JP6559083B2 - Parking assistance device and parking assistance method - Google Patents

Description

  The present invention relates to a parking assistance device and a parking assistance method that display an image of the rear imaged when a vehicle moves backward.

  Conventionally, when the vehicle is moved backward, the predicted trajectory of the vehicle is displayed until the vehicle is parallel to the left and right white lines of the parking frame, and when the vehicle is parallel, the display of the predicted trajectory is stopped. There is known a parking assist device that displays the steering angle of the steering wheel at that time and the steering direction of the steering wheel for making the wheels parallel to the vehicle body (see Patent Document 1).

  In addition, when the vehicle is moved backward and parked parallel to the parking frame, auxiliary information presentation is made so that the predicted trajectory of the vehicle is displayed superimposed on the rear image when the rear direction of the vehicle approaches the parking frame. An apparatus is known (for example, refer to Patent Document 2).

JP 2011-230615 A JP 2005-335444 A

  By the way, in the parking assistance apparatus disclosed in Patent Document 1 described above, when the left and right white lines of the parking frame become parallel to the vehicle when the vehicle is moved backward, the display of the expected trajectory of the vehicle disappears. Since the display of the steering angle and steering direction of the steering wheel is started, even if the steering wheel is operated at that time, the vehicle will exceed the parallel position. For this reason, it is necessary to finely adjust the direction and position of the vehicle, and there is a problem that the vehicle cannot be parked quickly and accurately in the parking frame.

  In addition, in the devices disclosed in Patent Document 1 and Patent Document 2 described above, driving itself to retreat the vehicle so as to be parallel to the left and right white lines of the parking frame relies on the experience and intuition of the driver, Since the guidance information until the vehicle is parallel to the white line is not provided, there is a problem that the vehicle cannot be parked in the parking frame quickly and accurately from this point.

  The present invention has been created in view of such a point, and an object of the present invention is to provide a parking assistance device and a parking assistance method capable of quickly and accurately parking a vehicle in a parking frame.

  In order to solve the above-described problem, a parking assist device according to the present invention includes an imaging unit that captures an image of the rear of a host vehicle including a road surface, and a parking frame that includes a parking frame included in a captured image obtained by imaging by the imaging unit. Based on the frame extraction means, the steering angle detection means for detecting the steering angle of the own vehicle, and the movement locus for predicting the movement locus of the rear wheel when the own vehicle moves backward based on the steering angle detected by the steering angle detection means Prediction means, parallel position specifying means for specifying the position of the rear wheel on the movement trajectory where the left and right white lines constituting the parking frame and the own vehicle are parallel, and the own vehicle retreated along the movement trajectory In this case, after the position specified by the parallel position specifying means disappears from the road surface included in the captured image, the guide information presenting means for presenting the guide information until the rear wheel reaches the position specified by the parallel position specifying means; With That.

  In addition, the parking assist method of the present invention includes a parking frame extraction step of extracting a parking frame included in a captured image obtained by imaging by an imaging unit that images the back of the host vehicle including the road surface, Based on the steering angle detecting step for detecting the steering angle of the vehicle by the steering angle detecting means and the steering angle detected by the steering angle detecting means, the movement trajectory of the rear wheel when the host vehicle moves backward is determined by the movement trajectory predicting means. A predicting movement trajectory step, a parallel position specifying step of specifying a position of a rear wheel on the moving trajectory where the left and right white lines constituting the parking frame and the host vehicle are parallel by the parallel position specifying means, When the vehicle moves backward along the movement trajectory, the rear wheel is moved by the parallel position specifying unit after the position specified by the parallel position specifying unit disappears from the road surface included in the captured image. And a guidance information presenting step of presenting the guiding information presentation means guidance information up to the specified position.

  Since the guidance information to the position where the left and right white lines of the parking frame and the host vehicle are parallel (parallel position) is presented, it is parallel to the road surface in the captured image when the host vehicle moves backward and approaches the parallel position. Even when the position is lost, the driver can know how much the vehicle is moved backward to reach the parallel position, and can quickly and accurately park the vehicle in the parking frame.

