JP3077529B2 - Obstacle warning device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically measuring a distance between a host vehicle and an object around the host vehicle and determining a position of a peripheral object that is dangerous when the host vehicle continues to run. The present invention relates to a vehicle obstacle alarm device that detects and issues an alarm.

[0002]

2. Description of the Related Art When changing lanes while a vehicle is running, a driver checks the rear view using a rearview mirror or a side mirror. At this time, it is necessary to shift the line of sight. There was a problem with checking the rear while driving. Therefore, in order to automatically detect a rear side obstacle, as described in Japanese Utility Model Laid-Open No. Sho 62-189679, when an echo is detected from a predetermined distance and direction by a radar device, the obstacle is detected. There is known a configuration in which it is assumed that the vehicle is approaching and a warning is issued. Further, in the specification and drawings of Japanese Patent Application No. 5-186971 by the present applicant, the relative speed with respect to the other vehicle on the rear side is obtained based on the output of the position sensor, and the presence or absence of safety in lane change is detected. A rear side monitoring device that issues an alarm when needed is disclosed. The position sensor used here uses two video cameras, measures the distance to other vehicles based on the distance between the two video cameras, the amount of image shift of each camera, and the focal length of the video camera. The angle to the other vehicle is obtained from the number of the divided window, and the position of the other vehicle can be detected.

In this case, in particular, as shown in FIG. 12, a plurality of distance measurement windows w1 to w9 are set at the center of the image as shown in FIG. Are obtained, and distance measurement information is obtained. As a result, the object to be measured can be clarified, the accuracy of distance measurement can be improved, and the window in which the object to be measured is located can be obtained, and the direction of the object to be measured can be calculated. As described above, when the conventional rear side monitoring device is used, it is possible to automatically detect the distance to another vehicle on the rear side and to issue an alarm when the lane change is dangerous based on the data. .

[0004]

However, Japanese Utility Model Application Laid-open No. Sho 62-189679 and Japanese Patent Application No. 5-1 have been disclosed.
It is assumed that the conventional rear side monitoring device disclosed in the specification and the drawing of No. 86971 is used, and this is applied to right and left turns. In this case, in particular, in the case of observing the vehicle diagonally behind or ahead, the dangerous distance greatly differs depending on the angle of the detection direction. That is, if the approaching vehicle is near the own vehicle, that is, in the same driving lane as the own vehicle, or near the own vehicle driving lane in the adjacent lane and is located behind the own vehicle, the entrainment collision timing associated with the right or left turn will be the adjacent lane. Faster than the traveling vehicle.

[0005] Therefore, when the warning distance is set to be constant, a warning is issued appropriately to an approaching vehicle traveling in an adjacent traveling lane at a limited angle, and an approaching vehicle traveling in other traveling areas is appropriately issued. On the other hand, there is a high possibility that the warning will be lost soon, which has been a problem. In particular, this tendency was remarkable in the case of approaching motorcycles. It is an object of the present invention to provide a vehicle obstacle warning device that can reliably prevent an approaching vehicle from being involved in a collision when changing lanes.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the invention according to claim 1 is obtained from a pair of cameras provided for photographing obliquely forward or obliquely rearward of a vehicle and each camera. From each of the images, an image of a portion corresponding to a detection area in which a plurality of windows are formed side by side in the width direction of the same image is extracted for each of the windows, and a shift amount of the image is detected for each of the windows. Distance measurement processing means for measuring the distance to the obstacle for each window based on the deviation amount, and relative speed detection means for detecting a relative speed based on a change in the distance to the obstacle detected by the distance measurement processing means A vehicle speed detecting means for detecting a vehicle speed, an alarm means for warning the presence of an obstacle, and a distance between the obstacle detected by the distance measurement processing means is smaller than a warning distance determined by the vehicle speed and the relative vehicle speed. When is characterized in that a warning control means for operating said alarm means.

