Traffic light control device, traffic light control method, and traffic light 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 light control device, a traffic light control method, and a traffic light control system. [Background technology]

[0002] Conventionally, a pedestrian crossing signal system has been proposed that detects waiting pedestrians waiting to cross a pedestrian crossing and controls pedestrian and vehicle traffic lights by recall control based on the detection of waiting pedestrians (see, for example, Patent Document 1). According to Patent Document 1, an image including a pedestrian standing in front of a pedestrian crossing is captured by an imaging device, and a predetermined image analysis is performed on the captured image to determine whether the pedestrian is a waiting pedestrian about to cross the pedestrian crossing. This image analysis includes processes such as extraction of a person captured in an image portion corresponding to a waiting area in the captured image, tracking of the extracted person, and determination of the line of sight of the extracted person. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-208141 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional methods for controlling traffic lights at pedestrian crossings use complex image processing to predict pedestrians' intentions to cross the street, which can lead to inconsistent judgments. In addition, it can be difficult to determine the direction of a pedestrian's line of sight, depending on weather, brightness, and other conditions. In other words, conventional technology requires advanced image recognition, which is not robust enough to ensure stable operation.

[0005] In view of the above circumstances, an object of the present disclosure is to improve the technology for traffic light control at pedestrian crossings. [Means for solving the problem]

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

[0007] Furthermore, a traffic light control method according to one embodiment of the present disclosure is a traffic light control method executed by a control unit of a traffic light control device, and includes obtaining detection results of moving objects in a plurality of detection target areas surrounding a crosswalk including a crosswalk, recognizing a combination of the presence or absence of the moving object in each of the plurality of areas based on the detection results, and controlling a pedestrian traffic light and a vehicle traffic light based on the combination.

[0008] Moreover, a traffic light control system according to one embodiment of the present disclosure includes a pedestrian traffic light and a vehicular traffic light arranged to control passage across 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 moving object detection from the detector, and a traffic light control device including a control unit that recognizes combinations of the presence or absence of the moving object for each area included in the plurality of areas based on the detection results, and controls the pedestrian traffic light and the vehicular traffic light based on the combinations. Effect of the Invention

[0009] According to the present disclosure, the technology for controlling traffic lights at pedestrian crossings can be improved. [Brief description of the drawings]

[0010] [Figure 1]1 is a block diagram showing a schematic configuration of a traffic light control system according to an embodiment of the present disclosure. [Diagram 2] 2 is a plan view illustrating an example of the arrangement of components of the traffic light control system and detection target areas in FIG. 1. [Diagram 3] FIG. 2 is a diagram showing an example of a signal phase diagram for the pedestrian traffic light and the vehicular traffic light of FIG. 1. [Figure 4] 4 is a flowchart showing an example of a traffic light control process performed by a traffic light control device. [Diagram 5] 5 is a flowchart showing an example of a process for determining switching of a traffic light in FIG. 4. [Figure 6] FIG. 4 is a diagram illustrating an example of a transition condition from a first state to a second state. [Figure 7] FIG. 11 is a diagram illustrating an example of a transition condition from the second state to the first state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the drawings used in the following description are schematic. The dimensions and ratios in the drawings do not necessarily correspond to the real ones.

[0012] (Configuration of the signal control system) 1, a traffic light control system 1 according to an embodiment of the present disclosure includes a traffic light control device 10, one or more detectors 20, a pedestrian traffic light 31, and a vehicle traffic light 32. The traffic light control device 10 is communicatively connected to each of the detectors 20, the pedestrian traffic light 31, and the vehicle traffic light 32 via wired communication means and / or wireless communication means.

[0013] The traffic light control device 10 is a computer that controls the pedestrian traffic light 31 and the vehicular traffic light 32. The traffic light control device 10 may be disposed adjacent to the pedestrian traffic light 31 and the vehicular traffic light 32. At least a part of the functions of the traffic light control device 10 may be disposed in a remote location away from the pedestrian traffic light 31 and the vehicular traffic light 32. The traffic light control device 10 includes a communication unit 11, a control unit 12, and a memory unit 13.

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

[0015] The control unit 12 is configured to include a single or multiple processors and memories. The processors include general-purpose processors that execute programmed functions by loading specific programs, and dedicated processors specialized for specific processing. The control unit 12 loads programs for traffic light control and controls the pedestrian traffic light 31 and the vehicle traffic light 32. The control unit 12 executes various calculations for controlling the pedestrian traffic light 31 and the vehicle traffic light 32.

[0016] The storage unit 13 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or a combination of at least two of these. The storage unit 13 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 13 stores programs and data used in the operation of the traffic light control device 10, and data obtained by the operation of the traffic light control device 10. Each piece of information stored in the storage unit 13 may be updatable, for example, with information acquired from the communication unit 11.

[0017] The traffic light 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 a button switch, a touch panel, etc. that allows the manager of the traffic light control system 1 to directly operate the system. The display unit includes a display such as an LCD (liquid crystal display) for displaying information in response to operations by the manager.

