Traffic signal control device, traffic signal control method, and traffic signal control system

Abstract

To improve a technique for traffic light control at crosswalks.SOLUTION: A traffic light control device includes a communication unit and a control unit. The communication unit acquires detection results obtained by detecting moving bodies for a plurality of areas to be detected around crosswalks including the crosswalks. The control unit recognizes a combination of presence / absence of moving bodies for each area included in the plurality of areas based on the detection results acquired by the communication unit, and controls pedestrian traffic lights and vehicle traffic lights based on the combination.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a traffic signal control device, a traffic signal control method, and a traffic signal control system.

Background Art

[0002] Conventionally, a crosswalk signal system has been proposed that detects waiting pedestrians waiting to cross a crosswalk and controls pedestrian traffic signals and vehicle traffic signals by recall control based on the detection of waiting pedestrians (see, for example, Patent Document 1). According to Patent Document 1, an image including pedestrians standing in front of a crosswalk is captured by an imaging device, and by performing predetermined image analysis on the captured image, it is determined whether the pedestrians are waiting pedestrians attempting to cross the crosswalk. This image analysis includes processes such as extracting a person shown in an image portion corresponding to a waiting area in the captured image, tracking the extracted person, and determining the line-of-sight direction of the extracted person.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional method for controlling traffic signals at crosswalks, since the intention of pedestrians to cross is predicted by performing complex image processing, there may be fluctuations in the determination. Also, depending on conditions such as weather and brightness, it may become difficult to determine the line-of-sight direction of pedestrians. That is, in the conventional technology, since advanced image recognition is required, there is concern that the robustness of image recognition becomes insufficient and problems occur in stable operation.

[0005] In view of such circumstances, an object of the present disclosure is to improve the technology of traffic signal control at crosswalks. [Means for solving the problem]

[0006] A traffic signal control device according to one embodiment of the present disclosure includes a communication unit that acquires detection results of detecting a moving object in a plurality of detection target areas around a crosswalk, including the crosswalk, and a control unit that recognizes the presence or absence of the moving object in each of the plurality of areas based on the detection results acquired by the communication unit, and controls a pedestrian signal and a vehicle signal based on the combination.

[0007] Furthermore, a traffic signal control method according to one embodiment of the present disclosure is a traffic signal control method executed by a control unit of a traffic signal control device, which includes: obtaining detection results of detecting a moving body in a plurality of detection target areas around a crosswalk, including the crosswalk; recognizing combinations of the presence or absence of the moving body in each of the plurality of areas based on the detection results; and controlling pedestrian signals and vehicle signals based on the combinations.

[0008] Furthermore, a traffic signal control system according to one embodiment of the present disclosure includes a pedestrian signal and a vehicle signal positioned to control traffic on a crosswalk, a detector that detects moving objects in a plurality of detection target areas around the crosswalk, including the crosswalk, a communication unit that acquires detection results of the detection of moving objects from the detector, and a traffic signal control device that recognizes combinations of the presence or absence of the moving object in each of the plurality of areas based on the detection results, and controls the pedestrian signal and the vehicle signal based on the combination. [Effects of the Invention]

[0009] According to this disclosure, it is possible to improve the technology for controlling traffic signals at pedestrian crossings. [Brief explanation of the drawing]

[0010] [Figure 1]This block diagram shows a schematic configuration of a traffic signal control system according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a plan view illustrating an example of the arrangement of each component and the detection area of ​​a traffic signal control system. [Figure 3] This figure shows an example of a signal indication hierarchy diagram for pedestrian and vehicle traffic signals in Figure 1. [Figure 4] This flowchart shows an example of traffic signal control processing by a traffic signal control device. [Figure 5] Figure 4 is a flowchart showing an example of the process for determining whether to switch traffic signals. [Figure 6] This figure shows an example of the transition condition from the first state to the second state. [Figure 7] This figure shows an example of the transition condition from the second state to the first state. [Modes for carrying out the invention]

[0011] An embodiment of this disclosure will be described below with reference to the drawings. Note that the figures used in the following description are schematic. Dimensions and proportions shown in the drawings do not necessarily correspond to actual dimensions.

[0012] (Configuration of the traffic signal control system) A traffic signal control system 1 according to one embodiment of the present disclosure includes, as shown in Figure 1, a traffic signal control device 10, one or more detectors 20, a pedestrian signal 31, and a vehicle signal 32. The traffic signal control device 10, the detectors 20, the pedestrian signal 31, and the vehicle signal 32 are each communicated with by wired communication means and / or wireless communication means.

[0013] The traffic signal control device 10 is a computer that controls the pedestrian signal 31 and the vehicle signal 32. The traffic signal control device 10 may be located adjacent to the pedestrian signal 31 and the vehicle signal 32. At least some of the functions of the traffic signal control device 10 may be located in a remote location away from the pedestrian signal 31 and the vehicle signal 32. The traffic signal control device 10 includes a communication unit 11, a control unit 12, and a storage unit 13.

[0014] The communication unit 11 includes a communication interface for communicating with external devices of the signal control device 10. The external devices include a detector 20, a pedestrian signal 31, and a vehicle signal 32. The communication unit 11 supports wired communication and / or wireless communication.

[0015] The control unit 12 comprises one or more processors and memory. The processors include a general-purpose processor that executes programmed functions by loading a specific program, and a dedicated processor specialized for specific processing. The control unit 12 loads a program for traffic signal control and controls the pedestrian signal 31 and the vehicle signal 32. The control unit 12 performs various calculations to control the pedestrian signal 31 and the vehicle signal 32.

