel and the steering angle of the own vehicle changes, and the second is displayed on the overhead view image around the own vehicle. The display positions of the virtual vehicle icon and the trajectory icon are updated.

  For example, when the driver of the vehicle turns the steering handle to the right, an arcuate locus L11 centering on C11 in FIG. 4 is calculated as the predicted traveling locus, and the position indicated by P11 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle has returned the steering handle a little to the left, an arcuate locus L12 centering on C12 in FIG. 4 is calculated as the predicted traveling locus, and the position indicated by P12 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle further returns the steering handle to the left, an arcuate locus L13 centered on C13 in FIG. 4 is calculated as a predicted traveling locus, and the position indicated by P13 in FIG. Calculated as a direction coincidence point. Note that AP in FIG. 4 is a reference point of the own vehicle for calculating the predicted traveling locus L (L11, L12, L13) and the direction coincidence point P (P11, P12, P13). However, there is no particular limitation as long as it is an arbitrary point within the host vehicle.

  When the predicted travel locus L and the direction coincidence point P calculated by the control unit 10 change according to the operation of the steering handle of the host vehicle, the second virtual vehicle on the bird's-eye view around the host vehicle displayed on the monitor 5 is changed. The positions of the car icon and the track icon change. The driver of the own vehicle refers to the display image of the monitor 5 so that the positions of the second virtual own vehicle icon and the trajectory icon are in an optimal state for parking the own vehicle in parallel in the parking space S1. It is only necessary to start parking by operating the steering handle and fixing the steering handle in that state. In the example shown in FIG. 4, the steering angle at which the predicted travel locus L13 and the direction coincidence point P13 are calculated is in an optimal state for parking the host vehicle in parallel in the parking space S1, so the driver of the host vehicle In this state, the steering handle may be fixed and parking may be started.

  FIG. 5 is a diagram illustrating an example of an image displayed on the monitor 5 when the control unit 10 calculates the predicted travel locus L13 and the direction coincidence point P13 in the example illustrated in FIG. As shown in the image example shown in FIG. 5, the monitor 5 displays a first virtual vehicle icon VM1 indicating the current position of the vehicle and an optimum steering switchback position on the bird's-eye view around the vehicle. An image in which a second virtual vehicle icon VM2 shown and a trajectory icon LM representing the predicted travel trajectory are superimposed is displayed. Here, the second virtual vehicle icon VM2 indicating the optimum steering switchback position is in the same direction as the parking direction D1 in the parking space S1 at a position corresponding to the direction matching point P13 on the bird's-eye view around the vehicle. Is superimposed. In addition, as the trace icon LM, for example, an arc-shaped line that passes through the left front corner that becomes the outermost turning corner of the own vehicle when the own vehicle moves along the predicted traveling locus L13, and the right that becomes the innermost turning corner. An arcuate line passing through the rear corner is superimposed.

  While checking the display image displayed on the monitor 5, the driver of the own vehicle starts the backward running of the own vehicle with the steering handle fixed, and gradually brings the own vehicle closer to the parking space S1. Accordingly, the image displayed on the monitor 5 changes from the image shown in FIG. 5 as the image of FIG. 6, and the first virtual vehicle icon VM1 is changed to the second virtual vehicle icon VM2. Get closer. Thereafter, when the vehicle continues to travel backward, the first virtual vehicle icon VM1 is displayed so as to overlap the second virtual vehicle icon VM2 on the image displayed on the monitor 5. Then, when the host vehicle reaches the direction coincidence point P13, the superimposed display of the second virtual host vehicle icon VM2 and the trajectory icon LM ends as shown in FIG.

  The driver of the own vehicle can recognize that the own vehicle has reached the direction coincidence point P13 by confirming the display image of the monitor 5, and by switching back the steering handle to the neutral position at that position. The host vehicle can be parked in parallel in the correct posture in the parking space S1.

[Specific example 2 of operation]
Next, the operation of the parking assist device of the present embodiment when the vehicle is going to perform parallel parking in the parking space while retreating will be specifically described.

  First, as shown in FIG. 8, the driver of the own vehicle stops the vehicle diagonally to the right side of the parking space S2 and moves the shift lever to the reverse position in order to cause the own vehicle to move backward in the parking space S2 and perform parallel parking. And the parking assistance activation switch 4 is turned on. The parking assistance device of the present embodiment is activated by turning on the parking assistance activation switch 4 and starts capturing images of the surroundings of the vehicle by the in-vehicle cameras 1a to 1d and creating an overhead view image by the control unit 10, A process of detecting the parking space S2 from the overhead image around the created vehicle is performed. Here, it is assumed that the parking space S2 is detected from the bird's-eye view around the vehicle at the position shown in FIG.

  When the parking space S2 is detected from the bird's-eye view around the host vehicle, the control unit 10 detects the longitudinal direction of the parking space S2 as the parking direction D2, as shown in FIG. 9, and the current steering angle of the host vehicle. The predicted travel locus L and the direction coincidence point P corresponding to the are calculated. Then, an image in which the first virtual vehicle icon, the second virtual vehicle icon, and the trajectory icon are superimposed on the bird's-eye view image around the vehicle is displayed on the monitor 5. Here, the predicted travel locus L and the direction coincidence point P are newly calculated every time the driver of the own vehicle operates the steering wheel and the steering angle of the own vehicle changes, and the second is displayed on the overhead view image around the own vehicle. The display positions of the virtual vehicle icon and the trajectory icon are updated.

  For example, in a state where the driver of the vehicle turns the steering handle to the right, an arcuate locus L21 centering on C21 in FIG. 9 is calculated as the predicted traveling locus, and the position indicated by P21 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle has returned the steering handle a little to the left, an arcuate locus L22 centered on C22 in FIG. 9 is calculated as the predicted traveling locus, and the position indicated by P22 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle further returns the steering handle to the left, an arcuate locus L23 centering on C23 in FIG. 9 is calculated as the predicted traveling locus, and the position indicated by P23 in FIG. Calculated as a direction coincidence point. Note that AP in FIG. 9 is a reference point of the own vehicle for calculating the predicted traveling locus L (L21, L22, L23) and the direction coincidence point P (P21, P22, P23). However, there is no particular limitation as long as it is an arbitrary point within the host vehicle.

  When the predicted travel locus L and the direction coincidence point P calculated by the control unit 10 change according to the operation of the steering handle of the host vehicle, the second virtual vehicle on the bird's-eye view around the host vehicle displayed on the monitor 5 is changed. The positions of the car icon and the track icon change. The driver of the own vehicle refers to the display image of the monitor 5 so that the positions of the second virtual own vehicle icon and the trajectory icon are in an optimal state for parking the own vehicle in parallel in the parking space S2. It is only necessary to start parking by operating the steering handle and fixing the steering handle in that state. In the example shown in FIG. 9, the steering angle at which the predicted travel locus L22 and the direction coincidence point P22 are calculated is in an optimal state for parking the vehicle in parallel in the parking space S2. In this state, the steering handle may be fixed and parking may be started.

  FIG. 10 is a diagram illustrating an example of an image displayed on the monitor 5 when the control unit 10 calculates the predicted travel locus L22 and the direction coincidence point P22 in the example illustrated in FIG. As in the image example shown in FIG. 10, the monitor 5 displays a first virtual vehicle icon VM1 indicating the current position of the vehicle and an optimum steering switchback position on the overhead view image around the vehicle. An image in which a second virtual vehicle icon VM2 shown and a trajectory icon LM representing the predicted travel trajectory are superimposed is displayed. Here, the second virtual vehicle icon VM2 indicating the optimum steering switchback position is in the same direction as the parking direction D2 in the parking space S2 at a position corresponding to the direction matching point P22 on the bird's-eye view image around the vehicle. Is superimposed. The trajectory icon LM includes, for example, an arc-shaped line that passes through the left front corner that is the outermost turning corner of the own vehicle when the own vehicle moves along the predicted traveling locus L22, and the right that is the innermost turning corner. An arcuate line passing through the rear corner is superimposed.

