JPH10105867A - Vehicle measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle measuring device which can easily detect a high speed vehicle, whose measuring precision is not affected by peripheral environment and whose installation is easy. SOLUTION: Sensor parts 5A, 5B and 5C are arranged on a road R at an equal interval L in the crossing direction of the road R. They are provided with light projection means, light reception means and angle measuring means. Laser light beams are projected on the road R from the respective sensor parts so as to execute scanning. Reflected light beams from the vehicle 50 passing on the road R are received by the sensor parts and the vehicle width and the vehicle height of the vehicle 50 are calculated based on the crossing points of the light reception area in the respective sensor parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle measuring device which is installed in a toll road, a toll parking lot, a multi-story parking facility, and measures the shape of a passing vehicle.

[0002]

2. Description of the Related Art Conventionally, as a device for measuring a vehicle shape such as a vehicle width and a vehicle height, there are a device using a television camera and a device using an array in which photoelectric switches are juxtaposed. A device using a television camera detects a vehicle based on image information of a road surface captured by a television camera, and an array device using a photoelectric switch includes a light projecting unit and a light receiving unit. The vehicle is detected on the basis of a light receiving pattern obtained when light emitted from the unit is blocked by the vehicle and received by the light receiving unit.

[0003]

However, in a system using a television camera, (1) imaging can be performed only at a timing higher than the video rate of an imaging signal, and detection of a vehicle running continuously at high speed cannot be detected. Have difficulty. (2) Measurement accuracy is greatly affected by ambient illuminance. There is a problem.

In an array type device using a photoelectric switch, (3) in order to measure the vehicle width, it is necessary to embed a light emitting portion or a light receiving portion in a road, so that installation work is troublesome and
It is easily affected by dirt such as mud. There is a problem. Therefore, the present invention has been made in view of such problems (1) to (3), and it is easy to detect a high-speed vehicle, the measurement accuracy is not affected by the surrounding environment, and the installation work is simple. It is an object to provide a simple vehicle measuring device.

[0005]

To achieve the above object, a vehicle measuring device according to claim 1 of the present invention is disposed above a vehicle passing area at a distance in a cross direction of a road surface,
A plurality of light projecting means for projecting and scanning a light beam in a transverse direction of a road surface, and a vehicle which is disposed above the vehicle passage area in correspondence with each light projecting means and which emits a light beam from the corresponding light projecting means. A plurality of light receiving means for receiving the reflected light from the passage area,
A vehicle for measuring the size of a vehicle passing on a road surface based on an intersection of an angle measuring means for measuring a light receiving area angle of reflected light received by each light receiving means and a light receiving area of reflected light detected by each angle measuring means. And a shape calculating means.

In this device, a light projecting means and a light receiving means are arranged above a vehicle passing area, and the light receiving means receives reflected light by a light beam projected and scanned from the light projecting means, and receives a reflected light in a light receiving area. The angle is measured by angle measuring means, the end of the vehicle is detected at the intersection of the light receiving areas, and the size (vehicle width or vehicle width and height) of the vehicle is measured based on the detected end. Therefore, it is possible to detect a high-speed vehicle, and it is hardly affected by the surrounding environment (illuminance). Moreover, it is sufficient to install the vehicle above the vehicle passage area, the installation work is easy, and it is hardly affected by dirt such as mud.

A vehicle measuring device according to a tenth aspect of the present invention is provided with a pair of light projecting means arranged at both ends above a vehicle passing area for projecting and scanning a light beam in a direction transverse to a road surface.
A pair of light receiving means arranged on both ends above the vehicle passing area corresponding to the respective light projecting means and receiving reflected light from the vehicle passing area by light beam projection from the corresponding light projecting means, Angle measuring means for measuring the light receiving area angle of the reflected light received by each light receiving means, and vehicle shape calculating means for determining the size of the vehicle passing on the road surface based on the light receiving area angle obtained by each angle measuring means. It is characterized by having.

