JP2012234251A - Vehicle detection system and vehicle detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect a passing vehicle without using a multiple optical axial transmissive sensor or a non-contact axle sensor.SOLUTION: A vehicle detection start sensor 121 is disposed at a front side in a passing direction of a passing vehicle 110 and a vehicle detection end sensor 122 is disposed at a rear side in the passing direction of the passing vehicle 110. Further, an axle detection sensor 123 and a vehicle upper portion detection sensor 124 are disposed between the vehicle detection start sensor 121 and the vehicle detection end sensor 122. The vehicle detection start sensor 121 and the axle detection sensor 123 are dispose at a medium height to detect a traction bar attached a vehicle body or bottom of the vehicle body of the passing vehicle 110. The axle detection sensor 123 is disposed at a lower position to detect a tire of the passing vehicle 110 as an axle of the passing vehicle 110. The vehicle upper portion detection sensor 124 is dispose at a higher position to detect a traction bar attached to an upper portion of the vehicle body of the passing vehicle 110.

Description

  The present invention relates to a vehicle detection system and a vehicle detection method for detecting a vehicle, for example.

  There is a system in which a vehicle detection device that detects a passing vehicle and determines the type of vehicle is installed at a toll gate on a toll road and automatically charges a toll based on the determination result.

The vehicle detection device needs to detect the vehicle length, the vehicle width, the number of axles, the presence / absence of traction, and so on, and therefore uses a number of sensors in combination.
For example, a sensor that measures the distance to a reflective object by receiving (reflecting) laser light and receiving light reflected by an object that exists in the direction of emission is used. By changing the radiation direction of the laser light using such a sensor, the shape of the reflecting object can be measured.

  In order to instantaneously and accurately detect a vehicle traveling at high speed, it is necessary to change the radiation direction of the laser light at high speed. Therefore, one-dimensional scanning is effective for laser light scanning, not two-dimensional scanning. .

In addition, there are two methods for emitting laser light: a continuous wave (CW: continuous wave) laser light and a method for emitting laser light, and a method for emitting pulsed laser light, each of which has advantages and disadvantages.
Hereinafter, a sensor that emits continuous wave (CW) laser light is referred to as a “CW laser”, and a sensor that emits pulsed laser light is referred to as a “pulse laser”.

  A CW laser or a pulse laser detects a distance from an object based on a time from when a continuous wave or pulse wave laser beam is emitted until a reflected wave is received.

The CW laser has a fast repeated scanning speed. That is, since the CW laser detects light reception continuously during the transmission (radiation) of the laser light, high-density detection is possible.
However, the continuous wave laser beam has a higher average power than the pulsed laser beam, and the CW laser cannot transmit the laser beam at a high power due to the safety standard and the rating of the laser diode. For this reason, the CW laser has a shorter maximum detection distance than the pulse laser.
Further, in order to extend the detection distance by sending laser light with low power, it is necessary to increase the aperture diameter of the lens to improve the light receiving sensitivity. However, when the aperture diameter of the lens is increased, the viewing angle becomes narrower depending on the relationship with the focal length. On the contrary, when the viewing angle is widened, the light receiving sensitivity is deteriorated and the detection performance is lowered.

The pulse laser can instantaneously transmit a laser beam having a large power while suppressing the average power of the laser beam by a pulse wave. For this reason, the pulse laser can detect an object at a long distance.
However, pulsed lasers have a slow scanning speed and a low laser beam irradiation density, so it is difficult to detect fast moving objects and small objects.

JP-A-10-260025 JP 2001-175899 A

Patent Document 1 discloses a method for detecting a vehicle using a pulse laser.
In this method, since a pulse laser is used, the irradiation density of laser light is rough, and it is technically difficult to detect a thin object such as a tow bar. Further, when the irradiation density of laser light is made fine, the time required to scan the width direction of the road becomes long, and it becomes difficult to detect a vehicle traveling at high speed.
Further, since the number of laser spots irradiated to the tire is small in the pulse laser, it is determined whether the received laser beam is a laser beam reflected on the tire or a laser beam reflected on a portion other than the tire of the vehicle. Is difficult. For this reason, the detection accuracy of the number of axles cannot be expected.

Patent Document 2 discloses a method of detecting a vehicle by combining a multi-optical axis transmission type sensor and a contact type axle sensor.
In this system, it is necessary to prepare a sensor for receiving laser light in addition to a device for transmitting light as a device constituting the multi-optical axis transmission type sensor.
In this method, it is necessary to embed a contact-type axle sensor on the roadway. Furthermore, since the contact-type axle sensor is a consumable item, replacement costs are incurred.

  An object of the present invention is to make it possible to correctly detect a passing vehicle without using, for example, a multi-optical axis transmission type sensor or a contact type axle sensor.

The vehicle detection system of the present invention is
A vehicle detection sensor that is installed at a predetermined height beside the road, emits a laser beam from the road side toward the road surface, and receives the laser beam reflected by a passing vehicle passing through the road;
An axle detection sensor that is installed at a position lower than the vehicle detection sensor, emits radar light toward a road surface, and receives laser light reflected on a tire of the passing vehicle.

  According to the present invention, for example, a passing vehicle can be correctly detected without using a multi-optical axis transmission sensor or a contact type axle sensor.

1 is an external view of a toll fee charging system 100 according to Embodiment 1. FIG. FIG. 3 is a plan view showing the positional relationship of the laser sensor in the first embodiment. FIG. 3 is a front view showing the positional relationship of the laser sensor in the first embodiment. FIG. 3 shows an example of dimensions of a detection area 101 in the first embodiment. FIG. 3 is a relationship diagram between a measurement region of the laser sensor and the tow vehicle 111 in the first embodiment. FIG. 3 is a relationship diagram between a measurement region of the laser sensor and the tow vehicle 111 in the first embodiment. FIG. 2 is a functional configuration diagram of a vehicle detection device 200 in the first embodiment. 4 is a flowchart showing a vehicle detection process of a vehicle detection unit 210 in the first embodiment. 4 is a flowchart showing axle detection processing of an axle detection unit 220 in the first embodiment. 4 is a table showing a determination order of forward / reverse determination processing by the forward / reverse determination unit 230 according to the first embodiment. FIG. 6 is a front view showing another example of the positional relationship of the laser sensor in the first embodiment. FIG. 3 is a diagram illustrating an example of hardware resources of the vehicle detection device 200 according to the first embodiment. The function block diagram of the vehicle detection apparatus 200 in Embodiment 2. FIG.

Embodiment 1 FIG.
A mode in which a plurality of laser sensors are installed at different heights to detect a passing vehicle will be described.

FIG. 1 is an external view of a toll fee charging system 100 according to the first embodiment.
An outline of the toll fee charging system 100 according to the first embodiment (an example of a vehicle detection method) will be described with reference to FIG.

  The toll fee charging system 100 (an example of a vehicle detection system) is a system that detects a toll vehicle 110 passing through a road and charges the toll for the detected toll vehicle 110.

The passing vehicle 110 may be any type of vehicle such as a small vehicle, a large vehicle, a two-wheeled vehicle, a four-wheeled vehicle, a six-wheeled vehicle, and a towing vehicle.
A towing vehicle is a vehicle that has a tow bar on a vehicle body and that pulls a vehicle or a truck connected to the tow bar. Hereinafter, a vehicle or a truck towed by a tow vehicle is referred to as a “towed vehicle”.

The toll fee charging system 100 includes four laser sensors (reference numerals 121 to 124) for detecting a passing vehicle 110 passing through a road. Four laser sensors are installed on the side of the road (roadside).
The toll charging system 100 includes a vehicle detection device 200 (not shown) that detects the toll vehicle 110 based on the measurement results of the four laser sensors.
Furthermore, the toll fee charging system 100 includes a roadside radio device 130 that communicates wirelessly with the vehicle-mounted device of the toll vehicle 110 and a toll collection device 140 that charges a toll fee (all not shown).

For example, the roadside radio device 130 and the toll collection device 140 constitute an ETC system (ETC: Electronic Toll Collection) of a toll road tollgate.
In this case, the four laser sensors are installed in front of the toll booth.

The laser sensor emits laser light (radiated light) repeatedly from the front side in the width direction of the road to the back side and from the back side in the width direction of the road to the front side while repeating the laser light toward the road surface. Radiate. The measurement area where the laser beam is emitted is shown by shading.
The laser sensor receives the laser beam reflected by the passing vehicle 110 when the passing vehicle 110 passes forward. Further, when the passing vehicle 110 is not passing forward, the laser sensor receives laser light (reflected light) reflected on the road surface.
The laser sensor measures the time from when the laser beam is emitted until the laser beam is received, and measures (detects) the distance from the road surface or the passing vehicle 110 based on the measured time.

Hereinafter, the laser beam emission and reception are repeated while changing the laser beam emission angle from the front side to the back side in the width direction of the road and from the back side to the front side in the width direction of the road. Scanning.
A reciprocating scan that scans from the near side in the width direction of the road to the far side and scans from the far side in the width direction of the road to the near side is referred to as “one scan”. However, the forward scan from the near side to the far side in the width direction of the road, or the return scan (one-way scan) that scans from the far side to the near side in the width direction of the road may be referred to as “one scan”. .

  Next, the positional relationship between the four laser sensors (reference numerals 121 to 124) will be described.

FIG. 2 is a plan view showing the positional relationship of the laser sensor in the first embodiment.
The positional relationship of the four laser sensors (reference numerals 121 to 124) with respect to the traveling direction of the passing vehicle 110 will be described with reference to FIG.

  The measurement area (measurement line) where the laser light is emitted is shaded.

The vehicle detection start sensor 121 (an example of a first vehicle detection sensor) is a laser sensor that is installed on the most front side in the traveling direction of the passing vehicle 110 among the four laser sensors.
The vehicle detection end sensor 122 (an example of a second vehicle detection sensor) is a laser sensor installed on the farthest side in the traveling direction of the passing vehicle 110 among the four laser sensors.
The axle detection sensor 123 (an example of an axle detection sensor) and the upper vehicle detection sensor 124 (an example of a third vehicle detection sensor) are laser sensors installed between the vehicle detection start sensor 121 and the vehicle detection end sensor 122. . That is, the axle detection sensor 123 and the upper vehicle detection sensor 124 are located on the far side of the traveling direction of the passing vehicle 110 with respect to the vehicle detection start sensor 121, and in the traveling direction of the passing vehicle 110 with respect to the vehicle detection end sensor 122. It is installed at a point located on the near side.

The interval between the vehicle detection start sensor 121 and the vehicle detection end sensor 122 is preferably about 80 centimeters or more. This is to prevent the vehicle detection start sensor 121 and the vehicle detection end sensor 122 from simultaneously detecting the same passerby (or other than the passing vehicle 110).
The distance between the vehicle detection start sensor 121 and the vehicle detection end sensor 122 is preferably about 150 centimeters or less. This is because the vehicle detection end sensor 122 can detect the passing vehicle 110 before the passing vehicle 110 passes through the measurement region of the vehicle detection start sensor 121.

