JPH03231111A - Apparatus for detecting distance between vehicles in order to follow preceding vehicle - Google Patents

Abstract

PURPOSE:To minimize the effects of other bodies around a preceding vehicle and to stabilize the tracking of an image by preparing windows in plural kinds of similar shapes corresponding to the preceding vehicles beforehand, and by a driver selecting one window in response to the kind of preceding vehicle. CONSTITUTION:A computer 10 reads an image signal in a window 17 out of a memory 9 and uses the signal as a reference image signal for operating the distance between vehicles. A region corresponding to the window 17 in a memory 8 wherein the image signals of an image sensor 3 are stored is selected with the computer 10. Every one picture element of the image signal from the memory 8 is sequentially shifted with respect to the reference image signal, and the total sum of the absolute values of the differences between the signals for every right and left picture elements is operated. Then, the right and left picture elements are compared. The shifted amount 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 base- line length of an optical system is made to be L. The focal distances of lens 1 and 2 are made to be (f). A distance to the preceding vehicle 5 is made to be R. Then, the distance R can be obtained by R=f.L/nP.

Description

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

[Conventional technology]

Conventionally, optical distance detecting 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. 6, and these left and right optical systems are arranged apart by the base line length and are composed of lenses 1 and 2. A separate image sensor 3 is provided at the focal length f of the lens 1.2.
4 is provided, and the image sensor 3 is provided in the signal processing device 20.
．． The image signals of 4 are electrically superimposed while being shifted sequentially, and the distance R to the object 21-L is determined by the principle of triangulation from the shift amount β when the two image signals match best. I'm looking for closure.

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 influence of other surrounding objects can be minimized by allowing the operator to specify and modify the target to be tracked on the display screen and the Ilf-shaped tail gate (window) while looking at the display screen. I try to do that.

[Problem to be solved by the invention]

The inter-vehicle distance detecting device is configured to continuously detect the inter-vehicle distance to the preceding vehicle to be followed by combining the optical distance detecting device using the above-mentioned image sensor and the preceding vehicle image tracking device. As disclosed in Publication No. 60-33352, it is almost impossible for a driver to create an image of the preceding vehicle and a window (tracking gate) with an R-like shape while driving the vehicle using a joystick, track pole, mouse, etc. It is possible.

This invention was made in order to solve the above-mentioned problems, and it is possible to easily change the R-like shape of the vehicle in front while driving! ii) An object of the present invention is to provide an inter-vehicle distance detection device for tracking a preceding vehicle that can set an image tracking window and also allows the user to know which preceding vehicle is being followed by the own vehicle even when multiple preceding vehicles are running. shall be.

[Means for Solving the Problems] An inter-vehicle distance detection device for tracking a preceding vehicle according to the present invention includes an image sensor that captures an image of a preceding vehicle, and an image tracking window having a plurality of preset shapes surrounding the image of the preceding vehicle. a selection means for the driver to select one of the image tracking windows according to the type of the preceding vehicle; and a detection means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle displayed within the window. It is characterized by having the following.

[For production]

In this invention, the image tracking window is set in a shape corresponding to the type of preceding vehicle, for example, a passenger car, light vehicle, truck, or two-wheeled vehicle, and the preceding vehicle to be followed is, for example, a truck. If so, the driver selects the truck window so that the image of the specified preceding vehicle can be tracked using the window that has a similar shape to the image of the preceding vehicle.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows a configuration diagram of the inter-vehicle distance detecting device for tracking a preceding vehicle according to the present invention. In the figure, 1 and 2 are lenses forming left and right optical systems, and 3 and 4 are arranged corresponding to these lenses 1 and 2, respectively. A two-dimensional image sensor is installed, 5 is a preceding vehicle to be followed, and 6.7 is an analog sensor for converting the analog signal from the image sensor 3.4 into a digital signal.
a digital converter; 8.9 is a memory for storing image signals from the image sensors 3 and 4; IO is a microcomputer;
11 is a display that displays an image taken by the image sensor 4 on the right side, and a microcomputer 1
Controlled by 0.

