Axle Detection System

Abstract

To make it possible to reliably detect an axle of a traveling vehicle.SOLUTION: An axle detection device 1 is for detecting an axle of a vehicle A traveling on a road surface 11, which comprises: a laser projecting unit 3 and a laser receiving unit 4 that are arranged on the road surface 11 and detect a tire T of the vehicle A by projecting or receiving detection light in a lane width direction (±Y direction), wherein: the laser projecting unit 3 and the laser receiving unit 4 are arranged so as to project or receive the detection light at a position lower than the minimum ground clearance of the vehicle A; the laser projecting unit 3 projects light in one of the lane width directions (±Y directions); and the laser receiving unit 4 receives light from the other lane width direction (±Y directions).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This disclosure relates to Axle Detection System the following.

Background Art

[0002] At a general toll road, multiple driving lanes are installed at a tollgate, and tolls are collected from vehicles traveling in the driving lanes through a toll collection system such as an Electronic Toll Collection System (ETC (registered trademark), also referred to as an "automatic toll collection system"). The driving lanes at such a tollgate usually have a configuration separated by islands for each lane.

[0003] The toll collection system applied to a tollgate identifies the vehicle type classification (classification such as a light motor vehicle, a regular vehicle, a large vehicle, etc.) of the traveling vehicle in order to collect an appropriate toll from each traveling vehicle. As one means of discriminating the vehicle type classification of a traveling vehicle, it is known to measure the number of axles of the traveling vehicle. For example, the toll collection system described in Patent Document 1 installs a camera on the island of each driving lane to photograph the side of the traveling vehicle, and discriminates the vehicle type classification from the number of tires (= number of axles) of the traveling vehicle detected from the image.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The application of a multi-lane free-flow (MLFF) type toll collection system capable of collecting tolls from vehicles traveling on a road consisting of multiple lanes (for example, the main line of a toll road) is being promoted. When the MLFF type toll collection system is applied, the structure as a toll booth is eliminated from the toll road, and the island disappears, making it difficult to install a camera for photographing the side of the traveling vehicle. Further, if a camera is installed on the roadside of the main line, it is assumed that the tire will be hidden by another vehicle entering between the vehicle to be photographed and the camera, and correct detection will not be possible.

[0006] The present disclosure has been made in view of the above-described problems, and is capable of detecting the axles of a vehicle traveling on the road. Axle Detection System with the aim of providing.

Means for Solving the Problems

[0007] To achieve the above object, an axle detection system according to an aspect of the present disclosure includes an axle detection device for detecting the axles of a vehicle traveling on a road surface, and a vehicle detector installed at an upper position of a vehicle traveling on the road surface, and is an axle detection system comprising: the axle detection device is disposed on the road surface and includes an axle detection sensor that projects or receives detection light in the vehicle lane width direction to detect the tires of the vehicle, and the axle detection sensor is disposed so as to project or receive the detection light at a position lower than the lowest ground clearance of the vehicle body of the vehicle. It is provided so as to be installable on the road surface, and there is a housing body in which the axle detection sensor is housed inside. The axle detection sensor has a light projecting unit that projects detection light toward one side in the lane width direction, and a light receiving unit that receives the detection light from the other side in the lane width direction. The light projecting unit and the light receiving unit are housed in one housing body in a state of being arranged in series in the optical axis direction. The vehicle detector projects detection light toward the road surface, and based on the change in time from when the detection light is projected until the reflected light is received, detects the entry and exit of a vehicle traveling in the lower lane, and combines the detection period of the vehicle body by the vehicle detector and the number of times the tires are detected by the axle detection device to measure the number of axles of one vehicle.

[0009] Also, in the above Axle Detection System the housing body has a surface inclined with respect to the road surface.

[0012] In an axle detection system according to an aspect of the present disclosure, The axle detection sensoris arranged on both sides of the lane in the lane width direction .

Advantages of the Invention

[0014] According to the present invention Axle Detection System it is possible to reliably detect the axle of a vehicle in motion.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0016] Hereinafter, the Axle Detection System according to the embodiment of the present invention will be described with reference to the drawings. Such an embodiment shows one aspect of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention.

[0017] <First Embodiment> Hereinafter, with reference to FIGS. 1 to 3, the axle detection device according to the first embodiment will be described in detail.

[0018] (Overall Configuration of Axle Detection Device and Axle Detection System) FIG. 1 is a front view showing the overall configuration of the axle detection system. FIG. 2 is a first plan view of the overall configuration of the axle detection system as viewed from above. FIG. 3 is a perspective view showing the overall configuration of the axle detection device.

[0019] The axle detection device 1 according to the first embodiment shown in FIGS. 1 to 3 is applied to an MLFF type toll collection system. The axle detection device 1 is provided on the road surface 11 of a road consisting of a plurality of lanes (for example, the main line of a toll road), and detects the tire T (axle) of the vehicle A traveling on the road surface 11. The axle detection system 10 is composed of a plurality of axle detection devices 1 arranged for each lane L.

[0020] As shown in FIG. 1, the vehicle A using the toll road travels on one lane L in a road consisting of a plurality of lanes. In the following description, the direction in which the lane L extends (±X direction) is also referred to as the "lane direction", and the direction (±Y direction) that is horizontally orthogonal to the lane direction (±X direction) is also referred to as the "lane width direction". Also, the +X direction side in the lane direction (±X direction) is also referred to as the "downstream side". Also, the -X direction side in the lane direction (±X direction) is also referred to as the "upstream side". Also, the +Y direction side in the lane width direction (±Y direction) is also referred to as the "left side in the lane width direction" or the "left side in the traveling direction of the vehicle A". Also, the -Y direction side in the lane width direction (±Y direction) is also referred to as the "right side in the lane width direction" or the "right side in the traveling direction of the vehicle A". Also, the direction (±Z direction) orthogonal to the plane including the lane direction (±X direction) and the lane width direction (±Y direction) is also referred to as the "vertical direction" (+Z direction is the upper side and -Z direction is the lower side).

[0021] As shown in FIG. 3, the axle detection device 1 includes a housing 2 installed on the road surface 11, and a laser light projecting unit 3 (light projecting unit, axle detection sensor) and a laser light receiving unit 4 (light receiving unit, axle detection sensor) installed inside the housing 2. The laser light projecting unit 3 and the laser light receiving unit 4 are housed in the housing 2 so as to project or receive the laser light R (detection light) in the lane width direction (±Y direction).

[0022] The housing 2 has the shape of a frustum of a square pyramid and is trapezoidal when viewed from both the lane direction (±X direction) and the lane width direction (±Y direction). The housing 2 has an upper plate 21, a lower plate 22, a pair of inclined side plates 23, and a pair of inclined side plates 23a.

[0023] The upper plate 21 and the lower plate 22 are each rectangular, and the upper plate 21 is located at the center of the lower plate 22 in the lane width direction (±Y direction) when viewed from above.

[0024] The inclined side plate 23 forms the side surface on the lane direction side (±X direction side) of the housing 2. The inclined side plate 23 is formed in a trapezoidal shape. The inclined side plate 23 arranged on the downstream side (+X direction side) connects the side on the downstream side of the upper plate 21 to the side on the downstream side of the lower plate 22 with a surface inclined in the downstream direction (+X direction) and downward (-Z direction). Similarly, the inclined side plate 23 arranged on the upstream side (-X direction side) connects the side on the upstream side of the upper plate 21 to the side on the upstream side of the lower plate 22 with a surface inclined in the upstream direction (-X direction) and downward (-Z direction).

[0025] The inclined side plate 23a forms the side surface on the lane width direction (±Y direction) side of the housing 2 while having an opening 2a formed therein. The inclined side plate 23a arranged on the left side in the lane width direction (+Y direction side) connects the side on the left side in the lane width direction of the upper plate 21 to the side on the left side in the lane width direction of the lower plate 22 with a surface inclined in the left direction (+Y direction) and downward (-Z direction), and the opening 2a is formed so as to leave only the outer periphery of the surface. Similarly, the inclined side plate 23a arranged on the right side in the lane width direction (-Y direction side) connects the side on the right side in the lane width direction of the upper plate 21 to the side on the right side in the lane width direction of the lower plate 22 with a surface inclined in the right direction (-Y direction) and downward (-Z direction), and the opening 2a is formed so as to leave only the outer periphery of the surface.

[0026] Furthermore, the housing 2 has a vertical plate 24 provided so as to block the opening 2a in the vertical direction. A circular hole 24a is formed in the vertical plate 24, and the light projecting surface 3a of the laser light projecting unit 3 and the light receiving surface 4a of the laser light receiving unit 4 are installed so as to be fitted into the circular hole 24a. In this embodiment, a pair of laser light projecting units 3 are arranged on the vertical plate 24 on the right side (-Y direction side) in the lane width direction, and a pair of laser light receiving units 4 are arranged on the vertical plate 24 on the left side (+Y direction side) in the lane width direction. The pair of laser light projecting units 3 project laser light R in a direction parallel to the road surface 11 toward the right side (-Y direction side) in the lane width direction. The pair of laser light receiving units 4 receive the laser light R projected in a direction parallel to the road surface 11 from the left side (+Y direction side) in the lane width direction.

[0027] The height dimension of the housing 2 is set to be approximately the same as that of a well-known road stud, for example. Also, the vertical (±Z direction) positions of the laser light projecting unit 3 and the laser light receiving unit 4 are set to positions where the height of the laser light R to be projected or received is lower than the lowest ground clearance of the vehicle A.

[0028] Here, the lowest ground clearance is defined in "Notification No. 163, which specifies the details of the safety standards for road transport vehicles" (Ministry of Land, Infrastructure, Transport and Tourism notification) as 9 cm or more for the ground clearance of devices that are important for the structure and safety of motor vehicles, and 5 cm or more when an under cover or the like having a function to protect devices that are important for the structure and safety of motor vehicles is installed. Therefore, the laser light R is not blocked by the body of the vehicle A (including the under cover or the like), and the height of the laser light R blocked only by the tire T is desirably 9 cm or less, more desirably 5 cm or less, in terms of the lowest ground clearance.

[0029] In this embodiment, the laser light R is used as the detection light, but the detection light is not limited to the laser light R. The axle detection device 1 according to another embodiment may have an LED, and the light projected by the LED may be used as the detection light. However, in the case of the laser light R, since the diffusion is smaller than the light projected by the LED, it is suitable for adoption in the axle detection system 10 having the configuration as in this embodiment.

[0030] As shown in FIG. 2, the axle detection device 1 is arranged along the boundary line La that forms the lane L. The boundary line La is a lane boundary line and is indicated by a white broken line, a white solid line, or a yellow line on the road surface 11. As shown in FIG. 2, in this embodiment, five boundary lines La are provided, and the axle detection device 1 is provided on each boundary line La. These axle detection devices 1 are arranged at the same position in the lane direction (±X direction). That is, the laser light projecting unit 3 of the axle detection device 1 on the left side (+Y direction side) in the lane width direction and the laser light receiving unit 4 of the axle detection device 1 on the right side (-Y direction side) in the lane width direction are arranged to face each other in the lane width direction (±Y direction).

[0031] As shown in FIG. 1, the axle detection system 10 includes a vehicle detector 5 installed on a gantry G on the road surface. The vehicle detector 5 projects detection light toward the road surface 11 and detects the entry and exit of the vehicle A traveling in the lower lane L based on the change in the characteristics of the reflected light (for example, the time from when the detection light is projected to when the reflected light is received).

[0032] As shown in FIG. 2, the laser light projecting unit 3 of the axle detection device 1 arranged on the left side (+Y direction side) in the lane width direction of each lane L projects the laser light R, and the laser light receiving unit 4 of the axle detection device 1 on the opposite side (right side in the lane width direction (-Y direction side)) receives the laser light R. When the vehicle A passes through the lane L, the laser light R projected from the laser light projecting unit 3 is blocked by the tire T of the vehicle A, and the laser light receiving unit 4 no longer receives the laser light R. The axle detection system 10 detects the axle of the tire T by detecting that the light reception at the laser light receiving unit 4 has stopped (the transition from the light reception state to the non-light reception state). Furthermore, the axle detection system 10 can measure the number of axles of one vehicle A by combining the detection period of the vehicle body of the vehicle A by the vehicle detector 5 described above and the number of detections of the tire T by the axle detection device 1.

[0033] The axle detection device 1 of this embodiment is configured such that a laser light projecting unit 3 and a laser light receiving unit 4 are included inside one housing 2. Therefore, by arranging one axle detection device 1 on the boundary line La of the lane L, the laser light projecting unit 3 projects the laser light R toward the right side (-Y direction side) in the lane width direction, and at the same time, the laser light receiving unit 4 can receive the laser light R projected from the left side (+Y direction side) in the lane width direction.

[0034] (Function and Effect) According to the above-described axle detection device 1 and axle detection system 10, the axle detection sensor (laser light projecting unit 3, laser light receiving unit 4) can detect the tire T by projecting or receiving light in the lane width direction (±Y direction) with respect to the tire T of the traveling vehicle A. At this time, since the light projected or received from the axle detection sensor (laser light projecting unit 3, laser light receiving unit 4) passes through a position lower than the lowest ground clearance of the vehicle A, it is possible to project light from the side to all the tires T of the vehicle A. That is, the light is not blocked by the body of the vehicle A, and the light is blocked only by the tire T. Further, since the axle detection devices 1 and 1A can project light onto the tire T from a very short distance for detection, it is possible to prevent other traveling vehicles from entering between the axle detection devices 1 and 1A and the tire T of the vehicle A to be detected. Therefore, it is possible to surely and accurately detect the axle of the tire T of the vehicle A.

[0035] Further, according to the axle detection device 1 and axle detection system 10 according to this embodiment, a housing 2 that can be installed on the road surface 11 is provided, and the laser light projecting unit 3 and the laser light receiving unit 4 are housed and protected inside the housing 2. Therefore, it is possible to prevent problems such as the position of the axle detection sensor shifting when the traveling vehicle A runs over it, and it is possible to accurately detect the tire T. Furthermore, the housing 2 has the shape of a square frustum, and inclined surfaces are formed on the respective side surfaces in the lane direction (±X direction) and the lane width direction (±Y direction) with respect to the road surface. Thereby, it is possible to mitigate the impact and vibration generated when the traveling vehicle A runs over the axle detection device 1 (housing 2).

[0036] According to the axle detection device 1 and the axle detection system 10 according to the above-described embodiment, the axle of the traveling vehicle A can be reliably detected.

[0037] <Second Embodiment> Next, with reference to FIGS. 4 and 5, the axle detection device 1A and the axle detection system 10A according to the second embodiment will be described. Components having the same functions as those of the components of the first embodiment described above are denoted by the same reference numerals, and detailed descriptions thereof are omitted since the descriptions would be redundant.

[0038] (Overall Configuration of Axle Detection System) FIG. 4 is a second plan view of the overall configuration of the axle detection system as viewed from above. FIG. 5 is a perspective view showing the overall configuration of the axle detection device.

[0039] As shown in FIG. 4, the axle detection system 10A is a system in which the arrangement configuration of the laser light projecting unit 3 and the laser light receiving unit 4 housed in the housing 2 of the axle detection device 1A is changed from the first embodiment, and further, the reflecting unit 6 is used. That is, the axle detection system 10A is configured such that the axle detection device 1A and the reflecting unit 6 are alternately provided in the lane width direction (±Y direction) with respect to a plurality of boundary lines La located between the lanes L.

[0040] As shown in FIG. 5, in the axle detection device 1A, both the laser light projecting unit 3 and the laser light receiving unit 4 are arranged on one side (+Y direction side) and the other side (−Y direction side) in the lane width direction (±Y direction) by the housing 2. That is, the axle detection device 1A projects the laser light R from the laser light projecting unit 3 toward both sides (+Y direction side and −Y direction side) in the lane width direction (±Y direction), and the laser light receiving unit 4 receives the laser light R received from both sides (+Y direction side and −Y direction side) in the lane width direction (±Y direction).

[0041] The reflecting section 6 includes a reflector 6a having reflecting surfaces orthogonal to the road surface 11 on both sides in the vehicle lane width direction (±Y direction). The reflector 6a may be configured to impart recursiveness to the reflected light. The reflecting section 6 reflects the laser light R projected from the laser light projecting section 3 by the reflector 6a in a direction substantially opposite by 180 degrees toward the laser light receiving section 4 of the axle detection device 1A where the laser light projecting section 3 is disposed. The axle detection device 1A projects the laser light R from the laser light projecting section 3 toward the reflector 6a of the reflecting section 6, and receives the reflected light (laser light R) reflected by the reflector 6a at the laser light receiving section 4 provided on the same surface as the laser light projecting section 3 and facing the vehicle lane width direction (±Y direction).

[0042] In the axle detection system 10A of the second embodiment, similarly to the first embodiment described above, the vehicle detector 5 is installed on the gantry G. The vehicle detector 5 detects the entry and exit of the vehicle A traveling in the lower vehicle lane L.

[0043] The axle detection system 10A receives the laser light R projected from the laser light projecting section 3 of the axle detection device 1A by the reflectors 6a of the reflecting sections 6 adjacent in the vehicle lane width direction (±Y direction), and reflects it in a direction substantially opposite by 180°. The reflected reflected light (laser light R) is received by the laser light receiving section 4 provided in the same axle detection device 1A as the projected light projecting section 3A. When the vehicle A passes through the vehicle lane L, the laser light R projected from the laser light projecting section 3 is blocked by the tire T of the vehicle A, and the reflected light (laser light R) reflected by the reflector 6a of the reflecting section 6 disappears, and the laser light receiving section 4 stops receiving the laser light R. The axle detection system 10A detects the axle of the tire T by detecting that the light reception at the laser light receiving section 4 has stopped (the transition from the light reception state to the non-light reception state). Furthermore, the axle detection system 10A can measure the number of axles of one vehicle A by combining the detection period of the vehicle body of the vehicle A by the vehicle detector 5 described above and the number of detections of the tire T by the axle detection device 1A.

[0044] (Function and Effect) As described above, in the axle detection device 1A and the axle detection system 10A according to the second embodiment, a pair of combinations of the laser light projecting unit 3 and the laser light receiving unit 4 are arranged on one side (+Y direction side) and the other side (-Y direction side) in the lane width direction (±Y direction) of the same housing 2 and are integrally provided. Therefore, by arranging one axle detection device 1A on the boundary line La of the lane L, the laser light R is projected by the laser light projecting unit 3 toward both sides in the lane width direction (±Y direction) (+Y direction side and -Y direction side), and the laser light R reflected by the reflecting unit 6 can be received by the laser light receiving unit 4 from both sides in the lane width direction (±Y direction) (+Y direction side and -Y direction side).

[0045] As described above, since the axle detection system 10A according to the second embodiment has a configuration using the reflecting unit 6, the number of installed axle detection devices 1A provided on the boundary lines La of a plurality of lanes L can be reduced to half the quantity. Therefore, the power supply and signal wiring connected to the laser light projecting unit 3 and the laser light receiving unit 4 of the axle detection device 1A can be reduced.

[0046] As described above, each embodiment of the axle detection device and the axle detection system according to the present invention has been described. However, the present disclosure is not limited to the above embodiments and can be appropriately changed without departing from the gist thereof.

[0047] For example, the shape and size of the housing 2 in the axle detection devices 1 and 1A are not limited to the above embodiments. That is, the axle detection devices 1 and 1A may have any shape and size as long as the axle detection sensors housed therein are arranged so as to project or receive light in the lane width direction and in a direction parallel to the road surface 11.

[0048] As described above, although some embodiments according to the present disclosure have been described, all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and the equivalent scope thereof.

[0049] <Supplementary Note> Those described in the above embodiments Axle Detection System are understood as follows, for example.

[0050] (1) According to the first aspect, the axle detection devices 1 and 1A are axle detection devices for detecting the axles of the vehicle A traveling on the road surface 11. The axle detection devices are arranged on the road surface 11 and include axle detection sensors (laser light projecting unit 3, laser light receiving unit 4) that project or receive light in the vehicle width direction (±Y direction) to detect the tires T of the vehicle A. The axle detection sensors (laser light projecting unit 3, laser light receiving unit 4) are arranged to project or receive light at a position lower than the lowest ground clearance of the vehicle A.

[0051] By doing so, the axle detection sensors (laser light projecting unit 3, laser light receiving unit 4) can detect the tires T by projecting or receiving light in the vehicle width direction (±Y direction) with respect to the tires T of the traveling vehicle A. At this time, since the light projected or received from the axle detection sensors (laser light projecting unit 3, laser light receiving unit 4) passes through a position lower than the lowest ground clearance of the vehicle A, it is possible to project light from the side onto all the tires T of the vehicle A. That is, the light is not blocked by the body of the vehicle A, and is blocked only by the tires T. Furthermore, since the axle detection devices 1 and 1A can project light onto the tires T for detection from a very short distance, it is possible to prevent other vehicles from entering between the axle detection devices 1 and 1A and the tires T of the vehicle A to be detected. Therefore, the axles of the tires T of the vehicle A can be detected.

[0052] (2) According to the second aspect, there is provided a container 2 that can be installed on the road surface 11, and an axle detection sensor (laser light projecting unit 3, laser light receiving unit 4) is accommodated inside the container 2.

[0053] By doing so, since it is protected by the axle detection sensor (laser light projecting unit 3, laser light receiving unit 4), it is possible to prevent problems such as the position of the axle detection sensor shifting when the traveling vehicle A rides on it, and it is possible to accurately detect the tire T.

[0054] (3) According to the third aspect, the container 2 has a surface that is inclined with respect to the road surface.

[0055] By doing so, it is possible to alleviate the impact and vibration that occur when the traveling vehicle A rides on the axle detection device 1 (container 2).

[0056] (4) According to the fourth aspect, the axle detection sensor includes a laser light projecting unit 3 that projects detection light toward one side in the vehicle lane width direction (±Y direction), and a laser light receiving unit 4 that receives the detection light from the other side in the vehicle lane width direction (±Y direction).

[0057] By doing so, when the vehicle A has not passed, the laser light R projected from the pair of laser light projecting units 3 of one axle detection device 1 is received by the pair of laser light receiving units 4 of the other adjacent axle detection device 1 in the vehicle lane width direction (±Y direction). When the vehicle A passes through the vehicle lane L, the laser light R projected from the laser light projecting unit 3 is blocked by the tire T of the vehicle A, and the laser light receiving unit 4 no longer receives the laser light R. By detecting that the reception of the laser light by the laser light receiving unit 4 has been interrupted, it is possible to detect the tire T (axle). Also, in this case, the laser light projecting unit 3 and the laser light receiving unit 4 are integrally provided in one axle detection device 1. Therefore, by arranging the axle detection devices 1 on both sides of the vehicle lane L, the laser light R can be projected in one direction (+Y direction side) in the vehicle lane width direction (±Y direction) by the laser light projecting unit 3, and the laser light R projected from the other side (-Y direction side) can be received by the laser light receiving unit 4.

[0058] (5) According to the fifth aspect, the axle detection sensor includes a laser light projecting unit 3 that projects detection light toward one of the vehicle width directions (±Y directions), and a laser light receiving unit 4 that receives the reflected light of the detection light from one of the vehicle width directions (±Y directions).

[0059] By doing so, the detection direction using the reflecting portion 6 can be adopted. For example, when the vehicle A has not passed, the laser light R projected from the laser light projecting unit 3 of the axle detection device 1A is reflected by the adjacent reflecting portions 6 in the vehicle width direction (±Y directions) toward the opposite side. This reflected reflected light (laser light R) is received by the laser light receiving unit 4 provided in the same axle detection device 1A as the light projecting unit 3A that projected the light. When the vehicle A passes through the lane L, the laser light R projected from the laser light projecting unit 3 is blocked by the tire T of the vehicle A, the reflected light (laser light R) reflected by the reflecting portion 6 disappears, and the reflected light (laser light R) is no longer received by the laser light receiving unit 4. By detecting that the reception by this laser light receiving unit 4 has been interrupted, the tire T (axle) can be detected.

[0060] (6) According to the sixth aspect, there is provided an axle detection system for detecting the axles of a vehicle A traveling on a road surface 11, the system including an axle detection sensor that is disposed on the road surface 11 and detects the tire T of the vehicle A by projecting or receiving detection light (laser light R) in the vehicle width direction (±Y directions). The axle detection sensor is disposed so as to project or receive detection light at a position lower than the lowest ground clearance of the vehicle A, and the axle detection sensor is disposed on both sides of the lane L in the vehicle width direction (±Y directions). One of the axle detection sensors is provided with a laser light receiving unit 4, and the other axle detection sensor is provided with a laser light receiving unit 4 that receives the light projected from the laser light projecting unit 3.

[0061] In this way, when the vehicle A has not passed, the laser light R projected from the laser light projecting unit 3 of one axle detection device 1 is received by the laser light receiving unit 4 of the other adjacent axle detection device 1 in the lane width direction (±Y direction). When the vehicle A passes through the lane L, the laser light R projected from the laser light projecting unit 3 is blocked by the tire T of the vehicle A, and the laser light receiving unit 4 no longer receives the laser light R. By detecting that the reception by the laser light receiving unit 4 has been interrupted, the tire T (axle) can be detected. Also, in this case, the laser light projecting unit 3 and the laser light receiving unit 4 are integrally provided in one axle detection device 1. Therefore, by arranging the axle detection devices 1 on both sides of the lane L, the laser light R can be projected in one direction (+Y direction side) in the lane width direction (±Y direction) by the laser light projecting unit 3, and the laser light R projected from the other side (-Y direction side) can be received by the laser light receiving unit 4.

[0062] (7) According to the seventh aspect, there is provided an axle detection system for detecting an axle of a vehicle A traveling on a road surface 11, the system including: an axle detection sensor disposed on one road surface 11 in the lane width direction (±Y direction) of a lane L, the axle detection sensor having a laser light projecting unit 3 that projects detection light in one direction in the lane width direction (±Y direction) and a laser light receiving unit 4 that receives detection light from one direction in the lane width direction (±Y direction); and a reflection unit 6 provided at a position facing the axle detection sensor on one side in the lane width direction (±Y direction). The axle detection sensor is arranged to project and receive detection light at a position lower than the lowest ground clearance of the vehicle A, the reflection unit 6 reflects the light projected from the laser light projecting unit 3, and the laser light receiving unit 4 receives the light reflected by the reflection unit 6.

[0063] By doing so, when the vehicle A has not passed, the laser light R projected from the laser light projecting unit 3 of the axle detection device 1A is reflected by the adjacent reflection units 6 in the vehicle width direction (±Y direction) toward the opposite side. This reflected light (laser light R) is received by the laser light receiving unit 4 provided in the same axle detection device 1A as the light projecting unit 3A from which it is projected. When the vehicle A passes through the lane L, the laser light R projected from the laser light projecting unit 3 is blocked by the tire T of the vehicle A, the reflected light (laser light R) reflected by the reflection unit 6 disappears, and the laser light receiving unit 4 no longer receives the reflected light (laser light R). By detecting that the reception by the laser light receiving unit 4 has been interrupted, the tire T (axle) can be detected. Also, in this case, a pair of combinations of the laser light projecting unit 3 and the laser light receiving unit 4 are arranged on one side (+Y direction side) and the other side (-Y direction side) in the vehicle width direction (±Y direction) of the same axle detection device 1A and are integrally provided. Therefore, by arranging one axle detection device 1A on the boundary line La of the lane L, the laser light R is projected by the laser light projecting unit 3 toward both sides (+Y direction side and -Y direction side) in the vehicle width direction (±Y direction), and the laser light R reflected by the reflection unit 6 can be received by the laser light receiving unit 4 from both sides (+Y direction side and -Y direction side) in the vehicle width direction (±Y direction).

Explanation of Reference Numerals

[0064] 1, 1A Axle detection device 2 Housing 3 Laser light projecting unit (light projecting unit, axle detection sensor) 4 Laser light receiving unit (light receiving unit, axle detection sensor) 5 Vehicle detector 6 Reflection unit 6a Reflector 10, 10A Axle detection system A Vehicle L Lane La Boundary line T Tire

Claims

1. An axle detection system comprising an axle detection device for detecting an axle of a vehicle traveling on a road surface, and a vehicle detector installed at an upper position above a vehicle traveling on the road surface, wherein the axle detection device is disposed on the road surface and includes an axle detection sensor that projects or receives detection light in the lane width direction to detect a tire of the vehicle, the axle detection sensor is arranged to project or receive the detection light at a position lower than the lowest ground clearance of the vehicle body of the vehicle, provided so as to be installable on the road surface, and provided with a housing in which the axle detection sensor is housed inside, the axle detection sensor has a light projecting unit that projects detection light toward one side in the lane width direction and a light receiving unit that receives detection light from the other side in the lane width direction, the light projecting unit and the light receiving unit are housed in one housing in a state of being arranged in series in the optical axis direction, the vehicle detector projects detection light toward the road surface, and based on a change in time from when the detection light is projected until the reflected light is received, detects the entry and exit of a vehicle traveling in the lower lane, and measures the number of axles of one vehicle by combining the detection period of the vehicle body by the vehicle detector and the number of times the tire is detected by the axle detection device. An axle detection system.

2. The housing has a surface inclined with respect to the road surface. The axle detection system according to claim 1.

3. The axle detection system according to claim 1 or 2, wherein the axle detection sensors are arranged on both sides of the lane in the lane width direction.

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