JP2017182740A - Axle number detector, axle number detection method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axle number detector, an axle number detection method and a program, capable of accurately detecting an axle number of a vehicle even when a vehicle enters a step board obliquely.SOLUTION: An axle number detector (1) comprises: a step board (20) which is installed in a lane width direction, and outputs a tire detection signal according to treading of tires of a vehicle which travels; a detection time information acquisition part (300) for acquiring detection time information which indicates a time when the tire detection signal is output; an axle determination part (301) for determining whether or not, two tire detection signals are tire detection signals caused by treading of two tires attached to a same axle of the vehicle, based on the detection time information; and an axle number identification part (302) for identifying the number of pairs of the two tire detection signals determined to be tire detection signals caused by treading of two tires attached to the same axle, as an axle number of the vehicle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an axle number detection device, an axle number detection method, and a program.

  Tollgates on toll roads such as expressways may be equipped with a vehicle type discriminating device that automatically discriminates the vehicle type of a passing vehicle in order to charge according to the vehicle type. Such a vehicle type discriminating device includes a vehicle detector that detects the entry of vehicles one by one, a tread that detects the number of axles of the vehicle by counting the number of steps by the tires of the vehicle (for example, Patent Document 1).

JP 2013-53882 A

  Regarding the tread used in the vehicle type discriminating device, when the vehicle enters obliquely with respect to the tread, the same tire is attached to one end of the same axle and the tire attached to the other end. The timing of stepping on the tread may be different. In this case, the number of times that the treadle was stepped separately on the tire attached to one end of the same axle and the tire attached to the other end is counted, and as a result, the number of axles of the vehicle May be detected by mistake (more than it actually is).

  The present invention has been made in view of such a problem, and even when the vehicle enters obliquely with respect to the tread, the number of axles detecting device and the number of axles capable of detecting the number of axles of the vehicle. A detection method and a program are provided.

In order to solve the above problems, the present invention employs the following means.
According to one aspect of the present invention, the axle number detection device (1) is installed in the lane width direction and outputs a tire detection signal in response to a tire tread of a traveling vehicle, and the tire detection Two tire detection signals are attached to the same axle of the vehicle based on the detection time information acquisition unit (300) that acquires detection time information indicating the time when the signal is output, and the detection time information. An axle determination unit (301) that determines whether or not the tire detection signal is due to the treading of two tires, and the two that are determined to be tire detection signals due to the treading of two tires attached to the same axle An axle number specifying unit (302) for specifying the number of pairs of tire detection signals as the number of axles of the vehicle.

  In this way, the axle determination unit determines whether or not the two tire detection signals out of the tire detection signals output from the treads are tire detection signals by stepping on two tires attached to the same axle. Is determined based on the detection time information of each tire detection signal. Thereby, even if the vehicle enters obliquely with respect to the tread, and two tires attached to the same axle step on the tread at different timings, the axle determination unit is based on the detection time information, It can be determined that the two tire detection signals output from the treadle at different timings are “tire detection signals by stepping on two tires attached to the same axle”. Accordingly, the axle number detection device can detect the number of axles while suppressing erroneous determination of the number of axles.

  According to one aspect of the present invention, the number-of-axle detection device is a detection position information acquisition unit (305) that acquires detection position information indicating a position where the tire is stepped in the lane width direction based on the tire detection signal. ), The detection time information, and the detection position information, for each of the tire detection signals, the first axis is a value based on the detection time information, and the second axis is a spatial width direction lane width direction. A coordinate information generation unit (306) that generates coordinate information indicating a position in the two-dimensional map (M, M ′) as a position, and two of the plurality of coordinate information are selected and combined. A vector information generation unit (307) that generates vector information. The axle determination unit is configured to detect the two tires related to the two pieces of coordinate information combined as the vector information based on the vector information having the same direction in the two-dimensional map among the plurality of vector information. It is determined that the signal is a tire detection signal generated by stepping on two tires attached to the same axle of the vehicle.

By doing in this way, the axle determination part is the direction in the two-dimensional map of one vector information among the several vector information which the vector information generation part produced | generated, and the direction in the two-dimensional map of other vector information If the two coincide with each other, it is determined that the two tire detection signals related to the two pieces of coordinate information combined as the one vector information are tire detection signals due to treading of two tires attached to the same axle.
Thus, the axle determination unit refers to the vector information in which the directions in the two-dimensional map coincide with each other even when the vehicle enters obliquely with respect to the tread, and which of the plurality of tire detection signals is It is possible to accurately determine whether the tire detection signal is due to the treading of two tires attached to the same axle.

  According to an aspect of the present invention, the vector information generation unit classifies the plurality of coordinate information into a first group and a second group based on the detected position information, and from the first group The vector information is generated by combining the selected coordinate information and the coordinate information selected from the second group.

  By doing in this way, the vector information generation unit, based on the detection position information, the coordinate information included in the two-dimensional map, the coordinate information of the tire detection signal due to the depression of the tire on one end side in the vehicle width direction, It can be classified into the coordinate information of the tire detection signal by stepping on the tire on the other end side. For this reason, the vector information generation unit can generate vector information by quickly and accurately selecting two coordinate information related to two tires attached to the same axle.

  According to an aspect of the present invention, the vector information generation unit is configured to perform the coordinate information one by one in the order of detection times indicated by the detection time information from each of the first group and the second group. Select.

  By doing in this way, the vector information generation part can generate vector information by selecting two coordinate information quickly. As a result, the processing speed of the axle number detection device can be improved.

  According to an aspect of the present invention, when there is coordinate information that cannot configure the vector information among the plurality of coordinate information, the vector information generation unit includes the detected position information of the coordinate information, Based on the number of coordinate information included in the two-dimensional map, it is determined whether or not the tire detection signal related to the coordinate information is a false detection.

In this way, the vector information generation unit, for example, has only one coordinate information in the two-dimensional map, and when the vector information cannot be configured by the coordinate information, the two-dimensional map travels on the lane. It is possible to determine that the tire detection signal related to the coordinate information is a false detection, assuming that the pattern is not a two-dimensional map pattern assumed from the vehicle.
Further, for example, when the coordinate information that cannot constitute the vector information is included in the two-dimensional map, the coordinate information included in the two-dimensional map is two, and the two coordinate information is the same. When the detected position information is included, the vector information generation unit can determine that the two-dimensional map indicates a two-dimensional map pattern of the two-wheeled vehicle.

  According to one aspect of the present invention, a method for detecting the number of axles includes a step of outputting a tire detection signal in response to depression of a tire of a traveling vehicle, and detection time information indicating a time at which the tire detection signal is output. And determining whether or not the two tire detection signals are tire detection signals caused by stepping on two tires attached to the same axle of the vehicle, based on the detection time information, And specifying the number of two pairs of tire detection signals determined to be tire detection signals by stepping on two tires attached to the same axle as the number of axles of the vehicle.

  A program for causing a computer of the axle number detection device to function, wherein the program outputs a tire detection signal indicating that the treadle installed in the lane width direction has detected the stepping of a tire of a vehicle traveling on the vehicle. A detection time information acquisition unit for acquiring detection time information indicating time, and based on the detection time information, two tire detection signals are tire detection signals by treading two tires attached to the same axle of the vehicle An axle determination unit that determines whether or not the number of pairs of the two tire detection signals determined to be a tire detection signal by stepping on two tires attached to the same axle, the axle of the vehicle It functions as an axle number specifying unit, which is specified as a number.

  According to the axle number detection device, the axle number detection method, and the program according to the present invention, the number of axles of the vehicle can be detected even when the vehicle enters obliquely with respect to the tread.

It is a figure which shows the whole structure of the axle number detection apparatus which concerns on 1st Embodiment. It is a figure which shows the function structure of the axle number detection apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the tread concerning 1st Embodiment. It is the 1st figure explaining the function of the axle number detection device concerning a 1st embodiment. It is a 2nd figure explaining the function of the axle number detection apparatus which concerns on 1st Embodiment. It is a figure which shows the processing flow of the axle number detection apparatus which concerns on 1st Embodiment. It is a figure which shows the function structure of the axle number detection apparatus which concerns on 2nd Embodiment. It is a 1st figure explaining the function of the axle number detection apparatus which concerns on 2nd Embodiment. It is a 2nd figure explaining the function of the axle number detection apparatus which concerns on 2nd Embodiment. It is a figure which shows the function structure of the axle number detection apparatus which concerns on 3rd Embodiment. It is a 1st figure explaining the function of the axle number detection apparatus which concerns on 3rd Embodiment. It is a 2nd figure explaining the function of the axle number detection apparatus which concerns on 3rd Embodiment. It is a 3rd figure explaining the function of the axle number detection apparatus which concerns on 3rd Embodiment. It is a 4th figure explaining the function of the axle number detection apparatus which concerns on 3rd Embodiment. It is a figure which shows the processing flow of the axle number detection apparatus which concerns on 3rd Embodiment. It is a 1st figure explaining the function of the axle number detection apparatus which concerns on 4th Embodiment. It is a 2nd figure explaining the function of the axle number detection apparatus which concerns on 4th Embodiment.

<First Embodiment>
Hereinafter, an axle number detection device according to a first embodiment of the present invention will be described with reference to FIGS.

(Overall configuration of axle number detection device)
FIG. 1 is a diagram illustrating an overall configuration of an axle number detection device according to the first embodiment.
The axle number detection device 1 according to the present embodiment is installed in a toll gate of an expressway having a lane L. The axle number detection device 1 is a device for detecting the number of axles of the vehicle A passing through the lane L.

As shown in FIG. 1, the axle number detection device 1 includes a vehicle detector 10, a tread board 20, and a control device 30.
The vehicle detector 10 is provided with a pair of light projecting and receiving light on both sides of the lane L. For each vehicle A, the vehicle detector 10 blocks the light projected by a light receiving sensor (not shown) arranged in the height direction (Z direction in FIG. 1) by the vehicle A entering the lane L. A vehicle detection signal that can detect the entry and passage of the vehicle is output to the control device 30.

The tread board 20 extends in the lane width direction (Y direction in FIG. 1) on the road surface of the lane L at the same position as the position where the vehicle detector 10 is installed in the lane direction (X direction in FIG. 1) ( It is installed over the lane width direction; its longitudinal direction is along the lane width direction.
The tread 20 has a plurality of tread pressure detection sensors inside, and outputs a tire detection signal corresponding to the tread pressure (press) by the tire of the vehicle A that has entered the lane L through the tread pressure detection sensor to the control device 30.

As shown in FIG. 1, the control device 30 is installed on the road side of the lane L and in the vicinity of the vehicle detector 10. The control device 30 is connected to the vehicle detector 10 and the tread board 20 by wire.
The control device 30 specifies the number of axles of the vehicle A passing through the lane L based on the vehicle detection signal received from the vehicle detector 10 and the tire detection signal received from the tread board 20.

