JPH0855293A - Vehicle detecting device - Google Patents

Abstract

PURPOSE:To provide the vehicle detecting device which can accurately detect the width, passage position, height, and speed of a vehicle even in a special travel state such as side-by-side traveling and traffic jamming without being affected by weather conditions. CONSTITUTION:For plural lanes, e.g. three lanes, line sensors 1-7 are installed on a gantry above a road surface at intervals in the front-rear direction so that their visual fields overlap with one another. The output signals of the line sensors 1-7 are inputted to signal processors 21-27, which decide whether or not there is a vehicle from the state of variation in luminance level and output the results to a,vehicle measuring instrument 30. The vehicle measuring instrument 30 is equipped with a vehicle position and vehicle width measuring means 31, a vehicle speed measuring means 32, and a vehicle height measuring means 33, and measures the entrance/exiting position of a vehicle on the entire road and the vehicle width from the decision results of the signal processors 21-27.

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 detecting entry / passage of a vehicle, a vehicle position, a vehicle width, a vehicle height and a vehicle speed in a single lane and a plurality of lanes.

[0002]

[Prior Art] At toll road toll gates, parking lots, etc.
When automating the operation of issuing a pass ticket or a parking ticket, it is necessary to automatically detect a vehicle entering or passing through. As a vehicle detection device for this purpose, there is a device that detects and counts vehicles passing on the road from above the road surface. Conventionally, the following (1) ultrasonic method, (2) optical method, (3) are shown below.
The microwave method is used.

(1) Ultrasonic method This ultrasonic method is provided with a vibrator 101 for oscillating and receiving an ultrasonic wave 101a above the road surface as shown in FIG. 10 (a), and detects the distance to the road surface 102. When the vehicle 103 has not entered, the road surface reflection echo is obtained as shown in FIG. 10B, but when the vehicle 103 enters, the vehicle reflection echo 104 returns, so that the reflection time is longer than that of the road surface reflection echo only. It gets shorter. Therefore, the presence of the vehicle 103 can be detected by measuring the time when the reflected echo returns.

(2) Optical method As shown in FIG. 11 (a), this optical method uses the sun 107
The vehicle 103 is detected by monitoring the illuminance on the road surface 102 with the optical sensor 105 based on the light beam 106 from. When the vehicle 103 has not entered the road surface 102, the light amount level is only the road surface color as shown in FIG. 11B, but when the vehicle 103 has entered the light amount level as shown in FIG. 11C. Changes, the presence of the vehicle 103 can be detected from the change in the amount of light.

(3) Microwave system This microwave system measures the frequency of the oscillated microwave. That is, the wave reflected back to the passing vehicle undergoes the Doppler shift, and the wave reflected back to the road surface does not undergo frequency change. Therefore, the passage of the vehicle can be detected by detecting the frequency displacement.

[0006]

The conventional vehicle detection device described above has the following problems. Vehicle detection devices that use ultrasonic or microwave methods have a wide beam width of ultrasonic waves and microwaves and cover a wide lane below the installation position on the road surface. It can detect where a small vehicle passes. For this reason, one sensor has the advantage of covering one lane as a whole, but on the contrary, when a plurality of motorcycles translate in the same lane, they cannot be counted separately. In addition, it is not possible to detect a motorcycle that slips beside a truck on a stagnant road.

As described above, the method using ultrasonic waves or microwaves has a limit in accurately detecting a passing vehicle. Furthermore,
The ultrasonic method has a slow response speed, and it is difficult to detect a motorcycle running at high speed.

In the case of measuring the traffic volume for controlling the traffic lights at the intersection, there is no particular problem even if the miscounting is performed in the above special case, but when it is applied to the toll collection system of the toll road, Such exceptions are not allowed.

Further, unlike the microwave or ultrasonic method, the vehicle detection device based on the optical system is based on the light beam 106 from the sun 107 as shown in FIG. 11, so that the optical sensor 105 is arranged in the width direction within the lane. If the field of view is provided with a fine pitch, it is possible to separate the case where two bikes are translated. However, in this case, when the altitude of the sun 107 is low in the morning or in the evening, the shadow 108 of one vehicle is generated on the road surface 102, and thus the translation of two motorcycles may be erroneously detected as one vehicle. is there.