Further, the guidance information presenting means described above is a first moving distance that is a moving distance of the rear wheel from the time point when the position specified by the parallel position specifying means disappears from the road surface included in the captured image to the time point of interest. A guide image showing a ratio between a position of the rear wheel at the time of interest and a second movement distance that is a distance from the position of the rear wheel to the position specified by the parallel position specifying means. Do. As a result, the degree of approach of the host vehicle to the parallel position can be presented to the driver in an easily understandable manner.

  In addition, the movement locus drawing means for drawing the movement locus described above, the movement locus drawn by the movement locus drawing means on the captured image obtained by imaging by the imaging means, and the guide image drawn by the guidance information presentation means It is desirable to further include a rear image display processing means for displaying the images in a superimposed manner. By displaying the movement trajectory and the guidance information superimposed on the captured image, it is possible to inform the driver not only of the degree of approach of the host vehicle to the parallel position but also the situation behind the vehicle when reversing.

  Further, the above-described guide image is a backline having a shape imitating the contour of the rear vehicle shape from the rear wheel of the vehicle, and is a backline indicating a ratio of the first movement distance and the second movement distance. It is desirable. A technique of displaying a backline superimposed on a rear image is generally used. By using such a backline as a guide image of the present invention, effective information can be obtained without adding a new display element. Can be presented.

  The guide image described above includes a first index having a length and a color corresponding to the first movement distance, and a second index having a length and a color corresponding to the second movement distance. It is desirable. As a result, the driver can quickly grasp the degree of approach of the host vehicle to the parallel position visually.

  Moreover, it is desirable that the above-described guidance information presenting unit terminates the presentation of the guidance information when the rear wheel reaches the position specified by the parallel position specifying unit. As a result, the driver can be surely informed that the vehicle has reached the parallel position. At that time, the steering angle of the steering wheel is returned to the original position (straight-running state). The vehicle can be retreated in parallel along

  The guidance information presenting means described above outputs guidance information indicating that the rear wheel is approaching the position specified by the parallel position specifying means and that the rear wheel has reached this position. It is desirable to present. By notifying the time when the host vehicle approaches and reaches the parallel position by voice, the driver can quickly and accurately park the vehicle in the parking frame.

It is a figure which shows the structure of the parking assistance apparatus of one Embodiment. It is a figure which shows the example of a drawing of a movement locus | trajectory. It is a figure which shows the example of drawing of a back line. It is a flowchart which shows the operation | movement procedure of the display process of the back image at the time of setting the position of a shift lever to rear. It is a figure which shows the other example of a guidance image.

  Hereinafter, a parking assistance device according to an embodiment to which the present invention is applied will be described with reference to the drawings.

  Drawing 1 is a figure showing the composition of the parking assistance device of one embodiment. As shown in FIG. 1, the parking assist device 1 of the present embodiment includes a rear camera 10, an image memory 12, a parking frame extraction unit 20, a steering angle detection unit 22, a movement trajectory prediction unit 24, a parallel position specification unit 26, and a parallel. A position disappearance determination unit 28, a movement distance calculation unit 30, a movement locus drawing unit 32, a backline drawing unit 34, a rear image display processing unit 36, and a display device 38 are provided.

  The parking assist device 1 is mounted on a vehicle, and when the position of the shift lever is set to the rear, a rear image obtained by imaging the rear of the vehicle is displayed on a screen in the passenger compartment and when the vehicle is moved backward. Then, an operation for displaying guidance information for guiding the vehicle to a position where the vehicle is parallel to the movement trajectory and the left and right white lines of the parking frame is performed on the rear image.

  The rear camera 10 is attached to the rear of the vehicle and images the imaging range behind the host vehicle including the road surface. For example, it is desirable to use a camera having a wide angle of view by using a CCD image sensor or a CMOS image sensor and attaching a wide-angle lens such as a fisheye lens. The image memory 12 stores an image obtained by imaging with the rear camera 10 at a predetermined frame rate (for example, 30 frames / second).

  The parking frame extraction unit 20 extracts a parking frame included in the rear image stored in the image memory 12. The parking frame includes at least white lines parallel to the left and right of the vehicle when the vehicle is parked.

  The steering angle detector 22 detects the steering angle of the vehicle (the steering operation angle).

  The movement locus prediction unit 24 predicts (calculates) the movement locus of the rear wheels when the vehicle is moved backward based on the steering angle detected by the steering angle detection unit 22, the wheelbase length of the host vehicle, and the like.

  The parallel position specifying unit 26 is a rear wheel on the movement trajectory calculated by the movement trajectory prediction unit 24 and in which the left and right white lines constituting the parking frame extracted by the parking frame extraction unit 20 are parallel to the host vehicle. (Hereinafter, this position is referred to as “parallel position”).

  The parallel position disappearance determination unit 28 determines whether the parallel position has disappeared from the road surface included in the rear image stored in the image memory 12 when the host vehicle retreats along the travel trajectory calculated by the travel trajectory prediction unit 24. Determine whether or not.

  The movement distance calculation unit 30 is configured so that the parallel position disappearance determination unit 28 determines that the parallel position has disappeared, and then the rear wheel travel distance (first travel distance) from the point of disappearance to the point of interest. The distance from the rear wheel position to the parallel position at the time of interest (second movement distance) and the ratio thereof are calculated.

  When displaying the backward image stored in the image memory 12, the movement locus drawing unit 32 draws the movement locus calculated by the movement locus prediction unit 24 on the road surface included in the backward image. For example, the movement trajectory is drawn using a line of a color (for example, red) that can be distinguished from the back image as the background. Further, when a parallel position is included on the movement locus, a movement locus in which an image serving as a specific index (hereinafter, this image is referred to as a “parallel mark”) is added to the parallel position.

  FIG. 2 is a diagram illustrating a drawing example of the movement trajectory. FIG. 2 shows a drawing example of a movement trajectory displayed superimposed on the rear image. This rear image includes the left and right white lines W1 and W2 constituting the parking frame, and the movement locus T1 including the parallel mark P1 and the movement locus T2 including the parallel mark P2 are drawn in an overlapping manner. Yes.

  When displaying the rear image stored in the image memory 12, the backline drawing unit 34 draws a backline (guidance information) having a shape imitating the contour of the rear vehicle shape from the rear wheel of the vehicle. For example, a U-shaped line indicating a position of about 90 cm behind the vehicle is used for the back line. In addition, the first region closer to the vehicle of the U-shaped line is color-coded to correspond to the first movement distance described above, and the second region far from the vehicle corresponds to the second movement distance described above. Thus, the ratio of the first and second movement distances can be known.

  FIG. 3 is a diagram illustrating a backline drawing example. FIG. 3 shows a drawing example of the movement trajectories T1 and T2 and the backline B displayed so as to be superimposed on the rear image. A backline including the first region b1 and the second region b2 is drawn on the rear image so as to overlap. The first area b1 included in the back line B corresponds to the first index, and the second area b2 corresponds to the second index. By confirming that the second region b2 is included in the backline B, the driver can know that the rear wheel of the host vehicle has not reached the positions of the parallel marks P1 and P2. At the same time, it is possible to know how much the host vehicle is moved backward thereafter to reach the positions of the parallel marks P1 and P2.

  The rear image display processing unit 36 reads the rear image stored in the image memory 12 and displays the rear image on the screen of the display device 38, and the movement locus or parallel mark drawn by the movement locus drawing unit 32 or the backline drawing unit 34. The back line drawn by the above is superimposed on the rear image and displayed on the screen of the display device 38. The display device 38 is provided in front of the driver's seat or between the driver's seat and the passenger seat, and is configured by an LCD, for example. As the display device 38, it may be possible to use a display device used in a navigation device or the like, but it may be provided exclusively.

