JPS6233640B2 - - Google Patents

Description

[Detailed Description of the Invention] Background of the Invention The present invention detects trends in temporal changes in information regarding congestion of vehicles traveling on roads, particularly trends in congestion at locations where signal lights are installed such as intersections. Regarding equipment.

At intersections and other locations where signal lights are installed, vehicle traffic congestion changes depending on the signal status. For example, when the traffic light turns red, the length of the traffic jam becomes longer, and when the traffic light turns green and vehicles begin to flow, the length of the traffic jam becomes shorter. Therefore, when trying to understand traffic congestion trends over a much longer time range than the signal cycle of a traffic signal, such as an increase or decrease in traffic jam length, it is necessary to must be eliminated.

Figure 1 shows the variation in traffic jam length at the locations where signal lights are installed. The graph showing the traffic jam length is
It is a combination of a component that changes at a period matching the signal period T and a component (indicated by Q) that changes much more slowly than this. This slowly changing component Q indicates the tendency of road congestion from a macroscopic perspective.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device that accurately detects trends in traffic congestion that are not affected by the appearance of traffic lights, among the fluctuation trends in traffic congestion information at locations where traffic light devices are installed.

The vehicle congestion detection device according to the present invention includes a signal period synchronization signal generating means for outputting a synchronization signal synchronized with the signal period of a signal lamp installed on a road, and a signal period synchronization signal generating means installed near the signal lamp, which detects a signal synchronized with the signal period of a signal lamp installed on the road. A traffic jam detection means for collecting information on traffic jams, and a signal indicating information on traffic jams from the traffic jam detection means is sampled using the synchronization signal,
The present invention is characterized by comprising a congestion tendency detection means for detecting congestion tendency by comparing with the previous sampling value.

According to this invention, since the signal representing the vehicle congestion information detected near the signal lamp is sampled with a signal synchronized with the signal cycle of the signal lamp, it is possible to eliminate fluctuations in the traffic congestion information due to the display of the signal lamp. By comparing these sampled values, it is possible to accurately detect trends in vehicle congestion that are not affected by signal light display.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 2, a pillar 6 is erected near the location where the signal lamp 5 is installed, and a vehicle congestion detection device 7 is attached to the upper end of the pillar 6. With reference to FIG. 3, vehicle congestion detection device 7
includes an optical system 1, this optical system 1 has a convex lens 2, and an imaging plane 3 is set so as to capture a vehicle image behind the position of this optical system 1 in the direction of travel of the vehicle (arrow X). has been done. On this image forming surface 3, a large number of light receiving elements 11, 12,
..., 1n are arranged in a straight line. The light receiving elements 11 to 1n are composed of, for example, photo diodes. The detection surfaces 21, 22, ..., 2n indicate the range on the road surface that is detected by each of the light receiving elements 11 to 1n, and is a certain distance (for example, 20
They are set at intervals of ~50m). The locations of each of the detection surfaces 21 to 2n are detection points, and the range Y including all of the detection surfaces 21 to 2n is the detection range.

FIG. 4 shows a block diagram of the vehicle congestion detection device 7.
FIG. 5 shows the output waveforms of each block of the circuit of FIG. 4, respectively. In these figures, output image signals A1, A2, . . . of each light receiving element 11 to 1n are shown.
...An is amplified to an appropriate size by preamplifiers 31, 32, ...3n, and then comparators 41,
42, . . . 4n, respectively. Comparator 41
~4n has a standard level set,
The output signals of each of the amplifiers 31 to 3n are discriminated based on this reference level, and thereby their waveforms are shaped. The time widths of the waveform-shaped outputs of the comparators 41 to 4n are measured by detection time counters 51, 52, . . . 5n. As shown in Fig. 6, the vehicle receives light from the time it enters the detection range R of the light receiving element (this vehicle is indicated by Ca) until the time it exits the range R (this vehicle is indicated by Cb). detected by the element. The length in the direction of the road on the detection surface is the detection length S, and the vehicle length is LC, and the time the vehicle travels this distance (S + LC) is the vehicle detection time.
They are measured by counters 51 to 5n, respectively.
The signals representing the vehicle detection time measured by the counters 51 to 5n are respectively sent to the point congestion determination device 6.
1, 62, . . . 6n, where it is compared with a reference time t0 preset in the traffic jam determination reference time setting device 60. The determiners 61 to 6n output the "H" level signal B1 when the detection time represented by the signals from the counters 51 to 5n is longer than the reference time to.
B2, . . . , Bn are output and held at the “H” level until a signal whose detection time is shorter than the reference time t0 is input. These signals B1 to Bn are sent to the traffic congestion information generator 70. The generator 70 generates signals B1~
It generates various traffic jam information based on the combination of Bn, and is composed of, for example, a logic circuit or a microprocessor. One type of traffic jam information is traffic length. This traffic jam length is signal B
It is expressed by the product of the number of detection points that are at the "H" level among 1 to Bn and the distance between the detection points. In this embodiment, the length of the traffic jam is used as the traffic jam information, and the signals B1 to Bn are added by the generator 70 to become the signal D. This traffic jam length signal D is sent to the output terminal, and is also sent to the signal synchronized traffic jam level detector 71.
Enter.