This device has the same structure as the device of the first aspect, but has a simple structure in that it has a pair of light projecting means and light receiving means, and has a simple structure and vehicle dimensions (vehicle width).
Can be measured.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1 shows a signal processing block diagram of a schematic configuration of a vehicle measurement device according to one embodiment. This vehicle measuring device includes a light projecting means 1 for emitting a light beam, a light receiving means 2 for receiving light reflected by the light beam, an angle measuring means (photodiode) 3 for measuring a light receiving area angle of the reflected light, Vehicle shape calculating means (signal processor) 4 for obtaining vehicle width, vehicle height, and the like;

In this embodiment, the light paths of the light projecting means 1 and the light receiving means 2 are set coaxially, the light beam from the light projecting means 1 is projected and scanned by the polygon mirror 12, and the reflected light is also received by the polygon mirror 12. The scanning is performed, and the light beam and the reflected light are set to be separated by the half mirror 13. The light projecting means 1 includes a laser diode 10 as a laser light source, a light projecting lens 11 for converting laser light into parallel light, and a scanning mechanism having a polygon mirror 12 for projecting and scanning the parallel light in a direction transverse to the road surface. Having. The light receiving means 2 has a scanning mechanism for light projection and scanning having a polygon mirror 12 and the like for scanning the reflected light, a light receiving lens 14 for condensing the reflected light, and a photodiode 15 for receiving the condensed light.

The laser diode 10 is driven by an LD driver 16 based on a fixed period set by a pulse generator 17 controlled by the signal processor 4, and is set to emit pulses at different timings. The light receiving signal of the photodiode 15 is converted into a voltage by an I / V + amplifier 18 and amplified, and the amplified signal is processed by a peak hold process 19, and the signal is digitally converted by an A / D process 20. The signal is converted into a signal and taken into the signal processor 4. The light receiving signal of the photodiode 3 is converted into a voltage by an I / V + binarization process 21, binarized at a predetermined voltage level, and taken into the signal processor 4. The signal processor 4 has a function of controlling the pulse generator 17, a function of calculating the width and height of the vehicle based on the input signal (vehicle shape calculating means), a function of controlling the communication function 22, a function of the photodiode, 3, the scanning angle (that is, the light receiving area angle) that can be taken by the rotation of the polygon mirror 12, and the polygon mirror 12 when the light beam enters the photodiode 3.
And the like to measure the light receiving area angle from the angle of

The communication function 22 exchanges data processing, a sensor controller, and a vehicle type determination 23 with the outside through an interface conforming to, for example, RS485, and outputs the determined vehicle width and height, the vehicle type image, the vehicle determination, and the like. . Next, the principle of vehicle shape measurement (calculation of vehicle width and vehicle height) by the vehicle measuring device configured as described above will be described. 2 and 3, here, three sensor units 5A, 5B and 5C are arranged on a road surface R at equal intervals L in the transverse direction. Each of the sensor units 5A, 5B, and 5C includes the light projecting unit 1, the light receiving unit 2, the angle measuring unit 3, and the like as described above. From each sensor section 5A, 5B, 5C,
Each of the laser beams is projected and scanned toward the road surface R. When the vehicle 50 comes on the road surface R, the vehicle 50 is irradiated with laser light. If the end (corner) of the vehicle 50 can be specified, the width and height of the vehicle 50 can be measured.

The reflected light from the vehicle 50 is transmitted to each sensor 5
A, 5B, and 5C are respectively incident as shown by solid lines.
Here, the incident angle of the reflected light of the sensor unit 5A (the light receiving area angle)
Degree) is α_Two, The incident angle of the reflected light of the sensor unit 5B is β_Two,
The incident angle of the reflected light from the sensor unit 5C is γ_TwoAnd the angle α₁,
β₁, Γ₁Are opposite from the laser beam scanning start position.
The angle to the area where the light exits, the angle α_ThreeIs the sensor
Line perpendicular to the road surface R from 5A and the line that touches the end of the vehicle 50
And the angle β_ThreeIs from the sensor unit 5B to the road surface R
Is the angle between the perpendicular to the line and the line tangent to the end. Also, distance
The distance D is the distance from the sensor unit 5A (5B, 5C) to the road surface R.
Separation, distance L₁Is from the sensor unit 5A to the upper surface of the vehicle 50
Is the distance. Furthermore, from the sensor unit 5A to the end of the vehicle 50
The distance to the side is W_aFrom the sensor unit 5C to the vehicle 5
The distance to the side face on the end side of 0 is W _cIt is.

