Vehicle width measurement device, vehicle type discrimination device, vehicle type discrimination system, vehicle width measurement method and program

Abstract

To provide a vehicle width measurement device capable of measuring the width of a vehicle with a simple configuration.SOLUTION: A vehicle width measurement device 10 comprises: an acquisition unit 1000 for acquiring scanning information from a laser scanner that is provided only on one of road sides and that can scan a laser beam projected from a projection unit along a plane intersection a vehicle lane direction; and a vehicle width measurement unit 1002 that measures a width of a vehicle traveling a vehicle lane on the basis of the acquired scanning information.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a vehicle width measurement device, a vehicle type discrimination device, a vehicle type discrimination system, a vehicle width measurement method, and a program. [Background technology]

[0002] On toll roads where toll fees are set according to vehicle type classification (such as "ordinary vehicles" and "large vehicles"), consideration is being given to measuring the width of vehicles traveling at toll booths using sensors or other devices and then using the results of this width measurement to determine the vehicle type classification.

[0003] Reflection-type sensors are known that can measure the distance to an object (vehicle body) by emitting laser light and measuring the time it takes for the reflected light to return or the phase shift of the reflected light. When using such a reflection-type sensor to measure the width of a moving vehicle, the following two configurations are typically considered. (1) A reflective sensor is provided above the vehicle, and a laser beam is emitted downward (toward the vehicle ceiling) from the reflective sensor while scanning the laser beam in the lane width direction. (2) A reflective sensor is installed on both sides of the road, and laser light is emitted from the two reflective sensors so that the vehicle is sandwiched between them. The vehicle width is calculated from the measurement results of the distance between each reflective sensor and the side of the vehicle.

[0004] As a technology related to the present disclosure, for example, Patent Document 1 discloses a method of irradiating a laser pulse from above the vehicle in a cross-sectional direction across the aisle at a predetermined period and determining the vehicle type from the height and shape of the ceiling surface of the driver's seat. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-319290 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of (1), the length equivalent to the vehicle width can be measured from the scan information obtained by scanning the top surface of the moving vehicle in the width direction. However, in this configuration, a large support member such as a gantry is required to place the reflective sensor above the vehicle.

[0007] In the case of (2), the distance to the side of the vehicle body of each of the reflective sensors installed on both sides is measured, so the vehicle width can be measured (calculated) by subtracting the measurement result of each distance from the interval between the reflective sensors (known information). However, in this configuration, it is necessary to install reflective sensors on both sides of the lane, which requires the effort of burying cables in the lane and the effort of preparing two reflective sensors, resulting in problems such as increased costs and longer construction time. In addition, in the case of (2), it is necessary to secure space to install sensors on both sides of the lane, which occupies the area of ​​the island. In addition, it cannot be applied to side lanes where it is physically impossible to install sensors on both sides of the lane.

[0008] An object of the present disclosure is to provide a vehicle width measurement device, a vehicle type discrimination device, a vehicle type discrimination system, a vehicle width measurement method, and a program that are capable of measuring the width of a vehicle with a simple configuration. [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a vehicle width measuring device is provided with: a laser scanner provided on only one side of a road; the laser scanner is capable of scanning laser light projected from a light-projecting unit along a plane intersecting a lane direction; and the vehicle width measuring unit measures the vehicle width of a vehicle traveling in a lane based on the acquired scan information.

[0010] According to one aspect of the present disclosure, a vehicle width measurement method includes a step of acquiring scan information including distance measurement results for each scan angle from a laser scanner provided on only one side of a road and capable of scanning laser light projected from a light-projecting unit along a plane intersecting a lane direction, and a step of measuring the width of a vehicle traveling in the lane based on the acquired scan information.

[0011] According to one aspect of the present disclosure, the program causes a computer of a vehicle width measuring device to execute the steps of acquiring scan information including distance measurement results for each scan angle from a laser scanner provided on only one side of the road and capable of scanning laser light projected from a light-projecting unit along a plane intersecting the lane direction, and measuring the width of a vehicle traveling in the lane based on the acquired scan information. Effect of the Invention

[0012] According to each of the above-described aspects, the vehicle width can be measured with a simple configuration. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram showing an overall configuration of a vehicle type discrimination system according to a first embodiment. [Diagram 2] 1 is a diagram showing a functional configuration of a vehicle type discrimination device according to a first embodiment. [Diagram 3] 3 is a diagram showing a process flow of the vehicle type discrimination device according to the first embodiment; FIG. [Figure 4] FIG. 3 is a first explanatory diagram of a vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. [Diagram 5] FIG. 6 is a second explanatory diagram of the process of vehicle width measurement in the vehicle type discrimination device according to the first embodiment. [Figure 6] FIG. 7 is a third explanatory diagram of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. [Figure 7] FIG. 11 is a fourth explanatory diagram of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. [Figure 8]FIG. 11 is a fifth explanatory diagram of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. [Figure 9] FIG. 6 is a sixth explanatory diagram of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] <First embodiment> Hereinafter, a vehicle type discrimination system according to a first embodiment will be described with reference to FIGS.

[0015] (Overall configuration of vehicle type discrimination system) Fig. 1 is a diagram showing the overall configuration of a vehicle type discrimination system according to the first embodiment. In the following description, the extension direction of the lane R (±X direction in Fig. 1) is also referred to as the "lane direction", the width direction of the lane R (±Y direction in Fig. 1) is also referred to as the "lane width direction", and the direction perpendicular to the road surface of the lane R (XY plane in Fig. 1) (±Z direction) is also referred to as the "height direction".

[0016] A vehicle type discrimination system 1 shown in FIG. 1 is used at a tollgate (entrance or exit) of a toll road for the purpose of discriminating the vehicle type category of each traveling vehicle in order to determine the toll to be collected from the vehicle.

[0017] Lane R is a driving lane of the toll gate, where vehicle A, which is the subject of toll collection, travels. On both sides of lane R, islands I are provided as areas one level higher than the road surface of lane R.

[0018] As shown in FIG. 1, the vehicle type discrimination system 1 includes a vehicle type discrimination device 10 (vehicle width measurement device) and a laser scanner 11.

[0019] The vehicle type discrimination device 10 has a function as a vehicle width measuring device that acquires scan information from the laser scanner 11 and measures the vehicle width of the vehicle A traveling on the lane R based on the scan information. Here, the scan information is information including the distance measurement result for each scanning angle of the laser light (the scan information will be described in detail later). The vehicle type discrimination device 10 discriminates the vehicle type classification of the vehicle A based on the measurement result of the vehicle width. In this embodiment, for simplification, the vehicle type discrimination device 10 is described as discriminating the vehicle type classification of the vehicle A only from the measurement result of the vehicle width, but is not limited to this in other embodiments. For example, the vehicle type discrimination device 10 according to other embodiments may be capable of discriminating the vehicle type classification defined more finely by acquiring license plate information (classification number) and the number of axles in addition to the measurement result of the vehicle width. In this case, the vehicle type discrimination system 1 is assumed to include, in addition to the laser scanner 11, a license plate recognition device for reading the license plate information of the vehicle A, a tread (tire detection sensor) for measuring the number of axles of the vehicle A, and the like.

[0020] Next, the configuration and functions of the laser scanner 11 will be described in detail with reference to FIG.

[0021] As shown in Fig. 1, the laser scanner 11 is installed on an island I on the road side of lane R. The laser scanner 11 according to this embodiment is installed on the island I on the right side (-Y direction side) of the traveling direction of vehicle A, but in other embodiments, it may be installed on the left side (+Y direction side) of the traveling direction. Note that, in order to ensure safe traveling of the vehicle on lane R, the laser scanner 11 is installed so that the distance m from the end face facing the lane side (end face on the +Y direction side) to lane R is 250 mm or more.

[0022] The laser scanner 11 is a reflective sensor and has a light-projecting unit 11a that projects laser light L. The light-projecting unit 11a is installed at a predetermined height, "sensor height Hs," based on the road surface of the lane R. The sensor height Hs is appropriately determined based on its relationship with the body shape of a traveling vehicle. The sensor height Hs will be described in detail later.

[0023] The light-projecting unit 11a projects laser light L from an installation position on the island I toward the lane R. The projected laser light L is reflected by the surface of the object to be irradiated (the body of the vehicle A), and a part of it returns as reflected light. The reflected light is received and detected by a light-receiving unit (not shown) provided at the same position as the light-projecting unit 11a. The laser scanner 11 measures the distance from its own position to the reflection position (i.e., the surface of the object to be irradiated) based on the time difference between when the laser light L is projected and when the reflected light is received, or the phase difference between the laser light L and the reflected light.

[0024] The laser scanner 11 is a so-called two-dimensional (2D) laser scanner. That is, the laser scanner 11 continuously projects the laser light L in a plurality of directions while changing (rotating) the projection direction (angle θ) of the laser light L by a small angle each time around an axis in the lane direction (±X direction). By this operation, the light projection unit 11a scans the laser light L along a plane (YZ plane in FIG. 1) intersecting with the lane R. The laser scanner 11 repeats one scan at a constant cycle (for example, a cycle of several tens to several hundreds of msec).

[0025] The laser scanner 11 calculates an observation point (coordinates (Y, Z)) indicating the reflection position on the scanning surface (YZ plane) of the laser light L based on the projection direction (angle θ) of the laser light L and the distance to the reflection position in that direction. In this way, the laser scanner 11 acquires scan information (point cloud data) consisting of a set of observation points (coordinates (Y, Z)) on the YZ plane for each of the laser lights L projected in each direction in one scan.

[0026] In this embodiment, the origin O of the laser scanner 11 is a point that is the position of the road surface of the lane R in the height direction (Z-axis) and also the position of the light-projecting unit 11a in the lane width direction (Y-axis), as shown in Figure 1.

[0027] Moreover, the laser scanner 11 predefines a predetermined effective range Q based on the origin O, and the scan information includes only the observation points detected within this effective range Q. In this way, it is possible to exclude information that is unnecessary for measuring the vehicle width of the vehicle A traveling in the lane R (for example, observation points due to vehicles or structures traveling in a lane adjacent to the lane R).

[0028] (Functional configuration of vehicle type discrimination device) FIG. 2 is a diagram showing a functional configuration of the vehicle type discrimination device according to the first embodiment. As shown in FIG. 2, the vehicle type discrimination device 10 includes a CPU 100, a communication interface 101, and a recording medium .

[0029] The CPU 100 is a processor that controls the overall operation of the vehicle type discrimination device 10. The CPU 100 performs various functions by operating according to a program prepared in advance. The functions of the CPU 100 will be described later.

[0030] The communication interface 101 is a connection interface with the laser scanner 11 (FIG. 1).

[0031] The recording medium 102 is a so-called auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD). In addition to a program that operates the CPU 100, the recording medium 102 records, for example, feature quantities and determination thresholds required for the process of determining the vehicle type category from the measurement result of the vehicle width.

[0032] The CPU 100 according to this embodiment operates according to a program to fulfill the functions of an acquisition unit 1000, a detection unit 1001, a vehicle width measurement unit 1002, and a vehicle type discrimination unit 1003.

[0033] The acquisition unit 1000 receives and acquires scan information (point cloud data) output from the laser scanner 11 from time to time. The scan information acquired by the acquisition unit 1000 is sequentially stored in a memory (a so-called main storage device, not shown) provided in the vehicle type discrimination device 10 while being accompanied by time information indicating the acquisition time.

[0034] The detection unit 1001 detects the entry and exit of the vehicle A based on the characteristics of the scan information acquired through the laser scanner 11 and the acquisition unit 1000.

[0035] The vehicle width measurement unit 1002 measures the width of the vehicle A from the scan information acquired through the laser scanner 11 and the acquisition unit 1000.

[0036] The vehicle type discrimination unit 1003 discriminates the vehicle type category of the vehicle A based on the vehicle width measurement result by the vehicle width measurement unit 1002.

[0037] Of the above-mentioned functional components, the acquisition unit 1000, the detection unit 1001, and the vehicle width measurement unit 1002 are functional components that serve as a vehicle width measurement device included in the vehicle type discrimination device 10.

[0038] (Processing flow of vehicle type discrimination device) FIG. 3 is a diagram showing a process flow of the vehicle type discrimination device according to the first embodiment. The process flow shown in Fig. 3 is constantly and repeatedly executed by the vehicle type discrimination device 10 (vehicle width measurement device). During this process flow, the laser scanner 11 constantly and repeatedly performs scanning with the laser light L at a constant period (for example, a period of several tens to several hundreds of msec), and sequentially transmits the scan information acquired by each scan to the vehicle type discrimination device 10 (vehicle width measurement device) at the same period.

[0039] First, the detection unit 1001 of the vehicle type discrimination device 10 (vehicle width measurement device) detects the entry of the vehicle A based on the scan information received at regular intervals from the acquisition unit 1000 (step S1). Here, only the contour of the road surface of lane R is read from the scan information acquired while no vehicle is present in lane R. In this case, the vehicle type discrimination device 10 determines that no vehicle is present in lane R and ends the process without performing any special process. On the other hand, when a vehicle enters lane R, the scan information reads the outline of an object (i.e., the body of vehicle A) different from the road surface of lane R. When the outline of an object different from the road surface is read for the first time from a state in which only the outline of the road surface of lane R has been read, the detection unit 1001 determines that a new vehicle A has entered.

[0040] Even after detecting the entry of vehicle A (step S1), the acquisition unit 1000 of the vehicle type discrimination device 10 (vehicle width measurement device) continues to receive and acquire scan information obtained at regular intervals from the laser scanner 11 from time to time. At this time, the acquisition unit 1000 associates all scan information acquired from the detection of the entry of vehicle A (step S1) until the detection of its exit (step S3 described below) as scan information for vehicle A, and records and accumulates it in memory (step S2).

[0041] The detection unit 1001 detects the exit of the vehicle A based on the scan information acquired at regular intervals from the acquisition unit 1000 (step S3). Specifically, the detection unit 1001 determines that the vehicle A has exited when the state returns from a state in which the outline of an object other than the road surface was read (a state in which the presence of the vehicle A was detected) to a state in which only the outline of the road surface of the lane R is read.

[0042] Next, the vehicle width measurement unit 1002 of the vehicle type discrimination device 10 (vehicle width measurement device) measures the vehicle width of the vehicle A (step S4) based on all the scan information acquired from the detection of the entry of the vehicle A (step S1) until the detection of its exit (step S3 described above). The details of the process of step S4 will be described later.

[0043] Next, the vehicle type discrimination unit 1003 of the vehicle type discrimination device 10 discriminates the vehicle type category of the vehicle A based on the vehicle width measured in step S4. As the simplest example, the vehicle type discrimination unit 1003 compares the vehicle width measured in step S4 with a predetermined judgment threshold, and judges the vehicle A to be a "standard vehicle" if the vehicle width is less than the judgment threshold, and a "large vehicle" if the vehicle width is equal to or greater than the judgment threshold. As described above, the vehicle type discrimination unit 1003 may perform discrimination processing for more finely classified vehicle types in combination with other information (such as license plate information and number of axles). After the vehicle type determination process for one vehicle is completed, the series of scan information temporarily recorded in step S2 may be erased in preparation for the following vehicle.

[0044] (Vehicle width measurement processing) 4 to 6 are explanatory diagrams of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. The vehicle width measurement process (step S4 in FIG. 3) performed by the vehicle type discrimination device 10 will be described in detail below with reference to FIGS.

[0045] FIG. 4 shows the state of irradiation of the laser light L when vehicle A, a freight vehicle classified as a "large vehicle," arrives.

[0046] As shown in Fig. 4, the height (sensor height Hs) of the light-projecting unit 11a of the laser scanner 11 is installed at a position lower than the height Hwu of the upper end of a side window of a typical freight car. With this configuration, as shown in Fig. 4, of the laser light L projected in each direction from the light-projecting unit 11a, the laser light L projected toward the side window W of the vehicle A, which is a freight car, passes through the side window W and is irradiated onto the interior ceiling C. As a result of the interior ceiling C of the cabin (driver's cab) of the vehicle A being included in the scanning plane, the scan information includes information corresponding to the vehicle width of the vehicle A.

[0047] Here, the "side window top height Hwu of a general freight car" is set to 2.5 m (meters) in this embodiment. That is, the light projecting unit 11a of the laser scanner 11 according to this embodiment is installed at a position lower than 2.5 m (sensor height Hs<2.5 m).

[0048] Fig. 5 is an example of scan information SD obtained from the scanning result of the laser light L shown in Fig. 4. As shown in Fig. 5, the scan information SD consists of a set of observation points p observed by each of the laser lights L projected in each direction during the scanning process.

[0049] FIG. 6 shows all the scan information SD acquired during the passage of vehicle A (from the time of detection of entry to the time of detection of exit) arranged in time history. In FIG. 6, scan information SD1 is scan information acquired when the entry of vehicle A is detected, and is scan information in the vicinity of the front end of the body of vehicle A. Scan information SD2 is scan information acquired immediately before the exit of vehicle A is detected, and is scan information in the vicinity of the rear end of the body of vehicle A. Scan information SD3 is scan information in an area of ​​the body of vehicle A where a side window W (FIG. 4) is present. Thus, scan information SD3 includes an observation point p having a larger value on the +Y direction side compared to other scan information. This is because, as shown in FIG. 4, the laser light L projected toward the side window W passes through the side window W and reaches the interior ceiling C behind it.

[0050] The vehicle width measurement unit 1002 extracts the position (y2) of the observation point p2 that is farthest from the position of the light projector 11a (origin O) and the position (y1) of the observation point p1 that is closest in the lane width direction (±Y direction) from the entire series of scan information SD acquired as shown in Fig. 6. The vehicle width measurement unit 1002 then calculates the difference (Δy=y2-y1) between the position (y2) of the observation point p2 and the position (y1) of the observation point p1. The vehicle width measurement unit 1002 regards this calculation result (Δy) as the vehicle width of vehicle A.

[0051] (Processing of various vehicles while they are running) 7 to 9 are explanatory diagrams of the vehicle width measurement process of the vehicle type discrimination device according to the first embodiment. 7 to 9 each show a state in which the laser light L is irradiated when the vehicle A is a vehicle other than a freight car.

[0052] (If vehicle A is a passenger car) FIG. 7 shows the state of irradiation of the laser light L when a passenger car classified as a "standard car" arrives as vehicle A.

[0053] As shown in Fig. 7, the height (sensor height Hs) of the light projecting unit 11a of the laser scanner 11 is installed so as to be lower than the height Hwu' of the top edge of a side window of a typical passenger vehicle. With this configuration, as shown in Fig. 7, of the laser light L projected in each direction from the light projecting unit 11a, the laser light L projected toward the side window W of the vehicle A, which is a passenger vehicle, passes through the side window W and is irradiated onto the interior ceiling C. In this way, as in the case where the vehicle A is a freight vehicle (see Fig. 4), the interior ceiling C of the vehicle A, which is a passenger vehicle, is included in the scanning plane, and the scan information includes information corresponding to the vehicle width of the vehicle A.

[0054] Here, in this embodiment, the "side window top height Hwu' of a typical passenger car" is set to 2.0 m (meters). That is, the light projecting unit 11a of the laser scanner 11 according to this embodiment is installed at a position lower than 2.0 m (sensor height Hs<2.0 m). Therefore, it is more preferable that the height of the light projecting unit 11a of the laser scanner 11 (sensor height Hs) is lower than 2.0 m, and this allows the configuration to scan the interior ceiling C of both freight cars (FIG. 4) and passenger cars (FIG. 7). However, if the sensor height Hs is close to 2.0 m, in a passenger car, the light projecting unit 11a and the interior ceiling C are horizontally aligned at approximately the same height, and the range of the entire scanning range of the laser light that is irradiated onto the surface of the interior ceiling C becomes extremely narrow. The same can be said for a minivan, whose roof height is approximately 2.0 m. Therefore, it is more preferable that the sensor height Hs is 1.8 m or less.

[0055] On the other hand, if the sensor height Hs is set too low, particularly in a freight car, the incident angle of the laser light L to the side window W becomes large, so it is expected that the laser light L that passes through the side window W will have difficulty reaching the back (+Y direction) of the driver's cab. Here, in any vehicle, the bottom end of the side window W is at least located higher than the tires. Therefore, the sensor height Hs is set at a position higher than 0.5 m above the road surface (≒ tire height). More preferably, the sensor height Hs is set to be equal to the side window bottom height Hwd (FIG. 4) of a typical freight car, or slightly lower than it, taking into account the distance m. Here, the "side window bottom height Hwd of a typical freight car" is set to 1.6 m in this embodiment. Based on this, the sensor height Hs is preferably set to 1.4 m or more.

[0056] As described above, the light-projecting unit 11a of the laser scanner 11 according to this embodiment is set at a height that allows scanning of the interior ceiling through a side window of the vehicle A. As an example, the light-projecting unit 11a is installed at a position higher than 0.5 m above the road surface. Moreover, the most preferable condition for the sensor height Hs in this embodiment is 1.4 m≦Hs≦1.8 m. By satisfying this condition, the laser scanner 11 can scan the interior ceiling C of a freight vehicle or passenger vehicle traveling on the lane R, and can further scan the interior ceiling C to the far side (+Y direction side) of the driver's cab.

[0057] (Vehicle A is a sports car) FIG. 8 shows a state in which the laser light L is irradiated when the vehicle A is a sports car with a relatively low vehicle height.

[0058] It is assumed that the side window top height Hwu2 of a typical sports car is lower than the sensor height Hs, so that the interior ceiling of the vehicle A, which is a sports car, cannot be scanned with the laser light L projected from the light projecting unit 11a.

[0059] However, as shown in Fig. 8, for vehicle A, which is a low-height sports car, the entire bonnet surface B in the lane width direction can be scanned with laser light L projected toward the road surface (-Z direction side). In this way, when vehicle A is a sports car, the bonnet surface B is included in the scanning surface, and as a result, the scan information includes information corresponding to the vehicle width of vehicle A.

[0060] (If vehicle A is an open-top car) FIG. 9 shows a state in which the laser light L is irradiated when the vehicle A is an open-top car with no roof.

[0061] In the case of an open-top car that does not have a roof, the laser light L projected from the light-projecting unit 11a cannot scan the interior ceiling as shown in FIGS.

[0062] 9, for vehicle A which is an open-top car, if light-projecting unit 11a is located at a position higher than the height Hwd3 of the bottom edge of the side window of a typical open-top car, it is possible to scan the inner surface D of the door on the opposite side (+Y direction side) in the vehicle cabin with laser light L. In this way, when vehicle A is an open-top car, the inner surface D of the door on the opposite side (+Y direction side) in the vehicle cabin is included in the scanning surface, and as a result, the scan information includes information corresponding to the vehicle width of vehicle A.

[0063] (Action and effect) As described above, the vehicle type discrimination device 10 according to the first embodiment includes an acquisition unit 1000 that acquires scan information SD from the laser scanner 11, which is a laser scanner provided on only one side of the road and is capable of scanning the laser light L projected from the light-projecting unit 11a along a plane (XZ plane) that intersects with the lane direction, a vehicle width measurement unit 1002 that measures the vehicle width of vehicle A traveling on lane R based on the acquired scan information SD, and a vehicle type discrimination unit 1003 that discriminates the vehicle type classification of vehicle A from the vehicle width measurement result.

[0064] In this way, the width of a traveling vehicle can be measured using only a laser scanner installed on one side of the road. Therefore, there is no need to install a large support member such as a gantry, and there is also no need to prepare two reflective sensors, making it possible to realize vehicle type discrimination based on vehicle width with a simple configuration. As described above, the vehicle type discrimination device 10 according to the first embodiment can measure the vehicle width with a simple configuration.

[0065] In addition, the vehicle width measurement unit 1002 in this embodiment determines the vehicle width based on the position of the farthest observation point p2 and the position of the closest observation point p1 within a predetermined range (effective range Q) in the lane width direction for the light projection unit 11a of the laser scanner 11. In this way, the length equivalent to the width of vehicle A can be measured with a simple calculation.

[0066] Moreover, the vehicle width measurement unit 1002 according to this embodiment extracts the position of the farthest observation point p2 and the position of the closest observation point p1 from all of the multiple pieces of scan information SD acquired while the vehicle A is traveling. In this way, the vehicle width is measured using all of the multiple scan information SD acquired while one vehicle A is passing, thereby improving the measurement accuracy. For example, the area in the running direction (±X direction) where the side window W of vehicle A (Figs. 1 and 4), which is a freight vehicle, exists is limited, but by continuously acquiring scan information while the vehicle is running, it is possible to ensure that scan information in the area where the side window W exists is not missed. The same effect can be obtained for the bonnet surface B of a sports car (Fig. 8) and the inner surface D of the opposite door of an open-top car (Fig. 9).

[0067] In other embodiments, the process of calculating the vehicle width from the scan information can be changed as appropriate without being limited to the above-mentioned embodiment. For example, a more likely calculation result of the vehicle width can be obtained through a statistical analysis of each observation point p in the entirety of the multiple scan information SD (FIG. 6) obtained for one vehicle A.

[0068] (Other embodiments) In the above-described first embodiment, the light projecting unit 11a is described as being installed at a height capable of scanning the surface of the interior ceiling C through a side window of the vehicle A. However, other embodiments are not limited to this aspect. For example, in another embodiment, the light projecting unit 11a may be at a height capable of scanning the floor surface (including seats) inside the vehicle A or the inner surface of the opposite door or side wall through a side window of the vehicle A. Even with such a configuration, the length equivalent to the vehicle width of the vehicle A can be measured from the scan result (scan information).

[0069] However, in this case, if the sensor height Hs is set too high, the incident angle of the laser light L with respect to the side window W becomes large, and it is assumed that the laser light L that passes through the side window W will have difficulty reaching the back of the cab (+Y direction side). Here, the upper limit of the height of a vehicle body (excluding cargo) that can be driven on public roads is legally set at 3.8 m, and the upper ends of the side windows of almost all vehicles that drive on public roads are located at a position lower than 3.8 m above the road surface. Therefore, by setting the sensor height Hs lower than 3.8 m, it becomes possible to scan the interior floor or the inner surface of the opposite door or side wall for more vehicles that drive on lane R.

[0070] In the first embodiment, the sensor height Hs is set to 1.4m≦Hs≦1.8m as the optimum condition for the sensor height Hs, but this condition is also valid in the present embodiment. That is, by setting the height of the light projecting unit 11a to 1.4m to 1.8m from the road surface, it is possible to measure not only the ceiling surface but also the interior floor surface and the inner surfaces of the doors, etc., for a one-box car. Also, for a passenger car or a compact car, it is possible to scan the bonnet and trunk surfaces in addition to the ceiling surface, the interior floor surface, and the inner surfaces of the doors, etc., for many vehicles traveling on the lane R. That is, it is possible to scan the ceiling surface, the interior floor surface, and the inner surfaces of the doors, etc., and therefore it is possible to measure the length equivalent to the vehicle width with even greater accuracy. However, the scanned inner surface does not necessarily have to include the interior ceiling and floor of the vehicle. According to the laser scanner 11 according to each embodiment, the outer surface of the sensor installation side (-Y direction side) can be measured for most vehicles, so if the inner surface (not including the ceiling and floor, but only the inner surface of the door or side wall) on the side farther from the sensor installation side (+Y direction side) can be measured, a length highly correlated with the vehicle width of the vehicle can be measured from the difference.

[0071] The vehicle type discrimination device 10 according to this embodiment has been described as performing vehicle width measurement (step S4) to vehicle type discrimination processing (step S5) after the exit of vehicle A is detected (step S3) as per the processing flow shown in FIG. 3, but other embodiments are not limited to this. For example, the vehicle type discrimination device 10 according to another embodiment may be configured to sequentially repeat vehicle width measurement processing (step S4) on scan information acquired moment by moment while vehicle A is passing, and when a vehicle width that can uniquely identify the vehicle type classification is measured, output the discrimination result of the vehicle type classification at that timing (while vehicle A is passing).

[0072] In the above embodiment, the vehicle width measurement device has been described as having its components (acquisition unit 1000, detection unit 1001, and vehicle width measurement unit 1002) included as functions within the vehicle type discrimination device 10, but this is not limited to the above in other embodiments. In other words, the vehicle width measurement device may be used independently. For example, a vehicle width measuring device may be used to measure the width of a traveling vehicle and notify a host device of the measurement result, thereby determining whether or not the vehicle can enter a narrow passage. In addition, the vehicle width measuring device may be used to measure the width of a moving vehicle and notify a higher-level device of the measurement result, thereby guiding the moving vehicle to a passage with a lane width that is suitable for driving. Furthermore, the vehicle width measuring device may be used to control an automated machine such as an automated guided vehicle by measuring the width of an incoming vehicle and notifying the automated machine.

[0073] In the above-described embodiment, the various processes of the vehicle type discrimination device 10 are stored in a computer-readable recording medium in the form of a program, and the computer reads and executes this program to perform the various processes. The computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. The computer program may be distributed to a computer via a communication line, and the computer that receives the program may execute the program.

[0074] The program may be for implementing some of the above-mentioned functions, or may be a so-called differential file (differential program) that can implement the above-mentioned functions in combination with a program already recorded in the computer system.

[0075] As described above, several embodiments according to the present disclosure have been described, but 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, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention.

[0076] <Additional Notes> The vehicle width measurement device, the vehicle type discrimination device 10, the vehicle type discrimination system 1, the vehicle width measurement method and the program described in each embodiment can be understood, for example, as follows.

[0077] (1) The vehicle width measuring device of the first embodiment is a laser scanner provided on only one side of the road, and includes an acquisition unit 1000 that acquires scan information SD including distance measurement results for each scanning angle from a laser scanner 11 that is capable of scanning laser light L projected from a light-projecting unit 11a along a plane (YZ plane) intersecting with the lane direction (±X direction), and a vehicle width measuring unit 1002 that measures the vehicle width of a vehicle A traveling on a lane R based on the acquired scan information SD.

[0078] (2) In the vehicle width measuring device of the second embodiment, the vehicle width measuring unit 1002 determines the vehicle width based on the position of the farthest observation point p2 and the position of the closest observation point p1 within a predetermined range (effective range Q) in the lane width direction (±Y direction) for the light-projecting unit 11a of the laser scanner 11.

[0079] (3) In the vehicle width measuring device of the third aspect, the vehicle width measuring unit 1002 extracts the position of the farthest observation point p2 and the position of the closest observation point p1 from all of the multiple scan information SD acquired while the vehicle A is traveling.

[0080] (4) A vehicle type discrimination device 10 according to a fourth aspect includes a vehicle width measurement device according to any one of (1) to (3) above, and a vehicle type discrimination unit 1003 that discriminates the vehicle type category from the vehicle width measurement result.

[0081] (5) A vehicle type discrimination system 1 according to a fifth aspect includes the vehicle type discrimination device 10 described above in (4) and a laser scanner 11.

[0082] (6) In the vehicle type discrimination system 1 according to the sixth embodiment, the light projecting unit 11a is located at a height capable of scanning the interior ceiling (interior ceiling C) of the vehicle A through a side window.

[0083] (7) In the vehicle type discrimination system 1 according to the seventh aspect, the light projecting unit 11a is provided at a position that is higher than 0.5 m above the road surface of the lane R.

[0084] (8) In the vehicle type discrimination system 1 according to the eighth aspect, the light projecting unit 11a is set at a height capable of scanning the floor surface in the vehicle interior or the inner surface of the door on the opposite side.

[0085] (9) In the vehicle type discrimination system 1 according to the ninth aspect, the light projecting unit 11a is provided at a position lower than 3.8 m above the road surface of the lane R.

[0086] (10) In the vehicle type discrimination system 1 according to the tenth aspect, the light projecting unit 11a is provided at a height of 1.4 m to 1.8 m above the road surface of the lane R.

[0087] (11) A vehicle width measurement method according to an eleventh aspect includes the steps of acquiring scan information including distance measurement results for each scan angle from a laser scanner provided on only one side of the road and capable of scanning laser light projected from a light-projecting unit along a plane intersecting the lane direction, and measuring the vehicle width of a vehicle traveling in the lane based on the acquired scan information.

[0088] (12) The program relating to the twelfth aspect causes the computer of the vehicle type discrimination device 10 to execute the steps of acquiring scan information including distance measurement results for each scan angle from a laser scanner provided on only one side of the road and capable of scanning laser light projected from a light-projecting unit along a plane intersecting the lane direction, and measuring the vehicle width of a vehicle traveling in the lane based on the acquired scan information. [Explanation of symbols]

[0089] 1 Vehicle type identification system 10 Vehicle type identification device (vehicle width measurement device) 100 CPU 1000 acquisition department 1001 Detection unit 1002 Vehicle width measurement section 1003 Vehicle Type Identification Unit 101 Communication Interface 102 Recording media 11 Laser scanner 11a Light projecting section

Claims

1. A laser scanner provided on only one side of a road, the laser scanner being capable of scanning a laser beam projected from a light-projecting unit along a plane intersecting a lane direction; a vehicle type discrimination device including: a vehicle width measurement device that acquires scan information including a distance measurement result for each scan angle from the laser scanner, and measures a vehicle width of a vehicle traveling on a lane based on the acquired scan information; and a vehicle type discrimination unit that discriminates a vehicle type category of the vehicle from the vehicle width measurement result, The light projecting unit is at a height capable of scanning the ceiling of the vehicle through a side window of the vehicle. Vehicle identification system.

2. The light projecting unit is provided at a position higher than 0.5 m above the road surface of the lane. The vehicle type discrimination system according to claim 1 .

3. A laser scanner provided on only one side of a road, the laser scanner being capable of scanning a laser beam projected from a light-projecting unit along a plane intersecting a lane direction; a vehicle type discrimination device including: a vehicle width measurement device that acquires scan information including a distance measurement result for each scan angle from the laser scanner, and measures a vehicle width of a vehicle traveling on a lane based on the acquired scan information; and a vehicle type discrimination unit that discriminates a vehicle type category of the vehicle from the vehicle width measurement result, The light projecting unit is at a height capable of scanning the floor surface of the interior of the vehicle or the inner surface of the door on the opposite side through a side window of the vehicle. Vehicle identification system.

4. The light projecting unit is provided at a position lower than 3.8 m above the road surface of the lane. The vehicle type discrimination system according to claim 3.

5. The light projecting unit is provided at a height of 1.4 m to 1.8 m above the road surface of the lane. The vehicle type discrimination system according to any one of claims 1 to 4.

6. The vehicle width measuring device specifies the vehicle width based on the position of the farthest observation point and the position of the closest observation point within a predetermined range in the lane width direction with respect to the light projecting unit of the laser scanner. The vehicle type discrimination system according to any one of claims 1 to 4.

7. The vehicle width measuring device extracts the position of the farthest observation point and the position of the nearest observation point from all of a plurality of pieces of scan information acquired while the vehicle is traveling. The vehicle type discrimination system according to claim 6.

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