JP5403439B2 - Road communication system and traffic signal controller - Google Patents

Description

  The present invention relates to a system that supports a driver's safe driving in cooperation with a road device and an in-vehicle device, and in particular, a road communication system that provides signal information such as a signal lamp color and its duration essential to the system, and the road The present invention relates to a traffic signal controller used in a communication system.

  Conventionally, in order to prevent a traffic accident caused by a vehicle in and near an intersection, signal information such as a signal light color and duration of a traffic signal provided at the intersection is provided to the vehicle, and the vehicle-mounted device mounted on the vehicle. Advocated a safe driving support system that determines whether to stop or pass before the intersection based on the signal information, and controls the speed of the vehicle or prompts the driver to decelerate or alert (For example, refer to Patent Document 1).

  In the apparatus described in Patent Document 1, for example, time information until a traffic signal displaying blue turns red is transmitted from a transmission device provided on the road to the vehicle, and this time information is transmitted on the in-vehicle device side. And the travel speed at that time, and if it is determined that there is no time to safely pass the intersection, that is, if it is determined that the vehicle should stop before the intersection, the vehicle is automatically braked and The vehicle is controlled to decelerate and stop before stopping at the intersection.

Japanese Patent No. 2806801

  In a safe driving support system, the accuracy of the signal lamp color and its duration in the signal information is extremely important. However, since it usually takes a predetermined time from when the signal information is created by the traffic signal to reach the in-vehicle device, the signal lamp color and its duration are accurate when the traffic signal creates the signal information. However, when the signal information arrives at the in-vehicle device, there is a problem that the actual duration is shorter than the duration in the signal information by the required time.

  And if the accuracy of a signal lamp color and its continuation time is impaired for the said required time, a safe driving assistance system may not be able to perform appropriate control. This will be described with a specific example. For example, when the green signal currently displayed is 10 seconds remaining, the traffic signal creates and transmits signal information of the signal lamp color “blue” and the duration “10 seconds”, and reaches 1 on-board device. If it takes 2 seconds (that is, the required time is 1 second), the in-vehicle device uses the received signal information to set the duration to 10 seconds even though the duration of the green signal at the time of arrival is actually 9 seconds. It will be judged. However, a vehicle that travels at a speed of 90 km / h, for example, travels as much as 25 m during this one-second gap. In that case, the signal light color actually switches from blue to yellow after 9 seconds, and the position of the vehicle at that time is in front of the stop line, so the vehicle should be controlled to stop by operating the brake. In addition, it may be mistakenly recognized that the vehicle will be switched after one second, and the vehicle position at that time may be determined to be after passing the stop line further 25 m, and the vehicle may be controlled to maintain the speed. .

  Accordingly, an object of the present invention is to provide a road communication system that can provide accurate signal information to an in-vehicle device.

A road communication system according to an embodiment of the present application includes a traffic signal controller having signal information creating means for creating signal information including information related to a schedule for switching a signal lamp, and a road-to-vehicle space that transmits the signal information to an in-vehicle device. A road communication device having a communication means, wherein the traffic signal controller and the road communication device are configured to communicate with each other, wherein the signal information creation means creates the signal information. in, Ru using the communication time required for the said road communication device from the traffic signal controller.

  According to the present invention, the traffic signal controller is displayed at the time when the road communication device is scheduled to transmit signal information to the in-vehicle device in consideration of the communication required time from the traffic signal controller to the road communication device. If the in-vehicle device receives this signal information in order to create signal information including the transmission signal lamp color and the scheduled duration of the transmission signal lamp color, the signal lamp color actually displayed at the time of reception and the continuation thereof The scheduled time matches the content of the signal information. Therefore, accurate signal information can be provided to the in-vehicle device.

  Note that the communication line used for communication may be wired or wireless. The communication here includes not only the exchange of information through a communication line but also the exchange of information through an internal bus, a shared memory, or the like.

The signal information includes a transmission signal lamp color displayed at a time when the road-to-vehicle communication unit plans to transmit the signal information, and a scheduled duration time of the transmission signal lamp color. Determines the signal lamp color at transmission and the scheduled duration based on the duration of the signal lamp color at the time of creation displayed at the time of creation of the signal information and the required communication time. even if the good.

