JPH02196399A - Sudden accident detector - Google Patents

Abstract

PURPOSE:To prevent a large traffic jam by comparing the volume of traffic measured by using a vehicle sensor, and the volume of traffic which can be processed of a stationary bottleneck spot of its downstream, and estimating the generation of a sudden traffic fault generated between them. CONSTITUTION:The passing traffic volume (cycle synchronous traffic volume) and the occupancy rate (cycle synchronous occupancy rate) of one cycle length extending from a blue display start to a blue display start of the next cycle in the vehicle detector 2 installing direction of a signal of an intersection 1 are measured by using the vehicle sensor 2. By multiplying the blue display time in the vehicle sensor 2 installing direction by a saturation traffic flow rate of an inflow path, the traffic volume which can be processed in one cycle is derived, and the cycle synchronous traffic volume of the vehicle sensor 2 is compared with the traffic volume which can be processed, and whether it is below a prescribed ratio alpha (set value) or not is decided. Subsequently, whether each condition is satisfied continuously (n) times (n can be set and about 1 - 3) or not checked up, and it is decided that a sudden event is generated between a stop line of a signal intersection 1 and the vehicle sensor 2 of its upstream. In such a way, a large traffic jam can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an unexpected event detection device used for detecting unexpected events such as traffic accidents and illegal parking on flat streets.

Prior Art Conventional unexpected event detection devices differ depending on whether they are used on flat streets or expressways, and the following methods have been common.

First, in the case of flat streets, important intersections are considered as one link, and the speed and occupancy rate measured by multiple vehicle detectors installed on that link are compared with the corresponding judgment value, and a four-stage Traffic congestion was determined, and the congestion status of each link was displayed on the central map board with lamps, and the status was monitored by the operator. Based on their own experience, operators assumed that some kind of traffic disturbance had occurred if the displayed content was different from normal.

Second, in the case of expressways, the speed and traffic volume measured by vehicle detectors placed at fixed (for example, IKm) intervals are significantly different from those measured upstream or downstream. In some cases, it was assumed that some kind of sudden event had occurred during that time.

Problems to be Solved by the Invention However, in the first conventional unexpected event detection method, in order to compare and judge the congestion status displayed on the central map board and the normal congestion status that the operator remembers, There is a delay of 15 to 30 minutes until an event is detected, and it is not known until a fairly large change in status occurs. There was a problem with it being bad. However, the second conventional incident detection method cannot be applied to flat streets because there are many signalized intersections on flat streets.

The present invention solves these conventional problems,
The purpose of the present invention is to provide an excellent unexpected event detection device that can instantly and accurately detect the occurrence of unexpected events such as traffic accidents and illegal parking even on flat streets with dense intersections using vehicle detectors. That is.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention aims to solve the problem by providing a solution to the problem at 150 to 2 points upstream of a regular bottleneck point such as a signalized intersection on a flat street.
A vehicle detector is installed at the 00m point to continuously measure the amount of traffic passing by during a certain period of time, and on the condition that the traffic queue length has reached the vehicle sensor, the measured traffic volume is determined within the specified period of time. If the amount of traffic that can pass through the regular bottleneck point (hereinafter referred to as manageable traffic volume) is significantly lower than the amount of traffic that can pass through the regular bottleneck point, there is some kind of traffic obstruction or event between the regular bottleneck point and the vehicle sensor. It is determined that an unexpected event has occurred. However, if a jam has already occurred downstream of the steady bottleneck point, it is determined that no sudden event has occurred in that section. Note that the above-mentioned manageable traffic volume is obtained by multiplying the total value of the constant bottleneck time at a signalized intersection by the saturation traffic flow rate. The vehicle sensor measures the traffic flow in synchronization with the signal cycle length of the traffic signal located downstream or upstream, and determines the presence or absence of a traffic obstruction for each cycle, and measures it continuously at least n times (n is 1 or more). ) The system is configured to determine that an unexpected event has occurred when it is determined that the above-mentioned traffic obstruction has occurred.

Therefore, according to the present invention, the traffic volume measured using vehicle detectors already installed in the existing urban traffic control system is compared with the traffic volume that can be handled at a regular bottleneck point downstream thereof. This makes it possible to quickly and accurately estimate the occurrence of sudden traffic disturbances that occur during that time, and to take countermeasures such as signal control or obstacle removal based on this information, making it possible to prevent major traffic jams. It has the effect of being able to.