[0016] The storage unit 13 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or at least two combinations thereof. The storage unit 13 functions, for example, as a main memory, auxiliary memory, or cache memory. The storage unit 13 stores programs and data used for the operation of the signal control device 10, and data obtained by the operation of the signal control device 10. The information stored in the storage unit 13 may be updateable with information obtained, for example, from the communication unit 11.

[0017] The signal control device 10 may include an input unit, a display unit, etc. in addition to the communication unit 11, the control unit 12, and the storage unit 13. The input unit includes button switches, touch panels, etc. for the administrator of the signal control system 1 to directly perform operations. The display unit includes a display such as an LCD (liquid crystal display) for performing displays according to the administrator's operations.

[0018] The detector 20 is a sensor that detects moving objects in the peripheral area of the crosswalk 41 including the crosswalk 41 (see FIG. 2). In the present disclosure, a moving object means a person and an object that can move. A moving object may stop at a certain moment. The moving object may include a plurality of types of people or objects such as pedestrians 42, vehicles 43, bicycles, and personal mobility vehicles (PMVs: Personal Mobility Vehicles). A moving object can be paraphrased as a traffic participant. The detector 20 does not have to discriminate the type of the moving object. Since the detector 20 detects moving objects in a predetermined peripheral area, two or more detectors 20 may be arranged. The detector 20 is configured to transmit the detection result to the signal control device 10. The detection result of the detector 20 is used to recognize the presence or absence of moving objects in each of a plurality of areas included in the peripheral area of the crosswalk 41 including the crosswalk 41.

[0019] The detector 20 is, for example, a camera fixed to a structure such as a signal or a utility pole adjacent to the crosswalk 41 and imaging the peripheral area of the crosswalk 41. The camera is not limited to a camera that images visible light images and may include an infrared camera that images light with an infrared wavelength. When the detector 20 is a camera, in the present disclosure, "detecting a moving object" is used in the sense of both simply imaging an image including the moving object and identifying the moving object from the imaged image.

[0020] As the detector 20, for example, an edge AI (artificial intelligence) camera can be used. The edge AI camera is a camera equipped with an AI processing function. The edge AI camera can perform AI processing on an image captured inside the camera and transmit the processing result to the traffic signal control device 10. The edge AI camera can identify a moving object from the captured image and transmit the information of the identified moving object together with the captured image to the traffic signal control device 10.

[0021] The detector 20 may be a general camera instead of an edge AI camera. In this case, the detector 20 may transmit the captured image as a detection result to the traffic signal control device 10. The detection of moving objects for each area from the captured image is performed by the control unit 12. In this case, the control unit 12 may have a function of executing AI image analysis processing.

[0022] The detector 20 is not limited to a camera. The detector 20 may be any sensor that can be used to detect the presence or absence of a moving object within a specific area. The detector 20 may include, for example, an ultrasonic sensor fixed to a structure on the pedestrian road 44 and / or the vehicle road 45, and / or an infrared sensor. Also, the detector 20 may be a sensor buried in the vehicle road 45 such as a loop coil detector. The detector 20 may arrange these sensors at the end of a specific area to detect the presence or absence of a moving object entering or leaving the specific area.

[0023] The pedestrian traffic signal 31 and the vehicle traffic signal 32 are arranged to control the passage of the crosswalk 41.

[0024] The pedestrian traffic signals 31 are positioned on both sides of the road for vehicles 45, flanking the crosswalk 41. The pedestrian traffic signals 31 are positioned with their light-emitting parts facing pedestrians 42 crossing the crosswalk 41. The pedestrian traffic signals 31 provide pedestrians 42 with indications that the crosswalk 41 is passable or not passable. For example, the pedestrian traffic signals 31 include a blue light-emitting part and a red light-emitting part. When the blue light-emitting part is lit, it indicates that pedestrians 42 are allowed to pass. When the red light-emitting part is lit, it indicates that pedestrians 42 are not allowed to pass. In addition, before the signal switches from being lit by the blue light-emitting part to being lit by the red light-emitting part, the blue light-emitting part flashes to indicate that the signal change is imminent. The pedestrian traffic signals 31 are controlled by the traffic signal control device 10.

[0025] The vehicle traffic signal 32 is positioned to face drivers of vehicles 43 on the road 45, with the pedestrian crossing 41 in between. The vehicle traffic signal 32 indicates to drivers of vehicles 43 whether they are permitted or prohibited from crossing the pedestrian crossing 41. For example, the vehicle traffic signal 32 has blue, red, and yellow light-emitting parts. The blue light-emitting part indicates that vehicles 43 are permitted to cross the pedestrian crossing 41. The red light-emitting part indicates that vehicles 43 are prohibited from crossing the pedestrian crossing 41. In addition, the blue signal changes to red after passing through a yellow signal. The vehicle traffic signal 32 is controlled by a traffic signal control device 10.

[0026] Pedestrian traffic signals 31 and vehicle traffic signals 32 are not limited to indicating passable or impassable by the color of the light-emitting part as described above. For example, to indicate that it is passable, pedestrian traffic signals 31 and / or vehicle traffic signals 32 may display an arrow. Also, the color of the light-emitting part indicating that it is passable may be green instead of blue. In the following explanation, for the sake of simplicity, the colors displayed by the traffic signals, such as blue, red, and yellow, may be used to describe the states indicated by the traffic signals.

[0027] (Examples of area and equipment placement around pedestrian crossings) Figure 2 shows an example of the arrangement of a pedestrian crossing 41 at the intersection of a pedestrian road 44 and a vehicle road 45, multiple detection target areas, and each component of the traffic signal control system 1.