The vehicle detection start sensor 121 and the vehicle detection end sensor 122 may be installed on the opposite side of the road (road side) across the road. That is, the vehicle detection end sensor 122 may be installed on the opposite side of the road where the vehicle detection start sensor 121 is installed. This is because the passing vehicle 110 can be detected in a wider area.
The axle detection sensor 123 and the upper vehicle detection sensor 124 may be installed on either side of the road on the side where the vehicle detection start sensor 121 is installed or on the side of the road where the vehicle detection end sensor 122 is installed. Good.
However, the vehicle detection start sensor 121 and the vehicle detection end sensor 122 may be installed on the same side of the road, or on the side of the road where neither the vehicle detection start sensor 121 nor the vehicle detection end sensor 122 is installed. An axle detection sensor 123 and an upper vehicle detection sensor 124 may be installed.

FIG. 3 is a front view showing the positional relationship of the laser sensor in the first embodiment.
The height at which the laser sensor (reference numerals 121-124) is installed will be described with reference to FIG.

The “detection area 101” is shown as a target area for detecting the passing vehicle 110, and the range of the measurement area where the laser beam is emitted is shown by a dotted line. The detection area 101 is included in the measurement region of at least one of the laser sensors (reference numerals 121 to 124).
Also, a “lower tow bar 112” provided at the lower part of the tow vehicle body and an “upper tow bar 113” provided at the upper part of the tow car body are shown in the detection area 101.

The vehicle detection start sensor 121 and the vehicle detection end sensor 122 are installed at a medium height of the four laser sensors.
The height at which the vehicle detection start sensor 121 and the vehicle detection end sensor 122 are installed detects the vehicle body (including the front end portion and the rear end portion) of the passing vehicle 110 and also detects the lower tow bar 112 of the towing vehicle. It is high enough to be able to.

The axle detection sensor 123 is installed at the lowest position among the four laser sensors.
The height at which the axle detection sensor 123 is installed is high enough to detect the tire of the passing vehicle 110.

The upper vehicle detection sensor 124 is installed at the highest position among the four laser sensors.
The height at which the upper vehicle detection sensor 124 is installed is high enough to detect the upper tow bar 113 of the tow vehicle.

FIG. 4 is a diagram illustrating an example of dimensions of the detection area 101 according to the first embodiment.
The dimension of the detection area 101 in Embodiment 1 is demonstrated based on FIG.

  The detection area 101 shown in FIG. 4 is an area having a height of 2000 millimeters from the road surface and a width of 3500 millimeters.

Hereinafter, a region whose height from the road surface is, for example, up to 500 millimeters is referred to as “F15 detection area 102”.
Further, an area having a height from the road surface of 500 millimeters to 1750 millimeters is referred to as “F50 detection area 103”.

The F15 detection area 102 is an area indicating a range where the lower tow bar 112 is attached, that is, a target area for detecting the lower tow bar 112. The diameter of the lower tow bar 112 is about 15 millimeters, and in the F15 detection area 102, it is necessary to detect an object having a diameter of about 15 millimeters or more.
The F50 detection area 103 is an area indicating a range where the upper tow bar 113 is attached, that is, a target area for detecting the upper tow bar 113. The diameter of the upper tow bar 113 is about 50 millimeters, and it is necessary to detect an object having a diameter of about 50 millimeters or more in the F50 detection area 103.

  The depth range of the detection area 101 is a range from the measurement region of the vehicle detection start sensor 121 to the measurement region of the vehicle detection end sensor 122.

The vehicle detection start sensor 121 and the vehicle detection end sensor 122 (see FIG. 3) receive the laser beam reflected in the measurement region by radiating the laser beam to the measurement region with the region including the F15 detection area 102 as the measurement region. Install at the height to be used.
For example, the F15 detection area 102 is set as a target area of the vehicle detection start sensor 121 and the vehicle detection end sensor 122.

The upper vehicle detection sensor 124 (see FIG. 3) is installed at a height at which the region including the F50 detection area 103 is set as a measurement region and laser light is emitted to the measurement region and the laser beam reflected in the measurement region is received. .
For example, the F50 detection area 103 is set as a target area of the upper vehicle detection sensor 124.

The dimensions of the detection area 101 shown in FIG. 4 are an example of the embodiment, and the detection area 101 may be larger or smaller than the area shown in FIG.
For example, the width of the detection area 101 is the same as or approximately the same as the width of the road. That is, when the width of the road is 4000 mm, the lateral width of the detection area 101 is set to about 4000 mm.

Next, the types of laser light emitted by the four laser sensors (reference numerals 121 to 124) will be described.
The vehicle detection start sensor 121, the vehicle detection end sensor 122, and the axle detection sensor 123 emit continuous wave (CW: continuous wave) laser light. This is to increase detection accuracy. However, a pulsed laser beam may be emitted.
The upper vehicle detection sensor 124 emits a pulse wave or continuous wave laser beam. This is because the main purpose of the upper vehicle detection sensor 124 is to detect the upper tow bar 113 which is larger than the lower tow bar 112, so that the detection resolution may be slightly lower.

5 and 6 are diagrams showing the relationship between the measurement area of the laser sensor and the tow vehicle 111 in the first embodiment.
The relationship between the measurement region of the laser sensor and the tow vehicle 111 in the first embodiment will be described with reference to FIGS.

5 and 6 show a towed vehicle 111 that pulls the towed vehicle 119 using a tow bar (reference numerals 112 and 113).
In addition, the “measurement region 121a” of the vehicle detection start sensor 121, the “measurement region 122a” of the vehicle detection end sensor 122, the “measurement region 123a” of the axle detection sensor 123, and the “measurement region 124a” of the upper vehicle detection sensor 124. ".

As shown in FIG. 5, when a tow vehicle 111 that pulls the towed vehicle 119 using the lower tow bar 112 passes, the vehicle detection start sensor 121 and the vehicle detection end sensor 122 cause the vehicle body (the front end portion and the tow vehicle 111 to move). Including the rear end portion).
Furthermore, the lower tow bar 112 attached to the tow vehicle 111 can be detected by the vehicle detection start sensor 121 and the vehicle detection end sensor 122.
Further, the tire of the towing vehicle 111 can be detected by the axle detection sensor 123.

As shown in FIG. 6, when the tow vehicle 111 that pulls the towed vehicle 119 using the upper tow bar 113 passes, the vehicle detection start sensor 121 and the vehicle detection end sensor 122 cause the vehicle body (the front end portion and Including the rear end portion).
Further, the upper tow bar 113 attached to the tow vehicle 111 can be detected by the upper vehicle detection sensor 124.
Further, the tire of the towing vehicle 111 can be detected by the axle detection sensor 123.

FIG. 7 is a functional configuration diagram of the vehicle detection device 200 according to the first embodiment.
A functional configuration of the vehicle detection device 200 according to Embodiment 1 will be described with reference to FIG.

  The vehicle detection device 200 (an example of a vehicle detection device) includes a vehicle detection unit 210, an axle detection unit 220, a forward / reverse determination unit 230, and a detection device storage unit 290.

The detection device storage unit 290 stores data used by the vehicle detection device 200.
The scan data 291 and the number of axles 292 are examples of data stored in the detection device storage unit 290.

  The number of axles 292 is calculated by the axle detection unit 220.

The scan data 291 is measurement data obtained by one scan by the laser sensor (reference numerals 121 to 124). Measurement data of the round trip (or one way) in the width direction of the road is obtained by one scan.
The laser sensor measures the distance to the reflection point where the laser beam is reflected for each emitted laser beam, and “scanning data 291” includes data including a plurality of distances measured by one scan for each scan. Output as.
Hereinafter, the reflection point where the laser beam is reflected is “measurement point”, the measured distance is “measurement distance”, the time when the distance is measured (for example, the time when the laser beam is emitted or received) is “measurement time”, The radiation angle is called “measurement angle”.

  For example, the scan data 291 indicates a measurement time, a measurement distance, and a measurement angle in association with each measurement point.

The vehicle detection unit 210 determines whether or not the vehicle detection start sensor 121 is detecting the passing vehicle 110 based on the scanning data 291 of the vehicle detection start sensor 121.
The vehicle detection unit 210 determines whether the vehicle detection end sensor 122 has detected the passing vehicle 110 based on the scanning data 291 of the vehicle detection end sensor 122.

The axle detection unit 220 detects whether the axle detection sensor 123 is based on the scanning data 291 of the axle detection sensor 123 while at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122 detects the passing vehicle 110. It is determined whether the axle (tire) of the passing vehicle 110 is detected.
The axle detection unit 220 detects the number of times the axle detection sensor 123 detects the axle (tire) of the passing vehicle 110 while at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122 detects the passing vehicle 110. Count as the number of axles 292 of the passing vehicle 110.

FIG. 8 is a flowchart showing the vehicle detection process of the vehicle detection unit 210 in the first embodiment.
The vehicle detection process of the vehicle detection part 210 in Embodiment 1 is demonstrated based on FIG.

  In S <b> 110, the vehicle detection unit 210 inputs the scan data 291 output from the vehicle detection start sensor 121, and determines whether the vehicle detection start sensor 121 detects the passing vehicle 110 based on the input scan data 291. judge.

At this time, the vehicle detection unit 210 compares the measured distance included in the scan data 291 with a predetermined vehicle detection threshold. For example, the measurement angle and the vehicle detection threshold are associated with each measurement angle and stored in advance in the detection device storage unit 290. And the vehicle detection part 210 compares a vehicle detection threshold value with a measurement distance for every measurement angle.
The vehicle detection unit 210 determines that the vehicle detection start sensor 121 detects the passing vehicle 110 when the scan data 291 includes a measurement distance (a predetermined number or more) that is shorter than the vehicle detection threshold. .

The vehicle detection threshold is a design value corresponding to the distance between the vehicle detection start sensor 121 (or the vehicle detection end sensor 122) and the road surface of the road.
Therefore, when the passing vehicle 110 passes in front of the vehicle detection start sensor 121, the measured distance is shorter than the vehicle detection threshold.
That is, when the laser beam reflected on the vehicle body of the passing vehicle 110 is “vehicle body reflected light”, the measurement distance when the vehicle body reflected light is received is shorter than the vehicle detection threshold. Receiving the vehicle body reflected light means detecting the passing vehicle 110.

  It progresses to S111 after S110.

In S <b> 111, the vehicle detection unit 210 receives the scan data 291 output from the vehicle detection end sensor 122, and determines whether the vehicle detection end sensor 122 detects the passing vehicle 110 based on the input scan data 291. Determine (similar to S110).
It progresses to S112 after S111.

In S112, the vehicle detection unit 210 determines whether at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122 detects the passing vehicle 110 based on the determination result in S110 and the determination result in S111. Determine.
When at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122 detects the passing vehicle 110 (YES), the process proceeds to S113.
When neither the vehicle detection start sensor 121 nor the vehicle detection end sensor 122 has detected the passing vehicle 110 (NO), the process returns to S110.

In S113, the vehicle detection unit 210 outputs (transmits) a vehicle detection signal (or data) indicating that the passing vehicle 110 is passing the detection area 101 to the roadside apparatus 130.
After S113, the process returns to S110.

  The vehicle detection process (S111-S113) is repeatedly executed.

In the vehicle detection process (S111 to S113), the vehicle detection unit 210 may determine whether or not the upper vehicle detection sensor 124 detects the passing vehicle 110.
In this case, the vehicle detection unit 210 outputs a vehicle detection signal when at least one of the vehicle detection start sensor 121, the vehicle detection end sensor 122, and the upper vehicle detection sensor 124 detects the passing vehicle 110.

When a vehicle detection signal is output from the vehicle detection unit 210, the roadside wireless device 130 and the toll collection device 140 perform the following processing, for example.
The roadside apparatus 130 communicates with the vehicle-mounted device of the passing vehicle 110 via the communication antenna 131 and receives ETC card information (billing destination information) attached to the vehicle-mounted device.
The roadside apparatus 130 transmits the received ETC card information to the toll collection apparatus 140. When the tow bar detection signal is output, the roadside wireless device 130 also transmits to the toll collection device 140 vehicle type information indicating that it is the towed vehicle 111.
The toll collection device 140 receives ETC card information, and collects a toll by performing billing processing based on the received ETC card information.

FIG. 9 is a flowchart showing the axle detection process of axle detection unit 220 in the first embodiment.
The axle detection process of the axle detection part 220 in Embodiment 1 is demonstrated based on FIG.

In S120, the axle detection unit 220 stands by until the vehicle detection start sensor 121 starts detecting the passing vehicle 110 based on the determination result of the vehicle detection unit 210 (S110 in FIG. 8).
“Begin detection” means shifting from a non-detected state to a detected state.
It progresses to S121 after S120.

In S121, the axle detection unit 220 initializes the axle number 292 and sets the axle number 292 to “0”.
It progresses to S122 after S121.

  In S122, the axle detection unit 220 waits until the axle detection sensor 123 starts to detect the axle (tire) of the passing vehicle 110.

  Whether the axle detection sensor 123 detects the axle of the passing vehicle 110 is determined as follows.

The axle detection unit 220 receives the scan data 291 output from the axle detection sensor 123.
The axle detection unit 220 compares the measured distance included in the input scan data 291 with a predetermined axle detection threshold. For example, the measurement angle and the axle detection threshold are associated with each measurement angle and stored in advance in the detection device storage unit 290. Then, the axle detection unit 220 compares the vehicle detection threshold and the measurement distance for each measurement angle.
The axle detection unit 220 determines that the axle detection sensor 123 detects the axle of the passing vehicle 110 when the scan data 291 includes a measurement distance (a predetermined number or more) that is shorter than the axle detection threshold. To do. However, the axle detection unit 220 calculates the height of the measurement point based on the height of the axle detection sensor 123, the measurement angle, and the measurement distance, and determines that the calculated measurement point height is lower than a predetermined vehicle body height threshold. You may add to judgment conditions. The vehicle body height threshold is a design value corresponding to the height of the lowest portion of the vehicle body of the passing vehicle 110. The vehicle body height threshold value is stored in the detection device storage unit 290 in advance.

  It progresses to S123 after S122.

In S123, the axle detection unit 220 outputs an axis detection signal (or data) to the roadside apparatus 130 until the axle detection sensor 123 finishes detecting the axle of the passing vehicle 110.
“End of detection” means shifting to a state in which detection is not performed after starting detection.
The axis detection signal is a signal indicating that the axle detection sensor 123 is detecting the axle of the passing vehicle 110.
After S123, the process proceeds to S124.

In S <b> 124, the axle detection unit 220 adds “1” to the number of axles 292.
It progresses to S125 after S124.

In S125, the axle detection unit 220 determines whether or not the vehicle detection end sensor 122 has detected the passing vehicle 110 based on the determination result of the vehicle detection unit 210 (S111 in FIG. 8).
When the vehicle detection end sensor 122 has detected the passing vehicle 110 (YES), the process proceeds to S126.
When the vehicle detection end sensor 122 has not detected the passing vehicle 110 (NO), the process returns to S122.

In S126, the axle detection unit 220 outputs an axle number detection signal (or data) indicating the axle number 292 to the roadside apparatus 130.
Due to S126, the axle detection process ends. However, the axle detection process (S120-S126) is repeatedly executed.

When the axle detection unit 220 outputs the number-of-axis detection signal, the roadside wireless device 130 receives the number-of-axis detection signal and outputs the number of axles 292 to the toll collection device 140 based on the received number-of-axis detection signal.
The toll collection device 140 determines a vehicle type based on the received ETC card information and the number of axles 292, and collects a toll according to the determined vehicle type. For example, vehicle type data in which ETC card information, the number of axles, and the vehicle type are associated with each other, and toll data in which the vehicle type is associated with the toll are stored in advance in the collection device storage unit of the toll collection device 140. The toll collection device 140 determines the vehicle type of the toll vehicle 110 corresponding to the number of axles based on the vehicle type data, and determines based on the toll fee data corresponding to the determined vehicle type.

FIG. 10 is a table showing the determination order of the forward / backward determination process of the forward / backward determination unit 230 in the first embodiment.
The forward / reverse determination process of the forward / reverse determination unit 230 in the first embodiment will be described with reference to FIG.

  The forward / reverse determination unit 230 determines whether the passing vehicle 110 has moved forward or backward based on the determination result of the vehicle detection unit 210 (S110 and S111 in FIG. 8).

When the vehicle detection start sensor 121 and the vehicle detection end sensor 122 detect the passing vehicle 110 in the order shown in FIG. 10A, the passing vehicle 110 is moving forward.
In this case, the forward / reverse determination unit 230 outputs a forward detection signal (or data) indicating that the passing vehicle 110 is moving forward to the roadside apparatus 130.

When the vehicle detection start sensor 121 and the vehicle detection end sensor 122 do not detect the passing vehicle 110 in the order shown in FIG. 10A, the passing vehicle 110 moves backward.
In this case, the forward / reverse determination unit 230 outputs a reverse detection signal indicating that the passing vehicle 110 is moving backward to the roadside apparatus 130 (or data).

For example, when (1) the vehicle detection start sensor 121 starts to detect the passing vehicle 110 and (2) the vehicle detection end sensor 122 starts to detect the passing vehicle 110, the passing vehicle 110 moves forward.
Further, (1) after the vehicle detection start sensor 121 starts to detect the passing vehicle 110, (2) before the vehicle detection end sensor 122 starts to detect the passing vehicle 110, (3) the vehicle detection start sensor 121 starts to detect the passing vehicle. When 110 is detected, the passing vehicle 110 is moving backward. Thereafter, when the passing vehicle 110 moves forward and passes through the detection area 101, the passing vehicle 110 is detected in the order of (1) (2) (3) (4).

For example, after (2) the vehicle detection end sensor 122 starts to detect the passing vehicle 110, and (3) when the vehicle detection start sensor 121 finishes detecting the passing vehicle 110, the passing vehicle 110 moves forward.
Further, (2) after the vehicle detection end sensor 122 starts to detect the passing vehicle 110, (3) before the vehicle detection start sensor 121 finishes detecting the passing vehicle 110, (4) the vehicle detection end sensor 122 becomes the passing vehicle. When 110 is detected, the passing vehicle 110 is moving backward. Thereafter, when the passing vehicle 110 moves forward and passes through the detection area 101, the passing vehicle 110 is detected in the order of (2) (3) (4).

The roadside apparatus 130 determines whether or not the passing vehicle 110 has passed through the detection area 101 based on the forward detection signal and the reverse detection signal.
The roadside apparatus 130 acquires the ETC card information from the passing vehicle 110 only once until the passing vehicle 110 passes through the detection area 101, and outputs the acquired card information to the toll collection device 140. This is because the toll is not collected twice for the passing vehicle 110.

  When the vehicle detection start sensor 121, the vehicle detection end sensor 122, and the upper vehicle detection sensor 124 detect the passing vehicle 110 in the order shown in FIG. 10B, the forward / reverse determination unit 230 moves the passing vehicle 110 forward. It may be determined that

FIG. 11 is a front view showing another example of the positional relationship of the laser sensors in the first embodiment.
Another example of the positional relationship of the laser sensor in the first embodiment will be described with reference to FIG.

The toll fee charging system 100 may include three laser sensors, a vehicle detection start sensor 121, a vehicle detection end sensor 122, and an axle detection sensor 123.
That is, the toll fee charging system 100 does not have to include the upper vehicle detection sensor 124 (see FIG. 3).

In this case, at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122 is installed at a position including the lower tow bar 112 and the upper tow bar 113 in the measurement region.
However, when it is not necessary to detect the upper tow bar 113, the vehicle detection start sensor 121 and the vehicle detection end sensor 122 may be installed at a position including the lower tow bar 112 in the measurement region.

The amount of reflection of the laser beam from the tire greatly depends on the incident angle of the laser beam. The closer the incident angle of the laser beam is to the vertical, the larger the amount of reflection.
In the embodiment, since the axle detection sensor 123 is provided at a position where the incident angle of the laser beam is nearly perpendicular to the tire, the tire (axle) can be detected correctly even during rain.

On the other hand, the reflectance of the laser beam from the vehicle body does not depend much on the incident angle of the laser beam.
Therefore, the vehicle detection start sensor 121 and the vehicle detection end sensor 122 are only required to emit laser light at a free angle with respect to the vehicle body.

FIG. 12 is a diagram illustrating an example of hardware resources of the vehicle detection device 200 according to the first embodiment.
In FIG. 12, the vehicle detection device 200 includes a CPU 901 (Central Processing Unit). The CPU 901 is connected to the ROM 903, the RAM 904, the communication board 905, the display device 911, the keyboard 912, the mouse 913, the drive device 914, and the magnetic disk device 920 via the bus 902, and controls these hardware devices. The drive device 914 is a device that reads and writes a storage medium such as an FD (Flexible Disk Drive), a CD (Compact Disc), and a DVD (Digital Versatile Disc).

  The communication board 905 is wired or wirelessly connected to a communication network such as a LAN (Local Area Network), the Internet, or a telephone line.

  The magnetic disk device 920 stores an OS 921 (operating system), a program group 922, and a file group 923.

  The program group 922 includes programs that execute the functions described as “units” in the embodiments. A program (for example, a vehicle detection program) is read and executed by the CPU 901. That is, the program causes the computer to function as “to part”, and causes the computer to execute the procedures and methods of “to part”.

  The file group 923 includes various data (input, output, determination result, calculation result, processing result, etc.) used in “˜part” described in the embodiment.

  In the embodiment, arrows included in the configuration diagrams and flowcharts mainly indicate input and output of data and signals.

  In the embodiment, what is described as “to part” may be “to circuit”, “to apparatus”, and “to device”, and “to step”, “to procedure”, and “to processing”. May be. That is, what is described as “to part” may be implemented by any of firmware, software, hardware, or a combination thereof.

The toll billing system 100 described in the first embodiment can provide the following effects.
Inexpensive parts can be used for the laser sensor instead of special parts such as a light receiving element and a light receiving optical system.
By detecting the axle with the axle detection sensor 123 based on the detection result of the vehicle detection start sensor 121, the axle of the vehicle traveling at high speed can be accurately detected.
By providing the axle detection sensor 123 so as to face the tire and close to the road surface, the detection accuracy of the axle is improved.
The upper vehicle detection sensor 124 can detect a tow bar having a diameter of 50 mm (upper tow bar 113). The upper vehicle detection sensor 124 need not have high performance.

