JPS6244320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for identifying types of buses and trucks, which is necessary at toll collection stations on motorways, traffic survey locations, and the like.

The toll classifications on toll roads are divided into "regular vehicles,""largevehicles," and "extra large vehicles," so it is necessary to distinguish between these vehicle types. To distinguish between "regular cars" and "large cars," the number of axles, number of wheels,
Many devices have already been proposed that focus on differences in tread, which is the distance between the centers of left and right tires, and measure these to determine the difference (for example, see Japanese Patent Laid-Open No. 19051/1983). However, it is difficult to distinguish between "large vehicles" and "extra-large vehicles" because the classification principle described above may not hold, and in particular buses other than route buses are classified as "extra-large vehicles." This makes it difficult to distinguish between "large vehicles" and "extra-large vehicles." However, focusing on the fact that buses are the only vehicles that can be classified as "extra-large vehicles" even though they have two axles, we first use conventional technology to identify two-axle vehicles, and then conduct further tests such as tread measurement. With the conventional technology, if a "regular car" is identified and removed from among the two-axle vehicles, then if a bus is identified from the remaining vehicles, it becomes an extra-large vehicle. In other words, the problem to be solved is how to distinguish between buses and trucks. The present invention relates to a method for distinguishing between buses and trucks, which is necessary due to the above-mentioned circumstances.

FIG. 1 is a conceptual diagram showing an example of a conventional bus discrimination method, in which a is a top view of the entire system and b is a side view of the entire system. In the figure, 1 is a bus, 2 is an ultrasonic sensor consisting of an ultrasonic transmitting element and a receiving element, and 3 is an installation pole to which the ultrasonic sensor 2 is attached.

The bus identification method shown in the figure involves installing one or two ultrasonic sensors 2 on an installation pole 3 at a height similar to the roof of the bus 1, and measuring the height and length of the traveling vehicle. However, there are the following problems.

(b) A truck 4 (for example, a vehicle loaded with a freezer container) having the same height and length as a bus is incorrectly determined to be a bus.

(b) When two ultrasonic sensors are used, two installation poles are required, which increases the installation cost.

(c) When using one ultrasonic sensor, accurate determination is difficult due to the influence of vehicle speed.

Another conventional example is the bus discrimination method using the silhouette method shown in FIG.

In FIG. 2, 4 is a reflective photoelectric switch; 5 is a reflective photoelectric switch;
6 is a reflector, 6 is a vehicle speed detector, and 7 is a determination control device. The bus determination method shown in FIG. 2 uses a photoelectric switch group consisting of a large number of photoelectric switches 4 and a vehicle speed detector 6.
This method involves creating a silhouette of a vehicle passing between the vehicle and comparing the silhouette with a standard silhouette, but this method has the following problems.

(b) It requires a vehicle speed detector, making it an expensive system.

(b) It requires a large amount of memory, such as a memory for the running vehicle's silhouette and a memory for the standard vehicle silhouette, making the judgment control device expensive.

This invention was made in order to solve the problems in the prior art as described above, and therefore, the purpose of this invention is to provide a method for identifying bus and truck types with high determination accuracy and low cost. It is in.