  While checking the display image displayed on the monitor 5, the driver of the own vehicle starts the backward running of the own vehicle with the steering handle fixed, and gradually brings the own vehicle closer to the parking space S2. Accordingly, the image displayed on the monitor 5 changes from the image shown in FIG. 10 to the image shown in FIG. 11, and the first virtual vehicle icon VM1 is changed to the second virtual vehicle icon VM2. Get closer. Thereafter, when the vehicle continues to travel backward, the first virtual vehicle icon VM1 is displayed so as to overlap the second virtual vehicle icon VM2 on the image displayed on the monitor 5. When the host vehicle reaches the direction coincidence point P22, the superimposed display of the second virtual host vehicle icon VM2 and the trajectory icon LM ends as shown in FIG.

  The driver of the own vehicle can recognize that the own vehicle has reached the direction coincidence point P22 by confirming the display image of the monitor 5, and by switching back the steering handle to the neutral position at that position. The host vehicle can be parked in parallel in the correct posture in the parking space S2.

[Specific example 3 of operation]
Next, in a narrow area where the driving of the vehicle is restricted by obstacles such as walls and other vehicles, when the vehicle tries to park in parallel in the parking space, it turns back and parks after moving forward The operation of the parking assistance apparatus according to the present embodiment when attempting to do this will be specifically described.

  First, as shown in FIG. 13, the driver of the own vehicle turns back and once advances the own vehicle and then moves backward to park in parallel in the parking space S <b> 3. Assume that the parking support activation switch 4 is turned on by switching the shift lever to the drive position. The parking assistance device of the present embodiment is activated by turning on the parking assistance activation switch 4 and starts capturing images of the surroundings of the vehicle by the in-vehicle cameras 1a to 1d and creating an overhead view image by the control unit 10, A process of detecting the parking space S3 from the created overhead view around the vehicle is performed. Here, it is assumed that the parking space S3 is detected from the overhead image around the host vehicle at the position shown in FIG.

  When the parking space S3 is detected from the bird's-eye view around the host vehicle, the control unit 10 detects the longitudinal direction of the parking space S3 as the parking direction D3 as shown in FIG. 14, and the current steering angle of the host vehicle. The predicted travel locus L and the direction coincidence point P corresponding to the are calculated. In this example, since the shift position of the host vehicle is the drive position, the trajectory when the host vehicle turns forward while maintaining the current steering angle is calculated as the predicted travel track L. A point where the direction of the host vehicle coincides with the parking direction C3 on the predicted traveling locus L ahead of the vehicle is calculated as the direction coincidence point P. Then, an image in which the first virtual vehicle icon, the second virtual vehicle icon, and the trajectory icon are superimposed on the bird's-eye view image around the vehicle is displayed on the monitor 5. Here, the predicted travel locus L and the direction coincidence point P are newly calculated every time the driver of the own vehicle operates the steering wheel and the steering angle of the own vehicle changes, and the second is displayed on the overhead view image around the own vehicle. The display positions of the virtual vehicle icon and the trajectory icon are updated.

  For example, in a state where the driver of the own vehicle turns the steering handle to the right, an arcuate locus L31 centering on C31 in FIG. 14 is calculated as the predicted traveling locus, and the position indicated by P31 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle has returned the steering handle a little to the left, an arcuate locus L32 centered on C32 in FIG. 14 is calculated as the predicted traveling locus, and the position indicated by P32 in FIG. Calculated as a direction coincidence point. Further, in a state where the driver of the own vehicle further returns the steering handle to the left, an arcuate locus L33 centering on C33 in FIG. 14 is calculated as the predicted traveling locus, and the position indicated by P33 in FIG. Calculated as a direction coincidence point. Note that AP in FIG. 14 is a reference point of the own vehicle for calculating the predicted traveling locus L (L31, L32, L33) and the direction coincidence point P (P31, P32, P33). However, there is no particular limitation as long as it is an arbitrary point within the host vehicle.