(Functional configuration of axle number detection device)
FIG. 2 is a diagram illustrating a functional configuration of the axle number detection device according to the first embodiment.
FIG. 3 is a diagram illustrating a configuration of the tread according to the first embodiment.
As shown in FIG. 2, the axle number detection device 1 includes a vehicle detector 10, a tread board 20, and a control device 30.

As shown in FIGS. 2 and 3, the tread plate 20 has four contacts 200a, 200b, 200c, and 200d as tread pressure detection sensors. In the present embodiment, the contacts 200a to 200d are arranged side by side in the order of the contacts 200a, 200b, 200c, and 200d from the front side in the lane direction (the -X direction in FIG. 3) to the back side (the + X side in FIG. 3). Yes.
Each of the contacts 200a to 200d of the tread board 20 is provided with one electrode (not shown) on the road surface upper side (+ Z side in FIG. 1) and the road surface lower side (−Z side in FIG. 1). When each of the contact points 200a to 200d is stepped on by a tire of the vehicle A passing on the lane L, the road surface upper side electrode and the road surface lower side electrode provided at each of the contact points 200a to 200d come into contact with each other. Each contact 200a-200d detects the presence or absence of stepping by detecting the presence or absence of electricity supply by contact of two electrodes. When the tread board 20 detects that the contacts 200a to 200d are stepped in a prescribed order, that is, in order from the front side in the lane direction to the back side, the tread is determined by the tire of the vehicle A passing over the tread board 20. The tire detection signal is output to the control device 30 by determining that the vehicle is stepping.

As shown in FIG. 2, the control device 30 of the axle number detection device 1 includes a detection time information acquisition unit 300, an axle determination unit 301, and an axle number identification unit 302.
The detection time information acquisition unit 300 is a tread board during a period during which the vehicle A passes between the vehicle detectors 10 arranged on both sides of the lane L, that is, while a vehicle detection signal is output from the vehicle detector 10. The detection time information of the tire detection signal output from 20 is acquired. In the present embodiment, the detection time information of the tire detection signal is information indicating how many seconds after the detection time information acquisition unit 300 starts outputting the vehicle detection signal, the tire detection signal is output.
As the detection time information, an elapsed time from a prescribed timing such as a timing at which the axle number detection device 1 is activated may be used. In addition, the local time (regional standard time) of the point where the toll gate is installed may be used as the detection time information.

Here, a case where the vehicle A, which is a normal automobile having two axles, has passed the vehicle detector 10 will be described with reference to FIGS.
FIG. 4 is a first diagram illustrating functions of the axle number detection device according to the first embodiment.
FIG. 5 is a second diagram illustrating the function of the axle number detection device according to the first embodiment.
As shown in FIG. 4, the vehicle A has tires TR1 and TR2 on the first axle arranged at the foremost side (+ X side in FIG. 4) of the vehicle body. Tires TR3 and TR4 are provided on the second axle arranged on the -X side in FIG.
As shown in FIG. 4, for example, when the vehicle A enters obliquely with respect to the tread board 20 (when entering along the traveling direction shown in FIG. 4), the tires of the vehicle A are TR1, TR2, TR3, Passes on the tread board 20 in the order of TR4. The tread plate 20 outputs a tire detection signal to the control device 30 every time it detects the stepping by the tires TR1 to TR4 of the vehicle A.
The detection time information acquisition unit 300 of the control device 30 acquires the detection time information of the tire detection signal of the vehicle A output from the tread plate 20 during the period in which the vehicle detection signal of the vehicle A is output from the vehicle detector 10. . Then, as shown in FIG. 5, the detection time information acquisition unit 300 generates a detection pattern D by arranging the acquired tire detection signals in the order of detection times indicated by the detection time information, and outputs the detection pattern D to the axle determination unit 301.

As shown in FIG. 5, the vertical axis (first axis) of the detection pattern D represents the detection time indicated by the detection time information of the tire detection signal. The detection pattern D includes a period from the time when the vehicle detector 10 starts outputting the vehicle detection signal of the vehicle A (t0 in FIG. 5) to the time when the output of the vehicle detection signal is stopped (tn in FIG. 5). The tire detection signals of the vehicle A output from the tread board 20 are recorded side by side for each detection time.
4 and 5, the detection pattern D of the vehicle A includes a detection time t1 of the tire detection signal p1 related to the tire TR1, a detection time t2 of the tire detection signal p2 related to the tire TR2, and a tire TR3. Are recorded, a detection time t3 of the tire detection signal p3 related to, and a detection time t4 of the tire detection signal p4 related to the tire TR4.

Based on the detection time information of the tire detection signals p1 to p4 recorded in the detection pattern D of the vehicle A, the axle determination unit 301 is a tire detection signal of a tire attached to the same axle. Determine whether or not.
Specifically, the axle determination unit 301 selects two tire detection signals in order of detection time from the plurality of tire detection signals p1 to p4 recorded in the detection pattern D. Then, the axle determination unit 301 determines whether or not the time difference between the detection times of the two selected tire detection signals is within a preset allowable time. In the present embodiment, the allowable time is an installation angle of the tread plate 20 with respect to the lane L, a range of travel angles that the vehicle A can take with respect to the lane L, a vehicle speed assumed when the vehicle A travels in the lane L, and the like. It is set based on.
When the time difference between the detection times of the two selected tire detection signals is within the allowable time, the axle determination unit 301 indicates that the two tire detection signals are “a tire by stepping on two tires attached to the same axle”. It is a detection signal ”. On the other hand, when the time difference between the detection times of the two selected tire detection signals exceeds the allowable time, the axle determination unit 301 indicates that the two tire detection signals are “tires caused by stepping of two tires attached to different axles”. It is a detection signal ”.
In the case of a double tire in which two tires are attached to one end side and the other end side of the axle, “two tires attached to the same axle” means one end side or the other end side of the axle. Two tires attached to are counted as "one tire".

In the example of FIG. 5, the axle determination unit 301 first selects the tire detection signal p1 and the tire detection signal p2. Then, it is determined whether or not the time difference Δt1-2 between the detection time t1 of the tire detection signal p1 and the detection time t2 of the tire detection signal p2 is within an allowable time. When the axle determination unit 301 determines that Δt1-2 is within the allowable time, the tire detection signal p1 and the tire detection signal p2 are “a tire detection signal by stepping on two tires attached to the same axle. Is determined.
Next, the axle determination unit 301 selects the tire detection signal p2 and the tire detection signal p3. When the axle determination unit 301 determines that the time difference Δt2-3 between the detection time t2 of the tire detection signal p2 and the detection time t3 of the tire detection signal p3 exceeds the allowable time, the tire detection signal p2 and the tire detection signal p3 Is determined to be “a tire detection signal by stepping on two tires attached to different axles”.
Further, the axle determination unit 301 selects the tire detection signal p3 and the tire detection signal p4. When the axle determination unit 301 determines that the time difference Δt3-4 between the detection time t3 of the tire detection signal p3 and the detection time t4 of the tire detection signal p4 is within the allowable time, the tire detection signal p3 and the tire detection signal p4 Is determined to be “a tire detection signal by stepping on two tires attached to the same axle”.
The axle determination unit 301 thus determines whether or not the tire detection signal is a tire detection signal by stepping on two tires attached to the same axle as the tire detection signal whose detection time is around, for all tire detection signals. The determination result is output to the axle number specifying unit 302.

Based on the determination result acquired from the axle determination unit 301, the axle number specifying unit 302 is a pair of tire detection signals determined to be “a tire detection signal by stepping on two tires attached to the same axle”. Find a number. Then, the axle number specifying unit 302 specifies the number of pairs of tire detection signals as the number of axles of the vehicle A.
In the example of FIG. 5, the determination result acquired from the axle determination unit 301 includes the tire detection signals p1 and p2 that are determined to be “a tire detection signal by stepping on two tires attached to the same axle”. A pair and a pair of tire detection signals p3 and p4 are included. Therefore, the axle number specifying unit 302 determines that the number of tire detection signal pairs of the vehicle A is “2” based on the determination result. Then, the axle number specifying unit 302 specifies that the number of axles of the vehicle A is “2”.

(Processing flow of axle number detection device)
FIG. 6 is a diagram illustrating a processing flow of the axle number detection device according to the first embodiment.
As shown in FIG. 6, the detection time information acquisition unit 300 of the control device 30 outputs the tire detection signal of the vehicle A output from the tread board 20 during the period in which the vehicle detection signal of the vehicle A is output from the vehicle detector 10. Detection time information is acquired (step S100).

  Next, the detection time information acquisition unit 300 arranges the acquired tire detection signals in order of detection time, and generates a detection pattern D of the vehicle A (step S101). The detection time information acquisition unit 300 outputs the generated detection pattern D of the vehicle A to the axle determination unit 301.

  Next, the axle determination unit 301 selects two tire detection signals in order of detection time among the plurality of tire detection signals recorded in the detection pattern D (step S102). In the present embodiment, the axle determination unit 301 selects two tire detection signals in order from the oldest detection time.

Next, the axle determination unit 301 determines whether or not the time difference between the detection times of the two selected tire detection signals is within a preset allowable time (step S103).
When the axle determination unit 301 determines that the time difference between the detection times of the two selected tire detection signals is within a preset allowable time (step S103: YES), the two tire detection signals are “the same axle”. Is a tire detection signal by stepping on two tires attached to the vehicle "(step S104).
On the other hand, when the axle determination unit 301 determines that the time difference between the detection times of the two selected tire detection signals exceeds the preset allowable time (step S103: NO), the two tire detection signals are “different axles”. It is a tire detection signal by stepping on two tires attached to the vehicle "(step S105).

  Next, the axle determination unit 301 determines whether determination has been performed for all tire detection signals recorded in the detection pattern D (step S106). If axle determination unit 301 determines that there is an undetermined tire detection signal (step S106: NO), it returns to step S102 and repeats the same processing. On the other hand, when determining that there is no undetermined tire detection signal (step S106: YES), the axle determination unit 301 outputs the determination result to the axle number specifying unit 302 and proceeds to the next step.

  Next, based on the determination result acquired from the axle determination unit 301, the axle number identification unit 302 determines that the tire detection signal is “a tire detection signal by stepping on two tires attached to the same axle”. Find the number of pairs. Then, the axle number specifying unit 302 specifies the number of pairs of tire detection signals as the number of axles of the vehicle A (step S107).

