Information providing device, information providing method, and computer program

Abstract

To provide signal information appropriately to a vehicle.SOLUTION: An information providing device includes a storage section that stores a signal control plan, an information processing section that generates signal information including first and second lamp colors and respective remaining time values based on the stored signal control plan, a communication section that transmits the generated signal information, and a lamp color monitoring section that monitors a lamp color of a traffic signal. At a time before an end of a variable step of the signal control plan, the information processing section applies a maximum value and a minimum value of a remaining time of the first lamp color to the signal information while leaving the values undetermined, and when the end of the variable step is detected based on a monitoring result of the lamp color monitoring section, the maximum value and the minimum value of the remaining time of the first lamp color are determined to be equal.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an information providing device, an information providing method, and a computer program. [Background technology]

[0002] Patent document 1 describes an information providing device that generates signal information including the current and future scheduled display times of signal lights based on a signal control plan executed by a traffic signal controller, and transmits the generated signal information to vehicles. The information providing device has a signal light color monitoring unit consisting of a current sensor, and transmits signal information at the cycle start time detected by the light color monitoring unit. For signal information after the cycle start time, the information providing device provides the signal information while subtracting the number of seconds of the currently displayed signal light color. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-39673 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 does not anticipate a method for providing appropriate signal information that ensures time continuity even when a signal control plan includes variable stages. In view of the above-mentioned problems, the present disclosure aims to provide an information providing device and the like that can provide appropriate signal information to vehicles. [Means for solving the problem]

[0005] An apparatus according to one embodiment of the present disclosure is an information providing apparatus including a memory unit that stores the following signal control plan, an information processing unit that generates signal information including the following first and second light colors and the remaining seconds thereof based on the stored signal control plan, a communication unit that transmits the generated signal information, and a light color monitoring unit that monitors the light colors of signal lamps, wherein at the start of the variable step of the signal control plan, the information processing unit applies the maximum and minimum values ​​of the remaining seconds for the first light color to the signal information without determining them, and when the information processing unit detects the end of the variable step based on the monitoring results of the light color monitoring unit, it determines the maximum and minimum values ​​of the remaining seconds for the first light color as the same value.

[0006] Signal control plan: Multiple levels, including variable levels, and data including duration of each level First light color: The signal light color of the vehicle lamp that is displayed at the initial time including the variable stage and at the fixed stage after the variable stage. Second light color: Signal light color of vehicle lighting equipment displayed after the first light color

[0007] A method according to one aspect of the present disclosure is an information provision method executed by an information provision device that includes a memory unit that stores the above-mentioned signal control plan, an information processing unit that generates signal information including the above-mentioned first and second light colors and their remaining seconds based on the stored signal control plan, a communication unit that transmits the generated signal information, and a light color monitoring unit that monitors the light colors of signal lamps, and includes the steps of: at the start of a variable step of the signal control plan, applying the maximum and minimum values ​​of the remaining seconds of the first light color to the signal information without determining them; and, when the end of the variable step is detected based on the monitoring results of the light color monitoring unit, determining the maximum and minimum values ​​of the remaining seconds of the first light color as the same value.

[0008] A computer program according to one embodiment of the present disclosure is a computer program that causes a computer to function as an information providing device that includes a memory unit that stores the above-mentioned signal control plan, an information processing unit that generates signal information including the above-mentioned first and second light colors and the remaining seconds thereof based on the stored signal control plan, a communication unit that transmits the generated signal information, and a light color monitoring unit that monitors the light colors of signal lamps, and includes the steps of: at the start of a variable step of the signal control plan, applying the maximum and minimum values ​​of the remaining seconds of the first light color to the signal information without determining them; and, when the end of the variable step is detected based on the monitoring results of the light color monitoring unit, determining the maximum and minimum values ​​of the remaining seconds of the first light color as the same value.

[0009] The present disclosure can be realized not only as a system and device having the above-described characteristic configuration, but also as a program for causing a computer to execute such characteristic configuration. Furthermore, the present disclosure can be realized as a semiconductor integrated circuit that realizes part or all of the system and device. [Effects of the Invention]

[0010] According to the present disclosure, appropriate signal information can be provided to vehicles. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing an example of the overall configuration of a traffic control system. [Figure 2] FIG. 2 is a road plan view showing an example of roadside devices around an intersection. [Figure 3] FIG. 3 is a plan view of a road showing another example of roadside devices around an intersection. [Figure 4] FIG. 4 is a block diagram showing an example of the internal configuration of the central device. [Figure 5] FIG. 5 is a block diagram showing an example of the internal configuration of a traffic signal controller. [Figure 6A] FIG. 6A is a schematic diagram showing an example of a connection configuration between an old controller and other communication nodes. [Figure 6B] FIG. 6B is a schematic diagram showing an example of a connection configuration between the new controller and other communication nodes. [Figure 7] FIG. 7 is a schematic diagram showing an example of a connection configuration between a roadside relay device and other communication nodes. [Figure 8] FIG. 8 is a block diagram showing an example of the internal configuration of a roadside repeater. [Figure 9] FIG. 9 is a diagram showing an example of a format of a signal control command. [Figure 10] FIG. 10 is a diagram showing an example of the format of the signal operation status information. [Figure 11] FIG. 11 is a table showing an example of a signal control plan created by a roadside repeater. [Figure 12A] FIG. 12A is a diagram showing the data structure of the signal information. [Figure 12B] FIG. 12B is an explanatory diagram showing the data values ​​and data contents stored in the header and data sections of the signal information. [Figure 13] FIG. 13 is a flowchart showing an example of a process for generating signal information. [Figure 14] FIG. 14 is an explanatory diagram showing an example of signal information output processing. DETAILED DESCRIPTION OF THE INVENTION

[0012] <Summary of Embodiments of the Present Disclosure> The following provides an outline of embodiments of the present disclosure. (1) The information providing device of this embodiment is an information providing device that includes a memory unit that stores the following signal control plan, an information processing unit that generates signal information including the following first and second light colors and the remaining seconds thereof based on the stored signal control plan, and a communication unit that transmits the generated signal information, wherein at the start of the variable step of the signal control plan, the information processing unit applies the maximum and minimum values ​​of the remaining seconds for the first light color to the signal information without determining them, and when it detects the end of the variable step, it determines the maximum and minimum values ​​of the remaining seconds for the first light color as the same value.

[0013] Signal control plan: Multiple levels, including variable levels, and data including duration of each level First light color: The signal light color of the vehicle lamp that is displayed at the initial time including the variable stage and at the fixed stage after the variable stage. Second light color: Signal light color of vehicle lighting equipment displayed after the first light color

[0014] According to the information providing device of this embodiment, at the start of the variable step of the signal control plan, the maximum and minimum values ​​of the remaining seconds for the first light color are applied to the signal information without being determined, and when the end of the variable step is detected, the maximum and minimum values ​​of the remaining seconds for the first light color are determined as the same value, so that the remaining seconds of the signal information provided do not suddenly increase or decrease. Therefore, even if the signal control plan includes variable steps, appropriate signal information with time continuity guaranteed can be provided.

[0015] (2) In the information providing device of this embodiment, for example, the first light color is a green light, and the second light color is a yellow light. In this case, the number of seconds remaining for the green light included in the traffic light information will not increase or decrease suddenly, so sudden or unnecessary deceleration due to entering a dilemma zone can be avoided.

[0016] (3) The information providing device of this embodiment comprises, for example, a roadside repeater that relays communication between a traffic signal controller and a central device that centrally controls the traffic signal controllers. In this case, by connecting a roadside repeater to a traffic signal controller (old controller) that does not have a communication interface for vehicles, it will be possible to provide signal information for vehicles even at intersections where old controllers are installed.

[0017] (4) In the information providing device of this embodiment, it is preferable that the information processing unit detects the end of the variable staircase based on the staircase number included in the execution staircase information received from the traffic signal controller. In this way, the end of the variable ladder can be detected without providing a light color monitoring unit, which will be described later.

[0018] (5) In the information providing device of this embodiment, if a light color monitoring unit is further provided that monitors the light color of the signal light device controlled by the traffic signal controller, the information processing unit may detect the end of the variable ladder based on the monitoring results of the light color monitoring unit. In this way, even if execution step information cannot be received from the traffic signal controller, the end of the variable step can be detected.

[0019] (6) The information providing device of this embodiment may be, for example, a traffic signal controller that is centrally controlled by a central device. In this case, the traffic signal controller, which is the main controller of the signal lights, generates the signal information, so more accurate signal information can be provided than when the roadside repeater generates the signal information.

[0020] (7) The information providing device of this embodiment may be, for example, a central device that centrally controls traffic signal controllers. In this case, the central device becomes the source of signal information, and therefore signal information relating to a plurality of traffic signal controllers managed by the central device can be provided to vehicles.

[0021] (8) The providing method of this embodiment relates to an information providing method executed by the information providing device described above in (1) to (7). Therefore, the providing method of this embodiment has the same effects as the information providing device of (1) to (7) above.

[0022] (9) The computer program of this embodiment relates to a computer program that causes a computer to function as the information providing device described above in (1) to (7). Therefore, the computer program of this embodiment has the same effects as the information providing devices (1) to (7) described above.

[0023] <Details of the embodiment of the present disclosure> Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. Note that at least some of the embodiments described below may be combined in any manner.

[0024] [Overall configuration of traffic control system] FIG. 1 is a perspective view showing the overall configuration of a traffic control system according to this embodiment. 1 shows, as an example, a traffic control system in which communication between a central device 6 and a traffic signal controller 12 is IP communication. As shown in FIG. 1, the traffic control system of this embodiment includes a traffic signal 1, a roadside sensor 2, a roadside communication device 3, a vehicle 5 equipped with an on-board communication device 4 (see FIGS. 2 and 3), and the central device 6. The vehicles 5 include vehicles that have on-board communication devices 4 that can communicate with the roadside communication devices 3, and vehicles that do not have on-board communication devices 4.

[0025] The traffic light 1 includes a plurality of signal lights 11 (only one of which is shown in Figure 1) that indicate whether or not right-of-way is available at each approach road at an intersection, and a traffic signal controller 12 that controls the timing of turning on and off the round lights, arrow lights, and other lights included in the signal lights 11. The traffic signal controller 12 is installed at each of a plurality of intersections Ji (i=1 to 12 in the illustrated example) included in the jurisdiction area of ​​the central device 6. The traffic signal controller 12 is connected to the router 7 via a dedicated communication line 8 such as a telephone line.

[0026] The router 7 is connected to a central device 6 in a traffic control center via a communication line 8. The central device 6 forms a LAN (Local Area Network) with the traffic signal controllers 12 at each intersection Ji included in the area under its jurisdiction. Therefore, the central unit 6 can communicate with the traffic signal controllers 12 within its jurisdiction, and the traffic signal controllers 12 can also communicate with the traffic signal controllers 12 at other intersections Ji. The central unit 6 may be installed on or along the road instead of in a traffic control center.

[0027] The roadside sensors 2 are installed at appropriate locations on roads within the jurisdiction area mainly for the purpose of counting the number of vehicles entering the intersection Ji. The roadside sensor 2 includes at least one of a vehicle detector that detects vehicles 5 passing directly below using ultrasonic waves or the like, a loop coil that detects vehicles 5 using changes in inductance, a surveillance camera that captures images of the traffic conditions of vehicles 5 in time series, and an optical beacon that performs optical communication with vehicles 5 using near-infrared rays. The roadside sensor 2 may also be a radio wave sensor such as a millimeter wave sensor or a Lidar sensor.

[0028] The roadside communication device 3 is, for example, a roadside wireless communication device compatible with ITS (Intelligent Transport Systems) wireless. The roadside communication device 3 is installed near one or more intersections Ji included in the jurisdiction area of ​​the central device 6. In the example of Figure 1, of the intersections J1 to J12 included in the jurisdiction area, roadside communication devices 3 are installed at some intersections J4 to J6, such as important intersections, and roadside communication devices 3 are not installed at the other intersections J1 to J3, J7 to J12.

[0029] The roadside communication device 3 can receive communication frames for vehicle-to-vehicle communication wirelessly conducted by the in-vehicle communication device 4 of a vehicle 5 traveling on the road, and can wirelessly transmit communication frames including information to be provided to the vehicle to the in-vehicle communication device 4. The roadside sensor 2 is connected to a traffic signal controller 12 via a dedicated communication line 9 (see Figures 2 and 3). The roadside communication device 3 is connected to the traffic signal controller 12 via a communication line 10 separate from the communication line 9 (see Figure 3).

[0030] The in-vehicle communication device 4 is, for example, a vehicle-side wireless communication device compatible with ITS wireless. Therefore, the in-vehicle communication device 4 can perform wireless communication (vehicle-to-vehicle communication) with other vehicles 5 traveling on the road, and can also receive communication frames including information to be provided to vehicles that are downlink transmitted by the roadside communication device 3. The in-vehicle communication device 4 may have an optical communication function for performing optical communication with the optical beacon using near-infrared rays in the communication area below the optical beacon.

[0031] The central device 6 is composed of one or more server computers owned by a traffic control company. The central device 6 collects sensor information measured by the roadside sensors 2, vehicle-to-vehicle communication information received from the vehicles 5 by the roadside communication devices 3 (hereinafter also referred to as "vehicle information"). The sensor information includes information detected by vehicle detectors (traffic volume and occupancy time) and beacon information received by an optical beacon from an optical communication-compatible in-vehicle communication device 4. The vehicle-to-vehicle communication information includes the vehicle ID, time, position, speed, etc. of the vehicle 5 that generated the information.

[0032] The central device 6 uses the collected various data to calculate traffic indices such as the inflow traffic volume per unit time to the intersection Ji. Based on the calculated traffic indices, the central device 6 performs traffic-responsive control (centralized control) for the intersection Ji that belongs to its jurisdiction area. The traffic response control of the central device 6 includes, for example, "system control" that controls a group of traffic signals at intersections Ji that belong to a specific system section, and "wide-area control (area control)" that extends system control to a road network.

[0033] In Japan, the control methods of the traffic signal controller 12 by the central device 6 are roughly classified into a "step control type" and a "table control type." The step control type is a method in which the central device 6 determines a signal control plan (e.g., Figure 11) that specifies the duration of each step of the signal lamp 11, and sends a control signal (step command) to the traffic signal controller 12 to command the turning on or off of a specified light color at the time when the step changes in the determined signal control plan.

[0034] The table control type is a method in which the central device 6 transmits a "signal control command" (see Figure 9), which is the original data for the signal control plan, to the traffic signal controller 12, and the traffic signal controller 12 determines a signal control plan (e.g., Figure 11) based on the received signal control command. The traffic signal controller 12 switches the display of the signal lamp 11 according to a signal control plan determined by itself. The signal control plan is determined for each cycle. The traffic control system of this embodiment is assumed to be compatible with a table control method.

[0035] When the central device 6 executes traffic-responsive control, it generates a signal control command including signal control parameters such as cycle, split, and offset. The central device 6 transmits the generated signal control command to the traffic signal controller 12 at the intersection Ji that is the control target.

[0036] The traffic signal controller 12 transmits signal control execution information indicating the control content executed in the previous cycle to the central device 6 at the start of the current cycle. The information stored in the signal control execution information includes the start time of the previous cycle (start time of the first step), the number of seconds for each step executed, the sensory execution type indicating the type of terminal sensory control executed, and vehicle detector detection information (traffic volume and occupancy time).

[0037] The traffic signal controller 12 transmits "signal operation status information" (see FIG. 10) indicating the operation status of the current cycle to the central device 6 at a cycle (for example, every second) shorter than the transmission cycle of the signal control execution information. The signal operation status information includes, for example, execution stage information including the current indication status and stage number, and operation status for notifying of operation abnormalities of the own device (such as timer abnormality or CPU abnormality). The execution stage information is always transmitted to the central device 6 at the timing when the stage progresses.

[0038] Although not shown in FIG. 1, when a roadside repeater 70 (see FIG. 8) is connected to the traffic signal controller 12 near the intersection Ji, the roadside repeater 70 is also included as a component of the traffic control system.

[0039] [Roadside devices around intersections] FIG. 2 is a road plan view showing an example of roadside devices around an intersection. The traffic signal controller 12 installed at the intersection J1 in FIG. 2 is a traffic signal controller 12A that does not have a communication interface for the roadside communication device 3 (hereinafter also referred to as the "old controller") . FIG. 3 is a plan view of a road showing another example of roadside devices around an intersection. The traffic signal controller 12 installed at the intersection J4 in FIG. 3 is a traffic signal controller (hereinafter also referred to as a "new controller") 12B having a communication interface for the roadside communication device 3.

[0040] When explaining matters common to both the old and new traffic signal controllers 12, the common symbol "12" is used. When explaining matters specific to the old controller, the symbol "12A" representing the old model is used, and when explaining matters specific to the new controller, the symbol "12B" representing the new model is used. 2 and 3, the roadside equipment at intersections J1 and J4 includes a traffic signal 1 and a roadside sensor 2. The traffic signal 1 includes a plurality of signal lamps 11 arranged for each incoming road, and a traffic signal controller 12 connected to each signal lamp 11 by a signal control line 13.

[0041] When the traffic signal controller 12 receives a signal control command from the central device 6, it determines the number of seconds for the offset tracking operation in accordance with the received signal control command, and determines the timing for switching the light color of the signal lamp 11 (centralized control). If the traffic signal controller 12 does not receive a signal control command from the central device 6, it performs periodic control to set a signal control plan according to the time period. At an intersection Ji where terminal-responsive control based on sensing information is performed, the traffic signal controller 12 may vary the variable steps included in the signal control plan within the range specified in the signal control command.

[0042] At intersection J1 in Fig. 2 and intersection J4 in Fig. 3, the roadside sensors 2 are connected to the traffic signal controller 12 via communication lines 9. Therefore, the traffic signal controller 12 has the function of relaying wired communication between the roadside sensors 2 and the central device 6. 3, the roadside communication device 3 is connected to the new controller 12B via a communication line 10 that is separate from the communication line 9. Therefore, the new controller 12B also has the function of relaying wired communication between the roadside communication device 3 and the central device 6.

[0043] At intersection J1 in Figure 2 and intersection J4 in Figure 3, the roadside sensors 2 transmit measured sensor information to the traffic signal controller 12. The traffic signal controller 12 transfers the sensor information received from the roadside sensors 2 to the central device 6. 3, the roadside communication device 3 is installed near the intersection J4 so as to be able to wirelessly communicate with vehicles 5 passing through an approach road to the intersection J4. Therefore, the roadside communication device 3 can receive a communication frame including vehicle information S1 transmitted and received by vehicle-to-vehicle communication.

[0044] When the roadside communication device 3 receives the vehicle information S1 from the in-vehicle communication device 4, it transmits the received vehicle information S1 to the new control device 12B. The new control device 12B transfers the vehicle information S1 received from the roadside communication device 3 to the central device 6. When the roadside communication device 3 receives the provision information S2 for vehicles from the traffic signal controller 12, the roadside communication device 3 generates a communication frame including the received provision information S2, and broadcasts the generated communication frame.

[0045] The information S2 provided for vehicles includes, for example, road congestion information, traffic regulation information, and road alignment information near the intersection Ji. If the new controller 12B is compatible with the DSSS (Driving Safety Support System), the new controller 12B can output traffic light information (see FIG. 12) as information S2 to be provided to vehicles to the roadside communication device 3. The traffic light information is information that indicates the planned display time of the traffic light device 11 from the current time onward, and includes, for example, the planned number of seconds (remaining seconds) for displaying each light color on each incoming road.

[0046] [Internal configuration of the central device] FIG. 4 is a block diagram showing an example of the internal configuration of the central device 6. As shown in FIG. As shown in FIG. 4, the central device 6 includes a control unit (information processing unit) 61, a display unit 62, a communication unit 63, a storage unit 64, and an operation unit 65. The control unit 61 of the central device 6 comprehensively collects, processes (calculates), and records various types of information, controls traffic signals, and provides information. The control unit 61 is connected to each hardware unit via an internal bus and also controls the operation of each unit.

[0047] The control unit 61 of the central device 6 is made up of an arithmetic processing device including a CPU (Central Processing Unit) and a main memory made up of a RAM (Random Access Memory). The CPU of the control unit 61 reads the computer program stored in the storage unit 64 into the main memory and performs various information processing in accordance with the program. The control unit 61 may include integrated circuits such as an FPGA (Field-Programmable Gate Array) and an ASIC (Application Specific Integrated Circuit).

[0048] The control unit 61 of the central device 6 executes the above-mentioned system control and wide-area control (area control). Specifically, the control unit 61 performs traffic-responsive control to set signal control parameters (split, cycle length, and offset) for each intersection Ji based on traffic indicators (e.g., inflow traffic volume) calculated from collected sensor information, etc.

[0049] The communication unit 63 of the central device 6 includes a communication interface and is connected to roadside devices other than the central device itself via a communication line 8. The communication unit 63 transmits signal control commands generated at each predetermined control period and traffic information such as congestion information and regulation information to each traffic signal controller 12. The signal control commands are transmitted at each control period (e.g., 1.0 to 2.5 minutes) of the signal control parameters, and the traffic information is transmitted, for example, every 5 minutes.

[0050] The communication unit 63 of the central device 6 can receive the vehicle ID, location information, and speed information of the vehicle 5 having the on-board communication device 4, as well as the detection signal of the roadside sensor 2 consisting of a vehicle detector, from the traffic signal controller 12 in almost real time (for example, at a cycle of 0.1 to 1.0 seconds).

[0051] The storage unit 64 of the central device 6 is composed of a hard disk, a semiconductor memory, etc. The storage unit 64 stores a control program for traffic response control, a calculation program for signal control parameters used in traffic response control, etc. The storage unit 64 of the central device 6 temporarily stores the signal control command and traffic information generated by the control unit 61, as well as the vehicle ID, position information, speed information, and sensing signal acquired from the LAN side.

[0052] The display unit 62 of the central device 6 is composed of one or more liquid crystal displays, etc. The display unit 62 is capable of displaying a road map of the management area. The road map displayed on the display unit 62 includes icons representing the traffic signals 1 and roadside sensors 2 within the jurisdiction area. The operation unit 65 of the central device 6 includes an input interface such as a keyboard and a mouse. An operator at the traffic control center can switch the screen displayed on the display unit 62 by inputting operations into the operation unit 65.

[0053] [Internal structure of a traffic signal controller] FIG. 5 is a block diagram showing an example of the internal configuration of the traffic signal controller 12. As shown in FIG. 5, the traffic signal controller 12 includes a control unit (information processing unit) 21, a light unit driving unit 22, a communication unit 23, and a memory unit 24. The control unit 21 is connected to the light unit driving unit 22, the communication unit 23, and the memory unit 24 via an internal bus.

[0054] The control unit 21 of the traffic signal controller 12 is made up of a processing unit including a CPU and a main memory made up of RAM. The CPU of the control unit 21 reads out the computer program stored in the storage unit 24 into the main memory and performs various information processing in accordance with the program. The control unit 21 may include an integrated circuit such as an FPGA or an ASIC.

[0055] The control unit 21 of the traffic signal controller 12 creates a signal control plan based on the signal control parameters included in the signal control command generated by the central device 6. Based on the created signal control plan, the control unit 21 generates control signals (step signals) that turn on / off each signal light that makes up the signal light unit 11, and outputs the generated control signals to the light unit drive unit 22.

[0056] The lamp driving unit 22 is connected to the signal lamp 11 by a signal control line 13 (see Figures 2 and 3) including a power line. The lamp driving unit 22 includes a semiconductor relay (not shown) that switches the signal lamp color of the signal lamp 11 in response to a control signal input from the control unit 21. Specifically, the lamp driving unit 22 turns on / off the AC voltage or DC voltage supplied to each signal lamp, such as blue, yellow, and red, included in the signal lamp unit 11 in accordance with a control signal input from the control unit 21.

[0057] The communication unit 23 of the traffic signal controller 12 has a communication interface for performing wired communication with the central device 6 and a communication interface for performing wired communication with the roadside sensor 2. When the communication unit 23 of the traffic signal controller 12 receives a signal control command generated by the central device 6, it outputs the received signal control command to the control unit 21. When signal control execution information or signal operation status information is input from the control unit 21, the communication unit 23 transmits the input information to the central device 6. When the communication unit 23 receives sensor information from the roadside sensor 2, it transfers the received sensor information to the central device 6.

[0058] When the traffic signal controller 12 is the new controller 12B, the communication unit 23 further includes a communication interface for performing wired communication with the roadside communication device 3. Therefore, when the communication unit 23 of the new control device 12B receives provided information S1 for vehicles, such as traffic congestion information, from the central device 6, it transfers the received information to the roadside communication device 3. In addition, when the communication unit 23 receives vehicle information from the roadside communication device 3, it transfers the received vehicle information to the central device 6.

[0059] The storage unit 24 of the traffic signal controller 12 is composed of a hard disk, a semiconductor memory, etc. The storage unit 24 stores various computer programs that the control unit 21 executes. The computer programs stored in the storage unit 24 include a communication control program for relaying various received data, such as signal control commands, traffic information, sensor information, and vehicle information, to appropriate destinations.

[0060] If the traffic signal controller 12 is a new controller 12B that is DSSS compatible, the computer programs stored in the memory unit 24 include a program for causing the control unit 21 to execute a "process for generating signal information" for vehicles. The process of generating signal information performed by the traffic signal controller 12B is almost the same as the process of generating signal information performed by a roadside repeater 70 (see FIG. 8) described later. Therefore, the process of generating signal information will be described in detail later.

[0061] When the control unit 21 of the new control device 12B generates the signal information for the vehicle, it outputs the generated signal information to the communication unit 23. The communication unit 23 of the new controller 12B transmits the input signal information to the roadside communication device 3. The roadside communication device 3 broadcasts a communication frame including the received signal information to the vehicles 5 at a predetermined transmission period (for example, 100 ms).

[0062] [Traffic control system issues and solutions] FIG. 6A is a schematic diagram showing a connection configuration between the old controller 12A and other communication nodes. The old controller 12A does not have a communication interface for the roadside communication device 3. Therefore, as shown in Fig. 6A, the old controller 12A is connected to a communication line 8 leading to the central device 6 and a signal control line 13 leading to a signal light device 11.

[0063] FIG. 6B is a schematic diagram showing the connection configuration between the new controller 12B and other communication nodes. The new controller 12B has a communication interface for the roadside communication device 3. Therefore, as shown in Fig. 6B, the new controller 12B is connected to a communication line 8 leading to the central device 6, a signal control line 13 leading to the signal lamp 11, and a communication line 10 leading to the roadside communication device 3.

[0064] In DSSS applications, the traffic light information generated by the new controller 12B is provided to the vehicle 5 by the ITS wireless compatible roadside communication device 3. Therefore, the driver of the vehicle 5 can quickly determine whether or not to pass through the intersection Ji that he or she plans to pass, based on the received traffic light information, and can drive safely and smoothly.

[0065] If the vehicle 5 is an autonomous vehicle, the accuracy of recognizing the signal light color can be improved by comparing the current signal light color sensed by the on-board sensor with the signal information provided by the infrastructure. Assuming that the provision of traffic light information is useful for automated driving, it is preferable to provide the vehicle 5 with traffic light information for all intersections Ji included in the route of the vehicle 5 performing automated driving.

[0066] In the traffic control system of Figure 1, if the old controllers 12A at intersections J1 to J3 and J7 to J12 are replaced with new controllers 12B, or if the old controllers 12A are modified so that they can communicate with the roadside communication devices 3, a system for providing traffic light information useful to autonomous vehicles can be constructed. However, for example, in Japan, the majority of traffic signal controllers 12 are old controllers 12A that do not have a communication interface for roadside communication devices 3, so replacing or modifying all of the old controllers 12A is not realistic from a cost perspective.

[0067] Furthermore, the replacement cycle for traffic signal controllers 12 is about 20 years, and updating takes a long time, making it difficult to quickly popularize information provision services for autonomous driving. Meanwhile, the use of cellular communications such as the fifth generation mobile communications system (5G) is being considered as a communication system for wirelessly providing information to vehicles. However, since the traffic signal controller 12 does not have a communication interface for communicating with a base station, in any case, the traffic signal controller 12 will need to be replaced or modified.

[0068] The roadside repeater device (hereinafter also referred to as "signal conversion adapter") 70 of this embodiment is a device for solving the above-mentioned problems. The roadside repeater device 70 has the following functions 1 to 3. It is a repeater device.

[0069] Function 1: Function of relaying communication between the central device 6 and the traffic signal controller 12A Function 2: A function of generating signal information for vehicles using a control command (e.g., a signal control command) for controlling the traffic signal controller 12A generated by the central device 6 and the control content (e.g., signal operation status information) executed by the traffic signal controller 12A based on the control command. Function 3: A function of communicating with a communication device 30 that belongs to a communication system that provides signal information wirelessly (for example, an ITS wireless system or a mobile communication system).

[0070] FIG. 7 is a schematic diagram showing an example of a connection configuration between the roadside repeater 70 and other communication nodes. As shown in Figure 7, a roadside repeater (signal conversion adapter) 70 is connected to a communication line 8 which is a transmission line for a central device 6, a communication line 9 which is a transmission line for a traffic signal controller 12A, and a communication line (e.g., a serial communication line, a LAN cable, or an optical line) 10 which is a transmission line for a vehicle-oriented communication device 30.

[0071] A router 7 or a relay device capable of protocol conversion may be interposed in the communication path between the signal conversion adapter 70 and the central device 6. Similarly, a relay device such as a LAN switch or a media converter may be interposed in the communication path between the signal conversion adapter 70 and the communication device 30.

[0072] The signal conversion adapter 70 has a first communication interface to which a communication line (first line) 8 is connected, a second communication interface to which a communication line (second line) 9 is connected, and a third communication interface to which a communication line (third line) 10 is connected. The signal conversion adapter 70 has the function of converting and relaying the communication protocol between the communication lines 8 and 9. Therefore, the signal conversion adapter 70 behaves as the traffic signal controller 12A to the central unit 6, and as the central unit 6 to the traffic signal controller 12A.

[0073] If the first and second communication interfaces are of the same communication standard (for example, UD transmission system), protocol conversion between the two communication interfaces is not necessary, and the same type of communication line is used for the communication lines 8 and 9.

[0074] The signal conversion adapter 70 relays downstream frames sent by the central device 6 to the traffic signal controller 12A and upstream frames sent by the traffic signal controller 12A to the central device 6, and can therefore extract information contained in these communication frames. Therefore, the signal conversion adapter 70 generates signal information for vehicles based on information (such as a signal control command) included in the communication frame. That is, the signal conversion adapter 70 also functions as an information providing device that generates and outputs signal information for vehicles.

[0075] The signal conversion adapter 70 transmits the generated signal information to the communication device 30. The communication device 30 is, for example, an ITS radio device (roadside communication device 3) or a base station for cellular communication. If the communication device 30 is an ITS radio, the ITS radio wirelessly transmits the signal information to the in-vehicle communication device 4 of the vehicle 5. If the communication device 30 is a base station, the signal information is transferred from the base station to a cloud server of the core network. The cloud server transfers the signal information to the same or a different base station, and the base station wirelessly transmits the signal information to the mobile terminal of the vehicle 5.

[0076] [Internal configuration of roadside repeater] FIG. 8 is a block diagram showing an example of the internal configuration of the roadside repeater 70. As shown in FIG. As shown in Figure 8, the roadside repeater device 70 includes an upper communication unit 71, a traffic light communication unit 72, a vehicle communication unit 73, a communication processing unit 74, an information processing unit 75, a synchronization processing unit 76, a memory 77, and a light color monitoring unit 78.

[0077] The upper communication unit 71 is a communication interface that transmits and receives electrical signals in accordance with a predetermined transmission method (communication protocol) to and from the central device 6. Here, the transmission method of the central device 6 is assumed to be, for example, a "UD type transmission method" that enables IP communication. The upper communication unit (first communication unit) 71 is connected to a communication line (first line) 8 used for wired communication with the central device 6.

[0078] The upper side communication unit 71 demodulates the electric signal (carrier signal) input from the communication line 8 to reproduce a downstream frame. The upper side communication unit 71 outputs the reproduced downstream frame to the communication processing unit 74. The upper communication unit 71 modulates the upstream frame input from the communication processing unit 74 into an electric signal (carrier signal) of a predetermined frequency. The upper communication unit 71 sends the modulated electric signal (carrier signal) to the communication line 8.

[0079] The traffic light communication unit 72 is a communication interface that transmits and receives electrical signals in accordance with a predetermined transmission method to and from the traffic signal controller 12A. Here, the transmission method of the traffic signal controller 12A is assumed to be, for example, a "U-type transmission method" that does not support IP communication. The traffic light side communication unit (second communication unit) 72 is connected to a communication line (second line) 9 used for wired communication with the traffic signal controller 12A.

[0080] The traffic light communication unit 72 demodulates the electrical signal (carrier signal) input from the communication line 9 to reproduce the upstream frame. The traffic light communication unit 72 outputs the reproduced upstream frame to the communication processing unit 74. The traffic light communication unit 72 modulates the downstream frame input from the communication processing unit 74 into an electrical signal (carrier signal) of a predetermined frequency. The traffic light communication unit 72 sends the modulated electrical signal (carrier signal) to the communication line 9.

[0081] The vehicle-side communication unit 73 is a communication interface that transmits and receives electrical signals in accordance with a predetermined communication protocol to and from the communication device 30. The transmission method of the communication device 30 may be, for example, a high-speed serial transmission method or a transmission method that enables IP communication, such as a wired LAN. A communication line (third line: for example, a serial cable or an Ethernet cable) 10 is connected to the vehicle-side communication unit (third communication unit) 73. The communication line (third line) 10 is used for wired communication between the roadside repeater 70 and the communication unit 30. The communication unit 30 belongs to a communication system that provides information to the vehicle 5 wirelessly.

[0082] The vehicle-side communication unit 73 demodulates the electrical signal (carrier signal) received from the communication line 10 to reproduce the upstream frame. The vehicle-side communication unit 73 outputs the reproduced upstream frame to the communication processing unit 74. The vehicle-side communication unit 73 modulates the downstream frame input from the communication processing unit 74 into an electric signal (carrier signal) of a predetermined frequency. The vehicle-side communication unit 73 transmits the modulated electric signal (carrier signal) to the communication line 10.

[0083] When the communication device 30 is a base station using an optical line, the vehicle-side communication unit 73 is configured by an optical transceiver. In this case, the processing contents of the vehicle-side communication unit 73 are as follows. The vehicle-side communication unit 73 converts the optical signal input from the optical fiber (third line) 10 into an electrical signal to regenerate the upstream frame. The vehicle-side communication unit 73 outputs the converted upstream frame to the communication processing unit 74. The vehicle-side communication unit 73 converts the downstream frame input from the communication processing unit 74 into an optical signal of a predetermined wavelength. The vehicle-side communication unit 73 transmits the converted optical signal to the optical fiber 10.

[0084] The communication processing unit 74, the information processing unit 75, the synchronization processing unit 76, the memory 77, and the light color monitoring unit 78 are functional parts of a processing unit including, for example, a CPU and a RAM. The CPU of the arithmetic processing device reads a computer program installed in a storage device (not shown) into the main memory (RAM) and performs various information processing in accordance with the program. The arithmetic processing device can be configured with one or more integrated circuits such as FPGAs and ASICs other than or in addition to the CPU.

[0085] The communication processing unit 74 relays communication frames transmitted and received between the central device 6 and the traffic signal controller 12A after performing a predetermined protocol conversion. Specifically, the communication processing unit 74 converts a downstream frame of the UD type transmission method input from the upper side communication unit 71 into a format of the U type transmission method, and outputs the converted downstream frame to the traffic light side communication unit 72. Conversely, the communication processing unit 74 converts an upstream frame of the U type transmission method input from the traffic light side communication unit 72 into a format of the UD type transmission method, and outputs the converted upstream frame to the upper side communication unit 71.

[0086] If the downstream frame input from the upper communication unit 71 contains a signal control command, the communication processing unit 74 extracts the signal control command from the downstream frame and temporarily stores the extracted signal control command in the memory 77. If the upstream frame input from the traffic light side communication unit 72 contains signal operation status information, the communication processing unit 74 extracts the information from the upstream frame and temporarily stores the extracted information in the memory 77.

[0087] In addition, if there is information required for generating and processing signal information that is not transmitted and received through communication between the central device 6 and the traffic signal controller 12A (such as the number of floors included in one cycle, the correspondence between floor numbers and the light colors of each entrance road, which is implicitly set between the two devices), it can be permanently stored in memory 77 by manual setting, etc.

[0088] The communication processing unit 74 relays communication frames transmitted and received between the central device 6 and the communication device 30 after performing a predetermined protocol conversion. Specifically, the communication processing unit 74 converts a downstream frame of the UD transmission method input from the upper communication unit 71 into a format of the transmission method adopted by the communication device 30, and outputs the converted downstream frame to the vehicle-side communication unit 73. Conversely, the communication processing unit 74 converts an upstream frame of the transmission method adopted by the communication device 30 input from the vehicle-side communication unit 73 into a format of the UD transmission method, and outputs the converted upstream frame to the upper communication unit 71.

[0089] The information provided by the central device 6 to the communication device 30 via the downstream frame includes, for example, traffic information such as congestion information or regulation information. The information provided by the communication device 30 to the central device 6 through the upstream frame includes, for example, inter-vehicle communication information generated by the vehicle 5.

[0090] The information processing unit 75 can detect the current control state of the traffic signal controller 12A based on the signal control command and signal operation state information stored in the memory 77. For example, the information processing unit 75 can create a signal control plan based on signal control parameters (cycle, split, offset, etc.) included in the signal control command. The information processing unit 75 can also determine whether the traffic signal controller 12A is executing terminal sensitive control based on the type of terminal sensitive control specified in the signal control command.

[0091] The information processing unit 75 generates traffic light information for vehicles based on the created traffic light control plan. The details of the "traffic light information generation process" performed by the information processing unit 75 will be described later. When the information processing unit 75 generates the signal information for the vehicle, it generates a downlink frame including the generated signal information and outputs the generated downlink frame to the vehicle-side communication unit 73. The vehicle-side communication unit 73 transmits the downlink frame including the input signal information to the communication device 30.

[0092] The synchronization processing unit 76 is a processing unit for achieving time synchronization with other communication nodes such as the central device 6 using a predetermined synchronization method. The synchronization method of the synchronization processing unit 76 may be, for example, GPS synchronization, which synchronizes the time with a 1PPS (Pulse Per Second) signal acquired by a GPS (Global Positioning System) receiver, or a synchronization method using communication frames such as NTP (Network Time Protocol) and PTP (Precision Time Protocol).

[0093] The communication processing unit 74 determines the timing of transmitting communication frames according to the local time generated by the synchronization processing unit 76 . The information processing unit 75 determines the cycle start time TS (see FIG. 11) of the created signal control plan in accordance with the local time generated by the synchronization processing unit 76.

[0094] The light color monitoring unit 78 is connected to a light color sensor 79. The light color sensor 79 is made up of, for example, an ammeter that detects the current flowing from the light device driving unit 22 to the signal light device 11. The light color monitoring unit 78 determines the current light color of the signal light device 11 based on the current value detected by the light color sensor 79. For example, the light color monitoring unit 78 determines the current light color to be red while the current to the red signal light is on. The same applies to other light colors.

[0095] The light color sensor 79 may be an image sensor (for example, a CCD camera) capable of capturing video. In this case, the light color monitoring unit 78 determines the current light color of the signal light unit 11 based on the RGB values ​​of the light unit part included in the image data input from the light color sensor 79. The light color monitoring unit 78 outputs the determination result of the current light color to the information processing unit 75. The information processing unit 75 uses the determination result of the current light color to determine the end of the variable ladder, determine whether there is an operational abnormality in the traffic signal controller 12A, and the like.

[0096] For example, in the signal control plan of FIG. 11, if 1PG is a variable step, the signal processor 75 can determine the end of 1PF when the pedestrian light starts flashing green. Furthermore, if an abnormality in the transition state of the current light color (such as green lights in both the east-west direction and the north-south direction) is detected, the information processing unit 75 may notify the central unit 6. Specifically, the information processing unit 75 generates a communication frame addressed to the central unit 6, which includes the identification information of the traffic signal controller 12A and the details of the abnormality, and outputs the generated communication frame to the communication processing unit 74.

[0097] [Signal control command and signal operation status information format] Fig. 9 is a diagram showing an example of a format of a signal control command, and Fig. 10 is a diagram showing an example of a format of signal operation status information. The formats shown in Figures 9 and 10 are specified in the "U-type Traffic Signal Controller U-type Communication Application Standard" published by the Universal Transport Management System (UTMS) Society. Therefore, the data content included in the formats shown in Figures 9 and 10 is described in the standard.

[0098] For example, as shown in FIG. 10, in the "execution stage information" of the signal operation status information, the bit value of D7 is an identifier of the type of terminal operation, where 0 means normal operation and 1 means terminal operation. The bit values ​​of D6 and D5 are identifiers of the current status, with 00 meaning standard status, 01 meaning first status, 10 meaning second status, and 11 meaning third status. The bit values ​​of D4 to D0 are identifiers of the floor number, with 00000 meaning floor 1, 00001 meaning floor 2, and 00010 meaning floor 3. In the same way, floors up to 24 can be defined.

[0099] [Examples of signal control plans] FIG. 11 is a table showing an example of a signal control plan created by the roadside repeater 70. As shown in FIG. In the example of FIG. 11, one cycle is made up of the following eight steps, and TS represents the cycle start time according to the local time of the device itself. The approach road R1 is an approach road that extends in a first direction (e.g., east-west) and is equipped with pedestrian lights. The approach road R2 is an approach road that extends in a second direction (e.g., north-south) that intersects with the first direction and is not equipped with pedestrian lights.