  When the predicted travel locus L and the direction coincidence point P calculated by the control unit 10 change according to the operation of the steering handle of the host vehicle, the second virtual vehicle on the bird's-eye view around the host vehicle displayed on the monitor 5 is changed. The positions of the car icon and the track icon change. The driver of the own vehicle can refer to the display image of the monitor 5 so that the position of the second virtual own vehicle icon can be parked in parallel in the correct posture in the parking space S3 while moving the vehicle straight backward. It is only necessary to operate the steering wheel so that the vehicle is in the right position, and to fix the steering wheel in that state to advance the vehicle. In the example shown in FIG. 14, the steering angle at which the predicted travel locus L32 and the direction coincidence point P32 are calculated is an optimal state in which the vehicle is moved to an ideal position for parallel parking in the parking space S3 in the correct posture. Therefore, the driver of the own vehicle may advance the own vehicle by fixing the steering handle in that state.

  FIG. 15 is a diagram illustrating an example of an image displayed on the monitor 5 when the control unit 10 calculates the predicted travel locus L32 and the direction coincidence point P32 in the example illustrated in FIG. As shown in the image example in FIG. 15, the monitor 5 includes a first virtual vehicle icon VM1 representing the current position of the vehicle and an optimum steering switchback position on the bird's-eye view around the vehicle. An image in which a second virtual vehicle icon VM2 shown and a trajectory icon LM representing the predicted travel trajectory are superimposed is displayed. Here, the second virtual vehicle icon VM2 indicating the optimum steering switchback position is in the same direction as the parking direction D3 in the parking space S3 at a position corresponding to the direction matching point P32 on the overhead view image around the vehicle. Is superimposed. In addition, as the track icon LM, for example, an arc-shaped line through which the left front corner that becomes the outermost turning corner of the vehicle when the vehicle moves along the predicted travel track L32 is superimposed.

  While checking the display image displayed on the monitor 5, the driver of the host vehicle advances the host vehicle with the steering handle fixed. Accordingly, the image displayed on the monitor 5 changes from the image shown in FIG. 15 to the image shown in FIG. 16, and the first virtual vehicle icon VM1 is changed to the second virtual vehicle icon VM2. Get closer. Thereafter, when the vehicle continues to move forward, the first virtual vehicle icon VM1 is displayed so as to overlap the second virtual vehicle icon VM2 on the image displayed on the monitor 5. When the host vehicle reaches the direction coincidence point P32, as shown in FIG. 17, the superimposed display of the second virtual host vehicle icon VM2 and the trajectory icon LM ends.

  The driver of the own vehicle can recognize that the own vehicle has reached the direction coincidence point P32 by checking the display image on the monitor 5, and at that position, the steering wheel is turned back to the neutral position and the shift lever Is switched to the reverse position and the host vehicle is caused to travel backward straight, whereby the host vehicle can be parked in parallel in the correct posture in the parking space S3 as shown in FIG. FIG. 18 is a display image displayed on the monitor 5 when the vehicle is parked in parallel in the parking space S3.

[Effect of the embodiment]
As described above, the parking support device according to the present embodiment captures images around the host vehicle with the in-vehicle cameras 1a to 1d, and determines the parking target of the host vehicle from the image around the host vehicle. The parking space S and the parking direction D in the parking space S are detected. Further, a predicted travel locus L when the host vehicle turns while maintaining the current steering angle is calculated, and the direction of the host vehicle is the same as the parking direction D in the parking space S on the predicted travel track L. The direction coincidence point P which is a point to be calculated is calculated. Then, the first virtual vehicle icon VM1 corresponding to the size of the vehicle is superimposed on the position corresponding to the current position of the vehicle on the image around the vehicle, and the direction coincides on the image around the vehicle. A second virtual vehicle icon VM2 corresponding to the size of the vehicle is superimposed at the position corresponding to the point P in the same direction as the parking direction D in the parking space S, and the first virtual vehicle icon VM1 and An image around the vehicle on which the second virtual vehicle icon VM2 is superimposed is displayed on the monitor 5. Accordingly, the driver of the own vehicle performs steering switchback when the first virtual vehicle icon VM1 overlaps the second virtual vehicle icon VM2 while viewing the image displayed on the monitor 5. The own vehicle can be parked in the parking space S with the correct posture. As described above, according to the parking assist device of the present embodiment, the driver of the vehicle can determine whether the vehicle can be parked so as not to be inclined in the parking space S when the steering is switched back. It is possible to accurately recognize the vehicle and to appropriately support the driving operation during parking by the driver of the vehicle so that the vehicle can be parked in the correct posture in the parking space S.

