JP4218441B2 - On-vehicle moving body detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle-mounted moving body detection apparatus that detects, for example, a pedestrian crossing the front of a vehicle using an image processing technique.
[0002]
[Prior art]
As one of the measures to prevent traffic accidents, a system that mounts a front obstacle detection sensor on a vehicle and applies an emergency brake when it is dangerous has been studied. As an example, a camera that captures the front of the vehicle is mounted on the vehicle, images obtained from this camera are sequentially stored, the latest image is compared with the previous image, and a difference is obtained, so that the shooting area is set for each pixel. Quaternization into four values of no object, object present, object retreat, and object approach, and a motion vector of the object is calculated based on pixel distributions corresponding to the object in the image, the object retreat, and the object approach, respectively. There is one that identifies a pedestrian on a pedestrian crossing by comparing the direction of the road and the direction crossing the road (for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-200906
[Problems to be solved by the invention]
However, in the apparatus described in Patent Document 1 described above, since image processing must be performed on the entire wide range of the image captured by the camera, a large amount of processing time is required for the detection processing of the moving object, There was a problem of poor recognition.
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to reduce the processing time of a captured image in a vehicle-mounted mobile body detection device that detects the presence or absence of a mobile body based on a captured image by a capturing unit. An object of the present invention is to provide a vehicle-mounted mobile body detection device that can perform the above-described operation.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention detects a form of a road in a shooting direction by a shooting unit from map data acquired by a map data acquisition unit, and processes a shot image for detecting the presence or absence of a moving object. Is narrowed to a range according to the form of the road with respect to one of the vertical, horizontal, and diagonal directions of the photographed image, and with respect to the oblique direction of the photographed image according to the photographing direction of the photographing means. , to run by narrowing the range corresponding to the vehicle speed.
Therefore, according to the present invention, it is not necessary to process the entire captured image, and the processing time can be shortened.
[0007]
In this case, in the present invention, when the image processing means detects the moving body can be provided with informing means and driving support means for notifying the presence of the moving object.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 2, a video camera 2 as a photographing unit is provided in the front portion of the roof 1 a of the vehicle 1. The video camera 2 uses, for example, a CCD element, and photographs the front direction, which is one direction around the vehicle 1, from the top of the vehicle 1.
[0009]
As shown in FIG. 1, an image photographed by the video camera 2 is sent to an image processing device 3 as image processing means. Although not shown, the image processing apparatus 3 includes a microcomputer, a memory, and the like. An image sent from the video camera 2 is obtained by pattern correlation between a road luminance pattern and a moving body luminance pattern such as a pedestrian or a vehicle. The image is binarized and the image binarized data is sequentially stored in a memory. Then, the image processing device 3 calculates the difference between the image binarization data of the latest frame and the already stored image binarization data, so that the imaging area has no object, there is an object, the object has retreated, and the object has entered. Based on the comparison between the direction of the movement vector and the transverse direction, the four values are converted into four values for each pixel, and the movement vector of the object is calculated from the distribution of the pixels corresponding to the object in the image, the object retreat, and the object approach. A person or other vehicle crossing the front of the vehicle 1 is identified (moving body detection process).
[0010]
When the image processing device 3 detects that the moving body crosses the front of the vehicle as described above, when the distance from the vehicle 1 is short, the image processing device 3 outputs a danger signal to the vehicle control device 4 as driving support means. The vehicle control device 4 receives the danger signal, and controls the brake device so that, for example, when the driver steps on the brake pedal, the driver is assisted and sudden braking is applied. The image processing device 3 calculates the distance from the vehicle 1 to the moving body by counting the number of pixels from the reference position for the captured image (distance calculation means). The reference position is set at the lower end of the photographed image shown in FIG. However, the reference position is not limited to the lower end of the captured image.
[0011]
The image processing device 3 receives a vehicle speed signal measured by a vehicle speed measuring device 5 as a speed detecting means of the vehicle 1. The vehicle speed measuring device 5 calculates the vehicle speed by, for example, counting a pulse signal per unit time that is output as the axle rotates from an axle rotation detection device (not shown). Further, map data ahead of the host vehicle 1 is input to the image processing device 4 from the navigation device 6.
[0012]
Here, the navigation device 6 includes a navigation control device 7, a map data storage device 8, a GPS receiver 9 as position detecting means, a speaker 10, a display device 11, an input device 12, and the like. The GPS receiver 9 receives a positioning signal from a GPS satellite and calculates the position of the vehicle 1. The control device 7 is mainly composed of a microcomputer, acquires map data around the vehicle 1 from the map data storage device 8 based on the position information acquired by the GPS receiver 9 and displays it on the display device 11.
[0013]
The map data storage device 8 comprises a DVD and its reader, and the map data stored on the DVD includes information such as the type of road and the position of a pedestrian crossing.
Moreover, the navigation apparatus 6 detects the advancing direction of the own vehicle 1 by comparing the position information received from the GPS receiver 9 with the previously received position information (vehicle advancing direction detecting means). Then, the navigation device 6 selects map data from the own vehicle 1 to the shooting range of at least the video camera 2 in the traveling direction from the map data around the own vehicle 1 acquired from the map data storage device 8, and the image processing device 3. Send to. In addition, you may comprise so that the image processing apparatus 3 may perform selection of the map data of the advancing direction of the own vehicle 1. FIG.
[0014]
When the destination is input by operating the input device 12, the control device 7 calculates a guide route from the current position to the destination, and displays the guide route in a color-coded manner on a map displayed on the display device 11. At the same time, the left / right turn direction is output from the speaker 10 by voice at an intersection or the like. Further, the speaker 10 issues a warning to the driver by voice or the like when it is detected that a moving body such as a pedestrian or another vehicle exists in front of the host vehicle as will be described later. The display device 11 functions not only as a map display unit but also as a notification unit of the image processing device 3. When the image processing device 3 detects a moving body, the moving body is detected by a signal from the image processing device 3. The position is notified by blinking display (warning display), for example.
[0015]
Now, the image processing device 3 narrows the range of the captured image to be processed based on the detection speed of the vehicle speed measurement device 8 and the map data from the navigation control device 7 during the moving body detection process. Yes. The contents of the moving object detection process will be described with reference to the flowcharts shown in FIGS.
[0016]
When the image processing apparatus 3 starts to execute the driving support program shown in FIG. 3, the moving object detection processing routine (step S1) is entered. This moving object detection processing routine is shown in FIG. When entering this routine, the image processing apparatus 3 first acquires a photographed image of the video camera 2 (step A1). Next, the image processing device 3 acquires the vehicle speed from the vehicle speed measuring device 5 (step A2), and calculates the image recognition vertical width from the vehicle speed (step A3). When this image recognition vertical width is set, as will be described later, the moving body detection process by the image processing device 3 does not cover the entire area of the image captured by the video camera 2, and the vertical, horizontal, and diagonal directions. Of these, the vertical direction (vertical direction in FIG. 7; the other direction intersecting with one direction in the present invention) is narrowed to the range of the vertical width of the image recognition.
[0017]
In this embodiment, the recognition vertical width is determined by the width (number of pixels) from the lower end (immediately before the vehicle 1) to the upper side (front of the vehicle 1), which is the reference position of the captured image. In the case of this embodiment, this recognition vertical width is determined as the vehicle travel distance from when the moving body is found to when the brake is operated until the vehicle stops. In step A3, the vehicle is actually based on the vehicle speed. The stop distance is calculated. For example, FIGS. 7A and 7B show the difference in the recognition vertical width W due to the difference in the vehicle speed. FIG. 7A shows the case where the vehicle speed is slow, and FIG. 7B shows the case where the vehicle speed is fast. Is shown.
[0018]
When the image processing device 3 performs the above recognition vertical width calculation processing, the navigation control device 7 acquires the position of the host vehicle 1 (step A4) and acquires map data in front of the host vehicle 1 to obtain an image. The data is sent to the processing device 3 (step A5). Then, the image processing device 3 uses the position of the host vehicle 1 and the map data sent from the navigation control device 7 in the captured image of the video camera 2 in front of the host vehicle 1 as shown in FIGS. ) And (c) (step A6), whether there are junction points such as (d), (e), and (f) (step A7). It is determined whether there is a pedestrian crossing as shown in (g) (steps A8 , A9 ), and then a lateral recognition position determination process is executed (steps A10- A13 ).
[0019]
The horizontal direction recognition position determination processing in steps A10 to A13 is for setting the processing target range of the captured image for detecting the presence or absence of the moving body in the horizontal direction (other direction). Is shown in That is, when entering the lateral recognition position determination processing routine, the image processing apparatus 3 has a special road form such as an intersection, a junction, and a pedestrian crossing obtained from the map data, and how many meters away from the own vehicle 1. It calculates where in the captured image it corresponds (step B1). Then, it is determined whether the special road form is not included in the photographed image or is within the recognition vertical width. If it is not included (“NO” in step B2), the image processing apparatus 3 detects the moving object. The routine of FIG. 4 is terminated without performing the process, and the process proceeds to step S2 of FIG.
[0020]
When the special road form is within the recognized vertical width in the photographed image (“YES” in step B2), the image processing device 3 determines the position of the special road form in the photographed image, and performs image horizontal direction recognition position setting processing. Perform (Step B3). For example, when the intersection A exists as shown in FIG. 6, this recognition position is set to a range that is equal in width D to the left and right around the side edge E of the center road in the vertical direction within the vertical width W. Is done. In this case, the width D is appropriately determined depending on the road form such as the width of the road. Further, only the width F is removed from the central portion of the traveling road. The reason why the center portion of the traveling road is excluded from the image processing target by the width F is that the driver concentrates attention, but it is not particularly necessary to remove it.
