JPH0855295A - Vehicle detecting device - Google Patents

Abstract

PURPOSE:To provide the vehicle detecting device which can accurately detect the position and width of a vehicle even when the vehicle is small like a motor bicycle. CONSTITUTION:A gantry 2 is provided over a road surface 1 having plural lanes in the lane width direction, and plural line sensors 3a, 3b... are installed on the gantry 2 in the centers of the lanes 4a-4c and on the border lines of the lanes. In this case, the visual fields 3x of the line sensors 3a, 3b... are set to larger than the lane width and made to overlap with one another in the centers of the lanes and at border line parts, and the visual fields of 2nd neighboring line sensors overlap with one another in the lane centers and at border line parts nearly by motor bicycle width. Then signals outputted from the line sensors 3a, 3b... are logically processed by a signal processor to measure the position and width of the passing vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle detection device for optically detecting a vehicle traveling in multiple lanes.

[0002]

2. Description of the Related Art When automating a toll collection operation at a toll gate on a toll road, it is necessary to automatically detect a vehicle entering or passing through. As a vehicle detection device for this purpose, conventionally, there is a device using an optical method as shown in FIG. That is, a gantry 2 is provided above the road surface 1 on which the vehicle travels and in the lane width direction, and a plurality of line sensors 3a, 3b, ... Are arranged on the gantry 2 to image the road surface 1 immediately below. In this case, the line sensor 3
are arranged at the center of the lanes 4a, 4b, ... And on the boundary line, and the fields of view 3x are overlapped by 1/2.

Then, the state of the road surface 1 when the vehicle has not entered is imaged by the line sensors 3a, 3b, ... And stored as a reference signal, and then each lane 4a,
The vehicle is detected by performing comparison processing with the signals imaged by the line sensor in the center of 4b, ... And the line sensors on both sides thereof. For example, as shown in FIG. 5, the second lane 4
In b, the signals captured by the line sensor 3d at the center of the lane and the line sensors 3c and 3e on both sides of the lane are compared with the reference signal, and the vehicle 5 is detected from the change in the signal. In FIG. 5, S1 is a signal change of the line sensor 3c, S2 is a signal change of the line sensor 3e, and S3 is a signal change of the line sensor 3d. When the vehicle 5 passes directly below the line sensor 3d, the line sensor 3d captures an image of the vehicle 5 from directly above, so that the signal change S3 becomes larger than the actual width of the vehicle 5. Also, the line sensor 3
The signals c and 3e overlap the field of view 3x of the line sensor 3d by ½ from the side and image the vehicle 5, so that the signal changes S1 and S2 are approximately 1 of the vehicle width, respectively.
/ 2. Therefore, the vehicle width 6 of the vehicle 5 can be detected by taking the logical product of the signal changes S1 and S2 and the signal change S3.

[0004]

In the case of the vehicle 5 having the normal vehicle width as described above, the vehicle width 6 is accurately determined by logically calculating the signal changes S1, S2 and S3 obtained by the line sensor. Can be detected. Further, even if the motorcycle has a narrow vehicle width, the vehicle width can be accurately detected unless it is directly under the line sensors 3a, 3b, ....

However, in the above-mentioned conventional method, when the motorcycle 5a having a narrow vehicle width travels in the center of the lane 4b, that is, near the limit of the field of view 3x of the line sensors 3c and 3e, as shown in FIG. Signal change S3 by the sensor 3d
Is large, but the line sensor 3c, 3e allows the bike 5a
Since the signal change width 7 for detecting is small, the signal changes S1 and S2 are very small. As a result, the vehicle width 6 obtained by processing the signal is smaller than the actual vehicle width.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle detection device capable of accurately detecting the position and width of a vehicle even in a small vehicle such as a motorcycle. .

[0007]

A vehicle detection device according to the present invention includes a gantry provided above a road having a plurality of lanes and in the lane width direction, and a boundary between the center of each lane and the lane with respect to the gantry. A plurality of line sensors provided so as to be located on a line, and the field of view of each line sensor is set to be equal to or larger than the lane width so that they overlap each other at the lane center and at the boundary line. It is characterized in that it is provided with a setting means for setting so as to overlap the width of the motorcycle at the center or the boundary line portion, and a signal processing device for detecting a passing vehicle based on a detection signal from the line sensor.

[0008]

Each line sensor takes an image of the road surface of each lane and outputs it to the signal processing device. This signal processing device determines the presence or absence of a vehicle by detecting a change in the signal output from the line sensor. At this time, the field of view of each line sensor should be equal to or larger than the lane width, and the field of view of one line sensor away from the line sensor should overlap with the center of the lane or the boundary to capture the image of the road surface. Even if the vehicle of (1) runs near the center or near the boundary of the lane, the change width of the signal output from the line sensor located diagonally above can be widened. Therefore, the position and width of the passing vehicle can be accurately obtained by logically processing the signals output from the line sensor immediately above the vehicle and the line sensor located diagonally above.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a state where a plurality of, for example, seven line sensors 3a, 3b, ... Are attached to the gantry 2 on a three-lane road having the first, second, and third lanes 4a to 4c. The gantry 2 is provided above the road surface 1 and in the lane width direction, and has line sensors 3a, 3b, ...
Are held at the center and boundary positions of the lanes 4a to 4c. The line sensors 3a, 3b ...
The width is 4c or more, and the fields of view 3x are set to overlap at the center of the lane and at the boundary, respectively, and the field of view 3x of one line sensor away from each other is about the bike width at the center of the lane or at the boundary. To do. Therefore,
Line sensor 3 arranged in the center of each lane 4a-4c
In b, 3d, and 3f, the field of view 3x overlaps the width of the motorcycle at the boundary 11 of the lanes 4a to 4c, and the lanes 4a to 4c.
Line sensors 3a, 3c, 3 arranged at the boundary of the
In e and 3g, the field of view 3x overlaps the width of the motorcycle at the center 12 of each lane 4a to 4c. Reference numeral 13 indicates a portion where the visual fields 3x of the line sensors 3a, 3b, ...