[0028] Pedestrian walkway 44 is a road used by pedestrians 42, as well as bicycles and PMVs. Pedestrians 42, bicycles, and PMVs are included in the category of moving objects. Moving objects traveling on pedestrian walkway 44 use the crosswalk 41 in accordance with the pedestrian signal 31. Since the signal control system 1 does not identify the type of moving object, moving objects traveling on pedestrian walkway 44 are treated as pedestrians 42 in practice.

[0029] The vehicle road 45 is a road used by vehicles 43, as well as bicycles and PMVs. Vehicles 43, bicycles, and PMVs are included in the category of mobile bodies. Mobile bodies traveling on the vehicle road 45 travel on the vehicle road 45 in accordance with the vehicle traffic signals 32. Since the traffic signal control system 1 does not identify the type of mobile body, mobile bodies traveling on the vehicle road 45 are treated as vehicles 43 in effect.

[0030] The detection area for the pedestrian crossing 41 and its surroundings includes, for example, a first area 51, a second area 52, and a third area 53. The first area 51 is the area on the pedestrian crossing 41. The second area 52 is the area where pedestrians 42 pass near the pedestrian crossing 41. The third area 53 is the area where vehicles 43 approaching the pedestrian crossing 41 pass. The third area 53 may be the area on the lane of the road 45 leading to the pedestrian crossing 41, from a predetermined distance before the pedestrian crossing 41 to immediately before the pedestrian crossing 41. The predetermined distance can be arbitrarily set according to the road environment, for example, 30m, 50m, or 100m. Hereinafter, the first area 51, the second area 52, and the third area 53 may also be referred to as the crossing area, the pedestrian-side vicinity area, and the vehicle approach area, respectively. There is one second area 52 on each side of the road 45. The third area 53 exists on both the left and right sides of the center line 46 of the road for vehicles 45.

[0031] The second area 52 may further include the fourth area 54 and the fifth area 55. The fourth area 54 is adjacent to the pedestrian crossing 41 and is the area where pedestrians 42 wait for the traffic light. The fifth area 55 is adjacent to the fourth area 54 and is located further away from the pedestrian crossing 41 than the fourth area 54, and is the area through which pedestrians 42 pass when heading towards the pedestrian crossing 41. The depths of the fourth area 54 and the fifth area 55 can be arbitrarily set according to the road environment, etc. For example, the fourth area 54 may be an area on the pedestrian road 44 with a width 1m to 2m wider than the width of the pedestrian crossing 41 and a depth of 2m, 3m, or 5m. The fifth area 55 may be an area on the pedestrian road 44 with a depth of 10m, 20m, or 30m. Here, depth means the length in the direction in which the pedestrian road 44 extends. In the following, the fourth area 54 and the fifth area 55 may also be referred to as the pedestrian crossing waiting area and the pedestrian crossing approach area, respectively.

[0032] In the example shown in Figure 2, two detectors 20A and 20B are provided as detectors 20, one on each side of the road with the pedestrian crossing 41 in between. In one embodiment, detectors 20A and 20B may each be equipped with one or more edge AI cameras. For example, detector 20A may be configured to image a first region 51 and a second region 52 and a third region 53 located on the detector 20A side (left side in Figure 2) of the center line 46 of the roadway 45. Detector 20B may be configured to image a first region 51 and a second region 52 and a third region 53 located on the detector 20B side (right side in Figure 2) of the center line 46 of the roadway 45.

[0033] The edge AI cameras, detectors 20A and 20B, each detect whether or not a moving object is present in the area they are to detect. Detectors 20A and 20B only need to detect the presence or absence of a moving object and its location (area); they do not need to analyze the type, orientation, direction of travel, or speed of the moving object. Therefore, detectors 20A and 20B do not need to perform complex image processing. The number of detectors 20 is not limited to two. Detectors 20 may include a sufficient number of edge AI cameras to encompass the area to be imaged, from the first area 51 to the fifth area 55 around the pedestrian crossing 41. The edge AI cameras may be connected to each other via communication, and configured to integrate detection information of moving objects throughout the entire area around the pedestrian crossing 41. The information detected by detector 20A regarding the presence or absence of a moving object within the first area 51 to the fifth area 55 and its location is transmitted to the traffic signal control device 10.

[0034] The control unit 12 of the signal control device 10 integrates the detection result information obtained from each detector 20A and 20B via the communication unit 11 to determine the presence or absence of a moving object in each of the first to fifth regions 55. This presence determination is made by integrating the detection results of all detectors 20. To prevent judgment hunting (fluctuations) due to detection hunting (fluctuations), the control unit 12 determines that a moving object is present in a region when detection of a moving object continues for a certain period of time (e.g., 0.3 seconds) or longer within that region. The same applies when changing the determination of whether a moving object is present or absent.

[0035] The control unit 12 recognizes the presence or absence of moving objects in each region included in the first region 51 to the fifth region 55, i.e., the presence or absence of traffic participants such as pedestrians 42 and vehicles 43. Based on this combination, the control unit 12 determines the status of traffic participants such as pedestrians 42 and vehicles 43 in and around the crosswalk 41. For example, the control unit 12 determines the presence or absence of pedestrians 42 crossing the crosswalk 41, the presence or absence of pedestrians 42 waiting to cross the crosswalk 41, and the presence or absence of vehicles 43 approaching the crosswalk 41 or waiting for a signal before reaching the crosswalk 41. Based on the combination of the presence or absence of moving objects in each region from the first region 51 to the fifth region 55, the control unit 12 controls the pedestrian signal 31 and the vehicle signal 32.

