JPH0427600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle type identification device using a resistive contact type footboard.

Toll roads generally use a toll system in which tolls vary depending on vehicle type, such as regular cars, large cars, and extra large cars. In addition, on multi-section toll roads such as expressways, tolls determined for each section of use are collected.

In such a toll road system, at the entrance gate of the entrance interchange, the name and number of the entrance interchange, the date and time of entry,
Furthermore, a pass is issued with necessary data such as the vehicle model code according to the above classification, and this is received at the exit gate of the exit interchange, and the data on the received pass is read by the reader of the processing device. Then, the vehicle type-specific toll corresponding to the section of use up to the exit interchange is calculated, displayed, and the staff collects the displayed toll from the user.

However, toll road operations must be carried out throughout the day and night, and as the toll road network continues to expand, a large number of staff are required.Therefore, there is a desire for unmanned entrance and exit gates at toll road interchanges. There is.

As a way to make the entrance to this toll road system unmanned, the type of vehicle passing by (for example, regular car, large car, large car type) is automatically determined,
Consideration is being given to issuing a toll ticket equivalent to the vehicle in question.

As a parameter for automatically identifying the car model,
The idea is to measure the wheel distance (tread), tire width (for determining whether it is a double tire or single tire), number of axles, etc. of each passing vehicle, and to make a determination based on this information. Among these, One method of measuring wheel distance is, for example, a treadle type method that uses a resistance wire and a resistance contact that is placed opposite the resistance wire and has a resilient upper contact above the resistance wire.

The configuration of a treadle using this resistance contact is shown in Figure 1.
The principle of wheel distance measurement using this treadle is shown in Fig. 2.

Figure 1 shows an axle-wheel detection type treadle 10 with resistance contacts.
This figure shows the structure of the vehicle, which is installed with its longitudinal direction facing the transverse direction of the road surface. A in FIG. 1 shows a plan view, and 11 and 12 are resistance contacts, which measure the number of wheels, tread, and tire width of passing vehicles. These resistance contacts 11 and 12 are arranged in order in the direction of travel of the vehicle, one of which covers the left half of the road surface,
Further, 13 is a flat contact point, which measures the number of axes of passing vehicles. This flat contact 13 is the resistance contact 11, 12
Two sets are provided parallel to these between them, and these are arranged almost completely at the road intersection across the road surface. Additionally, flat contacts 13' having the same structure as the flat contact 13 are provided at the positions of the resistance contacts 11 and 12, respectively, so as to cover the remaining half of the road surface. These flat contacts 13, 13' are provided to determine whether the vehicle is moving forward or backward based on their operation patterns. 14 is a lead wire. 1b shows the structure of the resistance contacts 11 and 12, and 1
5 is an upper contact; 16 is a lower contact located below this upper contact 15, in which a plurality of short contacts of a predetermined size are arranged horizontally at equal intervals;
A fixed resistor 17 having the same resistance value is connected between each adjacent contact point 6 . The contact material is made of a material such as stainless steel, and when a vehicle passes by, the part of the upper contact 15 that receives tire pressure is elastically deformed, and the elastically deformed part contacts the lower contact 16, and only a circular part is formed. A short circuit occurs, and the resistance values at both ends of the lower contact 16 change. Figure 1c shows the structure of the flat contact 13, 18 is the upper contact, and 19 is the lower contact, which are made of a material such as stainless steel, and are elastically deformed when a vehicle passes by. Wake up and make contact.

In order to separate and detect each passing vehicle, the treadle is placed under the optical axis of a photoelectric vehicle separator, which has multiple pairs of emitters and receivers stacked vertically across the vehicle passageway. By using the output of the treadle obtained while the optical axis of the vehicle separator is cut off, information on the wheel width of a passing vehicle can be obtained so that it can be distinguished from information on other vehicles.

FIG. 2 is a diagram for explaining the operating principle of the wheel detection type treadle 10. In the figure, 21 and 23 are the upper contacts 15 of the resistance contacts mentioned above, and 22 and 24 are the lower contacts 16 and the fixed This shows a resistor 17, which will be referred to as a resistor from now on. The resistance contacts 11 and 12 are arranged at the predetermined positions mentioned above, and the resistance contacts 11 and 12 are a, b, and c, respectively.
It has terminals a', b', and c'. Of these, terminals a and a' are connected to one end of the upper contacts 21 and 23, b and b' are connected to one end of the resistors 22 and 24, and c and c' are connected to one end of the resistors 22 and 24. connected to the other end.