The line sensors 3a, 3b, ...
The video signal picked up by is sent to the signal processing device 20 and processed as shown in FIG. This signal processing device 2
0 is composed of a signal processing unit 21 and a CPU 22. In the signal processing unit 21, the state of the road surface 1 when the vehicle is not entering is imaged by the line sensors 3a, 3b, ... And stored as a reference signal. After that, the signal processing unit 21 converts the video signals sent from the line sensors 3a, 3b, ... into digital signals, compares them with a reference signal stored in advance, and determines the presence / absence of a vehicle based on a change in the signals. And outputs it to the CPU 22. CPU22,
The position, width, etc. of the traveling vehicle are calculated based on the signal processed by the signal processing unit 21.

Next, the operation of the above embodiment will be described. As shown in FIG. 3, for example, when the motorcycle 5a runs in the center of the second lane 4b and enters the field of view 3x of the line sensors 3c to 3e, the width of the motorcycle 5a is increased by the line sensor 3d installed right above the line sensor 3c. A wider signal change S3 is obtained.
Further, the signal changes S1 and S2 are obtained by the line sensors 3c and 3e arranged on the side of the line sensor 3d. In this case, the line sensors 3c and 3e are connected to the second lane 4
At the center of b, the field of view 3x overlaps the width of the bike, so that a large signal change width 7 is obtained as compared with the conventional device, and therefore the signal changes S1 and S2 are also large. That is, the field of view of the motorcycle 5a by the line sensor 3c is wide on the right side in the figure, and the signal change S1
Is widened so that the right side substantially matches the right side of the motorcycle 5a. Further, the field of view of the motorcycle 5a by the line sensor 3e is wide on the left side in the drawing, and the signal change S2 thereof is wide so that the left side substantially matches the left side of the motorcycle 5a.

Therefore, in the signal processing device 20 of FIG. 2, the logical sum of the signal changes S1 and S2 of the line sensors 3c and 3e is calculated, and the result and the signal change S of the line sensor 3d are obtained.
By taking the logical product of 3 and 3, the accurate vehicle width 6 and vehicle position of the motorcycle 5a can be measured.

Further, the motorcycle 5a has the respective lanes 4a, 4b, 4
Even when traveling on the boundary 11 of c, the vehicle width 6 and the vehicle position can be accurately measured in the same manner as when traveling in the center of the lane.

When a vehicle having a wide vehicle width travels, for example, in the center of the lane 4b, the signal changes S1 and S2 by the line sensors 3c and 3e are wider than in the conventional device shown in FIG. An accurate vehicle width 6 can be obtained by taking a logical product with the signal change S3 due to 3d.

As described above, the line sensors 3a, 3b, ...
By enlarging the field of view and providing an overlapping part, even if a small vehicle such as a motorcycle runs near the center or the boundary of the lane, the signal change of two or more line sensors on both sides is processed. The vehicle position and vehicle width can be measured.

[0016]

As described above in detail, according to the present invention, the field of view of each line sensor is expanded, and the road surface is imaged by overlapping at the center and the boundary of the lane to signal the signal change due to the running of the vehicle. Since the vehicle is processed by the processing device to detect the vehicle, the presence or absence of the vehicle can be reliably detected even when a small vehicle such as a motorcycle runs near the center or the boundary of the lane, and the vehicle position and the vehicle position can be detected. It is possible to accurately measure the width and the like.

[Brief description of drawings]

FIG. 1 is a diagram showing a line sensor attached state of a vehicle detection device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration in the embodiment.

FIG. 3 is a diagram for explaining a vehicle detection operation in the embodiment.

FIG. 4 is a diagram showing a state in which a line sensor of a conventional vehicle detection device is attached.

FIG. 5 is a diagram for explaining a vehicle detection operation of a conventional vehicle detection device.

FIG. 6 is a diagram for explaining a motorcycle detection operation of a conventional vehicle detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Road surface 2 Gantry 3a, 3b, ... Line sensor 4a-4c Lane 5 Vehicle 5a Bike 6 Vehicle width 7 Signal change width 11 Lane boundary 12 Lane center 13 Field of view overlap section 20 Signal processing device 21 Signal processing section 22 CPU

Claims (1)

[Claims] 1. A gantry provided above a road having a plurality of lanes and in a lane width direction, and a plurality of line sensors provided so as to be located at the center of each lane and on the boundary line between the lanes with respect to the gantry. The line-of-sight of each line sensor should be equal to or larger than the lane width so that they overlap each other at the center of the lane and at the boundary. And a signal processing device for detecting a passing vehicle based on a detection signal from the line sensor.