JPS6153523A - Apparatus for discriminating kind of car - Google Patents

Abstract

PURPOSE:To enable the discrimination of the kind of a car even with respect to a car having the same number of axles, by detecting not only the number of axles but also the wt. of the axles by a load detection part consisting of a pressure plate and a pressure sensor. CONSTITUTION:A plurality of load detection parts 30, each of which is constituted of the pressure plate 31 and support 32 mounted to the cavity part of a step plate in an inserted state and the pressure sensor 40 held therebetween, are provided and, when pressure detection output equal to or more than the threshold values of the detection parts is counted, the number of the oxide of an advancing or backing vehicle is discrminated. The load of the vehicle is determined on the basis of the output sum of the detection parts 30 and the kind of the vehicle can be discriminated even with respect to the vehicle having the same number of axles.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle type discrimination device used in an automatic toll collection system on a toll road or a parking lot, and particularly relates to an improvement in vehicle type discrimination factor detection means.

[Conventional technology]

Generally, in a toll collection system for a toll road or a parking lot, a vehicle type discrimination device is installed to discriminate the type of vehicle passing by.

FIG. 5 is a schematic diagram showing the appearance of the vehicle type discrimination device.

In FIG. 5, reference numeral 1 indicates a passing vehicle, which travels along the vehicle approach road 2 in the direction of the arrow. Reference numeral 3 denotes a vehicle type discrimination device, which includes optical vehicle detectors 4a and 4b installed facing each other across the vehicle approach road 2, and this vehicle detector 4a.
, 4b, and a footboard 5 buried in the road surface below the optical axis of the optical axis.

FIGS. 6 and 7 are an external perspective view and a vertical sectional view of the step board 5. FIG. In FIGS. 6 and 7, reference numeral 11 denotes a footboard body, which is made of an elastic material such as rubber. The tread body 11 has four cavities 12a, 12b, 12c.
, 12d are provided, and these cavities 12a to 1
2d includes 1!, which will be described later. Point bodies 20 (20a, 20b, 2
0c, 20d) are inserted respectively. Note that 13 is a substrate that supports the contact body 20 and has a rigid structure.

FIG. 8 is a longitudinal sectional view of the contact body 20. In FIG. 8, 21 is a rectangular cylinder formed of an elastic body such as rubber, and electrodes 2 are arranged on the inner wall of the rectangular cylinder 21 to face each other vertically.
2.23 is attached.

Now, when the passing vehicle 1 approaches the vehicle type discrimination device 3 and presses the treadle 5 in the direction of arrow A or B in FIG.
The rectangular cylinder 21 of the contact body 20 is deformed, and both electrodes 22.
23 is short-circuited, and the pedal pressure of the wheel is detected. Then, the contact body 20 changes from 20a to 2 according to the order of pressure on the wheels.
0b→20c→20d, or 20d-+20c→20
They operate in the order of b-20a, and a forward/reverse signal indicating whether the passing vehicle 1 is moving forward or backward is output. and vehicle detector 4a
, 4b are shielded from light by counting the forward/reverse signals by 4 using an up/down counter (not shown), thereby detecting the number of axles for each vehicle as a factor for determining the vehicle type. As a result, a discriminating circuit (not shown) discriminates the vehicle type based on the number of axes.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional vehicle type discrimination device, since the vehicle type is discriminated based on the number of axles, there is a drawback that vehicle types cannot be discriminated for vehicles having the same number of axles. For example, two-axle vehicles include large trucks, small trucks, and regular passenger cars.

There are various types of vehicles, including light wheeled vehicles and even motorcycles.
These vehicles will be identified as the same vehicle. Therefore, improvement thereof has been desired.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a vehicle type discrimination device that can discriminate the vehicle type even for vehicles having the same number of axles.

[Means for solving problems]

The present invention is characterized by taking the following measures in order to solve the above problems and achieve the objects.

In other words, a footboard is buried in the road surface under the optical axis of the optical vehicle detector installed opposite to each other across the vehicle approach road, and a pressure sensing device is placed in the cavity of the footboard using a rigid pressure plate and a support. The present invention is characterized in that a load detection section having a sensor sandwiched therein is inserted, and the number and type of axle of a passing vehicle is detected from the output signal of a pressure-sensitive sensor in this load detection section to identify the vehicle type. .

[Effect]

By taking such measures, not only the number of axles of a passing vehicle but also the axle type can be detected, so that it is possible to perform detailed classification of vehicle types.

〔Example〕

FIG. 1 is a longitudinal sectional view showing the configuration of a load detection section 30 in an embodiment of the present invention. The load detection section 30 includes four cavities 12a to 12 of the tread body 11 explained in FIG.
tLII respectively at d. 1st
In the figure, 31 is a pressure plate, 32 is a concave support body,
Each has a rigid structure. 4o is a pressure sensor. The pressure sensor 40 is disposed in a recess of the support body 32, and is housed and held in the recess with the pressure plate 31 placed thereon. It is held between the sides.

In this case, the lateral gap ΔQ between the pressure plate 31 and the support body 32 is so small that no resistance contact occurs between them. Further, the upper surface of the pressure plate 31 is connected to a support body 32.
It projects above the upper end surface by Δh. Note that, since the deformation of the pressure sensor 40 when pressurized is negligibly small, the above-mentioned protruding portion does not sink.

FIG. 2 is a longitudinal cross-sectional view showing the structure of the pressure-sensitive sensor 40. As shown in FIG. In FIG. 2, numeral 41 is a piezoelectric sheet made of thin plastic film, and thin film electrodes 42 and 43 are attached to both surfaces of this piezoelectric sheet 41. Above electrode 42.43
Lead wires 44 and 45 are provided respectively.