  By doing so, the traffic signal controller can transmit the duration of the signal light color at the time of creation displayed at the time of creating the signal information and the time required for communication from the traffic signal controller to the roadside communication device. Therefore, if the in-vehicle device receives this signal information, the signal light that is actually displayed at the time of receiving the signal information is generated. The color and its scheduled duration coincide with the content of the signal information. Therefore, accurate signal information can be provided to the in-vehicle device.

The traffic signal controller further includes communication time calculation means for calculating the communication required time, and the communication time calculation means is configured to calculate the communication required time from the traffic signal controller to the road communication device. The communication speed in one or a plurality of communication sections to reach, the information relay processing time in one or a plurality of transit devices from the traffic signal controller to the road communication device, and the magnitude of the signal information using even good.

  The required communication time varies depending on the number of devices passing through the communication path, the processing time of the devices, the communication speed in the communication section, and the like. If it does as mentioned above, since communication required time can be calculated in consideration of these, accurate signal information can be provided by an in-vehicle device.

The traffic signal controller further includes dummy information transmitting means for creating dummy information having a predetermined size and transmitting the dummy information to a road communication device, and communication time measuring means for measuring the required communication time. The road communication device further includes dummy information return means for receiving the dummy information, creating dummy response information for the dummy information, and returning the dummy response information to the traffic signal controller, and the communication time measuring means includes: in the measurement of the time required for communications, wherein after transmitting the dummy information, but it may also be used period until receiving the dummy response information.

  In this way, since the required communication time can be directly measured, the accuracy of the signal information provided to the in-vehicle device can be further improved.

The signal information creation means determines the transmission time signal lamp color as the creation time signal lamp color when the required communication time does not exceed the duration time, and determines the scheduled duration from the duration time to the communication time. It is determined to be a value obtained by subtracting the required time not good. Further, when the required communication time exceeds the duration, the signal lamp color at the time of transmission is determined to be a future signal lamp color displayed in the future rather than the signal lamp color at the time of creation, and in the determination of the scheduled duration time, You may use duration, the said communication required time, and the display time of the said future signal lamp color .

  In this way, it is possible to create signal information in consideration of the magnitude relationship between the duration from the time of creation of the signal light color at the time of creation and the required communication time, and thus providing accurate signal information to the in-vehicle device Can do.

Further, the traffic signal controller is configured to transmit the signal information to the road communication device every predetermined first period, and when the road communication device receives the signal information, the reception time point from each time the predetermined second period has elapsed shorter than the first period, yet good further include updating means for updating the signal information.

  By doing so, even when the traffic signal controller transmits signal information every larger first period (for example, 100 msec), the second period (for example, 10 msec) shorter than the first period has elapsed for the road device. Since the signal information is updated each time, more accurate signal information can be provided to the in-vehicle device in units of 10 msec.

Moreover, traffic signal control apparatus according to the present embodiment, Ru traffic signal controller der in road communication system described above.

Further, the road communication system according to the embodiment of the present application transmits a traffic signal controller having signal information generating means for generating signal information including information related to a schedule for switching a signal lamp, and the signal information to an in-vehicle device. A road communication device having a road-to-vehicle communication means, and configured to communicate between the traffic signal controller and the road communication device, wherein the signal information is the signal information creating means. The signal light color at the time of creation displayed at the time when the signal information is created, the duration of the signal light color at the time of creation from the creation time, the time required for communication from the traffic signal controller to the roadside communication device, the including.

In addition, the in-vehicle device according to the embodiment of the present application is based on the signal information generated at the traffic signal controller, including means for receiving from the road communication device signal information including information related to the schedule for switching the signal lamp. An in-vehicle device having a displayed signal lamp color and a means for calculating a scheduled duration of the signal lamp color, wherein the signal information includes a signal lamp color at the time of creation displayed at the time when the signal information is created , the creation and duration from the time of preparation of the traffic light color, the traffic signal controller from the communication duration and the including up to the road communication device.

  Instead of creating the signal information including the transmission signal lamp color and the scheduled duration of the transmission signal lamp color by the traffic signal controller, the in-vehicle device may create the signal information. Thereby, not only the in-vehicle device can acquire accurate signal information, but also the processing load of the traffic signal controller can be reduced.

As described above, according to the road communication system according to the embodiment of the present application, by considering the time required for communication from when the signal information is created by the traffic signal device to when it is transmitted to the on-vehicle device, It is possible to provide accurate signal information.