[0036] The traffic signal control system 1 of this disclosure does not control the pedestrian signal 31 and the vehicle signal 32 by calculating the time it takes for a moving object to reach the crosswalk 41. The traffic signal control system 1 of this disclosure determines the approach of a moving object to the crosswalk 41 and its waiting state, etc., based on the arrangement and shape of each detection target area and the presence or absence of a moving object.

[0037] In one embodiment, the control unit 12 may control the pedestrian signal 31 to indicate that pedestrians 42 are permitted to pass if no moving objects are present in any of the first to third regions 51 to 53. That is, the control unit 12 may control the pedestrian signal 31 to be green as the basic state, and only change the pedestrian signal 31 to red and the vehicle signal 32 to green when predetermined transition conditions are met. In this way, it is possible to reduce the time that pedestrians 42 who have reached the crosswalk 41 have to wait for the pedestrian signal 31 to change from red to green. Furthermore, by setting the pedestrian signal 31 to be green as the basic state, it becomes unnecessary to analyze from the image of pedestrians 42 approaching the crosswalk 41 whether or not pedestrians 42 intend to pass through the crosswalk 41, at least when no moving objects are present in the third region 53.

[0038] (Signal indication hierarchy diagram) The control unit 12 controls the signal switching between the pedestrian signal 31 and the vehicle signal 32, for example, according to the signal indication hierarchy diagram in Figure 3.

[0039] Stage 1 is the stage where the pedestrian signal 31 is green and the vehicle signal 32 is red. The state of Stage 1 is the first state. Stage 1 can be the basic state of the pedestrian signal 31 and the vehicle signal 32 in the signal control system 1. The dashed arrows shown within the frame of the flowchart of the sequence from Stage 1 to Stage 3 indicate the direction of movement of the pedestrian 42, represented by "1P". When the determination conditions exemplified in Figure 6, described later, are met in Stage 1, the control unit 12 instructs a transition to Stage 2.

[0040] Stage 2 is the stage where the pedestrian signal 31 is flashing green and the vehicle signal 32 is red. The control unit 12 continues Stage 2 for a predetermined safety period of seconds before transitioning to Stage 3. In the example in Figure 3, the safety period for Stage 2 is 8 seconds.

[0041] Stage 3 is the stage where the pedestrian signal 31 and the vehicle signal 32 are red. The control unit 12 transitions to stage 4 after a predetermined safety period has elapsed in stage 3. In the example in Figure 5, the predetermined safety period is 2 seconds.

[0042] Step 4 is the step where the pedestrian signal 31 is red and the vehicle signal 32 is green. The state of Step 4 is the second state. In Step 4, pedestrians 42 are not allowed to cross the crosswalk 41. Also in Step 4, vehicles 43 are allowed to cross the crosswalk 41 on the vehicle road 45. The arrows shown as solid lines within the flowchart of the sequence from Step 4 to Step 6 indicate the direction of movement of the vehicle 43, represented by "2G". In Step 4, when the judgment conditions illustrated in Figure 7 are met, the control unit 12 instructs the transition to Step 5.

[0043] Stage 5 is the stage where the pedestrian signal 31 is red and the vehicle signal 32 is yellow. The control unit 12 continues Stage 5 for a predetermined safety period of seconds, and then transitions to Stage 6. In the example in Figure 5, the safety period for Stage 6 is 6 seconds.

[0044] Stage 6 is the stage where the pedestrian signal 31 and the vehicle signal 32 are red. The control unit 12 transitions to stage 1 after a predetermined safety period of seconds has elapsed in stage 6. In the example in Figure 5, the predetermined safety period is 2 seconds.

[0045] The safety time shown in Figure 3 is just one example. The safety time may be set to an appropriate value depending on the traffic environment and traffic volume.

[0046] As shown in Figure 3, in the traffic signal control system 1, the transition to the next stage begins when predetermined conditions are met in the first state (stage 1) and the second state (stage 4). The first state is when the pedestrian signal 31 allows pedestrians 42 to pass and the vehicle signal 32 prohibits vehicles 43 from passing. The second state is when the pedestrian signal 31 prohibits pedestrians 42 from passing and the vehicle signal 32 allows vehicles 43 to pass. Stages 2, 3, 5, and 6 transition to the next stage after a predetermined safety period of seconds has elapsed. In other words, the control unit 12 repeatedly switches the pedestrian signal 31 and the vehicle signal 32 between the first and second states. Stages 2, 3, 5, and 6 can be considered as transition states between the first and second states.

[0047] (Processing by traffic signal control device) Referring to the flowchart in Figure 4, the procedure for the signal control method performed by the signal control device 10 will be described. The method disclosed herein can be executed by a processor included in the control unit 12 according to a program. Such a program can be stored in a non-temporary computer-readable medium. Examples of non-temporary computer-readable media include, but are not limited to, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, CD-ROM (Compact Disc Read Only Memory), etc.

[0048] First, the detector 20 detects a moving object in the area to be detected. The control unit 12 of the signal control device 10 acquires the detection result detected by the detector 20 via the communication unit 11 (S11).

[0049] Next, the control unit 12 integrates the detection result information obtained from the detector 20, which is, for example, an edge AI camera, to recognize the presence or absence of a moving object in each area to be detected (S12).

[0050] The control unit 12 determines whether to switch between the pedestrian signal 31 and the vehicle signal 32 based on the combination of the presence or absence of moving objects in each area, as determined by the recognition results in S12 (S13). This switching determination involves deciding whether to transition the pedestrian signal 31 and the vehicle signal 32 between a first state and a second state, as shown in Figure 5. The signal switching determination process shown in Figure 5 will be explained below.

[0051] First, if the pedestrian signal 31 and the vehicle signal 32 are in a state transition between the first and second states (S21:Yes), the control unit 12 waits until they return to either the first or second state (S21:Yes). That is, when the control unit 12 is in the state of stages 2 and 3 of the signal indication hierarchy diagram in Figure 3, it waits until the transition to stage 4 is complete. Also, when the control unit 12 is in the state of stages 5 and 6 of the signal indication hierarchy diagram in Figure 3, it waits until the transition to stage 1 is complete.

[0052] Next, the control unit 12 determines whether the conditions for transitioning to the second state (level 4) are met if the current state of the pedestrian signal 31 and the vehicle signal 32 is the first state (level 1) (S22: Yes) (S23). The control unit 12 determines whether the combination of presence or absence of moving objects in each region, acquired from the detector 20, satisfies the conditions for transitioning to the second state shown in Figure 6.

[0053] If the conditions for transitioning to the second state are met in S23 (S23:Yes), the control unit 12 decides to perform a signal switch to the second state (S24). If the conditions for transitioning to the second state are not met in S23 (S23:No), the control unit 12 repeats the determination in S23 until the conditions for transitioning to the second state are met. As a result, when the conditions for transitioning to the second state are finally met, the control unit 12 decides to switch to the second state (S24).

[0054] Furthermore, in S22, the control unit 12 determines whether the conditions for transitioning to the first state (level 1) are met if the current state of the pedestrian signal 31 and the vehicle signal 32 is the second state (level 4) (S22: No) (S25). The control unit 12 determines whether the combination of presence or absence of moving objects in each region, acquired from the detector 20, satisfies the conditions for transitioning to the first state shown in Figure 7.

[0055] If the transition condition to the first state is met in S25 (S25:Yes), the control unit 12 decides to perform a signal switch to the first state (S26). If the transition condition to the first state is not met in S25 (S25:No), the control unit 12 repeats the determination in S25 until the transition condition to the first state is met. As a result, when the transition condition to the first state is finally met, the control unit 12 decides to switch to the first state (S26).

[0056] Returning to Figure 4, the control unit 12, based on the decision result in S13 (S24 and S26), instructs the pedestrian signal 31 and the vehicle signal 32 to switch between the first state and the second state. When switching from the first state to the second state, the control unit 12 sequentially transitions the pedestrian signal 31 and the vehicle signal 32 from step 1 to step 4 according to the signal indication step diagram in Figure 3. When switching from the second state to the first state, the control unit 12 sequentially transitions the pedestrian signal 31 and the vehicle signal 32 from step 4 to step 1 according to the signal indication step diagram in Figure 3. In this way, the control unit 12 sequentially switches the pedestrian signal 31 and the vehicle signal 32, allowing pedestrians 42 and vehicles 43 to sequentially pass through the crosswalk 41.

[0057] (Transition conditions from the first state to the second state) Next, an example of the transition condition from the first state to the second state will be explained based on Figure 6. Note that the numerical values ​​indicating time in Figure 6 are merely examples; these values ​​can be changed as appropriate.

[0058] The control unit 12 initiates the transition of the pedestrian signal 31 and the vehicle signal 32 to the second state if condition (1) described below and any one of conditions (2) to (5) are satisfied simultaneously. Condition (1) is the condition that the presence of a moving object in the third area 53 (vehicle approach area) continues for 1 second or more. That is, condition (1) indicates that there is a vehicle 43 waiting in front of a stop line, etc., in order to pass through the crosswalk 41 in the third area 53 (vehicle approach area), or a vehicle 43 that is proceeding toward the crosswalk 41.

[0059] On the other hand, condition (2) indicates that there are no pedestrians 42 in the first area 51 (crossing area) and the second area 52 (pedestrian-side vicinity area). When conditions (1) and (2) are satisfied simultaneously, it means that there are no pedestrians 42 passing through or about to cross the crosswalk 41, and there are vehicles 43 waiting to cross the crosswalk 41 or heading toward the crosswalk 41. In such a case, the control unit 12 promptly transitions the signal level to turn the vehicle signal 32 green.

[0060] Condition (3) indicates that there is no moving object in the first area 51 (crossing area) for a period of time or longer, and that there is no moving object in the fourth area 54 (pedestrian crossing waiting area). The first period in condition (3) is, for example, 3 seconds. By transitioning the state when conditions (1) and (3) are satisfied simultaneously, pedestrians 42 can pass over the crosswalk 41 with reduced waiting time for vehicles 43 after they have finished crossing the crosswalk 41.

[0061] Condition (4) indicates that no moving object is present in the first area 51 (crossing area) for a period of time or longer, and a moving object is present in the fourth area 54 (pedestrian crossing waiting area) for a period of time or longer. In condition (4), the second period is, for example, 5 seconds, and the third period is, for example, 10 seconds. The condition that satisfies both conditions (1) and (4) simultaneously is the condition that prevents a vehicle 43 from being unable to pass over the crosswalk 41 when a pedestrian 42 who is not waiting to cross the crosswalk 41 is standing still in the fourth area 54 (pedestrian crossing waiting area).

[0062] Condition (5) indicates that the state in which no moving object is present in the first area 51 (crossing area) continues for two hours or more, and that a moving object is present in the fifth area 55 (pedestrian approaching crossing area) for three hours or more. In condition (4), the second hour is, for example, 5 seconds, and the third hour is, for example, 30 seconds. The third hour differs depending on whether a moving object is present in the fourth area 54 or in the fifth area 55 and no moving object is present in the fourth area 54. The condition that satisfies both conditions (1) and (5) simultaneously is the condition that prevents a vehicle 43 from being unable to pass on the crosswalk 41 if there is a pedestrian 42 in the fifth area 55 (pedestrian approaching crossing area) who is not waiting to cross the crosswalk 41.