The distance L and the distance D are determined by the sensor units 5A, 5B,
This is a known value obtained when 5C is installed. Vehicle 50
Can be measured in advance because the angles α ₃ and β ₃ corresponding to the intersections of the end portions are the angles formed by the lines tangent to the end portions and the perpendicular lines in the installation state of the sensor units 5A and 5B as described above. Therefore, the distances L ₁ , W _a , and W _c are obtained as follows with the sensor unit 5A as the origin.

[0015] _{W a = L 1 tanα 3 ···} (1) W a -L = L 1 because tanβ is ₃ (2), formula _{(1), L 1 = L} / ( from (2) _{tanα 3 -tanβ 3) ··· (3} ) next, L ₁ is obtained from the equation (3). Therefore, the vehicle height can be calculated from “vehicle height = D−L ₁ ”.

[0016] On the other hand, the obtained L ₁ and W _a from the equation (1) is obtained. Further, the sensor units 5B, 5
Targeting C, and the sensor portion 5C and the origin by performing the calculation process in the same manner as above, W _c is obtained. Therefore, the vehicle width can be calculated from “vehicle width = W _a + W _c −2L”.
The above embodiment is an example in which the height and width of the vehicle are calculated, but the vehicle width may be calculated in another configuration. FIG. 4 shows the embodiment. Here, a pair of sensor units 5A and 5C is installed on both ends of the road surface R, and both sensor units 5A and 5C
The interval between them is 2L. Also, the angle between the perpendicular from sensor section 5A to road surface R and the line contacting the lower right end (tire) of vehicle 50 is α ₄ , and the perpendicular from sensor section 5C to road surface R and the line contacting the lower left end (tire) are Angle γ ₄ , vehicle 50
Distance of width W, from the sensor unit 5A distance to the vehicle 50 is W _a, from the sensor unit 5C until the vehicle 50 is W _c. Then, the distance W _a, W _c, since the _{W a = Dtanα 4 W c =} Dtanγ 4, the vehicle width can be calculated by _{"W = 2L- (W a + W} c) ."

Further, various examples of the vehicle measuring device having the above configuration will be described. In the above example, the end of the vehicle 50 is at a right angle (see FIG. 5A), but if the end is a curved surface, the reflected light is as shown in FIG. 5B. That is, since the shape of the laser beam is finite, the angle dependence of the reflected light differs between the case where the end of the vehicle is a right angle and the case where the end is a curved surface. Therefore, it is possible to estimate a curved surface from these different features. This is shown in FIG. According to (c), in the relationship between the incident angle α of the reflected light and the amount of received light, when the end of the vehicle is at a right angle, the amount of received light decreases sharply at a certain angle, and when it is a curved surface, the amount of received light decreases. The degree of decrease in the amount of received light changes depending on the angle. By capturing the change in the degree of decrease in the amount of received light, the end of the curved surface can be clearly specified. For example, the degree of decrease in the amount of received light in the case where curved surfaces having a plurality of curvatures are arranged in a sample at spatial positions where the end of the vehicle 50 may exist in the vehicle passage area is stored in a table in advance, and the degree of decrease is measured. The end of the vehicle 50 is specified by matching with the received light amount change.

There is no problem when the color of the vehicle 50 is white and the light reflectance is high, but when the color of the vehicle 50 is black and the light reflectance is low, it is difficult to distinguish between the vehicle and the road surface. Therefore, the received light amount of the reflected light from the road surface when the vehicle does not exist is stored in advance corresponding to the incident angle, and the received light amount signal (data of only the road surface) is obtained when the vehicle passes. Subtraction or subtraction / differential processing is performed from the received light amount signal of the reflected light, and the end of the vehicle can be specified from the obtained signal corresponding to the incident angle. For example, in FIG. 6A, the amount of received light only on the road surface is constant irrespective of the incident angle α of the sensor unit 5A, and the amount of received light changes in a pattern as shown when a vehicle comes. The light reception amount data of only the road surface is subtracted from the light reception signal to specify the end of the vehicle. Further, when the signal of FIG. 6A is differentiated, the signal becomes as shown in FIG. 6B, and the end of the vehicle is emphasized. This makes it easier to identify the end.