(Function and effect)
As described above, the axle number detection device 1 according to the present embodiment includes the tread plate 20 that outputs a tire detection signal in response to the depression of the tire of the traveling vehicle A, and the detection time that indicates the time when the tire detection signal is output. Whether or not the two tire detection signals are tire detection signals by stepping on two tires attached to the same axle of vehicle A based on detection time information acquisition unit 300 that acquires information and detection time information The number of axles of the vehicle A is identified as the number of axles of the vehicle A, and the number of pairs of two tire detection signals determined to be a tire detection signal by stepping on two tires attached to the same axle And an axle number specifying unit 302.
By doing in this way, the axle determination part 301 is a tire detection signal by stepping of two tires with which two tire detection signals were attached to the same axle shaft among the tire detection signals output from the tread board 20. Is determined based on detection time information of each tire detection signal. This is a case where two tires attached to the same axle (for example, the tire TR1 and the tire TR2 in FIG. 4) step on the tread 20 at different timings, for example, the vehicle A enters the tread 20 obliquely. Even so, the axle determination unit 301 determines that the two tire detection signals having different detection time information output from the tread plate 20 are “tire detection signals by stepping on two tires attached to the same axle”. be able to. Therefore, the axle number detection device 1 can detect the number of axles with high accuracy while suppressing erroneous determination of the number of axles.

<Second Embodiment>
Next, an axle number detection device according to a second embodiment of the present invention will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment, and detailed description is abbreviate | omitted.

(Functional configuration of axle number detection device)
FIG. 7 is a diagram illustrating a functional configuration of the axle number detection device according to the second embodiment.
FIG. 8 is a first diagram illustrating the function of the axle number detection device according to the second embodiment.
FIG. 9 is a second diagram illustrating the function of the axle number detection device according to the second embodiment.
This embodiment is different from the first embodiment in that the control device 30 of the axle number detection device 1 further includes a vehicle speed estimation unit 303.

The detection time information acquisition unit 300 of the control device 30 according to the present embodiment acquires the detection time information of the tire detection signal output from the tread board 20. In the present embodiment, the detection time information of the tire detection signal includes detection times (four detection times) at which the contact points 200a to 200b of the tread plate 20 detect the stepping. And the detection time information acquisition part 300 arranges each acquired tire detection signal g1-g4 in order of detection time, as shown in FIG. 8, and produces | generates the detection pattern D. FIG.
Further, the detection time information acquisition unit 300 outputs the detection pattern D generated in this way to the axle determination unit 301 and the vehicle speed estimation unit 303.

The vehicle speed estimation unit 303 estimates the vehicle speed of the vehicle A based on the detection time information of the tire detection signal recorded in the detection pattern D of the vehicle A.
In the example of FIG. 8, the vehicle speed estimation unit 303 includes the detection times of the respective contacts 200a to 200d included in the detection time information of the tire detection signals of the tire detection signals g1 to g4 and the contact points 200a to 200d of the tread plate 20. Based on the distance, the vehicle speed when the tire of the vehicle A passes over the tread 20 is estimated. For example, in the detection time information of the tire detection signal g1, the vehicle speed estimation unit 303 detects the detection time (earliest detection time) when the contact 200a detects the stepping and the detection time (latest detection time) when the contact 200d detects the stepping. ) To find the time difference. And the vehicle speed estimation part 303 estimates the vehicle speed of the vehicle A based on the distance between the contact 200a and the contact 200d, and the time difference of the detection time of the contact 200a and the contact 200d. Similarly, the vehicle speed estimation unit 303 estimates the vehicle speed of the vehicle A at the timing when the tire detection signals g2 to g4 are detected based on the detection time information of the tire detection signals g2 to g4.
The vehicle speed estimation unit 303 outputs the estimated vehicle speed to the axle determination unit 301.

The axle determination unit 301 is based on the detection time information of the tire detection signals g1 to g4 recorded in the detection pattern D of the vehicle A, and the tire detection signals of the tires where the tire detection signals g1 to g4 are attached to the same axle. It is determined whether or not.
The axle determination unit 301 selects two tire detection signals in order of detection time from the plurality of tire detection signals g1 to g4 recorded in the detection pattern D. Then, it is determined whether or not the time difference between the detection times of the two selected tire detection signals is within an allowable time.
In the present embodiment, the axle determination unit 301 sets a value obtained by multiplying a predetermined reference time T by a coefficient α as an allowable time. The coefficient α is a variable value that changes according to the vehicle speed of the vehicle A estimated by the vehicle speed estimation unit 303. The axle determination unit 301 sets the value of the coefficient α so that the coefficient α becomes smaller as the vehicle speed of the vehicle A becomes faster and the coefficient α becomes larger as the vehicle speed of the vehicle A becomes slower. The axle determination unit 301 may refer to a table in which the value of the coefficient α is determined in advance for each vehicle speed of the vehicle A.
The axle determination unit 301 determines whether the time differences Δt1-2, Δt2-3, and Δt3-4 of the detection times t1 to t4 of the extracted tire detection signals are within the allowable time obtained as described above. And it is determined whether each tire detection signal g1-g4 is a tire detection signal by stepping on two tires attached to the same axle. Specifically, when the time difference between the two tire detection signals is within the allowable time, the axle determination unit 301 indicates that the two tire detection signals are tire detection signals obtained by stepping on two tires attached to the same axle. Judge that there is. On the other hand, when the time difference between the two tire detection signals exceeds the allowable time, the axle determination unit 301 determines that the two tire detection signals are tire detection signals obtained by stepping on two tires attached to different axles.
Note that the vehicle speed used when setting the coefficient α is, for example, an average value of the vehicle speed estimated for each tire detection signal. Different vehicle speeds may be used for each tire detection signal. In this case, for example, when determining whether or not the time difference between the tire detection signal g1 and the tire detection signal g2 in FIG. 8 is within the allowable time, the axle determination unit 301 is estimated based on the tire detection signal g1. The coefficient α is set according to the vehicle speed. When determining whether or not the time difference between the tire detection signal g2 and the tire detection signal g3 is within the allowable time, the axle determination unit 301 determines the coefficient α according to the vehicle speed estimated based on the tire detection signal g2. Set.

The axle determination unit 301 also detects each tire detection signal (vehicle) based on the detection time information of each tire detection signal g1 to g4 recorded in the detection pattern D of the vehicle A and the vehicle speed estimated by the vehicle speed estimation unit 303. You may obtain | require the estimated distance in the lane direction (X direction of FIG. 4) of each tire of A). In this case, as shown in FIG. 9, the axle determination unit 301 generates a detection pattern D ′ in which the tire detection signals g1 to g4 are arranged in the order of the estimated distance.
The vertical axis (first axis) of the detection pattern D ′ represents the estimated distance of each tire obtained by the axle determination unit 301 based on the detection time information of each tire detection signal. As the estimated distance, for example, an estimated distance from the starting point is used with the starting point (estimated distance d0 = 0) when the vehicle detector 10 starts outputting the vehicle detection signal of the vehicle A. Specifically, the estimated distance d1 of the tire detection signal g1 is obtained by integrating the elapsed time from the starting point d0 until the tire detection signal g1 is detected and the vehicle speed of the vehicle A. Further, the estimated distance d1 of the tire detection signal g2 is obtained by integrating the elapsed time from the detection of the tire detection signal g1 to the detection of the tire detection signal g2 and the vehicle speed of the vehicle A. Similarly, the subsequent tire detection signals are obtained by integrating the elapsed time between the tire detection signals and the vehicle speed of the vehicle A.
Note that the vehicle speed used for obtaining the estimated distance is, for example, an average value of the vehicle speed estimated for each tire detection signal. Different vehicle speeds may be used for each tire detection signal. In this case, for example, when the estimated distance d1 of the tire detection signal g1 in FIG. 9 is obtained, the axle determination unit 301 uses the vehicle speed estimated based on the tire detection signal g1. When determining the estimated distance d2 of the tire detection signal g2, the axle determination unit 301 uses the vehicle speed estimated based on the tire detection signal g2.
The axle determination unit 301 uses the same tire detection signals g1 to g4 based on the detection time information of the tire detection signals g1 to g4 recorded in the detection pattern D ′ of the vehicle A and the estimated distances d1 to d4. It is determined whether or not the tire detection signal is a tire attached to the tire.
The axle determination unit 301 selects two tire detection signals in order of detection time from the plurality of tire detection signals g1 to g4 recorded in the detection pattern D ′. Then, it is determined whether or not the difference between the estimated distances of the two selected tire detection signals is within an allowable range.
In the present embodiment, the axle determination unit 301 sets a predetermined distance (for example, within 1 m) as an allowable range. The axle determination unit 301 determines whether or not the differences Δd1-2, Δd2-3, and Δd3-4 of the estimated distances d1 to d4 of the extracted tire detection signals are within an allowable range, and the tire detection signals It is determined whether g1 to g4 are tire detection signals by stepping on two tires attached to the same axle. Specifically, when the difference between the estimated distances of the two tire detection signals is within an allowable range, the axle determination unit 301 determines that the two tire detection signals are tires caused by stepping on two tires attached to the same axle. Judged as a detection signal. On the other hand, when the difference between the estimated distances of the two tire detection signals exceeds the allowable range, the axle determination unit 301 determines that the two tire detection signals are tire detection signals by stepping on two tires attached to different axles. to decide.

(Function and effect)
For example, when the vehicle speed of the vehicle A traveling on the lane L is low, the tire TR2 (FIG. 4) attached to the same axle as the tire TR1 after the tire TR1 (FIG. 4) of the vehicle A steps on the tread plate 20. There is a possibility that the period until the tread plate 20 is stepped on (the time difference Δt1-2 of the detection time in FIG. 8) becomes longer. At this time, when the allowable time is set to a fixed value as in the first embodiment, the axle determination unit 301 determines that the time difference Δt1-2 between the detection times of the tire TR1 and the tire TR2 exceeds the allowable time. The tire TR1 and the tire TR2 may be erroneously determined as “tires attached to different axles”.
However, according to the axle number detection device 1 described above, the vehicle speed estimation unit 303 determines the vehicle speed of the vehicle A when the tire of the vehicle A passes over the tread plate 20 based on the tire detection signal output from the tread plate 20. Ask. Further, the axle determination unit 301 determines whether each tire detection signal g1 to g4 is a tire detection signal by stepping on two tires attached to the same axle according to the vehicle speed of the vehicle A. Change the allowable time. As a result, as in the above example, when the vehicle speed of the vehicle A is slow and the time difference Δt1-2 between the detection times of the tires TR1 and TR2 becomes long, the axle determination unit 301 sets the allowable time of the vehicle A. In order to set a longer time in accordance with the vehicle speed, the axle determination unit 301 correctly determines that the tire detection signals g1 and g2 of the tires TR1 and TR2 are “a tire detection signal by stepping on a tire attached to the same axle”. be able to. Thereby, the axle number detection apparatus 1 of this embodiment can detect the number of axles with higher accuracy.
Further, even when the axle determination unit 301 obtains the estimated distance of each tire detection signal and generates the detection pattern D ′, the same effect can be obtained.

<Third Embodiment>
Next, an axle number detection device according to a third embodiment of the present invention will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the same component as 1st and 2nd embodiment, and detailed description is abbreviate | omitted.

(Functional configuration of axle number detection device)
FIG. 10 is a diagram illustrating a functional configuration of an axle number detection device according to the third embodiment.
As shown in FIG. 10, the tread plate 20 of the axle number detection device 1 according to the present embodiment includes position detection contacts 201 a, 201 b, 201 c, and 201 d instead of the contacts 200 a, 200 b, 200 c, and 200 d. . Each of the position detection contacts 201a to 201d according to the present embodiment, like the contacts 200a to 200d, detects the position from the front side in the lane direction (the −X direction in FIG. 3) to the back side (the + X side in FIG. 3). The contact points 201a, 201b, 201c, and 201d are arranged in this order.
The position detection contacts 201a to 201d of the tread plate 20 are each provided with one electrode (not shown) on the road surface upper side (+ Z side in FIG. 1) and the road surface lower side (−Z side in FIG. 1). . When the position detection contacts 201a to 201d are stepped on by the tire of the vehicle A passing over the lane L, the electrode on the road surface upper side contacts the electrode on the road surface lower side. The position detection contacts 201a to 201d detect the presence / absence of stepping and the stepping position in the lane width direction by measuring the electric resistance value while detecting the presence / absence of energization due to the contact of the two electrodes. When the tread board 20 detects that the position detection contacts 201a to 201d are stepped in a prescribed order, that is, in order from the front side in the lane direction toward the back side, the treads are vehicles that pass on the tread board 20. The tire detection signal that can detect the stepping position in the lane width direction is output to the control device 30 by determining that the stepping is performed by the tire A.

  As shown in FIG. 10, the control device 30 of the axle number detection device 1 according to the present embodiment includes a detection time information acquisition unit 300, an axle determination unit 301, and an axle number identification unit according to the first and second embodiments. In addition to 302 and the vehicle speed estimation unit 303, a detection position information acquisition unit 305, a coordinate information generation unit 306, a vector information generation unit 307, and an exception processing unit 308 are included.

  The detected position information acquisition unit 305 is a lane in which the tire of the vehicle A steps on the tread plate 20 based on the tire detection signal output from the tread plate 20 while the vehicle detection signal of the vehicle A is output from the vehicle detector 10. Detection position information indicating a spatial position (detection position) in the width direction is acquired.

FIG. 11 is a first diagram illustrating the function of the axle number detection device according to the third embodiment.
FIG. 12 is a second diagram illustrating the function of the axle number detection device according to the third embodiment.
FIG. 13 is a third diagram illustrating the function of the axle number detection device according to the third embodiment.
FIG. 14 is a fourth diagram illustrating the function of the axle number detection device according to the third embodiment.
The coordinate information generation unit 306 generates coordinate information in which the detection time information acquired by the detection time information acquisition unit 300 from each tire detection signal and the detection position information acquired by the detection position information acquisition unit 305 are associated with each other.
Then, as shown in FIG. 11, the coordinate information generation unit 306 generates a spatiotemporal map M (two-dimensional map) in which a plurality of generated coordinate information is arranged in order of detection time and detection position, and a vector information generation unit 307. Output to.
As shown in FIG. 11, in the spatio-temporal map M, the vertical axis (first axis) represents the detection time of the tire detection signal, and the horizontal axis (second axis) represents the detection position of the tire detection signal. The spatio-temporal map M shows a period from the time when the vehicle detector 10 starts outputting the vehicle detection signal of the vehicle A (t0 in FIG. 11) to the time when the output of the vehicle detection signal stops (tn in FIG. 11). The coordinate information related to the tire detection signal of the vehicle A output from the tread board 20 is recorded in order of detection time and detection position.

4 and 11, in the space-time map M of the vehicle A, as coordinate information (detection time, detection position) of each tire of the vehicle A, coordinate information c1 (t1) of the tire detection signal related to the tire TR1. , Y1), coordinate information c2 (t2, y2) of the tire detection signal related to the tire TR2, coordinate information c3 (t3, y3) of the tire detection signal related to the tire TR3, and tire detection related to the tire TR4 The coordinate information c4 (t4, y4) of the signal is recorded.
For example, as shown in FIG. 4, when it is assumed that the vehicle A is traveling straight in a traveling direction that is an oblique direction with respect to the tread plate 20, tire detection signals of the tires TR1 and TR2 attached to the first axle. Is represented on the spatio-temporal map M as two points (coordinate information c1 and c2 in FIG. 11) inclined with respect to the detection time (vertical axis). Similarly, the tire detection signals of the tires TR3 and TR4 attached to the second axle are represented as two points (coordinate information c3 and c4 in FIG. 11) that are inclined with respect to the detection time on the spatiotemporal map M. .
Here, each axle of the vehicle A, for example, the first axle having the tires TR1 and TR2 in FIG. 4 and the second axle having the tires TR3 and TR4 are provided in parallel, that is, having the same inclination. Yes. For this reason, when the vehicle A passes over the tread 20 at a constant speed, the line connecting the coordinate information c1 and c2 related to the tire detection signals of the tires TR1 and TR2 and the tire detection signals of the tires TR3 and TR4 are related. The line connecting the coordinate information c3 and c4 has substantially the same inclination as the first axle and the second axle of the actual vehicle A. Note that the vehicle speed may change while the vehicle A passes the tread plate 20. In this case, the line connecting the coordinate information c1 and c2 and the line connecting the coordinate information c3 and c4 do not coincide with each other. For this reason, in the present embodiment, if the difference between the slope of the line connecting the coordinate information c1 and c2 and the slope of the line connecting the coordinate information c3 and c4 is within a predetermined range, “substantially the same slope is set. It is judged.
Further, when the vehicle A passes over the tread 20 with the approach angle with respect to the tread 20 kept constant, the tire TR1 disposed on one end side in the width direction of the vehicle body of the vehicle A (the −Y side in FIG. 4). And TR3 are represented at substantially the same detection position on the space-time map M. Similarly, the tires TR2 and TR4 arranged on the other end side in the width direction of the vehicle body of the vehicle A (+ Y side in FIG. 4) are represented on the spatio-temporal map M at substantially the same detection position. In addition, the approach angle with respect to the tread board 20 may change when the vehicle A performs a steering wheel operation while passing through the tread board 20. In this case, the detection positions of the tires TR1 and TR3 and the detection positions of the tires TR2 and TR4 do not match. For this reason, in this embodiment, if the difference between the detection positions in the lane width direction (Y direction in FIG. 4) of each tire is within a predetermined range, it is determined that “the detection positions are substantially the same position”.
For this reason, as shown in FIG. 4, the spatio-temporal map M of the vehicle A that has entered the diagonal direction with respect to the tread plate 20 as shown in FIG. 4 is two pieces of coordinate information related to tires attached to the same axle. And a line connecting two pieces of coordinate information related to tires arranged on the same side in the width direction of the vehicle body of the vehicle A forms a substantially parallelogram.

The vector information generation unit 307 generates vector information configured by selecting and combining two pieces of coordinate information from the coordinate information on the spatio-temporal map M generated by the coordinate information generation unit 306.
First, the vector information generation unit 307 determines whether or not two or more pieces of coordinate information are included on the spatiotemporal map M. When the coordinate information included in the spatio-temporal map M is one, the vector information generation unit 307 determines that the coordinate information cannot constitute vector information. Then, the vector information generation unit 307 assumes that the spatio-temporal map M is not a pattern of the spatio-temporal map assumed from a vehicle traveling on the lane L, and the tire detection signal related to the coordinate information is abnormal due to erroneous detection or the like. Judge that there is. In this case, the vector information generation unit 307 outputs state information indicating “abnormal” to the exception processing unit 308.
On the other hand, when there are two or more pieces of coordinate information included in the spatiotemporal map M, the vector information generation unit 307 determines that the spatiotemporal map M includes the coordinate information of the tire of the vehicle A.

When there are two or more pieces of coordinate information included in the spatiotemporal map M, the vector information generation unit 307 classifies the coordinate information into a first group and a second group.
For example, the vector information generation unit 307 extracts the minimum value y_min and the maximum value y_max of the detection position from the coordinate information included in the spatiotemporal map M, and obtains an intermediate value y_mid that is an intermediate value therebetween.
Then, the vector information generation unit 307 classifies the coordinate information having the detection position value equal to or lower than the intermediate value y_mid into the first group, and sets the coordinate information having the detection position value larger than the intermediate value y_max to the second group. Classify into: By doing in this way, the coordinate information relevant to the tire arrange | positioned at the one end side of the width direction of the vehicle body of the vehicle A is classified into a 1st group, and the coordinate information relevant to the tire arrange | positioned at the other end side is It becomes classified into the second group.
When the minimum value y_min and the maximum value y_max are the same value and the coordinate information included in the spatiotemporal map M is only two, the vector information generating unit 307 indicates that the spatiotemporal map M is “two-wheeled vehicle”. It is determined that the pattern of the space-time map is shown. In this case, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle” to the exception processing unit 308. The vector information generation unit 307 assumes the case where the traveling direction of the vehicle A (FIG. 4) changes while passing on the tread board 20 due to the operation of the driver of the vehicle A, etc., and the minimum value y_min and the maximum value y_max. If the difference is within a certain range, it is determined that the values are the same.

Next, the vector information generation unit 307 selects one piece of coordinate information with the earliest detection time from the first group and one piece of coordinate information with the earliest detection time from the second group. Then, the vector information generation unit 307 generates vector information S1 by combining the selected two pieces of coordinate information, and outputs the vector information S1 to the axle determination unit 301.
Further, the vector information generation unit 307 determines whether or not one or more pieces of coordinate information exist in each of the first group and the second group, except for the two coordinate information constituting the vector information S1. .
When the vector information generation unit 307 determines that one or more coordinate information exists in the first group and one or more coordinate information exists in the second group, the first group and the second group From each of the groups, the coordinate information with the earliest detection time is selected one by one, excluding the two coordinate information constituting the vector information S1. Then, the vector information generation unit 307 generates vector information S2 by combining the selected two pieces of coordinate information, and outputs the vector information S2 to the axle determination unit 301. In addition, the vector information generation unit 307 performs the same processing when one or more coordinate information exists in each of the first group and the second group, except for the coordinate information constituting the generated vector information. Vector information is repeatedly generated and output to the axle determination unit 301.
On the other hand, the vector information generation unit 307 does not have coordinate information in either one of the first group and the second group, except for the two coordinate information constituting the vector information S1, and the first group and the second group. When one coordinate information exists in either one of the two groups, the coordinate information included in the spatiotemporal map M is three, and coordinate information other than the coordinate information constituting the vector information S1 (third It is determined that there is no coordinate information paired with the coordinate information). In this case, the vector information generation unit 307 determines that the spatiotemporal map M indicates a spatiotemporal map pattern of “two-wheeled vehicle with side vehicle”. In this case, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle with side vehicle” to the exception processing unit 308.
Further, when no coordinate information exists in any of the first group and the second group except for the two coordinate information constituting the vector information S1, the vector information generation unit 307 determines that the spatiotemporal map M is a lane. The tire detection signal related to the coordinate information constituting the vector information S1 is determined to be abnormal due to erroneous detection, assuming that the pattern of the spatiotemporal map assumed from the vehicle traveling on L is not. In this case, the vector information generation unit 307 outputs state information indicating “abnormal” to the exception processing unit 308.
Except for “two-wheeled vehicles” and “two-wheeled vehicles with side vehicles”, it is assumed that a vehicle traveling in the lane L has one tire disposed on one end side and the other end side of each axle. For this reason, the vector information generation unit 307 determines which one of the coordinate information of the first group and the coordinate information of the second group, unless it is determined that the vehicle is a “two-wheeled vehicle” and “a two-wheeled vehicle with a side vehicle”. When coordinate information exists only in one (when the number of coordinate information included in the spatiotemporal map M is four or more and the number of coordinate information does not match between the first group and the second group), The vector information generation unit 307 determines that the space-time map M includes coordinate information that cannot constitute vector information. When the coordinate information that cannot constitute the vector information is included in the space-time map M in this way, the vector information generation unit 307 indicates that the space-time map M is a space-time map assumed from a vehicle traveling on the lane L. If it is not a pattern, it is determined that the tire detection signal related to the coordinate information is abnormal due to erroneous detection or the like. In this case, the vector information generation unit 307 outputs state information indicating “abnormal” to the exception processing unit 308.

In the example of FIG. 11, the vector information generation unit 307 extracts the minimum value y_min (y1, y3) and the maximum value y_max (y2, y4) of the detection position from the coordinate information c1 to c4, and obtains the intermediate value y_mid.
Then, the vector information generation unit 307 classifies the coordinate information c1 and c3 having the detection position value equal to or lower than the intermediate value y_mid into the first group, and the coordinate information c2 having the detection position value larger than the intermediate value y_mid and Classify c4 into the second group.
Next, the vector information generation unit 307 selects coordinate information one by one in order of detection time from each of the first group and the second group. Specifically, the vector information generation unit 307 selects the coordinate information c1 (t1, y1) having the earliest detection time value from the first group, and has the earliest detection time value from the second group. The coordinate information c2 (t2, y2) is selected. The vector information generation unit 307 generates vector information S1 by combining the coordinate information c1 (t1, y1) and the coordinate information c2 (t2, y2) thus selected, and outputs the vector information S1 to the axle determination unit 301.
Further, the vector information generation unit 307 selects the coordinate information c3 (t3, y3) having the earliest detection time value from the first group, except for the coordinate information c1 and c2 constituting the vector information S1, and The coordinate information c4 (t4, y4) having the earliest detection time value is selected from the second group. The vector information generation unit 307 generates vector information S2 by combining the coordinate information c3 (t3, y3) and the coordinate information c4 (t4, y4) selected in this way, and outputs the vector information S2 to the axle determination unit 301.

  Also, as in the example of FIG. 12, even when there are six pieces of coordinate information c1 to c6, the vector information generation unit 307 uses the first and second groups of coordinate information c1 to c6 as in the example of FIG. Vector information S1 (coordinate information c1, c2) and S2 (coordinate information c3, c4) that are selected and combined one by one in the order of detection time from the first group and the second group. , S3 (coordinate information c5, c6) is generated and output to the axle determination unit 301.

  Further, as in the example of FIG. 13, the space-time map M includes only two pieces of coordinate information c1 (t1, y1) and coordinate information c2 (t2, y2), and the coordinate information c1 and c2 When the minimum value y_min and the maximum value y_max are the same value, that is, when the coordinate information c1 and c2 have the same detection position (y1 = y2), the vector information generation unit 307 indicates that the space-time map M is “two-wheeled vehicle”. It is determined that the pattern of the space-time map is shown. Then, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle” to the exception processing unit 308.

  Further, as in the example of FIG. 14, when the space-time map M includes three pieces of coordinate information c1 (t1, y1), coordinate information c2 (t2, y2), and coordinate information c3 (t3, y3), The vector information generation unit 307 generates vector information S1 obtained by selecting and combining the coordinate information c1 and c2 having the earliest detection time from each of the first group and the second group. Then, the vector information generation unit 307 determines whether or not one or more coordinate information exists in each of the first group and the second group, except for the coordinate information c1 and c2 constituting the vector information S1. To do. In the example of FIG. 14, the coordinate information c3 exists in the first group except for the coordinate information c1 and c2 constituting the vector information S1, but the coordinate information does not exist in the second group. The coordinate information included in M is three, and it is determined that there is no coordinate information paired with coordinate information c3 other than the coordinate information c1 and c2 constituting the vector information S1. In this case, the vector information generation unit 307 determines that the spatiotemporal map M indicates a spatiotemporal map pattern of “two-wheeled vehicle with side vehicle”. For this reason, the vector information generation unit 307 determines that the vehicle A is a “two-wheeled vehicle with a side vehicle”, and outputs state information indicating “two-wheeled vehicle with a side vehicle” to the exception processing unit 308.

Based on the vector information acquired from the vector information generation unit 307, the axle determination unit 301 is configured to step on two tires attached to the same axle by using two tire detection information related to coordinate information constituting the vector information. It is determined whether or not the tire detection signal is.
First, the axle determination unit 301 determines whether or not the inclination of the vector information S1 configured with the coordinate information with the earliest detection time is within a predetermined allowable angle. In the present embodiment, the allowable angle includes an installation angle of the tread plate 20 with respect to the lane L, a range of travel angles that the vehicle A can take with respect to the lane L, a vehicle speed assumed when the vehicle A travels in the lane L, and the like. A value obtained by multiplying the reference angle θ set based on the above by the coefficient β is set. The coefficient β is a variable value that changes according to the vehicle speed of the vehicle A estimated by the vehicle speed estimation unit 303. The axle determination unit 301 sets the value of the coefficient β so that the coefficient β becomes smaller as the vehicle speed of the vehicle A becomes faster and the coefficient β becomes larger as the vehicle speed of the vehicle A becomes slower. The axle determination unit 301 may refer to a table in which the value of the coefficient β is determined in advance for each vehicle speed of the vehicle A.
When the axle determination unit 301 determines that the inclination of the vector information S1 is within a predetermined allowable angle, the tire detection signal related to the two coordinate information constituting the vector information S1 is “the same axle ( It is a tire detection signal by stepping on two tires attached to the first axle).
On the other hand, when the axle determination unit 301 determines that the inclination of the vector information S1 is larger than the allowable angle, the spatiotemporal map M is not a pattern of a spatiotemporal map assumed from a vehicle traveling on the lane L. It is determined that the tire detection signal related to the coordinate information included in the spatiotemporal map M is abnormal due to erroneous detection or the like. In this case, the axle determination unit 301 outputs state information indicating “abnormal” to the exception processing unit 308.

In addition, the axle determination unit 301 determines that the inclination (direction in the spatio-temporal map M) of the vector information S2 configured by the coordinate information having the detection time next to the vector information S1 is the inclination (spatio-temporal map) of the vector information S1. It is determined whether or not it matches the direction in M).
As described above, since the axles of the vehicle A are provided with the same inclination, when the inclination of the vector information S2 is the same as the inclination of the vector information S1 related to the first axle, the axle In the determination unit 301, the tire detection signal related to the two coordinate information constituting the vector information S2 is “a tire detection signal by treading two tires attached to the same axle (second axle)”. judge.
On the other hand, if the axle determination unit 301 determines that the inclination of the vector information S2 is different from the inclination of the vector information S1, the spatiotemporal map M is not a pattern of the spatiotemporal map assumed from a vehicle traveling on the lane L. The tire detection signal related to the coordinate information included in the spatiotemporal map is determined to be abnormal due to erroneous detection or the like. In this case, the axle determination unit 301 outputs state information indicating “abnormal” to the exception processing unit 308.
The axle determination unit 301 assumes the inclination of the vector information S1 on the assumption that the traveling direction of the vehicle A (FIG. 4), the vehicle speed, and the like change while passing on the tread plate 20 due to the operation of the driver of the vehicle A and the like. If the difference between the slopes of the vector information S2 is within a certain range, it is determined that the slopes of the two vector information (directions in the spatiotemporal map M) match.

The axle determination unit 301 makes the same determination for all vector information acquired from the vector information generation unit 307. When the inclination of the vector information Sn to be determined is the same as the inclination of the vector information Sn ₋₁ immediately before the vector information Sn (the detection time is earlier), the axle determination unit 301 It is determined that the tire detection signal related to the two coordinate information constituting the information Sn is “a tire detection signal by stepping on two tires attached to the same axle”. When the determination of all the vector information is completed, the axle determination unit 301 outputs the determination result to the axle number specifying unit 302.
On the other hand, when the axle determination unit 301 determines that the inclination of the vector information Sn is different from the inclination of the vector information Sn- ₁ , the spatiotemporal map M is a spatiotemporal map pattern assumed from a vehicle traveling on the lane L. It is determined that the tire detection signal related to the coordinate information included in the spatiotemporal map M is abnormal due to erroneous detection or the like. In this case, the axle determination unit 301 outputs state information indicating “abnormal” to the exception processing unit 308.

When the exception processing unit 308 acquires state information from the vector information generation unit 307 or the axle determination unit 301, the exception processing unit 308 performs processing according to the state information.
When the exception processing unit 308 acquires the state information indicating “two-wheeled vehicle” from the vector information generation unit 307, the exception processing unit 308 outputs a tire detection signal related to each coordinate information included in the spatio-temporal map M as “stepping on tires of different axles”. It is determined that the tire detection signal is. The exception processing unit 308 outputs the determination result to the axle number specifying unit 302 together with the state information indicating “two-wheeled vehicle”.
Further, when the exception processing unit 308 acquires the state information indicating “two-wheeled vehicle with a side vehicle” from the vector information generation unit 307, the exception processing unit 308 generates “different” tire detection signals related to each coordinate information included in the spatiotemporal map M. It is a tire detection signal by stepping on the tire on the axle ”. The exception processing unit 308 outputs the determination result to the axle number specifying unit 302 together with the state information indicating “two-wheeled vehicle with a side vehicle”.
Further, when the exception processing unit 308 acquires state information indicating “abnormal” from the vector information generation unit 307 or the axle determination unit 301, the exception processing unit 308 outputs the state information indicating “abnormal” to the axle number specifying unit 302.

When the axle number specifying unit 302 obtains the determination result from the axle determining unit 301, the tire detection that is determined as “a tire detection signal by stepping on two tires attached to the same axle” included in the determination result. Find the number of signal pairs. Then, the axle number specifying unit 302 specifies the number of pairs of tire detection signals as the number of axles of the vehicle A.
In the example of FIG. 11, the determination result determined by the axle determination unit 301 includes the coordinate information c1 of the tire detection signal determined to be “a tire detection signal by stepping on two tires attached to the same axle” and A pair of c2 and a pair of coordinate information c3 and c4 of the tire detection signal are included. Therefore, the axle number specifying unit 302 determines that the number of tire detection signal pairs of the vehicle A is “2” based on the determination result. Then, the axle number specifying unit 302 specifies that the number of axles of the vehicle A is “2”.

In addition, when the axle number specifying unit 302 obtains a determination result from the exception processing unit 308 together with the state information indicating “two-wheeled vehicle” or “two-wheeled vehicle with a side vehicle”, the number-of-axes identifying unit 302 The number of tire detection signals determined to be “a tire detection signal by stepping on a tire of a different axle” is counted as the tire detection signal related to each coordinate information included. Then, the axle number specifying unit 302 specifies the counted number of tire detection signals as the number of axles of the vehicle A.
Furthermore, when notified from the exception processing unit 308 that the axle number could not be determined, the axle number specifying unit 302 ends the process without specifying the number of axles of the vehicle A.

(Processing flow of axle number detection device)
FIG. 15 is a diagram illustrating a processing flow of the axle number detection device according to the third embodiment.
As illustrated in FIG. 15, the coordinate information generation unit 306 of the control device 30 includes the detection time information acquired by the detection time information acquisition unit 300 from each tire detection signal, and the detection position information acquired by the detection position information acquisition unit 305. Is generated (step S200). Then, the coordinate information generation unit 306 generates a spatio-temporal map M (FIGS. 11 to 14) in which the generated plurality of coordinate information is arranged in the order of detection time and detection position, and outputs the spatiotemporal map M to the vector information generation unit 307.

Next, the vector information generation unit 307 determines whether or not two or more pieces of coordinate information are included in the spatiotemporal map M acquired from the coordinate information generation unit 306 (step S201).
When the coordinate information included in the spatio-temporal map M is one or less (step S201: NO), the vector information generation unit 307 outputs state information indicating “abnormal” to the exception processing unit 308, and proceeds to step S220. .
On the other hand, when the coordinate information included in the spatiotemporal map M is two or more (step S201: YES), the vector information generation unit 307 determines that the spatiotemporal map M includes the coordinate information of the tire of the vehicle A. The process proceeds to the next step S202.

Next, the vector information generation unit 307 extracts the minimum value y_min and the maximum value y_max of the detection position from the coordinate information included in the spatiotemporal map M, and whether or not the minimum value y_min and the maximum value y_max are the same value. Is determined (step S202). The vector information generation unit 307 determines that the minimum value y_min and the maximum value y_max of the coordinate information are the same value (step S202: YES), and the coordinate information included in the spatiotemporal map M is two. If so, vehicle A is determined to be a “two-wheeled vehicle” (step S203). In this case, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle” to the exception processing unit 308. In addition, the exception processing unit 308 that has acquired the state information indicating “two-wheeled vehicle” indicates that the tire detection signal related to each piece of coordinate information included in the spatiotemporal map M is “a tire detection signal by stepping on a tire of a different axle”. Is determined. The exception processing unit 308 outputs the determination result to the axle number specifying unit 302 together with the state information indicating “two-wheeled vehicle”, and proceeds to the next step S219.
On the other hand, when the vector information generation unit 307 determines that the minimum value y_min and the maximum value y_max of the coordinate information are not the same value (step S202: NO), the vector information generation unit 307 obtains the intermediate value y_mid from the minimum value y_min and the maximum value y_max. . Then, the vector information generation unit 307 classifies the coordinate information into two groups based on the intermediate value y_mid (step S204). Specifically, the vector information generation unit 307 classifies the coordinate information having the detection position value equal to or lower than the intermediate value y_mid into the first group, and sets the coordinate information having the detection position value larger than the intermediate value y_max to the first value. Classify into two groups.
In the present embodiment, a description is given of an aspect in which the vector information generation unit 307 obtains an intermediate value y_mid from the minimum value y_min and the maximum value y_max of the coordinate information, and classifies the coordinate information into two groups based on the intermediate value y_mid. However, it is not limited to this. In another embodiment, for example, regression lines may be obtained from all coordinate information included in the spatiotemporal map M, and the coordinate information may be classified into two groups based on the regression line.

Next, the vector information generation unit 307 selects one piece of coordinate information with the earliest detection time from the first group and one piece of coordinate information with the earliest detection time from the second group. Then, the vector information generation unit 307 generates vector information S1 by combining the selected two pieces of coordinate information (step S205), and outputs the vector information S1 to the axle determination unit 301.
Further, the vector information generation unit 307 determines whether or not one or more pieces of coordinate information exist in each of the first group and the second group, except for the two coordinate information constituting the vector information S1. (Step S206).
The vector information generation unit 307 has one or more pieces of coordinate information in the first group and one or more pieces of coordinate information in the second group, except for two pieces of coordinate information constituting the vector information S1. When it is determined that it exists (step S206: YES), the process proceeds to the next step S209.
On the other hand, the vector information generation unit 307 does not have one or more pieces of coordinate information in either one of the first group and the second group, except for two coordinate information constituting the vector information S1 (step S206: NO), when one coordinate information exists in either one of the first group and the second group (step S207: YES), it is determined that the vehicle A is a “two-wheeled vehicle with a side vehicle” (step S207). S208). Then, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle with side vehicle” to the exception processing unit 308. In addition, the exception processing unit 308 that has acquired the state information indicating “the two-wheeled vehicle with the side vehicle” generates a tire detection signal related to each coordinate information included in the spatio-temporal map M as “tire detection by stepping on tires of different axles”. It is a signal. The exception processing unit 308 outputs the determination result to the axle number specifying unit 302 together with the state information indicating “two-wheeled vehicle with side vehicle”, and proceeds to the next step S219.
If there is no other coordinate information in either the first group or the second group (step S206: NO and step S207: NO), the vector information generation unit 307 notifies the exception processing unit 308 that “abnormal Is output, and the process proceeds to the next step S220.

Next, the axle determination unit 301 determines whether the inclination of the vector information S1 acquired from the vector information generation unit 307 is within an allowable angle (step S209).
When the axle determination unit 301 determines that the inclination of the vector information S1 is larger than the allowable angle (step S209: NO), the axle determination unit 301 outputs status information indicating “abnormal” to the exception processing unit 308, and proceeds to the next step S220. .
On the other hand, when the axle determination unit 301 determines that the inclination of the vector information S1 is within an allowable angle (step S209: YES), the tire detection signal related to the two coordinate information constituting the vector information S1 is “ This is a tire detection signal by stepping on two tires attached to the same axle ”(step S210).

  Next, the vector information generation unit 307 selects one coordinate information with the earliest detection time from the first group, except for the two coordinate information constituting the vector information S1, and detects the detection time from the second group. Select the coordinate information with the earliest. Then, the vector information generation unit 307 generates vector information S2 by combining the two selected coordinate information (step S211), and outputs the vector information S2 to the axle determination unit 301.

Next, the axle determination unit 301 determines whether or not the inclination of the vector information S2 acquired from the vector information generation unit 307 is the same as the inclination of the vector information S1 (step S212).
When the axle determination unit 301 determines that the inclination of the vector information S2 is the same as the inclination of the vector information S1 (step S212: YES), the tire detection signal related to the two coordinate information constituting the vector information S2 is , “It is a tire detection signal by stepping on two tires attached to the same axle” is determined (step S213).
On the other hand, if the axle determination unit 301 determines that the inclination of the vector information S2 is not the same as the inclination of the vector information S1 (step S212: NO), it outputs state information indicating “abnormal” to the exception processing unit 308, Proceed to the next Step S220.

Next, the vector information generation unit 307 determines whether or not one or more pieces of coordinate information exist in each of the first group and the second group, except for the coordinate information constituting the already generated vector information. (Step S214).
The vector information generation unit 307 does not include one or more pieces of coordinate information in any one of the first group and the second group except for the coordinate information that constitutes the already generated vector information (step S214: NO). When one piece of coordinate information exists in one of the first group and the second group (step S215: YES), status information indicating “abnormal” is output to the exception processing unit 308.
Further, when there is no coordinate information in any of the first group and the second group except for the coordinate information constituting the already generated vector information (step S214: NO and step S215: NO), the vector The information generation unit 307 ends the process and proceeds to the next step S219.
On the other hand, the vector information generation unit 307 has one or more pieces of coordinate information in the first group, and one or more coordinates in the second group, except for coordinate information constituting the already generated vector information. When it is determined that the information exists (step S214: YES), one coordinate information with the earliest detection time is selected from the coordinate information of the first group, and the detection time is the highest among the coordinate information of the second group. Select one fast coordinate information. Then, the vector information generation unit 307 generates vector information Sn by combining the selected two pieces of coordinate information (Step S216), and outputs the vector information Sn to the axle determination unit 301.

Next, the axle determination unit 301 determines whether or not the inclination of the vector information Sn acquired from the vector information generation unit 307 is the same as the inclination of the vector information Sn ₋₁ (step S217).
When the axle determination unit 301 determines that the inclination of the vector information Sn is the same as the inclination of the vector information Sn- ₁ (step S217: YES), the tire detection related to the two coordinate information constituting the vector information Sn. The signal is determined to be “a tire detection signal by stepping on two tires attached to the same axle” (step S218). Then, the process returns to step S214.
On the other hand, if the axle determination unit 301 determines that the inclination of the vector information Sn is not the same as the inclination of the vector information Sn ₋₁ (step S217: NO), the state information indicating “abnormal” is output to the exception processing unit 308. Then, the process proceeds to the next step S220.

When the number-of-axes identifying unit 302 acquires the determination results of all vector information from the axle determining unit 301, it is “a tire detection signal due to treading of two tires attached to the same axle” included in the determination result. The number of determined tire detection signal pairs is obtained. Then, the axle number specifying unit 302 specifies the number of pairs of tire detection signals as the number of axles of the vehicle A (step S219).
In addition, when the axle number specifying unit 302 acquires the determination result from the exception processing unit 308 together with the state information indicating “two-wheeled vehicle” or “two-wheeled vehicle with side vehicle” (step S203, step S208), the determination result The number of tire detection signals determined to be “a tire detection signal by stepping on a tire of a different axle” is counted as the tire detection signal related to each coordinate information included in the included spatiotemporal map M. Then, the axle number specifying unit 302 specifies the counted number of tire detection signals as the number of axles of the vehicle A (step S219).

  Also, the axle number identification unit 302 is notified by the exception processing unit 308 that the axle could not be determined (step S201: NO, step S207: NO, step S209: NO, step S212: NO, step S215). : YES), the process is terminated without specifying the number of axles of the vehicle A (step S220).