Here, the principle of measuring the number of wheels, wheel distance, and tire width of a passing vehicle using this axle wheel detection type step board 10 will be explained.

Now, a vehicle is equipped with a wheel A having a wheel length L and a tire width l.
Suppose that you approach the top and press the resistance contacts 11 and 12.

The resistance contact 11 is placed on the right side of the center of the vehicle passageway, which is the width of one lane, and the resistance contact 12 is placed on the left side, so the right wheel of the vehicle connects the resistance contact 11 with the resistance contact 11.
Further, the left wheel presses the resistance contact 12.

Then, in the resistive contact 11, the portion of the resistive contact body 21 that receives the pedal pressure is depressed downward and comes into contact with the resistive body 22 at the lower part. Similarly, the portion of the resistance contact 12 that receives pressure from the left wheel is depressed downward and comes into contact with the resistor 24 at the bottom.

Upper contact body 2 in these resistors 22 and 24
Distinguishing between contact areas and non-contact areas with 1 and 23, on the resistor 22 side, there is a contact area at the center with a width corresponding to the tire width l, and non-contact areas on both sides of the contact area. On the side of the body 24, a contact portion is formed in the center with a width corresponding to the tire width l, and non-contact portions are formed on both sides of the contact portion.

Among these, the resistor resistance values of the contact section corresponding to the tire width l are r ₂ and r ₅ , and the resistor resistance values of the non-contact sections on both sides are r ₁ r ₃ , r ₄ ,
If r ₆ , then the resistance value R ₁ ' between both terminals b, c and b', c' of each resistor 22, 24,
R ₂ ' is the resistance value of the short circuit section due to contact between the upper contact bodies 21 and 23 from these R ₁ and R ₂ , assuming that the original resistance values of the respective resistors 22 and 24 are R ₁ and R ₂ The resistance value after subtracting r ₂ and r ₅ , that is, R ₁ ′ = R ₁ − _{r 2} , R ₂ ′ = R ₂ − r ₅ , is the resistance value when receiving pedal pressure, respectively from R _1.
The resistance value changes from R ₁ ′ and R ₂ to R ₂ ′. By measuring and comparing the change in resistance value each time a vehicle passes a tire, the tire width of the vehicle can be measured.

On the other hand, terminals a, b and
The resistance value of each section a' and b' is the resistance value of the left side that does not contact the upper contact 21 on the resistance contact 11 side.
r ₁ , and on the resistance contact 12 side, the resistance value r ₆ of the right side portion not in contact with the upper contact 23 is shown.

As described above, the resistance contacts 11 and 12 are set at predetermined positions on the road surface where the vehicle passes along the transverse direction of the road surface, extending from the center toward the right and left road shoulders, respectively, and therefore between terminals a and b. The sum of the resistance and the resistance between terminals a' and b' is a value that is closely related to the wheel width of the vehicle. Therefore, resistive contact 1
If voltage is applied to terminals 1 and 12 and the resistance values between terminals a, b and a', b' are extracted and added as voltage signals, this added value will correspond to the wheel width, so from this, the wheel distance can be calculated. can be measured.

However, the actual change in voltage for tire position detection has various patterns as shown in FIG. 5, a ₁ , b ₁ , and c ₁ . FIG. 5 a ₁ shows a case where the vehicle enters at a nearly right angle to the direction in which the treadle is installed, and therefore simultaneously depresses the resistive contact and leaves at the same time, as shown in FIG. 2 to shoot r ₅ . Here, the voltage of 4V at _a1 is an example of the voltage corresponding to _r6 in FIG. In addition, Fig. _5b1 shows a state in which the tire enters at a nearly right angle, but the center part of the tire first hits the resistance contact, then spreads to both sides and finally passes through, leaving the center part intact. This is more likely to occur with tires that have a low profile. Figure 5 c ₁
is a case where the vehicle does not pass at right angles to the treadle, that is, when the vehicle approaches the tread at an angle; in this case, a high voltage is input and gradually decreases.

Due to these voltage changes, in the circuit that recognizes the tire position, this voltage value goes through a peak hold circuit that holds the maximum value, so there is no problem in the case of Figure 5 a ₁ , but in Figure 5 b ₁ and 5. In the case of Figure _c1 , a measurement error will occur.

As a result of the above, the measured value of the wheel distance may have an error of up to twice the tire width, which may cause misclassification when classifying vehicle types based on tread. Therefore, there is a need for a vehicle type identification device that can more accurately measure information related to wheel distance.

The present invention has been made in view of the above-mentioned circumstances, and includes a vehicle type discrimination device that discriminates the vehicle type using at least information related to the wheel width of a passing vehicle. A treadle device having a resistor arranged on the resistor to obtain a change in electrical resistance according to the width of the pedal pressure of a wheel of a passing vehicle on the resistor, thereby obtaining information such as the tire width and wheel width of the vehicle; The wheel width and tire width information obtained from this treadle device are added together, and the distance between the outer sides of the wheels is determined from the maximum value, and this is obtained as information related to the wheel width. When the maximum value is obtained by adding up the information of
Focusing on the fact that the maximum value of the additional information does not change even if the condition of the wheels changes, the maximum value of the additional information is used to obtain the distance between the outside wheels of the passing vehicle, and this is related to the wheel distance. To provide a vehicle type discriminating device capable of highly accurate vehicle type discrimination by outputting information and thereby always obtaining information related to correct wheel width.

FIG. 3 is a block diagram showing the configuration of the apparatus of the present invention. In the figure, reference numerals 11 and 12 are resistance contacts of the footboard 10 shown in FIG. 21 and 23 are the upper contact bodies of the resistance contacts 11 and 12, respectively, on the footboard;
2 and 24 are resistors. a, b, c, a', b',
C' is the terminal described in FIG. 2 at the resistance contacts 11 and 12, and 31, 32, 36, and 37 are resistance-voltage conversion circuits that convert resistance values into voltage values. 31 of these are connected between the terminals a and b,
Also, 32 is connected between c and b, 36 is connected between a' and b', and 37 is connected between c' and b', and the resistance value shown between each connected terminal is converted into a voltage value and output. do.
33 and 38 are circuits that add two voltage signals, and 33 of these circuits adds the output of the resistance-voltage conversion circuit 32 as well as the output of the resistance-voltage conversion circuit 31. Similarly to the output of the resistance-voltage conversion circuit 36, 38 is the resistance-voltage conversion circuit 3.
Perform addition with the output of 7. Reference numerals 34 and 39 are voltage change memory circuits for storing peak values of voltage changes; is connected to the adder circuit 38,
Upon receiving the output, the peak value is extracted and stored. 35 and 310 are analog-to-digital conversion circuits that convert analog signals to digital signals;
35 converts the output of 34, and 310 converts the output of 39 into a digital signal and outputs the converted signal.

311 is an arithmetic processing circuit that receives outputs from the analog-to-digital conversion circuits 35 and 310;
The wheel distance of a passing vehicle is calculated by taking into consideration the physical positions of the left and right resistance contacts that have received pedal pressure.

The wheel distance measurement value of this arithmetic processing circuit 311 is provided to a vehicle type discriminating means (not shown).

Next, the operation of this device having the above configuration will be explained. Although not shown, this device obtains passing period information for each passing vehicle from the output of the vehicle separator,
The wheel distance is measured using the output of the treadle 10 during that time.

That is, when a vehicle approaches the vehicle separator, the vehicle body quickly cuts off the optical axis of the vehicle separator. Then, the wheel steps on the treadle 10. Then, the upper contacts 21, 23 of the resistance contacts 11, 12
The wheel pressure position is depressed, and that part is the resistance element 2.
2 and 24, and the resistances of the respective contacting portions are shot and the resistance value changes. This change is caused by terminal a,
Resistor-voltage conversion circuits 31, 32, 36, and 37 connected to b, c, a', b', and c' convert them into voltage values, respectively.

That is, as mentioned above, between terminals a and b and a',
The total resistance value between terminals b' and terminals b' indicates wheel width information, and the resistance values between terminals b and c and between terminals b' and c' each indicate tire width information.