[0100] 1PG: Both vehicle and pedestrian lights on approach road R1 are green 1PF: Vehicle lights on approach road R1 are green and pedestrian lights are flashing green 1PR: The vehicle light on the approach road R1 is green and the pedestrian light is red 1Y: The vehicle light on the approach road R1 is yellow and the pedestrian light is red 1AR: Both inflow channel R1 and inflow channel 2 are red (all red) 2G: The vehicle lights on the approach road R2 are green. 2Y: The vehicle light on the approach road R2 is yellow. 2R: The vehicle lights on the approach road R2 are red

[0101] In the example of Figure 11, the durations of all eight stages except 1PG are fixed stages with a fixed time, but the duration of 1PG is not fixed in advance, unlike the other stages, and is defined as a time range. This means that 1PG is a variable stage that can be changed by centralized control, offset tracking operation, terminal sensitive control, etc.

[0102] [Signal information format] FIG. 12 is a diagram showing an example of a format of signal information for vehicles. Specifically, FIG. 12A is a diagram showing the data structure of the signal information, and FIG. 12B is an explanatory diagram showing the data values ​​and data contents stored in the header and data sections of the signal information. The traffic light information in FIG. 12B is traffic light information at the cycle start time TS of the incoming road R1 (traffic light information at the start of the green light on the incoming road R1) based on the traffic light control plan in FIG.

[0103] As shown in FIG. 12A, the signal information for vehicles has a data structure including a header section, a data section, and a footer section. The header section contains an identifier indicating the traffic light information, the size of the traffic light information, and the number of light colors to be provided (three in the example). The footer section stores a CRC value, etc. The data section stores the planned display time (in the example, the number of seconds) for the number of light colors (1) to (3) defined in the header section. Hereinafter, this planned display time will also be referred to as the "remaining seconds."

[0104] In FIG. 12B, the correspondence between the data values ​​(codes) of the light colors (1) to (3) and the actual signal light colors is as follows: Signal light color (1) with code "01" = Green light Signal light color (2) with code "02" = Yellow light Signal light color (3) with code "03" = red light

[0105] As shown in FIG. 12B, on the approach road R1, the shortest planned display time for light color (1) (=green light) is 40 seconds, and the longest planned display time is 70 seconds. The above minimum time (40 seconds) and maximum time (70 seconds) are calculated using the following formula based on the duration of 1PG, 1PF, and 1PR in the signal control plan. Shortest time (40 seconds) = Shortest time for 1PG (30 seconds) + 1PF (5 seconds) + 1PR (5 seconds) Shortest time (70 seconds) = Longest time of 1PG (50 seconds) + 1PF (5 seconds) + 1PR (5 seconds)

[0106] On the approaching road R1, the shortest and longest time for the number of seconds for which the light color (2) (= yellow light) is to be displayed is 5 seconds. On the approaching road R1, the shortest and longest time for the number of seconds for which the light color (3) (= red light) is to be displayed is 55 seconds. In this way, when the shortest and longest times match, it means that the number of seconds for which the light color is to be displayed is confirmed. The expected display time (remaining seconds) of the light color may be expressed in units of 100 ms or 10 ms, and the format itself is not limited to the format shown in FIG.

[0107] [Issues and solutions regarding signal information generation methods] Considering utilization in autonomous vehicles, it is desirable that the accuracy of the number of seconds of the signal information provided to vehicle 5 be limited to an error of ± several hundred milliseconds or less. Specifically, assuming that traffic light information will be utilized by autonomous vehicles, when providing the current light color status and the number of seconds the light color is expected to remain on, it is desirable that the error in the number of seconds remaining until the green light is green be within ± several hundred milliseconds in order to avoid sudden or unnecessary deceleration due to entering a dilemma zone.

[0108] However, even in the case of centralized control by the central device 6, the traffic signal controller 12 makes the final decision on the number of seconds for each variable step. Furthermore, the number of seconds for the variable steps in terminal sensitive operation, sensitive correction operation, offset following operation, etc. depends on the specifications of the traffic signal controller 12. For example, the standard specifications established by the National Police Agency only stipulate the functional requirements of the equipment, and the specific operation depends on product specifications that are not publicly disclosed. Therefore, it is difficult to predict the number of seconds required for the variable staircase operation to achieve the appropriate accuracy for a wide variety of traffic signal controllers 12.

[0109] The traffic signal controller 12 can also perform different operations depending on its internal settings (for example, the minimum guaranteed number of seconds for each floor, the target floor for which the offset following operation or the response correction operation is to be performed). Therefore, to emulate the operation of the traffic signal controller 12, the roadside repeater 70 must be configured with the exact same settings as the traffic signal controller 12. In this case, the complexity of operation and management and the possibility of human error in the configuration work become issues. In addition, since the definitions and contents of the configuration items are not subject to standard specifications, converting the settings to suit the traffic signal controller 12 also becomes an issue.

[0110] Therefore, it is possible to adopt a method (hereinafter referred to as the "post-correction method") that uses the signal information once generated and the monitoring results of the stage number based on the execution stage information, or the monitoring results of the current light color, to correct or estimate the remaining number of seconds for the green light to match the actual situation. However, in such post-correction methods, correction is performed after the detection of the predetermined event being monitored, and therefore there is a possibility that temporarily erroneous signal information is provided.

[0111] Specifically, errors caused by the time difference and remaining seconds estimation of the roadside repeater 70 are corrected by post-correction, causing the remaining seconds to suddenly increase or decrease. If the fluctuation range of this increase or decrease exceeds a predetermined error (for example, ±several hundred milliseconds), there is a concern that the decision to start deceleration to avoid a dilemma may be delayed, resulting in the need for sudden deceleration or unnecessary deceleration, which may affect the reliability and stability of automatic driving control. In particular, when correction is made based on the monitoring results of the signal lamp 11, the impact is significant because the correction is made after the signal lamp color changes.

[0112] The above problems are more specifically exemplified as follows. Example 1: When the execution time of the traffic signal information is shorter than the actual time The remaining seconds of the green signal in the traffic light information changes to the next yellow signal before the traffic light unit 11. Alternatively, the time period in which the remaining seconds of the green signal = 0 continues until the monitoring result of the traffic light color is obtained. Example 2: When the execution time of the traffic signal information is longer than the actual time The traffic light 11 first changes to the next yellow signal, and then the traffic light information changes to yellow later. Alternatively, the traffic light information suddenly changes to yellow when there are still seconds left of a green signal.

[0113] As such, one possible solution to the problem of the remaining number of seconds of signal information changing discontinuously is to provide a minimum remaining number of seconds (estimated value - downward estimated error) and a maximum remaining number of seconds (estimated value + upward estimated error) that take into account expected errors when terminal sensing operation, sensing correction operation, offset tracking operation, etc. are being performed. However, this still leaves the problem of not being able to determine the timing of the yellow light start with the desired error (plus or minus several hundred milliseconds).

[0114] In view of the above problems, in this embodiment, at the start of the green light, no correction or estimation of the number of seconds remaining for the green light is performed, and the maximum and minimum values ​​of the number of seconds remaining that are not corrections or estimates are applied without being determined, and the determined number of seconds remaining for the green light is provided a predetermined time before the start of the yellow light. In this way, even if the estimated error shown above is several seconds or more, it is possible to avoid sudden deceleration or unnecessary deceleration due to entering the dilemma zone.

[0115] Typically, the duration of a green signal (VG) for vehicles consists of multiple steps. For example, at an intersection with pedestrian lights, VG consists of pedestrian green (PG), pedestrian flashing green (PF), and pedestrian red (PR), and the duration of each step is defined. The execution time for VG varies dynamically depending on the traffic conditions, but as shown in Figure 11, the variable step with a variable execution time is designated as Pedestrian Green (PG), while the execution time for Pedestrian Flashing (PF) and Pedestrian Red (PR) is often operated as fixed steps with fixed execution times.

[0116] Therefore, the end of the variable stage is detected based on the stage number included in the execution stage information of the signal operation status information (Figure 10) or the judgment result of the light color monitoring unit 78, and at the time this end is detected, the number of seconds remaining for the green light until the start of the yellow light is updated to a fixed value and provided. This makes it possible to tolerate prediction errors of more than a few seconds, and enables the development of highly accurate prediction technology for execution times of less than a few hundred milliseconds, as well as the provision of highly accurate signal information suitable for autonomous driving while reducing costs such as complicated operational management.