[0063] The control unit 12 further initiates the transition of the pedestrian signal 31 and the vehicle signal 32 to the second state if the following condition (6) is met. Condition (6) indicates that there is a moving object in the third area 53 (vehicle approach area) and the first state has continued for four or more hours. The fourth hour in condition (6) is, for example, three minutes. According to this condition, if there are many pedestrians 42 crossing the crosswalk 41 and the line of pedestrians 42 is continuous, the control unit 12 initiates the transition to the second state four hours after a vehicle 43 is detected in the third area 53 (vehicle approach area). This ensures that the control unit 12 can pass over the crosswalk 41.

[0064] (Transition conditions from the second state to the first state) Figure 7 illustrates an example of the transition conditions from the second state to the first state. When condition (7) or (8) is satisfied, the control unit 12 transitions the state of the pedestrian signal 31 and the vehicle signal 32 from the second state to the first state. The numerical values ​​showing the time included in Figure 7 are merely examples. These values ​​can be changed as appropriate.

[0065] Condition (7) indicates that there are no moving objects in the first area 51 (crossing area) and the third area 53 (vehicle approach area) for a period of time of 5 or more. The 5th period in condition (7) is, for example, 1 second. This condition ensures that when the traffic signal 32 allows vehicles 43 to pass, and after a vehicle 43 has passed the crosswalk 41, there are no following vehicles 43 on the crosswalk 41 and on the road 45 leading to the crosswalk 41, pedestrians 42 are quickly allowed to cross the crosswalk 41.

[0066] Condition (8) indicates that if the second state continues for six hours or longer, a transition to the first state will begin. In (8), the sixth hour is, for example, two minutes. This condition indicates that the pedestrian signal 31 will be turned green if many vehicles 43 are traveling on the road 45 and the line of vehicles 43 is continuous, and / or if the transition from the second state to the first state under condition (7) does not begin due to unforeseen circumstances. Unforeseen circumstances include, for example, a vehicle 43 being parked for a long time on the roadside within the third area 53 (vehicle approach area). By transitioning to the first state under condition (8), the passage of pedestrians 42 across the crosswalk 41 is ensured.

[0067] As described above, according to the traffic signal control system 1 of this disclosure, the traffic signal control device 10 makes a decision to switch signals based on the combination of the presence or absence of moving objects in each of the multiple regions, and controls the pedestrian signal 31 and the vehicle signal 32. This method assumes the type and direction of travel of a moving object based on the arrangement and shape of the regions where the presence of a moving object is substantially determined, so it does not require processing such as identifying the type of moving object and predicting the direction of travel. Furthermore, since it does not perform complex image processing, it is less susceptible to the effects of weather and / or ambient brightness. Therefore, the traffic signal control system 1 of this disclosure can operate stably at a lower cost compared to conventional technology that uses a highly functional predictive model based on AI image processing.

[0068] In particular, the traffic signal control system 1 of this disclosure includes a fourth area 54 (pedestrian crossing waiting area) and a fifth area 55 (pedestrian approaching crossing area), which allows for determination that takes into account the intention of pedestrians 42 to cross the crosswalk 41. Furthermore, the traffic signal control system 1 is configured to switch states if a moving object remains in either area for a longer period of time than predetermined, thereby preventing the occurrence of a deadlock state in which the pedestrian signal 31 and the vehicle signal 32 fail to switch.

[0069] Furthermore, in the traffic signal control system 1 of this disclosure, the pedestrian signal 31 is set to a green state as the default state. As a result, in the traffic signal control system 1 of this disclosure, pedestrians 42 crossing the crosswalk 41 do not experience unnecessary waiting at the signal. In conventional traffic signals with a fixed-time switching system, pedestrians 42 may be forced to wait at the signal even if there are no vehicles 43 crossing the crosswalk 41 on the road for vehicles 45, which can cause frustration due to the unnecessary waiting time. Also, in traffic-actuated traffic signals that switch signals when they detect the presence of pedestrians 42, unnecessary waiting time can occur before the signal changes. The traffic signal control system 1 of this disclosure improves upon these problems of the conventional technology.

[0070] Furthermore, the traffic signal control system 1 of this disclosure is configured to detect moving objects in the third area 53 (vehicle approach area), which is the area where a vehicle 43 is approaching the pedestrian crossing 41. This makes it possible to detect not only vehicles 43 stopped at the stop line before the pedestrian crossing 41, but also vehicles 43 proceeding towards the pedestrian crossing 41. Therefore, if there are no pedestrians 42 walking or about to walk across the pedestrian crossing 41, the vehicle signal 32 can be quickly switched to green, allowing the vehicle 43 to pass through without stopping before the pedestrian crossing 41.

[0071] Furthermore, in the traffic signal control system 1 of this disclosure, since the detector 20 installed as road infrastructure, particularly a camera, is used to detect moving objects, there is no need to implement special equipment on the moving object side in order to detect moving objects, including pedestrians 42.

[0072] It should be noted that the present invention is not limited to the embodiments described above, and numerous modifications or alterations are possible. For example, the functions included in each means, step, etc., can be rearranged in a way that is not logically contradictory, and multiple means or steps, etc., can be combined into one or divided.

