JP3192885B2 - Vehicle detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art When toll collection work is automated at a tollgate on a toll road or the like, it is necessary to automatically detect vehicles that enter or pass through. Conventionally, as a vehicle detecting device for this purpose, 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,... In this case, the line sensor 3
a, 3b,... are arranged at the center and on the boundary of each of the lanes 4a, 4b,..., and each field of view 3x overlaps by １ ／.

[0003] The state of the road surface 1 when the vehicle is not approaching is imaged in advance by the line sensors 3a, 3b, ... and stored as a reference signal.
4b,..., The vehicle is detected by performing comparison processing with signals captured by the central line sensor and the line sensors on both sides thereof. For example, as shown in FIG.
In b, the signal captured by the line sensor 3d at the center of the lane and the line sensors 3c and 3e on both sides are compared with a reference signal, and the vehicle 5 is detected from a 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 immediately 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 is larger than the actual width of the vehicle 5. Also, the line sensor 3
Since c and 3e respectively capture the image of the vehicle 5 by overlapping the field of view 3x of the line sensor 3d by か ら from the side, the signal changes S1 and S2 are each approximately 1% of the vehicle width.
/ 2. Therefore, the vehicle width 6 of the vehicle 5 can be detected by calculating 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 can be accurately calculated by logically operating 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 below the line sensors 3a, 3b,.

However, according to the above-mentioned conventional method, as shown in FIG. 6, when the narrow motorcycle 5a runs 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, the line Signal change S3 by sensor 3d
Is large, but the motorcycle 5a is
Is small, the signal changes S1 and S2 are very small. As a result, there is a problem that the vehicle width 6 obtained by processing the signal becomes smaller than the actual vehicle width.

The present invention has been made in view of the above circumstances, and has as its object 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 a lane width direction, and a center of each lane and a boundary between the lanes with respect to the gantry. A plurality of line sensors provided so as to be located on the line, and the field of view of each line sensor is set to be equal to or larger than the lane width so as to overlap at the lane center and the boundary line, respectively, and the line of sight and the lane of the line sensor separated by one. It is characterized by comprising setting means for setting so as to overlap by about the width of the motorcycle at the center or at the boundary, 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 a signal output from a line sensor. At this time, the field of view of each line sensor is set to be equal to or larger than the lane width. Even if the vehicle travels in 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 performing logical operation processing on 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 a gantry 2 on a three-lane road having 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,.
At the center and boundary positions of each of the lanes 4a to 4c. The line sensors 3a, 3b,...
4c or more, so that each field of view 3x overlaps at the center of the lane and the boundary, respectively, and overlaps with the field of view 3x of the line sensor that is one distance away from the center of the lane or at the boundary about the bike width. I do. Therefore,
Line sensor 3 arranged at the center of each of lanes 4a to 4c
In b, 3d, and 3f, the field of view 3x overlaps the width of the motorcycle at the boundary 11 between the lanes 4a to 4c, and the lanes 4a to 4c
Line sensors 3a, 3c, 3 arranged at the boundary of
As for e and 3g, the visual field 3x overlaps about the motorcycle width at the center 12 of each of the lanes 4a to 4c. Reference numeral 13 denotes a portion where the visual fields 3x of the line sensors 3a, 3b,... Overlap.

The line sensors 3a, 3b,.
Are sent to the signal processing device 20 for processing as shown in FIG. This signal processing device 2
Reference numeral 0 denotes a signal processing unit 21 and a CPU 22. The signal processing unit 21 previously images the state of the road surface 1 when the vehicle does not enter by the line sensors 3a, 3b,... And stores it as a reference signal. The signal processing unit 21 then converts the video signals sent from the line sensors 3a, 3b,... Into digital signals, compares them with reference signals stored in advance, and determines the presence or absence of a vehicle based on a change in the signals. And outputs it to the CPU 22. The CPU 22
The position, the vehicle width, and the like 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 determined by the line sensor 3d installed directly above the motorcycle. A wider signal change S3 is obtained.
Further, 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
At the center of b, the visual field 3x overlaps by the width of the motorcycle, 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 visual field of the line sensor 3c with respect to the motorcycle 5a is wide on the right side in the figure, and its signal change S1
Is widened so that the right side substantially matches the right side of the motorcycle 5a. The field of view of the motorcycle 5a by the line sensor 3e is wide on the left side in the figure, and the signal change S2 is wide so that the left side substantially matches the left side of the motorcycle 5a.

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

The motorcycle 5a is connected to each of the lanes 4a, 4b, 4
Even when the vehicle travels 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 large width travels, for example, in the center of the lane 4b, the signal changes S1 and S2 caused by the line sensors 3c and 3e are wider than those of the conventional device shown in FIG. By taking a logical product with the signal change S3 by 3d, an accurate vehicle width 6 can be obtained.

As described above, the line sensors 3a, 3b,.
By expanding the field of view and providing an overlap portion, even if a small vehicle such as a motorcycle runs in the center of the lane or near the boundary, it processes signal changes of two or more line sensors on both sides. , 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 enlarged, and the road surface is imaged so as to overlap at the center and at the boundary of the lane. Since the processing unit detects the vehicle, the presence or absence of the vehicle can be reliably detected even when a small vehicle such as a motorcycle runs in the center or near the boundary of the lane, and the vehicle position and the vehicle can be detected. The width and the like can be measured accurately.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state where a line sensor is attached to 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 view for explaining a vehicle detection operation in the embodiment.

FIG. 4 is a diagram showing a state where a line sensor is attached to a conventional vehicle detection device.

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

FIG. 6 is a diagram illustrating a motorcycle detection operation of the 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 Motorbike 6 Vehicle width 7 Signal change width 11 Lane boundary 12 Lane center 13 Field of view overlap 20 Signal processing unit 21 Signal processing unit 22 CPU

Continuation of the front page (56) References JP-A-6-251284 (JP, A) JP-A-8-30893 (JP, A) JP-A-7-244796 (JP, A) , U) Table 6-508452 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/00-9/02 G06T 1/00 280

Claims (1)

(57) [Claims] 1. A gantry provided above a road having a plurality of lanes and in the lane width direction, and a plurality of line sensors provided to the gantry so as to be located at the center of each lane and on the boundary between the lanes. The field of view of each line sensor is set to be equal to or larger than the lane width so as to overlap the lane center and the boundary line, respectively, and to overlap the field of view of the line sensor which is one distance away from the line sensor at the lane center or the boundary line about the bike width. And a signal processing device for detecting a passing vehicle based on a detection signal from the line sensor.