It is a schematic diagram which shows the outline | summary of the road communication system containing the traffic signal controller which concerns on embodiment of this application . It is a block diagram which shows the structure of a traffic signal controller. It is a figure which shows the format of a signal control command. It is explanatory drawing which shows the example of the lighting time of each signal lamp color. It is explanatory drawing which shows the example of signal information. It is a figure which shows the example of the communication path | route from a traffic signal controller to a roadside apparatus. It is explanatory drawing which shows the example of the signal information after correction | amendment. It is a schematic diagram which shows the outline | summary of the road communication system containing the traffic signal controller which concerns on embodiment of this application . It is a block diagram which shows the structure of the vehicle-mounted apparatus and other apparatus which are mounted in the vehicle.

Embodiment 1:
Hereinafter, embodiments of the present application 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 an embodiment of the present application . The road communication system includes a traffic signal 1, a road device 2, an in-vehicle device 3, a central device 4, and the like. The central device 4 is a device that provides traffic information and the like, and is installed in a 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 a traffic signal 1 installed at each of a plurality of intersections via a communication line such as a telephone line. The traffic signal 1 is connected to a road device installed on each of a plurality of roads flowing into an intersection I including a road R via a communication line such as a telephone line.

  The traffic signal 1 includes a traffic signal controller 1a and a plurality of signal lamps 1b. The traffic signal controller 1a controls lighting, extinguishing and blinking of each signal lamp of the signal lamp device 1b. In addition, the traffic signal controller 1a receives traffic control information including traffic regulation information and a signal control command including information such as split from the central device 4. Further, the traffic signal controller 1a creates signal information including a signal lamp color and its duration by a process described later, and transmits the signal information to a plurality of road devices 2 connected to the traffic signal controller 1a together with the received traffic information. To do.

  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 has a communication function for performing communication with the central device 4 and communication with the road device 2. The communication unit 103 receives traffic information and a signal control command from the central device 4. In addition, the traffic information received and the generated signal information are transmitted to the road device 2 at a predetermined cycle (for example, 100 msec).

  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 device 2 is an optical beacon, a radio wave beacon, a DSRC (Dedicated Short Range Communication), a WiMAX (Worldwide interoperability for microwave access), and the like, and various kinds of devices are connected to the in-vehicle device 3 mounted on the vehicle 10. Wirelessly communicate information. The road device 2 includes a communication unit 2a that communicates various information with the in-vehicle device 3, and a communication control device 2b that controls the communication unit 2a. The communication control device 2b is provided with a storage unit such as a ROM, and information on the distance from the road device 2 to the intersection at the inflow destination of the road where the road device 2 is installed is stored in advance. For example, in the storage unit of the road device 2 installed on the road R, information on the distance from the road device 2 to the intersection I is stored in advance. In addition, the information of these distances is not limited to the structure memorize | stored previously, The structure acquired and memorize | stored from the central apparatus 4 grade | etc., May be sufficient. The road device 2 receives traffic information and signal information from the traffic signal device 1 and transmits these information and distance information to the in-vehicle device 3.

  The central device 4 transmits traffic information and signal control commands to a plurality of traffic signals at a predetermined cycle. FIG. 3 is a diagram showing a format of the signal control command. In the figure, split 1 indicates the split of current indication 1 and split 6 indicates the split of current indication 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 in-vehicle device 3 is mounted on the vehicle 10, and the in-vehicle device 3 wirelessly communicates various information with the on-road device 2. When the vehicle 10 equipped with the in-vehicle device 3 passes through the communication area Q (shaded portion) of the road device 2, the vehicle 10 performs wireless communication with the road device 2 and acquires traffic information, signal information, and distance information. .

  When the vehicle 10 acquires traffic information, signal information, and distance 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 I 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. The speed is reduced so that the vehicle can be stopped safely at the stop line P before the intersection I, and the vehicle stops at the stop line P. At that time, if the traffic information includes traffic regulation information related to the road R, 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 R, the vehicle 10 performs speed control so as not to exceed 40 km / h.

  Next, the procedure of signal information creation processing of the traffic signal controller 1a will be described. At the end of the cycle, the traffic signal controller 1a is configured to include the reference values of the splits 1 to 6 included in the signal control command stored in the storage unit 104, + variation values and −variation values, cycle lengths, levels, and respective indications. A signal control plan for the next cycle is created based on a constant representing the relationship between and the lighting time of each signal lamp color on each road flowing into the intersection I based on this signal control plan.

  FIG. 4 is an explanatory diagram showing an example of the lighting time of each signal lamp color on the road R. In the figure, the item number indicates the order of each signal lamp color displayed after the start of the cycle, the signal lamp color indicates the lamp color of the signal lamp 1b displayed for the vehicle traveling on the road R, and the lighting time indicates each signal lamp color. The number of seconds for lighting is shown. For example, the signal lamp color displayed first after the start of the cycle is blue, indicating that the lighting time is 60 seconds. The signal lamp color displayed third after the start of the cycle is blue arrow, and the lighting time is 10 seconds.

  In addition, the traffic signal controller 1a executes the subsequent processing every predetermined cycle (for example, 100 msec). First, the traffic signal controller 1a obtains the signal lamp color currently displayed (hereinafter referred to as the signal lamp color at the time of creation) and the elapsed time since the start of the signal lamp color at the time of creation. Based on the time and the lighting time of each signal lamp color, the signal lamp color at the time of creation and its duration T1, each signal lamp color scheduled to be displayed in the future (for example, up to one cycle ahead), and the signal information regarding the duration create.

  FIG. 5 is an explanatory diagram showing an example of signal information on the road R. The item number indicates the order of each signal lamp color displayed after the time when this signal information is created, the signal lamp color indicates the lamp color of the signal lamp 1b displayed for the vehicle traveling on the road R, and the duration indicates each signal lamp color. Each indicates the number of seconds that the color lasts. A signal lamp color with an item number of 1 indicates a signal lamp color at the time of creation. When the signal information is created, if the signal lamp color of item No. 1 in FIG. 4 is “blue” and the elapsed time is 40 seconds, the signal lamp color that is displayed first after the creation time, that is, created The time signal lamp color is blue, and its duration T1 is 20 seconds obtained by subtracting 40 seconds of elapsed time from 60 seconds of lighting time. In addition, the signal lamp color displayed for the second time and the duration thereof is the same as the signal lamp color for the item number 2 and thereafter in FIG. 4 and the lighting time thereof.

  Next, the traffic signal controller 1a transmits signal information to each on-road device 2 for each on-road device 2 installed on each road flowing into the intersection I, and then the on-road device 2 sends the signal to the in-vehicle device 3. On the other hand, a time ΔT required to transmit the signal information (hereinafter referred to as communication required time ΔT) is calculated. Specifically, the information size S of the signal information, the communication speed V (i) of the communication section i (i takes 1 to n) on the communication path to the roadside device 2, and each communication device on the communication path Based on the processing time P (j) of j (j takes 1 to m), the communication required time ΔT is calculated by Equation 1.

  For example, the case where two communication devices exist on the communication path from the traffic signal controller 1a to the road device 2 installed on the road R will be specifically described. FIG. 6 is a diagram illustrating an example of a communication path from the traffic signal controller to the road device. In the figure, there are two routers 5a and 5b on the communication path from the traffic signal controller 1a to the on-road device 2. The router 5a is the communication device 1, the router 5b is the communication device 2, the traffic signal controller 1a to the router 5a is the communication section 1, the router 5a to the router 5b is the communication section 2, and the router 5b to the roadside apparatus 2 is the communication section 3. And

  The information size S of the signal information is 100 bytes, the communication speed V (1) of the communication section 1 is 1200 bytes / second, the communication speed V (2) of the communication section 2 is 8000 bytes / second, and the communication speed V ( 3) is 1200 bytes / second, the processing time P (1) of the communication device 1 is 0.40 seconds, and the processing time P (2) of the communication device 2 is 0.42 seconds, the required communication time ΔT is about It is calculated as 1 second (= 100/1200 + 100/8000 + 100/1200 + 0.40 + 0.42).

  If the information size S, the communication speed V (i), and the processing time P (i) do not vary depending on the time zone, the communication required time ΔT is considered to be fixed. You may memorize | store and read this as it is. When the information size S is variable, a table storing the required communication time ΔT according to the information size S is stored in the storage unit 104 in advance, and the required communication time ΔT according to the information size S is read as it is. May be. Further, when the size of the header added for each communication section i is different, the information size S (i) is changed for each communication section i, and S in Equation 1 is replaced with S (i), and communication is required. What is necessary is just to calculate time (DELTA) T.

  Next, the traffic signal controller 1a transmits the signal information to the in-vehicle device 3 with respect to the first signal lamp color displayed in the signal information, the signal lamp color scheduled to be displayed after that, and the duration thereof. The required communication time calculated so as to coincide with the signal lamp color actually displayed on the signal lamp 1b (hereinafter referred to as the signal lamp color at the time of transmission), the signal lamp color scheduled to be displayed in the future, and the duration thereof. The signal information is corrected based on ΔT. That is, the corrected signal information represents the signal lamp color at the time of transmission and its duration, and each signal lamp color to be displayed in the future and its duration.

  Specifically, when the communication required time ΔT is equal to or less than the duration time T1 of the signal light color at the time of creation, the signal light color at the time of transmission is the same as the signal light color at the time of creation. Only the color duration T1 is replaced with (T1−ΔT) to obtain the duration of the signal lamp color at the time of transmission. On the other hand, when the required communication time ΔT exceeds the duration time T1 of the signal lamp color at the time of creation, the signal lamp color at the time of transmission is switched to the signal lamp color to be displayed next to the signal lamp color at the time of creation. The signal lamp color scheduled to be displayed next is set as the signal lamp color at the time of transmission, and the duration T2 of the signal lamp color scheduled to be displayed next is replaced with (T2− (ΔT−T1)) to continue the signal lamp color at the time of transmission. Time. When (T2− (ΔT−T1)) is a negative value, the signal lamp color at the time of transmission is switched to the signal lamp color scheduled to be displayed next, so that it is scheduled to be displayed next. The signal lamp color is set to the signal lamp color at the time of transmission, and the duration T3 of the signal lamp color scheduled to be displayed next is replaced with (T3− (ΔT−T1−T2)) to be the duration of the signal lamp color at the time of transmission. When (T3− (ΔT−T1−T2)) also becomes a negative value, the same processing is repeated thereafter.

  Here, a specific example of correction will be described using the example of signal information in FIG. FIG. 7 is an explanatory diagram illustrating an example of signal information after correction on the road R. (A) shows a case where the required communication time ΔT is 1 second, (b) shows a case where the required communication time ΔT is 22 seconds, and (c) shows a case where the required communication time ΔT is 26 seconds. The item number indicates the order of each signal lamp color displayed after this signal information is transmitted to the in-vehicle device 3, and the signal lamp color indicates the lamp color of the signal lamp 1b displayed for the vehicle traveling on the road R, The duration indicates the number of seconds each signal lamp color lasts. A signal lamp color with an item number of 1 indicates a signal lamp color during transmission.

  First, when the required communication time ΔT is 1 second, the required communication time ΔT is equal to or less than the duration T1 (= 20 seconds) of the signal lamp color (the signal lamp color at the time of creation) of item No. 1 in FIG. Is not corrected, and only the duration T1 of item number 1 in FIG. 5 is replaced from 20 seconds to 19 seconds.

  Next, when the required communication time ΔT is 22 seconds, the required communication time ΔT exceeds the duration T1 (= 20 seconds) of item number 1 in FIG. 5 and (the duration time of item number 2 in FIG. 5). T2− (communication required time ΔT−continuation time T1 of item number 1 in FIG. 5)) = ((4- (22-20)) = 2 and does not become a negative value, so item number 2 in FIG. The signal lamp color (the signal lamp color scheduled to be displayed next to the signal lamp color at the time of creation) becomes the signal lamp color of item No. 1 (signal lamp color at the time of transmission), and the duration T2 of item No. 2 is replaced from 4 to 2.

  Furthermore, when the communication required time ΔT is 26 seconds, the communication required time ΔT exceeds the duration T1 (= 20 seconds) of item number 1 in FIG. 5 and (the duration T2 of item number 2 in FIG. 5). − (Communication required time ΔT−continuation time T1 of item number 1 in FIG. 5)) = ((4- (26-20)) = − 2, which is a negative value and (term in FIG. 5) No. 3 duration T3- (communication required time ΔT-No. 1 duration T1 in FIG. 5-No. 2 duration T2 in FIG. 5)) = (10- (26-20-4)) = 8 Therefore, the signal lamp color of item No. 3 in FIG. 5 (the signal lamp color to be displayed next to the signal lamp color at the time of creation) in FIG. 5 is the signal lamp color of item No. 1 (the signal lamp color at the time of transmission) ), And the duration T3 of the item number 3 is replaced from 10 to 8.

  Thereby, the signal lamp color at the time of transmission in the signal information received by the in-vehicle device 3, the signal lamp color scheduled to be displayed in the future, and the duration thereof are the signal lamp device when the signal information is transmitted to the in-vehicle device 3. Since the signal lamp color actually displayed in 1b, the signal lamp color scheduled to be displayed in the future, and the duration thereof coincide with each other, accurate signal information can be provided to the in-vehicle device 3. Further, the vehicle 10 can perform appropriate speed control by performing the above-described safe driving support control processing based on the corrected signal information.

Strictly speaking, the time point when the road device 2 transmits the corrected signal information to the in-vehicle device 3 and the time point when the signal information reaches the in-vehicle device 3 are the sections from the road device 2 to the in-vehicle device 3. Therefore, the duration of the signal lamp color at the time of transmission in the signal information received by the in-vehicle device 3 and the duration of the signal lamp color actually displayed on the signal lamp 1b at the time of arrival are as follows. There will also be a shift. However, since the communication time in the section from the road device 2 to the in-vehicle device 3 is as short as 1 msec when the road device 2 is an optical beacon, the above deviation can be almost ignored. Therefore, the road communication system according to the embodiment of the present application can provide accurate signal information to the in-vehicle device 3.

  Of course, the on-road device so that the duration of the signal lamp color at the time of transmission in the signal information received by the in-vehicle device 3 and the duration of the signal lamp color actually displayed on the signal lamp device 1b at the time of arrival are the same. The communication required time ΔT may be obtained by further adding the communication time in the section from 2 to the in-vehicle device 3. Thereby, the accuracy of the signal information can be further improved. Further, if there is a communication time inside the in-vehicle device 3 or the vehicle 10, these may be added to obtain the required communication time ΔT.

  In addition, it is thought that the signal information transmitted with respect to the road apparatus 2 from the traffic signal controller 1a is transmitted for every predetermined period (for example, 100 msec). In this case, when the signal information is transmitted to the in-vehicle device 3 as it is after 50 msec from when the road device 2 receives the signal information, the duration of the signal lamp color recognized by the in-vehicle device 3 is 50 msec with respect to the actual duration. An error is generated. Therefore, the road device 2 may subtract 10 msec from the duration every time 10 msec elapses, for example, from the time when the signal information is received until the next signal information is received. Then, a more accurate time can be provided in units of 10 msec. For example, if there is a limitation on the bandwidth of the communication line between the traffic signal controller 1a and the roadside device 2, the signal information transmission cycle may be set to 1 second or the like. In such a case, it is very effective when the road device 2 reduces 10 msec from the duration as described above.

  Further, the road device 2 may not only reduce the duration time but also update the signal lamp color at the time of transmission and the signal lamp color scheduled to be displayed in the future. For example, when the traffic signal controller 1a transmits signal information to the road device 2 every 10 seconds, and the road device 2 decreases the duration by 1 second every 1 second after receiving the signal information, When the device 2 receives the signal information received from the traffic signal controller 1a, the signal light color at the time of transmission, the signal light color scheduled to be displayed in the future, and the duration thereof are blue 7 seconds, yellow 4 seconds, red 42 seconds, and so on. Suppose there was. When 1 second has elapsed since the reception, the road device 2 reduces the blue duration by 1 second, and transmits signal information such as blue 6 seconds, yellow 4 seconds, red 42 seconds,. When 6 seconds elapse, the blue duration is reduced by 6 seconds, and signal information of blue 1 second, yellow 4 seconds, red 42 seconds,... Is transmitted to the in-vehicle device 3. When 7 seconds have elapsed, the signal lamp color at the time of transmission is updated from blue to yellow, and signal information of yellow 4 seconds, red 42 seconds,... Is transmitted to the in-vehicle device 3. In this way, the traffic signal controller 1a does not need to transmit signal information to the on-road device 2 in a short cycle, so that the processing load on the traffic signal controller 1a can be reduced and the traffic signal controller 1a. The communication load between the road device 2 and the road device 2 can be reduced.

  FIG. 1 is a schematic diagram showing an outline of a road communication system when the road device 2 is a narrow-area communication device such as an optical beacon, but a schematic diagram when the road device 2 is a wide-area communication device such as WiMAX. The figure is as shown in FIG.