The key point of this invention is to develop a bus and truck system that determines whether a passing vehicle is a bus or a truck, with the number of axles being two and the tread being determined to be that of a large vehicle. In the vehicle type discrimination method described above, a plurality of light emitters and light receivers are attached correspondingly along the height direction to each of a light emitting tower and a light receiving tower installed across the road surface of the vehicle to be discriminated. Multiple light beams are formed from a light emitter to a light receiver, and the front axle of a vehicle traveling on the road between the light emitting tower and the light receiving tower passes through the light beam position before the rear axle passes. During the first specific period of time, the number of times that the first light beam, which is located at a height of approximately 150 cm, turns on and off depending on the shape of the vehicle body among the plurality of light beams is counted. The count value is below,
65cm of the plurality of light beams during the first specific period (referred to as a first count value).
Multiple light beams (hereinafter referred to as the second beam) located at a height of
It detects as a signal the turning on and off of the light beams (referred to as the second light beam group) depending on the shape of the vehicle body, and detects the turning on and off of each light beam constituting the second light beam group.
A logical sum operation is performed between the OFF signals, and the number of times the resulting signal turns on and off is counted (the count value is hereinafter referred to as the second count value), and the rear axle of the vehicle is illuminated. In the second specific period from passing through the beam position until the traveling vehicle finishes passing through the light beam position, the second
The number of times each light beam constituting the light beam group turns on and off is counted, and the sum of these count values is calculated (hereinafter, the sum is referred to as the third count value). ), the first count value is equal to a certain first set value, the second count value is within a predetermined range with respect to the certain second set value, and further the second count value is equal to a certain first set value; The passing vehicle is determined to be a bus when the sum of the value and the third count value is within a predetermined range with respect to a certain third set value.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a perspective view showing a vehicle type discrimination system to which the present invention is implemented. In the figure, 11 is a running vehicle, 12 is a running road surface, 13 is a light emitting tower, 14 is a light receiving tower, 15 is a light emitter attached to the light emitting tower 13, 1
6 is a light receiver attached to the light receiving tower 14, and 17 is a conventionally known wheel information detection device buried in the road surface, which is made of pressure-sensitive conductive rubber, a resistor, etc. , the tread, etc., which is the distance between the centers of both the left and right tires (for an example, please refer to Japanese Patent Application Laid-open No. 1988-19051 if necessary). 19 is a control device provided near the light receiving tower 14, and 21 is a booth (tollgate). The light emitter 15 provided on the light emitting tower 13 and the light receiver 16 provided on the light receiving tower 14 correspond to each other, forming a light screen between them. In addition, a plurality of light emitters and light receivers are provided at appropriate height positions on each of the light receiving tower 14 and the light emitting tower 15, but this will be explained in detail later as it is related to the present invention.

Next, the operation will be explained. The traveling vehicle 11 is the luminous tower 1
Each unit is separated by blocking the optical screen formed by the light emitter 15 provided at the light receiving tower 14 and the light receiver 16 provided at the light receiving tower 14. Furthermore, the wheel information detection device 17 detects the number of axles and wheels of the traveling vehicle 11,
The tread and the like are measured, and using this information, the control device 19 distinguishes between a regular car, a large car, and an extra large car to a considerable degree by following the procedure shown in FIG.

Please refer to FIG. As mentioned above, since the wheel information detection device 17 has detected the number of axles, number of wheels, tread, etc. of the traveling vehicle 11, first, step 1 is performed.
In step 3, it is checked whether the number of axles of the vehicle is two, and if no, then in step 3 it is checked whether the number of axles is three. If YES, in step 3, it is checked whether the vehicle is a large car or not, and if YES, it is determined that it is a large car, and if NO, it is determined that it is a regular car. If it is determined in step 2 that the number of axes is not 3, step 4
Then, it is checked whether the number of axes is 4 or not. If yes, in step 5, it is checked whether the vehicle is oversized or not based on the number of wheels, etc., and if yes, it is an oversized vehicle.
If no, it will be determined that it is a large vehicle. If step 4 is NO, it means that it has 5 or more axles, so it is definitely determined to be an oversized vehicle.

On the other hand, if the answer is yes in step 1, it is checked in step 6 whether the vehicle is a large car or not. Buses are also included in large vehicles, and if they are buses, they must be re-judged as extra-large vehicles (the circumstances in between are due to the fee structure,
(as explained earlier). Therefore, the flowchart of the subsequent operations when the determination in step 6 is YES is shown again in FIG. 4A.

In FIG. 4A, there is a step 7 that asks whether the vehicle is a bus, and if YES, it is an oversized vehicle, and if NO, it is a truck, so it is determined that the vehicle is a large vehicle. This step 7
The vehicle type discrimination method using a light beam of the present invention is used as the discrimination method in .

From the above explanation, it is believed that the position occupied by the discrimination method according to the present invention in the overall vehicle type discrimination system has been understood, and therefore embodiments of the present invention will be specifically described below.

FIG. 5 is a conceptual diagram showing means for forming a screen using a light beam to explain an embodiment of the present invention.

In the same figure, a light emitting tower 13 has a large number of light emitters 1.
5 and the light receiving tower 14 are respectively provided with the same number of light receivers 16 corresponding to each other, and a light screen is formed by sending a light beam from each light emitter to each light receiver. When a vehicle passes through this light screen, a beam is created that is blocked by the vehicle body.
In the photoreceiver at this beam position, the previously on output changes to off. The blocked beam position is
Since it changes depending on the shape of the vehicle body, it is possible to determine the type of vehicle by checking the on/off status of the output of each light receiver.

Therefore, in order to distinguish between a bus and a truck, the output _R1 of a receiver located at a height of approximately 150 cm and the output of three receivers located at a height near the center position of the vehicle's tires (approximately 65 cm) are used. Using R ₂ , R ₃ , and R ₄ , how the outputs of buses and trucks change will be explained next. Note that the number of light receivers used is not limited to these.

FIG. 6 shows the output R ₁ when a vehicle passes
This is a timing chart mainly showing the waveform of ~ _R4 .

Refer to the same figure. First, when a vehicle enters the light screen (see FIGS. 3 and 5), an appropriate light receiver outputs a "vehicle present" signal A. On the other hand, every time the axle crosses the wheel information detection device 17 (Fig. 3), the detection device 17 outputs signals ``Axle present'' and ``forward/reverse'' signals B and C. As the vehicle travels, the output R ₁
~ _R4 changes as shown.

Next, the characteristics of the outputs R ₁ to _{R 4} when the running vehicles are buses and trucks and the discrimination between buses and trucks based on the characteristics will be described.

(1) Period t ₁ from when the “car present” signal is output until the first axis is detected 1 During this period, the waveform of output R ₁ is
Both tracks have waveforms as shown in the time chart of FIG. 6, and there is no significant difference. But the output R ₂
Regarding the waveform of ~ _R4 , as shown in the time chart in Figure 6, each output rises only once on the bus (according to experiments, this is the case with most buses, but Some buses not only rise, but also turn on and off when they fall). For tracks, output
As shown in R ₃ and R ₄ , it turns on and off (according to experiments, in some tracks, R ₃ and R ₄ only rise once, just like R ₂ ). In this way R ₁ ~ in period t _1
R4 output information is difficult to distinguish between buses and trucks, so it is not used.

(2) A certain first point along the direction of travel of the vehicle.
The waveform of the output R ₁ during this period is the first specific period t ₂ from, for example, the first axis as a specific part of , until the second axis, as the second specific part that follows, is detected. , the bus maintains the on output, and the track may once turn from on to off and then continue as shown by the dotted line, or it may further turn on and change. Therefore, as shown in Figure 7, the number of on/off times of output _R1 is calculated using counter A.
If you count and memorize it, you can easily distinguish between buses and trucks. For example, if the content of counter A is 0, it can be determined that it is a bus, and if it is 1 or more, it can be determined that it is a truck. However, in reality, it is known that some trucks are included among the vehicles classified as buses when A=0.

Regarding the waveforms of outputs R ₂ to _{R 4} , as shown in Figure 6, there is a difference in the number of on and off times between bus and truck, and this difference in number makes it possible to distinguish between bus and truck to some extent. However, it has been experimentally found that if the discrimination is made only based on this difference, a considerable number of trucks will be included in the vehicles determined to be buses.

Therefore, the OR output of outputs R ₂ to R ₄ in period t ₂ (it turns on when any one of outputs R ₂ to _{R 4} is off, and turns off when all of R ₂ to _{R 4} turn on) If RB is the output (output) for the bus, and RT is the output for the truck, the result will be as shown in FIG. The number of on/off times and RT of this OR output RB
As is clear from FIG. 6, there is a significant difference in the number of on and off times. Therefore, as shown in Fig. 7, if the logical sum of outputs R ₂ to _{R 4} is created using an OR circuit, and the number of times the logical sum output turns on and off is counted and stored in counter B, the bus and track can be controlled depending on the contents. can be determined. For example, if the content B of counter B is B≦2, then the bus, B>
If it is 2, it is determined that it is a truck. However, it has been experimentally found that the buses determined in this way still contain some trucks.

(3) A certain second point along the direction of travel of the vehicle.
The second axis, which is a specific part of
The waveform of _the output _R1 during this period is not available since there is no significant difference between bus and track.
Outputs R ₂ to _{R 4} are generally turned on and off more often in a truck than in a bus. However, some buses and trucks have similar on/off times. However, the period
At t ₂ , the content of counter B becomes B≦2, so a significant difference that is useful for identifying and removing some trucks included in the group of vehicles that are determined to be buses is determined. , the outputs of R ₂ to _{R 4} during period t ₃ are also for bus and track. That is, the output R ₂ in period t ₃
The number of times _R4 is turned on and turned off is counted and stored by counters X, Y, and Z, respectively, as shown in FIG. The sum of the counts of counters X, Y, and Z is determined and is set as S (S=X+Y+Z). Then, if S≦4, it is a bus, and if S>4, it is a truck, so that it is possible to completely distinguish between a bus and a truck by using the value of S.

Further, as shown in FIG. 7, at counter T, the sum of the contents of counter B and S (T=B+S=
B+X+Y+Z), and if T≦6, bus, T
>6, it can also be determined as a truck. It goes without saying that if the number of sensors (R ₂ to _{R 4} in this case) differs, the threshold value for distinguishing between a bus and a truck will change.

Discrimination between bus and track can be made in the above manner.Next, an explanation will be added regarding the counting and storage timing of the counters X, Y, and Z.
First, when the "car present" information (Figure 6 (a)) is received, counters X, Y, and Z start counting and memorizing, respectively, and if the "forward, reverse" information (Figure 6 (c)) is "forward", the counters After all the contents of X, Y, and Z are cleared, each counter counts and stores again using the information on the second axis (Figure 6 B), and the results are used to distinguish between buses and trucks as described above. . On the other hand, if the "forward, reverse" information is "reverse", the contents of the counters X, Y, and Z counted and stored according to the "car present" information are used as they are for the above-mentioned determination.

The above bus/truck discrimination procedure is shown in a flowchart in FIG. In the figure, first, vehicle detection, wheel number detection, axle number detection, and tread detection are performed using a conventional wheel information detection device (17 in FIG. 3). Next, in step 1, it is determined whether the vehicle in question is a two-axle vehicle or not based on the axle number detection information. If YES, in step 2, it is determined whether the vehicle is large or not using tread detection information or the like. If the answer is yes, we can finally move on to implementing the discrimination method according to the present invention, and proceed to step 3.
Distinguish between buses and trucks by following steps 6 to 6. The details of steps 3-6 are already clear and will not be repeated here.

In addition, in the present invention, as shown in FIG. 5, R ₂ ,
The above-mentioned discrimination is made possible by mainly using the R ₃ and R ₄ outputs, but this is because buses have a simple structure consisting mainly of flat side panels near the height position mentioned above. In trucks, in addition to the side plates,
This is because it has a relatively complex structure, with attachments (fuel tanks) and gaps, so differences in structure (shape) are utilized.
However, there are many different models of the same bus or truck, and their side structures are not uniform, so after repeated experiments, we were able to establish the above-mentioned method for distinguishing between buses and trucks. It is.