According to a second aspect of the present invention, in the vehicle obstacle alarm device according to the first aspect, the alarm control means sets a distance from the obstacle detected by the distance measurement processing means for each window. A configuration is such that a window located closer to the host vehicle in the width direction of the entire image is compared with a larger threshold value, and the guard distance is determined to be larger when the detection distance is smaller than the threshold value than when the detection distance is larger than the threshold value. It is characterized by having been done. According to a third aspect of the present invention, in the vehicle obstacle warning device according to the first aspect, the vehicle further includes a lane operation detecting unit that detects a lane change operation of an occupant, wherein the alarm unit detects the lane change operation. When the detected distance is smaller than the caution distance, the warning means is activated.

According to a fourth aspect of the present invention, in the vehicle obstacle warning device according to the first aspect, the distance measurement processing means has a window located on a side closer to the own vehicle in the width direction of the entire image. The detection area is set by sequentially arranging the plurality of windows so as to be located higher in the height direction of the entire image than the window located on the far side of the image.

[0009]

According to the first aspect of the present invention, an image of a detection area in which a plurality of windows are formed side by side is extracted by a distance measurement processing means from all the images obliquely forward or obliquely rearward of the vehicle. The amount of displacement of the image of the camera is detected, the distance to the obstacle is measured based on the amount of displacement, the relative speed detection means detects the relative speed based on the change in the distance to the obstacle, and the alarm control means When the distance to the object is smaller than the warning distance determined by the vehicle speed and the relative vehicle speed, the warning means is activated. According to a second aspect of the present invention, the alarm control means of the vehicle obstacle alarm device according to the first aspect is configured such that a distance from the obstacle is set for each window, and the distance to the own vehicle in the width direction of the entire image is set. The closer the window is, the greater the threshold value is set. If the detection distance is short, the warning distance is determined to be larger than the case where the detection distance is large. ) Can be distinguished for each approaching vehicle and the alerting means can be driven by changing the alerting distance, and an alarm can be activated early for approaching vehicles traveling on the near side.

According to a third aspect of the present invention, when the alarm means of the vehicle obstacle alarm device according to the first aspect detects a lane change operation by the lane operation detecting means and the detected distance is smaller than the caution distance, By activating the warning means, it is possible to reliably generate a warning according to the presence or absence of an approaching vehicle when changing lanes. According to a fourth aspect of the present invention, the distance measurement processing means of the vehicle obstacle warning device according to the first aspect is arranged such that the window located on the side closer to the own vehicle in the width direction of the entire image is located on the side farther from the own vehicle. Since the detection area is set by sequentially arranging a plurality of windows so as to be positioned higher in the height direction of the entire image than the located window, the detection area of the traveling vehicle closer to the own vehicle is more accurate. And the traveling vehicle on the side closer to the host vehicle can be detected relatively early.

[0011]

FIG. 1 shows an obstacle warning device for a vehicle according to the present invention. Here, the vehicle obstacle detecting device is mounted on the left and right door mirrors 11 of the vehicle 10 as shown in FIG.
D cameras C _R and C _L are provided, and a controller 1
2 is connected. Left and right stereo CCD cameras C _R , C _L
It is similarly configured, here mainly described the right camera C _R. The camera C _R is a pair of video cameras 13 and 14 which are arranged vertically, and the accommodation room 1 between the case 17 of the door mirror 11 and the half mirror 26 as shown in FIG.
11 is attached.

A pair of video cameras 13 and 14 are provided with a frame 15.
The bracket 18 is integrally connected to the mirror case 17 via the pin 16 while maintaining the vertical distance d.
Attached to. This pair of video cameras 13 and 14
The operation arm 20 of an actuator 19 for changing the imaging direction is pin-connected, and when the actuator 19 is driven, the two video cameras 13 and 14 rotate around the center line b of the pin 16 and the center line CL in the imaging direction (FIG. 2) can be moved in the horizontal direction. A pair of video cameras 1
3 and 14 are set to a reference position (rotation angle β = 0) during straight running as shown in FIG. 2 and equipped with a rear side image A0 as shown in FIG. Then, the rear side image is input to the controller 12 which constitutes a distance measurement processing means.