Embodiment FIG. 1 shows the structure of an embodiment of the present invention. 1st
In the figure, 1 is a signalized intersection that is a regular bottleneck point, 2 is a vehicle detector located 150 to 200 meters upstream from the stop line 6 of signalized intersection 1, and 3 is installed on the outflow side of signalized intersection 1. This is a vehicle sensor. 4 means for detecting the signal display timing of the intersection 1;
5 is a means for measuring traffic volume using the vehicle sensor 2;
6 is the saturation traffic flow rate in the installation direction of the vehicle sensor 2 of the traffic light. 7 is a means for determining the manageable traffic volume from the signal green display time in the installation direction of the vehicle sensor 2 determined by the detection means 4 and the saturated traffic flow rate. Reference numeral 8 denotes a means for determining whether or not the traffic jam queue has reached the vehicle sensor 2. Reference numeral 9 represents a means for determining whether a traffic jam has occurred at the signalized intersection 1 from downstream. 10 is a means for estimating whether or not a traffic obstacle has occurred between the signalized intersection] and the vehicle sensor 2, and 11 is an output means thereof.

Next, the operation of the above embodiment will be explained. In Fig. 2, in step 12, the passing traffic volume (cycle synchronous traffic volume) for one cycle length from the start of the blue display in the installation direction of the vehicle detector 2 of the traffic light at the intersection 1 to the start of the blue display of the next cycle is calculated. The occupancy rate (cycle synchronized occupancy rate) is measured using the vehicle sensor 2. Proceed to Step 7 - The knob 13 determines from the cycle synchronization occupancy rate whether or not the congestion queue has reached the position of the vehicle sensor 2.
In step 14, it is determined whether there is a blockage based on the cycle synchronized occupancy rate measured by the vehicle sensor 3 and the traffic volume. In step 15, the traffic volume that can be handled in one cycle is calculated by multiplying the blue display time of the vehicle sensor 2 installed force direction by the saturated traffic flow rate of the same inflow road.In step 16, the cycle-synchronous traffic volume of the vehicle sensor 2 is calculated. It is determined whether the traffic volume is below a certain ratio α (set value) by comparing it with the above-mentioned manageable traffic volume. In step 17, it is checked whether each of the conditions in steps 13, 14 and 16 are satisfied n times in a row (n is configurable and approximately 1 to 3), and in step 18, the stop line of signalized intersection 1 and the vehicle detector 2 upstream thereof are It is determined that some kind of traffic disturbance or unexpected event has occurred during that period, and the result is output.

In some cases, the first detection sensor 3 may also be used as the downstream link sudden event detection sensor 2, and the saturated traffic flow rate may be achieved by installing the vehicle sensor near the stop line. It is clear that the accuracy will improve if you actually measure it.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

(1) Even on flat streets with dense intersections, unexpected events such as traffic accidents and illegal parking can be detected immediately and accurately using vehicle detectors, and signal control and It becomes possible to take countermeasures to remove obstacles and prevent major traffic jams.

(2) The vehicle detector used can be used for signal control button selection and traffic jam display, which are already installed in many current traffic control systems, so it is very practical.
It is also economical.

[Brief explanation of the drawing]

FIG. 1 is a schematic functional block diagram of an unexpected event detection device according to an embodiment of the present invention, and FIG. 2 is a processing flowchart of the device. 1. Signalized intersection, 2. Vehicle detector for detecting unexpected events,
3-・Vehicle sensor for first detection, 4・Traffic light 9/ Display timing detection means, 5... Passing traffic flow measuring means, 6... Saturation traffic flow rate file, 7... Processable Traffic volume calculation means, 8.--Congestion matrix existence detection means, 9. First υ detection means, 10. Traffic obstruction occurrence estimation means, 11. Output means.

Claims (3)

[Claims] (1) Regularly compare the maximum traffic volume that can pass through the bottleneck point of the traffic light installed on the road with the traffic volume measured by the vehicle sensor installed upstream, and calculate the length of the traffic queue up to the vehicle sensor. An unexpected event detection device is characterized in that it is determined that a traffic disturbance has occurred when the difference between the two reaches a determination value. (2) Traffic volume measurement using a vehicle sensor is performed in synchronization with the signal cycle length of a traffic signal located downstream or upstream, and the presence or absence of a traffic obstruction is determined for each cycle. (above) The unexpected event detection device according to claim 1, wherein the unexpected event is determined to have occurred when it is determined that the above-mentioned failure exists. (3) Claim 1 which detects that a blockage has already occurred from downstream at a bottleneck point such as a signalized intersection, and checks downstream one after another to find the actual point where an unexpected event has occurred. The unexpected event detection device according to item 2.