JPH03231112A - Apparatus for detecting distance between vehicles in order to follow preceding vehicle - Google Patents

Abstract

PURPOSE:To set a tracking window on the image of a preceding vehicle readily even in driving a vehicle and to find the vehicle which is followed by own's vehicle among a plurality of vehicle images. CONSTITUTION:When an image tracking instruction switch 13 is operated, a computer 10 reads the image signal in a window 14 which is following a preceding vehicle 5a out of a memory 9. The signal is made to be a reference image signal for operating the distance between the vehicles. The region wherein the image signal of an image sensor 3 corresponds to the window 14 in a memory 8 is selected with the computer 10. Each picture element of the image signal in the memory 8 is sequentially shifted with respect to the reference image signal. The total sum of the absolute values of the signals for every right and left elements is operated. Then, the right and left picture elements are compared. The shifted amount of the picture element when the total sum of the absolute values of the difference signals becomes the minimum value is made to be (n). The pitch of the picture elements is made to be P. The reference length of the optical system is made to be L. The focal distances of lenses 1 and 2 are made to be (f). The distance to the preceding vehicle 5 is made to be R. Then, R can be obtained by R=f.L/nP.

Description

[Detailed Description of the Invention] Industrial Application Field] The present invention relates to an optical distance detection device using an image sensor, and in particular to an inter-vehicle distance detection device that continuously measures the inter-vehicle distance between a preceding vehicle and the host vehicle. It is something.

[Prior Art] Conventionally, optical distance detection devices using image sensors have been disclosed, for example, in Japanese Patent Publications No. 63-38085 and Japanese Patent Publication No. 63-46363. Each of these has two left and right optical systems as shown in FIG. 5, and these left and right optical systems are placed apart by the base line length and are composed of lenses 1.2. Separate image sensors 3.
4 is provided, and the image sensor 3 is provided in the signal processing device 20.
, 4 are electrically superimposed while sequentially softening them, and the distance jlIR to the object 21-L is determined by the principle of triangulation from the shift amount l when the above two image signals match best. − is required.

On the other hand, a method for tracking an image of a preceding vehicle captured by an image sensor or the like is disclosed, for example, in Japanese Patent Publication No. 33352/1983. According to this, the target is image-tracked by the operator setting a tracking gate (window) surrounding the target to be tracked on the display screen while looking at the display screen.

[Problems to be Solved by the Invention] The optical distance detection device using the image sensor described above and the preceding vehicle image tracking device are combined to continuously detect the inter-vehicle distance to the preceding vehicle to be followed. Configuration 5: Inter-vehicle distance detection device;
As disclosed in the publication, it is almost impossible for the driver to create a window (tracking case) with a similar shape to the image of the preceding vehicle while driving the vehicle using a joystick, trackball, mouse, etc. .

This invention was made in order to solve the above-mentioned problems, and it is possible to easily set the tracking window to the image of the vehicle in front even when the vehicle is driving, and to keep track of the vehicle even when multiple vehicles are running in front. To provide an inter-vehicle distance detecting device for tracking a preceding vehicle, which can determine which preceding vehicle is being followed and detecting the inter-vehicle distance.

[Means for Solving the Problems 3] An inter-vehicle distance detection device for tracking a preceding vehicle according to the present invention, (c) an image sensor for capturing an image of the preceding vehicle, and a display means for displaying a static image from the image sensor. An image tracking window pre-displayed at a predetermined position on this display means, an image tracking instruction switch 2,000 that can be operated by the driver, and when an image of a preceding vehicle enters the image tracking window, the image tracking is performed. The vehicle is equipped with an image tracking means for image tracking the image of the preceding vehicle by operating the instruction switch 52, and a detection means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle displayed in the image tracking window. Features.

[For production]

In this invention, the image tracking window is displayed in advance at a predetermined position of the display means, for example, in the center, and when a preceding vehicle that is following is displayed on the display device, this image of the preceding vehicle is displayed in the image tracking window. Drive your vehicle so that it enters the window. When the image of the preceding vehicle enters the window, the image tracking instruction switch is operated, and thereafter the window automatically tracks the image of the preceding vehicle.