The present invention has been made in view of the above circumstances, and also in a special traveling mode such as translation or stagnation,
An object of the present invention is to provide a vehicle detection device capable of accurately detecting a vehicle width, a vehicle passage position, a vehicle height, and a vehicle speed without being affected by weather conditions.

[0011]

A vehicle detection device according to the present invention is installed in a gantry such that the fields of view sequentially overlap by ½ and at intervals in the front-rear direction. A plurality of image pickup devices for picking up images, a signal processing device for A / D converting the signals output from each of the image pickup devices, and determining the presence or absence of a vehicle from the change state of the signals, and the signal processing devices Based on the processing results, the vehicle position / vehicle width measuring means for measuring the vehicle entry / passing position and the vehicle width on the entire road, the vehicle height measuring means for measuring the vehicle height, and the vehicle measuring means for measuring the vehicle speed And a device.

[0012]

The image pickup device picks up an image of the road surface of each lane and outputs it to the signal processing device. This signal processing device converts the analog signal of the image pickup device into a digital signal and determines the presence or absence of a vehicle based on the presence or absence of a change in the signal. In addition, the vehicle measurement device detects vehicle entry / passage on the entire road from the vehicle presence / absence determination result of the signal processing device, and measures the vehicle position, vehicle width, vehicle height, and vehicle speed.

At this time, since the image pickup devices are made to overlap each other for image pickup, there are two parallaxes between the two image pickup devices for picking up the same vehicle, and based on the principle of triangulation. The height of the vehicle can be measured, and by arranging them so that they are offset in the front-rear direction, the intervals between the image pickup devices are known. Therefore, by detecting the time difference between entering and passing through the image pickup devices, the vehicle speed can be detected. Can be measured.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the first, second and third lanes 10, 11, 1
2 shows a state in which a plurality of image pickup devices, for example, seven line sensors 1 to 7 are attached to a gantry 8 on a three-lane road having two, where (a) is a top view and (b) is a front view. is there. Further, FIG. 2 shows the visual fields of the line sensors 1 to 7. The gantry 8 is installed on the side of the road and holds the line sensors 1 to 7 at the upper position of the road.
The line sensors 1 to 7, as shown in FIG.
It is installed at the center and boundary of 11 and 12, and captures the image of the road surface directly below. That is, the odd line sensor 1,
3, 5, 7 are installed at the boundaries of the lanes 10, 11, 12 and the even-numbered line sensors 2, 4, 6 are installed in the lanes 1
It is installed at the center of 0, 11, and 12. The odd-numbered line sensors 1, 3, 5, 7 and the even-numbered line sensors 2, 4, 6 are arranged at a predetermined distance d in the traveling direction of the vehicle 9. For example, odd-numbered line sensors 1, 3,
5 and 7 are vehicles 9 from even-numbered line sensors 2, 4 and 6
It will be placed on the approach side of.

The line sensors 1 to 7 are shown in FIG.
As shown in FIG. 2, the vehicle has one lane field of view (line sensors 1 and 7 on both ends have 1/2 lane field of view) 61 to 67, and the field of view with the adjacent line sensor overlaps by 1/2. are doing.

FIG. 3 is a block diagram showing the circuit configuration of the vehicle detection device. In the case of a three-lane road, the vehicle detection device includes, for example, the seven line sensors 1 to 7, the signal processing devices 21 to 27 that process signals from the line sensors 1 to 7, and the vehicle measurement device 30. Composed.
This vehicle measuring device 30 is a vehicle position / vehicle width measuring means 3
1. A vehicle speed measuring means 32 and a vehicle height measuring means 33 are provided to perform measurement processing for each lane 10, 11, 12. That is, the vehicle measuring device 30 determines the determination results of the signal processing devices 21 to 23 for the first lane 10, the determination results of the signal processing devices 23 to 25 for the second lane 11, and the determination results of the signal processing device 25 for the third lane 12. A measurement process is performed using the determination results of ~ 27. Then, the measurement result of the vehicle measurement device 30 is sent to the pass ticket issuing device, the toll collection device, or the like.

The signal processing devices 21 to 27 perform A / D conversion on the video signals received from the line sensors 1 to 7, respectively, and determine the presence or absence of a vehicle from the change in the brightness on the road surface. Hereinafter, this vehicle presence / absence determining method will be described in detail.

The image signals picked up by the line sensors 1 to 7 have low luminance and a smooth video signal 51 is obtained as shown in FIG. This video signal 51 is used as a reference signal for reference in advance in the signal processing device 2.
It is stored in 1-27. Also, with the vehicle present,
As shown in FIG. 4B, a video signal 52 whose brightness is high only at the place where the vehicle enters is obtained. Therefore, in the signal processing devices 21 to 27, the presence of the vehicle 9 is determined from the difference in brightness by comparing the previously stored video signal 51 without a vehicle with the signals sequentially captured by the line sensors 1 to 7. Can be detected.

The signal processing devices 21 to 27 determine the presence or absence of a vehicle based on the signals picked up by the line sensors 1 to 7 as described above, and output the determination result to the vehicle measuring device 30. The vehicle measurement device 30 includes signal processing devices 21 to 27.
Is processed by the vehicle position / vehicle width measuring means 31, the vehicle speed measuring means 32, and the vehicle height measuring means 33 to determine the vehicle position / vehicle width,
Find vehicle speed, vehicle height, etc. FIG. 5 shows a vehicle 9 in the first lane 10.
When the vehicle 9 exists immediately below the line sensor 2, the vehicle presence / absence determination results 41 to 43 of the signal processing devices 21 to 23 and the vehicle position / vehicle width measuring means 31 in the vehicle measuring device 30 are detected. It shows an integration processing result 44 that integrates these signals (takes a logical product).

The line sensor 2 located in the center of the first lane 10 takes an image of the entire width of the first lane 10, but since the vehicle 9 has a certain height, the brightness in a wider range than the actual vehicle width. Becomes higher. Therefore, the vehicle presence / absence determination result 42 of the signal processing device 22 is determined to be wider than the actual vehicle width of the vehicle 9. Further, the line sensors 1 and 3 located on both sides of the line sensor 2 are set so that the first lane 10 is imaged while being overlapped by ½, that is, the visual field range with respect to the first lane 10 is set to ½. Therefore, only part of the vehicle 9 is imaged, and the vehicle presence / absence determination results 41, 43 of the signal processing devices 21, 23 are determined to be narrower than the actual vehicle width of the vehicle 9. However, this vehicle presence / absence determination result 41,
43 accurately indicates the position of the side portion of the vehicle 9. Therefore, the vehicle position / vehicle width measuring means 31 obtains a logical product of the vehicle presence / absence determination results 41 to 43 to obtain an integrated processing result 44 representing an accurate vehicle position and vehicle width.

As described above, in the vehicle position / vehicle width measuring means 31, the vehicle presence / absence determination results of the signal processing devices 21 to 27 are logically ANDed for each lane to accurately detect the vehicle and its vehicle width and passing position. Can be measured.

Next, the speed measuring method will be described. Figure 6
8 shows the vehicle presence / absence determination results 41 to 43 and the integrated processing result 44 of the signal processing devices 21 to 23 when the vehicle 9 enters the visual field range of the line sensors 1 to 3.
FIG. 6 shows a case where the vehicle 9 has not entered the field of view of the line sensors 1 to 3, and none of the vehicle presence / absence determination results 41 to 43 of the signal processing devices 21 to 23 has a vehicle detection signal and the integrated processing result. Also at 44, no vehicle is detected.

FIG. 7 shows a state in which the vehicle 9 is entering the visual field of the line sensor 2, and only the vehicle presence / absence determination result 42 of the signal processing device 22 is detected. However, when the logical product of the vehicle presence / absence determination results 41 to 43 of the signal processing devices 21 to 23 is taken, it is determined that there is no vehicle in the integrated processing result 44. FIG. 8 shows a case where the vehicle 9 has entered the visual fields of the line sensors 1 to 3, and the vehicle 9 is detected in the vehicle presence / absence determination results 41 to 43 of the signal processing devices 21 to 23. Therefore, the integrated processing result 44 obtained by ANDing the vehicle presence / absence determination results 41 to 43 is also determined to be a vehicle.

In the vehicle speed measuring means 32, the signal processing device 22
From the time t1 when the vehicle 9 detects the vehicle 9 and the time t2 when the signal processing device 21 or the signal processing device 23 detects the vehicle 9, and the distance d between the line sensors 1 and 3 and the line sensor 2 from the vehicle 9
The passing speed v of is calculated by the following equation. v = d / (t2-t1) In this case, the human detection is excluded by setting the attachment interval d between the line sensors 1, 3, 5, 7 and the line sensors 2, 4, 6 larger than the human width. That is, it is possible not to be influenced by humans.