  In the configuration shown in FIG. 8, since the road device 2 and the in-vehicle device 3 can communicate continuously until the vehicle 10 reaches the intersection I, the in-vehicle device 3 always receives the latest signal information. Can be useful.

Embodiment 2:
In the first embodiment described above, the traffic signal controller 1a calculates the communication required time ΔT based on the information size S of the signal information, the communication speed of the communication section on the communication path, and the like. For example, the required communication time ΔT can be directly measured.

  Hereinafter, a procedure in which the traffic signal controller 1a measures the communication required time ΔT will be described. First, the traffic signal controller 1 a transmits predetermined data having a fixed size (hereinafter referred to as dummy data) to the road device 2. When receiving the dummy data, the road device 2 transmits predetermined data (hereinafter referred to as response data) having a fixed size to the traffic signal controller 1a. When the traffic signal controller 1a receives the response data, the traffic signal controller 1a calculates a required time from the transmission of the dummy data to the reception of the response data, and estimates half of the required time as the communication required time ΔT. Thereby, the accuracy of the signal information provided to the in-vehicle device 3 can be further improved.

  Alternatively, the measured communication time ΔT may not be used as it is, and the above measurement may be performed periodically, and an average of the obtained measurement values may be used as the communication time ΔT.

Embodiment 3:
In the above-described first and second embodiments, the traffic signal controller 1a determines the signal light color at the time of creation, the signal light color scheduled to be displayed in the future, and the signal information including these durations based on the communication required time ΔT. It corrected, the signal lamp color at the time of transmission, the signal lamp color scheduled to be displayed in the future, and their durations were created, and the signal information after this correction was transmitted to the in-vehicle apparatus 3 through the road device 2, For example, the traffic signal controller 1a creates signal information including a signal lamp color at the time of creation, a signal lamp color scheduled to be displayed in the future, and their duration and communication required time ΔT. Information is transmitted to the in-vehicle device 3 through the road device 2, and the signal light color at the time of creation and the signal light color scheduled to be displayed in the future included in the signal information received by the in-vehicle device 3 and the duration thereof are as follows: Correction may be performed based on the required communication time ΔT included in the signal information, and the signal lamp color at the time of transmission, the signal lamp color scheduled to be displayed in the future, and the duration thereof may be calculated.

  FIG. 9 is a block diagram showing the configuration of the in-vehicle device 3 and other devices mounted on the vehicle 10. The GPS processing unit 301 receives a GPS signal from a GPS satellite, and measures the position (latitude, longitude, and altitude) of the vehicle 10 based on time information included in the GPS signal, an orbit of the GPS satellite, and positioning correction information. . 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 a signal lamp color at the time of creation, a signal lamp color scheduled to be displayed in the future, a duration time thereof, and a communication required time ΔT. Further, the communication unit 304 controls the received traffic information, the distance information, the signal lamp color at the time of transmission calculated by the processing unit 308 based on the signal information, the signal lamp color scheduled to be displayed in the future, and the information on the duration thereof. Output to the unit 1005.

  The storage unit 305 stores road map data, various types of information received by the communication unit 304, a signal lamp color at the time of transmission calculated by the processing unit 308, a signal lamp color scheduled to be displayed in the future, information on the duration thereof, 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. Further, the processing unit 308 converts the signal lamp color at the time of creation included in the signal information received by the communication unit 304, the signal lamp color scheduled to be displayed in the future, and the duration thereof into the required communication time ΔT included in the signal information. Based on the correction, the signal lamp color at the time of transmission, the signal lamp color scheduled to be displayed in the future, and the duration thereof are calculated. Since this calculation method is the same as the signal information correction method in the traffic signal controller 1a described in the first embodiment, description thereof is omitted.

  The travel control unit 1005 is composed of one or a plurality of microcomputers. The traffic information acquired from the communication unit 304, the distance information, the signal light color at the time of transmission, the signal light color scheduled to be displayed in the future, and the duration of these times Based on the information and the speed data of the vehicle 10 acquired from the vehicle speed sensor 1001, the safe driving support control process is performed. That is, it is determined whether or not the intersection I can be safely passed in blue. If it is determined that the intersection I can be passed, the drive unit (engine) 1006 is controlled to maintain the current speed. When 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 I, 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 106 and the braking unit 107 are controlled in consideration of the traffic regulation.

