JP2014059807A - Vehicle axle number detector and vehicle type discrimination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle axle number detector and a vehicle type discrimination device which can accurately operate axle number detection even when the detection level of a step board is deteriorated, and realize longer life of the step board.SOLUTION: A vehicle axle number detector comprises: a step board embedded in a road allowing a vehicle to travel thereon; first determination means which determines whether or not the detection level of a step board is an ON threshold or more; second determination means which determines whether or not the detection level is between the ON threshold and an OFF threshold when the detection level is below the ON threshold in the determination result of the first determination means; threshold update means which updates the ON threshold and the Off threshold on the basis of a detection level when the detection level is between the ON threshold and the OFF threshold in the determination result of the second determination means; abnormality notification means which notifies of abnormality when the detection level is not between the ON threshold and the OFF threshold in the determination result of the second determination means; and axle number counting means which counts up an axle counter when the detection level is the ON threshold or more in the determination result of the first determination means or between the ON threshold and the OFF threshold in the determination result of the second determination means.

Description

  Embodiments described herein relate generally to a vehicle axis number detection device that detects the number of axes of a vehicle traveling on a road, and a vehicle type determination device that determines the vehicle type of the vehicle using the axis number detection device.

  Generally, an ETC system (ETC: registered trademark) is used in a toll gate such as an exclusive road for a toll road, a lane control device installed on a toll collection lane side, and an ETC card (to pay a fee) installed on the vehicle side. A system that automatically collects usage charges in a non-stop manner for vehicles by performing wireless communication with an on-board device equipped with an IC card) via an antenna installed on the toll collection lane It is.

  In this type of ETC system, at the entrance toll gate for entering the toll road, the lane control device to the toll gate by wireless communication between the vehicle-mounted device mounted on the vehicle and the lane control device installed on the toll collection lane side. Entrance information such as number and entrance passage time is transmitted to the vehicle-mounted device and written to the ETC card set in the vehicle-mounted device.

  In general, on toll roads, the toll differs depending on the vehicle type decided by the road operator in advance, so the vehicle type discriminating device installed on the toll collection lane side performs detailed vehicle type discrimination, and the vehicle type information that is the discrimination result is displayed. It is transmitted from the lane control device to the vehicle-mounted device and written on the ETC card.

  By the way, the vehicle type discriminating device is connected to an axle number detection device, an infrared sensor, etc., and the vehicle passes through these positions, so that the number of axles of the vehicle, the vehicle length, the vehicle width, the vehicle height, the presence or absence of traction. Etc., and the vehicle type is discriminated based on the identification result.

  2. Description of the Related Art Conventionally, as a number-of-axis detecting device used in such a vehicle type discriminating device, a device in which a tread board (pressure sensor) is embedded in a road surface and a traveling vehicle directly detects the number of axes by stepping on the tread board is known. .

  In general, the tread is made of rubber, and the resistance value changes due to pressurization when the wheel of a traveling vehicle is stepped on, and it is determined whether or not the wheel has passed due to the change in the resistance value. However, since the tread is made of rubber, there is a problem that even if the wheel passes due to bending or aging deterioration, there is little change in the resistance value, so that the detection level is lowered, and as a result, the number of axes cannot be detected accurately.

JP 2003-187375 A

  The problem to be solved by the present invention is to provide a vehicle axis number detecting device and a vehicle type discriminating device capable of accurately detecting the number of axes even if the detection level of the tread plate is lowered and extending the life of the tread plate. It is to be.

  The number-of-axes detection device for a vehicle according to the embodiment detects an impedance that is embedded in a road on which the vehicle travels so as to extend in the width direction and changes due to pressurization when stepped on a wheel of the traveling vehicle. As a result of the determination by the first determination means, the first determination means for determining whether or not the detection level output from the tread is greater than or equal to a preset ON threshold, A second determination unit that determines whether the detection level is between the on-threshold value and an off-threshold value that is lower than the on-threshold value that is set in advance, and the second determination unit, If the detection level is between the on-threshold value and the off-threshold value as a result of the determination by the threshold value, threshold value updating means for updating the on-threshold value and off-threshold value to new values based on the detection level, As a result of the determination by the second determination means, if the detection level is not between the on threshold value and the off threshold value, an abnormality notification means for notifying abnormality, and a result of the determination by the first determination means, the detection level A shaft number counting unit that counts up an axle counter when the detection level is between an on threshold value and an off threshold value as a result of determination by the second determination unit. ing.

The schematic diagram which shows roughly the structure of the vehicle type discrimination | determination apparatus containing the axle | axis number detection apparatus of the vehicle which concerns on embodiment. The figure explaining the detection level and threshold value of a tread according to an embodiment. The figure which shows the specific example of the set threshold value which concerns on embodiment. The flowchart explaining the operation | movement which concerns on embodiment.

