JPS6342316B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a vehicle type discrimination device used for determining the type of vehicle entering a toll road toll gate or the like. [Prior Art] Generally, toll roads often use a toll system in which tolls vary depending on vehicle type, such as regular cars, large cars, and extra large cars. Additionally, on multi-section toll roads such as expressways, a small amount of tolls are collected for each section used. In such a toll road system, a toll ticket is issued at the entrance gate of the entrance interchange with necessary data such as the name and number of the entrance interchange, the date and time of entry, and the vehicle model code according to the above classification. and receive it at the exit gate of the exit interchange,
The data on the received pass is read by the reader of the processing device to determine the vehicle type-specific fare corresponding to the section to be used up to the exit interchange, and this is displayed, and the staff in charge collects the displayed fare from the user. It turns out. By the way, toll road operations must be carried out day and night, and as the toll road network continues to expand, a large number of attendants are required, so there is a desire for unmanned entrance and exit gates at toll road interchanges. . Therefore, as a method to make the entrance of the toll road system unmanned, the type of vehicle passing by, such as a regular car,
One possibility would be to automatically determine the type of vehicle, such as a large vehicle or an extra-large vehicle, and issue a ticket corresponding to the vehicle. Automatic identification of vehicle type is possible by measuring the width or tread of passing vehicles. This can be achieved by using ultrasonic waves or by installing a plurality of treadle switches at equal intervals in the width direction of the road surface. However, even if the vehicle type is determined by measuring the vehicle width or tread,
According to the car model classification (as of November 2017), there are some that cannot be identified. For example, there is a distinction between two-axle large trucks and large buses. That is, two-axle large trucks are classified as large vehicles, and large buses are classified as extra-large vehicles, and although the tolls differ, the two vehicles often have the same width and tread, and cannot be distinguished using the above-mentioned discrimination method. Therefore, in order to distinguish between such large trucks and large buses, conventional vehicle type discrimination devices
As a method, we perform vehicle body detection and axle detection,
As shown by A in Fig. 1, the first axis is The second method is to detect the overhang length from the top and determine the presence or absence of a gap between the driver's cab and the loading platform as shown by B in Figure 1 (there is one in trucks, but not in buses). ), and a third method is to determine the presence or absence of irregularities on the lower part of the vehicle body when viewed from the side (trucks have it, but buses do not), as shown by C in Figure 1. The fourth method is to position the engine as shown by D in Figure 1 (in the case of a truck, the engine is located at the front for the purpose of loading luggage, so that the loading area can be increased, and for buses, the engine is located at the front for the purpose of loading passengers, etc.). The engine position is located at the rear). [Problems to be Solved by the Invention] However, none of these methods can be said to be a reliable method since it is impossible to distinguish under the following circumstances. That is, in the first method, since the optical path is detected optically based on the shielding state of the optical path, when a vehicle is in a traffic jam, the rear of the preceding vehicle is covered by the phototube for overhang detection, making it impossible to distinguish. The second method also uses optical detection, and if the gap between the driver's seat and the cargo bed is stuffed with a cargo canopy or snow accumulates, the gap disappears and no light passes through. Since it cannot be photoelectrically detected, discrimination becomes impossible. Similarly, the third method uses optical detection, and if snow or mud accumulates at the bottom of the truck, the light path that should be obtained from the shape of the bottom of the truck will be blocked, so it can be distinguished from buses. I can't stand it. Furthermore, in the fourth method, sound and heat are detected to measure the position of the engine, but when there is traffic congestion, there is a possibility of erroneous measurements due to the influence of vehicles in front and behind. As described above, each method has advantages and disadvantages, but the reliability of vehicle type discrimination is not sufficient when it is necessary to distinguish between large buses and large trucks. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vehicle type discrimination device which has high reliability in vehicle type discrimination and can therefore accurately discriminate between trucks and buses. [Means for Solving the Problems] In order to achieve the above object, the present invention is configured as follows. That is, detecting the characteristics of the approaching vehicle,
