Commander detector, commander detection method, and program

Abstract

To provide a vehicle length detector that can accurately detect whether or not a vehicle length is equal to or more than a threshold value, regardless of an installation environment of the vehicle length detector.SOLUTION: A vehicle length detector includes: a first time acquisition unit that acquires a first time indicating a time when a vehicle has passed an approach detection position based on a vehicle detection signal indicating whether or not the vehicle is present at the approach detection position in a lane; a second time acquisition unit that acquires a second time indicating a time when the vehicle has reached a vehicle length determination position based on a vehicle length detection signal indicating whether or not the vehicle is present at the vehicle length determination position downstream in a vehicle travel direction from the approach detection position; an offset processing unit that offsets the second time by an offset amount corresponding to an installation environment of the vehicle length detector; and a determination unit that determines that the vehicle length is equal to or more than a threshold value when the second time after offsetting is earlier than the first time.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a vehicle length detector, a vehicle length detection method, and a program.

Background Art

[0002] In recent years, technologies for automatically measuring the number of vehicles and vehicle characteristics (external dimensions, number of axles, etc.) using sensors and the like have been used.

[0003] For example, Patent Document 1 describes a technique for detecting vehicles existing in a predetermined area from an image captured by a camera and measuring traffic volume.

[0004] In addition, in facilities used by vehicles such as toll roads and parking lots, there are cases where usage fees are changed according to the size of the vehicle, or entry is restricted. For example, a vehicle length detection system for measuring the vehicle length may be provided at a tollgate of a toll road.

[0005] FIG. 11 is a diagram showing an example of a conventional vehicle length detection system. As shown in FIG. 11, the vehicle length detection system 9 includes a vehicle detector 91 provided on the roadside (on the island I) of the lane L of the tollgate, and a vehicle length detector 92. The vehicle detector 91 is installed at an entry detection position X1 in the vehicle traveling direction (±X direction), and detects whether or not the vehicle A exists at the entry detection position X1. Based on the detection result of the vehicle detector 91, it is possible to detect that the vehicle A has reached the entry detection position X1 and that the vehicle A has passed through the entry detection position X1.

[0006] In addition, the vehicle length detector 92 is installed at a specified position X2 on the downstream side (+X side) in the vehicle traveling direction from the vehicle detector 91, and detects whether the vehicle A is present at the specified position X2. Further, the vehicle length detector 92 determines whether the vehicle length of the vehicle A is equal to or greater than a threshold value D1 based on the detection result of the vehicle detector 91 and its own detection result. For example, when it is desired to determine whether the vehicle A is a predetermined vehicle type, the threshold value D1 is set based on the maximum vehicle length of the predetermined vehicle type. When the predetermined vehicle type is a light motor vehicle, the threshold value D1 is set to, for example, "3.65 m", which is greater than the maximum vehicle length of the light motor vehicle. The specified position X2 is a position separated from the entry detection position X1 by the threshold value D1.

[0007] When the vehicle length detector 92 detects that the vehicle A is present (has reached) at the specified position X2 after the vehicle has passed through the entry detection position X1, it determines that the vehicle length of the vehicle A is less than the threshold value. Further, when the vehicle length detector 92 detects that the vehicle A is present at the specified position X2 before the vehicle A passes through the entry detection position X1, it determines that the vehicle length of the vehicle A is equal to or greater than the threshold value. Based on the determination result of the vehicle length detector 92, it becomes possible to identify whether the vehicle A is a predetermined vehicle type (light motor vehicle).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, depending on the installation environment, such as the presence of an obstacle on Island I, it may not be possible to place the vehicle length detector 92 at the specified position X2. For example, when the vehicle length detector 92 is placed upstream (-X side) of the specified position X2 to avoid an obstacle, the distance between the vehicle detector 91 (entry detection position X1) and the vehicle length detector 92 becomes shorter than the threshold value D1. In this case, although vehicle A is a light vehicle (vehicle length less than the threshold value D1), the vehicle length detector 92 may erroneously determine that the vehicle length of this vehicle A is equal to or greater than the threshold value D1.

[0010] The present disclosure has been made in view of such problems, and provides a vehicle length detector, a vehicle length detection method, and a program capable of accurately detecting whether the vehicle length of a vehicle is equal to or greater than a threshold value regardless of the installation environment of the vehicle length detector.

Means for Solving the Problems

[0011] According to one aspect of the present disclosure, a vehicle length detector is a vehicle length detector that detects the vehicle length of a vehicle traveling in a lane, and based on a vehicle detection signal indicating whether the vehicle exists at an entry detection position of the lane, a first time acquisition unit that acquires a first time indicating the time when the vehicle has passed the entry detection position, a second time acquisition unit that acquires a second time indicating the time when the vehicle has reached a vehicle length determination position on the downstream side in the vehicle traveling direction from the entry detection position, based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position, an offset processing unit that offsets the second time by an offset amount corresponding to the installation environment of the vehicle length detector, and a determination unit that determines that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time.

[0012] According to one aspect of the present disclosure, a vehicle length detection method is a vehicle length detection method for detecting the vehicle length of a vehicle traveling in a lane by a vehicle length detector, including: obtaining a first time indicating a time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; obtaining a second time indicating a time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position; offsetting the second time by an offset amount according to the installation environment of the vehicle length detector; and determining that the vehicle length of the vehicle is equal to or greater than a threshold when the offset second time is earlier than the first time.

[0013] According to one aspect of the present disclosure, a program causes a vehicle length detector for detecting the vehicle length of a vehicle traveling in a lane to obtain a first time indicating a time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane, obtain a second time indicating a time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position, offset the second time by an offset amount according to the installation environment of the vehicle length detector, and determine that the vehicle length of the vehicle is equal to or greater than a threshold when the offset second time is earlier than the first time.

Advantages of the Invention

[0014] According to the vehicle length detector, the vehicle length detection method, and the program according to the present disclosure, it is possible to accurately detect whether the vehicle length of a vehicle is equal to or greater than a threshold regardless of the installation environment of the vehicle length detector.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0016] <First Embodiment> Hereinafter, a vehicle length detection system and a vehicle length detector according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 8.

[0017] (Overall Configuration) FIG. 1 is a diagram showing the overall configuration of a vehicle length detection system according to a first embodiment of the present disclosure. In the example of FIG. 1, the vehicle length detection system 1 is provided at the tollgate of a toll road and measures the vehicle length of vehicle A traveling in the lane L of the tollgate. Further, a vehicle type discrimination device (not shown) for discriminating the vehicle type of vehicle A based on the vehicle length and the like of vehicle A, and a toll collection system (not shown) for collecting the toll according to the vehicle type may be provided at the tollgate. In addition, in other embodiments, the vehicle length detection system 1 may be provided in various facilities that require measurement of the vehicle length for vehicle type discrimination, such as a parking lot that collects parking fees by vehicle type, or a road that restricts traffic for specific vehicle types.

[0018] As shown in FIG. 1, the vehicle length detection system 1 includes a vehicle detector 10 and a vehicle length detector 20.

[0019] The vehicle detector 10 is installed at the approach detection position X1 in the vehicle traveling direction (±X direction) on the roadside (on the island I) of the lane L. The vehicle detector 10 is a so-called transmissive vehicle detector and has a pair of a light projector 11 and a light receiver 12 installed opposite each other across the lane L. The vehicle detector 10 outputs a vehicle detection signal that can distinguish the presence or absence of a vehicle at the approach detection position X1 based on whether the light receiver 12 receives the light projected from the light projector 11. The vehicle detector 10 outputs a vehicle detection signal (OFF) indicating that vehicle A does not exist at the approach detection position X1 while the light receiver 12 is receiving light. On the other hand, the vehicle detector 10 outputs a vehicle detection signal (ON) indicating that vehicle A exists at the approach detection position X1 while the light receiver 12 is not receiving light.

[0020] The vehicle length detector 20 is installed at the vehicle length determination position X3 on the roadside of the lane L (on the island I), downstream (+X side) of the entry detection position X1 in the vehicle traveling direction. The vehicle length detector 20 has a pair of a light projector 25 and a light receiver 26, similar to the vehicle detector 10. The vehicle length detector 20 outputs a vehicle length detection signal that can distinguish the presence or absence of a vehicle at the vehicle length determination position X3 based on whether the light receiver 26 receives the light projected from the light projector 25. While the light receiver 26 is receiving light, the vehicle length detector 20 outputs a vehicle length detection signal (OFF) indicating that there is no vehicle at the vehicle length determination position X3. On the other hand, while the light receiver 26 is not receiving light, the vehicle length detector 20 outputs a vehicle length detection signal (ON) indicating that there is a vehicle at the vehicle length determination position X3.

[0021] Also, the vehicle length detector 20 according to the present embodiment detects whether the vehicle length of vehicle A is equal to or greater than a threshold value D1. The threshold value D1 is set to a length that can distinguish whether it is a predetermined vehicle type. For example, when the predetermined vehicle type is a light automobile, the threshold value D1 is set to a value greater than the maximum vehicle length of a light automobile (for example, "3.65 m").

[0022] While the vehicle detection signal is "ON" (vehicle A is present at the entry detection position X1), when the vehicle length detection signal becomes "ON", it is determined that the vehicle length of this vehicle A is equal to or greater than the threshold value D1. On the other hand, after the vehicle detection signal switches from "ON" to "OFF" (vehicle A has passed through the entry detection position X1), when the vehicle length detection signal becomes "ON", it is determined that the vehicle length of this vehicle A is less than the threshold value D1.

[0023] As shown in FIG. 11, the conventional vehicle length detector 92 had to be arranged at a specified position X2 where the distance from the vehicle detector 91 (entry detection position X1) is the threshold value D1. However, as described above, when there are obstacles on the island I, etc., there may be cases where the vehicle length detector 92 cannot be installed at the specified position X2.

[0024] Therefore, when the vehicle length detector 20 according to this embodiment is installed at a vehicle length determination position X3 different from the specified position X2, the time when the vehicle length detection signal becomes "ON" is adjusted according to the distance D2 from the entry detection position X1 to the vehicle length determination position X3 (or the distance D3 from the specified position X2 to the vehicle length determination position X3), so that it is possible to accurately determine whether the vehicle length is equal to or greater than the threshold D1 as if the vehicle length detector 20 were installed at the specified position X2.

[0025] (Functional Configuration) FIG. 2 is a block diagram showing the functional configuration of the vehicle length detector according to the first embodiment of the present disclosure. As shown in FIG. 2, the vehicle length detector 20 further includes a processor 21, a memory 22, a storage 23, and a communication interface 24.

[0026] The processor 21 functions as a first time acquisition unit 210, a second time acquisition unit 211, an offset processing unit 212, and a determination unit 213 by operating according to a predetermined program.

[0027] The first time acquisition unit 210 acquires a first time indicating the time when the vehicle A has passed the entry detection position X1 (the vehicle detection signal has switched from "ON" to "OFF") based on a vehicle detection signal indicating whether the vehicle A exists at the entry detection position X1 of the lane L.

[0028] The second time acquisition unit 211 acquires a second time indicating the time when the vehicle A has reached the vehicle length determination position X3 (the vehicle length detection signal has switched from "OFF" to "ON") based on a vehicle length detection signal indicating whether the vehicle A exists at the vehicle length determination position X3.

[0029] The offset processing unit 212 offsets the second time by an offset amount according to the installation environment of the vehicle length detector 20. The offset processing unit 212 according to this embodiment offsets the second time by an offset amount according to the distance from the entry detection position X1 to the vehicle length determination position X3.

[0030] When the second time after offset is before the first time, the determination unit 213 determines that the vehicle length of vehicle A is greater than or equal to the threshold value D1.

[0031] The predetermined program executed by the processor 21 is stored in a computer-readable recording medium. The computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. Further, this computer program may be distributed to a computer via a communication line, and the computer that has received this distribution may execute the program. Furthermore, this program may be for realizing a part of the above-described functions. Furthermore, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

[0032] The memory 22 has a memory area necessary for the operation of the processor 21.

[0033] The storage 23 is a so-called auxiliary storage device, such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc.

[0034] The communication interface 24 is an interface for transmitting and receiving various signals to and from external devices. For example, the communication interface 24 receives a vehicle detection signal from the vehicle detector 10. Also, when a vehicle type discrimination device (not shown) is provided at the tollgate, the communication interface 24 may transmit a signal indicating the determination result of the vehicle length detector 20 (whether the vehicle length of vehicle A is greater than or equal to the threshold value D1) to the vehicle type discrimination device.

[0035] (Processing Flow) FIG. 3 is a flowchart showing an example of the processing of the vehicle length detector according to the first embodiment of the present disclosure. Hereinafter, an example of the processing of the vehicle length detector 20 will be described with reference to FIG. 3.

[0036] Based on the vehicle detection signal received from the vehicle detector 10, the first time acquisition unit 210 detects that vehicle A has entered the entry detection position X1 of lane L (step S10). Specifically, when the vehicle detection signal received from the vehicle detector 10 switches from "OFF" to "ON", the first time acquisition unit 210 detects that vehicle A has entered the entry detection position X1.

[0037] Next, when the vehicle detection signal received from the vehicle detector 10 switches from "ON" to "OFF", the first time acquisition unit 210 detects that vehicle A has passed the entry detection position X1 (step S11).

[0038] Also, the first time acquisition unit 210 acquires the first time when it detects that vehicle A has passed the entry detection position X1 (step S12).

[0039] In parallel with the processing of the first time acquisition unit 210 (steps S10 to S12), the second time acquisition unit detects that vehicle A has reached the vehicle length determination position X3 based on the vehicle length detection signal (step S13). Specifically, when the vehicle length detection signal switches from "OFF" to "ON", the second time acquisition unit 211 detects that vehicle A has reached the vehicle length determination position X3.

[0040] Also, the second time acquisition unit 211 acquires the second time when it detects that vehicle A has reached the vehicle length determination position X3 (step S14).

[0041] Next, the offset processing unit 212 offsets the second time by an offset amount corresponding to the distance D2 from the entry detection position X1 to the vehicle length determination position X3 (step S15).

[0042] FIG. 4 is a first diagram for explaining the function of the vehicle length detector according to the first embodiment of the present disclosure. FIG. 5 is a first diagram showing an example of the vehicle detection signal and the vehicle length detection signal according to the first embodiment of the present disclosure. First, as shown in FIG. 4, an example will be described in which the vehicle length determination position X3 is on the upstream side (-X side) of the vehicle traveling direction from the specified position X2 (i.e., "distance D2 < threshold D1").

[0043] The vehicle A illustrated in FIG. 4 enters the entry detection position X1 at time t1 and passes through the entry detection position X1 at time t3. Then, as shown in FIG. 5, the vehicle detection signal switches from "OFF" to "ON" at time t1 and from "ON" to "OFF" at time t3. At this time, the first time acquisition unit 210 acquires time t3 as the first time (step S12 in FIG. 3).

[0044] Also, the vehicle A illustrated in FIG. 4 reaches the vehicle length determination position X3, which is the actual installation position of the vehicle length detector 20, at time t2 before time t3. Then, as shown by the dashed line in FIG. 5, the vehicle length detection signal switches from "OFF" to "ON" at time t2. At this time, the second time acquisition unit 211 acquires time t2 as the second time (step S14 in FIG. 3).

[0045] Also, based on the second time t2, the offset processing unit 212 obtains the time at which it is estimated that the vehicle length detection signal switches to "ON" when the vehicle length detector 20 is hypothetically installed at the specified position X2. Specifically, when the distance D2 from the entry detection position X1 to the vehicle length determination position X3 is shorter than the threshold D1 (the vehicle length determination position X3 is on the upstream side of the specified position X2), the offset processing unit 212 offsets by delaying the second time by a predetermined time (step S15 in FIG. 3). Then, as shown in FIG. 5, the timing at which the vehicle length detection signal switches to "ON" is offset to time t4, which is a predetermined time delayed from the second time t2.

[0046] FIG. 6 is a second diagram for explaining the function of the vehicle length detector according to the first embodiment of the present disclosure. FIG. 7 is a second diagram showing an example of the vehicle detection signal and the vehicle length detection signal according to the first embodiment of the present disclosure. Next, as shown in FIG. 6, an example will be described in which the vehicle length determination position X3 is on the downstream side (+X side) in the vehicle traveling direction from the specified position X2 (i.e., "distance D2 > threshold value D1").

[0047] The vehicle A illustrated in FIG. 6 enters the entry detection position X1 at time t11 and passes the entry detection position X1 at time t13. Then, as shown in FIG. 7, the vehicle detection signal switches from "OFF" to "ON" at time t11 and switches from "ON" to "OFF" at time t13. At this time, the first time acquisition unit 210 acquires time t13 as the first time (step S12).

[0048] Also, the vehicle A illustrated in FIG. 6 reaches the vehicle length determination position X3, which is the actual installation position of the vehicle length detector 20, at time t14 after time t13. Then, as shown by the dashed line in FIG. 7, the vehicle length detection signal switches from "OFF" to "ON" at time t14. At this time, the second time acquisition unit 211 acquires time t14 as the second time (step S14).

[0049] Further, based on the second time t14, the offset processing unit 212 obtains the time at which it is estimated that the vehicle length detection signal switches to "ON" when the vehicle length detector 20 is hypothetically installed at the specified position X2. Specifically, when the distance D2 from the entry detection position X1 to the vehicle length determination position X3 is longer than the threshold value D1 (the vehicle length determination position X3 is on the downstream side from the specified position X2), the offset processing unit 212 offsets by advancing the second time by a predetermined time (step S15). Then, as shown in FIG. 7, the timing at which the vehicle length detection signal switches to "ON" is offset to time t12, which is a predetermined time earlier than the second time t14.

[0050] FIG. 6 is a diagram showing an example of the offset amount according to the first embodiment of the present disclosure. The offset processing unit 212 determines an offset time (predetermined time), for example, by referring to an offset amount table T1 (FIG. 6) pre-recorded in the storage 23. As shown in FIG. 6, the offset amount table T1 associates the distance D3 between the specified position X2 and the vehicle length determination position X3 with the offset time. For example, when the distance D3 is "-20 cm" (the vehicle length determination position X3 is arranged 20 cm upstream of the specified position X2), the offset time is "+v1" (delayed by v1 seconds). Also, when the distance D3 is "0 cm", that is, when the vehicle length detector 20 is installed at the specified position X2, the offset time is "0 seconds". Note that the vehicle length detector 20 records the value of the distance D3 input by the operator at the time of installation in the storage 23. The offset processing unit 212 determines the offset time based on the distance D3 recorded in the storage 23 and the offset amount table T1. When the arrangement of the vehicle length detector 20 is changed, a new distance D3 is input by the operator. Thereby, the offset processing unit 212 can determine an appropriate offset time according to the changed arrangement of the vehicle length detector 20.

[0051] Further, the storage 23 may record an offset amount table T1 for each assumed speed of the lane L. The assumed speed is, for example, the speed limit of the lane L. In this case, the offset processing unit 212 extracts the offset amount table T1 corresponding to the speed limit of the lane L input by the operator from the storage 23 and determines the offset time according to the distance D3.

[0052] Next, the determination unit 213 compares the first time with the second time after offset (step S16). When the second time after offset is before the first time (step S16; YES), that is, when it is presumed that vehicle A has reached the specified position X2 before passing through the entry detection position X1, the determination unit 213 determines that the vehicle length of vehicle A is equal to or greater than the threshold value D1 (step S17). On the other hand, when the second time after offset is after the first time (step S16; NO), that is, when it is presumed that vehicle A has reached the specified position X2 after passing through the entry detection position X1, the determination unit 213 determines that the vehicle length of vehicle A is less than the threshold value D1 (step S18).

[0053] In the examples of FIGS. 4 and 5, it is assumed that the vehicle length of vehicle A is shorter than the threshold value D1. For example, when the conventional vehicle length detector 92 is installed at the specified position X2, the timing at which the vehicle length detection signal becomes "ON" is time t4. Since time t4 is after the first time t3 when the vehicle detection signal becomes "OFF", the conventional vehicle length detector 92 can correctly determine that the vehicle length of vehicle A is shorter than the threshold value D1. However, as in the examples of FIGS. 4 and 5, when the vehicle length detector 92 is arranged on the upstream side (-X side) of the specified position X2, the actual time when the vehicle length detection signal becomes "ON" is time t2 (the second time), which is earlier than time t4. At this time, since the second time t2 is before the first time t3, there is a possibility of misjudging that the vehicle length of vehicle A is equal to or greater than the threshold value D1 when using the conventional vehicle length detector 92.

[0054] In contrast, as shown in FIGS. 4 and 5, the offset processing unit 212 of the vehicle length detector 20 according to the present embodiment offsets the second time t2 so as to delay it in response to the distance D2 from the entry detection position X1 to the vehicle length determination position X3 being shorter than the threshold value D1 (step S15). Thereby, the offset processing unit 212 can simulate the time t4 at which it is presumed that the vehicle length detection signal of vehicle A becomes "ON" when the vehicle length detector 20 is installed at the specified position X2.

[0055] Also, as shown in FIG. 5, since the time t4 after offset is a time after the first time t3 (step S16; NO), the determination unit 213 can correctly determine that the vehicle length of this vehicle A is shorter than the threshold D1 (step S18). Even when the vehicle length detector 20 according to the present embodiment is installed upstream of the specified position X2 in this way, it is possible to accurately determine whether the vehicle length of the vehicle A is equal to or greater than the threshold D1.

[0056] Also, in the examples of FIGS. 6 and 7, it is assumed that the vehicle length of the vehicle A is longer than the threshold D1. For example, when the conventional vehicle length detector 92 is installed at the specified position X2, the timing at which the vehicle length detection signal becomes "ON" is the time t12. Since the time t12 is before the first time t13 when the vehicle detection signal becomes "OFF", the conventional vehicle length detector 92 can correctly determine that the vehicle length of the vehicle A is equal to or greater than the threshold D1. However, as in the examples of FIGS. 6 and 7, when the vehicle length detector 92 is arranged on the downstream side (+X side) of the specified position X2, the actual time when the vehicle length detection signal becomes "ON" is a time t14 (second time) later than the time t12. At this time, since the conventional vehicle length detector 92 determines that the second time t14 is a time after the first time t13, there is a possibility of misjudging that the vehicle length of the vehicle A is shorter than the threshold D1.

[0057] On the other hand, as shown in FIGS. 6 and 7, the offset processing unit 212 of the vehicle length detector 20 according to the present embodiment offsets so as to advance the second time t14 corresponding to the amount by which the distance D2 from the entry detection position X1 to the vehicle length determination position X3 becomes longer than the threshold D1 (step S15). Thereby, the offset processing unit 212 can simulate the time t12 at which it is estimated that the vehicle length detection signal of the vehicle A becomes "ON" when the vehicle length detector 20 is installed at the specified position X2.

[0058] Also, as shown in FIG. 7, since the time t12 after offset is before the first time t13 (step S16; YES), the determination unit 213 can correctly determine that the vehicle length of this vehicle A is equal to or greater than the threshold value D1 (step S17). Even when the vehicle length detector 20 according to the present embodiment is installed on the downstream side of the specified position X2 in this way, it is possible to accurately determine whether the vehicle length of the vehicle A is equal to or greater than the threshold value D1.

[0059] (Function, effect) As described above, the vehicle length detector 20 according to the present embodiment includes a first time acquisition unit 210 that acquires a first time indicating the time when the vehicle A has passed the entry detection position X1 based on the vehicle detection signal of the vehicle detector 10, and a second time acquisition unit 211 that acquires a second time indicating the time when the vehicle A has reached the vehicle length determination position X3 based on the vehicle length detection signal, an offset processing unit 212 that offsets the second time by an offset amount according to the installation environment of the vehicle length detector 20, and a determination unit 213 that determines that the vehicle length of the vehicle A is equal to or greater than the threshold value D1 when the offset second time is before the first time. Note that the installation environment in the present embodiment is the positional relationship between the actual installation position (vehicle length determination position X3) of the vehicle length detector 20 and the specified position X2.

[0060] By doing so, even when the vehicle length detector 20 is installed at a position different from the specified position X2, it is possible to accurately determine whether the vehicle length of the vehicle A is equal to or greater than the threshold value D1.

[0061] Also, when the distance D2 from the entry detection position X1 to the vehicle length determination position X3 is shorter than the threshold value D1, the offset processing unit 212 offsets the second time so as to delay it by a predetermined time.

[0062] By doing so, even when the vehicle length detector 20 is installed on the upstream side of the specified position X2, it is possible to accurately determine whether the vehicle length of the vehicle A is equal to or greater than the threshold value D1.

[0063] Further, when the distance D2 from the entry detection position X1 to the crew length determination position X3 is longer than the threshold value D1, the offset processing unit 212 offsets to advance the second time by a predetermined time.

[0064] By doing so, even when the crew length detector 20 is installed on the downstream side of the specified position X2, it is possible to accurately determine whether the crew length of the vehicle A is equal to or greater than the threshold value D1.

[0065] <Second Embodiment> Next, the vehicle length detection system 1 according to the second embodiment of the present disclosure will be described. The same reference numerals are given to the components common to the first embodiment, and the detailed description thereof will be omitted.

[0066] In the first embodiment, the processing in an installation environment where the crew length detector 20 cannot be arranged at the specified position X2 has been described. However, even if the crew length detector 20 can be arranged at the specified position X2, in a tollgate where many vehicles with special shapes travel, there is a possibility that the misjudgment of the crew length increases more than in other tollgates.

[0067] A vehicle with a special shape is, for example, a vehicle having a load protruding in the front-rear direction of the vehicle body. The load is, for example, a detachable article such as a spare tire, a carrier, or a ski board mounted on the carrier, which is attached to the rear of the vehicle. For example, at a tollgate near a ski resort during a predetermined period such as winter, it is assumed that the number of vehicles with a load such as a ski board attached will increase significantly.

[0068] Since such a load can be removed, it is necessary to exclude it from the measurement of the vehicle length. However, in the conventional vehicle length detection system 9, even after the rear end of the vehicle body of the vehicle has passed through the entry detection position X1, the vehicle detection signal remains "ON" while the load exists at the entry detection position X1. That is, when there is a load, the timing at which the vehicle detection signal turns "OFF" is later than when there is no load. Then, even if the vehicle length detected by the vehicle length detector 92 is less than the threshold value D1, there is a possibility that it may be erroneously determined that the vehicle length of this vehicle is equal to or greater than the threshold value D1.

[0069] Therefore, the vehicle length detector 20 according to the present embodiment can suppress a decrease in the determination accuracy of the vehicle length due to the influence of the load by adjusting the time when the vehicle length detection signal turns "ON" at a place where many vehicles having a load run.

[0070] FIG. 9 is a diagram for explaining the function of the vehicle length detector according to the second embodiment of the present disclosure. FIG. 10 is a diagram showing an example of the vehicle detection signal and the vehicle length detection signal according to the second embodiment of the present disclosure. Hereinafter, the details of the processing of the vehicle length detector 20 will be described with reference to FIGS. 9 to 10 and FIG. 3.

[0071] For example, as shown in FIG. 9, it is assumed that a load B (spare tire) is attached to the rear surface of the vehicle A. In the example of FIG. 9, the vehicle A enters the entry detection position X1 at time t21, and the vehicle detection signal turns "ON". Further, although the rear end of the vehicle body of the vehicle A passes through the entry detection position at time t22, since the presence of the load is detected by the vehicle detector 91, the vehicle detection signal turns "OFF" at time t24 when the load has passed through the entry detection position X1. Therefore, the first time acquisition unit 210 acquires time t24 as the first time (step S12 in FIG. 3).

[0072] Also, vehicle A reaches the specified position X2 (vehicle length determination position X3) at time t23, and at this point, the vehicle length detection signal becomes "ON". Therefore, the second time acquisition unit 211 acquires time t23 as the second time (step S14 in FIG. 3).

[0073] Also, the offset processing unit 212 determines the time at which it is estimated that the vehicle length detection signal will switch to "ON" when the load B is removed, assuming that vehicle A is carrying the load B. Specifically, the offset processing unit 212 offsets the second time so as to delay it by a predetermined time in consideration of the fact that the timing at which the vehicle detection signal becomes "OFF" is delayed by the amount of the load B being loaded (step S15 in FIG. 3). Then, as shown in FIG. 10, the timing at which the vehicle length detection signal switches to "ON" is offset to time t25, which is delayed by a predetermined time from the second time t23.

[0074] The offset processing unit 212 offsets the second time based on, for example, the offset time (predetermined time) pre-recorded in the storage 23. The offset time is preset based on, for example, the maximum length of the load B (for example, a length corresponding to one-tenth of the maximum vehicle length of a light motor vehicle) defined by laws and regulations.

[0075] Also, the storage 23 may record the offset time for each assumed speed of the lane L. The assumed speed is, for example, the speed limit of the lane L. In this case, the offset processing unit 212 reads out the offset time corresponding to the speed limit of the lane L input by the operator from the storage 23 and performs the offset processing.

[0076] Next, the determination unit 213 compares the first time with the second time after offset (step S16 in FIG. 3). When the second time after offset is before the first time (step S16 in FIG. 3; YES), the determination unit 213 determines that the vehicle length of vehicle A is equal to or greater than the threshold value D1 (step S17 in FIG. 3). On the other hand, when the second time after offset is after the first time (step S16; NO), the determination unit 213 determines that the vehicle length of vehicle A is less than the threshold value D1 (step S18 in FIG. 3).

[0077] In the examples of FIGS. 9 and 10, it is assumed that the vehicle length of vehicle A without the load is shorter than the threshold value D1. However, the vehicle detection signal does not turn "OFF" until the load B of vehicle A passes through the entry detection position X1. For this reason, the second time t23 when the vehicle length detection signal turns "ON" is before the first time t24 when the vehicle detection signal turns "OFF". Then, the conventional vehicle length detector 92 may erroneously determine that the vehicle length of vehicle A is equal to or greater than the threshold value D1.

[0078] In contrast, as shown in FIGS. 9 and 10, the offset processing unit 212 of the vehicle length detector 20 according to the present embodiment offsets the second time t2 by delaying it by a predetermined time on the assumption that vehicle A has a load B (step S15 in FIG. 3). Thereby, the offset processing unit 212 can simulate the time t25 at which it is estimated that the vehicle length detection signal of vehicle A turns "ON" when vehicle A removes the load B.

[0079] Also, as shown in FIG. 10, since the time t25 after offset is after the first time t24 (step S16 in FIG. 3; NO), the determination unit 213 can correctly determine that the vehicle length of this vehicle A is shorter than the threshold value D1 (step S18 in FIG. 3). The vehicle length detector 20 according to the present embodiment can reduce the possibility of erroneously determining that the vehicle length of vehicle A is equal to or greater than the threshold value D1 at a tollgate where vehicle A often has a load B attached.

[0080] In other embodiments, it may be possible to set whether the operator enables or disables the process of offsetting the second time. For example, at a tollgate near a ski resort, the operator enables the offset process during a period when the number of vehicles carrying loads, such as in winter, increases, and disables the offset process during other periods. This switching between enabling and disabling may be performed manually by the operator, or may be automatically switched to enabled only during the period set by the offset processing unit 212.

[0081] (Function, effect) As described above, in the vehicle length detector 20 according to the present embodiment, when the offset processing unit 212 is installed in an installation environment where the vehicle A having the load B travels, the offset processing unit 212 offsets the second time by delaying it by a predetermined time.

[0082] By doing so, the vehicle length detector 20 can reduce the possibility of misjudging that the vehicle length of the vehicle A is equal to or greater than the threshold value D1 in a place where the vehicle A often carries the load B.

[0083] 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, 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.

[0084] For example, in each of the above-described embodiments, an offset time corresponding to an assumed speed is set in advance, and the offset processing unit 212 has been described as using the speed limit of lane L as the assumed speed of lane L. However, the present invention is not limited to this. In other embodiments, the offset processing unit 212 may record the speeds of a plurality of vehicles traveling in lane L, and use the average speed obtained from the statistical information of the speeds of the plurality of vehicles as the assumed speed. The offset processing unit 212 calculates, for example, the speed of each vehicle based on the distance D2 from the entry detection position X1 to the vehicle length determination position X3 and the time from when the vehicle detection signal becomes "ON" until the vehicle length detection signal becomes "ON", and records it in the storage 23. When a predetermined number or more of speed samples are recorded, the offset processing unit 212 calculates the average speed of these speed samples and uses it as the assumed speed. Further, the offset processing unit 212 may calculate the average speed for each season, day of the week, and time zone, and use the average speed corresponding to the current date and time as the assumed speed. Thereby, the offset processing unit 212 can adjust the offset time more accurately according to the actual speed of the vehicles traveling in lane L.

[0085] In addition, the conductor detector 20 may record, as a log, the time when the vehicle detection signal switches between "ON" and "OFF", the time when the conductor detection signal switches between "ON" and "OFF", the offset time used for offset processing, the determination result of the conductor length, etc. in the storage 23. When the conductor detector 20 is connected to a maintenance computer (not shown), it may transmit the log recorded in the storage 23 so that an operator can check it via the maintenance computer. Based on the switching timing of the vehicle detection signal and the conductor detection signal, the determination result of the conductor length, etc., the operator determines whether the offset time is appropriate. For example, assume that the distance D3 between the specified position X2 and the conductor length determination position X3 is "-20 cm", and the offset time is set to "+v1" based on the offset amount table T1 in FIG. 8. If the operator determines that there are many errors in the determination result of the conductor length with the current offset time ("+v1"), the operator transmits an instruction (signal) to change the offset time via the maintenance computer. For example, when the operator designates another offset time "+v2", the conductor detector 20 (offset processing unit 212) performs offset processing using the designated offset time "+v2" in subsequent processing. Thereby, the conductor detector 20 can improve the determination accuracy.

[0086] <Supplementary Note> The conductor detector, conductor detection method, and program described in the above embodiment are understood as follows, for example.

[0087] According to a first aspect of the present disclosure, a vehicle length detector (20) is a vehicle length detector (20) that detects the vehicle length of a vehicle traveling in a lane, and is based on a vehicle detection signal indicating whether the vehicle exists at an entry detection position of the lane, a first time acquisition unit that acquires a first time indicating a time when the vehicle has passed the entry detection position; a second time acquisition unit that acquires a second time indicating a time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at a vehicle length determination position on the downstream side in the vehicle traveling direction from the entry detection position; an offset processing unit that offsets the second time by a predetermined offset amount according to the installation environment of the vehicle length detector; and a determination unit that determines that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time.

[0088] According to a second aspect of the present disclosure, in the vehicle length detector (20) according to the first aspect, when the distance from the entry detection position to the vehicle length determination position is shorter than the threshold value, the offset processing unit offsets the second time so as to delay it by a predetermined time.

[0089] According to a third aspect of the present disclosure, in the vehicle length detector (20) according to the first or second aspect, when the distance from the entry detection position to the vehicle length determination position is longer than the threshold value, the offset processing unit offsets the second time so as to advance it by a predetermined time.

[0090] According to a fourth aspect of the present disclosure, in the vehicle length detector (20) according to any one of the first to third aspects, when the vehicle length detector is installed in the installation environment in which the vehicle having a load protruding in the longitudinal direction of the vehicle body travels, the offset processing unit offsets the second time so as to delay it by a predetermined time.

[0091] According to a fifth aspect of the present disclosure, in the vehicle length detector (20) according to any one of the second to fourth aspects, the offset processing unit changes the offset amount according to the assumed speed of the vehicle.

[0092] According to a sixth aspect of the present disclosure, in the vehicle length detector (20) according to the 51st aspect, the offset processing unit determines the assumed speed based on statistical information on the speeds of a plurality of the vehicles traveling in the lane.

[0093] According to a seventh aspect of the present disclosure, a vehicle length detection method is a vehicle length detection method for detecting the vehicle length of a vehicle traveling in a lane by a vehicle length detector (20), the method including: obtaining a first time indicating a time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; obtaining a second time indicating a time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position; offsetting the second time by an offset amount according to the installation environment of the vehicle length detector; and determining that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time.

[0094] According to an eighth aspect of the present disclosure, a program causes a vehicle length detector (20) for detecting the vehicle length of a vehicle traveling in a lane to execute: obtaining a first time indicating a time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; obtaining a second time indicating a time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position; offsetting the second time by an offset amount according to the installation environment of the vehicle length detector; and determining that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time.

Explanation of Reference Numerals

[0095] 1 Vehicle length detection system 10 Vehicle detector 11 Light projector 12 Light receiver 20 Vehicle length detector 21 Processor 210 First Time Acquisition Unit 211 Second Time Acquisition Unit 212 Offset Processing Unit 213 Determination Unit 22 Memory 23 Storage 24 Communication Interface 25 Light Emitter 26 Light Receiver

Claims

1. A vehicle length detector for detecting the vehicle length of a vehicle traveling in a lane, a first time acquisition unit that acquires a first time indicating the time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; a second time acquisition unit that acquires a second time indicating the time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position; an offset processing unit that offsets the second time by an offset amount corresponding to the installation environment of the vehicle length detector; a determination unit that determines that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time; comprising: when the distance from the entry detection position to the vehicle length determination position is shorter than the threshold value, the offset processing unit offsets the second time so as to delay it by a predetermined time; a vehicle length detector.

2. A vehicle length detector for detecting the vehicle length of a vehicle traveling in a lane, a first time acquisition unit that acquires a first time indicating the time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; a second time acquisition unit that acquires a second time indicating the time when the vehicle has reached the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at the vehicle length determination position on the downstream side of the vehicle traveling direction from the entry detection position; an offset processing unit that offsets the second time by an offset amount corresponding to the installation environment of the vehicle length detector; a determination unit that determines that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time; comprising: when the distance from the entry detection position to the vehicle length determination position is longer than the threshold value, the offset processing unit offsets the second time so as to advance it by a predetermined time; a vehicle length detector.

3. A vehicle length detector for detecting the vehicle length of a vehicle traveling in a lane, a first time acquisition unit that acquires a first time indicating the time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; A second time acquisition unit that acquires a second time indicating the time when the vehicle reaches the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at a vehicle length determination position on the downstream side of the entry detection position in the vehicle traveling direction; An offset processing unit that offsets the second time by an offset amount corresponding to the installation environment of the vehicle length detector; A determination unit that determines that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time; Comprising; When the vehicle length detector is installed in the installation environment where the vehicle having a load protruding in the longitudinal direction of the vehicle body travels, the offset processing unit offsets the second time so as to delay it by a predetermined time. Vehicle length detector.

4. The offset processing unit changes the offset amount according to the assumed speed of the vehicle. The vehicle length detector according to any one of claims 1 to 3.

5. The offset processing unit determines the assumed speed based on statistical information of the speeds of a plurality of the vehicles traveling in the lane. The vehicle length detector according to claim 4.

6. A vehicle length detection method for detecting the vehicle length of a vehicle traveling in a lane by a vehicle length detector, Obtaining a first time indicating the time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; Obtaining a second time indicating the time when the vehicle reaches the vehicle length determination position based on a vehicle length detection signal indicating whether the vehicle exists at a vehicle length determination position on the downstream side of the entry detection position in the vehicle traveling direction; Offsetting the second time by an offset amount corresponding to the installation environment of the vehicle length detector; Determining that the vehicle length of the vehicle is equal to or greater than a threshold value when the offset second time is earlier than the first time; Having; In the step of offsetting the second time, when the distance from the entry detection position to the vehicle length determination position is shorter than the threshold value, the second time is offset so as to be delayed by a predetermined time. Vehicle length detection method.

7. In a vehicle length detector for detecting the vehicle length of a vehicle traveling in a lane, Obtaining a first time indicating the time when the vehicle has passed the entry detection position based on a vehicle detection signal indicating whether the vehicle exists at the entry detection position of the lane; Based on a vehicle length detection signal indicating whether the vehicle exists at a vehicle length determination position downstream of the entry detection position in the vehicle traveling direction, obtaining a second time indicating the time when the vehicle reaches the vehicle length determination position; Offsetting the second time by an offset amount according to the installation environment of the vehicle length detector; When the second time after offsetting is earlier than the first time, determining that the vehicle length of the vehicle is equal to or greater than a threshold; A program for causing the above to be executed, In the step of offsetting the second time, when the distance from the entry detection position to the vehicle length determination position is shorter than the threshold, offsetting the second time to be delayed by a predetermined time; Program.

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