The main part of the controller 12 is constituted by a microcomputer, and an alarm control program and a distance measurement program, which will be described later, are stored and processed in a ROM (not shown). An input / output circuit (not shown) has left and right stereo CCD cameras. Each of the image signals s1 and s2 from C _R and C _L , the vehicle speed signal V from the vehicle speed sensor 22 and the lane change signals W _L and W _R from a turn signal (not shown) are input, and the buzzer 25 as a warning means is driven. An alarm output G can be output to the circuit 24. As shown in FIG. 4, the controller 12 has functions as a distance measurement processing unit B1, a relative speed detection unit B2, and an alarm control unit B3.

The distance measurement processing means B1 is divided into functions of an image data storage means, an image processing means, a distance measurement means, and a window arrangement setting means as described later. The general function is to store the entire image A0 (see FIG. 7) obtained from each of the video cameras 13 and 14, and to detect the detection area in which a plurality of windows w1,. Is extracted for each window, and the image shift amount τ (FIG. 6) is extracted for each window.
(See (b)), and the distances y1, y2,..., Y9 to the obstacle are measured for each window based on the deviation amount τ. At this time, in particular, the window arrangement setting means is located on the side closer to the own vehicle in the width direction of all images (right side in FIG. 7).
(For example, w9) is located on the side (left side in FIG. 7) far from the vehicle.
The window arrangement mode wm (see FIG. 7) of a plurality of windows w1,..., W9 can be set in advance so as to be positioned higher in the height direction of all images than in 1), and can be output.

A part of the image data storage means of the distance measurement processing means B1 fetches rear side images from the pair of video cameras 13 and 14 as a still inspection image (for example, all images A0 in FIG. 8) at appropriate times, The image data is filed in the latest inspection image data storage area in a predetermined image storage device. The image processing means sets the window arrangements w1, ..., w9 in the inspection image along the window arrangement mode wm, and describes the horizontal edges in each window as shown in FIGS. 6 (a) and 6 (b). To calculate the shift amount τ between the upper and lower edges.

FIGS. 6 (a) and 6 (b)
As shown in (1), when detecting a horizontal edge in each window, the same window, for example, w1 _H and w1 _L in the upper and lower inspection images from a pair of video cameras 13 and 14 is called, and all pixels in the window are called. The density value is divided into two levels of light and shade based on a predetermined threshold value, and further, for example, the change position of the binarized signal of each pixel is obtained along three edge determination lines L1, L2, L3, and each edge is determined. Trajectories corresponding to edges in the horizontal direction along the determination lines L1, L2, L3 (the determination lines L1, L2, L3
Left the same edge corresponding line (the same sloping line) D _H among each edge portion thus obtained is calculated as a straight line connecting schematically) along obtains each D _L, both edges corresponding line D _H, D _L
Is calculated. Further, the distance measuring means
The distance y ₁ to the obstacle (approaching vehicle) 1 from the shift amount τ obtained for each of the vertically opposed windows w1, to w9,
y ₂ , to y ₉ are obtained based on the principle of triangulation.

The operation of the vehicle obstacle warning device according to the present invention will now be described with reference to the warning control program and the distance measurement program shown in FIGS. In response to the turning on of an engine key (not shown), the controller 12 starts a main routine (not shown) of the vehicle obstacle alarm device, checks each function, and turns on a failure indicator (not shown) when a failure occurs. The alarm control routine and the distance measurement routine are reached at predetermined steps in the main routine, and each routine is executed. In the alarm control routine of FIG. 10, in step a1, current output data from each sensor is fetched and stored in a predetermined storage area. In step a2, the distance measurement processing is performed according to the subroutine of FIG.

Here, in the distance measurement routine of FIG.
In step s1, a pair of video cameras 13, 14
The current rear-side image from is acquired as a still inspection image, and the image data is stored in the latest inspection image data storage area in a predetermined image storage device. Steps s2 and s3
Then, the window arrangement mode wm is called, windows w1,..., W9 (see FIG. 7) are set in the inspection image along the set window arrangement mode wm, and the image of each window is extracted. In steps s4 and s5, the same window in the upper and lower inspection images from the pair of video cameras 13 and 14, for example, w1 _H and w1 _L (FIG. 6A,
(Refer to (b)), and perform arithmetic processing to divide the density values of all the pixels into two levels of light and shade. Then, three edge determination lines L
1, L2, L3 (preset), the inversion position (change position) of the binarized signal of each pixel is obtained, and the horizontal edge (inversion position) along each edge determination line L1, L2, L3. ) The upper and lower same edge equivalent lines along () (same slope line)
Find D _L and D _R. This processing is performed for each of the windows w1,.
Performed sequentially for each w9.