  Moreover, according to the parking assistance apparatus of this embodiment, the traveling direction of the own vehicle is determined from the detection signal of the inhibitor switch 3, and the prediction when the own vehicle turns in the traveling direction while maintaining the current steering angle. Since the travel locus L is calculated, it is possible to accurately recognize the point where the steering should be switched back in the direction intended by the driver of the host vehicle.

  Moreover, according to the parking assistance device of the present embodiment, the captured images of the in-vehicle cameras 1a to 1d are viewpoint-converted and connected to create an overhead image in which the entire periphery of the own vehicle is looked down from the virtual viewpoint above the own vehicle. Since the first virtual vehicle icon VM1 and the second virtual vehicle icon VM2 are superimposed on the bird's-eye view image around the vehicle and displayed on the monitor 5, the direction matching point P and the parking space S are displayed. It is possible for the driver of the own vehicle to intuitively grasp the positional relationship between the vehicle position and the own vehicle position, and it is possible to more effectively support the driving operation during parking by the driver of the own vehicle.

  Further, according to the parking assist device of the present embodiment, a tangent line that is in contact with the predicted traveling locus L according to the current steering angle of the host vehicle and that is parallel to the parking direction D in the parking space S is obtained. Since the contact point with the predicted traveling locus L is calculated as the direction coincidence point P, the direction coincidence point P can be calculated easily and accurately.

  Moreover, according to the parking assistance apparatus of this embodiment, the frame figure corresponding to the outer periphery shape of the own vehicle is superimposed on the image around the own vehicle and displayed on the monitor 5 as the second virtual own vehicle icon VM1. Therefore, the driver can accurately recognize the posture of the vehicle at the direction matching point P, and the first virtual vehicle icon VM1 and the second virtual vehicle made up of computer graphics images simulating the vehicle. It is possible to prevent confusion with the vehicle icon VM2 and to display an easy-to-understand image on the monitor 5.

  In addition, according to the parking assistance device of the present embodiment, in addition to the first virtual vehicle icon VM1 and the second virtual vehicle icon VM2, a track icon representing the predicted travel track L on the image around the vehicle. Since the LM is superimposed and displayed on the monitor 5, the behavior of the vehicle at the time of parking can be easily recognized by the driver. Further, as the trajectory icon LM, an arc-shaped line passing through at least the outermost part of the turning when the host vehicle travels along the predicted traveling track L is superimposed on the image around the host vehicle and displayed on the monitor 5. In this way, it is possible to make the driver accurately recognize whether or not there is a possibility of interference with an obstacle.

  In order to make the driver recognize the behavior of the vehicle at the time of parking in an easy-to-understand manner, as the track icon LM, an arc-shaped path passing through the portion that becomes the outermost turning corner when the vehicle travels along the predicted travel track L is used. It is effective to display on the monitor 5 both the line and the arc-shaped line passing through the innermost part of the turn on the image around the vehicle. However, if the trajectory icon LM is displayed in this way when the vehicle approaches the direction coincidence point P, there is a concern that the display becomes complicated and the visibility decreases. Therefore, in a state where the own vehicle is separated from the direction coincidence point P by a predetermined distance or more, as a trajectory icon LM, an arc-shaped line passing through a portion that is the outermost periphery of turning and an arc-shaped line passing through a portion that is the innermost periphery of turning Both are displayed on the monitor 5 and after the distance from the own vehicle to the direction coincidence point P becomes less than a predetermined distance, only the arc-shaped line passing through the part that is the outermost periphery of the turn is displayed on the monitor 5 as the trajectory icon LM. You may make it display. Thereby, it is possible to make the driver recognize the behavior of the vehicle at the time of parking more easily while effectively preventing the display of the monitor 5 from being complicated.