On the other hand, the vehicle congestion detection device 7 is equipped with a signal detector 81 that detects the signal period of the signal lamp device 5. This signal detector 81 consists of a light receiving element that receives light from a red, blue, or yellow signal lamp of the signal lamp device 5. The output signal of the detector 81 is amplified by a preamplifier 82 and then waveform-shaped by a comparator 83. The output of comparator 83 is sent to signal period synchronization signal generator 84 . This generator 84 detects the rise or fall of the output of the comparator 83 and generates a pulse-like synchronization signal C. The detector 81 detects the lighting of one of the signal lamps of the signal lamp device 5, and the generator 84 detects the time when this signal lamp lights up or goes out, so the period of the synchronization signal C is equal to the signal lamp. It matches the signal period of device 5. This synchronization signal C is sent to a traffic congestion degree detector 71 and a traffic congestion tendency determiner 72.

The congestion degree detector 71 detects the degree of increase or decrease in the length of the traffic jam, samples the signal D representing the length of the traffic jam at the time of inputting the synchronization signal C, and compares the magnitude of the signal D at that time with the previous one. Comparing the magnitude of the signal D at the time of sampling, if it has increased, a signal that is one level larger is output, and if it has decreased, a signal that is one level smaller is output. Therefore, the output signal E of the detector 71 indicates the sum of the number of increases or decreases in the signal D detected every cycle of the signal lamp device 5 (an increase is considered positive and a decrease is considered negative). The traffic jam trend determiner 72 detects a tendency of increase or decrease in traffic jam length, and
Sample the output signal E at the input point of the synchronization signal C, compare the magnitude of the signal E at that time with the magnitude of the signal E at the previous sampling time, and if it increases, select the "H" level signal. , it outputs an "L" level signal if it has decreased. Therefore, the output signal F of the determiner 72 indicates whether the traffic jam length is increasing or decreasing. Since the detector 71 and the determiner 72 perform sampling in synchronization with the signal period of the signal light device 5, these output signals E,
F does not include a component that fluctuates in synchronization with the signal cycle, and the macroscopic degree and tendency of variation in traffic congestion length that is unrelated to the signal cycle of the signal lamp device 5 is detected or determined. These signals E and F are sent to their respective output terminals. Note that the signal E is set to increase or decrease by 1 unit (1 level) for each synchronizing signal C regardless of the amount of increase or decrease in the length of the traffic jam, but the detector 71 detects an amount proportional to the length of the traffic jam, that is, as shown in FIG. Alternatively, the amount indicated by the dashed line Q may be detected.

[Brief explanation of the drawing]

Figure 1 is a graph showing the relationship between traffic congestion length and signal cycle, Figure 2 is a side view showing the road conditions at locations where signal lights are installed and the arrangement of vehicle congestion detection devices, and Figure 3 is vehicle traffic detection. Figure 4 is a diagram showing the schematic arrangement of the optical system included in the device and the light-receiving elements constituting the optical system, as well as the detection surface and detection range of the light-receiving elements; Figure 4 is a block diagram showing the electrical configuration of the vehicle congestion detection device; , FIG. 5 is a waveform diagram showing the output waveform of the circuit shown in FIG. 4, and FIG. 6 is a diagram showing the state of vehicle detection. 1...Optical system, 4...Road, 5...Signal lamp,
7...Vehicle traffic congestion detection device, 11-1n...Light receiving element, 51-5n...Detection time counter, 60...Congestion judgment reference time setting device, 61-6n...Point congestion determination device, 70...Congestion Information generator, 71...Signal synchronized congestion level detector, 72...Congestion trend determiner, 8
1...Signal detector, 84...Signal period synchronization signal generator.

Claims (1)

[Claims] 1. Signal cycle synchronization signal generation means 81, 82, 83, 84 for outputting a synchronization signal C synchronized with the signal cycle of the signal lamp 5 installed on the road, installed near the signal lamp 5. , traffic jam detection means 11 to 1n, 51 to 5n, 60, 61 to 6, which collect information regarding traffic jams of vehicles traveling on roads.
n, 70, and congestion tendency detection means 71, 72 for sampling the signal D indicating information regarding congestion from the congestion detection means with the synchronization signal and detecting the congestion tendency by comparing it with the previous sampling value; A vehicle congestion detection device consisting of. 2 The information regarding the traffic jam is the length of the traffic jam.
A vehicle congestion detection device according to claim 1. 3. The congestion detection means sets a plurality of detection points over a detection range Y of the required length of the road, and collects information regarding vehicle congestion throughout the detection range based on the congestion situation at each of these detection points. an optical system 1 including a plurality of light-receiving elements 11 to 1n arranged at a position overlooking the detection range and detecting vehicles at the plurality of detection points, respectively; and a duration time of the output of each of the light-receiving elements. Detection time counters 51 to 5n that measure the detection time counters, point congestion determination devices 61 to 6n that compare the output of the detection time counters with the required reference time to, and point congestion determination devices 61 to 6n that measure the entire detection range based on the output of the point congestion determination devices. The vehicle traffic congestion detection device according to claim 1, comprising a traffic congestion information generator 70 that generates traffic congestion information.