[0021]
As described above, in the image horizontal direction recognition position determination processing in steps A10 to A13, the horizontal direction recognition position (width) is determined according to each road form. In addition, the broken line shown to Fig.8 (a)-(g) shows the image horizontal direction recognition position (range) in each road form. If “NO” is determined in step B2 of FIG. 5, the horizontal direction recognition position is 0 (zero), which means that image processing is not performed.
[0022]
When the image horizontal direction recognition position determination process in steps A10 to 13 is finished, the image processing apparatus 3 thereafter executes the above-described moving body detection process (step B14), and proceeds to step S2 in FIG. Then, when the moving object does not exist (“NO” in step S2), the image processing device 3 returns to the original step S1. If there is a moving object (“YES” in step S2), the image processing device 3 performs a notification process and a driving support process, and returns to step S1. Here, the notification process is performed by displaying the position of the moving object on the map of the display device 11 and by emitting sound from the speaker 10. The driving support process outputs a danger signal to the vehicle control device 4 so that when the brake operation is performed, the vehicle control device 4 controls the brake device so that the brake is suddenly applied. It may be to sound a buzzer.
[0023]
Thus, according to the present embodiment, since the image processing range in the lateral direction (one direction referred to in the present invention) for detecting the presence or absence of the moving body is narrowed according to the form of the road, the presence or absence of the moving body. The recognition process for detecting can be performed quickly.
Particularly in this embodiment, since the image processing range is narrowed in the vertical direction according to the vehicle speed, the recognition process can be performed more rapidly.
[0024]
The present invention is not limited to the embodiments described above and shown in the drawings, and can be expanded or changed as follows.
The present invention can be widely applied not only to photographing the front with a video camera in order to ensure safety in front of the vehicle, but also to photographing one direction around the vehicle. For example, you may make it image | photograph the diagonally back of the vehicle used as the blind spot of a rear-view mirror or a fender mirror. In this case, the image processing is executed with the lateral width of the captured image narrowed according to the vehicle speed. Further, depending on the shooting direction, image processing may be performed by narrowing the width of the captured image in the diagonal direction (oblique direction) according to the vehicle speed.
The map data around the host vehicle may be acquired via a wireless communication network by connecting to a map database server (map center) by wireless communication means.
The position of the host vehicle is not limited to the GPS receiver, and may be acquired by a combination of a geomagnetic direction sensor, a vehicle travel distance sensor, and the like.
Means may be provided for notifying the image processing device 3 of the response operation to the alarm. For example, when the accelerator pedal is loosened to reduce the vehicle speed, the image processing device 3 may detect this and stop the alarm.
The width of the traveling road may be predicted from the width of the host vehicle, and the image processing range may be changed accordingly.
The shooting range may be changed by changing the vertical tilt of the video camera 2 in accordance with the vehicle speed.
In the residential area from the map data, there are many people jumping out of the house, so the image processing range may be limited to the entrance of the house.
The traveling direction of the vehicle may be detected by a gyroscope.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing a shooting range of a vehicle video camera. FIG. 3 is a flowchart for driving support. FIG. 4 is a flowchart for detecting a moving object. FIG. 5 is a flowchart for setting a horizontal processing range of a captured image. FIG. 6 is a diagram illustrating an example of a map displayed on a display device. FIG. 7 is a diagram illustrating an example of a captured image by a video camera. ] Figure showing various road forms 【Explanation of symbols】
1 is a vehicle, 2 is a video camera (photographing means), 3 is an image processing device (image processing means), 4 is a vehicle control device (driving support means), 5 is a vehicle speed measuring device (vehicle speed detecting means), and 7 is navigation control. An apparatus (map data acquisition means), 9 is a GPS receiver (position acquisition means), 10 is a speaker (notification means), and 11 is a display device (notification means).

Claims (3)

A photographing means mounted on the vehicle and photographing one set direction around the own vehicle;
Image processing means for detecting the presence or absence of a moving object by processing a photographed image by the photographing means;
Position acquisition means for acquiring the position of the host vehicle;
Map data acquisition means for acquiring map data of at least the imaging direction of the imaging means in the vicinity of the detection position by the position acquisition means;
Speed detecting means for detecting the speed of the host vehicle,
The image processing means detects the form of the road in the shooting direction by the shooting means from the map data acquired by the map data acquisition means, and performs processing of the shot image for detecting the presence or absence of a moving body. For one of the vertical, horizontal, and diagonal directions of the image, narrow the range according to the form of the road, and according to the shooting direction of the shooting means, with respect to the diagonal direction of the shot image, A vehicle-mounted moving body detection apparatus, which is executed by being narrowed to a range corresponding to the vehicle speed detected by the speed detection means. The in-vehicle moving body detection apparatus according to claim 1, further comprising an informing means for informing the presence of the moving body when the image processing means detects the moving body. When the image processing means detects the presence of a moving body, vehicle moving object detection apparatus according to claim 1 or 2, characterized in that it comprises a driving support means for supporting the operation of the vehicle.

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