FIG. 3 is a block diagram showing the configuration of a signal processing circuit for detecting the number and type of axes based on the output signal of the pressure sensor 40, and FIG. 4 is a signal waveform diagram of each part of the signal processing circuit. . In FIG. 4, the horizontal axis shows the change over time, and the vertical axis shows the change in the output voltage. 40a in FIG.

40b, 40c, and 40d are hollow portions 1 of the tread body 11;
Pressure-sensitive sensors 2a to 12d are shown respectively inserted, and the negative electrode side, that is, the electrode 43 side of each of the sensors 40a to 40d is connected to a common terminal 50. On the other hand, each positive electrode side of the pressure sensitive sensors 40a to 40d, that is, the electrode 4
The second side is connected to the input terminals of matching amplifiers 51a to 51d, respectively. The above matching amplifiers 51a to 5
The output terminal of 1d is connected to each of the threshold circuits 52a to 52d, and is also connected to the input terminal of the adder circuit 53. As shown in FIG. 4, the threshold circuits 52a to 52d are activated when the output voltages E1 to E4 of the matching amplifiers 51a to 51d exceed a preset threshold T. Output terminals 54 of 52a to 52d
Low the binary signals S1 to S4 output to a to 54d.
to High. Further, the adding circuit 53 adds the output voltages E1 to E4 (analog voltages) of the matching amplifiers 51a to 51d, and calculates the sum E.
O is output from the output terminal 55.

Next, the effects of this embodiment will be explained. Passing vehicle 1
When the wheel presses the footboard 5, the footboard main body 11 made of an elastic body deforms and presses the pressure Ifi31. Then, from each of the pressure sensitive sensors 40a to 40d held between the pressure plate 31 and the support body 32, the pressure plate 3
A voltage proportional to the pressing load of 1 is outputted sequentially with a time delay depending on the traveling speed of the passing vehicle 1. In this embodiment, a case is shown in which the passing vehicle 1 moves from the pressure sensor 40a to the pressure sensor 40d.

The voltages output from the pressure sensitive sensors 40a to 40d are amplified by matching amplifiers 51a to 51d, respectively. The amplified amplifier output voltages E1 to E4 are supplied to each of the threshold voltage circuits 52a to 52d, and also to the adder circuit 53. In the threshold circuits 52a to 52d, the amplifier output voltages E1 to E4 are converted into binary signals S1 to S4 according to their respective values, and these binary signals 1iS1 to S4 are output to the output terminals 54a to 54.
4d respectively. And this output terminal 54
Depending on the output order of the binary signals 81-S4 outputted from 8-54O, it is determined whether the passing vehicle 1 is moving forward or backward, and the vehicle detector 4a as in the conventional case.

The number of axes for each vehicle can be detected by counting the forward/reverse signals with an up/down counter (not shown) while 4b is shielded from light.

On the other hand, in the adder circuit 53, each amplifier output voltage E1
.about.E4 are added, and the sum EO is output from the output terminal 55. The sum EO of the amplifier outputs is the total load applied to the footboard 5, that is, the sum total of the axis m. In this way, all types a of the vehicle can be detected from the sum of the shaft types.

As described above, according to this embodiment, the pressure sensitive sensors 40a to 40
Since the number of axles and the type of axle can be detected from the output signal from d, the type of vehicle can be accurately determined from the number of axes and the type of axle by a discriminating circuit (not shown). In other words, for vehicles with the same number of axles, it is possible to perform more detailed and highly accurate vehicle type discrimination than before.

〔Effect of the invention〕

As described in detail above, according to the present invention, a footboard is buried in the road surface under the optical axis of the optical vehicle detector installed opposite to each other across the vehicle approach road, and a rigid structure is installed in the cavity of the footboard. A load detection unit consisting of a pressure sensor sandwiched between a pressure plate and a support is inserted, and the number and type of axle of a passing vehicle is detected from the output signal of the pressure sensor in this load detection unit to identify the vehicle type. Since this is done, it is possible to provide a vehicle type discriminating device that can discriminate the vehicle type even for vehicles having the same number of axles.

[Brief explanation of drawings]

Figures 1 to 4 are diagrams for explaining one embodiment of the present invention, in which Figure 1 is a vertical cross-sectional view showing the configuration of the load detection section, and Figure 2 is a vertical cross-sectional view showing the configuration of the pressure sensor. 3 is a block diagram showing the configuration of a signal processing circuit for detecting the number and type of axes, and FIG. 4 is a signal waveform diagram of each part of the signal processing circuit shown in FIG. 3. Figures 5 to 8 are diagrams for explaining the conventional example, in which Figure 5 is a schematic diagram showing the appearance of the vehicle type identification device, and Figures 6 and 7 are perspective views and longitudinal sections showing the configuration of the treadle. figure,
FIG. 8 is a vertical cross-sectional view showing the structure of the contact body. DESCRIPTION OF SYMBOLS 1... Passing vehicle, 3... Vehicle type identification device, 4... Vehicle detector, 5... Step board, 11... Step board body, 12a
~12d...Cavity part, 13...Substrate, 30...Load detection part, 31...Pressure plate, 32...Support body, 40
(40a-40d)...pressure sensor, 41...piezoelectric sheet, 42.43...electrode, 518-51d...
- Matching amplifier, 528 to 52d... Threshold circuit, 53... Addition circuit. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 5 Figure 7 Figure 8

Claims (1)

[Claims] An optical vehicle detector installed facing each other across the vehicle approach road, a footboard buried in the road surface under the optical axis of the vehicle detector, and a rigid pressure plate inserted into the hollow part of the footboard. and a support body to sandwich a pressure sensor, and a means for detecting the number and type of axles of a passing vehicle from the output signal of the pressure sensor in the load detection section to determine the type of vehicle. A vehicle type identification device that is characterized by: