Traffic Control System

Abstract

To provide a traffic control system capable of controlling a lighting color state of a traffic light in order to obtain proper timing corresponding to the change of a traffic state even when the traffic state is changed.SOLUTION: A traffic control system 100 includes: a sensor processing unit 10 for acquiring information of a vehicle VE to pass a predetermined section IT to an intersection CS being an object position with a signal light SG (SG1); a time calculation unit TC for calculating an arrival predicted time to the intersection CS of the vehicle VE in response to the change of a traffic state obtained as the information of the vehicle VE; and a signal control unit 70 for controlling the lighting color state of the signal light SG (SG1) in response to the change of the arrival predicted time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a traffic control system that controls the color of traffic lights in accordance with traffic conditions. [Background technology]

[0002] For example, PTPS (Public Transportation Priority Systems) are being implemented to allow public vehicles such as buses to have priority passage, and are configured to control the color of traffic lights to extend the green light, etc. A system is known that takes into account left-turning vehicles at intersections, assuming the green light extension in such PTPS (see Patent Document 1).

[0003] However, the example of prior art 1 cannot necessarily appropriately deal with cases where the traffic situation changes between the time when the target vehicle (bus) is detected and the time when the target vehicle reaches the intersection. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-115249 Summary of the Invention

[0005] The present invention has been made in consideration of the above points, and aims to provide a traffic control system that can control the light color state of traffic lights so that it changes at an appropriate timing in response to changes in traffic conditions.

[0006] A traffic control system for achieving the above-mentioned objective comprises an information acquisition unit that acquires information about vehicles passing through a specified section leading up to a target location where a traffic light is installed, a time calculation unit that calculates the estimated time the vehicle will arrive at the target location in accordance with changes in the traffic conditions acquired as vehicle information, and a signal control unit that controls the light color state of the traffic light in accordance with changes in the estimated arrival time.

[0007] In the above traffic control system, the estimated arrival time is calculated according to changes in the traffic conditions of vehicles passing through a specified section, and the color state of the traffic lights is controlled according to the changes in the calculated estimated arrival time.This makes it possible to control the color state of the traffic lights so that the arrival time is appropriate in response to changes in the traffic conditions before the vehicle reaches the target location where the traffic light is installed (such as an intersection) and the arrival time becomes earlier or later than predicted when detection began.

[0008] In a specific aspect of the present invention, a specific vehicle priority unit is provided that, if the vehicle is a specific vehicle, requests the signal control unit to change the timing of the traffic light color of the traffic light based on the predicted arrival time calculated by the time calculation unit, and gives priority to the specific vehicle passing through the target position. In this case, it is possible to give priority to the specific vehicle passing through.

[0009] In another aspect of the present invention, the designated vehicle priority unit treats public transportation as a designated vehicle. In this case, public transportation such as a bus as a designated vehicle can be given priority to pass through.

[0010] In yet another aspect of the present invention, the information acquisition unit acquires information on changes in position and speed of the vehicle as vehicle information related to changes in traffic conditions. In this case, the estimated arrival time can be calculated based on the changes in position and speed of the vehicle.

[0011] In yet another aspect of the present invention, the information acquisition unit acquires image data of a predetermined section, in which case traffic conditions can be understood using the image data.

[0012] In yet another aspect of the present invention, an imaging unit is provided that continuously captures images of a predetermined section and generates image data, whereby changes in traffic conditions can be captured based on the continuous imaging.

[0013] In yet another aspect of the present invention, the information acquisition unit communicates with the vehicle and acquires communication data transmitted from the vehicle, thereby enabling calculation of the predicted arrival time based on the communication data. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a conceptual diagram for explaining an overview of a traffic control system according to a first embodiment. [Figure 2] FIG. 1 is a conceptual diagram for explaining vehicle detection by a traffic control system. [Figure 3] FIG. 1 is a block diagram showing an example of the configuration of a traffic control system. [Figure 4] FIG. 1 is a conceptual diagram showing an example of data transmission between parts of a traffic control system. [Figure 5] 1 is a data table showing an example of information relating to time handled in a traffic control system. [Figure 6] 10A to 10C are flowcharts illustrating an example of the operation of a traffic control system. [Figure 7] FIG. 2 is a sequence diagram for explaining the flow of processing between the components constituting the traffic control system. [Figure 8] FIG. 10 is a conceptual diagram for explaining an outline of a traffic control system according to a second embodiment. [Figure 9] FIG. 10 is a conceptual diagram for explaining an outline of a traffic control system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment] An example of a traffic control system according to the first embodiment will be described below with reference to FIG. 1 and other figures. FIG. 1 is a conceptual diagram outlining the traffic control system 100 according to this embodiment, FIG. 2 is a conceptual diagram illustrating vehicle detection by the traffic control system 100, and FIG. 3 is a block diagram showing an example configuration of the traffic control system 100. In this example, as shown in FIG. 1, the traffic control system 100 sets an intersection CS as the target location for traffic control, and controls the operation (signal switching control) of the signal lamps SG that are installed at the intersection CS and constitute traffic lights to regulate traffic for vehicles VE passing through the intersection CS. In particular, in this embodiment, when the traffic control system 100 detects a specific vehicle PT as a vehicle VE heading toward the intersection CS, it extends the time that the signal lamps SG display green to give the specific vehicle PT priority passing through the intersection CS. For this reason, the traffic control system 100 includes a sensor processing unit 10 that functions as an information acquisition unit that acquires information about the vehicle VE (specific vehicle PT), an information processing unit 50 that performs various processes on the information acquired by the sensor processing unit 10, and a signal control unit 70 that controls the signal of the signal lamp SG, i.e., manages and adjusts the time when the signal lamp SG is green, based on the processing by the information processing unit 50. Furthermore, in the above, it is assumed that a bus (a route bus), which is one form of public transportation, is treated as a specific vehicle PT that is given priority for passage. In other words, a case where the traffic control system 100 constitutes a PTPS (Public Transportation Priority Systems) will be described.

[0016] In the following, as shown by the area DA1 surrounded by a dashed line, a case will be described in which the traffic control system 100 performs signal control for one signal light SG1 among the signal lights SG installed at the intersection CS, but the traffic control system 100 can also perform signal control collectively for all (four) signal lights SG installed at the illustrated intersection CS, for example. Note that in Figure 1 etc., X, Y, and Z are right-handed Cartesian coordinate systems, with the +Z direction indicating the direction of travel on the road corresponding to the signal light SG1, the X direction indicating the left-right direction relative to the direction of travel, and the Y direction indicating the up-down direction.

[0017] First, the sensor processing unit 10 of the traffic control system 100 is connected to a sensor unit SE provided in the traffic light SG1 to be controlled (see FIG. 3 ). By operating the sensor unit SE, image data and distance measurement data of a vehicle VE approaching an intersection CS are acquired. As illustrated in the partially enlarged view of FIG. 1 and the example shown in FIG. 2 , the sensor unit SE is located close to the three light colors SGg, SGy, and SGr (blue, yellow, and red) that make up the traffic light SG1, i.e., at a certain height in the vertical direction (Y direction) relative to the traffic light SG1. As illustrated in the partially enlarged view of FIG. 1 , the sensor unit SE is comprised of a camera CA as an imaging unit that captures images and generates image data, a distance measurement unit DD that performs distance measurement and generates distance measurement data, and so on. It is possible to use a camera CA that captures images in the visible light wavelength band or an infrared light wavelength band. It is also possible to use a millimeter-wave sensor or radar, in addition to LiDAR, for the distance measurement unit DD. The camera CA and the distance measurement unit DD continuously capture (measure distances) images of a predetermined section IT on the road extending along the direction of travel (Z direction), generate image data and distance measurement data, and transmit various data to the sensor processing unit 10. Continuous imaging, etc., is performed at predetermined time intervals, for example, every 200 ms. This makes it possible to acquire information that captures changes in the position and speed of the vehicle VE traveling in the section IT. In other words, the sensor processing unit 10 can acquire changes in traffic conditions as information about the vehicle VE traveling in the section IT.

[0018] The sensor unit SE is provided in the signal lamp SG1 so as to include the section IT of the road that is the target of the signal aspect display at the signal lamp SG1 as the target section for sensing. In other words, the sensor processing unit 10 acquires information on vehicles passing through the section IT up to the intersection CS, which is the target position where the signal lamp SG1 is provided. The section IT is a section that has a predetermined length L on the upstream side of the stop line SS (the side away from the intersection CS), as shown in the example of FIG. 1. The length L can be, for example, about 100 m to 150 m.

[0019] As illustrated in FIG. 2, the sensor unit SE senses the vehicle VE present within the section IT. At this time, for example, by performing distance measurement, the sensor processing unit 10 can acquire information for grasping the position, size (height and length), shape, etc. of the vehicle VE to be detected, and the information processing unit 50 can analyze the vehicle type, etc. Note that information including the vehicle type, etc. can also be acquired by analyzing the image of the vehicle VE captured by the sensor unit SE in the information processing unit 50. Furthermore, in the above embodiment, for example, by performing continuous imaging, it is possible to capture changes in the traveling conditions of the vehicle VE (specific vehicle PT) within the section IT. Note that the image data obtained by imaging and the distance measurement data obtained by distance measurement may be combined to obtain the information necessary for performing each of the above-mentioned processes.

[0020] Returning to FIG. 1 , the information processing unit 50 of the traffic control system 100 analyzes, in a time calculation unit TC, information on changes in position and speed of the vehicle VE in the section IT acquired by the sensor processing unit 10, and predicts (estimates) the arrival time of the vehicle VE at the intersection CS. The information processing unit 50 also communicates with the signal control unit 70 to adjust signal control corresponding to the arrival time. The signal control unit 70 controls the operation of the signal lamp SG (SG1) in accordance with the content of communication with the information processing unit 50. That is, it performs processing such as extending the green display time. In particular, in the above-described embodiment, as described above, the sensor processing unit 10 constantly captures changes in the traveling conditions of the vehicle VE (specific vehicle PT) in the section IT. By performing processing in the information processing unit 50 accordingly, it is possible to constantly change the control mode of the signal control unit 70 in accordance with the traveling conditions.

[0021] Hereinafter, one operational mode of the above-described traffic control system 100 will be described with reference to Fig. 3 etc. The block diagram shown in Fig. 3 shows one configuration example of the traffic control system 100. As shown in the figure and as already described, the traffic control system 100 includes a sensor processing unit 10, an information processing unit 50, and a signal control unit 70.

