JP4535191B2 - Road communication system and road communication device - Google Patents

Description

  The present invention relates to a system in which a road device and an in-vehicle device cooperate to support a driver's safe driving. The present invention relates to a traffic signal controller and a road communication device used in a communication system.

  Conventionally, for the purpose of preventing traffic accidents in and around the intersection, signal information such as the signal light color and duration of the traffic signal provided at the intersection has been provided to the vehicle, and the in-vehicle device has the signal information. Based on the above, a safe driving support system has been proposed that determines whether the vehicle should stop or can pass before the intersection, and performs vehicle speed control, or prompts the driver to decelerate or call attention ( For example, see Patent Document 1).

  In the device described in Patent Document 1, for example, time information until a signal lamp displaying a blue signal becomes a red signal is transmitted from a transmitting device provided on the road to the vehicle, and this time is measured on the in-vehicle device side. The vehicle is automatically braked when it is determined that there is no time to safely pass through the intersection, that is, when it is determined that the vehicle should stop before the intersection, based on the information and the traveling speed at that time. Control to decelerate and stop.

A road communication system for realizing such a safe driving support system usually includes a traffic signal controller that creates signal information related to a schedule of display time of a signal lamp, and the signal information received from the traffic signal controller. Although it is configured to include a road communication device provided to the vehicle side, road traffic is communicated from the traffic signal controller for the purpose of reducing the frequency of communication between the traffic signal controller and the road communication device. A method is proposed in which the road communication device updates the signal information and provides it to the vehicle in a second period (for example, 1 second) shorter than the first period (for example, 10 seconds) for transmitting the signal information to the device. (See, for example, Patent Document 2).
According to such a method, even when the frequency of communication between the traffic signal controller and the roadside communication device is reduced, the signal information is provided to the vehicle side as detailed information (information in units of one second). There is an advantage that it becomes possible.
Japanese Patent No. 2806801 JP 2008-152680 A

In the realization of the road communication system, when the traffic signal controller executes point sensitive control such as right turn sensitive control or dilemma sensitive control, the duration of the signal lamp color subject to the point sensitive control is uncertain. Therefore, there is a problem that it cannot be provided to the vehicle as confirmed information.
Therefore, there is a method of providing the duration as information in a range having a predetermined width. For example, when the duration of the green signal displayed by the point sensitive control is determined to be 30 seconds or more and 50 seconds or less, the minimum duration of the green signal is stored as 30 seconds and the maximum time is stored as 50 seconds in the signal information. The method can be adopted.
There is an advantage that it is useful information for the vehicle side as compared with the case of simply providing information that the duration is unknown.

By the way, in general traffic signal control, one cycle of a signal (period in which signal display makes a round) is divided into a plurality of floors, and a signal lamp color displayed on each floor and its duration are determined at the start of one cycle. Is used.
For example, at an intersection where two roads intersect, a state in which both a vehicle signal lamp and a pedestrian signal lamp on a certain road are green light is defined as “PG” as the first deck, The state in which the signal lamp remains a green signal and the pedestrian signal lamp is a blue blinking signal is defined as “PF” as the second floor, and the vehicle signal lamp on the road remains the green signal, and the pedestrian signal lamp A method is used in which the state where is a red light is defined as “PR” as “PR”. Then, how many seconds are allocated to each floor is determined according to traffic conditions and the like.

When performing point-sensitive control at this intersection, set in advance in the traffic signal controller which floor to execute (for example, bus-sensitive control on the first floor, dilemma-sensitive control on the third floor, etc.) When the set floor starts to be executed, a process of cutting off the floor at an appropriate timing is performed with reference to information such as a vehicle detector. The process of breaking the level is generally executed within a predetermined time range (the time range in which the point sensitive control is executed is referred to as “sensitive width”).
In this case, a floor that executes point sensitivity is referred to as a variable floor, and a floor that does not execute point sensitivity or the like and whose execution time is determined in advance is referred to as a fixed floor.
For example, if the execution time of the variable deck is determined to be in the range of 30 to 50 seconds (sensitivity range), after 30 seconds from the start of execution of the variable deck, whenever the conditions for censoring are met, This variable step can be cut off (for example, when 40 seconds have elapsed). And even if the conditions for termination are not met, this variable step is forcibly terminated when 50 seconds have passed.

For example, if you have a variable floor that performs right turn sensitive control (for example, a floor that displays a right turn blue arrow light), the right turn lane is monitored by the vehicle detector installed in the right turn lane, and the right turn vehicle train is interrupted. This variable step is censored at a time point that meets the condition that a few seconds have elapsed from the time point at which it was determined that it was (for example, 3 seconds later).
Then, if the right-turn vehicle train is not interrupted even after the upper limit of the sensitivity range has elapsed, even if there is still a right-turn vehicle, an operation is performed to cut off this variable deck at the upper limit. To do.

By the way, the signal light color to be provided in the signal information is composed of a plurality of floors (for example, when the blue light of the vehicle signal light device is composed of three floors of PG, PF, PR), When one of the floors is a variable floor, the duration of this signal lamp color is uncertain as a whole, and as described above, the duration of each signal lamp color stored in the signal information is It is preferable to provide it as information (for example, information that the green signal for vehicles is not shorter than 30 seconds and not longer than 50 seconds).
For example, when PG is a variable floor and the range is 20 to 40 seconds, and PF and PR are both fixed floors and 5 seconds, the signal information at the time of starting the execution of PG includes “vehicle signal lamp” It is desirable to store and provide the information that “the minimum duration of the green light is 30 seconds and the maximum time is 50 seconds”.

In this case, using the method disclosed in Patent Document 2, the traffic signal controller transmits signal information to the road communication device once every 10 seconds, and the signal information received by the road communication device is transmitted every second. If updated, the roadside communication device will update the information content one second after receiving the signal information, with the minimum duration of the green light of the vehicle signal lamp being 29 seconds and the maximum time being 49 seconds. Can be provided to the vehicle side.
That is, the shortest time and the longest time of the currently displayed signal lamp color among the information stored in the latest signal information received by the roadside communication device can be reduced with the passage of time starting from the reception time point ( The process of updating the content of the signal information on the road communication device side in this way is referred to as “countdown process”).
Before and after the time when the variable floor is cut off, the content of the signal information to be provided to the vehicle side changes discontinuously, so even if it is less than 10 seconds after the previous signal information is transmitted, It is preferable to transmit signal information with new contents. The signal information transmitted from the traffic signal controller to the roadside communication device at the time when the variable floor is cut off includes 10 seconds (PF and PF) as both the minimum time and the maximum time of the green light of the vehicle signal lamp. Information indicating that the PR is 5 seconds) is stored.

The present applicant has found that there are the following problems when executing such countdown processing.
In the above example, for example, the shortest time of the vehicle green signal included in the signal information received by the road communication device at the time when the sensitivity range of the variable floor PG is entered is 10 seconds, and the maximum time is 30 seconds (variable floor PG Since it is not known when it will be censored, its shortest time is 0 seconds and its longest time is 20 seconds, and the shortest and longest times of two fixed tiers (PF and PR) executed after PG are Therefore, the blue signal of the vehicle signal lamp composed of PG to PR is in the range of 10 to 30 seconds.) If this information is counted down as it is, the accuracy of the signal information is lowered.

For example, after 3 seconds from the time when this information is received, the content is usually updated to a content of 7 seconds and the longest time is 27 seconds by countdown processing. This is because the time for which the green signal for the vehicle is displayed is at least 10 seconds (the total time of the two steps of PF and PR before execution).
In other words, when counting down the duration of the signal lamp color including the variable floor, it is desirable to add a new device to the method of simply reducing the shortest time and the longest time as time passes. I found a problem.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a road communication system that can provide signal information with higher accuracy to a vehicle.

The road communication system according to the present invention includes a traffic signal controller that transmits signal information including information related to a display schedule of a signal lamp device to another device for each predetermined first period, the signal information received, And a roadside communication device having an updating means for updating the signal information every predetermined second period shorter than the first period from the time of reception, wherein the signal information is currently displayed The signal lamp color and the shortest time and the longest time of the duration are included, and the updating means performs a countdown process that is a process of reducing the shortest time and the longest time every second period, updating means, when from the traffic signal controller receives the instruction information to instruct the stop of the count down process, is configured to stop the countdown process of the shortest time, before When the currently displayed signal light color is composed of a plurality of floors, the traffic signal controller is a total value of the shortest times in the floors behind the currently executing execution floor among the plurality of floors. The instruction information is transmitted when a certain minimum guarantee time matches the shortest duration of the duration included in the signal information (claim 1).