  Moreover, according to the parking assistance apparatus of this embodiment, when detecting the parking direction D in the parking space S which is the parking target of the own vehicle, the longitudinal direction of the parking space S is detected by analyzing the image around the own vehicle. And since the longitudinal direction of this parking space S is detected as the parking direction D, the detection of the parking direction D can be performed reliably and simply.

  Moreover, according to the parking assistance apparatus of this embodiment, when the own vehicle reaches the direction coincidence point P, the superimposed display of the second virtual own vehicle icon VM2 is terminated. It is possible to effectively prevent the display from becoming complicated due to the display of the second virtual vehicle icon VM2 being continued.

  The embodiment described above is an example of application of the present invention, and the technical scope of the present invention is not intended to be limited to the contents described in each of the above embodiments. That is, the technical scope of the present invention is not limited to the specific technical matters disclosed in the above embodiments, but includes various modifications, changes, alternative techniques, and the like that can be easily derived from this disclosure.

  For example, in the above-described embodiment, viewpoints of images captured by the four in-vehicle cameras 1a to 1d are converted and connected to create an overhead image in which the entire periphery of the own vehicle is looked down from a virtual viewpoint above the own vehicle. The first virtual vehicle icon VM1, the second virtual vehicle icon VM2, and the trajectory icon LM are superimposed on the bird's-eye view image around the vehicle and displayed on the monitor 5, but the in-vehicle cameras 1a to 1d Using the captured images as they are, the first virtual vehicle icon VM1, the second virtual vehicle icon VM2, and the trajectory icon LM are superimposed on the captured images of the in-vehicle cameras 1a to 1d and displayed on the monitor 5. May be. In addition, the first virtual vehicle icon VM1, the second virtual vehicle icon VM2, and the trajectory icon LM are superimposed on an image captured by a single camera installed at a high position of the vehicle and displayed on the monitor 5. You may make it make it.

  Further, in the above-described embodiment, an image in which the position of the parking space S is fixed on the bird's-eye view around the host vehicle and the position of the first virtual host vehicle icon VM1 moves as the host vehicle moves is displayed on the monitor 5. Although displayed, the position of the first virtual vehicle icon VM1 is fixed on the bird's-eye view around the vehicle, and an image in which the surrounding image including the parking space S changes as the vehicle moves is monitored. 5 may be displayed.

It is a block diagram which shows the structure of the parking assistance apparatus to which this invention is applied. It is a flowchart which shows the flow of the process performed by a control unit. It is a figure explaining operation | movement of the parking assistance apparatus in the case of trying to carry out parallel parking in a parking space, while the own vehicle reverses, and shows the positional relationship between the own vehicle and the parking space when the parking assistance start switch is turned on It is. It is a figure explaining how to calculate a predicted traveling locus and a direction coincidence point. It is a figure which shows an example of the display image displayed on a monitor in the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle reverse | retreats from the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle reaches | attains a direction coincidence point. It is a figure explaining operation of a parking assistance device when trying to perform parallel parking in a parking space while the own vehicle is moving backward, and shows a positional relationship between the own vehicle and the parking space when a parking assistance activation switch is turned on. It is. It is a figure explaining how to calculate a predicted traveling locus and a direction coincidence point. It is a figure which shows an example of the display image displayed on a monitor in the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle reverse | retreats from the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle reaches | attains a direction coincidence point. It is a figure explaining the operation of the parking assistance device when the vehicle is going to park in parallel in the parking space, and once turning back and moving forward and then going backward to park, the parking assistance activation switch is turned on It shows the positional relationship between the vehicle and the parking space when it is done. It is a figure explaining how to calculate a predicted traveling locus and a direction coincidence point. It is a figure which shows an example of the display image displayed on a monitor in the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle advances from the position of FIG. It is a figure which shows an example of the display image displayed on a monitor when the own vehicle reaches | attains a direction coincidence point. It is a figure which shows an example of the display image displayed on a monitor, when the own vehicle retreats straight from a direction matching point and arrives at a parking space.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a-1d Car-mounted camera 2 Steering angle sensor 3 Inhibitor switch 5 Monitor 10 Controller 11 View point conversion part 12 Overhead image creation part 13 Parking space detection part 14 Parking direction detection part 15 Predicted driving | running | working locus calculation part 16 Point calculation part 19 Image composition part 19

