JP2009205360A - Vehicle obstacle detection device and vehicle obstacle detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase accuracy of detecting an obstacle which becomes an obstacle to vehicle traveling including a road shape at the side part of a vehicle. <P>SOLUTION: A vehicle obstacle detection device is provided with: a light beam irradiating means 11 for irradiating an obstacle present beside the vehicle with a light beam for obstacle detection with prescribed length from the side edge of a vehicle; a photographing means 12 for photographing a prescribed range including the light beam for obstacle detection emitted from the light beam irradiating means 11; and an image processing means 13 for detecting the state change in the light beam for obstacle detection to be acquired by tracing the light beam for obstacle detection photographed by the photographing means 12. Then, an obstacle present beside the vehicle is detected based on the detection result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle obstacle detection device and a vehicle obstacle detection method for detecting obstacles such as grooves and curbs on the side of a vehicle.

Conventionally, as this type of technique, for example, a technique using an image processing technique such as pattern matching is known. An example of a method for detecting road shapes and obstacles using this image processing technique is to use the parallax of the foreground image of a vehicle photographed by two cameras installed at the same height and at constant intervals in the horizontal direction. A so-called stereo camera technique is known that calculates the distance to an object reflected in each region of an image by triangulation. As a system for detecting the road shape and the position of an obstacle in front of the vehicle using such a technique and presenting to the driver whether or not the vehicle is allowed to pass based on the detection result, it is described in the following documents, for example Is known (see Patent Document 1).
JP-A-9-128687

  In the conventional method of detecting obstacles that obstruct the running of a vehicle using image processing technology, it is a target to be detected by using a temporal difference of captured images or by limiting the detection area or detection direction. Accordingly, various processing methods have been proposed. In any of the methods, detection processing is performed based on information on the color, luminance, brightness, or the difference between the pixels in the captured image. For this reason, for example, when the corner of the detection target is round, depending on how the light hits, changes in luminance and brightness of the surrounding pixels are reduced, and the contour of the object cannot be detected, and as an obstacle There was a risk that it could not be recognized.

  Therefore, the present invention has been made in view of the above, and an object of the present invention is to detect vehicle obstacles with improved detection accuracy of obstacles that hinder vehicle travel including road shapes on the side of the vehicle. An apparatus and a vehicle obstacle detection method are provided.

  In order to achieve the above object, means for solving the problems of the present invention are: irradiation means for irradiating an obstacle detection light beam having a predetermined length from the vehicle side end toward the vehicle side; and irradiation from the irradiation means. An image capturing unit that captures a predetermined range including an obstacle detection light beam, and a vehicle lateral direction based on a state change of the obstacle detection light beam obtained by tracing the obstacle detection light image captured by the image capturing unit. And detecting means for detecting the obstacle.

  ADVANTAGE OF THE INVENTION According to this invention, the precision which detects obstructions, such as a groove | channel on the vehicle body side and a curbstone, can be improved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment for carrying out the present invention will be described below with reference to the drawings.

  1 is a diagram illustrating a configuration of a vehicle obstacle detection device according to a first embodiment of the present invention. The detection apparatus according to the first embodiment illustrated in FIG. 1 includes a light beam irradiation unit 11, a photographing unit 12, an image processing unit 13, a control unit 14, and a display unit 15.

  The light beam irradiation means 11 is a light beam for detecting an obstacle with a specific wavelength set in advance as a light beam for detecting an obstacle that obstructs the running of the vehicle including a road shape such as a groove (side groove) on the side of the vehicle or a curb. To the side of the vehicle. For example, visible light such as near-infrared light or red laser light can be used as the obstacle detection light beam. For example, an existing CCD camera is used as the photographing means 12 for photographing the irradiated obstacle detection light beam. In this case, near infrared rays that are relatively compatible with the CCD camera are suitable.