The outputs of the voltage value conversion control of these pieces of information are added by corresponding adder circuits 38 and 38, respectively, and sent to corresponding voltage change value storage circuits 34 and 39, where the peak values of voltage changes are stored. Ru.
This peak value is the analog-to-digital conversion circuit 3
5, 310, where it is digitized, and sent to an arithmetic processing circuit 311, where the wheel distance of the passing vehicle is calculated based on this digitized data, taking into consideration the physical positions of the left and right resistance contacts. .

Here, the reason why the wheel distance is determined by adding the wheel distance information and the tire width information will be explained in a little more detail.

FIG. 4 shows the situation when a tire presses the resistance contact on one side.
Su is an upper contact, S ₁ to _{S o} are lower contacts made to the dimensions of the minimum detection unit, and r is a fixed resistor with the same resistance value installed between each lower contact. a, b,
c indicates the terminals on the road shoulder side and the opposite side of the upper and lower contacts, respectively.

Also, Figure ₅ shows how various signal outputs appear depending on the condition of _{the tire} and the passing conditions. Also, a ₂ , b ₂ , and c ₂ are the resistance changes between the c terminal and the b terminal in the figure converted into voltage changes. Furthermore, a ₃ , b ₃ , c ₃ are a ₁ , a ₂ , b ₁ and
It is the sum of b ₂ , c ₁ and c ₂ . This voltage value is expressed as V, which is the voltage change corresponding to the fixed resistor r− in FIG.

Here, a case will be described in which a tire having a tire width equivalent to four contact points passes through a position centered on the lower contact point _s7 .

First, consider a passing state in which the upper contact Su contacts the lower contacts S ₅ to S ₉ simultaneously at the start of passing, and the upper contact Su separates from the lower contacts S ₅ to _{S 9} simultaneously at the end of passing. In this case, the change in the signal voltage at the tire position will be as shown in Figure _5a1 . This voltage waveform starts with a voltage of 4V representing the tire position _s5 and remains the same voltage of 4V until the end. On the other hand, the change in the signal voltage of the tire width is as shown in Figure 5 a2, and represents a constant voltage value of 4V from the start to the end of the step. The addition of this tire width voltage to the tire position voltage results in a waveform representing a constant voltage value of 8V as shown in Figure _5a3 .

Next, at the start of passing, the center of the tire first presses, and the upper contact Su contacts the lower contact S ₇ , then spreads to both sides, and then the lower contacts S ₆ , S ₈ , and the lower contacts S ₅ , S _9.
It comes into contact with all positions of the lower contact points _S5 to _S9 , and when it finishes passing, it leaves both sides of the tire (lower contact points _S5 , _S9 ), and finally the center (lower contact point _S7 ). Consider a transit state in which the In this case, the voltage change of the tire position signal will be as shown in FIG. _5b1 . That is, at first the voltage represents the lower contact S ₇ (6V) at the center of the tire, halfway through the voltage represents the lower contact S ₅ on the outside of the tire, it becomes 4V, and finally the voltage represents the lower contact S ₇ again, 6V. On the other hand, the voltage change of the tire width signal is as shown in Fig. _5b2 .
In other words, it gradually increases from the beginning of the step and reaches a maximum in the middle.
It becomes 4V and decreases thereafter. The sum of this tire width voltage and tire position voltage is Figure _5b3 , which is a voltage waveform with a maximum value of 8V in the middle.

Furthermore, if the passing tire does not proceed at right angles to the tread, but gradually approaches the shoulder of the road, the upper contact point S _u contacts the lower contact point S ₉ at the beginning of passing, and the lower contact points S ₈ , S ₇ , S ₆ , and S ₅ , the contact area expands in order and comes into contact with all of the lower contact points S ₅ to _{S 9} . At the end of the passage, the upper contact S _u separates from the lower contact S ₉ and the lower contact point S The contact area expands in the order of contacts S ₈ , S ₉ , S ₆ , and S ₅ until it comes into contact with all positions of the lower contacts S ₅ to _{S 9} , and at the end of the passage, the upper contact S _u separates from the lower contact S ₉ . Away, bottom contacts S ₈ , S ₉ ,
Consider a passing state in which passing is completed by leaving S ₆ and S ₅ in order. In this case, the voltage change of the tire position signal will be as shown in Fig. 5 _c1 . In other words, at first the voltage represents the lower contact S ₉ 8V on the center side of the lane, and the voltage gradually decreases, and then the voltage represents the lower contact S 9 8V on the road shoulder side of the tire.
S ₅ It becomes constant at a voltage representing 4V. On the other hand, the voltage change of the tire width signal is as shown in Fig. 5 _c2 . In other words, it gradually increases from the beginning of the step and reaches a maximum in the middle.
It becomes 4V and decreases after that. The sum of this tire width voltage and tire position voltage is Figure 5 c ₃ ,
At first, a voltage waveform of maximum 8V appears. If the vehicle passes diagonally toward the center of the lane, c ₁ , c ₂ , and c ₃ in FIG. 5 become symmetrical waveforms.

