JPS5812317Y2 - Vehicle identification detector - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vehicle discrimination detector for detecting the number of axles or the number of wheels of a vehicle in an unmanned toll road system or the like to discriminate the type of vehicle.

On toll roads, toll fees are often determined by vehicle type, such as large vehicles and regular vehicles.

On the other hand, in recent years, there has been a trend toward completely unmanned (automated) toll collection operations on toll roads, and such unmanned systems must accurately identify vehicle types.

In conventional systems, an optical sensor is used to detect the vehicle body, and a vehicle identification detector (hereinafter referred to as a treadle) is a switch-type sensor for detecting the number of axles and wheels installed on the road surface.

) detects the number of times the vehicle operates in response to the pressure of the retired tire, and detects whether the number of axles is two or three, or the number of tires, especially whether it is a double tire or not. The figure shows an example of the use of treads on toll roads.

The figure is a perspective view of a tollgate, where 1 is the road surface of the travel lane and 2 is the passing vehicle.

A light emitter 3A and a light receiver 3B, which are optical detectors for distinguishing vehicles 2 one by one, are arranged on both sides of the lane near the toll gate entrance so as to face each other. The vehicles 2 are separated and discriminated one by one by blocking the light beam irradiated toward the device 3B.

Stepboards 4 for detecting the number of axles and wheels are laid on the road surface in the vicinity of the position directly below the light beam irradiated by the projector 3A, approximately the width of the lane.

As shown in FIG. 2, this footboard 4 has pressure-sensitive sensors 5 arranged in a matrix in m rows and n columns.

IF includes these optical detectors and each pressure sensor 5 of the footboard 4.
This is an interface that identifies the vehicle type based on signals from the vehicle, calculates tolls, and performs various other necessary controls.

The pressure sensor 5 is an element having a shape as shown in FIG. 3a, and its equivalent circuit is a switch as shown in FIG. 3, and the switch is configured to close when pressure is applied to the top surface of the element. .

Examples of pressure-sensitive sensors include mechanical switches, semiconductor pressure sensors, and capacitance change detection sensors.

FIG. 4 is a cross-sectional view of the footboard 4, in which pressure-sensitive sensors 5 are arranged in m rows and n columns on a baseplate 6, and these pressure-sensitive sensors 5, including the baseplate 6, are molded with rubber 7. It is.

Then, such a step board 4 is housed in a groove provided in the road surface 1, and a pressure sensor 6 immediately below and near the step board is operated in response to the pedal pressure from the wheels 2a of a vehicle traveling on the road surface 1 in the direction of the arrow.

With the above-described configuration, the interface IF calculates the number of axles and wheels based on the relationship between the pressure sensor 5 that operates during the period when the optical detector detects the vehicle 2, and determines the type of vehicle.

That is, M) Pressure sensitive sensor 5 arranged in IJ rack shape
If the pressure-sensitive sensors in multiple adjacent rows are operating at the same time, it can be detected that the vehicle is a double-tire vehicle whose wheels are wider than the width of a single tire, and based on the operating status of the pressure-sensitive sensors 5. The number of wheels and axles can be detected, and the direction in which the vehicle is traveling can also be detected depending on the order in which the pressure-sensitive sensors 5 in the column direction operate.

By the way, for the reasons mentioned above, the pressure-sensitive sensors are arranged in a matrix, and the pressure-sensitive sensors used include mechanical switches, semiconductor pressure sensors, and capacitance change detection sensors. Even if it is a pressure sensor, if the matrix is mxn, mxn sensors are required.

In order to maintain detection accuracy, it is desirable that each sensor has the same detection sensitivity and uniform durability.

However, since it is realistically impossible for mXn sensors to satisfy the above conditions, this method has the drawback of having to adjust the sensitivity level of each sensor on the circuit that processes the signal from the footboard. are doing.

This becomes a difficult task when the number of pressure-sensitive sensors increases, and when considering changes in pressure-sensitive sensors and sensitivity level adjustment circuits over time, maintenance becomes difficult.

