JP2003022495A - System for monitoring vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a large error in detecting the vehicle speed of a vehicle at a distance from a monitor camera is possibly generated when an abnormal travel of a vehicle is detected from vehicle speed information obtained by a time difference system or a difference image system from a frame image obtained by photographing the vehicle traveling on an expressway by the monitor camera. SOLUTION: When current speed information does not have large variation from last one (S2), the current speed information is used as speed information as it is (S3), but when large variation is generated, the current speed information is used as speed information as it is (S5) on condition that the vehicle is nearby the monitor camera; when the vehicle is not nearby the monitor camera, it is decided whether the brake lamps of the vehicle illuminate and when the brake lamps illuminate, the current speed information is used as speed information as it is (S5), but when not, the last speed information is used as current speed information (S8).

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a system for monitoring a vehicle running on a highway, and more particularly to a system for detecting abnormal running of a vehicle from a captured image of the vehicle. In this type of surveillance system, a surveillance camera is installed on a side wall or an upper portion of a highway, and this photographed image is transmitted to a computer system of a surveillance center. It is used for information acquisition and notification of road congestion status by means of an automatic monitoring function and the like, and also for speeding monitoring of vehicles, particularly for monitoring and notification in a tunnel. One of the monitoring functions of this monitoring system is a function of detecting abnormal running from a photographed image of a vehicle and notifying the operator of it. In this abnormal running detection, the vehicle speed is detected by a time difference method or a difference image method. The time difference method detects a vehicle speed from a time difference between two temporally continuous frame images. [0005] The difference image method detects the vehicle speed of two temporally continuous frame images from the difference in the position of the traveling vehicle with respect to a still partial image of a road facility or the like. [0006] If the vehicle speed is detected by the time difference method or the difference image method, the vehicle running near the surveillance camera has a small error, and the group monitoring (the vehicle running The overall flow) is also effective, but at a position far from the surveillance camera (for example, 80 m from the camera), the amount of movement of the vehicle in the captured image is small, so the error is large, and whether the vehicle speed actually changes or the error It becomes difficult to judge. as a result,
Unable to determine abnormal running for a vehicle far from the surveillance camera. As a countermeasure for this, it is conceivable to provide a large number of surveillance cameras, but the equipment and maintenance costs are enormous. It is an object of the present invention to provide a vehicle monitoring system that reliably and easily detects the speed of a vehicle located far from the monitoring camera. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a case where a change in vehicle speed information based on an image of a distant vehicle periodically obtained by a surveillance camera is large. If it is not due to brake operation, it is determined to be due to a measurement error, and in this case, the previous vehicle speed information is adopted as the current vehicle speed information, thereby eliminating vehicle speed detection due to the error and accurately detecting vehicle speed. It is possible to detect an abnormal running from the vehicle, and is characterized by the following configuration. The vehicle has a function of photographing a vehicle traveling on a highway with a monitoring camera, obtaining vehicle speed information from the photographed frame image by a time difference method or a difference image method, and detecting abnormal running of the vehicle from the vehicle speed information. In a surveillance system, when the speed information of the current time does not change much compared to that of the previous time, the speed information of the current time is adopted as it is as speed information, and when the change is large, the vehicle is located near the monitoring camera. At this time, the current speed information is used as it is as speed information, and if it is not near the surveillance camera, it is determined whether or not the brake lamp of the vehicle is lit, and if the brake lamp is lit, the current speed information is used as it is as speed information. And a means for adopting the previous speed information as the current speed information when the brake lamp is not lit. That. FIG. 1 is a flow chart for detecting a running abnormality of a monitoring system according to an embodiment of the present invention, which is provided as a software configuration mounted on a computer system of a monitoring center. First, speed information of a detection target vehicle is input from an image captured by a monitoring camera (S1). This speed information is obtained from a captured image by a time difference method or a difference image method, as in the related art. Next, by comparing the inputted current speed information with the previous speed information, it is checked whether or not there has been a large change in vehicle speed (S2). When the vehicle speed change is not large, the current speed information is adopted as it is (S3) and output as speed information (S4). When the vehicle speed change is large, it is checked whether or not the position of the vehicle is near the monitoring camera (S5). If the vehicle is in the vicinity of the vehicle, the current speed information is adopted as it is (S3) assuming that the speed information is accurately measured, and is output as speed information (S4). If the position of the vehicle is far from the surveillance camera, the tail of the vehicle is analyzed from the photographed image to determine whether or not the brake lamp is lit (S6). From this determination result, it is checked whether or not the brake lamp is turned on (S7). If the brake light comes on,
Assuming that the vehicle speed change becomes large due to the brake operation of the vehicle, the current speed information is adopted as it is (S3),
Output as speed information (S4). If the brake lamp is not lit, the current vehicle speed information is determined to be a vehicle speed change due to a large error, the previous speed is adopted as the current speed (S8), and output as speed information (S4). Therefore, in this embodiment, when the input speed information changes greatly and the vehicle is located far from the surveillance camera, if the vehicle does not have a brake operation, the current vehicle speed information contains a large error. And adopt the previous vehicle speed information. As a result, appropriate vehicle speed information can be obtained, and abnormal running can be reliably detected. In addition, as for the device configuration, it is only necessary to add a small software configuration while keeping the conventional measurement device configuration. As described above, according to the present invention, when the change in the vehicle speed information based on the photographed image of the vehicle periodically obtained by the monitoring camera is not caused by the operation of the brake, it is caused by the measurement error. In this case, the previous vehicle speed information is adopted as the current vehicle speed information, so that it is possible to reliably and easily detect the vehicle speed of a vehicle far from the surveillance camera.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart for detecting a traveling abnormality of a monitoring system according to an embodiment of the present invention.

Claims (1)

A vehicle traveling on a highway is photographed by a monitoring camera, and vehicle speed information is obtained from the photographed frame image by a time difference method or a difference image method. A monitoring system having a function of detecting traveling, when the current speed information does not have a large change compared to the previous speed information, the current speed information is directly used as speed information, and when the change is large, When the vehicle is near the surveillance camera, the current speed information is used as it is. When the vehicle is not near the surveillance camera, it is determined whether or not the brake lamp of the vehicle is lit. If the brake light is not lit, the previous speed information is used as the current speed information. Vehicle monitoring system comprising the.