The vehicle detection start sensor 121 and the vehicle detection end sensor 122 can detect the tow vehicle 111 having a tow bar (lower tow bar 112) having a diameter of 15 mm. That is, by taking a logical sum of the detection result of the vehicle detection start sensor 121 and the detection result of the vehicle detection end sensor 122, the tow vehicle 111, the lower tow bar 112, and the towed vehicle 119 can be detected as a unit. .
Even when the vehicle is traveling on the left or right side of the lane without traveling in the center of the lane, the vehicle can be detected by at least one of the vehicle detection start sensor 121 and the vehicle detection end sensor 122. .
By taking a logical sum of the detection result of the vehicle detection start sensor 121, the detection result of the vehicle detection end sensor 122, and the detection result of the axle detection sensor 123, the tow vehicle 111, the upper tow bar 113, and the towed vehicle 119 are integrated. Can be detected.
When the detection result of the vehicle detection start sensor 121 is used as a trigger, the axle detection sensor 123 starts detecting the axle, whereby the axle of a short nose vehicle traveling at high speed can be detected correctly.

Embodiment 2. FIG.
A mode of detecting the vehicle width, vehicle speed, and vehicle length of a passing vehicle will be described.
Hereinafter, items different from the first embodiment will be mainly described. Matters whose description is omitted are the same as those in the first embodiment.

FIG. 13 is a functional configuration diagram of the vehicle detection device 200 according to the second embodiment.
The functional configuration of the vehicle detection device 200 according to Embodiment 2 will be described with reference to FIG.

  The vehicle detection device 200 includes a vehicle width calculation unit 240, a vehicle speed calculation unit 250, and a vehicle length calculation unit 260 in addition to the configuration described in the first embodiment (see FIG. 7).

The vehicle width calculation unit 240 is based on the scanning data 291 (including the measurement distance) of the vehicle detection start sensor 121 and the scanning data 291 (including the measurement distance) of the vehicle detection end sensor 122, and the vehicle width 293 of the passing vehicle 110. Is calculated.
The vehicle width calculation unit 240 outputs a vehicle width detection signal indicating the calculated vehicle width 293 to the roadside apparatus 130.

For example, the vehicle width calculation unit 240 acquires the inter-sensor width distance 296 from the detection device storage unit 290. The inter-sensor width 296 is a distance between the vehicle detection start sensor 121 and the vehicle detection end sensor 122 and indicates a distance in the width direction of the road. The inter-sensor width distance 296 is stored in the detection device storage unit 290 in advance.
The vehicle width calculation unit 240 calculates a value obtained by subtracting the measurement distance of the vehicle detection start sensor 121 and the measurement distance of the vehicle detection end sensor 122 from the inter-sensor width distance 296 as the vehicle width 293 of the passing vehicle 110.
The measurement distance of the vehicle detection start sensor 121 is a measurement distance when the vehicle detection start sensor 121 detects the passing vehicle 110 (see S110 in FIG. 8). The measurement distance of the vehicle detection end sensor 122 is a measurement distance when the vehicle detection end sensor 122 detects the passing vehicle 110 (see S111 in FIG. 8).

The vehicle speed calculation unit 250 calculates the vehicle speed 294 of the passing vehicle 110 based on the scan data 291 (including the measurement time) of the vehicle detection start sensor 121 and the scan data 291 (including the measurement time) of the vehicle detection end sensor 122. To do.
The vehicle speed calculation unit 250 outputs a vehicle speed detection signal indicating the calculated vehicle speed 294 to the roadside apparatus 130.

For example, the vehicle speed calculation unit 250 acquires the inter-sensor travel distance 297 from the detection device storage unit 290. The inter-sensor travel distance 297 is a distance between the vehicle detection start sensor 121 and the vehicle detection end sensor 122 and indicates a distance in the travel direction of the travel vehicle 110. The inter-sensor travel distance 297 is stored in advance in the detection device storage unit 290.
The vehicle speed calculation unit 250 calculates the time difference between the measurement time when the vehicle detection start sensor 121 starts detecting the passing vehicle 110 and the measurement time when the vehicle detection end sensor 122 starts detecting the passing vehicle 110 as the passing time. .
The vehicle speed calculation unit 250 calculates a value obtained by dividing the inter-sensor travel distance 297 by the travel time as the vehicle speed 294 of the passing vehicle 110.

The vehicle length calculation unit 260 calculates the vehicle length 295 of the passing vehicle 110 based on the vehicle speed 294 and the scan data 291 (including the measurement time) of the vehicle detection start sensor 121 (or the vehicle detection end sensor 122).
The vehicle length calculation unit 260 outputs a vehicle length detection signal indicating the calculated vehicle length 295 to the roadside apparatus 130.

For example, the vehicle length calculation unit 260 calculates the time difference between the measurement time when the vehicle detection start sensor 121 starts detecting the passing vehicle 110 and the measurement time when the vehicle detection start sensor 121 finishes detecting the passing vehicle 110. Calculate as
The vehicle length calculator 260 calculates a value obtained by multiplying the vehicle speed 294 by the passage time as the vehicle length 295 of the passing vehicle 110.

  The toll collection device 140 obtains the vehicle width 293, the vehicle length 295, and the vehicle speed 294 via the roadside wireless device 130, and based on at least one of the vehicle width 293, the vehicle length 295, and the vehicle speed 294, The vehicle type is determined, and the toll according to the determined vehicle type is collected.

For example, vehicle type data in which the vehicle width range, the vehicle length range, and the vehicle type are associated with each other, and the toll data that associates the vehicle type with the toll are stored in advance in the collection device storage unit of the fee collection device 140. deep.
The toll collection device 140 determines the vehicle type corresponding to the vehicle width 293 and the vehicle length 295 of the passing vehicle 110 based on the vehicle type data.
The toll collection device 140 determines the toll corresponding to the determined vehicle type based on the toll data and collects the determined toll.

  However, the vehicle detection device 200 may include a vehicle type determination unit that determines the vehicle type of the passing vehicle 110 based on at least one of the vehicle width 293, the vehicle length 295, and the vehicle speed 294. In this case, the vehicle type data is stored in the detection device storage unit 290 in advance.

  100 toll charge system, 101 detection area, 102 F15 detection area, 103 F50 detection area, 110 toll vehicle, 111 towing vehicle, 112 lower tow bar, 113 upper tow bar, 119 towed vehicle, 121 vehicle detection start sensor, 121a Measurement area, 122 Vehicle detection end sensor, 122a Measurement area, 123 Axle detection sensor, 123a Measurement area, 124 Upper vehicle detection sensor, 124a Measurement area, 130 Roadside wireless device, 131 Communication antenna, 140 Toll collection device, 200 Vehicle detection device , 210 vehicle detection unit, 220 axle detection unit, 230 forward / reverse determination unit, 240 vehicle width calculation unit, 250 vehicle speed calculation unit, 260 vehicle length calculation unit, 290 detection device storage unit, 291 scan data, 292 number of axles, 293 vehicles Width, 294 Vehicle speed, 295 Length, 296 Distance between sensors, 297 Distance between sensors, 901 CPU, 902 bus, 903 ROM, 904 RAM, 905 Communication board, 911 Display device, 912 Keyboard, 913 Mouse, 914 Drive device, 920 Magnetic disk device, 921 OS, 922 program group, 923 file group.

Claims (8)

A vehicle detection sensor that is installed at a predetermined height beside the road, emits a laser beam from the road side toward the road surface, and receives the laser beam reflected by a passing vehicle passing through the road;
A vehicle detection system comprising: an axle detection sensor that is installed at a position lower than the vehicle detection sensor, emits radar light toward a road surface, and receives laser light reflected on a tire of the passing vehicle. The vehicle detection sensor receives laser light reflected on the passing vehicle as vehicle body reflected light,
The axle detection sensor receives laser light reflected on the tire of the passing vehicle as axle reflected light,
The vehicle detection system further includes:
While the vehicle detection sensor receives the vehicle body reflected light, the number of times the axle detection sensor starts receiving the axle reflected light and the axle detection sensor does not receive the axle reflected light is counted as the number of axles of the passing vehicle. The vehicle detection system according to claim 1, further comprising a detection device. The vehicle detection system includes a first vehicle detection sensor as the vehicle detection sensor,
The vehicle detection system further includes:
A laser beam is emitted toward a road surface that is installed at a position on the far side in the traveling direction of the passing vehicle with respect to the first vehicle detection sensor, and the laser beam reflected on the passing vehicle is received as a vehicle body reflected light. A second vehicle detection sensor
The axle detection sensor is located on the back side in the traveling direction of the passing vehicle with respect to the first vehicle detection sensor, and is located on the near side in the traveling direction of the passing vehicle with respect to the second vehicle detection sensor. Installed at the point where
The vehicle detection device counts the number of axles of the passing vehicle from when the first vehicle detection sensor starts to receive vehicle body reflected light until the second vehicle detection sensor stops receiving vehicle body reflected light. The vehicle detection system according to claim 2. The vehicle detection device counts the number of axles of the passing vehicle while at least one of the first vehicle detection sensor and the second vehicle detection sensor receives vehicle body reflected light. The vehicle detection system according to claim 3. The second vehicle detection sensor is installed on the side of the road opposite to the side of the road on which the first vehicle detection sensor is installed,
The axle detection sensor is installed on either the road side on the side where the first vehicle detection sensor is installed or on the road side on the side where the second vehicle detection sensor is installed. The vehicle detection system according to claim 3 or 4. The first vehicle detection sensor receives, as a tow bar reflected light, a laser beam reflected on the tow bar of the tow vehicle when a tow vehicle having a tow bar for towing the towed vehicle is passing,
The vehicle detection device determines whether or not the first vehicle detection sensor has received the tow bar reflected light, and determines whether or not the tow vehicle is passing based on the determination result. The vehicle detection system according to any one of claims 3 to 5. The first vehicle detection sensor receives a laser beam reflected as a tow bar reflected light on the tow bar of a tow vehicle having a tow bar at a lower portion of the vehicle body,
The vehicle detection system further includes:
The first vehicle detection sensor is installed at a position higher than the first vehicle detection sensor, emits laser light toward the road surface, and receives the laser light reflected on the tow bar of the tow vehicle having the tow bar at the top of the vehicle body as the tow bar reflected light. With three vehicle detection sensors,
The vehicle detection device determines that the tow vehicle is passing when at least one of the first vehicle detection sensor and the third vehicle detection sensor receives the tow bar reflected light. The vehicle detection system according to claim 6. A vehicle detection sensor installed at a predetermined height on the side of the road emits laser light from the side of the road toward the road surface, and receives laser light reflected by a passing vehicle passing through the road,
A vehicle detection method, wherein an axle detection sensor installed at a position lower than the vehicle detection sensor emits radar light toward a road surface and receives laser light reflected on a tire of the passing vehicle.

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