[0073] Some embodiments of the present disclosure are described below. However, it should be noted that the embodiments of the present disclosure are not limited to these. [Note 1] A communication unit that acquires detection results for detecting moving objects in multiple detection target areas around the pedestrian crossing, including the pedestrian crossing, Based on the detection results obtained by the communication unit, a control unit recognizes the combination of presence or absence of the moving object in each of the multiple regions and controls the pedestrian signal and the vehicle signal based on the combination. A traffic signal control device equipped with the following features. [Note 2] The control unit controls the pedestrian signal to indicate that pedestrians are allowed to pass when no moving object is present in any of the multiple areas, as described in Appendix 1. [Note 3] The aforementioned plurality of regions include a first region which is the region on the crosswalk, a second region which is the region where pedestrians pass near the crosswalk, and a third region which is the region where vehicles approaching the crosswalk pass. The signal control device according to Appendix 1 or 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition between a first state in which the pedestrian signal allows pedestrians to pass and the vehicle signal prohibits vehicles from passing, and a second state in which the pedestrian signal prohibits pedestrians from passing and the vehicle signal allows vehicles to pass, based on a combination of the presence or absence of a moving body in the first region, the second region, and the third region. [Note 4] The signal control device according to [Appendix 3], wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the first and second regions, and there are moving objects in the third region. [Note 5] The signal control device according to Appendix 3 or 4, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the second area, and there are moving objects in the third area, and a first time after the moving objects cease to be present in the first area. [Note 6] The signal control device according to any one of the appendices 3 to 5, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and a moving object is present in the third region, and the state in which no moving object is present in the first region continues for a second time or longer, and the state in which a moving object is present in the second region continues for a third time or longer. [Note 7] The signal control device according to Appendix 6, wherein the second region includes a fourth region adjacent to the pedestrian crossing and a fifth region located further away from the pedestrian crossing than the fourth region, and the third time differs depending on whether a moving object is present in the fourth region or whether a moving object is present in the fifth region but not in the fourth region. [Note 8] The signal control device according to any one of the appendices 3 to 7, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and a moving object is present in the third area for a fourth period of time. [Note 9] The signal control device according to any one of the appendices 3 to 8, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the first state when the pedestrian signal and the vehicle signal are in the second state and no moving objects exist in the first and third regions for a fifth period of time. [Note 10] The signal control device according to any one of the appendices 3 to 9, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the first state when the pedestrian signal and the vehicle signal are in the second state and the second state continues for a sixth time. [Note 11] The traffic signal control device according to any one of the appendices 1 to 10, wherein the moving body includes a plurality of different types of moving bodies, including pedestrians, bicycles, and vehicles, and the control unit does not distinguish between the types of the moving bodies. [Note 12] The communication unit is a signal control device according to any one of the appendices 1 to 11, which acquires the detection result from a camera having the function of identifying a moving object from an image it has captured. [Note 13] A signal control method performed by the control unit of a signal control device, To obtain detection results for multiple areas of the target to be detected, including the pedestrian crossing and its surroundings, in which case a moving object has been detected. Based on the detection results, the combination of presence or absence of the moving body in each region included in the plurality of regions is recognized, To control pedestrian signals and vehicle signals based on the above combination. A traffic signal control method including the following. [Note 14] The traffic signal control method according to Appendix 13, wherein the control unit controls the pedestrian traffic signal to display a sign indicating that pedestrians are allowed to pass when no moving object is present in any of the multiple areas. [Note 15] The aforementioned plurality of regions include a first region which is the region on the pedestrian crossing, a second region which is the region of the sidewalk adjacent to the pedestrian crossing, and a third region which is the region through which vehicles approaching the pedestrian crossing pass. The signal control method according to Appendix 13 or 14, wherein the control unit controls the pedestrian signal and the vehicle signal to transition between a first state in which the pedestrian signal allows pedestrians to pass and the vehicle signal prohibits vehicles from passing, and a second state in which the pedestrian signal prohibits pedestrians from passing and the vehicle signal allows vehicles to pass, based on a combination of the presence or absence of a moving body in the first region, the second region, and the third region. [Note 16] The signal control method according to Appendix 15, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the first and second regions, and there are moving objects in the third region. [Note 17] The signal control method according to Appendix 15 or 16, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the second area, and there are moving objects in the third area, and a first time after the moving objects cease to be present in the first area. [Note 18] The signal control method according to any one of the appendices 15 to 17, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and a moving object is present in the third region, and the state in which no moving object is present in the first region continues for a second time or longer, and the state in which a moving object is present in the second region continues for a third time or longer. [Note 19] The signal control method according to Appendix 18, wherein the second region includes a fourth region adjacent to the pedestrian crossing and a fifth region located further away from the pedestrian crossing than the fourth region, and the third time differs depending on whether a moving object is present in the fourth region or whether a moving object is present in the fifth region but not in the fourth region. [Note 20] Pedestrian and vehicle traffic signals are installed to control traffic at crosswalks, A detector for detecting moving objects is provided for multiple areas to be detected around the pedestrian crossing, including the aforementioned pedestrian crossing. A signal control device including a communication unit that acquires detection results of detecting a moving object from the detector, and a control unit that recognizes combinations of the presence or absence of the moving object in each of the plurality of regions based on the detection results, and controls the pedestrian signal and the vehicle signal based on the combination. A traffic signal control system equipped with the following features. [Explanation of symbols]

[0074] 1. Traffic Signal Control System 10 Traffic signal control device 11 Communications Department 12 Control Unit 12 20A, 20B detectors 31 Pedestrian traffic signals 32 Traffic signals for vehicles 41 Pedestrian crossing 42 Pedestrians (moving objects) 43. Vehicles (mobile objects) 44 Pedestrian walkway 45 Roads for vehicles 51. First area (cross-sectional area) 52 Second area (nearby area on the pedestrian side) 53. Third area (vehicle approach area) 54. Area 4 (Pedestrian crossing waiting area) 55. Area 5 (Pedestrian Crossing Approach Area)

Claims

1. A communication unit that acquires detection results for detecting moving objects in multiple detection target areas around the pedestrian crossing, including the pedestrian crossing, Based on the detection results obtained by the communication unit, a control unit recognizes the combination of presence or absence of the moving object in each of the multiple regions and controls the pedestrian signal and the vehicle signal based on the combination. Equipped with, The control unit controls the pedestrian signal to indicate that pedestrians are allowed to pass when no moving object is present in any of the multiple areas.