  The rear camera 10 described above is an imaging unit, the parking frame extraction unit 20 is a parking frame extraction unit, the steering angle detection unit 22 is a steering angle detection unit, the movement track prediction unit 24 is a movement track prediction unit, and a parallel position specifying unit. 26 is a parallel position specifying unit, a moving distance calculating unit 30, a backline drawing unit 34 is a guidance information presenting unit, a moving track drawing unit 32 is a moving track drawing unit, and a rear image display processing unit 36 is a rear image display processing unit. Correspond to each.

  The parking assistance apparatus 1 of the embodiment has such a configuration, and the operation thereof will be described next.

  FIG. 4 is a flowchart showing the operation procedure of the rear image display process when the position of the shift lever is set to the rear. For example, this operation procedure is repeated every imaging interval (for example, 1/30 second) by the rear camera 10.

  When the rear camera 10 captures an imaging range behind the host vehicle including the road surface, and the captured rear image is stored in the image memory 12 (step 100), the parking frame extraction unit 20 is included in the stored rear image. The parking frame to be extracted is extracted (step 102). For example, when there are two white lines that have an interval in consideration of the width of the vehicle (180 cm + α) and are parallel to each other, these white lines are extracted as parking frames. The rear image is an image of the road surface taken diagonally downward through a wide-angle lens and is distorted. When performing parking frame extraction, etc., it is converted to a top view image to remove the effects of this distortion. You may make it carry out based on the image after doing.

  Next, the steering angle detector 22 detects the steering angle of the vehicle (step 104). This detection operation may be performed before or after the operation of steps 100 and 102 described above, or in parallel.

  Next, the movement trajectory prediction unit 24 predicts (calculates) the movement trajectory of the rear wheels when the host vehicle is moved backward while maintaining the current steering angle (step 106). Further, the parallel position specifying unit 26 determines whether or not the parking frame extracted in Step 102 exists (Step 108). If there is a parking frame, an affirmative determination is made. Next, the parallel position specifying unit 26 is located on the movement trajectory predicted in Step 106 and the position of the rear wheel where the left and right white lines constituting the parking frame extracted in Step 102 are parallel to the host vehicle ( (Parallel position) is specified (step 110). In addition, the parallel position specifying unit 26 determines whether or not the specified parallel position is within the parking frame (step 112). If the parallel position is within the parking frame, an affirmative determination is made. Next, the parallel position specifying unit 26 determines whether or not the specified parallel position has disappeared from the road surface included in the imaging range (rear image) (step 114).

  If the parallel position has not disappeared from the road surface within the imaging range, a negative determination is made. In this case, the movement trajectory drawing unit 32 draws the movement trajectory T1 including the parallel mark P1 and the movement trajectory T2 including the parallel mark P2 so as to correspond to each of the two rear wheels (step 116). . As shown in FIG. 2, the rear image display processing unit 36 superimposes the movement trajectories T1 and T2 with the parallel marks P1 and P2 drawn in step 116 on the rear image stored in the image memory 12, and displays the display device 38. (Step 124).

  If the parallel position disappears from the road surface within the imaging range, an affirmative determination is made in the determination of step 114. In this case, the backline drawing unit 34 determines whether or not the rear wheel has reached the parallel position (step 118). If not, a negative determination is made.

  Next, the movement distance calculation unit 30 performs the movement distance (first movement distance) of the rear wheel from the time point when the parallel position disappears from the road surface to the time point of interest by the parallel position specifying unit 26 from the rear wheel position at the time point of interest. The distance to the specified parallel position (second movement distance) and the ratio thereof are calculated, and the backline drawing unit 30 draws the colored backline B reflecting these ratios (step 120). . The movement locus drawing unit 32 draws a movement locus T1 that does not include the parallel mark P1 and a movement locus T2 that does not include the parallel mark P2 so as to correspond to each of the two rear wheels (step 122). . As shown in FIG. 3, the rear image display processing unit 36 adds the backline B drawn in step 120 and the parallel marks P1 and P2 drawn in step 122 to the rear image stored in the image memory 12. The movement trajectories T1 and T2 are overlapped and displayed on the screen of the display device 38 (step 124).