Reference numeral 12 denotes a window setting device 1, in which windows exclusively for trucks, passenger cars, light vehicles, and two-wheeled vehicles are preliminarily set in accordance with the type H of the anticipated preceding vehicle.
3.14.15.16 is the window size selected by the driver by operating the window selection device in which the driver selects one of the windows set above according to the v@ type of the preceding vehicle. , and the designation of images within the window can be set while looking at the display 11.

For example, if an image of a passenger car appears as a preceding vehicle to be followed in the image of the image sensor 4 on the right side and is displayed on the display 11 as shown in FIG. Then, a window 17 exclusively for a passenger car, which is roughly set on the image of the preceding vehicle, is formed. If the preceding vehicle is a truck, the trunk window selection device 13 is operated to form a truck-specific window 18 as shown in FIG. Similarly, if the preceding vehicle is a two-wheeled vehicle, the two-wheeled vehicle window selection device 16 is operated to form a two-wheeled vehicle window 19 as shown in FIG. When such a window is formed, an image signal within the window frame is read into the computer 10, and image tracking of the preceding vehicle is started. This image tracking effect was developed in the Tokuko Sho 6
Publication No. 0-33352 or Special Publication No. 1-35305
This device is similar to the conventional device disclosed in the above publication.

Next, a method for detecting the inter-vehicle distance between the own troops and the preceding vehicle will be explained using an example in which the preceding vehicle is a passenger car as shown in FIG. First, the microcomputer 10 reads out the pixel signals within the window 17 from the memory 9 and uses them as reference image signals for the actual distance between vehicles.

Then, the microcomputer 10 selects an area corresponding to the window 17 in the memory 8 in which the image signal of the left image sensor 3 is stored, and converts the image signal of the memory 8 into one pixel with respect to the reference image signal. While gradually softening, calculate the sum of the absolute values of the signal differences for each left and right pixel by 6.
I will do 4X. That is, the digit 1 of the picture that most matches the picture within the window 17 is determined by sequentially shifting one pixel at a time. At this time, as shown in FIG. 5, the region involved in the calculation corresponds to the region 20 of the image in the memory 8 with respect to the reference image signal in the window 17.

Compare the left and right pixels as described above, and let the shift amount of the pixel when the sum of the absolute values of the difference signals becomes the minimum be n pixels, the pixel pitch be P, the base line length of the optical system be L, and the lens 1.2's focal length is r, and the distance to the preceding vehicle 5 is R, R is determined by the following equation.

R=f' and P In this way, even if the preceding vehicle 5 moves to the left or right, it will be tracked and the inter-vehicle distance between the own vehicle and the preceding vehicle will be continuously determined. be able to.

〔Effect of the invention〕

As explained above, according to the present invention, multiple types of windows with similar shapes corresponding to the preceding vehicle are prepared in advance, and the driver selects one of the windows according to the type of the preceding vehicle. Therefore, a window with a similar shape to that of the preceding vehicle can be easily set while driving the own vehicle, thereby minimizing the influence of other objects around the preceding vehicle and stably performing image tracking. 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 driving, the driver can accurately determine the distance between the vehicle and the preceding vehicle that it is following. can always be detected.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an inter-vehicle distance detection device for tracking a preceding vehicle according to an embodiment of the present invention, FIGS. 2 to 4 are display diagrams of image tracking windows set according to the type of preceding vehicle, and FIG. FIG. 5 is a diagram of an image area to be compared with a reference image within a window, and FIG. 6 is a configuration diagram of a conventional distance detection device. 1.2...Lens, 3.4...Image sensor, 5.
... Leading vehicle, 6.7... Analog-to-digital converter,
8.9...Memory, 10...Microcomputer, 11...Display, 12...Window setting device, 13-16...Window selection device, 17-19.
...wind. 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 the preceding vehicle; an image tracking window that surrounds the image of the preceding vehicle and has a plurality of preset shapes;
A selection means for the driver to select one of the image tracking windows according to the type of the preceding vehicle, and a detection means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle displayed in the window. An inter-vehicle distance detection device for tracking a preceding vehicle, characterized by: