JP2021135640A - Axle number detection device, toll collection system, axle number detection method, and program - Google Patents

Abstract

To provide an axle number detection device, a toll collection system, an axle number detection method, and a program that make it difficult to erroneously detect the number of axles of a tire that touches the ground.SOLUTION: An axle number detection device comprises: a temperature distribution acquisition unit that acquires temperature distribution information regarding a side surface of a traveling vehicle; a temperature range acquisition unit that acquires a predetermined temperature range; a high temperature region specifying unit that specifies a high temperature region which belongs to a predetermined temperature range of temperature distribution information; and an axle number specifying unit that specifies the number of axles based on the high temperature region.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to an axle number detection device, a toll collection system, an axle number detection method, and a program.

In the toll collection system on a toll road, a method of determining a toll based on the vehicle type of a vehicle is known as a method of determining a toll. Vehicle type is determined by using various vehicle information such as the number of axles, vehicle length, vehicle height, license plate information, and presence / absence of towing.
For example, Patent Document 1 discloses a method of determining the number of axles of a traveling vehicle as vehicle information.

International Publication No. 2019/0664682

In Patent Document 1, in order to detect the number of axles of a vehicle having a lift axle mechanism, the lowest point of each tire is calculated from a photographed image of the tire, and the lowest point of the rearmost tire of the vehicle is used as a reference. The lift-up of the intermediate tire is judged.
Therefore, depending on the tire condition, the surrounding environment, the shooting position, etc., the lowest point of the tire cannot be specified, and the number of axles of the tire that touches the ground may be erroneously detected.

The present disclosure has been made to solve the above problems, and provides an axle number detection device, a toll collection system, an axle number detection method, and a program that make it difficult to erroneously detect the number of axles of a tire that touches the ground. With the goal.

In the present disclosure, a temperature distribution acquisition unit that acquires temperature distribution information regarding the side surface of a traveling vehicle, a temperature range acquisition unit that acquires a predetermined temperature range, and a region of the temperature distribution information that belongs to the predetermined temperature range. This is an axle number detecting device including a high temperature region specifying unit for specifying a high temperature region, and an axle number specifying unit for specifying the number of axles based on the high temperature region.

The present disclosure includes a temperature distribution acquisition unit that acquires temperature distribution information regarding the side surface of a traveling vehicle, a tire region identification unit that specifies a tire region from a photographed image of the side surface, and the tire region and the temperature distribution information. Based on this, it is an axle number detecting device including an axle number specifying unit for specifying the number of axles.

The present disclosure specifies a step of acquiring temperature distribution information regarding the side surface of a traveling vehicle, a step of acquiring a predetermined temperature range, and a high temperature region which is a region belonging to the predetermined temperature range in the temperature distribution information. This is a method for detecting the number of axles, which includes a step of determining the number of axles and a step of specifying the number of axles based on the high temperature region.

In the present disclosure, the number of axles is specified based on a step of acquiring temperature distribution information regarding the side surface of a traveling vehicle, a step of specifying a tire region from a photographed image of the side surface, and the tire region and the temperature distribution information. It is a method of detecting the number of axles including the step to be performed.

In the present disclosure, a computer of an axle number detecting device is provided with a step of acquiring temperature distribution information regarding the side surface of a traveling vehicle, a step of acquiring a predetermined temperature range, and the temperature distribution information in the predetermined temperature range. It is a program for executing a step of specifying a high temperature region to which the region belongs and a step of specifying the number of axles based on the high temperature region.

In the present disclosure, a step of acquiring temperature distribution information about a side surface of a traveling vehicle by a computer of an axle number detecting device, a step of specifying a tire region from a photographed image of the side surface, and the tire region and the temperature distribution information Based on the above, it is a program to execute the step of specifying the number of axles.

According to the axle number detection device, the toll collection system, the axle number detection method, and the program of the present disclosure, it is difficult to erroneously detect the number of axles of a tire that touches the ground.

It is the schematic perspective view of the toll collection system which concerns on 1st Embodiment of this disclosure. It is a side view of the vehicle which concerns on 1st Embodiment of this disclosure. It is a figure which shows the temperature distribution information acquired by the temperature distribution detection apparatus which concerns on 1st Embodiment of this disclosure. It is a block diagram of the axle number detection device which concerns on 1st Embodiment of this disclosure. It is a figure which shows the high temperature region specified by the high temperature region identification part which concerns on 1st Embodiment of this disclosure. It is a flowchart of the axle number detection method which concerns on 1st Embodiment of this disclosure. It is a side view of the vehicle which has the lift axle mechanism which concerns on 1st Embodiment of this disclosure. It is an enlarged view of the VIII part of FIG. 7 when it is lifted up. It is a figure which shows the high temperature region specified by the high temperature region identification part which concerns on 1st Embodiment of this disclosure at the time of lift-up. It is an enlarged view of the VIII part of FIG. 7 when it is not lifted up. It is a figure which shows the high temperature region specified by the high temperature region identification part which concerns on 1st Embodiment of this disclosure when it is not lifted up. It is a schematic perspective view of the charge collection system which concerns on the 2nd Embodiment of this disclosure. It is a block diagram of the axle number detection device which concerns on 2nd Embodiment of this disclosure. It is a figure which shows the ground contact tire region determined by the shaft number specifying part which concerns on 2nd Embodiment of this disclosure. It is a flowchart of the axle number detection method which concerns on 2nd Embodiment of this disclosure. This is an example of the hardware configuration of the computer included in the axle number detection device according to each embodiment of the present disclosure.

Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding configurations are designated by the same reference numerals in all drawings, and common description will be omitted.

<First Embodiment>
The axle number detection device according to the first embodiment will be described with reference to the drawings.

(Overall configuration of toll collection system)
The toll collection system 1 of the present embodiment is provided at the entrance tollhouse (or the exit tollhouse depending on the toll type) of the expressway, which is a toll road, and is related to the vehicle AA on which the user of the expressway rides. It is a system for collecting the amount of money that has been paid.

Vehicle AA is traveling in the lane LN leading from the general road side to the expressway side via the entrance tollhouse. Island ISs are laid on both sides of the lane LN, and at least a part of various devices constituting the toll collection system 1 is installed.
For example, vehicle AA may be a towing vehicle that includes a towing trailer.

Hereinafter, the direction in which the lane LN extends (± X direction in FIG. 1) is described as “lane direction”, and the expressway side (+ X direction side in FIG. 1) in the lane direction of the lane LN is described as “downstream”. .. Further, the general road side (-X direction side in FIG. 1) in the lane direction of the lane LN is described as "upstream".
Further, the width direction of the lane LN is referred to as the lane width direction (± Y direction in FIG. 1), and the vehicle height direction of the vehicle AA is referred to as the vertical direction (± Z direction in FIG. 1).

In the present embodiment, the toll collection system 1 performs billing processing by the wireless communication system.
The toll collection system 1 is a device that performs wireless communication processing (hereinafter, simply referred to as "wireless communication") with the vehicle AA that is about to pass through the entrance tollhouse, and performs billing processing related to the vehicle type of the vehicle AA. Is.
For example, the toll collection system 1 may be a part of a system for constructing an electronic toll collection system (ETC: Electronic Toll Collection System (registered trademark), also referred to as “automatic toll collection system”).

As shown in FIG. 1, the toll collection system 1 includes a vehicle detector 2, a communication antenna 3, and a vehicle type determination device 4.
For example, the charge collection system 1 further includes a charge processing unit (not shown) that controls a series of charge processing, and the acquired information, the determined charge amount information, and the like are not shown and are installed in a remote place via a communication line. It may be output to the central payment processing device (upper device).

(Communication antenna configuration)
The communication antenna 3 is installed above the lane LN.
The communication antenna 3 performs wireless communication processing with the vehicle-mounted device α of the vehicle AA. Specifically, the communication antenna 3 is formed so as to be able to transmit and receive electromagnetic waves of a predetermined frequency (for example, about 5.8 GHz), and wirelessly communicates with the on-board unit α mounted on the vehicle AA that arrives via the electromagnetic waves. Communicate.
For example, the communication antenna 3 may be provided downstream of the approach detection position XA.

(Configuration of vehicle type discrimination device)
The vehicle type discrimination device 4 is installed on the island IS.
For example, the vehicle type determination device 4 may acquire the vehicle length, vehicle height, number of shafts, shaft weight, license plate information, and the like of the vehicle AA that has entered the lane LN detected by various sensors of the toll collection system 1.
The vehicle type determination device 4 identifies the vehicle type classification of the vehicle AA that has entered the lane LN based on various information (vehicle length, vehicle height, number of axles, license plate information, etc.) obtained through various sensors.
For example, the vehicle type classification is divided into five categories: "light vehicle / motorcycle", "ordinary vehicle", "medium-sized vehicle", "large vehicle", and "extra-large vehicle".
For example, the toll collection system 1 may charge a charge according to the vehicle type classification of the vehicle AA from the vehicle type classification specified by the vehicle type determination device 4.

(Vehicle detector configuration)
The vehicle detector 2 is configured to be able to detect the vehicle AA at the approach detection position XA in the lane direction (± X direction).
The vehicle detector 2 includes a temperature distribution detection device 22 and a processing unit 23.
For example, the vehicle detector 2 may further include a light emitting / receiving device 21.

(Configuration of temperature distribution detector)
The temperature distribution detection device 22 detects the temperature distribution information TDI regarding the side surface of the traveling vehicle AA.
The temperature distribution detection device 22 detects the temperature distribution information TDI including at least a region corresponding to the tire TR.
The temperature distribution detection device 22 outputs the detected temperature distribution information TDI to the processing unit 23.
For example, the temperature distribution detection device 22 may detect the temperature distribution information TDI from the roadside.
For example, the temperature distribution detection device 22 may be installed on the island IS.
Further, the temperature distribution detection device 22 may be installed from the island IS toward the lane LN so that the vehicle AA passing through the approach detection position XA is reflected in the field of view.

For example, the temperature distribution detection device 22 may be a thermal camera. At that time, the temperature distribution detection device 22 may be an area scan type thermal camera.
Further, the temperature distribution detection device 22 may be provided adjacent to the light emitting / receiving device 21 downstream in the lane direction.

For example, with respect to the vehicle AA traveling on the road surface SL of the lane LN, the temperature distribution detection device 22 may detect the temperature distribution with respect to at least the side surface of the vehicle AA including the tire TR as shown in FIG.
As a result, the temperature distribution detection device 22 may acquire the temperature distribution information TDI as shown in FIG.
In FIG. 3, in the temperature distribution information TDI, the low temperature region is shown in black and the high temperature region is shown in white.

(Structure of light receiving and receiving device)
The light emitting / receiving device 21 is arranged at the approach detection position XA.
The light emitting / receiving device 21 detects whether or not the projected light can be received, and outputs the light detection signal DS to the processing unit 23.
The light emitting / receiving device 21 may be a transmissive type or a reflective type.
For example, the light emitting / receiving device 21 may receive / receive light in the vertical plane parallel to the lane width direction (in the plane perpendicular to the ± X direction) at the approach detection position XA over the entire vehicle height direction of the vehicle AA. good.
For example, as shown in FIG. 1, when the light emitting / receiving device 21 is a transmissive type, the light emitting / receiving device 21 is a light projecting device 21A that projects light across a lane LN and a light receiving device 21B that receives the light. May have a pair with. At that time, the projector 21 receives the light projected by the floodlight 21A when the vehicle AA does not exist at the approach detection position XA, and emits the light projected by the floodlight 21A when the vehicle AA exists at the approach detection position XA. Does not receive light.
Therefore, when the light emitting / receiving device 21 is a transmissive type, the photodetector signal DS indicates that the light is not received when the vehicle AA is present at the approach detection position XA.
When the light emitting / receiving device 21 is a reflection type, the photodetector signal DS indicates that the light is received when the vehicle AA is present at the approach detection position XA.

(Structure of processing unit)
The processing unit 23 processes, communicates, and the like various data in the vehicle detector 2.
As shown in FIG. 4, the processing unit 23 includes a detection unit 24 and an axle number detection device 25.
For example, the processing unit 23 may be installed on the island IS.
Further, the processing unit 23 may be provided downstream of the light emitting / receiving device 21 and the temperature distribution detection device 22.

The detection unit 24 acquires the photodetector signal DS from the light emitting / receiving device 21.
The detection unit 24 detects whether or not the vehicle AA exists at the approach detection position XA based on the light detection signal DS of the light emitting / receiving device 21.
When the light emitting / receiving device 21 is a transmissive type, the detection unit 24 detects that the vehicle AA is present at the approach detection position XA when the light detection signal DS indicates that the light is not received.
When the light emitting / receiving device 21 is a reflective type, the detection unit 24 detects that the vehicle AA is present at the approach detection position XA when the light detection signal DS indicates that the light is received.

For example, when the detection unit 24 detects that the vehicle AA exists at the approach detection position XA, the detection unit 24 may notify the vehicle type determination device 4 that the vehicle AA has been detected.
Further, the detection unit 24 may continuously detect the presence of the vehicle AA from the time when the detection of the presence of the vehicle AA starts to the time when the detection of the presence of the vehicle AA ends as one vehicle.

(Configuration of axle number detection device)
The axle number detection device 25 processes and communicates various data for detecting the number of axles (number of axles).
The axle number detection device 25 functionally includes a temperature distribution acquisition unit 251, a temperature range acquisition unit 252, and a high temperature region identification unit 253.
For example, the axle number detecting device 25 may further functionally include the axle number specifying unit 254.
Further, the axle number detection device 25 may notify the vehicle type determination device 4 of the detected number of axles of the vehicle AA.

The temperature distribution acquisition unit 251 acquires the temperature distribution information TDI regarding the side surface of the traveling vehicle AA.
For example, the temperature distribution acquisition unit 251 may acquire the temperature distribution information TDI from the temperature distribution detection device 22.

The temperature range acquisition unit 252 acquires a predetermined temperature range TP.
For example, the temperature range acquisition unit 252 may acquire the road surface temperature TSL from the temperature distribution information TDI and acquire a predetermined temperature range TP based on the road surface temperature TSL.
At that time, the temperature range acquisition unit 252 may acquire the temperature at the position corresponding to the road surface SL in the temperature distribution information TDI as the road surface temperature TSL, as shown in FIG. Further, the position corresponding to the road surface SL may be a predetermined position in the temperature distribution information TDI.

The temperature range acquisition unit 252 may acquire a temperature range having a lower limit of the temperature obtained by adding a predetermined temperature difference to the road surface temperature TSL as a predetermined temperature range TP.
At that time, the predetermined temperature difference may be set in advance by measuring the temperature difference between the temperature indicated by the grounded tire TR of the vehicle AA during traveling and the road surface temperature as a sample.

For example, the temperature range acquisition unit 252 may acquire a predetermined temperature range TP stored in advance by the user, or may acquire a predetermined temperature range TP based on an automatic threshold value acquired from a statistical value of the temperature distribution information TDI or the like. May be obtained.

The high temperature region specifying unit 253 identifies the high temperature region RGH which is a region belonging to a predetermined temperature range TP in the temperature distribution information TDI.
The temperature of the grounded tire TR of the vehicle AA during traveling is higher than that at rest.
Therefore, in the temperature distribution information TDI including the temperature distribution of the vehicle AA during traveling, at least the region corresponding to the tire TR that is in contact with the ground as shown in FIG. 5 is specified as the high temperature region RGH.

For example, the high temperature region identification unit 253 may associate a plurality of high temperature region RGHs specified while the detection unit 24 detects the vehicle AA as one vehicle with the vehicle AA.
As a result, if the vehicle AA has four axle ASs and all the tires TR included in each axle AS are in contact with the ground (in contact with the road surface SL), at least the vehicle AA is as shown in FIG. The high temperature region RGH corresponding to the four tire TRs is identified.
In FIG. 5, in the temperature distribution information TDI, the region where the temperature is high is shown in white, so that the annular range shown in white is determined to be the ground contact tire region RGC.

The number of axles specifying unit 254 specifies the number of axles based on the high temperature region RGH.
For example, the number of axles specifying unit 254 may specify the number of axles including the tire TR that comes into contact with the ground.
Here, the number of axles of the tire TR that touches the ground is the number of axle ASs including the tire TR that touches the ground among the axle ASs of the vehicle AA.
At that time, the number of axles specifying unit 254 may notify the number of axles specified in the vehicle AA as the number of detected axles of the vehicle AA.

For example, the number of axles specifying unit 254 may count the number of RGH in the high temperature region itself and specify it as the number of axles.
For example, the number of axles specifying unit 254 may specify the number of axles from a region having a circular shape or an annular shape in the high temperature region RGH.

(motion)
The operation of the axle number detection device 25 of this embodiment will be described.
The operation of the axle number detection device 25 corresponds to the axle number detection method of the present embodiment.

First, as shown in FIG. 6, the temperature distribution acquisition unit 251 acquires the temperature distribution information TDI regarding the side surface of the traveling vehicle AA (ST01: temperature distribution acquisition step).
Following the implementation of ST01, the temperature range acquisition unit 252 acquires a predetermined temperature range TP (ST02: temperature range acquisition step).
Following the implementation of ST02, the high temperature region identification unit 253 identifies the high temperature region RGH which is a region belonging to the predetermined temperature range TP in the temperature distribution information TDI (ST03: high temperature region identification step).
Following the implementation of ST03, the number of axles specifying unit 254 specifies the number of axles based on the high temperature region RGH (ST04: step of specifying the number of axles).
The order of the above steps can be changed as appropriate. For example, if the predetermined temperature range TP stored in advance in ST02 is acquired, the order of ST01 and ST02 may be reversed.

(Action and effect)
According to the present embodiment, the axle number detection device 25 can specify the region corresponding to the grounded tire TR regardless of the presence or absence of the non-grounded tire TR by specifying the high temperature region RGH. can.
As a result, the axle number detecting device 25 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

If the vehicle is a vehicle with a lift axle mechanism, the vehicle may have tires that are in contact with the tire and tires that are not in contact with the ground.
In such a vehicle, in order to detect the number of axles of a tire that is in contact with the ground as the number of axles, it is necessary to distinguish and detect the tire that is in contact with the tire that is not in contact with the ground.
As a comparative example, as disclosed in Patent Document 1, even if an attempt is made to distinguish between a tire that is in contact with a tire and a tire that is not in contact with the photographed image of the tire taken from the side surface of the vehicle, the tire condition, the surrounding environment, and the photograph are taken. Depending on the position etc., it may not be possible to identify the tire that is in contact with the ground.
On the other hand, in the present embodiment, since the axle number detection device 25 utilizes the difference in temperature between the grounded tire TR and the non-grounded tire, it is easy to identify the grounded tire TR. ..

For example, as shown in FIG. 7, the vehicle AA is a vehicle having a lift axle mechanism, and among the four axle ASs of the vehicle AA, the first axle AS1 of the first axle from the front and the second axle of the second axle are the second axles. It is assumed that the AS2 and the fourth axle AS4 on the fourth axle do not lift up, and the third axle AS3 on the third axle from the front can be lifted up.

When the third axle AS3 becomes the lift-up axis LUS due to lift-up, as shown in FIG. 8, the tire TR included in the third axle AS3 (lift-up axis LUS) is not in contact with the road surface SL. Each tire TR included in the first axle AS1, the second axle AS2, and the fourth axle AS4 is in contact with the road surface SL.
At that time, in the vehicle AA during traveling, the temperature of the tire TR that is in contact with the road surface SL is higher than that of the tire TR that is not in contact with the road surface SL.
Therefore, the region corresponding to each tire TR included in the first axle AS1, the second axle AS2, and the fourth axle AS4 is specified as a high temperature region RGH.
On the other hand, as shown in FIG. 9, the region corresponding to the tire TR included in the third axle AS3 is not specified as the high temperature region RGH.

When not lifted up, as shown in FIG. 10, the tire TR included in the third axle AS3 is the road surface SL, as in the case of each tire TR included in the first axle AS1, the second axle AS2, and the fourth axle AS4. Is in contact with.
Therefore, as shown in FIG. 11, in the vehicle AA during traveling, the tire TR included in the third axle AS3 is used in the same manner as the tire TR included in the first axle AS1, the second axle AS2, and the fourth axle AS4. The corresponding region is identified as the hot region RGH.
In FIGS. 9 and 11, in the temperature distribution information TDI, the low temperature region is shown in black and the high temperature region is shown in white.

Therefore, regardless of the presence or absence of the tire TR that is not in contact with the ground, the axle number detecting device 25 can specify the region corresponding to the tire TR that is in contact with the ground.

Further, according to an example of the present embodiment, since the predetermined temperature range TP is acquired based on the road surface temperature TSL, the predetermined temperature range TP related to the environmental temperature can be acquired.

Further, according to an example of the present embodiment, since the number of axles can be specified from the region having a circular shape or an annular shape in the high temperature region RGH, it is difficult to detect the high temperature region RGH other than the tire TR as the number of axles.

<Second embodiment>
The axle number detecting device 35 according to the second embodiment will be described with reference to the drawings.

The processing unit 33 of the second embodiment is configured and functions in the same manner as the processing unit 23 of the first embodiment except that the processing unit 33 of the second embodiment includes the axle number detecting device 35 instead of the axle number detecting device 25. Is omitted.

As shown in FIG. 12, the toll collection system 101 includes a vehicle detector 102, a communication antenna 3, and a vehicle type determination device 4.
The vehicle detector 102 includes a temperature distribution detection device 22, a photographing device 32, and a processing unit 33.
For example, the vehicle detector 102 may further include a light emitting / receiving device 21.

(Configuration of imaging device)
The photographing device 32 acquires a photographed image IM regarding the side surface of the traveling vehicle AA.
In the present embodiment, the photographing device 32 photographs the side surface of the vehicle AA including the tire TR.
For example, the photographing device 32 may photograph from the roadside and acquire the photographed image IM.

For example, the photographing device 32 may be installed on the island IS.
Further, the photographing device 32 may be installed from the island IS toward the lane LN so that the vehicle AA passing through the approach detection position XA is reflected in the field of view.
Further, the photographing device 32 may be an area scan camera.
Further, the photographing device 32 may be provided adjacent to the temperature distribution detecting device 22 downstream in the lane direction.

(Structure of processing unit)
As shown in FIG. 13, the processing unit 33 includes a detection unit 24 and an axle number detection device 35.
The axle number detection device 35 functionally includes a temperature distribution acquisition unit 351 and a tire region identification unit 352.
For example, the axle number detecting device 35 may further functionally include a captured image acquisition unit 350, a temperature range acquisition unit 353, and an axle number specifying unit 354.
Further, the axle number detection device 35 may notify the vehicle type determination device 4 of the detected number of axles of the vehicle AA.

The captured image acquisition unit 350 acquires a captured image IM regarding the side surface of the traveling vehicle AA.
The captured image acquisition unit 350 acquires the captured image IM from the photographing device 32.

As shown in FIG. 14, the temperature distribution acquisition unit 351 acquires the temperature distribution information TDI regarding the side surface of the traveling vehicle AA.
For example, the temperature distribution acquisition unit 351 may acquire the temperature distribution information TDI from the temperature distribution detection device 22.
In FIG. 14, in the temperature distribution information TDI, the low temperature region is shown in black and the high temperature region is shown in white.

As shown in FIG. 14, the tire region specifying unit 352 identifies the tire region RGT from the photographed image IM regarding the side surface of the traveling vehicle AA.
For example, the tire region specifying unit 352 may specify the tire region RGT from the color, shape, position, etc. in the captured image IM.
For example, the specified tire region RGT may be an annular region sandwiched between the outer circumference and the inner circumference of the tire TR.

The temperature range acquisition unit 353 acquires a predetermined temperature range TP.
For example, the temperature range acquisition unit 353 may acquire the road surface temperature TSL from the temperature distribution information TDI and acquire a predetermined temperature range TP based on the road surface temperature TSL.
At that time, the temperature range acquisition unit 353 may acquire the temperature at the position corresponding to the road surface SL in the temperature distribution information TDI as the road surface temperature TSL. Further, the position corresponding to the road surface SL may be a predetermined position in the temperature distribution information TDI, or may be the position of the road surface SL specified from the color, shape, position, etc. in the captured image IM. good.
The temperature range acquisition unit 353 may acquire a temperature range having a lower limit of the temperature obtained by adding a predetermined temperature difference to the road surface temperature TSL as a predetermined temperature range TP.
At that time, the predetermined temperature difference may be set in advance by measuring the temperature difference between the temperature indicated by the grounded tire TR of the vehicle AA during traveling and the road surface temperature as a sample.

For example, the temperature range acquisition unit 353 may acquire a predetermined temperature range TP stored in advance by the user, or may acquire a predetermined temperature range TP based on an automatic threshold value acquired from a statistical value of the temperature distribution information TDI or the like. May be obtained.

The number of axles specifying unit 354 specifies the number of axles based on the tire region RGT and the temperature distribution information TDI.
For example, the number of axes specifying unit 354 may include a determination unit 354a.
As shown in FIG. 14, the determination unit 354a determines the ground contact tire region RGC of the tire region RGT based on the temperature distribution information TDI located in the tire region RGT.
For example, the determination unit 354a specifies the temperature distribution information TDI included in the position in each tire region RGT, and determines that the tire region RGT including the temperature distribution information TDI belonging to the predetermined temperature range TP is the ground contact tire region RGC. May be good.
In such a determination, the temperature in the tire region RGT can be determined if there is at least one temperature distribution information TDI included in the position in each tire region RGT. Therefore, for example, the number of pixels of the temperature distribution detection device 22 may be smaller than the number of pixels of the photographing device 32.
In the case shown in FIG. 14, since the white position of the temperature distribution information TDI is the temperature distribution information TDI belonging to the predetermined temperature range TP, the first axle AS1, the second axle AS2, and the fourth axle of the vehicle AA Each tire region RGT corresponding to AS4 is determined to be the ground contact tire region RGC.

For example, when the ground contact tire region RGC is determined as described above, the number of axles specifying unit 354 counts the number of ground contact tire region RGCs for the vehicle AA and specifies it as the number of axles.
In the case shown in FIG. 14, since the number of ground contact tire region RGCs for the vehicle AA is 3, the number of axles is specified as “3”.

(motion)
The operation of the axle number detection device 35 of this embodiment will be described.
The operation of the axle number detection device 35 corresponds to the axle number detection method of the present embodiment.

First, as shown in FIG. 15, the photographed image acquisition unit 350 acquires the photographed image IM regarding the side surface of the traveling vehicle AA (ST11: photographed image acquisition step).
Following the implementation of ST11, the temperature distribution acquisition unit 351 acquires the temperature distribution information TDI regarding the side surface of the traveling vehicle AA (ST12: temperature distribution acquisition step).
Following the implementation of ST12, the tire area specifying unit 352 specifies the tire area RGT from the photographed image IM regarding the side surface of the traveling vehicle AA (ST13: tire area specifying step).
Following the implementation of ST13, the temperature range acquisition unit 353 acquires a predetermined temperature range TP (ST14: temperature range acquisition step).
Following the implementation of ST14, the number of axles specifying unit 354 specifies the number of axles based on the tire region RGT and the temperature distribution information TDI (ST15: step of specifying the number of axles).
For example, in ST15, the determination unit 354a may determine the ground contact tire region RGC in the tire region RGT based on the temperature distribution information TDI located in the tire region RGT (ST15a: determination step).

The order of the above steps can be changed as appropriate.
For example, the order of ST11 and ST12 may be reversed or may be simultaneous.
For example, ST13 may be performed in any order as long as it is after ST11 and before ST15.
For example, ST14 may be performed in any order as long as it is after ST12 and before ST15.

(Action and effect)
According to the present embodiment, in addition to the points shown in the first embodiment, the axle number detecting device 35 can specify the number of axles based on the tire region RGT and the temperature distribution information TDI, so that the tire TR that is in contact with the ground can be specified. A related tire region RGT and a tire region RGT related to a tire TR that is not in contact with the ground can be distinguished.
As a result, the axle number detecting device 35 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

In one example of the present embodiment, the determination unit 354a determines that the tire region RGT including the temperature distribution information TDI belonging to the predetermined temperature range TP is the ground contact tire region RGC, but the temperature distribution information located in the tire region RGT. If it can be determined based on TDI, it may be determined in any way.
As a modification, the determination unit 354a compares the temperatures of the plurality of tire regions RGTs of the vehicle AA based on the average value, the representative value, etc. of the temperature distribution information TDI related to each tire region RGT, and compares the temperatures of the plurality of tire regions RGTs of the vehicle AA, and the tire region having a high temperature. The RGT may be determined as the ground contact tire region RGC.
As another modification, the determination unit 354a determines the tire region RGT related to the first axle AS1 (or the second axle AS2) based on the average value, the representative value, etc. of the temperature distribution information TDI related to each tire region RGT. The tire region RGT excluding the tire region RGT having a low temperature may be determined as the ground contact tire region RGC based on the temperature.
As yet another modification, the determination unit 354a determines the tire region RGT related to the first axle AS1 (or the second axle AS2) based on the average value, the representative value, etc. of the temperature distribution information TDI related to each tire region RGT. The tire region RGT having the same temperature may be determined to be the ground tire region RGC based on the temperature of.

In one example of the present embodiment, the case where the photographing device 32 is an area scan camera has been described, but any device may be used as long as it can photograph the vehicle AA passing through the approach detection position XA.
As a modification, the photographing device 32 may be a line scan camera.
At that time, the photographing device 32 may photograph the vicinity of the downstream side or the upstream side of the approach detection position XA, or may photograph the approach detection position XA.
However, when photographing the approach detection position XA, it is necessary to ground the line scan camera so that the installation position of the line scan camera and the installation position of the light emitting / receiving device 21 do not interfere with each other.
For example, at the approach detection position XA, a reflective light emitting / receiving device 21 may be provided on one road side and a line scan camera may be provided on the other road side so as not to interfere with each other.

In one example of the present embodiment, the temperature distribution detection device 22 and the photographing device 32 are provided separately, but any configuration may be used as long as the temperature distribution information TDI and the photographed image IM can be acquired.
As a modification, the multispectral camera may be shared as the temperature distribution detection device 22 and the photographing device 32.
At that time, the multispectral camera detects infrared rays to acquire temperature distribution information TDI, and detects visible light to acquire a captured image IM.

<Modification example>
In one example of each of the above-described embodiments, the case where the temperature distribution detection device 22 is an area scan type thermal camera has been described, but any device can detect the temperature distribution of the vehicle AA passing through the approach detection position XA. It may be.
As a modification, the temperature distribution detection device 22 may be a line scan type thermal camera.
At that time, the temperature distribution detection device 22 may detect in the vicinity of the downstream side or the upstream side of the approach detection position XA, or may detect in the approach detection position XA.
However, when detecting at the approach detection position XA, it is necessary to install the line scan type thermal camera so that the installation position and the light emitting / receiving device 21 installation position do not interfere with each other.
For example, at the approach detection position XA, a reflective light emitting / receiving device 21 may be provided on one road side and a line scan type thermal camera may be provided on the other road side so as not to interfere with each other.

In each of the above-described embodiments, the axle number detection devices 25 and 35 are provided in the electronic toll collection system, but may be provided in any system.
As a modification, the axle number detection device 25 may be provided in a system including an automatic toll collection machine.
As another modification, the axle number detection devices 25 and 35 may be provided at a manned tollhouse where tolls are collected by a tollhouse.

In each of the above-described embodiments, the axle number detection devices 25 and 35 are provided in the vehicle detectors 2 and 102, but they may be provided in any form.
As a modification, the axle number detection devices 25 and 35 may be provided in the vehicle type determination device 4.
As another modification, the axle number detection devices 25 and 35 may be independent devices provided separately from the vehicle detectors 2 and 102 and the vehicle type determination device 4.

In each of the above-described embodiments, the axle number detection devices 25 and 35 are applied to the separate lane type toll collection systems 1 and 101 installed in the island IS, but as a modification, the axle number detection devices 25 and 35 are applied. May be applied to a free-flow toll collection system.

In each of the above-described embodiments, a program for realizing various functions of the axle number detection devices 25 and 35 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is referred to as a microcomputer. Various processes are performed by loading it into a computer system and executing it. Here, the processes of various processes of the CPU of the computer system are stored in a computer-readable recording medium in the form of a program, and the various processes are performed by the computer reading and executing this program. The computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Further, this computer program may be distributed to a computer via a communication line, and the computer receiving the distribution may execute the program.

In each of the above-described embodiments, an example of a computer hardware configuration for executing a program for realizing various functions of the axle number detection devices 25 and 35 will be described.

As shown in FIG. 16, the computers 40 included in the axle number detection devices 25 and 35 include a CPU 41, a memory 42, a storage / playback device 43, and an Input Output Interface (hereinafter referred to as “IO I / F”) 44. And a communication interface (hereinafter, referred to as "communication I / F") 45.

The memory 42 is a medium such as a Random Access Memory (hereinafter referred to as “RAM”) that temporarily stores data or the like used in a program executed by the axle number detecting devices 25 and 35.
The storage / playback device 43 is a device for storing data or the like in an external medium such as a CD-ROM, a DVD, or a flash memory, or playing back data or the like on the external media.
The IO I / F44 is an interface for inputting / outputting information and the like between the axle number detecting devices 25 and 35 and other devices.
The communication I / F 45 is an interface for communicating with other devices via a communication line such as the Internet or a dedicated communication line.

<Other Embodiments>
Although some embodiments of the present disclosure have been described above, these embodiments are presented as examples and are not intended to limit the scope of the present disclosure. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the present disclosure. These embodiments and variations thereof are included in the scope and gist of the disclosure.

<Additional notes>
The axle number detection device, the toll collection system, the axle number detection method, and the program described in each embodiment are grasped as follows, for example.

(1) The axle number detection device 25 according to the first aspect has a temperature distribution acquisition unit 251 that acquires temperature distribution information TDI regarding the side surface of the traveling vehicle AA, and a temperature range acquisition unit 252 that acquires a predetermined temperature range TP. In the temperature distribution information TDI, a high temperature region specifying unit 253 that specifies the high temperature region RGH that belongs to the predetermined temperature range TP, and an axle number specifying unit that specifies the number of axles based on the high temperature region RGH. 254 and.

According to this aspect, the axle number detection device 25 can specify the region corresponding to the grounded tire TR regardless of the presence or absence of the non-grounded tire TR by specifying the high temperature region RGH. ..
As a result, the axle number detecting device 25 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

(2) In the axle number detecting device 25 according to the second aspect, the axle number specifying unit 254 specifies the number of axles from a region having a circular shape or an annular shape in the high temperature region RGH (1). 25. The number of axles detecting device 25.

According to this aspect, since the number of axles can be specified from the region having a circular shape or an annular shape in the high temperature region RGH, it is difficult to detect the high temperature region RGH other than the tire TR as the number of axles.

(3) In the axle number detection device 25 according to the third aspect, the temperature range acquisition unit 252 acquires the road surface temperature TSL from the temperature distribution information TDI, and based on the road surface temperature TSL, the predetermined temperature range TP. The number of axles detecting device 25 according to (1) or (2).

According to this aspect, since the predetermined temperature range TP is acquired based on the road surface temperature TSL, the predetermined temperature range TP related to the environmental temperature can be acquired.

(4) The axle number detection device 35 according to the fourth aspect identifies the tire region RGT from the temperature distribution acquisition unit 351 that acquires the temperature distribution information TDI regarding the side surface of the traveling vehicle AA and the photographed image IM regarding the side surface. The tire region specifying unit 352 is provided, and the number of axles specifying unit 354 that specifies the number of axles based on the tire region RGT and the temperature distribution information TDI.

According to this aspect, since the axle number detection device 35 can specify the number of axles based on the tire region RGT and the temperature distribution information TDI, the tire region RGT related to the grounded tire TR and the non-grounded tire The tire region RGT associated with TR can be identified.
As a result, the axle number detecting device 35 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

(5) The toll collection systems 1 and 101 according to the fifth aspect include the axle number detecting devices 25 and 35 according to any one of (1) to (4) and the temperature distribution detection for detecting the temperature distribution information TDI. The device 22 is provided.

According to this aspect, the toll collection system 1 can specify the region corresponding to the grounded tire TR regardless of the presence or absence of the non-grounded tire TR by specifying the high temperature region RGH.
Alternatively, according to this aspect, since the toll collection system 101 can specify the number of axles based on the tire region RGT and the temperature distribution information TDI, the tire region RGT related to the grounded tire TR and the non-grounded tire The tire region RGT associated with TR can be identified.
As a result, the toll collection systems 1 and 101 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

(6) The method for detecting the number of axles according to the sixth aspect is the step of acquiring the temperature distribution information TDI regarding the side surface of the traveling vehicle AA, the step of acquiring the predetermined temperature range TP, and the temperature distribution information. It includes a step of specifying a high temperature region RGH which is a region belonging to the predetermined temperature range TP, and a step of specifying the number of axles based on the high temperature region RGH.

According to this aspect, the method for detecting the number of axles can specify a region corresponding to a tire TR that is in contact with the ground regardless of the presence or absence of the tire TR that is not in contact with the ground by specifying the high temperature region RGH.
As a result, the method for detecting the number of axles can specify the number of axles of the tire TR that comes into contact with the ground, so that it is difficult to erroneously detect the number of axles of the tire TR that comes into contact with the ground.

(7) The method for detecting the number of axles according to the seventh aspect includes a step of acquiring temperature distribution information TDI regarding the side surface of the traveling vehicle AA, a step of specifying the tire region RGT from the photographed image IM related to the side surface, and the above. It includes a step of specifying the number of axles based on the tire region RGT and the temperature distribution information TDI.

According to this aspect, since the number of axles detection method can specify the number of axles based on the tire region RGT and the temperature distribution information TDI, the tire region RGT related to the grounded tire TR and the non-grounded tire TR The tire region RGT associated with can be identified.
As a result, the method for detecting the number of axles can specify the number of axles of the tire TR that comes into contact with the ground, so that it is difficult to erroneously detect the number of axles of the tire TR that comes into contact with the ground.

(8) The program according to the eighth aspect includes a step of acquiring temperature distribution information TDI regarding the side surface of the traveling vehicle AA, a step of acquiring a predetermined temperature range TP, and a step of acquiring the computer 40 of the axle number detection device 25. In the temperature distribution information TDI, a step of specifying a high temperature region RGH which is a region belonging to the predetermined temperature range TP and a step of specifying the number of axles based on the high temperature region RGH are executed.

According to this aspect, the axle number detection device 25 can specify the region corresponding to the grounded tire TR regardless of the presence or absence of the non-grounded tire TR by specifying the high temperature region RGH. ..
As a result, the axle number detecting device 25 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

(9) The program according to the ninth aspect is the tire region RGT from the step of acquiring the temperature distribution information TDI regarding the side surface of the traveling vehicle AA on the computer 40 of the axle number detection device 35 and the photographed image IM relating to the side surface. And the step of specifying the number of axles based on the tire region RGT and the temperature distribution information TDI.

According to this aspect, since the axle number detection device 35 can specify the number of axles based on the tire region RGT and the temperature distribution information TDI, the tire region RGT related to the grounded tire TR and the non-grounded tire The tire region RGT associated with TR can be identified.
As a result, the axle number detecting device 35 can specify the number of axles of the tire TR to be grounded, so that it is difficult to erroneously detect the number of axles of the tire TR to be grounded.

1 Toll collection system 2 Vehicle detector 3 Communication antenna 4 Vehicle type discriminator 21 Projection receiver 21A Floodlight 21B Receiver 22 Temperature distribution detection device 23 Processing unit 24 Detection unit 25 Axle number detection device 32 Imaging device 33 Processing unit 35 Axle number detection Device 40 Computer 41 CPU
42 Memory 43 Storage / playback device 44 IO I / F
45 Communication I / F
101 Toll collection system 102 Vehicle detector 251 Temperature distribution acquisition unit 252 Temperature range acquisition unit 253 High temperature area identification unit 254 Axis number specification unit 350 Photographed image acquisition unit 351 Temperature distribution acquisition unit 352 Tire area specification unit 353 Tire area acquisition unit 354 Axis Number Identification Unit 354a Judgment Unit AA Vehicle AS Axle AS1 1st Axle AS2 2nd Axle AS3 3rd Axle AS4 4th Axle DS Light Detection Signal IM Photographed Image IS Island LN Axle LUS Lift Up Axis RGC Grounding Tire Area RGH High Temperature Area RGT Tire Area SL Road surface TDI Temperature distribution information TP Temperature range TR Tire TSL Road surface temperature XA Approach detection position α In-vehicle device

Claims (9)

A temperature distribution acquisition unit that acquires temperature distribution information related to the side surface of the traveling vehicle,
A temperature range acquisition unit that acquires a predetermined temperature range, and
Of the temperature distribution information, a high temperature region specifying portion that specifies a high temperature region that belongs to the predetermined temperature range, and
Based on the high temperature region, the number of axles specifying part that specifies the number of axles,
Axle number detection device equipped with. The axle number detecting device according to claim 1, wherein the axle number specifying unit specifies the number of axles from a region having a circular shape or an annular shape in the high temperature region. The axle number detection device according to claim 1 or 2, wherein the temperature range acquisition unit acquires the road surface temperature from the temperature distribution information and acquires the predetermined temperature range based on the road surface temperature. A temperature distribution acquisition unit that acquires temperature distribution information related to the side surface of the traveling vehicle,
From the photographed image of the side surface, the tire area specifying portion for specifying the tire area and the tire area specifying portion
An axle number specifying unit that specifies the number of axles based on the tire region and the temperature distribution information,
Axle number detection device equipped with. The axle number detection device according to any one of claims 1 to 4.
A temperature distribution detection device that detects the temperature distribution information,
A toll collection system equipped with. Steps to acquire temperature distribution information about the side of the traveling vehicle,
Steps to get a given temperature range and
In the temperature distribution information, a step of specifying a high temperature region which is a region belonging to the predetermined temperature range, and
The step of specifying the number of axles based on the high temperature region and
Axle number detection method including. Steps to acquire temperature distribution information about the side of the traveling vehicle,
The step of identifying the tire area from the photographed image of the side surface, and
A step of specifying the number of axles based on the tire region and the temperature distribution information,
Axle number detection method including. To the computer of the axle number detection device,
Steps to acquire temperature distribution information about the side of the traveling vehicle,
Steps to get a given temperature range and
In the temperature distribution information, a step of specifying a high temperature region which is a region belonging to the predetermined temperature range, and
The step of specifying the number of axles based on the high temperature region and
A program that executes. To the computer of the axle number detection device,
Steps to acquire temperature distribution information about the side of the traveling vehicle,
The step of identifying the tire area from the photographed image of the side surface, and
A step of specifying the number of axles based on the tire region and the temperature distribution information,
A program that executes.

Images