  For example, when detecting an obstacle on the side of the left front wheel of the vehicle, the light beam irradiation means 11 starts from a ground contact position on the outer side of the front wheel that is surely on the same plane as the vehicle body, as shown in FIG. Then, an obstacle detection light beam having a predetermined distance, for example, a length of about 1.5 m, is irradiated in a direction perpendicular to the vehicle center line. In the case of such irradiation, for example, as shown in FIG. 3, the light irradiation means 11 installs a light emitting element constituting the light irradiation means 11 inside the door mirror 31, and detects an obstacle on the lower front side of the door mirror 31. This is realized by providing a slit 32 serving as a light beam irradiation port. As a light irradiation method, a light source such as a light emitting diode may be used to irradiate a predetermined length at a time, or a high speed so that light is irradiated to a predetermined length like a scanning radar. The light emitting element may be scanned with.

  In the case of detecting an obstacle on the side of the right front wheel of the vehicle, it is possible to install the light beam irradiation means 11 on the door mirror 31 on the right side of the vehicle and irradiate the obstacle detection light beam in the same manner as above. Even in the case of detecting an obstacle on the side of the left and right rear wheels, by installing the light beam irradiation means 11 on the rear side of the door mirror 31 and irradiating the obstacle detection light beam in the same manner as described above. Is possible.

  The imaging unit 12 is composed of an in-vehicle camera 33 that can detect and capture the obstacle detection light beam having the wavelength irradiated by the light beam irradiation unit 11, and has a predetermined range including the irradiation range of the obstacle detection light beam. As shown in FIG. 3, for example, as shown in FIG. 3, the door mirror 31 is installed in the same manner as the camera mounting position employed in the side blind monitor system that monitors the side of the vehicle based on the image of the side of the vehicle. A vehicle-mounted camera 33 is installed below the.

  It is desirable that the camera 33 be installed at a position that is not collinear with the light source of the obstacle detection light beam. If the lens center of the camera 33 and the light source of the obstacle detection light beam are on the same line, as shown in FIG. 4, if there is a three-dimensional object on the line in the irradiation direction of the obstacle detection light beam, This is because the position of the light beam on the image does not change, and the obstacle cannot be detected.

  The image processing unit 13 determines the distance to the obstacle on the side of the vehicle based on a change in the state of at least one light beam such as the color, brightness, and brightness of the obstacle detection light beam in the image captured by the image capturing unit 12. The process which detects is performed. Specific processing contents will be described with reference to a flowchart showing a processing procedure of FIG. 5 described later.

  The control unit 14 has a function of controlling the irradiation operation of the obstacle detection light beam in the light beam irradiation unit 11, the photographing operation in the photographing unit 12, and the display operation in the display unit 15, and is photographed by the photographing unit 12 on the display unit 15. Control when displaying an image, on / off control of irradiation of the obstacle detection light beam in the light beam irradiation means 11, movement of the light source of the obstacle detection light beam, and scanning of the obstacle detection light beam Control.

  The control unit 14 displays the display unit when the distance to the obstacle detected by the image processing unit 13 is a predetermined distance, for example, about 50 cm or less, or when the operation switch (camera switch) of the photographing unit 12 is turned on. 15 displays an image.

  Note that the image processing unit 13 may be integrated with the control unit 14 and configured as an in-vehicle camera controller that performs overall control of the operation of the camera 33 constituting the photographing unit 12.

  The display means 15 is composed of, for example, a liquid crystal monitor used in a vehicle-mounted navigation device, and images taken by the photographing means 12, for example, a distance to an obstacle or a distance to an obstacle are close to each other. Present information about obstacle detection results such as alerts to the driver.

  Next, the procedure of the obstacle detection process will be described with reference to the flowchart of FIG. 5 showing the detection procedure. This detection procedure is repeatedly executed at predetermined time intervals set in advance.

  In FIG. 5, first, a position (initial position) for starting tracing (analysis) of the obstacle detection light beam on the image taken by the on-vehicle camera 33 is set. The obstacle detection light beam is irradiated from the ground contact position on the outside of the front wheel, and the position where the ground contact position on the wheel exterior on the image captured by the in-vehicle camera 33 is always constant as shown in FIG. (Sx, Sy) is the trace start position of the obstacle detection light beam (step S501).

  Next, as shown in FIG. 2, the trace is advanced in the horizontal direction from the trace start position (Sx, Sy) to the position (Ex, Sy) at the vehicle outer end of the obstacle detection light beam. In the example shown in FIG. 2, tracing is advanced in the left direction because the image is on the left side of the vehicle body. In addition, in order to absorb the blur of the obstacle detection light beam due to vibration during traveling, the trace target range may be expanded by Δy, for example, about 2 to 3 pixels in the vertical direction as shown in FIG.

  In this way, after the tracing of the obstacle detection light beam is started, the state of at least one of the color, luminance, and brightness of the pixel of the current trace coordinate (Tx (Sx ≦ Tx ≦ Ex), Sy) is determined. It is determined whether or not the obstacle detection light beam is substantially the same (step S502).

  If the result of determination is the same, after moving the trace position to the left by one pixel (step S503), the determination processing shown in the previous step S502 is performed, and the above determination processing is performed until the trace position Tx reaches the vehicle outer end position Ex. Are repeatedly executed (steps S502 to S504).

  In the discrimination processing shown in step S502, when at least one of the color, brightness, and brightness of the pixel of the trace coordinates (Tx, Sy) is different from that of the obstacle detection light beam, the obstacle detection light beam at this position. Is calculated as the distance L from the vehicle to the obstacle (step S505).

  Here, FIG. 6A and FIG. 7A each show an example of a captured image of the obstacle detection light beam when there is, for example, a side groove 61 or a curbstone 71 as an obstacle that obstructs vehicle travel on the side of the vehicle. The coordinate relationship is shown in FIGS. 6B and 7B.

  When the side groove 61 is present, the obstacle detection light beam is as shown in FIG. 6, and the obstacle detection light beam is shifted to the lower side of the trace target range and interrupted in the lateral direction. Therefore, the length L from the trace start position to the interrupted position is calculated as the distance to the end of the side groove 61.

  On the other hand, when there is a curb 71, it becomes as shown in FIG. 7, and the obstacle detection light beam has a step on the upper side of the trace target range and is shifted upward and interrupted. Therefore, the length L to the position shifted from the trace start position is calculated as the distance to the end of the curb 71.

  Next, a procedure of processing for detecting the height of an obstacle on the side of the vehicle will be described with reference to the flowchart of FIG.

  When there is an obstacle such as a wall 91 on the side of the vehicle, the direction (light trace) of the obstacle detection light beam irradiated on the wall 91 is obliquely upper left from the position where the wall 91 is located as shown in FIG. Bend to. Note that the maximum value of the height that can be detected is the difference between the length (Sx−Ex) of the obstacle detection light beam and the distance L to the obstacle.

  First, the processes shown in steps S801 to S805 are the same as the processes shown in steps S501 to S505 of FIG.

  Next, as shown in FIG. 9, the direction of tracing from the coordinate (Hx) determined to have been interrupted to the left of the obstacle detection light beam in step S802 is changed upward in the order of the left side and the left side in the order of the left side. Advance and trace to the top of the obstacle detection beam. In order to deal with an obstacle standing diagonally, the trace target range may be expanded by Δx, for example, about 2 to 3 pixels in the horizontal direction as shown in FIG.

  First, after the coordinates to be traced are advanced by one pixel upward (step S806), at least one of the color, brightness, or brightness of the pixel at the trace coordinates (Tx, Ty = Sy) before the advance is an obstacle detection light beam. It is discriminated whether or not it is almost the same as the one (step S807). If the two are different as a result of the determination, the trace coordinate is advanced to the left by one pixel (step S808), and the above step S807 is performed until it is determined that the x coordinate of the trace coordinate has reached the end coordinate Ex of the obstacle detection light beam. , S808 is repeatedly executed to continue tracing (step S809).

  On the other hand, if both are the same as a result of the determination in the previous step S807, the coordinates (Rx, Ry) where the obstacle detection light beam is detected are set to the current trace coordinates (Tx, Ty) (step S810), Until it is determined that the y coordinate of the trace coordinates has reached the coordinate Ey at the upper end of the image, the processes in steps S806, S807, and S810 are repeatedly executed to continue the trace (step S811).