(Function and effect)
As described above, the axle number detection device 1 according to the present embodiment includes the detection position information acquisition unit 305 that acquires the detection position information indicating the position where the tire treading is detected in the lane width direction based on the tire detection signal. Based on the detection time information and the detection position information, for each of the tire detection signals, the position in the spatiotemporal map M with the first axis as the detection time and the second axis as the detection position in the lane width direction is indicated. A coordinate information generation unit 306 that generates coordinate information, and a vector information generation unit 307 that generates vector information obtained by selecting and combining two of the plurality of coordinate information in the order of detection time are further provided.
The vector information generation unit 307 generates vector information configured by selecting and combining two pieces of coordinate information among the coordinate information included in the spatiotemporal map M.
The axle determination unit 301 determines that the inclination of the vector information S1 generated by the vector information generation unit 307 (the direction in the spatiotemporal map M) is within an allowable angle and the inclination of the vector information S2 (or vector information Sn). When the inclination of the vector information S1 (or vector information Sn ₋₁ ) is the same, the two coordinate information constituting the vector information S2 is “a tire detection signal by treading two tires attached to the same axle”. It is determined.
As a result, the axle determination unit 301 refers to the vector information having the same inclination even when the vehicle A enters the tread board 20 at an angle, so that the “identical” It is possible to accurately determine a “tire detection signal by stepping on two tires attached to an axle”.

Further, the vector information generation unit 307 according to the present embodiment classifies the plurality of coordinate information into the first group and the second group based on the detected position information, and the coordinate information selected from the first group. And the coordinate information selected from the second group are combined to generate vector information.
By doing in this way, vector information generation part 307 is the one end side in the lane width direction of vehicle A (Y direction of Drawing 4) based on detection position information on a plurality of coordinate information contained in spatiotemporal map M. Can be classified into the coordinate information of the tire detection signal due to the treading of the tire and the coordinate information of the tire detection signal due to the treading of the tire on the other end side. For this reason, the vector information generation unit 307 can generate vector information by quickly and accurately selecting two pieces of coordinate information related to tires attached to the same axle.

In addition, the vector information generation unit 307 according to the present embodiment selects coordinate information from the first group and the second group one by one in the order of detection times indicated by the detection time information.
In this way, the vector information generation unit 307 can generate vector information by quickly selecting two pieces of coordinate information. Thereby, the processing speed of the axle number detection device 1 can be improved.

Further, the vector information generation unit 307 according to the present embodiment is included in the detected position information of the coordinate information and the spatio-temporal map M when there is coordinate information that cannot constitute the vector information among the plurality of coordinate information. Based on the number of coordinate information, it is determined whether or not the tire detection signal related to the coordinate information is a false detection.
In this way, the vector information generation unit 307, for example, has only one coordinate information in the spatio-temporal map M, and when the vector information cannot be configured by the coordinate information, the spatio-temporal map M Assuming that this is not the pattern of the spatio-temporal map assumed from the vehicle traveling on the lane L, it can be determined that the tire detection signal related to the coordinate information is a false detection.
Further, for example, the vector information generation unit 307 is a case where coordinate information that cannot constitute vector information is included in the spatiotemporal map M, and there are two pieces of coordinate information included in the spatiotemporal map M. When the two pieces of coordinate information have the same detected position information, it can be determined that the spatio-temporal map M indicates the pattern of the spatio-temporal map of “two-wheeled vehicle”.
Further, for example, the vector information generation unit 307 is a case where coordinate information that cannot constitute vector information is included in the spatiotemporal map M, and there are three coordinate information included in the spatiotemporal map M. In this case, it can be determined that the spatiotemporal map M shows a pattern of the spatiotemporal map of the “two-wheeled vehicle with a side vehicle”.

In the present embodiment, the vector information generation unit 307 selects one coordinate information from the first group in the order of detection time and selects one coordinate information from the second group in the order of detection time. Although the aspect which produces | generates vector information combining two coordinate information was demonstrated, it is not restricted to this.
In another embodiment, the vector information generation unit 307 obtains all combinations of two pieces of coordinate information from all coordinate information included in the spatiotemporal map M, and generates a plurality of vector information for each combination of coordinate information. You may make it do. In this case, the axle determination unit 301 determines that the vector information extending in the lane width direction (horizontal axis in FIG. 11) of the plurality of vector information matches the inclination of the vector information extending in the other lane width direction. select. The axle determination unit 301 determines that the tire detection signal related to the two pieces of coordinate information constituting the vector information selected in this way is “a tire detection signal by stepping on two tires attached to the same axle”. To do.
Also according to such an aspect, the axle determination unit 301 has two tire detection signals related to the two coordinate information combined as the vector information based on vector information whose directions in the spatio-temporal map match. It is a tire detection signal by stepping on two tires attached to the same axle ”.

  Further, the vector information generation unit 307 estimates the tire width from the detected position information of the coordinate information included in the spatiotemporal map M, and generates vector information by combining two pieces of coordinate information having the same tire width. Good. In this way, the vector information generation unit 307 has a single tire having one tire on each of one end and the other end of the same axle, and two tires on one end and the other end of the same axle. A double tire can be determined based on the tire width, and vector information can be generated more accurately. As a result, the accuracy of detection of the number of axles by the axle number detection device 1 can be improved.

<Fourth Embodiment>
Next, an axle number detection device according to a fourth embodiment of the present invention will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the same component as 1st, 2nd and 3rd embodiment, and detailed description is abbreviate | omitted.

(Function of axle number detection device)
FIG. 16 is a first diagram illustrating the function of the axle number detection device according to the fourth embodiment.
FIG. 17 is a second diagram illustrating the function of the axle number detection device according to the fourth embodiment.
In the axle number detection device 1 according to the present embodiment, when the tread plate 20 detects that the position detection contacts 201a to 201d are stepped in a prescribed order, that is, in order from the lane direction front side to the back side. The stepping is determined to be stepping by the tire of the vehicle A passing on the tread board 20, and a tire detection signal capable of detecting the stepping position in the lane width direction is output to the control device 30.
The coordinate information generation unit 306 of the control device 30 determines the tire detection signal (each tire of the vehicle A) based on the detection time information of the tire detection signal acquired from the tread board 20 and the vehicle speed estimated by the vehicle speed estimation unit 303. The estimated distance in the lane direction (X direction in FIG. 4) is obtained. Then, the coordinate information generation unit 306 determines that the tire detection signal is “related to stepping on one tire” and generates “coordinate information of a stable tire”.
Further, when the tread plate 20 detects that each of the position detection contacts 201a to 201d has not been stepped correctly, the tread plate 20 determines that the stepping is not the stepping by the tire of the vehicle A, and sets the stepping position in the lane width direction. A detectable abnormal stepping detection signal is output to the control device 30. The coordinate information generation unit 306 receives each abnormal stepping signal in the same manner as when the tire detection signal is acquired based on the detection time information of the abnormal stepping detection signal acquired from the tread board 20 and the vehicle speed estimated by the vehicle speed estimation unit 303. The estimated distance in the lane direction (X direction in FIG. 4) of the attached detection signal is obtained. Then, when an abnormal stepping detection signal is acquired from the tread board 20, the coordinate information generation unit 306 determines that there is a possibility that the tire has been stepped and generates “coordinate information of unstable tire”.
The “stable tire coordinate information” and “unstable tire coordinate information” include detection position information of the tire detection signal and an estimated distance.
When the position detection contacts 201a to 201d are not correctly stepped, for example, when it is detected that only part of the position detection contacts 201a to 201d is stepped, the position detection contacts 201a to 201d are This is the case when it is detected that the steps are stepped in a different order from the prescribed order.
For example, when a vehicle A having a light axle load on each axle, such as a “two-wheeled vehicle”, passes on the tread plate 20, the tread (pressing force) by the tire of the vehicle A against the position detection contacts 201a to 201d of the tread plate 20 ) Is insufficient, some of the position detection contacts 201a to 201d may not be able to detect the stepping by the tire of the vehicle A.
Further, while the vehicle A, which is a “two-wheeled vehicle”, is passing on the tread board 20, the driver of the vehicle A may step on the tread board 20. In this case, only the position detection contact arranged at a position where the driver's foot is in contact with the tread board 20 detects the stepping, and the position where the driver's foot is not in contact with the tread board 20. The contact for detection does not detect treading.
As described above, when it is detected that each of the position detection contacts 201a to 201d is not correctly stepped and an abnormal stepping detection signal is output, the axle number detection device 1 steps on the stepping plate 20 with the tire of the vehicle A. There is a possibility that it is impossible to determine whether or not the vehicle tire is insufficient or whether something other than the tire of the vehicle A (such as the driver's foot) is in contact with the tread board 20, and the correct number of axles cannot be detected. For this reason, when the coordinate information generation unit 306 of the control device 30 according to the present embodiment acquires an abnormal stepping detection signal from the tread board 20, the coordinate information generation unit 306 determines that the tire stepping may be detected, Tire coordinate information "is generated. The coordinate information generation unit 306 arranges the “stable tire coordinate information” and the “unstable tire coordinate information” generated as described above in the order of the estimated distance and the detected position in order of the two-dimensional space map M ′ (two-dimensional map). ) And output to the vector information generation unit 307.

As shown in FIGS. 16 and 17, the vertical axis (first axis) of the two-dimensional space map M ′ is obtained by the coordinate information generation unit 306 based on the detection time information of the tire detection signal and the abnormal stepping detection signal. It represents the estimated distance of each tire. Further, the horizontal axis (second axis) of the two-dimensional space map M ′ represents the detection positions of the tire detection signal and the abnormal stepping detection signal.
Specifically, for example, when the stepping with the front wheels of the vehicle A, which is a “two-wheeled vehicle”, is sufficient, but the stepping with the rear wheels is insufficient, the coordinate information generation unit 306 displays a two-dimensional space map as shown in FIG. M ′ is generated. That is, when the coordinate information generation unit 306 acquires a tire detection signal having detection position information indicating the detection position y1 from the tread board 20 when the front wheel of the vehicle A passes over the tread board 20, the coordinate information generation unit 306 is based on the tire detection signal. “Stable tire coordinate information c1” is generated. On the other hand, when the coordinate information generation unit 306 acquires an abnormal stepping detection signal having detection position information indicating the detection position y2 from the stepboard 20 when the rear wheel of the vehicle A passes over the stepboard 20, the abnormal stepping is performed. Based on the detection signal, “coordinate information c2 of unstable tire” is generated.
For example, when the driver of the vehicle A that is a two-wheeled vehicle puts his or her foot on the tread board 20, the coordinate information generation unit 306 generates a two-dimensional space map M ′ as shown in FIG. That is, when the coordinate information generation unit 306 acquires a tire detection signal having detection position information indicating the detection position y1 from the tread board 20 when the front wheel of the vehicle A passes over the tread board 20, the coordinate information generation unit 306 is based on the tire detection signal. “Stable tire coordinate information c1” is generated. Further, when the coordinate information generation unit 306 acquires an abnormal stepping detection signal having detection position information indicating the detection position y2 from the step board 20 at the time when the driver of the vehicle A puts his foot on the step board 20, the abnormality information Based on the stepping detection signal, “coordinate information c2 of unstable tire” is generated. Furthermore, when the coordinate information generation unit 306 acquires a tire detection signal having detection position information indicating the detection position y3 from the tread board 20 when the rear wheel of the vehicle A passes over the tread board 20, the coordinate information generation unit 306 is based on the tire detection signal. To generate “stable tire coordinate information c3”.