Claims (1)

A camera that captures images of the area around the vehicle,
Parking space detecting means for detecting a parking space from the image around the vehicle;
Parking direction detecting means for detecting a parking direction in the parking space;
A rudder angle sensor that detects the current steering angle of the vehicle,
Traveling direction detection means for detecting the traveling direction of the host vehicle;
Based on the detected value of the rudder angle sensor, a predicted travel locus calculating means for calculating a predicted travel locus when the vehicle turns in the traveling direction while maintaining the current steering angle;
A point calculating means for calculating a point on the predicted traveling locus and the direction of the own vehicle is the same direction as the parking direction detected by the parking direction detecting means;
A first virtual vehicle icon corresponding to the size of the vehicle is superimposed on a position corresponding to the current position of the vehicle on the image around the vehicle, and the point calculation on the image around the vehicle is performed. A second virtual vehicle icon corresponding to the size of the vehicle is superimposed at a position corresponding to the point calculated by the vehicle in the same direction as the parking direction detected by the parking direction detection unit, and the vehicle Image composition means for superimposing a trajectory icon representing the predicted travel trajectory on a surrounding image;
A monitor for displaying an image around the vehicle in which the first virtual vehicle icon, the second virtual vehicle icon, and the trajectory icon are superimposed by the image composition unit;
An image conversion means for converting an image captured by the camera into a bird's-eye view image looking down from a virtual viewpoint above the host vehicle, and
The image synthesizing unit superimposes the first virtual vehicle icon, the second virtual vehicle icon, and a trajectory icon on the image around the vehicle converted into the overhead image by the image conversion unit,
The image composition means superimposes a frame figure corresponding to the outer peripheral shape of the vehicle on the image around the vehicle as the second virtual vehicle icon,
The point calculating means obtains a tangent that is in contact with the predicted traveling locus and parallel to the parking direction detected by the parking direction detecting means, and calculates a contact point between the tangent and the predicted traveling locus as the point,
The image synthesizing unit displays, as a trajectory icon representing the predicted travel trajectory, an arc-shaped line passing through a portion that is the outermost turning corner when the vehicle turns while maintaining the current steering angle. Superimposed on
The parking direction detection means analyzes an image around the vehicle and recognizes the longitudinal direction of the parking space, detects the longitudinal direction of the parking space as the parking direction,
When the current position of the vehicle has reached the point calculated by the point calculation unit, the image composition unit ends the superimposition of the second virtual vehicle icon ,
When the distance from the current position of the host vehicle to the point calculated by the point calculation unit is equal to or greater than a predetermined value, the image synthesizing unit displays the current steering angle as a track icon representing the predicted travel track. Maintaining the current position of the vehicle by superimposing an arc-shaped line that passes through the portion that becomes the outermost periphery of the turn and a circular line that passes through the portion that becomes the innermost periphery when turning while maintaining a turn If the distance from the point to the point calculated by the point calculating means is less than the predetermined value, the outermost turning corner when the vehicle turns while maintaining the current steering angle as the locus icon representing the predicted traveling locus A parking assist device , wherein an arcuate line passing through a portion to be superimposed on an image around the vehicle .

Images