JPH07332968A - Inter-vehicle distance measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] To enable accurate measurement of the distance to an obstacle with a small amount of calculation. [Structure] Light is emitted from a laser light projecting means 10, left and right image pickup means 11 and 13 capture an image including reflected light, and left and right projected light position detecting means 12 and 14 determine the position of the reflected light in the image. Then, the parallax calculation unit 15 calculates the parallax, and the distance detection unit 16 uses the triangulation from the parallax calculated by the parallax detection unit 15 and the distance between the left and right imaging units 11 and 13 which is calculated in advance, and the distance to the front obstacle. And the inter-vehicle distance warning means 17 informs the driver of it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can detect the reflected light when the spot light from a laser light projecting means mounted on the front of a vehicle is reflected from an obstacle and measure the distance to the obstacle ahead. The present invention relates to an inter-vehicle distance measuring device.

[0002]

2. Description of the Related Art As an example of a conventional inter-vehicle distance measuring device,
There is a method in which an area where a vehicle ahead exists is set in one image and the distance to the vehicle ahead is obtained by correlating the area with the image in the other (JP-A-4-41941).

[0003]

As described above, the conventional inter-vehicle distance measuring apparatus extracts the front vehicle region from one of the two image data and calculates the distance to the front vehicle by correlating with the other image. As a result, the amount of calculation is large and the processing takes time, which may prevent accurate inter-vehicle distance measurement. Further, since the distance to the vehicle is calculated from the correlation value of the entire vehicle, it is not possible to accurately measure the inter-vehicle distance.

The present invention solves the above problem, and an object of the present invention is to provide an inter-vehicle distance measuring device for determining the distance from the position of reflected light on the left and right image planes to an obstacle ahead. It is another object of the present invention to provide an inter-vehicle distance measuring device that determines the positions of a large number of reflected lights on the left and right image planes by changing the projection direction of spot light and finds the distance to the nearest obstacle. . Also, by changing the projection direction of the spot light, the positions of many reflected lights on the image plane are obtained, and the distance to the obstacle is calculated by comparing the positions of the reflected lights on the image plane at a predetermined reference distance. It is an object of the present invention to provide an inter-vehicle distance measuring device according to the above.

[0005]

In order to solve the above problems, a first means of the present invention is a laser light projecting means for projecting a laser light to the front of a vehicle, and a means for projecting from the laser light projecting means. Left image pickup means for picking up light reflected by an obstacle in front of the vehicle and light reflected from an obstacle in front of the vehicle is detected from image data from the left image pickup means, and a position in the image is calculated. A right image pickup for picking up the light projected from the laser light projecting means, which is placed on the right side of the left light projecting light position detecting means and on the right side of the left image pickup means and has an optical axis parallel to each other. Means, right projection light position detecting means for detecting reflected light from an obstacle in front of the vehicle from image data from the right imaging means, and calculating a position in the image, and left projection light position detecting means. Position of the projected light in the image from Parallax calculation means for calculating the parallax from the projected light position in the image from, and distance detection for detecting the distance to the obstacle from the parallax calculated by the parallax calculation means and the distance between the left imaging means and the right imaging means Means and inter-vehicle distance warning means for informing the driver of the distance from the distance detection means to the obstacle, and the left imaging means when the spot light from the laser light projecting means is reflected from the obstacle. The distance from the position on the image of each of the right imaging means to the obstacle ahead is measured.

A second means of the present invention is a laser light projecting means for projecting a laser light to the front of the vehicle, and a light projected from the laser light projecting means and reflected from an obstacle in front of the vehicle. A left image pickup means for picking up an image, and a right image pickup means placed on the right side of the left image pickup means, having parallel optical axes, for picking up light emitted from the laser light projecting means and reflected from an obstacle in front of the vehicle. A mirror rotation means for rotating a mirror for changing the direction of light of the laser light projecting means; a left image memory means for storing image data from the left imaging means using a rotation signal of the mirror rotation means; The left projection light position detection means for detecting the light reflected from the obstacle in front of the vehicle at each mirror rotation angle from the left image memory means and calculating the position in the image, and the rotation signal of the mirror rotation means. Using the right imaging Right image memory means for storing image data from the step, and right light projection for detecting light reflected from an obstacle in front of the vehicle at each mirror rotation angle from the right image memory means and calculating the position in the image. The light position detecting means, and the respective mirror rotation angles from the position in the image of the reflected light from the obstacle in front of the vehicle at the respective mirror rotation angles from the left projection light position detection means and the right projection light position detection means. Parallax calculation means for calculating the parallax at, the minimum distance detection means for detecting the minimum distance from the largest value of the parallax at each mirror rotation angle in the parallax calculation means, obstacles from the minimum distance detection means An inter-vehicle distance warning means for informing the driver of the distance to the vehicle is provided, and an image of each of the left imaging means and the right imaging means when the spot light from the laser light projecting means is reflected from an obstacle at each mirror rotation angle In the upper position It is obtained so as to measure the distance to a forward obstacle.

A third means of the present invention is a laser light projecting means for projecting a laser light to the front of the vehicle, and a light projected from the laser light projecting means and reflected from an obstacle in front of the vehicle. Image capturing means for capturing an image, mirror rotating means for rotating a mirror that changes the direction of light of the laser light projecting means, and image memory means for storing image data from the image capturing means using a rotation signal of the mirror rotating means. A projection light position detecting means for detecting light reflected from an obstacle in front of the vehicle at each mirror rotation angle from the image memory means and calculating a position in the image; and the projection light position detecting means. Displacement distance detecting means for detecting the distance of the obstacle with respect to the reference distance from the difference between the position of the reflected light in the image from and the position of the reflected light in the image when the object is present at a predetermined reference distance, and If the displacement amount with respect to the reference distance detected by the displacement distance detecting means is closer to the center of the image than the reference position, an obstacle approach warning means for notifying the driver of the approach of the obstacle is provided, and the spot light from the laser light projecting means is provided. Measure the distance to the obstacle from the difference between the position on the image when reflected from the obstacle at each mirror rotation angle and the position on the image of the spot light at each mirror rotation angle at a predetermined reference distance. It was done like this.

[0008]

With the above-described first structure, when the spot light from the laser light projecting means mounted in front of the vehicle is reflected from the obstacle, the left image pickup means and the right image pickup means are forwarded from the respective positions on the image. The distance to the obstacle can be measured accurately.

Further, according to the second structure, from the position on the image of each of the left image pickup means and the right image pickup means when the spot light from the laser light projecting means is reflected from the obstacle at each mirror rotation angle. By measuring the distance to the obstacle ahead, the distance from the own vehicle to the nearest obstacle can be accurately measured.

Further, according to the third structure, the spot light from the laser light projecting means is reflected on the mirror at each mirror rotation angle at each position on the image and each mirror rotation angle at a predetermined reference distance. The distance to the obstacle can be measured from the difference between the spot light position on the image and the spot light position.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an inter-vehicle distance measuring device according to a first embodiment of the present invention. In FIG. 1, reference numeral 10 is a laser beam projecting means for projecting a laser beam to the front of the vehicle.
Reference numeral 11 denotes a left imaging means for imaging the light projected from the laser light projection means 10 and reflected from an obstacle in front of the vehicle.
Reference numeral 12 denotes a left projection light position detection means for detecting the light projected from the laser projection means 10 on the basis of the image data from the left image pickup means 11 and reflected from an obstacle in front of the vehicle and calculating the position in the image. is there. Reference numeral 13 is a right image pickup means which is placed on the right side of the left image pickup means 11 and has optical axes parallel to each other and which images the light projected from the laser light projecting means 10 and reflected from an obstacle in front of the vehicle. Reference numeral 14 denotes a right projection light position detection means for detecting the light projected from the laser projection means 10 based on the image data from the right image pickup means 13 and reflected from an obstacle in front of the vehicle, and calculating the position in the image. is there. Reference numeral 15 is a parallax calculating means for calculating a parallax from the projected light position in the image from the left projected light position detecting means 12 and the projected light position in the image from the right projected light position detecting means 14. 16 is the parallax calculation means 1
It is a distance detecting unit that detects the distance to the obstacle from the parallax calculated in step 5 and the interval between the left imaging unit 11 and the right imaging unit 13. Reference numeral 17 is an inter-vehicle distance warning means for informing the driver of the distance from the distance detection means 16 to the obstacle.

Next, the operation of the above configuration will be described. Visible laser light is emitted to the front of the vehicle from the laser light projecting means 10. If there is an obstacle such as a vehicle ahead of the vehicle, the laser light emitted from the laser light projecting means 10 hits the obstacle and is reflected. Then, the left image pickup means 11 and the right image pickup means 13 capture images including reflected light.
At this time, in order to easily find the position of the reflected light in the image, a filter that passes only the wavelength of the laser light is attached to the left image pickup means 11 and the right image pickup means 13, and the laser light projecting means 1 is further attached.
The optical axis is set on the same horizontal plane including 0. In the left projected light position detecting means 12 and the right projected light position detecting means 14,
As shown in FIG. 2, only the reflected light is detected from the images from the left image pickup means 11 and the right image pickup means 13, and the positions dl and dr of the reflected light from the respective left ends are obtained. The parallax calculator 15 calculates the parallax dlr as follows.

Dlr = dl-dr Further, the distance D to the front obstacle using the triangulation from the parallax dlr obtained by the parallax calculating unit 15 in the distance detecting unit 16 and the distance dc between the left and right image pickup units previously obtained.
Ask for.

D = f · (dc / dlr) The inter-vehicle distance warning means 17 informs the driver of the measured inter-vehicle distance. FIG. 3 is a block diagram of an inter-vehicle distance measuring device according to a second embodiment of the present invention. In FIG. 3, reference numeral 30 is a laser beam projecting means for projecting a laser beam to the front of the vehicle.
Reference numeral 31 is a left imaging means for imaging the light projected from the laser light projection means 30 and reflected from an obstacle in front of the vehicle.
Reference numeral 32 is a right image pickup means which is placed on the right side of the left image pickup means 31 and has optical axes parallel to each other and which picks up the light projected from the laser light projecting means 30 and reflected from an obstacle in front of the vehicle. 33
Is a mirror rotating means for rotating a mirror that changes the direction of the light of the laser light projecting means 30. Reference numeral 34 is a left image memory means for storing the image data from the left image pickup means 31 using the rotation signal of the mirror rotation means 33. Reference numeral 35 is a left projection light position detecting means for detecting the light reflected from the obstacle ahead of the vehicle at each mirror rotation angle from the left image memory means 34 and calculating the position in the image. Reference numeral 36 is a right image memory means for storing the image data from the right image pickup means 32 using the rotation signal of the mirror rotation means 33. Reference numeral 37 is a right projection light position detecting means for detecting the light reflected from the obstacle in front of the vehicle at each mirror rotation angle from the right image memory means 36 and calculating the position in the image. 38 is a parallax at each mirror rotation angle from the position in the image of the reflected light from the obstacle in front of the vehicle at each mirror rotation angle from the left projection light position detection means 35 and the right projection light position detection means 37. Is a parallax calculation means for calculating. Reference numeral 39 is a minimum distance detecting means for detecting the minimum distance from the largest value of the parallax at each mirror rotation angle in the parallax calculating means 38. Reference numeral 40 is an inter-vehicle distance warning means for informing the driver of the distance from the minimum distance detection means 39 to the obstacle.

Next, the operation of the above configuration will be described. Visible laser light is reflected by the mirror rotating means 33 from the laser light projecting means 30 to the front of the vehicle, and the projection direction is changed in the horizontal or vertical direction to irradiate the visible laser light. If there is an obstacle such as a vehicle ahead of the vehicle, the laser light emitted from the laser light projecting means 10 hits the obstacle and is reflected. Then, the left image pickup means 31 and the right image pickup means 32 capture images including reflected light. At this time, in order to easily obtain the position of the reflected light in the image, a filter that passes only the wavelength of the laser light is attached to the left image pickup means 31 and the right image pickup means 32, and the laser light projecting means 30 is also included to emit light on the same horizontal plane. Install the shaft. In the left image memory means 34 and the right image memory means 36, the left image pickup means 31 at different light projection positions according to the mirror rotation angle signal and the rotation end signal from the mirror rotation means 33.
And the images from the right image pickup means 32 are stored. In the left and right projected light position detecting means 35 and 37, the n images stored at the left image memory means 34 and the right image memory means 36 at respective mirror rotation angles are reflected on the image of the reflected light as shown in FIG. The positions dln and drn are obtained, and the parallax calculating means 38 calculates the parallax dlrn at each mirror rotation angle. The minimum distance detecting means 39 selects the object dlrmax having the largest parallax as follows, and calculates the distance Dmin of the object closest to the front obstacle according to the value. That is, dlrmax = max (dlr1, dlr2, ..., dl
rn), Dmin = f · (dc / dlrmax) is calculated. The inter-vehicle distance warning means 40 notifies the driver of this.

FIG. 5 is a block diagram of an inter-vehicle distance measuring device according to a third embodiment of the present invention. In FIG. 5, 50
Is a laser beam projecting means for projecting a laser beam to the front of the vehicle. Reference numeral 51 is an image pickup means for picking up the light projected from the laser light projecting means 50 and reflected from an obstacle in front of the vehicle. Reference numeral 52 is a mirror rotating means for rotating a mirror that changes the direction of the light of the laser light projecting means 50. Reference numeral 53 is an image memory means for storing the image data from the image pickup means 51 using the rotation signal of the mirror rotation means 52. Reference numeral 54 is a projection light position detecting means for detecting the light reflected from the obstacle in front of the vehicle at each mirror rotation angle from the image memory means 53 and calculating the position in the image. Reference numeral 55 indicates the distance of the obstacle with respect to the reference distance from the difference between the position of the reflected light in the image from the projected light position detecting means 54 and the position of the reflected light in the image when an object exists at a predetermined reference distance. It is a displacement distance detecting means for detecting. Reference numeral 56 denotes obstacle approach warning means for notifying the driver of approach of the obstacle if the displacement amount with respect to the reference distance detected by the displacement distance detecting means 55 is closer to the center of the image than the reference position.

Next, the operation of the above configuration will be described. Visible laser light is reflected from the laser light projecting means 50 toward the front of the vehicle by the mirror rotating means 52, and the projected direction is changed to a preset horizontal or vertical direction for irradiation. If there is an obstacle such as a vehicle ahead of the host vehicle, the laser light emitted from the laser light projecting means 50 hits the obstacle and is reflected. Then, the image pickup means 51 captures an image including reflected light. At this time, in order to easily find the position of the reflected light in the image, a filter that passes only the wavelength of the laser light is attached to the image pickup means 51, and the optical axis is set on the same horizontal plane including the laser light projecting means 50. In the image memory 53, images from the image pickup means 51 at different light projection positions are stored according to the mirror rotation angle signal and the rotation end signal from the mirror rotation means 52. As shown in FIG. 6, after projecting light in one set spatial direction, the projected light position detecting means 54 is determined from the image data stored in the image memory 53 in each direction.
Each reference reflected light position Rpdim at the distance Ddim from the own vehicle and each reflected light position Rp at this time
To find the distance traveled within the image. The displacement distance detecting means 55 calculates the distance to the front obstacle as follows.

Ddem = fp (Rp−Rpdim) + Ddim Here, Ddem is a calculated distance, and fp is a proportional constant and is a ratio of the moving distance of the reflected light on the image when the obstacle is moved by a unit distance. The distance at the position in each image is calculated according to this equation, and when the obstacle approach warning means 56 calculates a distance smaller than the threshold distance Dth among the calculated forward obstacles, the driver is warned.

[0019]

As described above, according to the present invention, the distance to an obstacle can be measured with a small amount of calculation, and the distance to the nearest obstacle can be accurately measured. Can measure distance.

[Brief description of drawings]

FIG. 1 is a block diagram of an inter-vehicle distance measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram of an input image in the inter-vehicle distance measuring device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of an inter-vehicle distance measuring device according to a second embodiment of the present invention.

FIG. 4 is a diagram of an input image in the inter-vehicle distance measuring device according to the second embodiment of the present invention.

FIG. 5 is a block diagram of an inter-vehicle distance measuring device according to a third embodiment of the present invention.

FIG. 6 is a diagram of an input image in the inter-vehicle distance measuring device according to the third embodiment of the present invention.

[Explanation of symbols]

 10, 30, 50 Laser light projecting means 11, 31 Left imaging means 12, 35 Left projected light position detecting means 13, 32 Right imaging means 14, 37 Right projected light position detecting means 15, 38 Parallax calculating means 16 Distance Detecting means 17, 40 Inter-vehicle distance warning means 33, 52 Mirror rotating means 34 Left image memory means 36 Right image memory means 39 Minimum distance detecting means 51 Imaging means 53 Image memory means 54 Projected light position detecting means 55 Displacement distance detecting means 56 Obstacle approach warning means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G08G 1/16 CE // G05D 1/02 S

Claims (3)

[Claims] 1. A laser beam projector for projecting a laser beam to the front of the vehicle, a left imager for capturing light projected from the laser beam projector and reflected from an obstacle in front of the vehicle, and Left projection light position detecting means for detecting reflected light from an obstacle in front of the vehicle from image data from the left imaging means and calculating a position in the image, and an optical axis placed on the right side of the left imaging means. Are parallel to each other and the right imaging means for imaging the light projected from the laser light projecting means and reflected from the obstacle in front of the vehicle, and the reflected light from the obstacle in front of the vehicle from the image data from the right imaging means The right projected light position detecting means for detecting the position in the image and the projected light position in the image from the left projected light position detecting means and the image from the right projected light position detecting means. A parallax calculation means for calculating a parallax from the light projection position in the interior, Distance detecting means for detecting the distance to the obstacle from the parallax calculated by the parallax calculating means and the distance between the left image pickup means and the right image pickup means, and the inter-vehicle distance for notifying the driver of the distance from the distance detector to the obstacle Distance warning means is provided to measure the distance from the position on the image of each of the left imaging means and the right imaging means to the obstacle ahead when the spot light from the laser light projecting means is reflected from the obstacle. An inter-vehicle distance measuring device configured as described above. 2. A laser light projecting means for projecting laser light to the front of the vehicle, a left imaging means for imaging light projected from the laser light projecting means and reflected from an obstacle in front of the vehicle, Right imaging means, which is placed on the right side of the left imaging means and has parallel optical axes, images the reflected light from an obstacle in front of the vehicle which is projected from the laser light projecting means, and the light of the laser light projecting means. The mirror rotation means for rotating the mirror, the left image memory means for storing the image data from the left image pickup means using the rotation signal of the mirror rotation means, and the respective mirror rotation angles from the left image memory means. In the image from the right imaging means using the left projection light position detecting means for detecting the light reflected from the obstacle in front of the vehicle and calculating the position in the image, and the rotation signal of the mirror rotating means. Store data Right image memory means, right light projection position detecting means for detecting light reflected from an obstacle ahead of the vehicle at each mirror rotation angle from the right image memory means, and calculating a position in the image; Parallax for calculating the parallax at each mirror rotation angle from the position in the image of the reflected light from the obstacle in front of the vehicle at each mirror rotation angle from the left projection light position detection means and the right projection light position detection means The calculating means, the minimum distance detecting means for detecting the minimum distance from the largest value of the parallax at each mirror rotation angle in the parallax calculating means, and the distance from the minimum distance detecting means to the obstacle to the driver. An inter-vehicle distance warning means is provided for notifying, and when the spot light from the laser light projecting means is reflected from an obstacle at each mirror rotation angle, obstacles ahead of the left image capturing means and the right image capturing means on the respective images. Measure the distance to an object Vehicle distance measuring apparatus constructed in so that. 3. A laser light projecting means for projecting a laser light to the front of the vehicle, and an imaging means for imaging light projected from the laser light projecting means and reflected from an obstacle in front of the vehicle.
Mirror rotating means for rotating a mirror that changes the direction of light of the laser light projecting means, image memory means for storing image data from the image pickup means using a rotation signal of the mirror rotating means, and the image memory means From the projected light position detection means for detecting the light reflected from the obstacle in front of the vehicle at each mirror rotation angle and calculating the position in the image,
The distance of the obstacle with respect to the reference distance is detected from the difference between the position of the reflected light in the image from the projection light position detection means and the position of the reflected light in the image when an object exists at a predetermined reference distance. Displacement distance detecting means and obstacle approach warning means for notifying a driver of approaching an obstacle if the displacement amount with respect to the reference distance detected by the displacement distance detecting means is closer to the center of the image than the reference position are provided. Obstacle due to the difference between the position on the image when the spot light from the light means is reflected from the obstacle at each mirror rotation angle and the position on the image at the mirror rotation angle at each predetermined reference distance. An inter-vehicle distance measuring device configured to measure the distance to an object.