  If the rear wheel has reached the parallel position, an affirmative determination is made in step 118. In this case, the back line is not drawn in step 120, and the rear image in which the movement trajectories T1, T2 without the parallel marks P1, P2 are superimposed is displayed (steps 122, 124). In other words, the backline is displayed until the rear wheel reaches the parallel position, but when it reaches, the backline display disappears, so when the backline display disappears, the driver moves the steering wheel to the straight position. Thereafter, the host vehicle can be moved backward while maintaining the parallel state of the host vehicle and the parking frame.

  Step 120 is also performed when there is no parking frame (left and right white lines) within the imaging range (negative determination in the determination of step 108) or when the parallel position is not within the parking frame (negative determination in the determination of step 112). The back image is not drawn, and a rear image in which the movement trajectories T1, T2 without the parallel marks P1, P2 are superimposed is displayed (steps 122, 124).

  Thus, in the parking assistance apparatus 1 according to the present embodiment, the back line as the guidance information up to the position (parallel position) where the left and right white lines of the parking frame and the own vehicle are parallel is presented. Even if the parallel position disappears from the road surface in the captured image (rear image) when the vehicle moves backward and approaches the parallel position, the driver can determine how much the vehicle should move backward to reach the parallel position. The vehicle can be parked in the parking frame quickly and accurately.

  In addition, as a backline, an image showing a ratio between the first movement distance from the rear wheel to the parallel position after the parallel position disappears from the road surface included in the captured image and the second movement distance from the rear wheel to the parallel position. By using it, the degree of approach of the host vehicle to the parallel position can be presented to the driver in an easy-to-understand manner.

  In addition, by displaying the captured image with the movement locus and the back line superimposed, it is possible to notify the driver not only of the degree of approach of the host vehicle to the parallel position but also the situation behind the vehicle when reversing.

  In particular, a method of displaying a backline superimposed on a captured image (rear image) is generally used, and by using such a backline as a guide image of the present invention, without adding a new display element, Effective information can be presented to the driver.

  In addition, the back line is colored (color-coded) to indicate the situation until the rear wheel of the host vehicle reaches the parallel position, so that the driver can quickly determine the degree of approach of the host vehicle to the parallel position. It becomes possible to grasp.

  In addition, since the backline display disappears when the rear wheel of the host vehicle reaches the parallel position, the driver can be surely notified that the host vehicle has reached the parallel position. After that, the vehicle can be moved backward in parallel along the white lines on the left and right of the parking frame.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the back line imitating the contour of the rear vehicle shape from the rear wheel of the vehicle is used, and the first area and the second area included in this back line are color-coded, but other than the back line These display elements may be used as a guide image.

  FIG. 5 is a diagram illustrating another example of the guidance image. In the example shown in FIG. 5, a bar-shaped guide image is included on the left side of the screen. This guidance image includes the first area b1 and the second area b2 as in the guidance image shown in FIG. 3, and the boundary position between the first area and the second area as the vehicle moves backward. When the rear wheel of the vehicle reaches the parallel position, the entire guide image becomes the first region.

  In the above-described embodiment, the guidance image is used. However, instead of or in parallel, guidance voice having the same presentation content may be used. For example, by shortening the period of intermittent sound as the rear wheel approaches the parallel position, and outputting a continuous sound when the rear wheel reaches the parallel position, the degree of approach of the host vehicle to the parallel position can be reduced. It is possible to present it to the driver in an easy-to-understand manner. As a result, the driver can quickly and accurately park the vehicle in the parking frame.

  As described above, according to the present invention, since the guide information is provided until the white line on the left and right of the parking frame reaches the position where the host vehicle is parallel (parallel position), the host vehicle moves backward to the parallel position. Even when the parallel position disappears from the road surface in the captured image when approaching, the driver can know how much the vehicle should be moved backward to reach the parallel position, and quickly and accurately It is possible to park in the parking frame.