First Embodiment: Hereinafter, one embodiment of the second invention will be described with reference to the drawings. 1st
The figure shows a configuration diagram of an inter-vehicle distance detection device for tracking a preceding vehicle according to the present invention, and in the figure, 1. 2 is a lens that constitutes the 151 pairs of optical system on the left, 3 and 4 are two-dimensional image sensors arranged corresponding to this lens I and 2, 5 is a preceding vehicle that follows, and 6.7 is the above image An analog-to-digital converter for converting the analog signal from the sensor 3.4 into a digital signal, 8.9 a memory for storing the image signal of the image sensor 34, 10 a microcomputer, and 11 the image sensor 4 on the right side. This is a display that displays captured images, and is controlled by the microcomputer 10. 12 is a device for forming a window for image tracking. 13 is an image tracking instruction switch operated by the driver.

Next, the operation will be explained. For example, if an image 5a of a preceding vehicle to be followed appears on the image of the right image sensor 4 and is displayed on the display 11 as shown in FIG. The relative position of the vehicle is changed to move the preceding vehicle image 5a to a position within the image tracking window 14 displayed on the false display IT. As shown in FIG. 3, when the image 5a of the preceding vehicle has completely entered the window 14, when the driver operates the image tracking switch 13, the image of the preceding vehicle will be displayed on the screen of the display 11. No matter how the vehicle 5a moves, the window 14 moves accordingly, and the image tracking function of the preceding vehicle image 5a by the window I4 is automatically performed. This image tracking function was developed using the
This device is similar to the conventional device disclosed in Japanese Patent Publication No. 1-35305.

Next, a method for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle will be explained. First, the microcomputer 10 uses the preceding vehicle image 5a.
A pixel signal within the window 14 that is being tracked is read out from the memory 9 and used as a reference image signal for calculating the inter-vehicle distance. Then, the microcomputer 10 selects an area corresponding to India 14 in the memory 8 where the image signal of the left image sensor 3 is stored, and converts the image signal of the memory 8 to the reference image signal. The sum of the absolute values of the signals for each left and right pixel is calculated while shifting one pixel at a time. That is, the position of the image that most closely matches the image within the window 14 is determined by sequentially shifting one pixel at a time. At this time, as shown in FIG. 4, the region involved in the calculation corresponds to the region 15 of the image in the memory 8 with respect to the reference image signal in the window 14. Compare the left and right pixels as described above, and let the soft amount of the pixel when the sum of the absolute values of the difference signals is the minimum be n pixels, the pitch of the pixels be P, the baseline length of the optical system, and the lens 1 Let f be the power point distance of .2, and let R be the distance to the preceding vehicle 5, then R can be found by the following formula.

R-r L P In this way, even if the preceding vehicle (vehicle 5) moves to the left or right, it is possible to track the preceding vehicle and continuously calculate the inter-vehicle distance from the own vehicle. can.

〔Effect of the invention〕

As explained above, according to the present invention, when the image of the preceding vehicle enters the image tracking window that is preset and displayed on the display means and the image tracking instruction switch is operated, the image of the preceding vehicle is displayed through the image tracking window. Since the image tracking function is performed, the driver can easily start image tracking of the preceding vehicle by simply operating the image tracking instruction switch while driving. In addition, since the window frame and the image of the preceding vehicle within the window are always displayed on the display, even when multiple preceding vehicles are running, the driver can accurately determine the distance between the vehicle and the vehicle in front of the vehicle being followed. Distance can always be detected.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a distance detection device for tracking a preceding vehicle according to an embodiment of the present invention, and FIGS. 2 and 3 show an image of a preceding vehicle displayed on a display, and then moved within the window. FIG. 4 is a diagram of an image area to be compared with a reference image within the window, and FIG. 5 is a configuration diagram of a conventional distance detection device. 1.2...Lens, 3.4...Image sensor, 5.
・Destination (te wheel, 6, 7...Analog-digital converter,
8.9...Memory, 10...Microcomputer, 11...Display, 12...Window forming device, 13...Image tracking instruction switch, 14...Window. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] An image sensor that captures an image of a preceding vehicle, a display unit that displays an image captured by the image sensor, an image tracking window that is displayed in advance at a predetermined position on the display unit, and an image tracking that can be operated by the driver. an instruction switch;
When the image of the preceding vehicle enters the image tracking window, an image tracking means image-tracks the image of the preceding vehicle by operating the image tracking instruction switch; 1. An inter-vehicle distance detection device for tracking a preceding vehicle, comprising: a detection means for detecting an inter-vehicle distance.