The present invention was developed in view of the above circumstances, and uses a conductive rubber sheet as a pressure sensor whose resistance value changes when pressure is applied, and multiple pairs of electrodes are arranged in a matrix. At the same time, the single sheet-like pressure sensor is arranged on these electrodes, and each set of electrodes is switched according to a change in the resistance value of the pressure sensor, thereby providing a vehicle discrimination detector that eliminates the above-mentioned drawbacks. The purpose is to

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 5 to 8.

The present invention consists of a pressure-sensitive sensor made of conductive rubber, and uses a sheet of this conductive rubber as a treadle, and thereby makes it possible to easily equalize operating characteristics while taking advantage of the characteristics of a matrix arrangement, and is simple. The point lies in the structure.

Here, conductive rubber is a transducer whose electrical resistance changes in response to pressure stimulation, and the magnitude of the resistance change varies from an insulating state (several tens of M0) to a conducting state (several tens of ohms) 1 depending on the magnitude of the pressure. It is a pressure-sensitive resistor with a switching function that changes rapidly.

For example, conductive rubber manufactured by Japan Synthetic Rubber Co., Ltd. has the following properties: non-pressure dark resistance of 103 Ω- and conductive dark resistance of 1O2 Ω-.

It also has the property of being electrically conductive only in the pressurized part.

The properties of the rubber are the same as those of ordinary rubber; for example, the hardness is 70, the density is 3.3 g/h, and the tensile strength is 15 kg/-1 and the elongation is 200%.

The operating pressure varies slightly depending on the type, but the suppression is 0.1 to 3k.
It becomes conductive at g/ffl.

FIG. 5 shows a cross-sectional view of the vehicle discrimination detector according to the present invention, that is, the treadle.

8 in the figure is the above-mentioned conductive rubber sheet that becomes the pressure sensor;
9 is a plate-shaped insulating plate made of Bakelite or the like, and 10 is plywood.

The conductive rubber sheet 8 is arranged in surface contact with the insulating plate 9. On the side of the insulating plate 9 in contact with the conductive rubber sheet 8, there are holes arranged at equal intervals and parallel to the longitudinal direction of the treadle. Book electrodes 11 are provided in a strip shape, and these strip electrodes 11
In parallel with this, a large number of small-area electrodes 12 are provided at equal intervals.

The electrode 11 and the corresponding electrode 12 form a pair.

Further, the electrodes 11 indicate the row direction. Reference numeral 13 denotes a lead wire that connects each electrode 12 in the column direction, and this lead wire 13 is made independent for each column, and is led out through the insulating plate 9.

14 is a hole provided in the insulating plate 9 for leading out the lead wire 13.

An insulating plate 9 on which a conductive rubber sheet 8 is placed is placed on a base plate 10, and the outside thereof is molded with rubber 15.

FIG. 6 is an exploded perspective view showing the structure of the insulating plate 9, and portions denoted by the same reference numerals as those in FIG. 5 indicate the same parts.

The electrodes 11 and 12 are arranged as shown in FIG.
A conductive rubber sheet 8 is provided on these electrodes.

When the conductive rubber sheet 8 is subjected to pressure, the portion that has received this pressure becomes conductive, and the electrode 11.
Twelve pairs will be closed.

A large number of electrodes 12 are arranged parallel to and in parallel with the electrodes 11, so that the electrodes 12 are arranged in a matrix of m rows and n columns, with rows in the direction of the electrodes 11 and columns in the direction in which the electrodes 12 are arranged. This constitutes a non-contact type pressure-sensitive sensor.

FIG. 6 shows the arrangement relationship and connection relationship of the electrodes 12. As shown in the figure, those in the same column direction are connected with the same lead wire 13, and the lead wire of the electrode 11 and the lead wire 13 of the electrode 12 are connected.
Accordingly, the pedal pressure can be detected at each position of the mxn matrix.

Next, the operation of this device having the above configuration will be explained.

If treadboards such as those shown in Figures 5 and 6 are laid on the tread surface with the row direction facing the road width, when a vehicle passes by, the part trampled by the wheel receives the tread pressure and conducts electricity. Since the resistance value of the rubber sheet 8 is drastically reduced, a pair of electrodes 11 and 12 located in this area are electrically connected.

