Forward / reverse determination device, forward / reverse determination method and forward / reverse determination program

Abstract

To provide a method that determines whether a vehicle moves forward or backward without using a plurality of vehicle detectors.SOLUTION: A forward / reverse determination device 10 acquires an ON-time result indicating whether a license plate is detected from image data obtained at an ON timing, at which a detection state by a vehicle detector 2 changes from an OFF state to an ON state. The forward / reverse determination device 10 acquires an OFF-time result indicating whether the license plate is detected from image data obtained at an OFF timing, at which the detection state by the vehicle detector 2 changes from the ON state to the OFF state. The forward / reverse determination device 10 determines whether the vehicle moves forward or backward based on a combination of the ON-time result and the OFF-time result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a technique for determining whether a vehicle is moving forward or backward. [Background technology]

[0002] The electronic toll collection system constantly monitors the number of vehicles in a traffic lane and checks the number of vehicles that have already been charged to ensure that no charges have been missed. Currently, two vehicle detectors, which are sensors that detect vehicles, are installed near the entrance to the traffic lane. The order in which the two vehicle detectors detect vehicles determines whether the vehicle is moving forward or backward. Whether the vehicle is moving forward or backward determines whether the vehicle has entered or exited the traffic lane. This allows the number of vehicles in the traffic lane to be identified. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-002212 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a single vehicle detector to reduce costs, etc. However, if only one vehicle detector is used, the current method of determining whether a vehicle is moving forward or backward will no longer be usable. If it is not possible to determine whether a vehicle is moving forward or backward, it will be impossible to determine the number of vehicles in a traffic lane. As a result, it will no longer be possible to properly check whether or not a toll has been missed, which is an important issue in an electronic toll collection system. An object of the present disclosure is to make it possible to determine whether a vehicle is moving forward or backward without using multiple vehicle detectors. [Means for solving the problem]

[0005] The forward / reverse movement determination device according to the present disclosure comprises: a detection result acquisition unit that acquires an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state where no detection is made to an ON state where detection is made, and also acquires an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state; a forward / reverse determination unit that determines whether the vehicle is moving forward or backward based on a combination of the ON-state result and the OFF-state result acquired by the detection result acquisition unit; Equipped with. [Effects of the Invention]

[0006] In the present disclosure, whether a vehicle is moving forward or backward is determined based on a combination of whether a license plate is detected at the ON timing and whether a license plate is detected at the OFF timing. This makes it possible to determine whether a vehicle is moving forward or backward even when using only one vehicle detector. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a configuration diagram of an electronic toll collection system 1 according to a first embodiment. [Figure 2] 1 is a configuration diagram of a forward / reverse movement determination device 10 according to a first embodiment. [Figure 3] 3 is a flowchart showing the operation of the forward / reverse movement determination device 10 according to the first embodiment. [Figure 4] FIG. 2 is an explanatory diagram of a photographing area according to the first embodiment. [Figure 5] FIG. 4 is an explanatory diagram of a combination of an ON-time result and an OFF-time result according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Embodiment 1 ***Configuration Description*** The configuration of an electronic toll collection system 1 according to the first embodiment will be described with reference to FIG. The electronic toll collection system 1 includes devices such as a vehicle detector 2, a camera 3, a roadside antenna 4, an NP device 5, and a forward / reverse determination device 10. The vehicle detector 2 is composed of a pair of devices installed on both sides of the traffic lane 6 near the entrance to the traffic lane 6. The vehicle detector 2 detects vehicles present in a detection area 7 between the pair of devices. The camera 3 is installed to capture an image of the shooting area in the traffic lane 6 from ahead in the direction of travel of the vehicle. The shooting area is set around the detection area 7. The camera 3 is used to recognize the license plate numbers of vehicles present in the traffic lane 6. The roadside antenna 4 is used to communicate with an onboard device installed in the vehicle and collect tolls. The NP device 5 is a computer that detects the vehicle's license plate from the image data obtained by the camera 3 and recognizes the number. The forward / reverse travel determination device 10 is a computer that determines whether the vehicle is traveling forward or backward based on the detection results of the NP device 5.

[0009] The configuration of the forward / reverse movement determination device 10 according to the first embodiment will be described with reference to FIG. The forward / reverse determination device 10 is a computer. The forward / reverse determination device 10 includes hardware such as a processor 11, a memory 12, a storage 13, and a communication interface 14. The processor 11 is connected to other hardware via signal lines and controls the other hardware.

[0010] The processor 11 is an IC that performs processing. IC stands for Integrated Circuit. Specific examples of the processor 11 include a CPU, a DSP, and a GPU. CPU stands for Central Processing Unit. DSP stands for Digital Signal Processor. GPU stands for Graphics Processing Unit.

[0011] The memory 12 is a storage device that temporarily stores data. Specific examples of the memory 12 include SRAM and DRAM. SRAM stands for Static Random Access Memory. DRAM stands for Dynamic Random Access Memory.

[0012] The storage 13 is a storage device that stores data. A specific example of the storage 13 is an HDD. HDD is an abbreviation for Hard Disk Drive. The storage 13 may also be a portable recording medium such as an SD (registered trademark) memory card, CompactFlash (registered trademark), NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD. SD is an abbreviation for Secure Digital. DVD is an abbreviation for Digital Versatile Disk.

[0013] The communication interface 14 is an interface for communicating with external devices. Specific examples of the communication interface 14 include Ethernet (registered trademark), USB, and HDMI (registered trademark) ports. USB stands for Universal Serial Bus. HDMI stands for High-Definition Multimedia Interface.

[0014] The forward / reverse determination device 10 includes, as functional components, a detection result acquisition unit 21, a forward / reverse determination unit 22, and a vehicle number determination unit 23. The functions of the functional components of the forward / reverse determination device 10 are realized by software. The storage 13 stores a program that realizes the function of each functional component of the forward / reverse movement determination device 10. This program is read into the memory 12 by the processor 11 and executed by the processor 11. In this way, the function of each functional component of the forward / reverse movement determination device 10 is realized.

[0015] 1 shows only one processor 11. However, there may be a plurality of processors 11, and the plurality of processors 11 may cooperate to execute programs that realize the respective functions.

[0016] ***Explanation of Operation*** The operation of the forward / reverse movement determining device 10 according to the first embodiment will be described with reference to FIGS. The operation procedure of the forward / reverse movement determination device 10 according to the embodiment 1 corresponds to the forward / reverse movement determination method according to the embodiment 1. Moreover, the program that realizes the operation of the forward / reverse movement determination device 10 according to the embodiment 1 corresponds to the forward / reverse movement determination program according to the embodiment 1.

[0017] (Step S1 in Figure 3: ON result acquisition process) The detection result acquisition unit 21 acquires an ON result indicating whether or not a vehicle license plate has been detected from image data obtained by photographing the photographing area at the ON timing. The ON timing is the timing when the detection state of the vehicle detector 2 changes from an OFF state, in which no detection is made, to an ON state, in which detection is made. Specifically, a vehicle enters the detection area 7 of the vehicle detector 2. Then, the vehicle detector 2 detects the vehicle that has entered the detection area 7. This causes the ON timing, which changes from the OFF state to the ON state. The NP device 5 then detects the vehicle's license plate from the image data obtained by photographing the photographing area with the camera 3. The detection of the license plate means that the number printed on the license plate has been recognized. The detection result acquisition unit 21 acquires an ON result, which is a detection result indicating whether or not the license plate has been detected by the NP device 5. Here, cases in which a vehicle enters the detection area 7 of the vehicle detector 2 include a case in which the vehicle enters the detection area 7 by moving forward, and a case in which the vehicle enters the detection area 7 by moving backward.

[0018] (Step S2 in Figure 3: OFF result acquisition process) The detection result acquisition unit 21 acquires an OFF result indicating whether or not a vehicle license plate has been detected from image data obtained by photographing the photographing area at the OFF timing. The OFF timing is the timing at which the detection state of the vehicle detector changes from an ON state in which detection is performed to an OFF state in which detection is not performed. Specifically, a vehicle exits the detection area 7 of the vehicle detector 2. Then, the vehicle detector 2 stops detecting the vehicle that has exited the detection area 7. This causes the OFF timing, when the state changes from ON to OFF. The NP device 5 then detects the vehicle's license plate from the image data obtained by the camera 3 capturing an image of the capture area. The detection result acquisition unit 21 acquires an OFF result, which is a detection result indicating whether or not the license plate has been detected by the NP device 5. Here, cases in which a vehicle leaves the detection area 7 of the vehicle detector 2 include a case in which the vehicle leaves the detection area 7 by moving forward, and a case in which the vehicle leaves the detection area 7 by moving backward.

[0019] (Step S3 in Figure 3: forward / reverse determination process) The forward / reverse determination unit 22 determines whether the vehicle is moving forward or backward based on a combination of the ON result acquired in step S1 and the OFF result acquired in step S2.

[0020] This will be described in detail with reference to FIGS. As shown in Fig. 4, only the area near the detection area 7 is set as the photography area. Therefore, the license plates of vehicles that have advanced into the detection area 7 and vehicles that have reversed out of the detection area 7 are included in the photography area. However, the license plates of vehicles that have advanced out of the detection area 7 and vehicles that have reversed into the detection area 7 are not included in the photography area.

[0021] As shown in FIG. 5, there are four patterns of entry and exit into the detection area 7, Pattern 1 to Pattern 4, as follows. Pattern 1: Enter by moving forward, then exit by moving forward. Pattern 2: Enter by moving backward, then exit by moving backward. Pattern 3: Enter by moving forward, then exit by moving backward. Pattern 4: Enter by moving backward, then exit by moving forward. Each pattern has a different combination of ON results and OFF results. Therefore, the forward / reverse determination unit 22 can determine which pattern it is based on the combination of the ON-time result and the OFF-time result. For example, when the result when ON indicates that a license plate has been detected, and when the result when OFF indicates that a license plate has not been detected, the forward / reverse determination unit 22 determines that the vehicle has moved forward, entered traffic lane 6, and moved forward, and exited traffic lane 6.

[0022] As shown in FIG. 5, when determining whether the vehicle was moving forward or backward when the power was off, only the results when the power was off can be determined.

[0023] (Step S4 in FIG. 3: Number Identification Processing) The vehicle number determination unit 23 determines the number of vehicles that have entered the traffic lane 6 based on whether it is determined in step S2 that the target vehicle is moving forward or backward. In case of pattern 1, when the target vehicle enters by moving forward and then exits by moving forward, the target vehicle becomes a vehicle that has newly entered traffic lane 6. Therefore, 1 is added to the number of vehicles that have entered traffic lane 6. In contrast, in case of pattern 2, when the target vehicle enters by moving backward and then exits by moving backward, the target vehicle becomes a vehicle that has exited traffic lane 6. Therefore, 1 is subtracted from the number of vehicles that have entered traffic lane 6. In the case of patterns 3 and 4, the number of vehicles entering traffic lane 6 remains unchanged, so there is no need to increase or decrease the number of vehicles.

[0024] ***Effects of the First Embodiment*** As described above, the forward / reverse movement determination device 10 according to the first embodiment determines whether the vehicle is moving forward or backward based on a combination of whether or not the license plate is detected at the ON timing and whether or not the license plate is detected at the OFF timing. This makes it possible to determine whether the vehicle is moving forward or backward even when only one vehicle detector is used.

[0025] ***Other Configurations*** <Variation 1> In the first embodiment, each functional component is realized by software. However, as a first modification, each functional component may be realized by hardware. The differences between the first embodiment and the first modification will be described below.

[0026] When each functional component is realized by hardware, the forward / reverse movement determination device 10 includes an electronic circuit 15 instead of the processor 11, memory 12, and storage 13. The electronic circuit 15 is a dedicated circuit that realizes the functions of each functional component, the memory 12, and the storage 13.

[0027] The electronic circuit 15 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, or an FPGA. GA stands for Gate Array. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field-Programmable Gate Array. Each functional component may be realized by one electronic circuit 15, or each functional component may be realized by distributing it among a plurality of electronic circuits 15.

[0028] <Variation 2> As a second modification, some of the functional components may be realized by hardware, and other functional components may be realized by software.

[0029] The processor 11, memory 12, storage 13, and electronic circuit 15 are collectively referred to as a processing circuit. In other words, the functions of the respective functional components are realized by the processing circuit.

[0030] Furthermore, the term "unit" in the above description may be read as a "circuit," "step," "procedure," "process," or "processing circuit."

[0031] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) a detection result acquisition unit that acquires an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state where no detection is made to an ON state where detection is made, and also acquires an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state; a forward / reverse determination unit that determines whether the vehicle is moving forward or backward based on a combination of the ON-state result and the OFF-state result acquired by the detection result acquisition unit; A forward / reverse determination device comprising: (Appendix 2) The photographing area is set to include the license plates of vehicles that have advanced into the detection area and vehicles that have reversed out of the detection area, but not to include the license plates of vehicles that have advanced out of the detection area and vehicles that have reversed into the detection area. 2. The forward / reverse movement determination device according to claim 1. (Appendix 3) The forward / reverse determination unit determines that the vehicle has moved forward to enter the traffic lane and moved forward to exit the traffic lane when the ON result indicates that a license plate has been detected and when the OFF result indicates that a license plate has not been detected. 3. The forward / reverse movement determination device according to claim 2. (Appendix 4) The forward / reverse movement determination device further includes: a number determination unit that determines the number of vehicles that have entered the traffic lane using the result of the determination by the forward / reverse determination unit; 4. The forward / reverse movement determination device according to claim 1, further comprising: (Appendix 5) The traffic lane is a lane where an electronic toll collection system is installed. 5. The forward / reverse movement determination device according to any one of appendices 1 to 4. (Appendix 6) The computer acquires an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state in which the vehicle is not detecting to an ON state in which the vehicle is detecting, and also acquires an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state, A forward / reverse determination method in which a computer determines whether the vehicle is moving forward or backward based on a combination of the ON-time result and the OFF-time result. (Appendix 7) a detection result acquisition process for acquiring an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state where no detection is made to an ON state where detection is made, and acquiring an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state; a forward / reverse determination process for determining whether the vehicle is moving forward or backward based on a combination of the ON-state result and the OFF-state result acquired by the detection result acquisition process; A forward / reverse determination program that causes a computer to function as a forward / reverse determination device that performs the above.

[0032] The embodiments and modifications of the present disclosure have been described above. Some of these embodiments and modifications may be combined and implemented. Also, one or more of them may be implemented partially. Note that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible as needed. [Explanation of symbols]

[0033] 1 Electronic toll collection system, 2 Vehicle detector, 3 Camera, 4 Roadside antenna, 5 NP device, 6 Traffic lane, 7 Detection area, 10 Forward / reverse determination device, 11 Processor, 12 Memory, 13 Storage, 14 Communication interface, 21 Detection result acquisition unit, 22 Forward / reverse determination unit, 23 Vehicle number identification unit.

Claims

1. a detection result acquisition unit that acquires an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing an imaging area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state in which the vehicle is not detecting to an ON state in which the vehicle is detecting, and that acquires an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the imaging area at an OFF timing when the detection state changes from the ON state to the OFF state; a forward / reverse determination unit that determines whether the vehicle is moving forward or backward based on a combination of the ON-time result and the OFF-time result acquired by the detection result acquisition unit; A forward / reverse determination device comprising:

2. The photographing area is set to include the license plates of vehicles that have advanced into the detection area and vehicles that have reversed out of the detection area, but not to include the license plates of vehicles that have advanced out of the detection area and vehicles that have reversed into the detection area. The forward / reverse movement determination device according to claim 1 .

3. The forward / reverse determination unit determines that the vehicle has moved forward to enter the traffic lane and moved forward to exit the traffic lane when the ON result indicates that a license plate has been detected and when the OFF result indicates that a license plate has not been detected. The forward / reverse movement determination device according to claim 2.

4. The forward / reverse movement determination device further includes: a number determination unit that determines the number of vehicles that have entered the traffic lane using the result of the determination by the forward / reverse determination unit; The forward / reverse movement determination device according to claim 1 , comprising:

5. The traffic lane is a lane where an electronic toll collection system is installed. The forward / reverse movement determination device according to claim 1 .

6. The computer acquires an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state in which the vehicle is not detecting to an ON state in which the vehicle is detecting, and acquires an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state, A forward / reverse determination method in which a computer determines whether the vehicle is moving forward or backward from a combination of the ON-time result and the OFF-time result.

7. a detection result acquisition process for acquiring an ON result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an ON timing when the detection state of a vehicle detector that detects a vehicle present in a detection area in a traffic lane changes from an OFF state in which the vehicle is not detecting to an ON state in which the vehicle is detecting, and acquiring an OFF result indicating whether or not the license plate of the vehicle has been detected from image data obtained by photographing the photographing area at an OFF timing when the detection state changes from the ON state to the OFF state; a forward / reverse travel determination process for determining whether the vehicle is traveling forward or backward based on a combination of the ON-time result and the OFF-time result acquired by the detection result acquisition process; A forward / reverse determination program that causes a computer to function as a forward / reverse determination device that performs the above.

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