JPS6337438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle type discrimination device used, for example, in a toll collection system on a toll road.

Toll roads generally use different toll systems for different types of vehicles, such as regular cars and 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 toll gate of the entrance interchange, the entrance interchange code, entrance approach date, time,
Furthermore, a toll ticket is issued with necessary data such as the vehicle type code for the vehicle classification according to the above classification, received at the exit toll gate of the exit interchange, and the data on the received toll ticket is sent to the toll collection system. The reader reads the fare corresponding to the section to be used up to the exit interchange, displays it, and the staff collects the displayed fare from the user.

By the way, at the entrance/exit toll gate of a toll road, when issuing tickets or collecting tolls, a device that automatically discriminates the type of vehicle is used to determine whether the passing vehicle falls into a type such as a regular car, a large car, or an extra large car. The information is given to the toll collection system at the toll gate and used for ticket issuing and verification during toll calculation.

Automatic identification of vehicle type is possible by measuring the width, tread, length, weight, external shape, etc. of passing vehicles.

However, even if such measurement data is obtained, it may not be possible to accurately identify the vehicle type.

For example, according to the current classification of vehicle types in Japan, large trucks are classified as large vehicles, and large buses are classified as extra large vehicles, but depending on the loading status of large trucks, there is no difference in measurement data from large buses. In such a case, the vehicle will be mistakenly judged to be an oversized vehicle.

The present invention has been made in view of the above circumstances, and includes a vehicle detection device that detects a vehicle passing through a vehicle passageway and generates a vehicle detection signal, and a vehicle detection device that is installed near the installation position of the vehicle detection device and detects a vehicle passing through the vehicle passageway. A treadle device that generates an axle detection signal in response to wheel tread pressure, a device that is installed near the installation location of these devices and that detects running noise from passing vehicles, and a device that receives the detected output of this running noise and detects the detected output. A level detection device that generates an output when a predetermined level is exceeded, and a level detection device that receives the generated output of this level detection device, the vehicle detection signal, and the axle detection signal, and is based on axle information obtained from the axle detection signal during the vehicle detection signal output period. We know the engine installation position of passing vehicles based on the relationship between the vehicle part information and the output generation timing of the level detection device.
It consists of a determination device that detects whether or not it is a large bus.The engine sound is the loudest noise among passing vehicles, and the engine installation position is completely different for large buses and large trucks. By focusing on these points and using these points, we can find out which area of the front or rear body part of the passing vehicle is currently located based on the axle detection signal during the vehicle detection signal period, and combine this with the detection output of running noise. By obtaining vehicle engine position information from the maximum noise detection output and determining whether it is a large bus or not, it is possible to distinguish between a large bus and a large truck, which may be difficult to distinguish depending on the situation. The purpose of the present invention is to provide a vehicle type discrimination device that enables vehicle type discrimination.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a layout diagram of the component devices of this device at a tollgate gate. In the figure, 1 is a vehicle passageway at the tollgate gate, and 2 is a large bus running on this vehicle passageway 1. Reference numeral 3 denotes a treadle device installed along the transverse direction on the road surface of the vehicle passageway 1, and this treadle device 3 has, for example, a large number of contact points arranged in a matrix, or a treadle plate device 3 that has a number of contact points arranged in a matrix, or a treadle plate device 3 that is arranged on the road surface of the vehicle passageway 1 in a transverse direction. This is a well-known device that uses resistive contacts that produce electrical resistance changes that correspond to width, and is operated by wheel pressure to measure tire width, tread, vehicle running direction, number of axles, etc.

Reference numeral 4 denotes a microphone which is a device for detecting engine sound, which is installed on the side of the vehicle passageway 1 on the road side or near the installation location of the step board device 3. It is installed so as to face almost perpendicular to the side surface, has unidirectionality, and has extremely narrow directivity angle characteristics.

Reference numeral 5 denotes a pair of vehicle detection devices that are provided facing each other across the vehicle passageway 1, and this vehicle detection device 5 includes a light projector that generates visible light or infrared light, and a light receiver that detects the light. This vehicle detecting device 5 is a vehicle detecting device that optically detects a vehicle body and is already in practical use, and this vehicle detecting device 5 is disposed on the roadside or near the installation location of the footboard device 3.

It should be noted that the vehicle detection device 5 only needs to be able to detect the passing of a vehicle, so it is not limited to an optical type, and may be an ultrasonic type, an electromagnetic induction type, a method using radio waves, or the like.

FIG. 2 is a block diagram showing the configuration of the signal processing system in the apparatus of the present invention. In the figure, 3 is the aforementioned footboard device, 4 is the aforementioned microphone, and 5 is the aforementioned vehicle detection device.

In the present invention, the tread plate device 3 only needs to be able to detect the axle passing timing of a passing vehicle, so only the tread pressure detection output is used as the axle detection signal.

6 is a waveform shaping circuit that shapes the output of the step board device 3; 7 is a counter circuit that is reset by the output of the vehicle detection device 5 and counts the output of the waveform shaping circuit 6; 8 is a counter circuit of the waveform shaping circuit 6; This is a time-limited signal generation circuit that operates based on the output and generates an output for a predetermined period of time, and is realized using a mono multivibrator or the like.

Reference numeral 9 denotes an amplifier circuit for amplifying the signal from the microphone 4, the gain of which can be adjusted as appropriate. 10 is a differentiating circuit which receives the output of this amplifier circuit 9 as an input and generates a differential output corresponding to the amount of change per unit time; 11 is this differentiating circuit 10
12 is an AND circuit that takes the output of the Schmitt circuit 11 and the output of the time limit signal generation circuit 8, and 13 is an AND circuit that takes the output of the Schmitt circuit 11 as an input and generates an output when this input exceeds a predetermined level. AND circuit 12 and the second of the counter circuit 7
An AND circuit which takes the output terminal of the bit 13 and each output of the vehicle detection device 5 as input and performs a logical product thereof; 14 indicates the output terminal of the AND circuit 13 and the first bit of the counter circuit 7, and the vehicle detection device 5; This is an AND circuit which takes each output of the device 5 as input and calculates the AND of these. Of these, the counter circuit 7 and AND circuits 13 and 14 constitute a determination device that generates an output for determining whether or not it is a bus, and the differentiation circuit 10 and Schmitt circuit 11 detect the level of the output of the microphone 4. It constitutes a level detection device for.

The device of the present invention focuses on the point where the noise of the engine part is mainly large among the running noise of the vehicle, and determines which part of the passing vehicle is where the loudest noise generating part is located, thereby knowing the position of the engine part. Then, the vehicle type is determined.

That is, it takes advantage of the fact that large trucks have engines installed at the front of the vehicle for loading purposes, and large buses have engines installed at the rear of the vehicle for passenger purposes.

Next, the operation of this device will be explained. When a vehicle is traveling and reaches the installation position of the footboard device 3, microphone 4, and vehicle detection device 5, vehicle detection, axle detection, and noise detection are performed by these.

Now, assuming that these footboard device 3, microphone 4, and vehicle detection device 5 are installed at approximately the same position, when the front end of the vehicle reaches the position of vehicle detection device 5, this vehicle detection device 5 A vehicle detection output is generated as shown in FIG. 3a, and this output continues to be generated until the rear end of the vehicle passes.

Next, when the wheel on the front axle of the vehicle reaches the position of the tread plate device 3 and presses it, an axle detection signal is output from the tread plate device 3 as shown in Fig. 3b, and then, by the pressure on the rear axle, the wheel detects the axle. The axle detection signal is output again. This axle detection signal is then applied to a waveform shaping circuit 6, where it is waveform-shaped and then applied to a counter circuit 7. When the counter circuit 7 receives the detection output of the vehicle detection device 5, it is reset and the count value becomes zero, and when the axle detection signal of the front axle is received, the counter circuit 7 counts "1". The output of the first bit becomes logic level "1". Then, when the axle detection signal of the rear axle is received, the counter circuit 7 counts "2", and the output of the first bit changes from the logic level "0", and the output of the second bit changes from the logic level "0". Changes to “1”. This situation is shown in Figures 3c and d. FIG. 3c shows the first bit, and FIG. 3d shows the second bit. Therefore, a count output of "1" in the counter circuit 7 indicates the first axis, and a count output of "2" indicates the second axis.

On the other hand, the output of the waveform shaping circuit 6 is also given to a time limit signal generating circuit 8, and the time limit signal generating circuit 8 generates a time limit signal having a predetermined time width every time the axle detection signal is input. This time-limited signal is set to an appropriate time width in consideration of the speed of the vehicle traveling on the vehicle passageway 1 so that the tire sounds of the front axle and the rear axle can be separated.

Now, if a large two-axle truck is traveling, a vehicle detection signal is output from the time when the front position of the vehicle body is detected until the rear end of the vehicle has passed, and the tread plate device 3
An axle detection signal is output every time an axle passes over the axle.

Then, when the vehicle passes the position of the microphone 4, the noise of the vehicle body part it is passing through is detected by the microphone 4, as shown in FIG. 3F.

The noise is mainly tire noise and engine noise.
Tire noise is generally much lower than engine noise. In the case of a truck, since the engine is located at the front, a high level of noise is detected before and after the front axle detection signal is detected, and when the rear axle passes, tire noise from the rear axle is detected. Ru.

This noise detection output is amplified to an appropriate level by an amplifier circuit 9, differentiated by a differentiator 10, and given to a Schmitt circuit 11, which causes the Schmitt circuit 11 to generate an output while exceeding a predetermined level.

Assuming that the predetermined level of the Schmitt circuit 11 is set to a level corresponding to the detected level of engine noise, this means that an output is obtained from the Schmitt circuit 11 when passing through the engine section, and the truck In this case, an output is obtained from the Schmitt circuit 11 only during the generation period of the time limit signal during the passing period of the front axle. This situation is shown in FIG. 3h.

Therefore, an output is generated from the AND circuit 12 which takes the output of the time limit signal generation circuit 8 and the output of the Schmitt circuit 11 and performs a logical product thereof, for a predetermined period from the time when the front axle passes.
3 and 14, respectively.

These AND circuits 13 and 14 are connected to the vehicle detection device 5.
The vehicle detection signal outputted by the vehicle detection signal and the output signal of the counter circuit 7 are input, and since the front axle has passed but before the rear axle has passed, the counter circuit 7 has a count value of "1". Therefore, only the AND circuit 14 which operates when the count value is "1" generates an output as shown in FIG. 31. At the time when the rear axle passes, tire noise is the main component, so no output is generated from the Schmitt circuit 11, and therefore, there is no output from the AND circuit 12, so neither of the AND circuits 13 and 14 produces an output.

On the other hand, in the case of a large bus, as shown in FIG. is not generated and therefore there is no output from AND circuit 12, so neither AND circuits 13 and 14 generate an output.

However, during the time limit signal generation period after the detection of the rear axle, the detection output of the microphone 4 is at a high level due to engine sound detection, as shown in FIG. An output is generated as shown in FIG. 3I, and an output is generated from the gate circuit 12 that receives the output as shown by the dotted line in FIG. 3J.

On the other hand, the counter circuit 7 is activated by the detection output of the rear axle.
is counting "2", so when the counter circuit 7 is counting "2", the AND circuit 13 outputs an output as shown in FIG. 3k.

That is, T ₁ is the period from the initial generation of the vehicle detection signal (Fig. 3 a) until the first axle passes;
T ₂ is the time until the next axle passes, and T ₃ is the period until the vehicle detection signal disappears after the period T ₂ has passed.
Then, for a truck with the engine at the front, T ₂
The engine sound is detected during the period T 3, and in the case of a bus with the engine at the rear, the engine sound is detected during the period T ₃ , and as a result, in the case of a truck, the AND circuit 1
4, in the case of a bus, an output is obtained from the AND circuit 13, so the output of the AND circuit 14 can be used as a non-large bus determination signal, and the output of the AND circuit 13 can be used as a large bus determination signal.

As can be seen from the time chart, in the case of a large bus, the output from the AND circuit 13 is generated with a delay of _T2 hours after the detection of the front axle. This is especially true when you consider that although the speed of each vehicle at the tollgate gate is not constant, it is almost within the prescribed speed, and that the lengths between the front and rear axles of large trucks and large buses are similar. The shortest T ₂ that can be obtained can be assumed, and if the output timing of the Schmitt circuit 11 is monitored by time management after the vehicle is detected, it can be determined that the bus is a large bus if the output of the Schmitt circuit 11 occurs relatively late. In this case, the footboard device 3 becomes unnecessary.

In addition, in a multi-axle truck where two axles are placed close to each other on the front axle side, the engine may be located at the position of the two axles. , tread, vehicle width,
Since vehicle length, weight, etc. are detected and used as data for vehicle type identification, and multi-axle vehicles with large weights are classified as oversized vehicles, the same as large buses, it is difficult to distinguish a large two-axle truck from a large bus. It's good if possible.

As described in detail above, the present invention includes a vehicle detection device that detects a vehicle passing through a vehicle passageway and generates a vehicle detection signal, and a vehicle detection device that is installed near the installation position of the vehicle detection device and receives wheel pressure from passing vehicles. a treadle device that generates an axle detection signal, a device that is installed near the installation location of these devices and detects the running noise of passing vehicles, and a device that receives the detected output of this running noise and detects when the detected output exceeds a predetermined level. a level detection device that generates an output; and vehicle part information based on axle information obtained from the axle detection signal during the vehicle detection signal output period by receiving the generated output of the level detection device, the vehicle detection signal, and the axle detection signal. and a determination device that detects the engine installation position of a passing vehicle based on the output generation timing relationship of the level detection device and detects whether or not the vehicle is a large bus. Focusing on the maximum noise level, and taking advantage of the fact that the engines of large trucks and large buses are installed in completely different locations, the current body part of the passing vehicle is determined based on the axle detection signal during the vehicle detection signal period. By knowing which area it is, and using this information and the maximum noise detection output of the running noise detection output, we can obtain vehicle engine position information and use this to determine whether or not it is a large bus. It is possible to provide a vehicle type identification device that is simple in structure and accurate, such as being able to accurately identify large buses and large trucks, which are difficult to distinguish.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the arrangement of component equipment near the toll gate location of the present invention, FIG. 2 is a block diagram showing the main configuration of the present invention, and FIG. 3 is for explaining the operation of the block in FIG. 2. This is a time chart. DESCRIPTION OF SYMBOLS 1... Vehicle passageway, 3... Step board device, 4... Microphone, 5... Vehicle detection device, 6... Waveform shaping circuit, 7... Counter circuit, 8... Time limit signal generation circuit, 10... Differentiation Circuit, 11... Schmitt circuit, 12, 13, 14... AND circuit.

Claims (1)

[Claims] 1. A vehicle detection device 5 that detects a vehicle passing through a vehicle passageway and generates a vehicle detection signal;
A step board device 3 that generates an axle detection signal in response to the wheel pressure of a passing vehicle; a device 4 that is installed near the installation location of these devices and detects the running noise of the passing vehicle; and a device 4 that receives the detection output of this running noise. , level detection devices 10 and 11 that generate an output when the detection output exceeds a predetermined level; and receiving the generated output of the level detection device, the vehicle detection signal, and the axle detection signal, and detecting the axle during the vehicle detection signal output period. Judgment devices 7, 13, which know the engine installation position of a passing vehicle based on the relationship between the vehicle part information based on the axis information obtained from the signal and the output generation timing of the level detection device, and detect from this whether or not it is a large bus. 14. A vehicle type discrimination device comprising: 14.