As mentioned above, when providing the scheduled display time of the signal lamp color including the variable level of the point sensitive control, the accuracy of the shortest time may be reduced only by executing a simple countdown process. According to the present invention, more accurate signal information can be provided.

In this case, the instruction information may be included in the signal information as flag information, and the stop unit may stop the countdown process for the shortest time when the flag is on (ON) ( Claim 2).

The road communication system may further include an information relay device that relays information exchange between the two devices on a communication path between the traffic signal controller and the road communication device. Item 3).

Further, the road communication device itself used in this road communication system is very useful (claim 4).
As this road communication device, for example, an optical beacon can be used (claim 5).

As described above, according to the present invention, the longest time and the shortest time are counted down as they are even in the case of a road communication system in which the variable lamp is included in the signal lamp color to be provided in the signal information. Accordingly, it is possible to prevent the deterioration of the accuracy of the shortest time and to provide highly accurate signal information.

(First embodiment)
[Overall system configuration]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing an outline of a road communication system including a traffic signal controller according to the present invention.
The road communication system includes a traffic signal device 1 (comprising a traffic signal controller 1a and a plurality of signal lamps 1b, 1c, 1d, etc.), a road communication device 2 (comprising a communication antenna unit 2a, a communication control device 2b, etc.), an in-vehicle device. 3 and the central device 4 are included. The central device 4 is a device having a function of giving an instruction regarding control of the traffic signal 1, and a function of generating / transmitting traffic information to be provided to the vehicle, and is installed in the traffic control center. The central device 4 may be installed on the road instead of being installed in the traffic control center.
The central device 4 is connected to traffic signals installed at each of a plurality of intersections via communication lines such as telephone lines and communication devices such as routers. The traffic signal 1 is connected to a road device installed on each of a plurality of roads flowing into the intersection A between the road R1 and the road R2 via a communication line such as a telephone line.

The traffic signal 1 has a function of controlling a plurality of signal lamps. The right of traffic for a vehicle traveling on the road R1 is given by the vehicle signal lamp 1b, and the right of traffic for the vehicle running on the road R2 is given by the vehicle signal lamp 1d. To display each. In this example, the pedestrian crossing H is provided only on the road R2, and the pedestrian signal lamp 1c displays the right of passage for pedestrians using the pedestrian crossing H.
The traffic signal controller 1a has a function of receiving from the central device 4 traffic information including traffic regulation information and a signal control command that is an instruction regarding control of the signal lamp, and each signal lamp such as the signal lamp 1b according to the instruction. Controls lighting, extinguishing and blinking of the instrument. Further, the traffic signal controller 1a creates signal information including a signal lamp color to be displayed and its duration by a process described later, and a plurality of road signals connected to the traffic signal controller 1a together with the received traffic information. It can be transmitted to the communication device 2.

  FIG. 2 is a block diagram showing the configuration of the traffic signal controller 1a. The control unit 101 is composed of one or a plurality of microcomputers. The control unit 101 is connected to the lamp driving unit 102, the communication unit 103, and the storage unit 104 via an internal bus, and the control unit 101 controls operations of these hardware units. In addition, the control unit 101 creates signal information by a signal information creation process described later.

The lamp drive unit 102 includes a semiconductor relay (not shown), and corresponds to each of the blue, yellow, and red lamps of the plurality of signal lamps 1b based on the signal lamp output command input from the control unit 101. The AC voltage (AC100V) or DC voltage supplied to each color signal lamp is turned on / off.
The communication unit 103 includes a central communication unit 1031 for performing communication with the central device 4, and can receive traffic information, signal control commands, and the like from the central device 4. In addition, the communication unit 103 includes a terminal communication unit 1032 that transmits traffic information received at a predetermined cycle (for example, 100 msec) and generated signal information to the roadside communication device 2.
The storage unit 104 stores received traffic information and signal control commands, generated signal information, information on various constants such as constants indicating the relationship between each floor and each display, and the like.

The road communication device 2 is a wireless communication device that can communicate with a communication method such as an optical beacon, a radio wave beacon, DSRC (Dedicated Short Range Communication) or WiMAX (Worldwide interoperability for microwave access). A function of wirelessly communicating various types of information with the in-vehicle device 3 mounted on the vehicle. The roadside communication device 2 includes a communication antenna unit 2a for communicating various information with the in-vehicle device 3, and a communication control device 2b for controlling the communication antenna unit 2a.
FIG. 3 is a block diagram showing the configuration of the communication control device 2b of the roadside communication device 2. The control unit 201 is composed of one or a plurality of microcomputers. A signal communication unit 203 and the like are connected to the control unit 201 via an internal bus, and the control unit 201 controls operations of these hardware units.
In the storage unit 202 of the road communication device 2 installed on the road R1, road shape information regarding the distance and gradient from the road communication device 2 to the intersection A, information on the area including the intersection A, and the like are stored in advance. . Note that these pieces of information are not limited to a configuration stored in advance, and may be a configuration acquired and stored from the central device 4 or the like. The signal communication unit 203 has a function of receiving traffic information and signal information from the traffic signal device 1, and the road-to-vehicle communication unit 204 transmits the information to the in-vehicle device 3 via the communication antenna unit 2a.

  The central device 4 transmits traffic information and signal control commands to a plurality of traffic signals at a predetermined cycle. FIG. 4 is a diagram showing a format of the signal control command. In FIG. 4, split 1 indicates the split of current display 1, and split 6 indicates the split of current display 6. The details of this format are described in a standard document issued by the New Traffic Management System Association (hereinafter referred to as UTMS Association).

  The vehicle 10 is equipped with an in-vehicle device 3 and wirelessly communicates various information with the on-road communication device 2. When the vehicle 10 equipped with the in-vehicle device 3 passes through the communication area Q (the hatched portion in FIG. 1) of the road communication device 2, the vehicle 10 performs wireless communication with the road communication device 2, and traffic information, signal information, Get road shape information.

[Outline of operation of vehicle 10]
When the vehicle 10 acquires traffic information, signal information, and road shape information by the in-vehicle device 3, the vehicle 10 performs the following safe driving support control process based on these. That is, the vehicle 10 determines whether or not the intersection A can be safely passed in blue. If it is determined that the vehicle 10 can pass, the vehicle 10 travels while maintaining the current speed, and if it is determined that the vehicle cannot pass, Decelerate so that you can stop safely at the stop line before intersection A. At that time, if the traffic information includes traffic regulation information related to the road R1, the speed control is performed in consideration of the traffic regulation. For example, if there is a speed limit of 40 km / h on the road R1, the vehicle 10 performs speed control so as not to exceed 40 km / h.

  The in-vehicle device 3 mounted on the vehicle 10 has a configuration as shown in FIG. The GPS processing unit 301 receives GPS signals from GPS satellites, and measures the position (latitude, longitude, and altitude) of the vehicle 10 based on time information, GPS satellite orbits, and positioning correction information included in the GPS signals. . The azimuth sensor 302 is composed of an optical fiber gyro and the like, and measures the azimuth and angular velocity. The vehicle speed acquisition unit 303 acquires the speed data of the vehicle 10 measured by the vehicle speed sensor 1001 detecting the angular speed of the wheels.

  The communication unit 304 receives traffic information, signal information, and distance information from the road device 2. This signal information includes information related to the schedule of the display time of the signal lamp in the traveling direction. The communication unit 304 outputs the received traffic information, distance information, result information calculated by the processing unit 308 based on the signal information, and the like to the travel control unit 1005.

  The storage unit 305 stores road map data, various information received by the communication unit 304, result information calculated by the processing unit 308, and the like. The display unit 306 displays on the monitor 1002 image data drawn by superimposing the guidance route to the destination searched by the processing unit 308 on the road map data. The voice output unit 307 outputs voice data for route guidance along the guidance route created by the processing unit 308 from the speaker 1003.

  The processing unit 308 is configured by one or a plurality of microcomputers, and is based on the data measured by the GPS processing unit 301, the azimuth and angular velocity measured by the azimuth sensor 302, and the speed acquired by the vehicle speed acquisition unit 303. Map matching processing is performed to determine the position of the vehicle on the road map data stored in the storage unit 305. In addition, the processing unit 308 searches for a guidance route from the position of the vehicle on the road map data to the destination, and creates route guidance voice data along the guidance route. In addition, the processing unit 308 performs an operation for converting the signal information received by the communication unit 304 and the information about the route to the stop line into a format that can be easily processed by the travel control unit 1005 described later, and thus provides basic information for travel control. Information is calculated.

  The travel control unit 1005 includes one or more microcomputers, and includes traffic information acquired from the communication unit 304, distance information, calculation result information of the processing unit 308, and speed data of the vehicle 10 acquired from the vehicle speed sensor 1001. Based on this, a safe driving support control process is performed. That is, it is determined whether or not the intersection A can be safely passed in blue. If it is determined that the intersection A can be passed, the drive unit (engine) 1006 is controlled to maintain the current speed. If it is determined that the vehicle cannot pass, the braking unit (brake) 1007 is controlled, the speed is reduced so that the vehicle can be safely stopped at the stop line P before the intersection A, and the vehicle is stopped at the stop line P. If the traffic information includes traffic regulation information related to the road R, the driving unit 1006 and the braking unit 1007 are controlled in consideration of the traffic regulation.

[Signal information creation procedure]
Next, the procedure of signal information creation processing of the traffic signal controller 1a will be described. The traffic signal controller 1a has a reference value of the splits 1 to 6 included in the signal control command stored in the storage unit 104, a + variable value and a -variable value, a cycle length, each level, before the start of one cycle A one-cycle signal control plan is created based on a constant representing the relationship between the current and each indication, and the lighting time of each signal lamp color on each road flowing into the intersection A is calculated based on this signal control plan.

FIG. 5 is a diagram showing an example of a signal control plan calculated for one cycle with the traffic signal controller 1a. One cycle of the traffic signal controller 1a is composed of eight steps as shown in FIG.
1PG indicates that both the vehicle signal lamp 1b and the pedestrian signal lamp 1c on the road R1 side are in a green signal state. It indicates the state of the signal, and 1PR indicates a state in which the vehicle signal lamp 1b on the road R1 side is a green signal and the pedestrian signal lamp 1c is a red signal.

  Here, of these eight stairs, the durations of 1PG and 1PR are not determined in advance, and are calculated as having a certain range, unlike the other tiers. However, these tiers are variable. Indicates that it is a floor. Therefore, 1PG and 1PR are cut off somewhere in this range based on information from a vehicle detector (not shown) or the like.

FIG. 6 shows an example of signal information created and output immediately after starting one-cycle signal control based on this signal control plan. As shown in FIG. 6A, the signal information includes a header part, a data part, and a footer part. (B) is an example showing details of information contents.
The header portion stores the size of the signal information and the number of lamp colors (3) to be provided to the vehicle by the traffic signal controller 1a, and each lamp color is scheduled to be displayed in the subsequent area. Numbers are stored for the number of lamp colors. Although not shown, a CRC, SUM value, etc. are stored in the footer section.

The data portion stores the number of seconds for which lamp colors are scheduled to be displayed corresponding to the number of lamp colors stored in the header portion. In this example, information indicating that the signal lamp color of the vehicle signal lamp currently displayed on the road R1 is a green signal (code “01”) is stored. 40 seconds (“28” in hexadecimal) and 70 seconds (“46” in hexadecimal) are stored as the longest time.
The meaning of the minimum guaranteed time stored next will be described later, but this minimum guaranteed time is the same as the signal lamp for vehicles on the floor after the currently executed floor (1PG). Stores the total value of the shortest time of (vehicle green light).
Here, 10 seconds (hexadecimal “0A”) is stored as the total value of the shortest times of 1PF and 1PR that meet this condition.

  The vehicle yellow signal (code “02”) is displayed next to the vehicle green signal, and the shortest time and the longest time of the scheduled display seconds are both 5 seconds (“05” in hexadecimal). In this way, the scheduled number of seconds for displaying the signal lamp color in which the shortest time and the longest time coincide is determined. Further, the vehicle red signal (code “03”) is displayed next to the vehicle yellow signal, and the scheduled display time is 55 seconds (hexadecimal “37”). The scheduled display seconds may be expressed in units of 100 ms or 10 ms, and the format itself is not limited to such a format.

  In this embodiment, in order to reduce the communication frequency between the traffic signal controller 1a and the communication control device 2b, signal information is transmitted to the communication control device 2b at a frequency of about once every 10 seconds. However, the signal information is transmitted immediately at the time when the execution of the floor progresses or when the scheduled display time of the signal information changes discontinuously.

[Countdown process and its stop process]
The communication control device 2b that has received the signal information executes a countdown process at a rate of once per second.
For example, the communication control device 2b that has received the signal information of FIG. 6B performs a countdown process, and after 3 seconds, for example, the display schedule of the light color (1) as shown in FIG. 6C. The shortest time in seconds is updated to 37 seconds (hexadecimal “25”), and the longest scheduled second is updated to 67 seconds (hexadecimal “43”).
Then, when signal information is newly received from the traffic signal controller 1a during the countdown process, the signal information held by itself is overwritten on the latest signal information, and the latest signal information is counted down.

  Here, it is assumed that the vehicular signal lamp 1b continues to display the green signal as it is, and signal information as shown in FIG. 7A is sent to the communication control device 2b at a timing immediately before entering the sensitive range. The execution state of the control by the traffic signal controller 1a at this time has passed 27 seconds since the start of 1PG, and the duration time of 1PG is 3 seconds for the shortest time and 23 seconds for the longest time. . Therefore, the duration of the green signal for vehicles is 13 seconds ("0D" in hexadecimal) and 43 seconds ("2B" in hexadecimal) as the shortest time.

From the time when this signal information is received, the communication control apparatus 2b executes a countdown process every second. After 3 seconds, the shortest time is 10 seconds and the longest time is 40 seconds.
Here, since the minimum guaranteed time of the lamp color (1) stored in the signal information is 10 seconds and coincides with the shortest time of the lamp color (1), the communication control device 2b at this point in time is the shortest time. Stop the countdown process for.
FIG. 7B shows a state after another 5 seconds have elapsed after the countdown process relating to the shortest time is stopped. Since the countdown process is stopped, the shortest time of the light color (1) remains 10 seconds ("0A" in hexadecimal), and only the longest time is reduced by 5 seconds to 38 seconds ("26" in hexadecimal). It has become.

Here, the significance of the traffic signal controller 1a including the minimum guaranteed time in the signal information and stopping the countdown process of the communication control device 2b is as follows.
Since there are two floors, 1PF and 1PR, which are the floors for displaying the green light for vehicles, behind the currently executed floor 1PG, as long as 1PG continues within the sensitivity range of 1PG, these two The situation that “the green signal for the vehicle is displayed for at least 10 seconds (the green signal for the vehicle for 10 seconds is guaranteed)” continues by the floor.

However, since the road communication device 2 that receives the signal information cannot grasp the details of such signal control, if there is no instruction from the traffic signal controller 1a side, the countdown process proceeds as it is, The minimum time of (1) is set to less than 10 seconds, and the accuracy of the signal information provided to the vehicle side is lowered.
Therefore, by storing the minimum guaranteed time and informing the roadside communication device 2 in this way, the countdown process does not fall below the guaranteed green signal time (the countdown process of the shortest time of the vehicle green signal) Is stopped with a minimum guarantee time), and the accuracy of the signal information can be improved.

At this point, since the traffic signal controller 1a is executing within the range of the sensitivity range of 1PG, 1PG can be terminated at any time. Therefore, if the traffic signal controller 1a cuts off 1PG and the floor has advanced to 1PF, the traffic signal controller 1a transmits the latest signal information to the communication control device 2b when the floor has advanced. The signal information to be transmitted has the contents as shown in FIG.
Even if the floor advances to 1 PF, the signal lamp for the vehicle remains a green signal, so the information on the signal lamp color itself does not change. The shortest time of the green light for a vehicle is 10 seconds (“0A” in hexadecimal) which is the total value of the shortest times of 1PF and 1PR, and the longest time is the total value of the longest times of 1PF and 1PR. Second (hexadecimal number “14”).
The minimum guaranteed time sent at this time is 5 seconds (hexadecimal number “05”), which is the shortest time of 1PR after 1PF, which is the currently executing ladder.

And the communication control apparatus 2b which received this signal information performs a countdown process every second from the time.
In this case, the countdown process of the shortest time that has been stopped can be restarted. This is because the minimum time (10 seconds) of the lamp color (1) stored in the received signal information is longer than the minimum guaranteed time (5 seconds) of the lamp color (1).

Thereafter, the communication control device 2b counts down both the shortest time and the longest time of the lamp color (1), and when the shortest time becomes 5 seconds and the longest time becomes 15 seconds, the traffic signal controller 1a. 8 is transmitted from the traffic signal controller 1a to the communication control device 2b again at this time.
In this signal information, the minimum guaranteed time is 0 seconds. This is because there is no floor behind the 1PR in which the vehicular signal lamp has the same green light as 1PR.
And the communication control apparatus 2b which received this signal information counts down both the shortest time and the longest time of lamp color (1), and when the shortest time becomes 0 second and the longest time becomes 10 seconds, Again, the countdown process for the shortest time of the lamp color (1) is stopped. This is because the shortest time is 0 seconds which is the same as the minimum guaranteed time. At this point, the traffic signal controller 1a enters the 1PR sensitivity range, so that it is possible to end this 1PR at any time for 10 seconds and proceed to the next floor 1Y.

Here, as an example for stopping the countdown processing, a method of transmitting the minimum guaranteed time of the currently displayed signal lamp color from the traffic signal controller 1a to the communication control device 2b is shown. You may make it transmit the instruction | indication which stops a countdown process from the traffic signal controller 1a with respect to the communication control apparatus 2b at the timing judged that the time should not be counted down any more.
The instruction may be given by, for example, a method in which a new area is provided in the signal information, flag information is stored therein, and the countdown process is urged to stop when the flag is turned on. It is also possible to use a method of creating and transmitting different data.

Although the method of stopping only the shortest time countdown process is shown here, only the longest time countdown process may be stopped or both countdown processes may be stopped depending on the application.
For example, when the signal information provided from the road communication system to the in-vehicle device 3 does not have to be very accurate, and it is sufficient if only an approximate time is known, it is not necessary to perform an update process in the road communication device 2. . For example, if the road is congested, the start and stop are repeated, and the traffic situation is such that it will take a long time to reach the stop line after receiving the road communication device 2, it will take a special cycle. There is no need to update. In such a case, instead of stopping the update process, the control unit 201 of the roadside communication device 2 can be used for another process.

  In addition, when it is considered that some abnormality has occurred in the update process due to a failure of the control unit 201 of the roadside communication device 2, the received signal information is directly transmitted to the in-vehicle device 3 without performing the update process. In some cases, it is desirable to stop the countdown process.

(Second Embodiment)
In the first embodiment, the method of improving the accuracy of signal information by stopping the countdown has been described. However, in the second embodiment, the same signal lamp color (for example, a vehicle blue signal for the road R1) is stepped. A method for storing the scheduled display time in the signal information by dividing the field for each floor will be described.

FIG. 9 is a diagram showing an example of signal information when the second embodiment is adopted.
(A) and (b) both show the contents of signal information sent immediately after the signal control plan of FIG. 5 is determined.
In FIG. 9A, the shortest time and the longest time are stored for each floor for the signal lamp color currently being displayed. As shown in the figure, the signal light colors of the light colors (1) to (3) are all blue signals (code “01”) and correspond to the floors 1PG to 1PR, respectively. That is, the light color (1) indicates 1PG, and the shortest time is 30 seconds ("1E" in hexadecimal) and the longest time is 50 seconds ("32" in hexadecimal). Similarly, the light color (2) indicates 1PF, and the shortest time and the longest time are both 5 seconds ("05" in hexadecimal), and the light color (3) indicates 1PR and the shortest time is 5 seconds ( Hexadecimal "05") and the longest time is 15 seconds (hexadecimal "0F").

In the road communication device 2 that has received such signal information, the countdown process is executed as in the first embodiment, and the shortest time and the longest time of the lamp color (1) are reduced. Then, when the shortest time is 0 seconds and the longest time is 20 seconds, the longest time is kept at 0 seconds, unless the traffic signal controller 1a notifies that the floor has advanced. Count down only the time.
By doing in this way, the same signal lamp color (vehicle blue signal) has accurate information that the remaining time exists for the amount stored in the two subsequent fields of lamp color (2) and lamp color (3). It is possible to notify the in-vehicle device 3 side.

Note that, as shown in FIG. 9B, 1PG, which is currently being executed, is assigned to the light color (1), and the remaining two steps of 1PF and 1PR are combined into one and expressed as light color (2). You may make it do. In this case, the shortest time is 10 seconds ("0A" in hexadecimal) and the longest time is 20 seconds ("14" in hexadecimal).
In addition, although not shown, the signal lamp color (for example, the vehicle red signal) displayed after the currently displayed green signal for the vehicle is also divided into information for a plurality of floors at this time and transmitted. Also good.

According to the second embodiment, as the number of floors increases, the size of the signal information increases accordingly, and thus the amount of communication data increases. Therefore, the second embodiment is configured with a plurality of floors. Even if it is a signal lamp color, if all are fixed floors, it is desirable to transmit without dividing.
For example, if 1PG to 1PR are all fixed floors, it may not be divided and transmitted as information for each floor. Also, if only 1PG is a variable floor and 1PF and 1PR are fixed floors, only the shortest time and longest time of 1PG are stored independently in separate fields, and the rest are integrated as shown in FIG. 9B. Is more desirable.

  In the above two embodiments, for example, the communication between the traffic signal controller 1a and the on-road communication device 2 may be wireless communication or wired communication. The structure provided between these may be sufficient.

  In the above-described embodiment, the traffic signal controller 1a and the road communication device 2 are configured to be housed in separate housings, but the present invention is not limited to this, and the traffic signal controller 1a and the road communication device 2 A configuration in which the communication device 2 is housed in one housing may be employed. In this case, information exchange between the traffic signal controller 1a and the on-road communication device 2 may be performed using any of wired, wireless, internal buses, and the like.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a schematic diagram showing an outline of a road communication system according to the present invention. It is a block diagram which shows an example of a structure of the traffic signal controller 1a. It is a block diagram which shows an example of a structure of the communication control apparatus 2b of the roadside communication apparatus 2. FIG. It is a figure which shows the format of a signal control command. It is a figure which shows an example of a signal control plan. (A) is a figure which shows an example of the outline | summary of the format of signal information, (b) And (c) is a figure which shows an example of the detail of data content. (A) And (b) is a figure which shows an example of the detail of the data content of signal information. (A) And (b) is a figure which shows an example of the detail of the data content of signal information. (A) And (b) is a figure which shows an example of the detail of the data content of signal information. It is a block diagram which shows the structure of the vehicle-mounted apparatus and other apparatus which are mounted in the vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traffic signal 1a Traffic signal controller 1b, 1c, 1d Signal lamp 101 Control part 102 Lamp drive part 103 Communication part 1031 Central communication part 1032 Terminal communication part 104 Storage part 2 Roadside device 2a Communication antenna part 2b Communication control apparatus 201 Control Unit 202 Storage unit 203 Signal communication unit 204 Road-to-vehicle communication unit 3 In-vehicle device 301 GPS processing unit 302 Direction sensor 303 Vehicle speed acquisition unit 304 Communication unit 305 Storage unit 306 Display unit 307 Audio output unit 308 Processing unit 4 Central device 5 Router 10 Vehicle 1001 Vehicle speed sensor 1002 Monitor 1003 Speaker 1005 Travel control unit 1006 Drive unit 1007 Braking unit A Intersection Q Communication area R1, R2 Road

Claims (5)

A traffic signal controller for transmitting signal information including information related to a display schedule of a signal lamp to another device every predetermined first period;
A road communication system including an on-road communication device that receives the signal information and has an update unit that updates the signal information every predetermined second period shorter than the first period from the reception time;
The signal information includes the currently displayed signal lamp color, the shortest time and the longest time of the duration,
The update means performs a countdown process that is a process of reducing the shortest time and the longest time every second period,
The update means is configured to stop the countdown process of the shortest time when receiving instruction information for instructing to stop the countdown process from the traffic signal controller ,
The traffic signal controller is
When the currently displayed signal lamp color is constituted by a plurality of floors,
The indication information when the minimum guaranteed time, which is the total value of the shortest times in the tiers behind the currently executed execution tier among the plurality of tiers, matches the shortest duration of the duration included in the signal information. road communication system according to claim <br/> to send. The instruction information is flag information included in the signal information,
The road communication system according to claim 1, wherein the stop means stops the countdown process for the shortest time when the flag is on.   The road communication system further includes an information relay device that relays information exchange between the two devices on a communication path between the traffic signal controller and the road communication device. A road communication system according to claim 1. The road communication apparatus used for the road communication system as described in any one of Claims 1 thru | or 3 .   The road communication device according to claim 4, wherein the road communication device is an optical beacon.

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