Hereinafter, a vehicle type identification device including a vehicle axle number detection device according to an embodiment will be described with reference to the drawings.
FIG. 1 schematically shows the configuration of a vehicle type discriminating apparatus including a vehicle axis number detecting apparatus according to an embodiment. In FIG. 1, for example, a vehicle 12 entering the lane 11 is detected on both sides of a toll collection lane (road) 11 of an entrance toll gate for entering a toll road such as a highway from a general road. A light projecting portion 13a and a light receiving portion 13b of a vehicle detector 13 as vehicle detecting means are arranged opposite to each other.

  A tread (pressure-sensitive sensor) 14 is embedded in a portion of the toll collection lane 11 corresponding to the vehicle detector 13 so as to extend in the width direction of the lane 11. The tread 14 changes its resistance value (impedance) due to pressurization when it is stepped on the wheels of the traveling vehicle 12, and the change in the resistance value is output as a wheel passage detection signal.

  The output signal of the tread board 14 is sent to the axis number counter 15. The shaft number counting unit 15 counts the number of shafts of the vehicle 12 through a determination process described later based on the output signal of the tread board 14, and includes an axle counter 16. The result of counting the number of axes by the number-of-axis counting unit 15 is sent to the vehicle type determining unit 17.

  Here, the threshold value set as the initial setting value in advance will be described. As shown in FIG. 2, a first on threshold value and a second on threshold value at which the tread board 14 is turned on (wheel detection state) and an off threshold value at which the tread board 14 is turned off (wheel non-detection state) are set. As is clear from FIG. 2, the second on threshold is a value lower than the first on threshold (large value in terms of resistance value), and the off threshold is a value lower than the second on threshold. (A large value in terms of resistance value). FIG. 3 shows a specific example of the set value.

  Next, the operation of such a configuration will be described with reference to the flowchart shown in FIG.

  When the vehicle 12 enters the toll collection lane 11 and the vehicle detector 13 detects it (step S1), the axle number counting unit 15 checks the output of the tread plate 14 so that the wheels of the vehicle 12 move the tread plate 14. After confirming that it has been stepped on (step S2), it is determined whether or not the detection level of the tread board 14 is equal to or higher than a second ON threshold value set in advance (step S3).

  As a result of the determination, if the detection level of the tread board 14 is equal to or higher than the second on threshold, the axis number counting unit 15 determines whether or not the detection level of the tread 14 is equal to or higher than a first on threshold set in advance ( Step S4).

  As a result of the determination in step S4, the axis number counting unit 15 proceeds to step S5 if the detection level of the tread board 14 is equal to or higher than the first on threshold, and if the detection level of the tread board 14 is not equal to or higher than the first on threshold, In this case, since the detection level of the tread board 14 is between the first on-threshold value and the second on-threshold value, an alarm is output that warns that the detection level has decreased (step S6), and the process proceeds to step S5. .

  As a result of the determination in step S3, when the detection level of the tread board 14 is not equal to or higher than the second on threshold value, the shaft number counting unit 15 determines whether the detection level of the tread board 14 is between the second on threshold value and the off threshold value. Is determined (step S7).

  If the detection level of the tread board 14 is not between the second on threshold value and the off threshold value as a result of the determination in step S7, the axis number counting unit 15 is not more than the off threshold value in this case. Then, an abnormal alarm is output (step S8), and the process ends.

  As a result of the determination in step S7, when the detection level of the tread board 14 is between the second on threshold value and the off threshold value, the axis number counting unit 15 determines the first on threshold value and the second on threshold value based on the detection level. The threshold value and the off threshold value are updated to new values (step S9), and the process proceeds to step S5.

  Specifically, referring to the specific example of FIG. 3, in FIG. 3, the initial setting values are “first on threshold = 100”, “second on threshold = 200”, and “off threshold = 250”. In this case, since the detection level of the tread 14 is between the second on threshold (200) and the off threshold (250), the detection level is between the first on threshold and the second on threshold. Each threshold is automatically updated to enter. For example, the first ON threshold is “−50” with respect to the initial setting value “100” to “100−50 = 50”, and the second ON threshold is “+50” with respect to the initial setting value “200”. “200 + 50 = 250” is set, and the off threshold is “+100” with respect to the initial setting value “250” to be “250 + 100 = 350”.

  In step S5, the axle counter 16 is incremented by "+1", and the process proceeds to step S10. In step S10, it is checked whether or not the vehicle detector 13 detects the vehicle 12. If the vehicle 12 is detected, the process returns to step S2 and the same operation as described above is repeated.

  In step S10, when the vehicle detector 13 does not detect the vehicle 12, the shaft number counting unit 15 sends the count content of the axle counter 16 to the vehicle type determining unit 17 as the detected number of shafts (step S11).

  The vehicle type discriminating unit 17 discriminates the vehicle type of the vehicle 12 based on the detected number of axes (step S12). For example, when the detected number of axes is two, the vehicle 12 is determined to be a normal passenger car, and when the detected number of axes is three, the vehicle 12 is determined to be a truck. In addition to the number of axles, other vehicle type determination elements (for example, vehicle length, vehicle width, vehicle height, presence / absence of traction, etc.) are often used for determining the vehicle type. The vehicle type discrimination result is sent to the ETC system.

  As described above, the threshold values that are turned on (first on threshold value and second on threshold value) and the off threshold value that is turned off are set as initial setting values in advance. When the vehicle 12 passes over the tread board 14, if the detection level exceeds the first ON threshold, the axle count is normally performed. When the detection level falls between the second on-threshold value and the first on-threshold value, an alarm output indicating a decrease in the detection level is performed, but the axle count is performed normally. When the detection level falls below the second ON threshold, the axle alarm is not counted and an abnormal alarm is output. When the detection level falls between the second on-threshold and the second on-threshold, the threshold is automatically set so that the detection level falls between the first on-threshold and the second on-threshold. , Second on threshold value, off threshold value).

  As shown in FIG. 3, an allowable minimum value of the second ON threshold value may be set, and an abnormal alarm may be output when the detection level falls below this minimum value.

  According to the vehicle axis number detection device and the vehicle type identification device of at least one embodiment described above, when the detection level of the tread is lowered, the on-threshold is automatically changed according to the detection level. Even if the detection level is lowered, the number of axes can be accurately detected, and the life of the tread can be extended.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 11 ... Toll collection lane (road), 12 ... Vehicle, 13 ... Vehicle detector, 14 ... Tread board, 15 ... Axis number counting part, 16 ... Axle counter, 17 ... Vehicle type discrimination | determination part

Claims (4)

A tread that is embedded in the road on which the vehicle travels so as to extend in the width direction, and outputs an impedance that changes due to pressurization when stepped on a wheel of the traveling vehicle as a detection level;
First determination means for determining whether or not a detection level output from the tread is equal to or higher than a preset ON threshold;
As a result of the determination by the first determination means, if the detection level is not equal to or higher than the on threshold, it is determined whether the detection level is between the on threshold and an off threshold lower than the preset on threshold. A second determination means for determining;
As a result of the determination by the second determination means, when the detection level is between an on threshold value and an off threshold value, threshold value updating means for updating the on threshold value and the off threshold value to new values based on the detection level;
As a result of the determination by the second determination means, an abnormality notification means for notifying abnormality when the detection level is not between the on threshold value and the off threshold value;
As a result of determination by the first determination means, when the detection level is equal to or higher than an on threshold, or as a result of determination by the second determination means, the detection level is between an on threshold and an off threshold, Axis number counting means for counting up the axle counter,
A device for detecting the number of axles of a vehicle. Further comprising vehicle detection means provided in the vicinity of the tread board for detecting a vehicle entering the road;
2. The vehicle axis number detection device according to claim 1, wherein the axis number coefficient means counts up an axle counter while the vehicle detection means detects the vehicle.   The vehicle axis number detection device according to claim 1, wherein an allowable minimum value of the ON threshold value is set, and an abnormality is notified when the detection level falls below the minimum value. A tread that is embedded in the road on which the vehicle travels so as to extend in the width direction, and outputs an impedance that changes due to pressurization when stepped on a wheel of the traveling vehicle as a detection level;
First determination means for determining whether or not a detection level output from the tread is equal to or higher than a preset ON threshold;
As a result of the determination by the first determination means, if the detection level is not equal to or higher than the on threshold, it is determined whether the detection level is between the on threshold and an off threshold lower than the preset on threshold. A second determination means for determining;
As a result of the determination by the second determination means, when the detection level is between an on threshold value and an off threshold value, threshold value updating means for updating the on threshold value and the off threshold value to new values based on the detection level;
As a result of the determination by the second determination means, an abnormality notification means for notifying abnormality when the detection level is not between the on threshold value and the off threshold value;
As a result of determination by the first determination means, when the detection level is equal to or higher than an on threshold, or as a result of determination by the second determination means, the detection level is between an on threshold and an off threshold, Axis number counting means for counting up the axle counter,
Vehicle type discrimination means for discriminating the vehicle type of the vehicle based on the number of axes counted by the axis number coefficient means;
A vehicle type identification device comprising:

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