  After repeatedly executing such processing, when the y coordinate of the current trace coordinate reaches the y coordinate Ey at the upper end of the image, as shown in FIG. 9, the coordinates (Rx, Ry) that finally detect the obstacle detection light beam are detected. ) To the vanishing point 92 of the wall 91 and the intersection 94 (Hx, Hy) of the perpendicular drawn upward from the position (Hx) where the tracing of the obstacle detection light beam is interrupted, and (Hy−Sy) is obtained. The height H of the obstacle is calculated (step S812).

  As described above, in the first embodiment, the influence of the shape and pattern of the obstacle, the brightness of the surroundings, and the like can be obtained by a simple process of tracing the irradiated obstacle detection light beam and detecting the state change of the light beam. The distance to obstacles such as grooves and curbs on the side of the vehicle body can be detected.

  In addition, when the obstacle detection light beam in the photographed image is interrupted and its state changes, the direction in which the obstacle detection light beam is traced upward is the obstacle detection light beam obtained by tracing upward. Based on this, by detecting the height to the obstacle on the side of the vehicle, in the case of a three-dimensional obstacle, it becomes possible to detect the height of the obstacle in addition to the distance to the obstacle.

  In addition, it is possible to detect an obstacle in the vicinity of the vehicle body in parking, width adjustment, passing through a narrow road, etc., to recognize the approach situation, and to present the approach situation to the driver by voice or image.

  Furthermore, it becomes possible to detect an obstacle outside the angle of view covered by the ultrasonic sensor or the laser sensor, such as a side groove or a curb with a low height.

  Next, a second embodiment of the present invention will be described. The feature of the second embodiment is that the irradiation position of the obstacle detection light beam is set in front of the first embodiment, and the rest is the same as the first embodiment. That is, as shown in FIG. 10, the irradiation position of the obstacle detection light beam moves forward by a predetermined distance FP, for example, about 1 m from the front end of the front bumper, in parallel with the vehicle center line, with the ground contact position outside the front wheel as a base point. An obstacle on the front side is detected.

  Thus, when the irradiation position of the obstacle detection light beam is set to the front, the position at which the obstacle detection light beam is displayed on the captured image is such that the inclination of the road surface is the inclination of the vehicle pitch direction and the roll direction. In the same case, it is always constant as shown in FIG. Therefore, the coordinates of the trace start position and the end position of the obstacle detection light beam are the right end (Sx2, Sy2) and the left end when the obstacle detection light beam is irradiated on the same plane in the vehicle pitch direction and the roll direction. (Ex2, Sy2) (when an obstacle on the left side is detected). The processing content of obstacle detection on the left side between these two coordinates is the same as the procedure shown in the flowchart of FIG.

  Further, by setting the irradiation position of the obstacle detection light beam to the front of the vehicle, the camera 33 is installed below the light source of the light beam irradiation means 11, and the wall surface 121 is on the left front side as shown in FIG. In this case, as shown in FIG. 13, a straight line L1 connecting the irradiation position of the obstacle detection light beam on the wall surface 121 and the installation position of the camera 33 is a straight line connecting the irradiation position of the road surface and the installation position of the camera 33. Above L2. Thereby, the display position of the obstacle detection light beam on the photographed image is above the irradiation position on the road surface, and by using this relationship, the presence or absence of a three-dimensional object such as the wall surface 121 in front of the vehicle can be detected. it can.

  Next, with reference to the flowchart of FIG. 14, the procedure of the detection process of the solid object ahead of a vehicle is demonstrated.

  First, a series of processes shown in steps S1401 to S1405 are executed. This series of processes is the same as the processes in steps S501 to S505 shown in FIG.

  Next, when the obstacle detection light beam is not detected on the irradiation position (Sy2, Sx2 to Ex2) on the road surface, the obstacle detection light beam is traced while moving the y coordinate of the trace coordinate to the upper side of the image. To do.

  That is, after executing the processing in step S1405, the y coordinate to be traced is moved upward by one pixel (step S1406), and it is determined whether or not the y coordinate Ymax at the upper end of the image has been reached (step S1407). If not, it is determined whether or not at least one of the color, brightness, and brightness of the pixel of the current trace coordinate is substantially the same as that of the obstacle detection light beam (step S1408).