Furthermore, in step s6, s7, vertical same edge corresponding line (the same sloping line) D _L, calculates a shift amount τ is a vertical distance between D _R. The obstacle shift amount tau (approaching vehicle) distance y ₁ to 1, y _2, each window based a ~y ₉ the principle of triangulation w1, ~, respectively obtained for each w9, store in a predetermined storage area I do. Further, for example, the shortest distance information is selected from the distances y ₁ , y ₂ , to y ₉ information for each of the windows w 1, to w ₉ , and this is set to the approaching vehicle 1.
Is determined as the distance signal Y, and the value of the predetermined storage area is rewritten to the current distance signal Y, and the process returns to step a3. Thereafter, in steps a3 and a4, the distance signal Y of the closest vehicle 1 is called, and the window in which the distance data is obtained is set to w.
The direction of the approaching vehicle is calculated from the window and stored in a predetermined storage area. Further, the difference ΔY between the current distance Y _n and the previous distance Y _(n-1) (= Y _(n-1)
−Y _n ), and the same difference ΔY is time-differentiated (divided by the control cycle) to obtain a relative speed ΔV (= ΔY / dt). Then, the speed Vo (= ΔV + V) of the approaching vehicle 1 is calculated by adding the speed V of the own vehicle to the relative speed ΔV, and stored in a predetermined storage area.

When reaching step a5, the approaching vehicle 1 moves to the hatched area in FIG.
1 or a wide area K is determined. In this case, as shown in FIG. 5, in order to set the area K1 near the vehicle and the wide area K in advance, the windows w1,.
The thresholds ew1 to ew9 that define the area K1 near the vehicle and the thresholds Ew1 to Ew9 that define the wide area K are set in advance. As shown in FIG. 5, each of the threshold values ew1 to ew
9 and the threshold values Ew1 to Ew9 are set to be larger for windows located closer to the vehicle. by this,
Based on the direction (window number information) of the vehicle 1 approaching the window and the distance Y information, the position of the approaching vehicle 1 can be determined to be either the local area K1 or the wide area K.

The approaching vehicle 1 in step a5 is determined as the vehicle near the area K1, reaches the step a6, a7, here determines the input of the lane change signal W _L, W _R,
When no input is made, the process returns to the main routine.
On the other hand, at the time of input, the lane change signal calls the warning distance calculation map m2 (for the own vehicle vicinity area K1) m2 in FIG. 9 and judges the necessity of alarm output along the map, and outputs the alarm output G to the drive circuit 24 when necessary. The signal is output to the buzzer 25, and the process returns to the main routine. The guard distance calculation map m2 used here and a guard distance calculation map described later (wide area K
M1 is stored in the ROM (not shown) of the controller 12 in advance. The warning distance calculation map m2 is determined according to the own vehicle speed V and the relative speed ΔV of the approaching vehicle so as to avoid a collision with an approaching motorcycle or other vehicles in the own vehicle vicinity area K1 when the own vehicle changes lanes. The warning distance E1 _n (m) in the danger area is set respectively. Similarly, the caution distance calculation map m1 indicates the own vehicle speed V and the relative speed Δ of the approaching vehicle so as to avoid a collision with a vehicle in the wide area K when the own vehicle changes lanes.
Warning distance E _n of Critical in accordance with the V (m) are respectively set.

Here, the guard distance E1 _n (m) set in the guard distance calculation map m2 is set larger than the guard distance E _n (m) set in the guard distance calculation map m1. Therefore, when an approaching vehicle is present in the area K1 near the host vehicle, a warning is issued relatively quickly so that a collision with the approaching vehicle in the area K1 near the host vehicle can be avoided when changing lanes. Similarly, the caution distance calculation map m1 is based on the own vehicle speed V and the relative speed ΔV of the approaching vehicle so as to avoid a collision with a vehicle in the wide area K when changing lanes of the own vehicle. E _n (m) are set respectively. On the other hand, the approaching vehicle 1 in step a5 is determined as a wide area K, reaches the step a8, a9, where determines input of a lane change signal W _L, W _R, at the time of non-input control returns directly to the main routine . On the other hand, at the time of input, the warning distance calculation map m1 of FIG. 8 is called, and the necessity of alarm output is determined along the map,
When necessary, the alarm output G is sent to the buzzer 25 via the drive circuit 24.
And returns to the main routine.