The present invention provides the following effects.

Not affected by cargo.

There is no need to measure the speed or length of the vehicle, resulting in an inexpensive configuration.

Compared to the conventional method, which uses silhouettes for comparison, only a counter is required as memory, which results in a cheaper configuration.

As is clear from the 8th flowchart in FIG. 4, it is possible to identify the vehicle type in accordance with the current toll road toll system.

According to this invention, by combining with the conventional technology, it is possible to easily separate each vehicle, detect the number of axles, detect the number of wheels, detect tread, and distinguish between buses and trucks. The present invention can be used in a wide range of applications such as general toll roads, toll parking lots, and other traffic surveys.

[Brief explanation of the drawing]

Fig. 1 is a conceptual diagram showing an example of a conventional bus identification method, Fig. 2 is a perspective view showing another example of the same conventional bus identification method, and Fig. 3 is a conceptual diagram showing an example of a conventional bus identification method. 4 is a flowchart showing the discrimination operation in the vehicle type discrimination method of FIG. 3, FIG. 4A is a detailed view of a part of the flowchart in FIG. 4, and FIG. 5 is an embodiment of the present invention. FIG. 6 is a conceptual diagram showing a means for forming a screen using a light beam to explain the above, and FIG. 6 is a timing chart mainly showing the waveforms of the outputs R ₁ to R ₄ when the vehicle passes through the light beam in FIG. FIG. 7 is a block diagram of a bus/track discrimination circuit used in carrying out the present invention, and FIG. 8 is a flowchart showing a bus/track discrimination procedure according to the present invention. Code explanation, 1...Bus, 2...Ultrasonic sensor,
3... Installation pole, 4... Reflective photoelectric switch, 5... Reflector, 6... Vehicle speed detector, 7...
...Judgment control device, 11... Traveling vehicle, 12... Road surface, 13... Light emitting tower, 14... Light receiving tower, 15...
Light emitter, 16... Light receiver, 17... Wheel information detection device.

Claims (1)

[Claims] 1. A bus and a truck that determines whether the vehicle is a bus or a truck, with a passing vehicle determined to have two axles and a tread of a large vehicle. In the truck vehicle type discrimination method, a plurality of light emitters 15 and light receivers 16 are installed along the height direction on each of a light emitting tower 13 and a light receiving tower 14 installed across the running road surface 12 of the vehicle to be discriminated. They are attached correspondingly to form a plurality of light beams from the light emitter 15 to the light receiver 16, and the front axle of the vehicle 11 running on the road surface 12 between the light emitting tower 13 and the light receiving tower 14 is connected to the light beam. During the first specific period t2 from passing through the position to passing the rear axle, approximately one of the plurality of light beams
Counting the number of times that the first light beam R1 located at a height of 150 cm turns on and off depending on the shape of the vehicle body (this count value is hereinafter referred to as the first count value), and the first identification is performed. During period t2, among the plurality of light beams, a plurality of light beams (R2, R3, R4, etc.) (hereinafter referred to as the second light beam group) located at a height of about 65 cm are used to detect the shape of the vehicle body. Detects as a signal whether the light beams turn on or off depending on The number of times the light beam is turned off is counted (the count value is hereinafter referred to as a second count value), and the number of times the vehicle 11 passes the light beam position is counted after the rear axle of the traveling vehicle 11 passes the light beam position. In the second specific period t3 until the end,
turning on and off each light beam constituting the second light beam group;
While counting the number of off times, the sum of these count values is taken (hereinafter, the sum is referred to as a third count value), and the first count value is equal to a certain first set value, and furthermore, the second count value is The count value is within a predetermined range with respect to a certain second set value, and the total of the second count value and the third count value is within a predetermined range with respect to a certain third set value. A method for discriminating vehicle types between buses and trucks, characterized in that the passing vehicle 11 is determined to be a bus when the passing vehicle 11 is within the range.