[0018] The detector 20 is a sensor that detects a moving object in the surrounding area of ​​the crosswalk 41 including the crosswalk 41 (see FIG. 2). In the present disclosure, a moving object means a person or object that can move. The moving object may be stationary at a certain moment. The moving object may include multiple types of people or objects such as a pedestrian 42, a vehicle 43, a bicycle, and a personal mobility vehicle (PMV). The moving object may be referred to as a traffic participant. The detector 20 does not need to distinguish the type of the moving object. Two or more detectors 20 may be arranged to detect a moving object in a predetermined surrounding area. The detector 20 is configured to transmit a detection result to the traffic light control device 10. The detection result of the detector 20 is used to recognize the presence or absence of a moving object in each of multiple areas included in the surrounding area of ​​the crosswalk 41 including the crosswalk 41.

[0019] Detector 20 is, for example, a camera fixed to a structure such as a traffic light or a utility pole adjacent to crosswalk 41 and captures an image of the area surrounding crosswalk 41. The camera is not limited to a camera that captures images using visible light, and may include an infrared camera that captures images using light with infrared wavelengths. When detector 20 is a camera, in this disclosure, "detecting a moving object" is used to mean both simply capturing an image including a moving object and identifying the moving object from the captured 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 performs AI processing on an image captured inside the camera and can transmit the processing result to the traffic light control device 10. The edge AI camera can identify a moving object from the captured image and transmit information on the identified moving object to the traffic light control device 10 together with the captured image.

[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 the detection result to the traffic light control device 10. The detection of a moving object for each region 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 in a specific area. The detector 20 may include, for example, an ultrasonic sensor and / or an infrared sensor fixed to a structure on the pedestrian road 44 and / or the vehicle road 45. The detector 20 may also be a sensor buried in the vehicle road 45, such as a loop coil detector. The detector 20 may be arranged at the edge of the specific area to detect the presence or absence of a moving object entering or leaving the specific area.

[0023] Pedestrian traffic lights 31 and vehicle traffic lights 32 are positioned to control traffic on the crosswalk 41 .

[0024] The pedestrian traffic lights 31 are traffic lights arranged on both sides of the vehicular road 45 across the crosswalk 41. The pedestrian traffic lights 31 are arranged with their light-emitting parts facing the direction facing the pedestrian 42 crossing the crosswalk 41. The pedestrian traffic lights 31 display to the pedestrian 42 that the crosswalk 41 is passable or not passable. For example, the pedestrian traffic lights 31 include a blue light-emitting part and a red light-emitting part. When the blue light-emitting part is lit, it indicates that the pedestrian 42 is passable. When the red light-emitting part is lit, it indicates that the pedestrian 42 is not passable. Before the blue light-emitting part is switched from a lit state to a lit state, the blue light-emitting part flashes to notify that the signal is about to be switched. The pedestrian traffic lights 31 are controlled by the traffic light control device 10.

[0025] The vehicle traffic light 32 is a traffic light arranged facing the driver of the vehicle 43 on the vehicle road 45 across the crosswalk 41. The vehicle traffic light 32 displays to the driver of the vehicle 43 whether the vehicle 43 can pass or cannot pass on the crosswalk 41. For example, the vehicle traffic light 32 has blue, red, and yellow light-emitting parts. The blue light-emitting part indicates that the vehicle 43 can pass on the crosswalk 41. The red light-emitting part indicates that the vehicle 43 cannot pass on the crosswalk 41. The green light changes to a yellow light before turning to red. The vehicle traffic light 32 is controlled by the traffic light control device 10.

[0026] The pedestrian traffic light 31 and the vehicle traffic light 32 are not limited to those that indicate whether passage is permitted or not by the color of the light-emitting part as described above. For example, the pedestrian traffic light 31 and / or the vehicle traffic light 32 may display an arrow to indicate that passage is permitted. Also, the color of the light-emitting part indicating that passage is permitted may be green instead of blue. In the following, in order to simplify the explanation, the state displayed by the traffic light may be described using the colors displayed by the traffic light, such as green, red, and yellow.

[0027] (Example of areas and device placement around pedestrian crossings) FIG. 2 shows an example of a crosswalk 41 at a position where a pedestrian road 44 and a vehicle road 45 intersect, a plurality of detection target areas, and an arrangement of each component of the traffic light control system 1.

[0028] The pedestrian road 44 is a road on which not only pedestrians 42 but also bicycles and PMVs travel. Pedestrians 42, bicycles and PMVs are included in the mobile objects. Mobile objects traveling on the pedestrian road 44 cross the crosswalk 41 in accordance with the pedestrian traffic light 31. Since the traffic light control system 1 does not distinguish between types of mobile objects, a mobile object traveling on the pedestrian road 44 is essentially treated as a pedestrian 42.

[0029] The vehicle road 45 is a road on which not only vehicles 43 but also bicycles and PMVs travel. Vehicles 43, bicycles and PMVs are included in the mobile objects. Mobile objects traveling on the vehicle road 45 travel on the vehicle road 45 according to the vehicle traffic lights 32. Since the traffic light control system 1 does not identify the type of mobile object, the mobile object traveling on the vehicle road 45 is substantially treated as a vehicle 43.

[0030] The detection target area of ​​the crosswalk 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 an area on the crosswalk 41. The second area 52 is an area where pedestrians 42 near the crosswalk 41 pass. The third area 53 is an area where vehicles 43 heading to the crosswalk 41 pass. The third area 53 may be an area on the lane heading to the crosswalk 41 of the vehicle road 45 from a predetermined distance before the crosswalk 41 to just before the crosswalk 41. The predetermined distance can be set arbitrarily according to the road environment, for example, 30 m, 50 m, or 100 m. In the following, the first area 51, the second area 52, and the third area 53 may also be referred to as a crossing area area, a pedestrian side vicinity area, and a vehicle approach area, respectively. The second area 52 exists on each side of the vehicle road 45. The third areas 53 are located on both the left and right sides of the center line 46 of the road 45 for vehicles.

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

[0032] In the example of FIG. 2, two detectors 20A and 20B are provided as the detector 20 on both sides of the road with the crosswalk 41 between them. In one embodiment, the detectors 20A and 20B may each be equipped with one or more edge AI cameras. For example, the detector 20A may be configured to capture an image of the first region 51, and the second region 52 and the third region 53 located on the detector 20A side (left side in FIG. 2) of the center line 46 of the road 45 for vehicles. The detector 20B may be configured to capture an image of the first region 51, and the second region 52 and the third region 53 located on the detector 20B side (right side in FIG. 2) of the center line 46 of the road 45 for vehicles.

[0033] The detectors 20A and 20B, which are edge AI cameras, detect whether or not a moving object exists in the area to be detected. The detectors 20A and 20B only need to detect the presence or absence of a moving object and its location (area), and do not need to analyze the type, orientation, direction of travel, speed, etc. of the moving object. For this reason, the detectors 20A and 20B do not need to perform complex image processing. The number of detectors 20 is not limited to two. The detector 20 may include a sufficient number of edge AI cameras to include the first area 51 to the fifth area 55 around the crosswalk 41 as the area to be imaged. The edge AI cameras may be connected to each other in communication with each other, and may be configured to be able to integrate detection information of moving objects in the entire area around the crosswalk 41. Information on the presence or absence of a moving object in the first area 51 to the fifth area 55 and its location detected by the detector 20A is transmitted to the traffic light control device 10.

[0034] The control unit 12 of the traffic light control device 10 integrates the information of the detection results acquired from each of the detectors 20A and 20B via the communication unit 11, and determines whether or not a moving object is present in each of the first to fifth regions 51 to 55 as a whole. This presence determination is performed by integrating the detection results of all the detectors 20. In order to prevent judgment hunting (fluctuation) caused by detection hunting (fluctuation), the control unit 12 determines that a moving object is present in an area when detection of a moving object continues within the area for a certain period of time (e.g., 0.3 seconds or more). The same applies when changing the judgment of the presence or absence of a moving object from "present" to "not present."

[0035] The control unit 12 recognizes a combination of the presence or absence of a moving object, i.e., a traffic participant such as a pedestrian 42 and a vehicle 43, for each of the areas included in the first area 51 to the fifth area 55. The control unit 12 judges the status of the traffic participants such as the pedestrian 42 and the vehicle 43 at the crosswalk 41 and its surroundings based on this combination. The control unit 12 judges, for example, the presence or absence of a pedestrian 42 crossing the crosswalk 41, the presence or absence of a pedestrian 42 waiting to cross at the crosswalk 41, and the presence or absence of a vehicle 43 approaching the crosswalk 41 or a vehicle 43 waiting for a traffic light in front of the crosswalk 41. The control unit 12 controls the pedestrian traffic light 31 and the vehicle traffic light 32 based on the combination of the presence or absence of a moving object for each of the first area 51 to the fifth area 55.

[0036] The traffic light control system 1 disclosed herein does not control the pedestrian traffic lights 31 and the vehicle traffic lights 32 by calculating the time it takes for a moving object to reach the crosswalk 41. The traffic light control system 1 disclosed herein determines whether a moving object is approaching the crosswalk 41 and whether it is waiting, etc., based on a combination of the arrangement and shape of the areas of each detection target and the presence or absence of a moving object.

[0037] In one embodiment, the control unit 12 may control the pedestrian traffic light 31 to indicate that the pedestrian 42 can pass when there is no moving object in any of the first area 51 to the third area 53. That is, the control unit 12 may control the pedestrian traffic light 31 and the vehicle traffic light 32 to turn the pedestrian traffic light 31 red and the vehicle traffic light 32 green only when a predetermined transition condition is satisfied, with the pedestrian traffic light 31 being green as a basic state. In this way, it is possible to reduce the time that the pedestrian 42 who has reached the crosswalk 41 waits for the pedestrian traffic light 31 to change from red to green. In addition, by setting the pedestrian traffic light 31 to green as a basic state, when there is no moving object in at least the third area 53, it becomes unnecessary to analyze whether the pedestrian 42 intends to pass the crosswalk 41 from an image of the pedestrian 42 approaching the crosswalk 41.

[0038] (Signal phase diagram) The control unit 12 controls signal switching between the pedestrian traffic light 31 and the vehicle traffic light 32, for example, in accordance with the signal phase diagram of FIG.

[0039] Staircase 1 is a stage where the pedestrian traffic light 31 is green and the vehicle traffic light 32 is red. The state of Staircase 1 is the first state. Staircase 1 can be the basic state of the pedestrian traffic light 31 and the vehicle traffic light 32 in the traffic light control system 1. The dashed arrow in the frame of the flow diagram of the sequence from Staircase 1 to Staircase 3 indicates the movement direction of the pedestrian 42 represented by "1P". When the judgment condition illustrated in FIG. 6 described later is satisfied on Staircase 1, the control unit 12 instructs a transition to Staircase 2.

[0040] Staircase 2 is a stage where the pedestrian traffic light 31 is a flashing green signal and the vehicle traffic light 32 is a red signal. The control unit 12 continues the stage 2 for a predetermined safety number of seconds, and then transitions to the stage 3. In the example of FIG. 3, the safety number of seconds for the stage 2 is 8 seconds.

[0041] Staircase 3 is a stairs where pedestrian traffic light 31 and vehicle traffic light 32 are red. After a predetermined safety number of seconds has elapsed on stairs 3, control unit 12 transitions to stairs 4. In the example of FIG. 5, the predetermined safety number of seconds is 2 seconds.

[0042] Stair 4 is a stage where the pedestrian traffic light 31 is red and the vehicle traffic light 32 is green. The state of Stair 4 is the second state. At Stair 4, pedestrians 42 are not allowed to cross the crosswalk 41. At Stair 4, vehicles 43 are allowed to cross the crosswalk 41 of the vehicle road 45. The arrow shown by a solid line within the frame of the flow diagram of the column from Stair 4 to Stair 6 indicates the moving direction of the vehicle 43 represented by "2G". When the judgment condition illustrated in FIG. 7 is satisfied at Stair 4, the control unit 12 instructs a transition to Stair 5.

[0043] Staircase 5 is a stage where the pedestrian traffic light 31 is red and the vehicle traffic light 32 is yellow. The control unit 12 continues on stairs 5 for a predetermined number of safety seconds, and then transitions to stairs 6. In the example of FIG. 5, the number of safety seconds on stairs 6 is 6 seconds.

[0044] Staircase 6 is a stairs where pedestrian traffic light 31 and vehicle traffic light 32 are red. After a predetermined safety number of seconds has elapsed on stairs 6, control unit 12 transitions to stairs 1. In the example of FIG. 5, the predetermined safety number of seconds is 2 seconds.

[0045] The safety seconds shown in Fig. 3 are just an example. The safety seconds may be set to an appropriate value depending on the traffic environment, traffic volume, and the like.

[0046] As shown in FIG. 3, in the traffic light control system 1, when a predetermined judgment condition is satisfied in the first state, ie, the floor 1, and the second state, ie, the floor 4, the transition to the next floor is started. In the first state, the pedestrian traffic light 31 allows the pedestrian 42 to pass and the vehicle traffic light 32 prohibits the vehicle 43 from passing. In the second state, the pedestrian traffic light 31 prohibits the pedestrian 42 from passing and the vehicle traffic light 32 permits the vehicle 43 to pass. The floors 2, 3, 5, and 6 transition to the next floor after a predetermined number of safety seconds has elapsed. That is, the control unit 12 sequentially repeats the process of switching the pedestrian traffic light 31 and the vehicle traffic light 32 between the first state and the second state. The floors 2, 3, 5, and 6 can be regarded as transition states between the first state and the second state.

[0047] (Processing of signal control device) The procedure of the traffic light control method executed by the traffic light control device 10 will be described with reference to the flowchart of Fig. 4. The method disclosed in this specification 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-transitory computer-readable medium. Examples of non-transitory computer-readable media include a hard disk, a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, a CD-ROM (Compact Disc Read only memory), and the like. The non-transitory computer-readable medium is not limited to these.

[0048] First, the detector 20 detects a moving object in a detection target area. The control unit 12 of the traffic light 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 information on the detection results acquired from the detector 20, which is, for example, an edge AI camera, and recognizes the presence or absence of a moving object for each detection target area (S12).

[0050] The control unit 12 judges whether to switch the pedestrian traffic light 31 and the vehicular traffic light 32 based on the combination of the presence or absence of a moving object for each area according to the recognition result in S12 (S13). This switching judgment is made by making a judgment to transition the pedestrian traffic light 31 and the vehicular traffic light 32 between a first state and a second state, as shown in Fig. 5. The signal switching judgment process in Fig. 5 will be described below.

[0051] First, when the pedestrian traffic light 31 and the vehicle traffic light 32 are in a state transition between the first state and the second state (S21: Yes), the control unit 12 waits until the pedestrian traffic light 31 and the vehicle traffic light 32 enter either the first state or the second state (S21: Yes). That is, when the pedestrian traffic light 31 and the vehicle traffic light 32 are in the state of stairs 2 and 3 in the signal aspect stage diagram of Fig. 3, the control unit 12 waits until the transition to stairs 4 is completed. Also, when the pedestrian traffic light 31 and the vehicle traffic light 32 are in the state of stairs 5 and 6 in the signal aspect stage diagram of Fig. 3, the control unit 12 waits until the transition to stairs 1 is completed.

[0052] Next, if the current state of the pedestrian traffic light 31 and the vehicle traffic light 32 is the first state (step 1) (S22: Yes), the control unit 12 determines whether the transition condition to the second state (step 4) is satisfied (S23). The control unit 12 determines whether the combination of the presence or absence of a moving object for each area acquired from the detector 20 satisfies the transition condition to the second state shown in FIG.

[0053] If the transition condition to the second state is satisfied in S23 (S23: Yes), the control unit 12 determines to execute signal switching to the second state (S24). If the transition condition to the second state is not satisfied in S23 (S23: No), the control unit 12 repeats the determination of S23 until the transition condition to the second state is satisfied. As a result, when the transition condition to the second state is finally satisfied, the control unit 12 determines to switch to the second state (S24).

[0054] Furthermore, in S22, if the current state of the pedestrian traffic light 31 and the vehicle traffic light 32 is the second state (step 4) (S22: No), the control unit 12 determines whether the transition condition to the first state (step 1) is satisfied (S25). The control unit 12 determines whether the combination of the presence or absence of a moving object for each area acquired from the detector 20 satisfies the transition condition to the first state shown in FIG.

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

[0056] Returning to FIG. 4, the control unit 12 instructs the pedestrian traffic light 31 and the vehicle traffic light 32 to switch between the first state and the second state based on the judgment result of S13 (S24 and S26). When switching from the first state to the second state, the control unit 12 transitions the pedestrian traffic light 31 and the vehicle traffic light 32 from stage 1 to stage 4 in sequence according to the signal aspect stage diagram of FIG. 3. When switching from the second state to the first state, the control unit 12 transitions the pedestrian traffic light 31 and the vehicle traffic light 32 from stage 4 to stage 1 in sequence according to the signal aspect stage diagram of FIG. 3. In this manner, the control unit 12 sequentially switches the pedestrian traffic light 31 and the vehicle traffic light 32 to allow the pedestrian 42 and the vehicle 43 to pass through the crosswalk 41 in sequence.

[0057] (Transition condition from 1st state to 2nd state) Next, an example of a transition condition from the first state to the second state will be described with reference to Fig. 6. The values ​​indicating the time included in Fig. 6 are merely examples. These values ​​can be changed as appropriate.

[0058] The control unit 12 starts the transition of the pedestrian traffic light 31 and the vehicular traffic light 32 to the second state when condition (1) and any one of conditions (2) to (5) described below are satisfied at the same time. Condition (1) is a condition that the presence of a moving object in the third area 53 (vehicle approaching area) continues for one second or more. In other words, condition (1) indicates that there is a vehicle 43 waiting in front of a stop line or the like to pass the crosswalk 41 in the third area 53 (vehicle approaching area), or a vehicle 43 proceeding toward the crosswalk 41.

[0059] On the other hand, condition (2) is a condition indicating that there are no pedestrians 42 in the first area 51 (crossing area) and the second area 52 (pedestrian side vicinity area). A case where conditions (1) and (2) are satisfied simultaneously means that there are no pedestrians 42 crossing or about to cross the crosswalk 41, and there is a vehicle 43 waiting to cross the crosswalk 41 or heading towards the crosswalk 41. In such a case, the control unit 12 transitions the stairs so as to quickly turn the vehicle traffic light 32 green.

[0060] Condition (3) indicates that a state in which no moving object is present in first area 51 (crossing area) continues for a first time period or more, and that no moving object is present in fourth area 54 (pedestrian crossing waiting area). The first time period in condition (3) is, for example, three seconds. By transitioning the state when conditions (1) and (3) are satisfied simultaneously, after pedestrian 42 has crossed crosswalk 41, vehicle 43 can pass over crosswalk 41 with reduced wasted waiting time.

[0061] Condition (4) indicates that a state in which no moving object is present in first area 51 (crossing area) continues for a second time or more, and a moving object is present in fourth area 54 (pedestrian waiting area for crossing) for a third time or more. The second time in condition (4) is, for example, 5 seconds, and the third time is, for example, 10 seconds. A condition that simultaneously satisfies conditions (1) and (4) is a condition that prevents a state in which vehicles 43 cannot pass over crosswalk 41 from continuing when pedestrians 42 who are not waiting to cross crosswalk 41 are standing in fourth area 54 (pedestrian waiting area for crossing).

[0062] Condition (5) indicates that a state in which no moving object is present in the first area 51 (crossing area) continues for a second time or more, and a moving object is present in the fifth area 55 (crossing pedestrian approach area) for a third time or more. The second time in condition (4) is, for example, 5 seconds, and the third time is, for example, 30 seconds. The third time differs between a case in which a moving object is present in the fourth area 54 and a case in which a moving object is present in the fifth area 55 but is not present in the fourth area 54. The condition for simultaneously satisfying conditions (1) and (5) is a condition for preventing a state in which vehicles 43 cannot pass on the crosswalk 41 from continuing when a state in which pedestrians 42 who are not waiting to cross the crosswalk 41 continue to be present in the fifth area 55 (crossing pedestrian approach area).

[0063] The control unit 12 further starts the transition of the pedestrian traffic light 31 and the vehicle traffic light 32 to the second state when the following condition (6) is satisfied. The condition (6) indicates that there is a moving object in the third area 53 (vehicle approach area) and the first state continues for a fourth time or more. The fourth time in the condition (6) is, for example, three minutes. According to this condition, when there are many pedestrians 42 passing through the crosswalk 41 and the line of pedestrians 42 is continuous, the control unit 12 starts the transition to the second state after the fourth time has elapsed since the vehicle 43 was detected in the third area 53 (vehicle approach area). In this way, the control unit 12 ensures that the vehicle 43 can pass over the crosswalk 41.

[0064] (Transition condition from the second state to the first state) Fig. 7 is a diagram for explaining an example of a transition condition 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 traffic light 31 and the vehicular traffic light 32 from the second state to the first state. The numerical values ​​indicating the time included in Fig. 7 are merely an example. These numerical values ​​can be changed as appropriate.

[0065] Condition (7) indicates that a state in which there are no moving objects in the first area 51 (crossing area) and the third area 53 (vehicle approach area) continues for a fifth time or more. The fifth time in condition (7) is, for example, one second. This condition allows the pedestrian 42 to pass through the crosswalk 41 immediately when the vehicle 43 passes through the crosswalk 41 in a state in which the vehicle traffic light 32 allows the vehicle 43 to pass and there are no following vehicles 43 on the crosswalk 41 or on the vehicle road 45 leading to the crosswalk 41.

[0066] Condition (8) indicates that if the second state continues for a sixth time or more, a transition to the first state is initiated. In (8), the sixth time is, for example, two minutes. This condition indicates that the pedestrian traffic light 31 is turned green when many vehicles 43 are passing through the vehicle road 45 and the line of vehicles 43 continues uninterrupted, and / or when the transition from the second state to the first state due to condition (7) is not initiated due to an unexpected situation. An unexpected situation is, for example, when a vehicle 43 is parked for a long time on the roadside in the third area 53 (vehicle approach area). By transitioning to the first state due to condition (8), passage of pedestrians 42 on the crosswalk 41 is ensured.

[0067] As described above, according to the traffic light control system 1 of the present disclosure, the traffic light control device 10 determines whether to switch signals based on a combination of the presence or absence of a moving object for each of a plurality of areas, and controls the pedestrian traffic light 31 and the vehicle traffic light 32. This method does not require processing such as identification of the type of moving object and prediction of the moving direction, since it assumes the type and direction of the moving object based on the arrangement and shape of the area in which the presence of the moving object is essentially determined. In addition, since no complex image processing is performed, it is less susceptible to the effects of weather and / or surrounding brightness. Therefore, the traffic light control system 1 of the present disclosure can operate stably at a low cost compared to conventional techniques that use highly functional prediction models using AI image processing.

[0068] In particular, in the traffic light control system 1 disclosed herein, by providing a fourth area 54 (pedestrian waiting area to cross) and a fifth area 55 (crossing pedestrian approach area), it is possible to make a judgment that takes into consideration the intention of the pedestrian 42 to cross the crosswalk 41. Furthermore, in the traffic light control system 1, if a state in which a moving object is present in either area continues for a predetermined time or longer, the state is switched, so it is possible to prevent the occurrence of a deadlock state in which the pedestrian traffic light 31 and the vehicle traffic light 32 do not switch.

[0069] In addition, in the traffic light control system 1 of the present disclosure, the pedestrian traffic light 31 is set to a green state as the basic state. As a result, in the traffic light control system 1 of the present disclosure, there is no unnecessary waiting for the traffic light for the pedestrian 42 crossing the crosswalk 41. In a conventional traffic light with a fixed-time switching system, the pedestrian 42 may be forced to wait for the traffic light even when there is no vehicle 43 crossing the crosswalk 41 on the vehicle road 45, and may feel frustrated due to the unnecessary waiting time. Also, even in a sensor-based traffic light that detects the presence of a pedestrian 42 and switches the traffic light, there may be unnecessary waiting time until the traffic light is switched. The traffic light control system 1 of the present disclosure improves these problems of the conventional technology.

[0070] Furthermore, the traffic light control system 1 disclosed herein is adapted to detect moving objects present in the third area 53 (vehicle approach area) which is an area where the vehicle 43 heads toward the crosswalk 41. This makes it possible to detect not only the vehicle 43 stopped at the stop line before the crosswalk 41, but also the presence of the vehicle 43 proceeding toward the crosswalk 41. Therefore, when there is no pedestrian 42 walking or attempting to walk on the crosswalk 41, the vehicle traffic light 32 is quickly switched to green, making it possible for the vehicle 43 to pass through in front of the crosswalk 41 without stopping.

[0071] Furthermore, in the traffic light control system 1 disclosed herein, moving objects are detected using the detector 20 installed as road infrastructure, in particular a camera, so there is no need to implement special equipment on the moving object side to detect moving objects, including pedestrians 42.

[0072] The present invention is not limited to the above-described embodiment, and many variations or modifications are possible. For example, the functions included in each means, step, etc. can be rearranged so as not to cause logical inconsistencies, and multiple means or steps can be combined into one or divided.

[0073] Some of the embodiments of the present disclosure will be described below as examples. However, it should be noted that the embodiments of the present disclosure are not limited to these examples. [Appendix 1] A communication unit that acquires a detection result of detecting a moving object in a plurality of detection target areas including a crosswalk and surrounding the crosswalk; a control unit that recognizes a combination of the presence or absence of the moving object for each of the plurality of areas based on the detection results acquired by the communication unit, and controls a pedestrian traffic light and a vehicle traffic light based on the combination; A traffic light control device comprising: [Appendix 2] The control unit controls the pedestrian traffic light to indicate that pedestrians are allowed to pass when there is no moving object in any of the multiple areas. [Appendix 3] The plurality of areas include a first area which is an area on the crosswalk, a second area which is an area where pedestrians near the crosswalk pass, and a third area which is an area where vehicles heading toward the crosswalk pass, The control unit controls the pedestrian traffic light and the vehicular traffic light to transition between a first state in which the pedestrian traffic light allows pedestrians to pass and the vehicular traffic light does not allow vehicles to pass, and a second state in which the pedestrian traffic light does not allow pedestrians to pass and the vehicular traffic light allows vehicles to pass, based on a combination of the presence or absence of a moving object in the first area, the second area, and the third area. [Appendix 4] The control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state, there are no moving objects in the first area and the second area, and there is a moving object in the third area. The traffic light control device described in [Appendix 3]. [Appendix 5] The traffic light control device according to claim 3 or 4, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state, there is no moving object in the second area, and there is a moving object in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state a first time after the moving object has disappeared in the first area. [Appendix 6] The traffic light control device according to any one of Appendix 3 to Appendix 5, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state and a moving object is present in the third area, the state in which no moving object is present in the first area continues for a second time or more and the state in which a moving object is present in the second area continues for a third time or more. [Appendix 7] The second area includes a fourth area adjacent to the crosswalk and a fifth area located farther away from the crosswalk than the fourth area, and the third time is different between a case where a moving object is present in the fourth area and a case where a moving object is present in the fifth area and no moving object is present in the fourth area. [Appendix 8] The traffic light control device according to any one of appendixes 3 to 7, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state and a state in which a moving object is present in the third area continues for a fourth time period. [Appendix 9] The traffic light control device according to any one of appendixes 3 to 8, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the first state when a state in which the pedestrian traffic light and the vehicular traffic light are in the second state and no moving objects are present in the first area and the third area continues for a fifth time period. [Appendix 10] 10. The traffic light control device according to any one of claims 3 to 9, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the first state when the pedestrian traffic light and the vehicular traffic light are in the second state and the second state has continued for a sixth time period. [Appendix 11] The moving object includes a plurality of different types of moving objects including pedestrians, bicycles, and vehicles, and the control unit does not distinguish between the types of the moving objects. [Appendix 12] A traffic light control device according to any one of claims 1 to 11, wherein the communication unit acquires the detection result from a camera having a function of identifying a moving object from a captured image. [Appendix 13] A traffic light control method executed by a control unit of a traffic light control device, Obtaining detection results of moving objects detected in a plurality of detection target areas including a pedestrian crossing and surrounding the pedestrian crossing; Recognizing a combination of the presence or absence of the moving object for each of the plurality of regions based on the detection result; Controlling pedestrian and vehicular traffic lights based on the combination; and A traffic light control method comprising: [Appendix 14] The traffic light control method described in Appendix 13, wherein the control unit controls the pedestrian traffic light so that, when there is no moving object in any of the multiple areas, the pedestrian traffic light indicates that pedestrians are allowed to pass. [Appendix 15] The plurality of areas include a first area which is an area on the crosswalk, a second area which is an area of ​​a sidewalk adjacent to the crosswalk, and a third area which is an area through which vehicles heading toward the crosswalk pass, The traffic light control method described in Appendix 13 or 14, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition between a first state in which the pedestrian traffic light allows pedestrians to pass and the vehicular traffic light does not allow vehicles to pass, and a second state in which the pedestrian traffic light does not allow pedestrians to pass and the vehicular traffic light allows vehicles to pass, based on a combination of the presence or absence of a moving object in the first area, the second area, and the third area. [Appendix 16] The traffic light control method described in Appendix 15, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state, there are no moving objects in the first area and the second area, and there is a moving object in the third area. [Appendix 17] The traffic light control method described in Appendix 15 or 16, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state, there is no moving object in the second area, and there is a moving object in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state a first time after a moving object has disappeared in the first area. [Appendix 18] The traffic light control method according to any one of Appendix 15 to 17, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state and a moving object is present in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when a state in which no moving object is present in the first area continues for a second time or more and a state in which a moving object is present in the second area continues for a third time or more. [Appendix 19] The traffic light control method described in Appendix 18, wherein the second area includes a fourth area adjacent to the crosswalk and a fifth area located farther from the crosswalk than the fourth area, and the third time is different between a case where a moving object is present in the fourth area and a case where a moving object is present in the fifth area and no moving object is present in the fourth area. [Appendix 20] A pedestrian signal and a vehicle signal arranged to control traffic at a crosswalk; A detector for detecting moving objects in a plurality of detection target areas including the crosswalk and surrounding the crosswalk; a communication unit that acquires a detection result of a moving object detected by the detector, and a control unit that recognizes a combination of the presence or absence of the moving object for each of the plurality of areas based on the detection result, and controls the pedestrian traffic light and the vehicle traffic light based on the combination; A traffic light control system comprising: [Explanation of symbols]

[0074] 1. Traffic light control system 10 Signal control device 11 Communications Department 12 Control section 12 20A, 20B Detector 31 Pedestrian Traffic Lights 32 Vehicle Signals 41 Crosswalk 42 Pedestrians (moving objects) 43 Vehicles (mobile objects) 44 Pedestrian walkway 45 Vehicle Road 51 First Area (Crossing Area) 52 Second Area (Pedestrian Side Area) 53 Third Area (Vehicle Approach Area) 54 4th Area (Pedestrian Crossing Waiting Area) 55 5th Area (Crossing Pedestrian Approach Area)

Claims

1. A communication unit that acquires a detection result of detecting a moving object in a plurality of detection target areas including a crosswalk and surrounding the crosswalk; a control unit that recognizes a combination of the presence or absence of the moving object for each of the plurality of areas based on the detection results acquired by the communication unit, and controls a pedestrian traffic light and a vehicle traffic light based on the combination; A traffic light control device comprising:

2. The traffic light control device according to claim 1, wherein the control unit controls the pedestrian traffic light so that, when there is no moving object in any of the plurality of areas, the pedestrian traffic light indicates that pedestrians are allowed to pass.

3. The plurality of areas include a first area which is an area on the crosswalk, a second area which is an area where pedestrians near the crosswalk pass, and a third area which is an area where vehicles heading toward the crosswalk pass, 2. The traffic light control device according to claim 1, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition between a first state in which the pedestrian traffic light allows pedestrians to pass and the vehicular traffic light does not allow vehicles to pass, and a second state in which the pedestrian traffic light does not allow pedestrians to pass and the vehicular traffic light allows vehicles to pass, based on a combination of the presence or absence of a moving object in the first area, the second area, and the third area.

4. 4. The traffic light control device according to claim 3, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state, there are no moving objects in the first area and the second area, and there is a moving object in the third area.

5. 4. The traffic light control device according to claim 3, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state, there is no moving object in the second area, and there is a moving object in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state a first time after a moving object is no longer present in the first area.

6. 4. The traffic light control device according to claim 3, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state and a moving object is present in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when a state in which no moving object is present in the first area continues for a second time or more and a state in which a moving object is present in the second area continues for a third time or more.

7. 7. The traffic light control device according to claim 6, wherein the second area includes a fourth area adjacent to the crosswalk and a fifth area located farther from the crosswalk than the fourth area, and the third time is different when a moving object is present in the fourth area from when a moving object is present in the fifth area and when a moving object is not present in the fourth area.

8. 4. The traffic light control device according to claim 3, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state and a state in which a moving object is present in the third area continues for a fourth time period.

9. 4. The traffic light control device according to claim 3, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the first state when a state in which the pedestrian traffic light and the vehicular traffic light are in the second state and no moving objects are present in the first area and the third area continues for a fifth period of time.

10. 4. The traffic light control device according to claim 3, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the first state when the pedestrian traffic light and the vehicular traffic light are in the second state and the second state has continued for a sixth period of time.

11. The traffic light control device according to claim 1 , wherein the moving objects include a plurality of different types of moving objects including a pedestrian, a bicycle, and a vehicle, and the control unit does not distinguish between the types of the moving objects.

12. The traffic light control device according to claim 1 , wherein the communication unit acquires the detection result from a camera having a function of identifying a moving object from a captured image.

13. A traffic light control method executed by a control unit of a traffic light control device, Obtaining detection results of moving objects detected in a plurality of detection target areas including a pedestrian crossing and surrounding the pedestrian crossing; Recognizing a combination of the presence or absence of the moving object for each of the plurality of regions based on the detection result; Controlling pedestrian and vehicular traffic lights based on the combination; and A traffic light control method comprising:

14. The traffic light control method according to claim 13, wherein the control unit controls the pedestrian traffic light so that, when there is no moving object in any of the plurality of areas, the pedestrian traffic light indicates that pedestrians are allowed to pass.

15. The plurality of areas include a first area which is an area on the crosswalk, a second area which is an area of ​​a sidewalk adjacent to the crosswalk, and a third area which is an area through which vehicles heading toward the crosswalk pass, 14. The traffic light control method according to claim 13, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition between a first state in which the pedestrian traffic light allows pedestrians to pass and the vehicular traffic light does not allow vehicles to pass, and a second state in which the pedestrian traffic light does not allow pedestrians to pass and the vehicular traffic light allows vehicles to pass, based on a combination of the presence or absence of a moving object in the first area, the second area, and the third area.

16. 16. The traffic light control method according to claim 15, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when the pedestrian traffic light and the vehicular traffic light are in the first state, there is no moving object in the first area and the second area, and there is a moving object in the third area.

17. 16. The traffic light control method according to claim 15, wherein when the pedestrian traffic light and the vehicular traffic light are in the first state, there is no moving object in the second area, and there is a moving object in the third area, the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state a first time after a moving object is no longer present in the first area.

18. The traffic light control method according to claim 15, wherein the control unit controls the pedestrian traffic light and the vehicular traffic light to transition to the second state when, when the pedestrian traffic light and the vehicular traffic light are in the first state and a moving object is present in the third area, a state in which no moving object is present in the first area continues for a second time or more and a state in which a moving object is present in the second area continues for a third time or more.

19. 19. The traffic light control method according to claim 18, wherein the second area includes a fourth area adjacent to the crosswalk and a fifth area located farther from the crosswalk than the fourth area, and the third time is different between a case where a moving body is present in the fourth area and a case where a moving body is present in the fifth area but not in the fourth area.

20. A pedestrian signal and a vehicle signal arranged to control traffic at a crosswalk; A detector for detecting moving objects in a plurality of detection target areas including the crosswalk and surrounding the crosswalk; a communication unit that acquires a detection result of a moving object detected by the detector, and a control unit that recognizes a combination of the presence or absence of the moving object for each of the plurality of areas based on the detection result, and controls the pedestrian traffic light and the vehicle traffic light based on the combination; A traffic light control system comprising:

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