Based on this, in a vehicle type discrimination device that discriminates the applicable vehicle type classification from a predetermined vehicle type classification and outputs vehicle type information, a light emitting/receiving device facing across the vehicle passageway is vertically directed across the lower and upper regions of the vehicle. a plurality of first phototube devices stacked on top of each other; and a plurality of first phototube devices that are buried in the vehicle passageway corresponding to the installation position of the first phototube device across the vehicle passageway, and that correspond to the width of the tread pressure action of the wheels of passing vehicles. a step board device that has a resistor that changes electrical resistance and detects the tread of the vehicle as an electrical signal based on the change in resistance; a second phototube device for overhang detection having a light emitter and receiver facing each other;
a gap detection circuit that operates according to the first detection signal of each passing vehicle outputted from the step board device and detects the presence or absence of a loading platform based on the signal of the upper area light receiver of the first phototube device; the first phototube device; A lower part missing detection circuit detects the shape of the lower part of the vehicle body based on the signal of the lower region light receiver, and an overhang detection circuit detects the overhang part based on the signal of the second phototube device, and is connected to each of these circuits and the step board device. It also includes a discrimination control circuit that discriminates the vehicle type based on each output signal and outputs a corresponding vehicle type discrimination signal. [Operation] In such a configuration, the vehicle is detected by the first phototube device, and the number of vehicle axles and the tread width are detected by the footplate device. Furthermore, the cargo platform detection circuit detects the presence or absence of a cargo platform based on the output of the upper area photoreceptor of the first phototube device, and the lower part omission detection circuit for detecting the shape of the lower part of the vehicle body uses the output of the lower area photoreceptor to detect the presence or absence of the cargo platform. Detect shapes. Furthermore, the overhang detection circuit detects the overhang of the passing vehicle based on the detection output of the lower shape and the light shielding signal from the second phototube device. Then, the vehicle type discrimination control circuit discriminates the vehicle type based on each of these detection outputs. In this device, the distinction between a truck and a bus is based on the difference in overhang length from the first axle, the gap between the driver's cab and the loading platform in the truck, and the gap between the first and second axles in the truck. The system detects features such as irregularities on the lower part of the vehicle body, and combines these detection results to make a comprehensive judgment.The system distinguishes between a truck and a bus based on differences in shape at multiple locations, making it accurate. It is possible to provide a vehicle type discrimination device that enables vehicle type discrimination. [Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 2 and 3.
This will be explained with reference to the figures. FIG. 2 is a block diagram showing an example of the configuration of this device. In the figure, 10 is a phototube device for detecting overhang, 20 is a phototube device for detecting the gap between the driver's cab and the loading platform, 30 is a phototube device for detecting a gap in the lower part of the vehicle body, and 50 is a phototube device for detecting when a vehicle is passing. This phototube device 50 is constructed by stacking a plurality of light emitters and receivers in the height direction at opposite positions across the vehicle passageway, and the paired light emitters and receivers are placed on the road surface. They are made to face each other via parallel optical paths, and by detecting interruptions in the optical paths, information on the side surface of the vehicle passing through the vehicle passageway is detected. Reference numeral 40 denotes a step board device for detecting the tread, tire width, axle, etc. laid down on the vehicle passing path at a position opposite to the phototube device 50, and is used here for detecting the tread and axle. The footboard device 40 is laid across almost the entire road in the transverse direction of the vehicle passageway, and has a pair of long resistance contacts, for example, rod-shaped, separated at the center of the vehicle passageway, as lower contacts, which are normally spaced apart from each other on the upper side. When it receives the pressure action of the wheel, the upper contact of the part that receives the action contacts the resistance contact and changes the resistance value, so that the pressure action is applied by the change in resistance value. Although the device is designed to detect the width, there are other types of tread pressure devices, such as those that have a large number of contacts arranged in a matrix and obtain information from the operating pattern of the contacts, and those that use a contact structure made of conductive rubber. The phototube device 10 for overhang detection consists of a pair of light emitters and receivers, and is located at a different location from the phototube device 50, for example, at a predetermined position ahead of the phototube device 50 in the traveling direction of the passing vehicle, across the vehicle passing path. The light receivers are installed facing each other, and when a passing vehicle passes, the optical path is interrupted and the detection output D ₁ is generated while the rear end of the vehicle passes over the front end of the vehicle.
This outputs the following. Reference numeral 11 denotes an overhang detection circuit, which latches (holds) the detection output _D1 of the phototube device 10 in synchronization with the first axis detection signal from the timing circuit 6, which will be described later. When the output signal is "0" and there is no light (track), an output signal _X1 of logic level "1" is output. As the phototube device 20 for detecting the gap between the driver's cab and the loading platform, a pair of light emitters and receivers located at the top of the phototube device 50 are used. It goes without saying that the height of this top step is lower than the roof of the bus and is high enough to detect the gap between the truck driver's cab and the cargo bed. Reference numeral 21 denotes a gap detection circuit that detects gaps based on the output of the phototube device 20. Measurement starts at the timing of the first axis output from the timing circuit 6, ends at the timing of the second axis, and continues between the two timings. When a gap is detected, a logic level "1" is output, and when a gap is not detected, a logic level "0" is output as an output signal _X2 . The phototube device 30 for detecting the lower part missing uses one or two pairs of light emitters and receivers located at appropriate heights at the bottom of the phototube device 50, and 31 is a timing circuit based on the output of the phototube device 30. 6 is output from the detection timing of the first axis of the vehicle to the detection timing of the second axis of the vehicle, detection of the lower part is detected, and if the lower part is detected, the logic level is "1", and if it is not detected, the logic level is set to "1". This is a bottom omission detection circuit that outputs an output signal _X3 of level "0". 41 is an axis/tread length measurement circuit that generates a tread length measurement signal TR and an axis signal AX which is an axis detection output based on the output of the tread plate device 40; Measure the tread length based on the resistance value (number of operating contacts for multi-contact types). Reference numeral 51 denotes a passage detection circuit that receives the output of the photoreceptor group of the phototube device 50, detects that a vehicle is passing, and outputs a passage detection signal P. The timing circuit 6 receives this passage signal P. The axis signal AX output from the axis/tread length measuring circuit 41 is counted, and the first count determines the detection output AX ₁ of the first axis of the vehicle, and the second count determines the detection output AX 1 of the vehicle's first axis. This generates the second axis detection output AX ₂ . 7 receives the tread length measurement signal TR output from the axle/tread length measurement circuit 41, and determines whether the vehicle is a regular vehicle or a large vehicle or above based on the tread length information indicated by this signal. For example, when the setting value γ of the setting circuit 7a, which sets the tread length of a vehicle type that is a regular car, is greater than or equal to the setting value γ,
That is, this circuit outputs a control signal _G1 to start determining the type of bus or truck when the vehicle is a large vehicle or larger. 12 is a multiplication circuit that multiplies the output X ₁ from the overhang detection circuit 11 by a correction constant α ₁ given from a constant circuit 12a and outputs the result; 22 is a multiplication circuit that also supplies the gap detection signal X ₂ from the constant circuit 22a; A multiplication circuit that multiplies the constant α ₂ and outputs the result,
32 is a constant circuit 32 for the lower dropout detection signal _X3 .
This is a circuit that multiplies by a correction constant α ₃ given by a. 8 is an adder circuit that adds the output signals X ₁ , α ₁ , X ₂ α ₂ , and X ₃ α ₃ given from these multiplier circuits 12, 22, and 32, and its output Y is Y=X ₁ α ₁ +X ₂ α ₂ +X ₃ α ₃ . Reference numeral 9 denotes a comparison circuit that operates upon receiving the control signal G output from the discrimination circuit 7 and compares the output of the addition circuit 8, and a constant circuit 9a that outputs the output Y from the addition circuit 8 and a constant for discrimination comparison. When Yβ, the track identification signal is determined, and when Y<
When β, a bus identification signal is output. The operation of this apparatus having such a configuration will be explained with reference to FIG. The vehicle is a photocell device 50
When reaching the position, the optical paths of some of the light emitters and receivers are interrupted, and a detection output is generated from the receivers of the interrupted optical paths, and the passage detection circuit 5
given to 1. As a result, the passage detection circuit 51 generates a passage signal P as shown in FIG. 3a during the optical path interruption period. On the other hand, the phototube device 10 for overhang detection
When the front of the vehicle approaches the position, the phototube device 10 outputs an overhang detection signal _D1 as shown in FIG.
Give to 1. In addition, the phototube device 20 detects the lower part of the vehicle body as the vehicle passes, and generates a missing detection signal (d) _D3 , and the phototube device 20 detects the gap between the driver's cab and the loading platform, as shown in FIG. signal like c
D ₂ is output. As the vehicle progresses, when the wheel of the first axis presses the footboard device 40, the footboard device 40 is operated by the footpressure, and the contact closes to generate an operating output and change the resistance value (in the case of a resistance contact type). . As a result, the shaft/tread length measurement circuit 41 generates the shaft signal AX which is the shaft detection output when the contact is operated (the third
Figure e) The tread length measurement signal TR is supplied to the timing circuit 6 and the tread length is detected from the resistance value.
occurs. Upon receiving the axis signal AX of the first axis, the timing circuit 6 generates a signal AX1 and supplies it to the overhang detection circuit 11, the gap detection circuit 21, and the bottom omission detection circuit 31. As a result, each circuit 11, 21, 31 receives the output of each corresponding phototube device 10, 20, 30, circuit 11 latches the input, and the other circuit 2
1 and 31, when a rising signal is input, it is latched and output. Here, to explain with reference to Figure 3, there are parts of the time chart indicated by solid lines and dotted lines.