DESCRIPTION OF SYMBOLS 1 Parking assistance apparatus 10 Back camera 12 Image memory 20 Parking frame extraction part 22 Steering angle detection part 24 Movement locus | trajectory estimation part 26 Parallel position specific | specification part 28 Parallel position loss | determination determination part 30 Movement distance calculation part 32 Movement locus drawing part 34 Backline drawing Unit 36 Rear image display processing unit 38 Display device

Claims (7)

Imaging means for imaging the rear of the host vehicle including the road surface;
A parking frame extraction means for extracting a parking frame included in a captured image obtained by imaging by the imaging means;
Steering angle detection means for detecting the steering angle of the host vehicle;
Based on the steering angle detected by the steering angle detection means, a movement trajectory prediction means for predicting the movement trajectory of the rear wheel when the host vehicle moves backward,
Parallel position specifying means for specifying a position of a rear wheel on the movement locus, the left and right white lines constituting the parking frame and the host vehicle being parallel to each other;
When the host vehicle retreats along the movement locus, the rear wheel is specified by the parallel position specifying means after the position specified by the parallel position specifying means disappears from the road surface included in the captured image. Guidance information presenting means for presenting guidance information up to the position;
The guide information presenting means includes a first moving distance that is a moving distance of the rear wheel from a time point when the position specified by the parallel position specifying means disappears from a road surface included in the captured image to a time point of interest. And presenting the guide information by drawing a guide image showing a ratio between the position of the rear wheel at the time of interest and a second movement distance that is a distance from the position of the rear wheel to the position specified by the parallel position specifying means. parking assist system and performing. In claim 1 ,
A movement locus drawing means for drawing the movement locus;
Rear image display processing for displaying the moving trajectory drawn by the moving trajectory drawing means and the guide image drawn by the guide information presenting means on the captured image obtained by imaging by the imaging means. Means,
The parking assistance device further comprising: In claim 1 or 2 ,
The guide image is a backline having a shape imitating a contour of a vehicle shape at the rear part from the rear wheel of the vehicle, and is a backline indicating a ratio between the first movement distance and the second movement distance. A parking assistance device characterized by the above. In any one of claims 1 to 3,
The guide image includes a first index having a length and a color corresponding to the first movement distance, and a second index having a length and a color corresponding to the second movement distance. A parking assistance device characterized by that. In any one of claims 1 to 4,
The parking assistance device according to claim 1, wherein the guidance information presenting means terminates the presentation of the guidance information when the rear wheel reaches the position specified by the parallel position specifying means. In any one of Claims 1-5 ,
The guidance information presenting means outputs the voice indicating that the rear wheel is approaching the position specified by the parallel position specifying means and that the rear wheel has reached this position, thereby providing the guidance information. A parking assistance device characterized by presenting information. A parking frame extraction step for extracting the parking frame included in the captured image obtained by imaging by the imaging means for imaging the rear of the host vehicle including the road surface by the parking frame extraction means;
A steering angle detection step of detecting the steering angle of the host vehicle by a steering angle detection means;
Based on the steering angle detected by the steering angle detection means, a movement trajectory prediction step for predicting the movement trajectory of the rear wheel when the host vehicle moves backward by the movement trajectory prediction means;
A parallel position specifying step for specifying a position of a rear wheel on the movement locus, wherein the left and right white lines constituting the parking frame and the host vehicle are parallel, by a parallel position specifying means;
When the host vehicle retreats along the movement locus, the rear wheel is specified by the parallel position specifying means after the position specified by the parallel position specifying means disappears from the road surface included in the captured image. A guide information presenting step for presenting guide information up to the position by the guide information presenting means;
Have a, the guide information presenting means, moving the first is a moving distance of the rear wheel to the point interest from the time the position identified lost from the road surface included in the captured image by the parallel position specifying means By drawing a guide image indicating the ratio of the distance and the second movement distance that is the distance from the position of the rear wheel at the time of interest to the position specified by the parallel position specifying means, A parking support method characterized by presenting .

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