The vector information generation unit 307 generates vector information based on the two-dimensional space map M ′ generated by the coordinate information generation unit 306, as in the third embodiment described above.
When the two-dimensional space map M ′ includes “unstable tire coordinate information”, the vector information generation unit 307 according to this embodiment includes “stable tire coordinate information” and the “unstable tire coordinate information”. "The coordinate information of the unstable tire" based on whether or not the two-dimensional space map M 'configured by "" corresponds to the pattern of the two-dimensional space map M' assumed from the vehicle traveling in the lane L. Is based on whether the tire of the vehicle A is stepped on, or whether it is a false detection caused by stepping on a tire other than the tire of the vehicle A.

  For example, when the vector information generation unit 307 acquires the two-dimensional space map M ′ illustrated in FIG. 16, the coordinate information included in the two-dimensional space map M ′ is “stable tire coordinate information c1” and “unstable tire”. The minimum value y_min and the maximum value y_max of the detection position of these two pieces of coordinate information are the same value (y1 = y2), so that the vehicle A is a two-dimensional vehicle of a two-wheeled vehicle. It is determined that the pattern corresponds to the pattern of the space map M ′. For this reason, the vector information generation unit 307 determines that the “coordinate information c2 of the unstable tire” is due to the stepping on the tire of the vehicle A.

For example, when the vector information generation unit 307 acquires the two-dimensional space map M ′ illustrated in FIG. 17, the coordinate information included in the two-dimensional space map M ′ is “stable tire coordinate information c1”, “ There is no coordinate information that is paired with "stable tire coordinate information c3", which is the coordinate information c3 "of the stable tire" and "coordinate information c3 of the stable tire". In this case, the vector information generation unit 307 determines that the “coordinate information c2 of the unstable tire” is that of the “two-wheeled vehicle with a side vehicle” or the driver of the “two-wheeled vehicle” puts his / her foot on the tread plate 20. Judge whether it is a false detection at the time of connection.
When the vehicle A is a “two-wheeled vehicle with a side vehicle”, the detection positions y1 and y3 of the coordinate information c1 and c2 indicating the front and rear wheels of the vehicle A and the detection position y2 of the coordinate information c2 indicating the tire of the side vehicle Therefore, the angle formed by the line connecting the coordinate information c1 and c2 and the line connecting the coordinate information c2 and c3 is “acute angle”.
On the other hand, when the vehicle A is a “two-wheeled vehicle” and the driver of the vehicle A puts his or her foot on the tread board 20, as shown in FIG. 17, the coordinates of the stable tire indicating the front and rear wheels of the vehicle A are displayed. The distance between the detection positions y1 and y3 of the information c1 and c2 ”and the“ coordinate information c2 of the unstable tire ”indicating the position where the driver of the vehicle A is on the foot is more than the case of the“ two-wheeled vehicle with a side vehicle ”. Therefore, the angle formed by the line connecting the coordinate information c1 and c2 and the line connecting the coordinate information c2 and c3 is an “obtuse angle”.
For this reason, the vector information generation unit 307 includes a line connecting the first coordinate information c1 and the second coordinate information c2 in order of detection time among the three coordinate information c1 to c3, and the second coordinate information c2. And the angle formed by connecting the third coordinate information c3 is obtained as the “false detection determination angle”.
When the “false detection determination angle” is “acute angle”, the vector information generation unit 307 considers the vehicle A to be “a two-wheeled vehicle with a side vehicle”, and the “unstable tire coordinate information c2” Judgment is related to the tire detection signal of the tire. In this case, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle with side vehicle” to the exception processing unit 308. On the other hand, when the “false detection determination angle” is “obtuse angle” as shown in FIG. 17, the vector information generation unit 307 considers the vehicle A as “two-wheeled vehicle” and “coordinate information c2 of unstable tire”. Is determined to be a false detection. In this case, the vector information generation unit 307 outputs state information indicating “two-wheeled vehicle” to the exception processing unit 308.

Further, the vector information generation unit 307, when there are four or more coordinate information included in the two-dimensional space map M ′, when the “coordinate information of unstable tire” can constitute any vector information, The “unstable tire coordinate information” is determined to be related to the tire detection signal of the tire of the vehicle A. In this case, the vector information generation unit 307 generates vector information including the “coordinate information of unstable tire” and outputs the vector information to the axle determination unit 301.
On the other hand, when the “coordinate information of the unstable tire” cannot constitute vector information, that is, there are four or more coordinate information included in the two-dimensional space map M ′, and the first group and the second group If the number of coordinate information does not match and there is no coordinate information paired with “coordinate information of unstable tire”, it is determined that the “coordinate information of unstable tire” is a false detection. In this case, the vector information generation unit 307 generates vector information from the coordinate information excluding the “unstable tire coordinate information” and outputs the vector information to the axle determination unit 301.

(Function and effect)
As described above, when the coordinate information generation unit 306 according to the present embodiment acquires a tire detection signal from the tread board 20, the coordinate information generation unit 306 determines that the tire detection signal is “related to stepping on one tire” and determines “stable Tire coordinate information "is generated. On the other hand, when the coordinate information generation unit 306 acquires an abnormal stepping detection signal from the tread board 20, the coordinate information generation unit 306 determines that the abnormal stepping detection signal may be caused by the stepping of one tire, Information ".
In addition, when the “unstable tire coordinate information” is included in the two-dimensional space map M ′, the vector information generation unit 307 calculates “stable tire coordinate information” and “unstable tire coordinate information”. Based on whether or not the configured two-dimensional space map M ′ corresponds to the pattern of the two-dimensional space map assumed from the vehicle traveling on the lane L, the “unstable tire coordinate information” is It is determined whether it is due to a tire treading or a false detection.
By doing in this way, for example, even when the stepping by the tire of the vehicle A with respect to the position detection contacts 201a to 201d of the tread board 20 is insufficient, the vector information generation unit 307 displays “coordinate information of unstable tire”. Can be correctly determined to be caused by the stepping on the tire of the vehicle A. Thereby, the precision of the detection of the number of axles by the axle number detection apparatus 1 can be improved.

  In the above-described embodiment, the coordinate information generation unit 306 generates a two-dimensional space map M ′ in which “stable tire coordinate information” and “unstable tire coordinate information” are arranged in order of estimated distance on the vertical axis. Although the aspect which performs is demonstrated, it is not restricted to this. In another embodiment, the coordinate information generation unit 306 is similar to the third embodiment in which “stable tire coordinate information” and “unstable tire coordinate information” are arranged in order of detection time on the vertical axis. A spatiotemporal map M may be generated. In this case, the coordinate information generation unit 306 sets the detection time information of each coordinate information to the detection time assumed when each vehicle travels at a predetermined speed based on the vehicle speed of the vehicle A estimated by the vehicle speed estimation unit 303. The spatiotemporal map M is generated by correction. In this way, the vector information generation unit 307 makes the “false detection determination angle” constant if the vehicle A is the same vehicle A even when the vehicle A travels slower or faster than a predetermined speed. Therefore, it is possible to accurately determine whether the “coordinate information of the unstable tire” is related to the tire detection signal of the “two-wheeled vehicle with a side vehicle” or is a false detection.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of 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 modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Axle number detection apparatus 10 Vehicle detector 20 Tread board 200a, 200b, 200c, 200d Contact 201a, 201b, 201c, 201d Contact for position detection 30 Control apparatus 300 Detection time information acquisition part 301 Axle judgment part 302 Axle number identification part 303 Vehicle speed Estimating unit 305 Detected position information acquiring unit 306 Coordinate information generating unit 307 Vector information generating unit 308 Exception processing unit A Vehicle L Lane D, D ′ Detection pattern M Space-time map (two-dimensional map)
M '2D space map (2D map)
TR1, TR2, TR3, TR4 tires

Claims (7)

A tread board that is installed in the lane width direction and outputs a tire detection signal in response to the treading of a tire of a traveling vehicle;
A detection time information acquisition unit for acquiring detection time information indicating a time when the tire detection signal is output;
An axle determination unit that determines whether the two tire detection signals are tire detection signals by stepping on two tires attached to the same axle of the vehicle, based on the detection time information;
An axle number specifying unit for specifying, as the number of axles of the vehicle, the number of pairs of two tire detection signals determined to be tire detection signals by stepping on two tires attached to the same axle;
Axle number detection device comprising: Based on the tire detection signal, a detection position information acquisition unit that acquires detection position information indicating a position at which the stepping of the tire in the lane width direction is detected;
Based on the detection time information and the detection position information, for each of the tire detection signals, the first axis is a value based on the detection time information, and the second axis is a spatial position in the lane width direction. A coordinate information generator for generating coordinate information indicating a position in the two-dimensional map;
A vector information generating unit that generates vector information configured by selecting and combining two of the plurality of coordinate information;
Further comprising
The axle determination unit is configured to detect the two tires related to the two pieces of coordinate information combined as the vector information based on the vector information having the same direction in the two-dimensional map among the plurality of vector information. Determining that the signal is a tire detection signal by stepping on two tires attached to the same axle of the vehicle;
The axle number detection device according to claim 1. The vector information generator is
Classifying the plurality of coordinate information into a first group and a second group based on the detected position information;
Generating the vector information by combining the coordinate information selected from the first group and the coordinate information selected from the second group;
The axle number detection device according to claim 2. The vector information generator is
From each of the first group and the second group, the coordinate information is selected one by one in the order of detection times indicated in the detection time information,
The axle number detection device according to claim 3. When there is coordinate information that cannot constitute the vector information among the plurality of coordinate information, the vector information generation unit includes the detected position information of the coordinate information and the coordinate information included in the two-dimensional map. Determining whether the tire detection signal related to the coordinate information is a false detection based on the number of
The axle number detection device according to any one of claims 2 to 4. Outputting a tire detection signal in response to stepping on a tire of a traveling vehicle;
Obtaining detection time information indicating the time at which the tire detection signal was output;
Based on the detection time information, determining whether the two tire detection signals are tire detection signals by stepping on two tires attached to the same axle of the vehicle;
Specifying the number of two pairs of tire detection signals determined to be tire detection signals by stepping on two tires attached to the same axle as the number of axles of the vehicle;
A method for detecting the number of axles. A computer for detecting the number of axles
A detection time information acquisition unit for acquiring detection time information indicating a time at which a tire detection signal indicating that a tread of a vehicle on which a tread board installed in the lane width direction has traveled is detected;
An axle determination unit that determines whether the two tire detection signals are tire detection signals by stepping on two tires attached to the same axle of the vehicle, based on the detection time information,
Axle number specifying unit that specifies the number of two tire detection signal pairs determined to be a tire detection signal by stepping on two tires attached to the same axle as the number of axles of the vehicle,
Program to function as.

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