  Thus, the processing load of the traffic signal controller 1a can be reduced by calculating the signal lamp color at the time of transmission, the signal lamp color scheduled to be displayed in the future, and the duration thereof.

  In the above-described embodiment, the traffic signal controller 1a and the road 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 device are provided. 2 may be configured to be housed in one housing. In this case, the exchange of information between the traffic signal controller 1a and the on-road device 2 may be performed using any of wired, wireless, and internal buses.

  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.

DESCRIPTION OF SYMBOLS 1 Traffic signal device 1a Traffic signal controller 1b Signal lamp 101 Control part 102 Lamp drive part 103 Communication part 104 Storage part 2 Roadside apparatus 2a Communication part 2b Communication control apparatus 3 Car-mounted apparatus 301 GPS processing part 302 Direction sensor 303 Vehicle speed acquisition part 304 Communication unit 305 Storage unit 306 Display unit 307 Audio output unit 308 Processing unit 4 Central devices 5a and 5b Router 10 Vehicle 1001 Vehicle speed sensor 1002 Monitor 1003 Speaker 1005 Travel control unit 1006 Drive unit 1007 Braking unit I Intersection P Stop line Q Communication region R road

Claims (6)

Including a traffic signal controller having signal information creating means for creating signal information including information relating to a schedule for switching the signal lamp, and a road communication device having road-to-vehicle communication means for transmitting the signal information to the in-vehicle device, A road communication system configured to communicate between the traffic signal controller and the road communication device ,
The signal information includes a transmission signal lamp color displayed at a time when the road-to-vehicle communication unit is scheduled to transmit the signal information, and a scheduled duration of the transmission signal lamp color.
The signal information creation means includes a duration time from the creation time of the creation signal lamp color displayed at the time when the signal information is created and a communication required time from the traffic signal controller to the road communication device. Based on, is configured to determine the transmission signal lamp color and the scheduled duration time,
If the required communication time does not exceed the duration, the signal information creating means determines the signal lamp color at the time of transmission as the signal lamp color at the time of creation and sets the scheduled duration from the duration to the required communication time. Is determined by subtracting
Road on the communication system. Including a traffic signal controller having signal information creating means for creating signal information including information relating to a schedule for switching the signal lamp, and a road communication device having road-to-vehicle communication means for transmitting the signal information to the in-vehicle device, A road communication system configured to communicate between the traffic signal controller and the road communication device,
The signal information includes a transmission signal lamp color displayed at a time when the road-to-vehicle communication unit is scheduled to transmit the signal information, and a scheduled duration of the transmission signal lamp color.
The signal information creation means includes a duration time from the creation time of the creation signal lamp color displayed at the time when the signal information is created and a communication required time from the traffic signal controller to the road communication device. Based on, is configured to determine the transmission signal lamp color and the scheduled duration time,
The signal information creating means determines the signal lamp color at the time of transmission to be a future signal lamp color to be displayed in the future rather than the signal lamp color at the time of creation when the required communication time exceeds the duration time, and the scheduled duration time In determining the duration, the time required for communication, and the display time of the future signal lamp color,
Road communication system. The traffic signal controller further includes communication time calculation means for calculating the communication required time,
  The communication time calculating means includes
  In the calculation of the required communication time, the communication speed in one or a plurality of communication sections from the traffic signal controller to the road communication device, 1 through the traffic signal controller to the road communication device, or 1 Using information relay processing time in a plurality of transit devices and the size of the signal information,
The road communication system according to claim 1 or 2. The traffic signal controller is
  Dummy information transmitting means for creating dummy information having a predetermined size and transmitting it to the roadside communication device;
  Further comprising communication time measuring means for measuring the required communication time,
  The roadside communication device further includes dummy information return means for receiving the dummy information, creating dummy response information for the dummy information, and returning the dummy response information to the traffic signal controller,
  The communication time measuring means includes
  In the measurement of the required communication time, a period from when the dummy information is transmitted until the dummy response information is received is used.
The road communication system according to claim 1 or 2. The traffic signal controller is configured to transmit the signal information to the road communication device every predetermined first period,
  The roadside communication device further includes an updating unit that updates the signal information every time a predetermined second period shorter than the first period elapses from the reception time point when the signal information is received.
The road communication system according to any one of claims 1 to 4. The traffic signal controller used for the road communication system of any one of Claims 1-5.

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