As described above, the vehicle obstacle warning device shown in FIG. 1 uses a plurality of windows w from all images obliquely behind the vehicle.
An image of a detection area formed by arranging 1,..., W9 is extracted, a shift amount τ of a pair of camera images is detected for each window, and distances y ₁ and y to obstacles are determined based on the shift amount. ₂ , ~
measured y _9, of the distance to the obstacle, the shortest distance information and distance signal Y _n of the approaching vehicle 1, by differentiating the difference ΔY of this distance Y _n and the previous distance Y _(n-1) Relative velocity ΔV (= ΔY /
dt). On top of that, the distance between the obstacle in time alert distance (m) is smaller than that determined by the vehicle speed and the relative speed, a lane change signal W _L, activating the buzzer 25 upon input of the W _R. For this reason, it is possible to reliably avoid the danger of collision with the approaching vehicle at the time of lane change. In the above, the stereo CCD cameras C _R , C _L
Has been described as inactive, but instead, the turning radius of the vehicle is determined based on the steering wheel angle signal and the vehicle speed signal of the vehicle,
The video camera inside the turning direction may be rotated and adjusted by an amount corresponding to the turning radius so that an obstacle necessary for running safety can be detected more reliably and earlier.

Furthermore, the vehicle obstacle alarm device of FIG. 1, a stereoscopic CCD camera C _R, but the C _L was obliquely rearward of the vehicle, instead of this, may be directed obliquely forward, this Also in this case, it is possible to avoid collision with the parallel running vehicles in the area K1 near the own vehicle and the wide area K, and the same operation and effect can be obtained.

[0025]

As described above, according to the first aspect of the present invention, an image of a detection area in which a plurality of windows are formed side by side is extracted from all the images obliquely forward or obliquely rearward of the vehicle. The amount of displacement between the images of the pair of cameras is detected, the distance to the obstacle is measured based on the amount of displacement, and the relative speed detection means detects the relative speed based on the change in the distance to the obstacle, and the relative speed is determined. When the distance is smaller than the caution distance determined by the vehicle speed and the relative vehicle speed, the warning means is activated, so that the presence of a vehicle traveling in the adjacent lane is reliably detected, and the collision of approaching vehicles when changing lanes is reliably prevented. it can.

According to a second aspect of the present invention, in particular, the distance from the obstacle is compared with a threshold value which is set for each window and which is set closer to the vehicle in the width direction of the entire image and closer to the own vehicle. Can accurately detect the presence of a vehicle traveling in the area near the own vehicle (own lane), and if the detection distance is smaller than the threshold, there is a vehicle traveling in the area near the own vehicle. Since the warning distance is determined to be large by judging that there is a vehicle, it is possible to issue an early warning to an approaching vehicle traveling on a side closer to the own vehicle.

According to the third aspect of the present invention, when the lane change operation is detected and the detected distance is shorter than the caution distance, the alarm means is activated. Can be generated. The invention according to claim 4 is such that the window located on the side closer to the own vehicle in the width direction of the entire image is positioned higher in the height direction of the entire image than the window located on the side farther from the own vehicle. Since the detection area is set by sequentially arranging a plurality of windows, the detection area can be set along the traveling locus of the vehicle, and the detection area of the traveling vehicle closer to the own vehicle can be more accurately determined. As a result, the erroneous detection of the traveling vehicle close to the own vehicle can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an obstacle warning device for a vehicle according to the present invention.