That is, as shown in the schematic diagram of FIG. 7, the part 8A of the conductive rubber sheet 8 that receives the pressure becomes electrically conductive, so that the electrode 11 and the electrodes 12-3 and 12-4 in contact with this part are in a short-circuit state as shown in the figure. Therefore, electrode 11 and electrodes 12-1, 12-
2, 12-5, 12-6 is open (ma) I
It is possible to detect which pair of the electrodes 11 and 12 in the J-lux row is short-circuited, that is, which coordinate position portion of the matrix receives the pedal pressure.

Therefore, the same detection function as when pressure-sensitive sensors are arranged in a matrix can be obtained.

Moreover, the structure uses a conductive rubber sheet to short-circuit pairs of electrodes arranged in a matrix by reducing the resistance value of the pressurized part when pressurized, and since each pair of electrodes is just an electrode, it has individual operating characteristics. However, since the conductive rubber feature is used to drastically reduce the resistance value of the pressurized part, a conductive rubber sheet is placed on top of the pair of electrodes arranged in a matrix. This simple structure has uniform operating characteristics because the pressure detection characteristics of each pair of electrodes are the same as the characteristics of a common conductive rubber sheet used as a pressure sensor, and there are no moving parts. Therefore, a highly durable and highly reliable treadle can be obtained.

FIG. 8 shows an electrical equivalent circuit of a treadle in the case of a 3×4 matrix.

While supplying power to the electrodes 11-1.11-2 and 11-3 corresponding to the rows in a time-sharing manner, the electrodes 12-1.12-2.1 corresponding to the columns
By scanning 2-3° and 12-4 and sensing the electrodes at the matrix positions that are conductive, the coordinate position receiving the pressure can be determined.

In this way, a conductive rubber sheet whose resistance value changes when pressure is applied is used as a pressure sensor, and a plurality of pairs of electrodes are arranged in a matrix, and the single sheet is placed on top of these electrodes. Place the pressure sensor in the shape of
Since each set of electrodes is switched by changing the resistance value of the pressure sensor, the position receiving the pedal pressure from the wheel is one common pressure sensor, and the detection position of the pressure sensor is each electrode arranged in a matrix. As a result, the operating characteristics of each set of electrodes are determined by the characteristics of the pressure sensor used in common, and since there is little imbalance in sensitivity in each part of such a pressure sensor, sensitivity adjustment can also be done using the pressure sensor sheet. It can be done in units and each set of electrodes has uniform operating characteristics, and since there are no moving parts, it has good durability and reliability, and resolution can be easily increased by simply increasing the number of sets of electrodes. It is possible to provide a vehicle discrimination detector that has a simple configuration and is easy to maintain and adjust.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope of the gist thereof.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing a toll gate in an unmanned toll road system, Figure 2 is a plan view showing the configuration of the treadle, and Figure 3 a.
and b are a perspective view and an equivalent circuit diagram showing the configuration of a pressure sensor, FIG. 4 is a sectional view of a footboard, FIG. 5 is a sectional view showing an embodiment of the present invention, and FIGS. 6 a and b are according to the present invention. Exploded perspective view and electrode 1 for explaining the configuration of the insulating plate part of the treadle
Figure 7 is a schematic diagram to explain the operation of this device, Figure 8 is a 3x47
) FIG. 3 is a diagram showing an equivalent circuit of a treadle in the case of an IJ rack row. 8... Conductive rubber, 9... Insulating plate, 11
, 12... Electrode.

Claims (1)

[Scope of utility model registration request] A sheet of conductive rubber that changes the resistance of the pressurized part when pressure is applied is used as a pressure sensor, and multiple pairs of electrodes are arranged in an IJ rack shape, and the sheet-shaped sheet is placed on top of these electrodes. A vehicle discrimination detector characterized in that a pressure sensor is arranged, and each set of electrodes is switched according to a change in the resistance value of the pressure sensor.