2. The aforementioned plurality of regions include a first region which is the region on the crosswalk, a second region which is the region where pedestrians pass near the crosswalk, and a third region which is the region where vehicles approaching the crosswalk pass. The signal control device according to claim 1, wherein the control unit controls the pedestrian signal and the vehicle signal to transition between a first state in which the pedestrian signal allows pedestrians to pass and the vehicle signal prohibits vehicles from passing, and a second state in which the pedestrian signal prohibits pedestrians from passing and the vehicle signal allows vehicles to pass, based on a combination of the presence or absence of a moving body in the first region, the second region, and the third region.

3. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the first and second regions, and there are moving objects in the third region.

4. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state a first time after the pedestrian signal and the vehicle signal are in the first state, there are no moving objects in the second area, and there are moving objects in the third area.

5. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and a moving object is present in the third region, and the state in which no moving object is present in the first region continues for a second time or longer, and the state in which a moving object is present in the second region continues for a third time or longer.

6. The signal control device according to claim 5, wherein the second region includes a fourth region adjacent to the pedestrian crossing and a fifth region located further away from the pedestrian crossing than the fourth region, and the third time differs depending on whether a moving object is present in the fourth region or whether a moving object is present in the fifth region but not in the fourth region.

7. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and the state in which a moving object is present in the third area continues for a fourth time.

8. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the first state when the pedestrian signal and the vehicle signal are in the second state and no moving objects exist in the first and third regions for a fifth period of time.

9. The signal control device according to claim 2, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the first state when the pedestrian signal and the vehicle signal are in the second state and the second state continues for a sixth time.

10. The traffic signal control device according to claim 1, wherein the moving body includes a plurality of different types of moving bodies, including pedestrians, bicycles and vehicles, and the control unit does not distinguish between the types of the moving bodies.

11. The signal control device according to claim 1, wherein the communication unit acquires the detection result from a camera having the function of identifying a moving object from an image it has captured.

12. A signal control method performed by the control unit of a signal control device, To obtain detection results for multiple areas of the target to be detected, including the pedestrian crossing and its surroundings, in which case a moving object has been detected. Based on the detection results, the combination of presence or absence of the moving body in each region included in the plurality of regions is recognized, To control pedestrian signals and vehicle signals based on the above combination. Includes, A traffic signal control method comprising: the control unit controlling the pedestrian signal to display a signal indicating that pedestrians are permitted to pass when no moving object is present in any of the multiple regions.

13. The aforementioned plurality of regions include a first region which is the region on the pedestrian crossing, a second region which is the region of the sidewalk adjacent to the pedestrian crossing, and a third region which is the region through which vehicles approaching the pedestrian crossing pass. The traffic signal control method according to claim 12, wherein the control unit controls the pedestrian traffic signal and the vehicle traffic signal to transition between a first state in which the pedestrian traffic signal allows pedestrians to pass and the vehicle traffic signal prohibits vehicles from passing, and a second state in which the pedestrian traffic signal prohibits pedestrians from passing and the vehicle traffic signal allows vehicles to pass, based on a combination of the presence or absence of a moving body in the first region, the second region, and the third region.

14. The traffic signal control method according to claim 13, wherein the control unit controls the pedestrian traffic signal and the vehicle traffic signal to transition to the second state when the pedestrian traffic signal and the vehicle traffic signal are in the first state, there are no moving objects in the first and second regions, and there are moving objects in the third region.

15. The traffic signal control method according to claim 13, wherein the control unit controls the pedestrian traffic signal and the vehicle traffic signal to transition to the second state a first time after the pedestrian traffic signal and the vehicle traffic signal are in the first state, there are no moving objects in the second area, and there are moving objects in the third area.

16. The signal control method according to claim 13, wherein the control unit controls the pedestrian signal and the vehicle signal to transition to the second state when the pedestrian signal and the vehicle signal are in the first state and a moving object is present in the third region, and the state in which no moving object is present in the first region continues for a second time or longer, and the state in which a moving object is present in the second region continues for a third time or longer.

17. The traffic signal control method according to claim 16, wherein the second region includes a fourth region adjacent to the pedestrian crossing and a fifth region located further away from the pedestrian crossing than the fourth region, and the third time differs depending on whether a moving object is present in the fourth region or whether a moving object is present in the fifth region but not in the fourth region.

18. Pedestrian and vehicle traffic signals are installed to control traffic at crosswalks, A detector for detecting moving objects is provided for multiple areas to be detected around the pedestrian crossing, including the aforementioned pedestrian crossing. A signal control device includes a communication unit that acquires detection results of detecting a moving object from the detector, and a control unit that recognizes combinations of the presence or absence of the moving object in each of the multiple regions based on the detection results, and controls the pedestrian signal and the vehicle signal based on the combination, wherein the control unit controls the pedestrian signal to display a message indicating that pedestrians are allowed to pass if no moving object is present in any of the multiple regions, and A traffic signal control system equipped with the following features.

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