FIG. 2 is a schematic plan view of a vehicle equipped with the vehicle obstacle warning device of FIG. 1;

FIG. 3 is a cutaway sectional view of a main part of a door mirror equipped with a pair of video cameras used by the vehicle obstacle warning device of FIG. 1;

FIG. 4 is a functional block diagram of a controller of the vehicle obstacle warning device of FIG. 1;

FIG. 5 is an explanatory diagram of an area adopted in a window of a vehicle equipped with the vehicle obstacle warning device of FIG. 1;

6 (a) and 6 (b) are explanatory views of a deviation amount detection performed by the vehicle obstacle alarm device of FIG. 1, wherein (a) shows a binarized image in an upper window and (b) shows a binarized image in a lower window.

FIG. 7 is a schematic diagram of all images captured by a video camera by the vehicle obstacle warning device of FIG. 1;

FIG. 8 is an explanatory diagram of a warning distance calculation map for a wide area used by the vehicle obstacle warning device of the present invention.

FIG. 9 is an explanatory diagram of a warning distance calculation map of an area near the own vehicle used by the vehicle obstacle warning device of the present invention.

FIG. 10 is a flowchart of an alarm control program executed by the vehicle obstacle alarm device of the present invention.

FIG. 11 is a flowchart of a distance measurement control program executed by the vehicle obstacle warning device of the present invention.

FIG. 12 is a schematic diagram of all images captured by a video camera by a conventional vehicle obstacle warning device. DESCRIPTION OF SYMBOLS 1 Object (other vehicle) 10 Vehicle 11 Door mirror 12 Controller 13 Video camera 14 Video camera 22 Vehicle speed sensor 25 Buzzer τ Image shift amount y ₁ Distance signal y ₂ Distance signal d Vertical distance between a pair of video cameras w1 Window w9 Window w1 window wm window sequence mode in the window w1 _L under examination images in _H on the inspection image C _R stereo type CCD camera C _L centerline E warning distance of the stereo type CCD camera CL imaging direction E1 warning distance V vehicle speed signal Y distance signal s1 Image signal s2 Image signal G Alarm output B1 Distance measurement processing means B2 Relative speed detection means B3 Alarm control means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaki Tani 5-33-8 Shiba, Minato-ku, Tokyo, Mitsubishi Motors Corporation (56) References JP-A-6-265351 (JP, A) JP-A-6-214014 (JP, A) JP-A-4-269618 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 3/00-3/32 B60R 21/00 620 G06T 1/00 G08B 21/00 G08G 1/16 G05D 1/02

Claims (4)

(57) [Claims] A plurality of windows are formed side by side in the width direction of a full image from a pair of cameras provided so as to photograph diagonally forward or diagonally backward of the vehicle, and all images obtained from each camera. Distance measurement processing for extracting an image of a portion corresponding to a detection area for each of the above windows, detecting a shift amount of the image for each corresponding window, and measuring a distance to an obstacle for each window based on the shift amount. Means, relative speed detection means for detecting a relative speed based on a change in the distance to the obstacle detected by the distance measurement processing means, vehicle speed detection means for detecting the vehicle speed, and alarm means for alarming the presence of the obstacle. An alarm control unit that activates the alarm unit when the distance to the obstacle detected by the distance measurement processing unit is smaller than a warning distance determined by the vehicle speed and the relative vehicle speed. The vehicle obstacle warning device that. 2. The vehicle obstacle warning device according to claim 1, wherein the warning control means sets a distance from the obstacle detected by the distance measurement processing means for each window, and sets a distance in a width direction of the entire image. In the above, the window located closer to the own vehicle is compared with a threshold that is set larger, and when the detection distance is smaller than the threshold, the warning distance is determined to be larger than when the detection distance is larger. Vehicle obstacle alarm device. 3. An obstacle warning device for a vehicle according to claim 1, further comprising a lane operation detecting means for detecting an occupant's lane changing operation, wherein said alarm means detects said lane changing operation,
An obstacle warning device for a vehicle, wherein the warning means is activated when the detection distance is smaller than the warning distance. 4. The obstacle warning device for a vehicle according to claim 1, wherein the distance measurement processing means is arranged such that a window located on a side closer to the own vehicle in a width direction of the entire image is located on a side farther from the own vehicle. An obstacle warning device for a vehicle, wherein the detection area is set by sequentially arranging the plurality of windows so as to be positioned higher in the height direction of the entire image than the windows.