In this manner, it can be seen _that in the three types of passing directions, if _the conventional measurement method is used, the maximum values are different as shown in _FIG . However, Figure 5 shows the tire width added.
It can be seen that for a ₃ , b ₃ , and c ₃ , the maximum values are constant in all three cases, and no calculation error occurs for each pass. Here, Fig. 5 a ₃ , b ₃ ,
c ₃ is the position of the tire on the center side of the lane, and from the left and right positions, the distance on the inside of the tire is measured, but since the tire width is measured, add one tire width to this distance on the inside of the tire. Adding them together will give you the distance between the centers of the left and right tires (generally called the tread), and adding the two tire widths will give you the distance on the outside of the tires.

Therefore, by obtaining the distance between the outsides of the tires, it is possible to always obtain accurate tires regardless of the driving condition of the vehicle passing the tread plate device (whether it is going straight or crossing diagonally) or the condition of the tires. By obtaining outside distance information, it is possible to prevent the occurrence of errors that have been a problem in wheel distance measurement, and therefore, more accurate vehicle type can be achieved in vehicle type discrimination devices that use information related to wheel distance as an element for vehicle type discrimination. Be able to make a distinction.

As described in detail above, the present invention provides a vehicle type discrimination device that discriminates the vehicle type using at least information related to the wheel width of a passing vehicle, which is embedded in a vehicle passing path, and includes:
A resistor is arranged in the transverse direction of the vehicle passageway, and the electrical resistance changes in accordance with the width of the pressure applied by the wheels of the passing vehicle on the resistor, thereby changing the tire width, vehicle distance, etc. of the vehicle. a stepboard device for obtaining information;
The wheel width and tire width information obtained from this treadle device are added together, and the distance between the outer sides of the wheels is determined from the maximum value, and this is obtained as information related to the wheel width. When the maximum value is obtained by adding up the information of Focusing on the fact that the maximum value of the addition information does not change even if the addition information is different, the distance between the wheels of the passing vehicle is obtained using the maximum value of the addition information, and this is output as information related to the wheel distance. I decided to do this, so
This makes it possible to always obtain information related to the wheel width with high accuracy, regardless of the passing conditions of passing vehicles or the condition of the wheels, and therefore, it is possible to perform highly accurate vehicle type discrimination. A vehicle type discrimination device can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the configuration of the footboard device,
Figure 2 is a diagram for explaining its operating principle, Figure 3
The figure is a block diagram showing one embodiment of the present invention, FIG. 4 is a diagram for explaining the operating status of the resistance contact, and FIG.
The figure is a diagram showing the relationship between the output pattern obtained from the resistance contact and the addition pattern. 10...Treadboard device, 11, 12...Resistance contact,
21, 23... Upper contact, 22, 24... Resistor, 31, 32, 36, 37... Resistance-voltage conversion circuit, 33, 38... Addition circuit, 34, 39...
Voltage change value storage circuit, 35, 310...Analog-to-digital conversion circuit, 311...Arithmetic processing circuit.

Claims (1)

[Scope of Claims] 1. A vehicle type discrimination device that discriminates the vehicle type using at least information related to the wheel length of a passing vehicle, which includes a resistor buried in a vehicle passing path and arranged in a transverse direction of the vehicle passing path. A treadle device that obtains electrical resistance changes in accordance with the width of the tread pressure action of the wheels of a passing vehicle with respect to this resistor, and thereby obtains information such as the tire width and wheel width of the vehicle; A vehicle type discriminating device comprising means for adding information on wheel width and tire width, determining the distance between the outer sides of the wheels from the maximum value thereof, and obtaining this as information related to the wheel width.