The light beams from the sensor units 5A, 5B, 5C are pulsed lights output at different timings. In FIG. 7, each of the sensor units 5A, 5B, and 5C emits a pulse light at the same cycle and shifted by a predetermined time. In each of the sensor units 5A, 5B, and 5C, as shown in FIG. 8, the optical paths of the light projecting means 1 and the light receiving means 2 are coaxial, and light projection and light reception are performed through the same optical path. Light emission and light reception are separated.

When the width of the vehicle is narrow, for example, when the vehicle is a motorcycle, the lowest value (narrowest angle of incidence) is selected from the incident angles of the sensor units 5A, 5B, 5C, and the lowest value is equal to or less than a predetermined value. In the case of, the vehicle is determined to be a two-wheeled vehicle, whereby the four-wheeled vehicle and the two-wheeled vehicle can be identified. Sensor unit 5A, 5
If the optical windows B and 5C (light beam emission / reflected light incident portions) become dirty with the passage of time, the amount of light directly reflected by the dirt increases without being projected to the road surface. In the state where there is no vehicle on the road surface (no vehicle state), the amount of light received from the road surface is detected, and this received light amount is stored as an initial value. When the optical window is increased beyond the initial value, it can be determined that the optical window is dirty. In this case, if the dirt is left unchecked, the measurement accuracy will deteriorate. Therefore, a notifying means (a lamp, a buzzer, etc.) for notifying that effect or a cleaning means (various known ones) for cleaning the optical window is provided. Alternatively, the notification means and the cleaning means may be used in combination.

For example, in FIG. 9, a light receiving element (light receiving amount detecting means) 30 is provided in parallel with a sensor section supporting body 40 for supporting the sensor section. Is always detected. The signal from the light receiving element 30 is amplified by the amplifier 31, and a determination process (determining means) 32 determines whether or not the amount of received light is equal to or more than an initial value. If the received light amount is equal to or more than the initial value, that is, if it is determined that the optical window is dirty, the optical window of each sensor unit is automatically cleaned by the cleaning process (cleaning means) 33.

In the example shown in FIG. 10, two sensor support members 41 and 42 for supporting the above-mentioned sensor units 5A, 5B and 5C are installed at a distance in the longitudinal direction of the road surface R. A black line band 4 is provided on a road surface R portion where the laser beams from the sensor units of the bodies 41 and 42 are projected and scanned.
3 and white line belt 44 are laid. The black line band 43 is for measuring a vehicle with a white body and the white line band 44 is for measuring a black vehicle. That is, in the case of a white vehicle having a high light reflectance of the vehicle body, the black line band 43 reduces the reflected light from the road surface R, so that the reflected light from the vehicle becomes clearer and the measurement accuracy is improved. On the other hand, in the case of a black vehicle having a low light reflectance of the vehicle body, the amount of light reflected from the white line band 44 increases, so that the angle of the light-shielded area blocked by the vehicle is captured as the angle of incidence of the reflected light from the vehicle. The vehicle shape can be recognized with high accuracy.

[0023]

The vehicle measuring device of the present invention has the following effects because it is configured as described above. (1) High-speed vehicles can be detected. (2) Hardly affected by surrounding environment (illuminance). (3) It may be installed above the vehicle passage area, the installation work is easy, and it is hardly affected by dirt such as mud.

[Brief description of the drawings]

FIG. 1 is a signal processing block diagram of a schematic configuration of a vehicle measurement device according to an embodiment.

FIG. 2 is a diagram illustrating the principle of measuring the vehicle shape of the apparatus.

FIG. 3 is another diagram illustrating the principle of measuring the vehicle shape of the apparatus.

FIG. 4 is a diagram illustrating a vehicle shape measurement principle of a vehicle measurement device according to another embodiment.

FIGS. 5A and 5B are diagrams for explaining that measurement of a vehicle shape is different depending on the shape of a vehicle end; FIG. 5A is an explanatory diagram when the vehicle end is at a right angle; FIG. (B) and FIG. (C) showing the amount of received light with respect to the incident angle.