Among these, the solid line shows the case of a truck, and the dotted line shows the case of a bus. Therefore, in the case of a track, the overhang detection circuit 11 generates an output as shown by a solid line in FIG. In the case of a truck, when the vehicle advances and the driver's cab and loading platform come to the position of the photocell device 50, a detection signal as shown in FIG. 3c is obtained from the phototube device 20, and when the rising signal is input, this Gap detection circuit 2 that latches
1, a signal as shown in FIG. 3g is applied from this circuit 21 to the multiplier circuit 22 from the time of latching until the passing signal P disappears. As the loading platform advances further, the loading platform will pass through. Unlike a bus, there is a large empty area at the bottom of the loading platform, so this is detected by the phototube device 30, and its output (Fig. 3 d) is sent to the bottom missing detection circuit. 31 and an output as shown in FIG. The inputs of each multiplier circuit 12, 22, 32 are given at logic levels. Therefore, each multiplication circuit 12, 2
2 and 32 are multiplied by respective inputs by constants for correction given to each, and then given to and added by the adder circuit 8. Here, the determination circuit 7 to which the tread length measurement signal TR is input determines whether the vehicle is larger than a large vehicle or not based on the tread length measurement signal TR, and if the vehicle is larger than a large vehicle, the control signal G is compared. The comparison circuit 9 is activated by applying it to the circuit 9. Therefore, for large vehicles or larger, each multiplier circuit 12,
The added value Y of the outputs 22 and 32 is compared with the output β of the constant circuit 9a, and an output for determining whether it is a bus or a track is output based on the comparison result. This determination is performed based on the following discriminant. That is, a bus or a truck is determined under the following conditions: Y=X ₁ α ₁ +X ₂ α ₂ +X ₃ α ₃ Yβ: Truck; when Y<β: Bus. For discrimination, a method is used in which points are assigned to the detection output of each detection element and the total score is compared with a threshold value, so constants such as α ₁ , α ₂ , α ₃ , and β must be set appropriately. This makes it possible to eliminate the influence of erroneous detection of discrimination elements, and to perform highly accurate bus/truck discrimination. For example, by setting α ₁ =α ₂ =α ₃ =γ and β = 2γ, the influence of false positive detection of one discrimination element can be removed. Note that the determination is made based on Table 1 below.

[Table] The probability of misclassification is determined by assuming that the false detection rate of each discrimination element is P ₁ = P ₂ = P ₃ = a, and that the modes of misclassification all change from “1” to “0” (that is, if a truck is a bus) (false detection), the result will be as shown in Table 2.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a vehicle type discrimination device having excellent features such as being able to discriminate between buses and trucks with high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the difference in characteristics between a bus and a truck, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a time chart for explaining its operation. 6...Timing circuit, 7...Discrimination circuit, 7
a, 12a, 22a, 32a, 9a... Constant circuit, 8... Addition circuit, 9... Comparison circuit, 10, 2
0, 30, 50...Phototube device, 40...Treadboard device, 11...Overhang detection circuit, 21...
Gap detection circuit, 31... Bottom omission detection circuit, 1
2, 22, 32...Multiplication circuit.

Claims (1)

[Claims] 1. In a vehicle type discrimination device that detects the characteristics of an approaching vehicle, determines the applicable vehicle category from a predetermined vehicle category based on the characteristics, and outputs vehicle type information, a light emitter/receiver that faces across the vehicle passageway is placed under the vehicle. A plurality of first pairs stacked vertically over the area and the upper area
a photocell device, and a resistor that is buried across the vehicle passageway in the vehicle passageway corresponding to the installation position of the first photocell device and changes its electrical resistance in accordance with the width of the pressure applied by the wheels of the passing vehicle. a stepboard device that detects the tread of a vehicle as an electrical signal based on a resistance change; and a light emitter/receiver that is installed at a predetermined position ahead of the first phototube device in the traveling direction of the passing vehicle and faces across the vehicle passing path. a second phototube device for overhang detection, which is equipped with a second phototube device for overhang detection; a gap detection circuit that detects the presence or absence of the vehicle body, a lower part missing detection circuit that detects the shape of the lower part of the vehicle body based on the signal from the lower area receiver of the first phototube device, and a signal from the second phototube device to detect the overhang portion. an overhang detection circuit;
A vehicle type discriminating device comprising a discrimination control circuit connected to each of these circuits and the step board device to discriminate the vehicle type based on each output signal and output a corresponding vehicle type discrimination signal.