[0117] [Contents of signal information generation process] 13 is a flowchart showing an example of the signal information generation process executed by the information processing unit 75. As shown in FIG. 13, the signal information generation process includes the following steps 1 to 3. Process 1: Creating a signal control plan (step ST1) Process 2: Determine the maximum / minimum values ​​of the variable step (Step ST2) Process 3: Creation of signal information at the time of TS (step ST3)

[0118] The information processing unit 75 executes the above processes 1 to 3 for each cycle to generate signal information for the next cycle and records it in the memory 77. When the cycle start time TS of the next cycle arrives, the information processing unit 75 outputs the signal information recorded in the memory 77 to the vehicle-side communication unit 73. Furthermore, when the local time of the device itself passes TS, the signal processing unit 75 sequentially updates the signal information by subtracting the remaining seconds from the currently displayed light color by the elapsed time, and outputs the updated signal information to the vehicle communication unit 73. Details of this output process will be described later.

[0119] Process 1) Creating a signal control plan (Step ST1) The information processing unit 75 creates a signal control plan to be applied to the next cycle from the signal control command (see FIG. 9) and signal operation status information (see FIG. 10) stored in the memory 77. The signal control plan includes a number of stages included in one cycle, the duration of each stage (for example, in seconds), and the cycle start time TS (see FIG. 11).

[0120] The information processing unit 75 determines the multiple levels to be included in the signal control plan and the duration of each level based on the offset value, level number, reference values ​​for splits 1 to 6, +variation value, -variation value, cycle length, constants representing the relationship between each level and each aspect, cycle start time, etc. included in the signal control command.

[0121] Process 2) Determine the maximum and minimum values ​​of the variable step (Step ST2) Next, the information processing unit 75 determines the maximum and minimum values ​​of the variable stage (1PG) in the signal control plan. For example, the information processing unit 75 determines whether or not the offset tracking operation is being performed based on the time difference between the offset value included in the signal control command and the cycle start time of the traffic signal controller. Also, based on the sensing permission of the signal control command, it determines whether or not the traffic signal controller 12A is performing terminal sensing control (control that changes the variable step based on the sensing information from the vehicle detector).

[0122] If the information processing unit 75 determines that offset tracking operation needs to be performed, it calculates the reference values ​​of splits 1 to 6 and the estimated offset tracking seconds to be allocated to each variable step. Furthermore, if terminal sensitive control is being performed, it calculates the estimated sensitive correction seconds to be allocated to each variable step based on the sensitive operation result of the previous cycle. Next, it corrects the reference value commanded by the signal control command using the offset tracking seconds and the sensitive correction seconds, and then sets the maximum number of seconds obtained by adding the maximum extension number of seconds by sensitive control specified in the sensitive permission and internal settings to the maximum value of the variable step (1PG), and sets the minimum number of seconds obtained by subtracting the maximum shortening number of seconds by sensitive control specified in the sensitive permission and internal settings to the minimum value of the variable step (1PG).

[0123] Here, when connecting to a traffic signal controller 12A from which detailed specifications and internal setting information cannot be obtained, or when the time between the traffic signal controller 12A and the roadside repeater 70 is not synchronized and the time difference between the offset value included in the signal control command and the cycle start time of the traffic signal controller 12A cannot be accurately obtained, if it is not possible to accurately estimate the number of seconds for offset tracking operation, number of seconds for sensitivity correction, etc. allocated to each variable step, the minimum value (estimated value - downward expected error) and maximum value (estimated value + upward expected error) are updated according to the expected error.

[0124] Process 3) Creation of signal information at the time of TS (step ST3) The information processing unit 75 generates traffic light information (e.g., FIG. 12) in a predetermined format at the time TS based on the calculated duration for each floor. For example, in the case of traffic light information for the approaching road R1, the planned display times for the green, yellow, and red lights are calculated using the following formulas. Expected number of seconds for green light to be displayed = 1PG + 1PF + 1PR Estimated number of seconds for yellow light to be displayed = 1Y Expected number of seconds for red light to be displayed = 1AR + 2G + 2Y + 2AR

[0125] Here, if the green light displayed at the variable step (1PG) and the subsequent fixed step (1PF+1PR) is defined as the "first light color," the yellow light displayed after the first light color is defined as the "second light color," and the red light displayed after the second light color is defined as the "third light color," then the signal information must include at least the first and second light colors, and may not include the third light color.

[0126] [Signal information output processing] FIG. 14 is an explanatory diagram showing an example of the signal information output process executed by the information processing unit 75. As shown in FIG. 14, table T1 is a signal control plan at time TS when 1PG is a variable-stage system. Data D1 represents signal information to be output at time TS, and data D2 represents signal information to be output when the end of the variable-stage system is detected.

[0127] When the local time (current time) of the device itself reaches the cycle start time TS, the information processing unit 75 outputs the signal information D1 at the time TS recorded in the memory 77 (step S11). Next, when the local time of the device passes TS, the information processing unit 75 sequentially updates the signal information D1 by subtracting the remaining seconds for the currently displayed light color by the elapsed time, and outputs the updated signal information to the vehicle communication unit 73.

[0128] That is, the information processing unit 75 updates the signal information D1 by counting down the remaining number of seconds for the currently displayed signal light color (1) (= green light) by the amount of time that has elapsed since TS (step S12), and outputs the updated signal information to the vehicle communication unit 73. In this case, as shown in Figure 14, for example, every time one second elapses from TS, the information processing unit 75 updates the shortest time for light color (1) to 39, 38, 37... 10 until it reaches the fixed step number of seconds following the variable step, and updates the longest time for light color (1) to 69, 68, 67...

[0129] Note that the countdown (step S12) updating of the remaining seconds and output of the traffic light information are not necessarily limited to one-second intervals. That is, the countdown (step S12) may be performed at an appropriate preset interval, such as every 100 milliseconds. This also applies to the countdown (step S14) of traffic light information D2, which will be described later.

[0130] As mentioned above, the information processing unit 75 of this embodiment can detect the end of the variable staircase by the staircase number of the execution staircase information included in the signal operation status information, or by the start of the green flashing of the pedestrian light. Therefore, when the information processing unit 75 detects the end of the variable stage, it replaces the output object with signal information D2 in which the remaining number of seconds of the fixed stage following the variable stage is set as a fixed value (step S13).

[0131] Specifically, the information processing unit 77 determines the maximum and minimum remaining seconds for signal light color (1) (=green light) to be the same value, and sets the determined signal information D2 as the output target. Next, when the local time of the device passes the end point of the variable staircase, the information processing unit 75 sequentially updates the signal information D2 by subtracting the remaining seconds for the currently displayed light color by the elapsed time, and outputs the updated signal information to the vehicle communication unit 73.

[0132] That is, the information processing unit 75 updates the signal information D2 by counting down the remaining number of seconds for the currently displayed signal light color (1) (= green light) by the amount of time that has elapsed since the end of the variable ladder (step S14), and outputs the updated signal information to the vehicle communication unit 73. In this case, for example, as shown in FIG. 14, the information processing unit 75 updates the minimum and maximum times of the light color (1) to 9, 8, 7 . . . every time one second has elapsed since the end of the variable staircase.

[0133] [Example of transition of remaining seconds for green light] In the output process of FIG. 14, when the variable staircase (1PG) ends in 30 seconds, the transition of the remaining seconds of the signal light color (1) (= green light) is as follows:

[0134] (Transition example 1: When 1PG ends in 30 seconds) (Min. 40: Max. 60)←TS (Min. 39: Max. 59) (Min 38: Max 58) ... (Min. 12: Max. 32) (Min. 11: Max. 31) (Minimum 10 = Maximum 10) ← Detects the end of the variable stage (30 seconds after TS) (Min 09 = Max 09) (Min 08 = Max 08) ...

[0135] In the output process of FIG. 14, the transition of the remaining seconds of the signal light color (1) (= green light) when the variable step (1PG) ends in 40 seconds can be summarized as follows:

[0136] (Transition example 2: When 1PG ends in 40 seconds) (Min. 40: Max. 60)←TS (Min. 39: Max. 59) (Min 38: Max 58) ... (Min. 11: Max. 31) (Min. 10: Max. 30) (Min. 10: Max. 29) ... (Min. 10: Max. 22) (Min. 10: Max. 21) (Minimum 10 = Maximum 10) ← Detects the end of the variable stage (40 seconds after TS) (min 9 = max 9) (min 8 = max 8) ...

[0137] In the output process of FIG. 14, when the variable staircase (1PG) ends in 50 seconds, the transition of the remaining seconds of the signal light color (1) (= green light) is as follows:

[0138] (Transition example 3: When 1PG ends in 50 seconds) (Min. 40: Max. 60)←TS (Min. 39: Max. 59) (Min 38: Max 58) ... (Min. 10: Max. 22) (Min. 10: Max. 21) (Min. 10: Max. 20) ... (Min. 10: Max. 12) (Min 10: Max 11) (Min 10 = Max 10) ← Detect end of variable stage (50 seconds after TS) (Min 09 = Max 09) (Min 08 = Max 08) ...

[0139] [First Modification: Modification of Signal Control Plan] In the above-described embodiment, as an example of a signal control plan, a case was given in which the duration of the green signal (VG) of a vehicle lamp is composed of pedestrian green (PG), pedestrian flashing green (PF), and pedestrian red (PR), but at least one fixed step (here, referred to as "XG") may be included before the pedestrian green (PG).

[0140] In this case, for example, the number of seconds for the green light (first light color) on approach road R1 is calculated using the formula 1XG+1PG+1PF+1PR. Therefore, the first light color is displayed based on the initial time (1XG+1PG) including the variable step and the fixed step after 1PG, 1PF+1PR. In this way, the first step constituting the green light (first light color) of the vehicle lamp does not necessarily have to be a variable step (1PG), but may be a fixed step (1XG).

[0141] [Second Modification: Modification of Roadside Repeater] In the roadside repeater 70 of Fig. 8, the transmission method of the traffic signal controller 12A may be the "M-type transmission method" or the "T-type transmission method." The traffic signal controller 12A of the M-type or T-type transmission method employs a step control type and does not support the table control method.

[0142] Therefore, the central device 6 transmits a proceed command to the traffic signal controller 12A, but does not transmit a signal control command to the traffic signal controller 12A. Therefore, the central device 6 may generate a downstream frame addressed to the roadside repeater 70, which includes a signal control command for remotely controlling the traffic signal controller 12A, and send the generated downstream frame to the communication line 8.

[0143] In the roadside repeater device 70 of Figure 8, the communication processing unit 74 may not be connected to the vehicle-side communication unit 73, and may be a processing unit that does not perform relaying involving protocol conversion, etc., for communication between the upper-side communication unit 71 and the vehicle-side communication unit 73. In this case, the roadside repeater 70 also has the vehicle-side communication unit 73 transmit the vehicle-directed signal information input from the information processing unit 75 to the communication device 30, so that at least the signal information output function is maintained.

[0144] [Third variant: Information provided by traffic signal controller] In the above embodiment, the case where the roadside repeater 70 executes the signal information generation process (FIG. 13) and output process (FIG. 14) has been exemplified, but these processes may also be executed by the new controller 12B. That is, the control unit 21 of the traffic signal controller 12A shown in Fig. 6B may execute the processes of Fig. 13 and Fig. 14 to provide the traffic signal information to the vehicle 5. Therefore, the information providing device that generates and outputs the traffic signal information may be the traffic signal controller 12A.

[0145] [Third Modification: Application to Step Control] In the step control, the central device 6 manages all signal control, and therefore the central device 6 also determines the number of seconds for the sensory correction operation and the offset following operation. Therefore, the control unit 61 of the central device 6 that performs the step control may execute the process of generating (FIG. 13) and the process of outputting (FIG. 14) the traffic light information. In other words, the central device 6 may be the information providing device that generates and outputs the traffic light information.

[0146] In step control, the traffic signal controller 12A does not transmit signal operation status information (FIG. 10), but transmits a "step response" including the number of the currently executed floor in response to a step command from the central device 6. Therefore, the central unit 6 can detect the end of the variable staircase by counting the number of seconds the variable staircase actually takes to run from the intervals between reception of the step responses.

[0147] [Other Modifications] The above-described embodiments (including modifications) are illustrative in all respects and are not restrictive. The scope of the present disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. For example, in the above-described embodiment, the variable level of the signal control plan is not limited to 1PG, but may be other levels. [Explanation of symbols]

[0148] 1 traffic light 2 Roadside sensors 3 Roadside communication equipment 4. In-vehicle communication device 5 vehicles 6 Central device (information providing device) 7 Router 8 Communication Line (1st Line) 8A Communication Line (1st Line) 8B Communication Line (Second Line) 8C communication line 9 Communication Line (Second Line) 10 Communication Line (3rd Line) 11 Signal lights 12 Traffic signal controller (information device) 12A old controller 12B New Control Unit 13 Control Line 14 Base station 21 Control section 22 Lighting unit drive unit 23 Communications Department 24 Memory section 30 Communication equipment 60 Central device (information providing device) 61 Control Unit 62 Display section 63 Communications Department 64 Memory section 65 Operation section 70 Roadside repeater (signal conversion adapter, information providing device) 71 Upper communication unit (first communication unit) 72 Traffic light communication unit (second communication unit) 73 Vehicle-side communication unit (third communication unit) 74 Communication processing unit 75 Information Processing Department 76 Synchronization processing section 77 Memory (storage section) 78 Light color monitoring section 79 Light color sensor

Claims

1. a storage unit that stores the following signal control plans; an information processing unit that generates signal information including the following first and second light colors and the remaining seconds therefor based on the stored signal control plan; a communication unit that transmits the generated signal information; An information providing device comprising: a light color monitoring unit that monitors the light color of a signal light device; The information processing unit Before the end of the variable stage of the signal control plan, the maximum and minimum values ​​of the remaining seconds of the first light color are applied to the signal information without being determined, An information providing device that, when the end of the variable ladder is detected based on the monitoring results of the light color monitoring unit, determines the maximum and minimum values ​​of the remaining seconds of the first light color as the same value. Signal control plan: Multiple levels, including variable levels, and data including duration of each level First light color: Signal light color of vehicle lighting equipment displayed during the initial time including variable stairs and fixed stairs after variable stairs Second light color: Signal light color of vehicle lighting equipment displayed after the first light color

2. the first light color is a green light, The information providing device according to claim 1 , wherein the second light color is a yellow light.

3. The information providing device 3. The information providing device according to claim 1, further comprising a roadside repeater for relaying communication between a traffic signal controller and a central device for centrally controlling said traffic signal controllers.

4. The information processing unit 4. The information providing device according to claim 3, wherein the end of the variable staircase is detected based on the staircase number included in the execution staircase information received from the traffic signal controller.

5. The information providing device 3. The information providing device according to claim 1, wherein the information providing device is a traffic signal controller that is centrally controlled by a central device.

6. The information providing device 3. The information providing device according to claim 1, which is a central device for centrally controlling traffic signal controllers.

7. a storage unit that stores the following signal control plans; an information processing unit that generates signal information including the following first and second light colors and the remaining seconds therefor based on the stored signal control plan; a communication unit that transmits the generated signal information; An information providing method executed by an information providing device including a light color monitoring unit that monitors the light color of a signal lamp, before the end of the variable stage of the signal control plan, applying the maximum and minimum values ​​of the remaining seconds of the first light color to the signal information without determining them; An information provision method including a step of determining the maximum and minimum values ​​of the remaining seconds of the first light color as the same value when the end of the variable ladder is detected based on the monitoring results of the light color monitoring unit. Signal control plan: Multiple levels, including variable levels, and data including duration of each level First light color: Signal light color of vehicle lighting equipment displayed during the initial time including variable stairs and fixed stairs after variable stairs Second light color: Signal light color of vehicle lighting equipment displayed after the first light color

8. a storage unit that stores the following signal control plans; an information processing unit that generates signal information including the following first and second light colors and the remaining seconds therefor based on the stored signal control plan; a communication unit that transmits the generated signal information; A computer program that causes a computer to function as an information providing device including a light color monitoring unit that monitors the light color of a signal lamp, before the end of the variable stage of the signal control plan, applying the maximum and minimum values ​​of the remaining seconds of the first light color to the signal information without determining them; A computer program including a step of determining the maximum and minimum values ​​of the remaining seconds of the first light color as the same value when the end of the variable staircase is detected based on the monitoring results of the light color monitoring unit. Signal control plan: Multiple levels, including variable levels, and data including duration of each level First light color: Signal light color of vehicle lighting equipment displayed during the initial time including variable stairs and fixed stairs after variable stairs Second light color: Signal light color of vehicle lighting equipment displayed after the first light color

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