FIG. 6 is a diagram for explaining a method of measuring a vehicle shape from a light receiving signal, and is a diagram (a) showing a light receiving amount with respect to an incident angle, and subtracting and differentiating a light receiving amount data of only a road surface from the light receiving signal; FIG. 6B is a diagram showing a signal obtained by the above.

FIG. 7 is a diagram showing a pulse emission cycle of laser light from each light projecting unit.

FIG. 8 is a diagram showing a case where the light paths of light emission and light reception are coaxial.

FIG. 9 is a diagram showing a configuration for coping with a case where the optical windows of the light projecting unit and the light receiving unit are soiled.

FIG. 10 is a diagram illustrating a configuration in which measurement is performed separately on a vehicle having a white body and a vehicle having a black vehicle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light emitting means 2 light receiving means 3 angle measuring means 4 signal processor (vehicle shape calculating means) 50 vehicle R road surface

Claims (10)

[Claims] 1. A plurality of light projecting means arranged above a vehicle passage area at intervals in a direction transverse to a road surface for projecting and scanning a light beam in a direction transverse to the road surface; A plurality of light receiving means arranged to correspond to the light emitting means and receiving reflected light from a vehicle passing area by light beam emission from the corresponding light emitting means; and a light receiving area angle of the reflected light received by each light receiving means And a vehicle shape calculating means for calculating a size of a vehicle passing on a road surface based on an intersection of light receiving areas of reflected light detected by the angle measuring means. Measuring device. 2. The vehicle measuring device according to claim 1, wherein said vehicle shape calculating means estimates a vehicle shape based on a change pattern of a received light amount of reflected light with respect to a light receiving area angle. 3. The vehicle shape calculating means according to claim 1, wherein said light quantity signal with respect to a light receiving area angle of the reflected light from the road surface in a state where no vehicle is present, and a light receiving area angle of the reflected light from the road surface in a state where the vehicle is present. 2. The vehicle measuring device according to claim 1, wherein the vehicle measuring device performs subtraction or subtraction / differentiation processing on the received light amount signal for estimating the vehicle shape based on the obtained signal for the light receiving region angle. 4. A vehicle measuring apparatus according to claim 3, wherein a vehicle shape is estimated by extracting an increase / decrease change point in a signal with respect to a light receiving area angle obtained by said subtraction or subtraction / differential processing. . 5. A light beam from each of the light projecting means is a pulsed light output at a different timing, and the light paths of the light projecting means and the corresponding light receiving means are coaxial. The vehicle measuring device according to claim 1. 6. A vehicle passing on a road surface is determined to be a two-wheeled vehicle when a minimum value of a light receiving area angle of reflected light detected by the angle measuring means is equal to or less than a predetermined value. The vehicle measuring device according to claim 1. 7. A sensor group comprising a plurality of light emitting means, a light receiving means, and an angle measuring means, each of which is disposed at a distance in a longitudinal direction of a road surface, and a light emitted from the light emitting means of one of the sensor groups. 2. The vehicle according to claim 1, wherein the light reflectance of the road surface irradiated with the beam is reduced, and the light reflectance of the road surface irradiated with the light beam from the light projecting means of the other sensor group is increased. Measuring device. 8. A vehicle measuring apparatus according to claim 1, wherein said vehicle shape calculating means estimates the shape of the end of the vehicle based on the degree of change in the amount of light received by the light receiving means. 9. The vehicle size calculated by the vehicle shape calculating means is:
2. A vehicle width or a vehicle width and a vehicle height.
The vehicle measuring device according to the above. 10. A pair of light projecting means which are respectively disposed at both ends above a vehicle passage area and project and scan a light beam in a transverse direction of a road surface, and each light projecting means at both ends above the vehicle passage area. And a pair of light receiving means for receiving the reflected light from the vehicle passage area by the light beam emission from the corresponding light emitting means, and a light receiving area angle of the reflected light received by each light receiving means. A vehicle measuring device comprising: an angle measuring means for measuring; and a vehicle shape calculating means for calculating a size of a vehicle passing on a road surface based on a light receiving area angle obtained by each angle measuring means.