  If they are different as a result of the determination, the processes in steps S1406 to S1408 are repeated until the y coordinate to be traced reaches Ymax. On the other hand, if both are the same as a result of the discrimination, the obstacle detection light beam that has moved upward as shown in FIG. 12 is detected, so it is estimated that there is a three-dimensional object ahead (step S1409). A series of detection processing ends.

  In the second embodiment, the case where the obstacle detection light beam is irradiated to the front of the vehicle is described. However, the light source is installed or movable so that the obstacle detection light beam can be irradiated to the rear in addition to the front. In addition, when the in-vehicle camera 33 is configured with a wide-angle camera and the rear of the vehicle is included in the shooting range in addition to the front of the vehicle, for example, the obstacle detection light beam is irradiated to the rear side of the vehicle when reversing or turning right In addition, it is possible to detect obstacles behind the vehicle and detect entrainment when turning right or left.

  As described above, in the second embodiment, by moving the irradiation position of the obstacle detection light beam forward or backward, obstacles such as side grooves, curbs, and walls in the front or rear of the vehicle can be detected.

  FIG. 15 is a diagram illustrating the configuration of the vehicle obstacle detection device according to the third embodiment of the present invention. The detection apparatus of the third embodiment shown in FIG. 15 is provided with a light beam irradiation means 151 that can change the irradiation state in place of the light beam irradiation means 11 employed in the first and second embodiments, and is further adopted in the first embodiment shown in FIG. In addition to the above-described configuration, the illuminance detection unit 152 and the irradiation control unit 153 are provided, and are performed in addition to the operations described in the first and second embodiments.

  As described in the first and second embodiments, the light beam irradiation means 151 irradiates a linear (slit-shaped) light beam (slit irradiation) from the slit-shaped irradiation port when detecting an obstacle. In addition, by switching the shape of the light source or the shape of the irradiation port, the entire shooting range shot by the shooting unit 12 is irradiated (entire irradiation) to brighten the shot image.

  The illuminance detection means 152 is composed of, for example, an illuminance sensor using a photodiode used for an autolight that senses brightness and automatically turns the headlamp on / off. The illuminance at the time of determining is detected.

  The irradiation control unit 153 determines whether the headlamp is on or off based on the illuminance detected by the illuminance detection unit 152. The on / off state of the headlamp may be determined by detecting the on / off state of the on / off switch of the headlamp. In this case, the illuminance detection means 152 is not necessary.

  The irradiation control unit 153 switches the irradiation state (slit irradiation / entire irradiation) of the light beam irradiation unit 151 in accordance with the display / non-display of the display unit 15 by the control unit 14.

  The illuminance detection unit 152 and the irradiation control unit 153 may be integrated by being included in the function of the in-vehicle camera controller touched earlier.

  Next, the irradiation state switching control in the light beam irradiation means 151 will be described with reference to the flowchart shown in FIG.

  In FIG. 16, first, it is determined whether or not an image photographed by the photographing means 12 is displayed on the display means 15 (step S1601). If it is not displayed as a result of the determination, the light beam irradiation means 151 irradiates the obstacle detection light beam (step S1602).

  on the other hand. If it is displayed as a result of the determination, it is subsequently determined whether or not the headlamp is lit based on the illuminance detected by the illuminance detection means 152 (step S1603). If the headlamp is turned on as a result of the determination, the entire imaging range is irradiated by the light beam irradiation means 151 in order to brighten the imaging range (step S1604). On the other hand, when the headlamp is not turned on, the irradiation of the obstacle detection light beam is stopped (step S1605), and the extra light beam is not reflected in the photographed image so that it is easy to see. At this time, a function for irradiating a guideline display light beam indicating the approach limit to the detected obstacle is added to the light beam irradiation means 151, and a guideline display light beam is irradiated instead of the obstacle detection light beam. The driver may be alerted via 15 images.

  As described above, in the third embodiment, when the display unit 15 is displaying a captured image, the visible light is used as the obstacle detection light beam by stopping the irradiation of the obstacle detection light beam. Even in such a case, an extra obstacle detection light beam that is not related to the surrounding environment in which the image was taken is not displayed, so that the displayed image can be easily viewed.

  Further, by irradiating the guideline display light beam and projecting the guideline display light beam on the display means 15, the driver can be informed of the approaching state of the vehicle to the obstacle, and the driver can be alerted.

  When the headlight of the vehicle is lit, the illumination means illuminates the photographing range photographed by the photographing means 12, so that even when the photographing range is dark, it is possible to photograph in the illuminated state. This makes it possible to make the displayed captured image easy to see.

It is a figure which shows the structure of the vehicle obstruction detection apparatus which concerns on Example 1 of this invention. It is a figure which shows how the light ray for an obstacle detection in a picked-up image is reflected. It is a figure which shows the installation position of a vehicle-mounted camera and a slit. It is a figure which shows the irradiation direction and imaging | photography range of an obstruction detection light beam. 3 is a flowchart illustrating a procedure for detecting a distance to an obstacle according to the first embodiment. It is a figure which shows the example of a detection of the side groove | channel as an obstruction. It is a figure which shows the example of detection of the curb as an obstruction. 3 is a flowchart illustrating a procedure for detecting the height of an obstacle according to the first embodiment. It is a figure which shows the example of a detection of the side wall surface as an obstruction. It is a figure which shows the irradiation direction of the light beam for an obstacle detection. It is a figure which shows how the obstacle detection light beam is reflected in the picked-up image when the light beam for obstacle detection is irradiated in the irradiation direction shown in FIG. It is a figure which shows the example of a detection of the front wall surface as an obstruction. It is a figure which shows the mode of the irradiation position of the obstacle detection light ray in the detection example shown in FIG. 12 is a flowchart illustrating a procedure for detecting an obstacle according to the second embodiment. It is a figure which shows the structure of the vehicle obstruction detection apparatus which concerns on Example 3 of this invention. 10 is a flowchart illustrating an operation procedure according to the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11,151 ... Light irradiation means 12 ... Imaging means 13 ... Image processing means 14 ... Control means 15 ... Display means 31 ... Door mirror 32 ... Slit 33 ... Camera 61 ... Side groove 71 ... Curb 91 ... Wall 92 ... Vanishing point 93 ... Straight line 94 ... Intersection 121 ... Wall surface 152 ... Illuminance detection means 153 ... Irradiation control means

Claims (7)

Irradiating means for irradiating the vehicle side with a predetermined length of obstacle detection light beam from the vehicle side end;
Imaging means for imaging a predetermined range including the obstacle detection light beam emitted from the irradiation means;
Vehicle having an obstacle on the side of the vehicle based on a change in state of the obstacle detection light beam obtained by tracing the obstacle detection light beam photographed by the photographing means; Obstacle detection device. When the state of the obstacle detection light beam in the captured image changes, the detection means sets the direction in which the obstacle detection light beam is traced upward, and the state of the obstacle detection light beam obtained by tracing upward The vehicle obstacle detection device according to claim 1, wherein a height to an obstacle on the side of the vehicle is detected based on the change. 3. The vehicle obstacle detection according to claim 1, wherein the irradiation unit moves the irradiation position of the obstacle detection light beam toward the front side or the rear side of the vehicle from the ground point between the front wheel and the road surface. 4. apparatus. Comprising display means for displaying an image photographed by the photographing means;
The said light irradiation means stops irradiation of the light for obstacle detection, when the said display means is displaying the image | photographed image, The any one of Claim 1, 2, and 3 characterized by the above-mentioned. Vehicle obstacle detection device. The light beam irradiation unit irradiates a guideline display beam of visible light that urges an approach to the detected obstacle between the detected obstacle and the side of the vehicle. Vehicle obstacle detection device. When the headlamp of the vehicle is lit when displaying the image photographed by the photographing means on the display means, the light beam irradiating means illuminates the photographing range photographed by the photographing means. The vehicle obstacle detection device according to claim 4 or 5, wherein irradiation is performed.   The obstacle detection beam of a predetermined length is irradiated from the vehicle side end to the side of the vehicle, a predetermined range including the irradiated obstacle detection beam is photographed, and the captured obstacle detection beam is traced. A vehicle obstacle detection method comprising: detecting an obstacle on the side of the vehicle based on a change in the state of the obstacle detection light beam obtained in this way.

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