[0022] The sensor processing unit 10 is an interface unit that connects to the sensor unit SE provided in the signal lamp SG (SG1) and transmits data to the information processing unit 50. That is, the sensor processing unit 10 acquires various data, including vehicle information, from the sensor unit SE. Here, the sensor processing unit 10 includes, as components for acquiring various data, an image data acquisition unit 10g that acquires image data captured by the sensor unit SE and a distance measurement data acquisition unit 10d that acquires distance measurement data by the sensor unit SE. With these components, the sensor processing unit 10 functions as an information acquisition unit that acquires information regarding the movement of a vehicle VE (particularly a specific vehicle PT) from the section IT to the intersection CS where the signal lamp SG (SG1) is installed. The various data acquired by the image data acquisition unit 10g and the distance measurement data acquisition unit 10d are transmitted (output) to the information processing unit 50. Note that the sensor processing unit 10 can also be considered to include the sensor unit SE in addition to the image data acquisition unit 10g and the distance measurement data acquisition unit 10d. That is, it can be considered that the camera CA, which is an imaging unit, and the distance measurement unit DD (see FIG. 1) constitute the sensor processing unit 10.

[0023] Furthermore, in order to enable various processes in the information processing unit 50, the sensor processing unit 10 has components for processing various data acquired about the vehicle VE, such as a vehicle type analysis unit (specific vehicle extraction unit) TA for extracting specific vehicles PT that should be prioritized from image data, etc., a vehicle position calculation unit PA for calculating changes in vehicle position from image data or ranging data, and a vehicle speed calculation unit VA for calculating changes in vehicle speed.

[0024] The vehicle type analysis unit (specific vehicle extraction unit) TA extracts (identifies) specific vehicles PT, i.e., buses (routed buses), from data related to vehicles VE contained in the image data and distance measurement data. Based on the results, an information processing unit 50 (described later) determines which vehicles VE are to be subjected to priority signal control.

[0025] The information processing unit 50 is configured, for example, by a PC having a CPU, a storage device, etc., various electronic circuits, etc. Here, the information processing unit 50 is configured by the PC or the like, including a main control unit 20 and a memory unit 30, and is connected to the sensor processing unit 10 and the signal control unit 70. The information processing unit 50 uses information about the vehicle VE transmitted from the sensor processing unit 10 to perform arithmetic processing in the main control unit 20 to enable signal control in accordance with changes in traffic conditions in the section IT leading up to the intersection CS. In addition, information from the sensor processing unit 10 and the processing contents in the main control unit 20 are stored in the memory unit 30.

[0026] First, the main control unit 20 of the information processing unit 50 is a specific vehicle priority unit that distinguishes the vehicle type, etc. of the vehicle VE and allows the specific vehicle PT to be treated preferentially, and is equipped with a time calculation unit TC that calculates the estimated arrival time of the vehicle VE (specific vehicle PT) at the intersection CS in accordance with changes in traffic conditions acquired as information about the vehicle VE (specific vehicle PT) by the vehicle type analysis unit (specific vehicle extraction unit) TA of the sensor processing unit 10, and an extension / reduction calculation unit ES that determines the extension or reduction of the green display of the signal lamp SG (SG1). As described above, when the vehicle VE is a specific vehicle PT, the main control unit 20 as the specific vehicle priority unit requests the signal control unit 70 to change the light color timing of the signal lamp SG based on the estimated arrival time calculated by the time calculation unit TC, and gives priority to the specific vehicle PT to pass through the intersection CS, which is the target location.

[0027] The time calculation unit TC predicts (predicts) the time it will take for the specific vehicle PT extracted by the vehicle type analysis unit TA of the sensor processing unit 10 to reach the intersection CS from its current position (number of seconds until bus arrival), i.e., the arrival time of the specific vehicle PT at the intersection CS, based on the changes in position and speed calculated by the vehicle position calculation unit PA and vehicle speed calculation unit VA of the sensor processing unit 10. Here, the prediction by the time calculation unit TC is subject to change each time as the position and speed of the specific vehicle PT change depending on traffic conditions.

[0028] The extension / shortening calculation unit ES receives information about the number of seconds until the bus arrives from the time calculation unit TC, and inquires about the remaining time for the green signal (number of seconds remaining for the green phase) from the signal control unit 70, which controls the operation of the signal lamp SG1, and calculates, from this information, the extension time for the green signal required for the specific vehicle PT to pass through the intersection CS. The calculated information about the extension time, etc. is transmitted (output) to the signal control unit 70.

[0029] The time calculation unit TC and extension / shortening calculation unit ES constituting the main control unit 20 may be provided as an integrated unit as the main control unit 20, or may be provided separately and independently so that they send and receive (transmit) the necessary information to each other.

[0030] Next, of the information processing unit 50, the memory unit 30 has an image data memory unit GM, a ranging data memory unit DM, a specific vehicle extraction data memory unit SD, a vehicle movement progress memory unit MM, an estimated arrival time memory unit EA, and an extension / shortening data memory unit AM.

[0031] The image data memory unit GM stores image data transmitted from the image data acquisition unit 10g of the sensor processing unit 10, and the ranging data memory unit DM stores ranging data transmitted from the ranging data acquisition unit 10d of the sensor processing unit 10.

[0032] The specific vehicle extraction data storage unit SD stores data related to the specific vehicle PT extracted by the vehicle type analysis unit (specific vehicle extraction unit) TA of the sensor processing unit 10. For example, information such as the vehicle type, shape, size, color, etc. of the specific vehicle PT is stored.

[0033] The vehicle movement progress memory unit MM stores, as vehicle movement progress, information on the vehicle position and speed that change from moment to moment, calculated by the vehicle position calculation unit PA and vehicle speed calculation unit VA of the sensor processing unit 10. The estimated arrival time memory unit EA also cumulatively stores, as vehicle movement progress, information on the estimated arrival time (number of seconds until bus arrival) of a specific vehicle PT at an intersection CS, which is calculated each time by the time calculation unit TC based on the information on the vehicle position and speed that change from moment to moment and stored in the vehicle movement progress memory unit MM.

[0034] The extension / reduction data storage unit AM cumulatively stores data history regarding inquiries to the signal control unit 70 from the extension / reduction calculation unit ES and transmission (output) of calculated extension times and the like to the signal control unit 70.

[0035] As described above, the information processing unit 50 calculates the estimated arrival time of the target vehicle based on the vehicle information acquired by the sensor processing unit 10, and transmits information such as the extension time of the green display at the signal light SG required for the calculated estimated time to the signal control unit 70.

[0036] The signal control unit 70 is configured, for example, by electronic circuits, etc., and is connected to the signal lamp SG (SG1), and controls the timing of switching the lighting (signal cycle) of each light color SGg, SGy, SGr (see FIG. 1) that constitutes the signal lamp SG. That is, it manages the phase stage map and, as necessary, shortens or extends (adjusts the display time) the green display time of the signal lamp SG1. That is, it updates (changes) the phase stage map. Particularly in this embodiment, the signal control unit 70 determines whether or not to extend or shorten the green display time based on information transmitted from the information processing unit 50, and controls the operation of the signal lamp SG according to the determination result. In order to perform the above signal control, the signal control unit 70 includes an indication seconds management unit 70m that manages the indication stage diagram of the signal lamp SG (SG1), an indication seconds update unit 70u that makes decisions regarding the extension or shortening of the green display time and updates the indication stage diagram, and a light color signal output unit 70o that outputs a command signal to switch the lights on and off to the signal lamp SG (SG1) according to the indication stage diagram.

[0037] Below, with reference to Figures 4 and 5, we will explain the information regarding data transmission and time handled between each part of the traffic control system 100 from the extraction of the specific vehicle PT, i.e., the detection of the bus, to the control of the timing of switching the display of the traffic light SG.

[0038] FIG. 4 conceptually shows an example of an overview when dividing various information processes into sections by processing content, focusing on the comings and goings of various times that are calculated or referenced during the various information processes.

[0039] First, the processing unit PP1 is configured by the sensor processing unit 10 and the information processing unit 50, or a part of them, and performs processing related to vehicle type detection (priority vehicle identification) to estimated arrival time (number of seconds until bus arrival) among the various processing performed by the sensor processing unit 10, the information processing unit 50, etc. As a result, the processing unit PP1 calculates the number of seconds until bus arrival Tb, which is transmitted to the processing unit PP2.

[0040] Next, the processing unit PP2 is configured by the information processing unit 50 or a part of the information processing unit 50. Among various processes, the processing unit PP2 performs processes related to extending or shortening the green signal time for a bus (specific vehicle PT) identified as a priority vehicle. To this end, the processing unit PP2 receives the bus arrival time Tb from the processing unit PP1 and also receives the remaining green signal time Tg, i.e., information on the remaining green signal time displayed on the signal lamp SG (SG1), from the signal control side, i.e., the signal control unit 70. Furthermore, the processing unit PP2 compares the acquired bus arrival time Tb with the remaining green signal time Tg and calculates the extension / reduction time Tex, i.e., the length of extension / reduction time required from the signal lamp SG (SG1) to allow the bus (specific vehicle PT) to pass. As a typical example, if the bus arrival time Tb is greater than the remaining green signal time Tg, the processing unit PP2 calculates the difference as the extension / reduction time Tex (>0), which is transmitted to the processing unit PP3. In the case described above, if the green light were not extended, the remaining green light seconds Tg would run out before the bus (special vehicle PT) reached the intersection CS, causing the signal to change from yellow to red.

[0041] Next, the processing unit PP3 is configured by the signal control unit 70 mentioned above, and among various processes, the processing unit PP3 performs processing related to signal control of the signal lamp SG (SG1). First, in response to a request from the processing unit PP2, the processing unit PP3 transmits (outputs) the remaining green phase seconds Tg to the processing unit PP2. The processing unit PP3 also receives the extension reduction seconds Tex transmitted from the processing unit PP2, and performs signal control based on the judgment result of the received extension reduction seconds Tex. Typically, a command signal is output from the light color signal output unit 70o of the signal control unit 70 to extend the green indication in accordance with the extension reduction seconds Tex.

[0042] The above-mentioned various times change from moment to moment. FIG. 5 is a data table showing examples of the above-mentioned various times, namely, the number of seconds until bus arrival Tb, the number of seconds remaining until green signal is displayed Tg, and the extension / reduction number of seconds Tex. In the data table, for example, the number of seconds until bus arrival Tb is calculated from the current position and speed of the bus (specific vehicle PT). Specifically, as described above, the time calculation unit TC of the information processing unit 50 calculates the position and traveling speed of the specific vehicle PT, and the number of seconds until bus arrival Tb is calculated based on these. As a typical example, the number of seconds until bus arrival Tb can be calculated by dividing the distance from the position of the specific vehicle PT to the intersection CS by the traveling speed of the specific vehicle PT. In other words, the number of seconds until bus arrival Tb (corresponding to the predicted arrival time) is the time until the arrival time of the specific vehicle PT at the intersection CS assuming that the current traveling speed of the specific vehicle PT is maintained constant. As described above, such calculation processing is repeatedly performed from the time when the bus (specific vehicle PT) is detected in the section IT until it reaches the intersection CS, that is, until it passes the stop line SS (see FIG. 1) which is the end of the section IT. In the illustrated example, the first detection time of the specific vehicle PT is T0, and the last detection time is T1. N In other words, the detection time T N indicates the detection result just before the bus (specific vehicle PT) passes the stop line SS, and the detection time T N+1indicates the detection result immediately after the bus (specific vehicle PT) passes the stop line SS. N+1 When it is confirmed that the bus (specific vehicle PT) indicated by has passed, all information regarding various times, including the number of seconds Tb until the bus arrives, is cleared, and the traffic control system 100 begins detecting a new bus (specific vehicle PT).

[0043] On the other hand, in the data table shown in Figure 5, the remaining seconds for green signal Tg (before update) is obtained from the signal control side, i.e., the signal control unit 70 or the processing unit PP3, but this is given to the information processing unit 50 or the processing unit PP2 as the value before processing to change (update) the green display time based on the extension / reduction seconds Tex described later.

[0044] 5, the extension / reduction seconds Tex is calculated based on the number of seconds until the bus arrives (Tb) and the number of seconds remaining until the green light turns green (Tg) (before updating). As a typical example, as described above and as shown in the figure, the extension / reduction seconds Tex can be calculated by subtracting the number of seconds remaining until the green light turns green (Tg) (before updating) from the number of seconds until the bus arrives (Tb). In other words, the difference between the remaining time for the green light in the current signal control unit 70 and the time until the bus reaches the intersection CS is used as the extension time, and the time sufficient for the bus (specific vehicle PT) to pass through the intersection CS is calculated.

[0045] In addition to the above-described cases, the extension / reduction time Tex can also be shortened, i.e., Tex = Tb - Tg (before update) < 0. A typical example of an extension (Tex > 0) is when traffic congestion (such as a jam) causes the specific vehicle PT to travel slower than normally expected in the section IT. However, if the traffic congestion (such as a jam) subsequently resolves, the specific vehicle PT's speed may increase again, reducing the value of the bus arrival time Tb. In such a case, the green light duration may be extended. However, from the perspective of overall traffic convenience, it is desirable to promptly change the traffic light for the specific vehicle PT, which is a priority vehicle, to red and change the traffic light for the other direction to green after the specific vehicle PT passes through the intersection CS. Therefore, in this embodiment, as an example, a shortening of the time is also possible, thereby maintaining smooth traffic flow.

[0046] Furthermore, in the data table shown in FIG. 5, the remaining seconds for green phase Tg (after update) can be calculated, as a typical example, by adding the extension / reduction seconds Tex calculated as described above to the remaining seconds for green phase Tg (before update). In other words, by setting the remaining seconds for green phase Tg (after update) obtained as described above as the new remaining time for green indication, sufficient time is ensured for the bus (specific vehicle PT) to pass through the intersection CS. However, the green indication time of the signal lamp SG (SG1) managed by the signal control unit 70 may be set to a minimum time for maintaining the green indication (e.g., the green indication time when switching according to a phase step diagram without extension) or a maximum time indicating the maximum extension limit. In such cases, updating the remaining seconds for green phase Tg that deviates from the minimum or maximum time is not selectable, and the signal control unit 70 will decide, for example, to maintain the remaining seconds for green phase Tg as it was before the update.

[0047] An example of the operation of the traffic control system 100 will be described below with reference to the flowchart in Fig. 6. Fig. 6(A) corresponds to the processing content in the processing unit PP1 in Fig. 4, Fig. 6(B) corresponds to the processing content in the processing unit PP2 in Fig. 4, and Fig. 6(C) corresponds to the processing content in the processing unit PP3 in Fig. 4.

[0048] First, as shown in Figure 6(A), as processing in the processing unit PP1, the main control unit 20 (specific vehicle priority unit) of the information processing unit 50 detects a bus (specific vehicle PT) based on data acquired by the sensor processing unit 10 (step S101).

[0049] In step S101, when a specific vehicle PT is detected (step S101: Yes), the time calculation unit TC of the main control unit 20 calculates the number of seconds Tb until the bus arrives (step S102), and this is sent to the processing unit PP2 (step S103), as shown by the dashed arrow.

[0050] After the transmission in step S103, the information processing unit 50 tracks the bus (specific vehicle PT) (step S104), and unless the bus (specific vehicle PT) has passed the stop line SS (step S105: No), the operations from step S102 onwards are repeated for the bus (specific vehicle PT). That is, detection of the next bus (specific vehicle PT) is started.

[0051] On the other hand, when it is confirmed that the bus (specific vehicle PT) has passed the stop line SS (step S105: Yes), the process returns to the operation from step S101, which is the initial process in processing unit PP1, and the above operation is repeated.

[0052] Next, as shown in FIG. 6(B), in the processing of processing unit PP2, first, extension / reduction calculation unit ES of main control unit 20 as processing unit PP2 waits for transmission of processing unit PP1 in step S103 (step S201). When bus arrival time Tb is received in step S201 (step S201: Yes), extension / reduction calculation unit ES inquires of signal control unit 70 as processing unit PP3 about the current remaining time Tg (before update), as indicated by the dashed arrow. That is, it requests the remaining time Tg (before update) (step S202), and waits until a reply is received (step S203). Note that the remaining time Tg at this time corresponds to the time before update, as described above.

[0053] In step S203, as shown by the dashed arrow, the processing unit PP3, i.e., the signal control unit 70, transmits the remaining seconds Tg for the green phase. When this is received (step S203: Yes), the extension / reduction calculation unit ES calculates the extension / reduction seconds Tex based on the bus arrival seconds Tb and the remaining seconds Tg for the green phase (before update) (step S204), and as shown by the dashed arrow, this is transmitted to the processing unit PP3 (step S205).

[0054] After the transmission shown in step S205, the processing section PP2 returns to the operation from step S201, which is the initial process, and repeats the above-mentioned operation. That is, the processing section PP2 waits for transmission from the next step S103.

[0055] Finally, as shown in Fig. 6(C), as processing in processing unit PP3, first, the signal control unit 70 as processing unit PP3 waits for a request (transmission) from processing unit PP2 in step S202 (step S301). In step S301, upon receiving a request for the remaining seconds Tg (before update) for green phase (step S301: Yes), information on the remaining seconds Tg for green phase (before update) is transmitted from the signal control unit 70m as indicated by the dashed arrow to processing unit PP2 (step S302). Thereafter, the signal control unit 70 as processing unit PP3 waits until the extension / reduction seconds Tex is transmitted from processing unit PP2 (step S303).

[0056] In step S303, as indicated by the dashed arrow, the processing unit PP2 transmits the extension / reduction seconds Tex. Upon receiving this (step S303: Yes), the signal control unit 70 as the processing unit PP3 determines whether the aspect seconds update unit 70u can update the remaining seconds Tg (before update) for green phase in accordance with the extension / reduction seconds Tex (step S304). If it is determined that this is possible (step S304: Yes), the aspect seconds update unit 70u updates the remaining seconds Tg (before update) for green phase to the new remaining seconds Tg (after update) = remaining seconds Tg (before update) + extension / reduction seconds Tex (step S305). In other words, the aspect step map managed by the aspect seconds management unit 70m is rewritten.

[0057] On the other hand, if it is determined in step S304 that updating is not possible (step S304: No), the green phase remaining seconds Tg is maintained as it was before updating, and the process ends.

[0058] When the above operation (step S305 or step S304: No) is completed, the processing returns to the operation from step S301, which is the initial process in the processing unit PP3, and the above operation is repeated. That is, the processing unit PP3 waits for a request in the next step S202.

[0059] As already described, the operations of the processing units PP1 to PP3 shown in the above flowcharts continue until one specific vehicle PT passes through the section IT.

[0060] FIG. 7 is a sequence diagram for explaining the flow of the above-mentioned processing between the components that make up the traffic control system 100, and particularly shows that the above-mentioned processing is repeatedly performed.

[0061] In the example of Figure 7, the sensor processing unit 10 and the time calculation unit TC of the main control unit 20 are shown as corresponding to processing unit PP1, the extension / shortening calculation unit ES of the main control unit 20 is shown as corresponding to processing unit PP2, and the signal control unit 70 is shown as corresponding to processing unit PP3.

[0062] First, the sensor processing unit 10 sends image data and ranging data as vehicle information to the main control unit 20 of the information processing unit 50, along with information regarding the vehicle's identification and its position and speed analyzed based on these.The main control unit 20 receives this information, and the time calculation unit TC calculates the number of seconds Tb for the bus to arrive, and the calculated number of seconds Tb for the bus to arrive is accepted by the extension / shortening calculation unit ES of the main control unit 20.

[0063] When the extension / reduction calculation unit ES receives the number of seconds until bus arrival Tb, it requests the number of seconds remaining for the green phase Tg (before updating) from the signal control unit 70, and when it receives this as a response from the signal control unit 70, it calculates the number of seconds until extension / reduction Tex from the number of seconds until bus arrival Tb and the number of seconds remaining for the green phase Tg (before updating) and sends this to the signal control unit 70.

[0064] When the signal control unit 70 receives the extension reduction seconds Tex, it updates the remaining green phase seconds Tg (before update) based on the received extension reduction seconds Tex, or it does not update it and maintains the state before the update.

[0065] The above series of operations is continuously performed at predetermined intervals Tx. That is, when the sensor processing unit 10 transmits the first vehicle information (image data, distance measurement data, vehicle identification, and information on the vehicle's position and speed) to the main control unit 20, the next vehicle information is transmitted after a certain time Tx (e.g., 200 ms), and this process is repeated. The information processing unit 50 and the signal control unit 70 perform the above series of processes for each transmission from the sensor processing unit 10. However, if the main control unit 20 determines from the analysis of the specific vehicle that there is no bus that is to be given priority, subsequent processes such as the process by the time calculation unit TC are omitted.

[0066] As described above, the traffic control system 100 according to this embodiment includes a sensor processing unit 10 that acquires information about the vehicle VE passing through a predetermined section IT leading up to the intersection CS, which is a target location where the signal lamp SG (SG1) is installed, a time calculation unit TC that calculates an estimated arrival time of the vehicle VE at the intersection CS in accordance with changes in traffic conditions acquired as information about the vehicle VE, and a signal control unit 70 that controls the light color state of the signal lamp SG in accordance with changes in the estimated arrival time. In this case, the traffic control system 100 calculates the estimated arrival time in accordance with changes in traffic conditions of the vehicle VE passing through the section IT, and controls the light color state of the signal lamp SG in accordance with changes in the calculated estimated arrival time. This makes it possible to control the light color state of the signal lamp SG (SG1) to appropriately time the arrival time, even if changes in traffic conditions cause the arrival time of the vehicle VE to be earlier or later than predicted at the start of detection, due to changes in traffic conditions while the vehicle VE is at the target location, such as the intersection CS, where the signal lamp SG is installed.

[0067] Second Embodiment An example of a traffic control system according to the second embodiment will be described below with reference to Fig. 8. The traffic control system 100 according to this embodiment is the same as that of the first embodiment except that the sensor processing unit 10 communicates with a vehicle VE (specific vehicle PT) and acquires communication data transmitted from the vehicle VE (specific vehicle PT). Therefore, a description of the overall configuration of the traffic control system 100 will be omitted.

[0068] FIG. 8 is a conceptual diagram showing an example configuration of a traffic control system 100 according to this embodiment, corresponding to FIG. 1. As shown in the figure, a specific vehicle PT, which is a vehicle VE, is equipped with a communication unit PTc, and communication data CC1 containing information enabling the specific vehicle PT to be identified is transmitted from the communication unit PTc. In this case, by receiving the communication data CC1 at the sensor processing unit 10, the traffic control system 100 can determine that the vehicle VE present in the section IT is a specific vehicle PT that should be treated with priority, and can then begin various necessary processes. In other words, the traffic control system 100 can calculate the estimated arrival time based on the communication data CC1.

[0069] In this embodiment as well, even if the traffic conditions change while the vehicle VE is approaching a target location such as an intersection CS, the light color state of the signal lamp SG can be controlled at an appropriate timing. In particular, in this embodiment, quick and accurate judgments can be made based on information acquired from the vehicle VE.

[0070] Third Embodiment An example of a traffic control system according to the third embodiment will be described below with reference to Fig. 9. The traffic control system 100 according to this embodiment processes a case where a plurality of specific vehicles PT (specified vehicles PTa and PTb) are approaching an intersection CS from different directions at one intersection CS. The overall configuration of the traffic control system 100 according to this embodiment is the same as that of the first embodiment, and therefore will not be described again.

[0071] In this embodiment, the traffic control system 100 performs signal control for both a signal lamp SG1, which is one of the signal lamps SG installed on a road along which a specific vehicle PTa travels toward the intersection CS from one direction, and a signal lamp SG2, which is one of the signal lamps SG installed on a road along which a specific vehicle PTb travels toward the intersection CS from the other direction, as shown by the area DA2 surrounded by a dashed line. In the illustration, the predetermined section IT corresponding to the signal lamp SG1 is referred to as section ITa, and the predetermined section IT corresponding to the signal lamp SG2 is referred to as section ITb. Furthermore, each of the signal lamps SG1 and SG2 is provided with a sensor unit SE, namely, sensor units SE1 and SE2, which perform sensing for the sections ITa and ITb.

[0072] In this embodiment, the traffic control system 100 may predetermine priorities for signal control of the signal lamp SG1 and signal control of the signal lamp SG2. For example, as shown in the figure, when a specific vehicle PTa (PT) is entering a section ITa (IT) and a specific vehicle PTb (PT) is entering a section ITb (IT), the specific vehicle PT that entered the section IT first may be given priority. Alternatively, when a specific vehicle PT is present in both sections ITa and ITb, the specific vehicle PT on the side indicated with a green light may be given priority. Furthermore, main and secondary lines may be predeterminable for roads, and the priority may be determined based on these lines. Alternatively, the priority may be determined based on the characteristics of the specific vehicle PT, i.e., a bus (routed bus). For example, the priority may be determined based on the route, or the traffic control system 100 may be linked to a bus operation system to grasp bus delays and determine the priority based on the delay status.

[0073] In this embodiment, even if the traffic conditions change while the vehicle VE is approaching a target location such as an intersection CS, the light color state of the signal lamp SG can be controlled at an appropriate timing. In particular, in this embodiment, appropriate judgment is possible when multiple buses are approaching from different directions.

[0074] 〔others〕 The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the present invention.

[0075] First, in the above example, the target vehicle VE was a bus, but this is not limited to this and various vehicles can be treated as specific vehicles PT. Furthermore, it is also possible to extend the green light for general vehicles.

[0076] In addition, although the above description has been made regarding the case where the green light is extended, it is also possible to shorten the red light. That is, if the red light is displayed when the specific vehicle PT is in the section IT, it is possible to shorten the display time so that the light changes to green by the time the specific vehicle PT reaches the intersection CS.

[0077] In the above description, the traffic control system 100 is configured to include a sensor processing unit 10, an information processing unit 50, and a signal control unit 70. In this configuration, for example, the signal control unit 70 may be configured by utilizing an existing signal control device and adding the sensor processing unit 10 and the information processing unit 50. More specifically, for example, as illustrated in Fig. 2, the traffic control system 100 may be configured by adding a housing CS1 that houses the sensor processing unit 10 and the information processing unit 50 to a housing CS2 that houses the signal control unit 70 as an existing signal control device, and connecting the various units as appropriate.

[0078] In addition, in the above explanation, in order to simplify the explanation, the time lag associated with communication time and calculation processing time is not taken into consideration, but it is also possible to perform judgment processing, etc. taking such time lag into account.

[0079] Also, for example, in the case described with reference to Figure 7, if the number of seconds until bus arrival Tb calculated by the time calculation unit TC does not change substantially when taking into account the passage of time, etc., and it is clear that there is no need to update the number of seconds remaining until green light Tg, operations subsequent to the calculation of the number of seconds until bus arrival Tb may be omitted.

[0080] It is also possible to configure the system so that the calculated number of seconds Tb for bus arrival is transmitted from the time calculation unit TC to the signal control unit 70, and the signal control unit 70 is then responsible for the necessary decision-making processes and the like.

[0081] Furthermore, when the signal control unit 70 updates the number of seconds remaining for the green phase Tg, it is also possible to notify the specific vehicle PT of the updated number of seconds remaining for the green phase Tg. For example, it is possible to adopt a configuration in which communication between the sensor processing unit 10 and the specific vehicle PT in the second embodiment is bidirectional, and the signal control unit 70 notifies the specific vehicle PT of the updated number of seconds remaining for the green phase Tg via the sensor processing unit 10.

[0082] Furthermore, in the above, the traffic control system 100 is configured to be composed of a sensor processing unit 10, an information processing unit 50, and a signal control unit 70, but the traffic control system 100 may also be configured by providing components corresponding to the processing units PP1 to PP3, as described with reference to Figure 4, for example.

[0083] Furthermore, in the above, the traffic control system 100 targets signal lights SG installed at intersections CS, but is not limited to this and can be applied to a variety of things, for example, it can be applied to signal control of BRT (Bus Rapid Transit) and LRT (Light Rail Transit) that run on routes other than general traffic routes.

[0084] Furthermore, the section IT for detecting the vehicle VE is not limited to the above example, and various other modes may be used.

[0085] In addition, in the above, as an example of continuous imaging by the sensor unit SE, imaging is performed at intervals of 200 ms, but an appropriate time interval can be set depending on the image processing performance, the minimum width (unit time) of green light adjustment in traffic light control, etc.

[0086] Furthermore, the sensor unit SE is attached to the signal lamp SG, and further, a combination of the camera CA and the distance measurement unit DD is shown as an example, but it is not limited to the above example, and various methods can be adopted as long as the necessary vehicle information can be acquired. For example, it is also possible to acquire all the necessary information from communication with the vehicle VE as exemplified in the second embodiment.

[0087] Furthermore, as explained above with reference to an example in Figure 1, the section IT is set to the upstream side of the stop line SS as the starting point, but sections of roads that are subject to traffic light phase display, such as the section IT, and sections that are subject to sensing are not limited to this, and for example, the section up to the point where the vehicle VE safely passes the intersection CS may be targeted, and the starting point of the section may be set at an appropriate position depending on the shape of the intersection CS.

[0088] Furthermore, in the above case, when the green light is extended at one intersection CS, in order to maintain synchronization with the signal control unit of an intersection adjacent to the intersection CS, it is possible to keep the cycle length unchanged by, for example, adjusting the green display time in the other direction based on the extended or shortened time in one direction of the intersection CS. [Explanation of symbols]

[0089] 10...sensor processing unit, 10d...distance measurement data acquisition unit, 10g...image data acquisition unit, 20...main control unit, 30...storage unit, 50...information processing unit, 70...signal control unit, 70m...aspect seconds management unit, 70o...light color signal output unit, 70u...aspect seconds update unit, 100...traffic control system, AM...extension / shortening data storage unit, CA...camera (imaging unit), CC1...communication data, CS...intersection, CS1, CS2...housing, DA1, DA2...range, DD...distance measurement unit, DM...distance measurement data storage unit, EA...estimated arrival time storage unit, ES...extension / shortening calculation unit, GM...image data storage unit, IT, I Ta, ITb...section, MM...vehicle movement progress memory unit, PA...vehicle position calculation unit, PP1 to PP3...processing unit, PT, PTa, PTb...specific vehicle (bus), PTc...communication unit, SD...specific vehicle extraction data memory unit, SE, SE1, SE2...sensor unit, SG, SG1, SG2...signal lamp, SGg, SGy, SGr...light color, SS...stop line, TA...vehicle type analysis unit (specific vehicle extraction unit), TC...time calculation unit, T0 to TN...detection time, Tb...bus arrival time in seconds, Tex...extension / reduction in seconds, Tg...remaining seconds for green phase, Tx...interval (time), VA...vehicle speed calculation unit, VE...vehicle

Claims

1. an information acquisition unit that acquires information on a vehicle passing through a predetermined section up to a target position where a traffic light is installed, such as information on changes in position, speed, size, and shape of the vehicle, based on distance measurements made by illuminating the vehicle approaching the target position from above using a distance measurement unit installed near a signal lamp that constitutes the traffic light; a specific vehicle extraction unit that analyzes the vehicle type from the size and shape of the vehicle determined by the distance measurement unit; a time calculation unit that calculates an estimated arrival time of the vehicle to the target position in accordance with a change in traffic conditions acquired from the vehicle information; a signal control unit that controls the light color state of the traffic light in response to a change in the predicted arrival time; A traffic control system comprising:

2. 2. The traffic control system according to claim 1, further comprising a specific vehicle priority unit that, if the vehicle is a specific vehicle, requests the signal control unit to change the light color timing of the traffic light based on the predicted arrival time calculated by the time calculation unit, and gives priority to the specific vehicle passing through the target position.

3. The traffic control system according to claim 2 , wherein the specific vehicle priority unit handles public transportation as the specific vehicle.

4. A traffic control system as described in any one of claims 2 and 3, wherein the specific vehicle extraction unit analyzes the vehicle type from the size and shape of the vehicle determined by distance measurement by the distance measurement unit, and extracts the specific vehicle.

5. 5. The traffic control system according to claim 1, wherein the information acquisition unit acquires information on changes in position and speed of the vehicle from distance measurement data obtained by continuous distance measurement by the distance measurement unit.

6. The traffic control system according to claim 5 , wherein the information acquisition unit acquires image data of the predetermined section in addition to the distance measurement data.

7. The traffic control system according to claim 6 , further comprising an imaging unit that continuously captures images of the predetermined section and generates the image data.

Images