Next, the vehicle height measuring means 3 in the vehicle measuring device 30
A case in which the vehicle height of the vehicle is obtained according to 3 will be described.
As shown in FIG. 9, the vehicle 9 obtained from the distance L between the line sensor 1 and the line sensor 2, the mounting height H of the line sensors 1 to 7, and the vehicle presence / absence determination result 41 of the signal processing device 21.
Of the vehicle 9 obtained from the vehicle presence determination result 42 of the signal processing device 22 from the end of the
The height h of the vehicle 9 is measured by the following formula based on the principle of triangulation from the distance d2 from the end of the line sensor to just below the line sensor 2. h = H (d2-d1) / d2 As described above, the vehicle measuring device 30 processes the vehicle presence / absence determination result signals output from the signal processing devices 21 to 27 for each lane, so that Vehicle position, vehicle width, vehicle speed, vehicle height, etc. can be measured. Also,
By arranging the line sensors so that the FOVs of each lane overlap each other by ½, even when the two motorcycles are translating or in a special running mode such as a stagnation, the vehicle can be adjusted depending on the weather conditions. In the case where there is a shadow on the background, the measurement process can be reliably performed without being affected by the shadow. In addition, in the said Example, although the case where it implemented in multiple lanes was demonstrated, it can implement even in a single lane similarly to the said Example.

[0026]

As described above in detail, according to the present invention, in a single lane and a plurality of lanes, the presence or absence of a vehicle and the width of the vehicle can be prevented without being affected by special traveling modes such as translation and stagnation and weather conditions. Also, the vehicle position can be measured, and the passing speed and vehicle height of the vehicle can be measured.

[Brief description of drawings]

FIG. 1 shows a state in which a line sensor is attached to a vehicle detection device according to an embodiment of the present invention, (a) is a top view,
(B) is a front view.

FIG. 2 is a diagram for explaining a field of view of a line sensor in the embodiment.

FIG. 3 is a block diagram showing a circuit configuration in the embodiment.

FIG. 4 is a diagram for explaining a signal processing operation of the signal processing device in the embodiment.

FIG. 5 is an explanatory diagram for explaining vehicle position and vehicle width measurement in the embodiment.

FIG. 6 is a diagram for explaining a vehicle speed measuring operation in the embodiment.

FIG. 7 is a diagram for explaining a vehicle speed measuring operation in the embodiment.

FIG. 8 is a diagram for explaining a vehicle speed measuring operation in the embodiment.

FIG. 9 is a diagram for explaining a vehicle height measuring operation in the embodiment.

FIG. 10 is an explanatory diagram of a conventional ultrasonic detection vehicle detection device.

FIG. 11 is an explanatory diagram of a vehicle detection device using a conventional optical sensor method.

[Explanation of symbols]

 1-7 Line sensor 8 Gantry 9 Vehicles 10, 11, 12 Lanes 21-27 Signal processing device 30 Vehicle measuring device 31 Vehicle position / vehicle width measuring means 32 Vehicle speed measuring means 33 Vehicle height measuring means 41 Vehicle presence / absence of signal processing device 21 Determination result 42 Vehicle presence / absence determination result of the signal processing device 43 Vehicle presence / absence determination result of the signal processing device 23 44 Integrated processing result 51 Video signal without vehicle 52 Video signal with vehicle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiro Fujita 1-1-1 Wadazaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard

Claims (1)

[Claims] 1. A plurality of image pickup devices, which are installed in a gantry such that the fields of view sequentially overlap each other by 1/2 and are spaced at an interval in the front-rear direction, and which pick up a grayscale image of a road surface. A signal processing device that A / D-converts each output signal and determines the presence / absence of a vehicle based on the change state of the signal, and a processing result determined by each signal processing device determines whether the vehicle enters / passes the entire road. A vehicle detection device comprising: a vehicle position / vehicle width measuring means for measuring a position and a vehicle width; a vehicle height measuring means for measuring a vehicle height; and a vehicle measuring device having a vehicle measuring means for measuring a speed. .