JP4849022B2 - Traffic system and traffic signal controller - Google Patents

Description

  The present invention relates to a traffic system that provides signal information related to display of a signal lamp to an in-vehicle device.

In traffic signal control, a table control method is widely used in which a signal control plan for lighting each signal lamp color is created for each cycle, and a signal lamp is controlled according to the signal control plan.
One cycle means that the display of the traffic signal is completed, and the cycle length indicates the time required for one cycle. In the case of traffic lights installed at intersections, the start of the green light display on the main road side is regarded as the start time of one cycle, and the period from when the signal display is completed until the next green signal display on the main road side is started. Often one cycle. Further, the cycle length is often set to about 90 seconds to 150 seconds, and is changed as needed according to traffic conditions and time zones.

In the table control system, the traffic signal controller usually creates a signal control plan for the one cycle immediately before the start of one cycle, and the signal lamp is displayed according to the signal control plan.
In this case, the traffic signal controller creates a signal control plan based on signal control command information sent from a central device such as a signal control device installed in the traffic control center. The central device can transmit the signal control command information at any time, and the traffic signal controller can receive the signal control command last received from the central device at the time of signal control plan creation (a time immediately before the start of one cycle). Adopt information. The signal control plan is created in consideration of not only the signal control command information but also the values of various parameters stored in advance in the traffic signal controller.

In recent years, with the aim of promoting traffic safety and preventing traffic accidents, a system that improves the safety of vehicles by receiving information from infrastructure devices installed on the road and utilizing the information has been studied. ing.
As such a system, for example, a safe driving support system is proposed in which operation information of a traffic light is wirelessly transmitted to a vehicle, and the vehicle performs brake control according to a remaining display time of a green signal included in the operation information ( Patent Document 1).

Japanese Patent No. 2806801

In the table control method, since the traffic signal controller creates the signal control plan for the one cycle immediately before the start of one cycle, the time until the future time is reached by the time corresponding to the cycle length at the start of the one cycle. The display schedule of traffic lights has been decided, but it has not been decided after that.
That is, in the operation information (hereinafter referred to as signal information) of the traffic light in the safe driving support system, for example, “blue: 65 seconds, yellow: 5 seconds, red: 50 seconds”, etc. for one cycle. However, the display schedule of the traffic lights after the end of the one cycle is uncertain.

  In this case, at the start of one cycle, a display schedule (information about the future from about 90 seconds to about 150 seconds) can be provided to the vehicle after the time corresponding to the one cycle has elapsed. At the time point just before the end of the one cycle, there is almost no fixed information, and useful signal information cannot be provided to the vehicle.

For example, in the case of one cycle starting from the start of the green light on the main road, the signal information provided to the vehicle traveling toward the intersection on the main road just before the end of the cycle (for example, 3 seconds before the end) , “The currently displayed lamp color is a red signal and its duration is 3 seconds” has only been determined, and the duration of the next green signal to be displayed is undecided. is there.
Therefore, for example, when a vehicle that is expected to arrive at an intersection after about one minute has received the signal information, the display time of the green light is unknown, so whether the vehicle can safely pass through the intersection or must stop There is a problem that it cannot be judged.

On the other hand, in the case of one cycle starting from the start of the green light on the main road, the current display is shown for vehicles traveling on the road toward the intersection just before the end of the cycle (for example, 3 seconds before the end). Even the red light duration that is being done cannot be provided.
This is because, on the secondary road side, both the signal lamp color displayed at the end of one cycle and the signal lamp color displayed at the beginning of the next cycle are red signals, so the display schedule of the next cycle is unknown. This is because even the duration of this red signal cannot be determined.
For this reason, there is a problem that the display of the signal lamp color at the time of arrival at the intersection cannot be predicted even for a vehicle traveling on the secondary road toward the intersection.

  In order to solve such a problem, the present inventor pre-creates a signal control plan for one cycle at the time before the start of the previous one cycle immediately before the first cycle or at the time when the previous one cycle is executed approximately in half. Have been invented (Japanese Patent Application No. 2007-110147 and Japanese Patent Application No. 2007-119074).

In the above method, since the signal control plan for one cycle is created at an early stage, the duration of more signal light colors can be determined as compared with the conventional method, and at the point just before the end of one cycle. However, it has become possible to determine signal information up to a certain point in the future. However, if a signal control plan is created first at a time before a predetermined period from the start of one cycle, the real-time property of the signal control is reduced accordingly.
Thus, since the determinism of the signal information and the real-time property of the signal control are in a trade-off relationship, it is more desirable to be able to change the time point for creating the signal control plan at any time in consideration of the benefits of both. .
Therefore, an object is to provide a traffic system or the like that can change the signal control plan creation time point.

  In the traffic system according to the first aspect of the invention, the signal control plan for one cycle is within the plan creation period corresponding to the period from the start time of the immediately preceding one cycle immediately before the one cycle to the end time of the immediately preceding one cycle. Based on the signal control plan creation means created at any point of time, the signal lamp control means for switching each signal lamp color in the one cycle in accordance with the created signal control plan, and the created signal control plan A traffic signal controller having signal information generating means for generating signal information relating to the display of the current and future signal lamps, and a transmission means for transmitting the signal information to a predetermined area on a road, The plan creation means determines when the signal control plan of one cycle is within the plan creation period at the time immediately before the start of the plan creation period. And determining whether to create in (Claim 1).

In the present invention, after a predetermined width is given to a period for creating a one-cycle signal control plan, when the plan creation period starts, at which point in the plan creation period the plan is created It was decided beforehand.
As a result, for example, the situation in which the traffic system should emphasize real-time signal control in response to an increase in traffic demand or traffic congestion, and the situation in which signal information determinism should be emphasized to prevent traffic accidents alternately In such a case, it is possible to change the operation timing of the signal control plan at any time and operate it, which is very useful.

  In this case, the signal control plan creation unit is configured to select and determine a signal control plan creation time from a plurality of candidates, and the plurality of candidates include a start time of the plan creation period, the period It is preferable to include at least three time points of approximately the middle time point and the end time point of the period (claim 2).

  If the method of creating a signal control plan at the start of the plan creation period, signal information is more deterministic and contributes to prevention of traffic accidents. At the end of the period, the signal control is improved in real time and traffic flow is improved. It contributes to facilitation, and the interests of both can be adjusted at approximately the middle point of the period. In other words, if the signal control plan creation time is selected from a plurality of candidates including at least these three candidates, the system is appropriately switched according to the interests of traffic accident prevention and traffic flow smoothing. It becomes possible.

Further, the traffic system of the present invention comprises signal control command creating means for creating signal control command information used for creating the signal control plan, and command transmitting means for transmitting the signal control command information to the traffic signal controller. The signal control device may further comprise a signal control device, in which case the signal control device gives the traffic signal controller an instruction as to when to create a signal control plan within the plan creation period, It is preferable that the traffic signal controller determines a signal control plan creation time according to the instruction (claim 3).
Furthermore, it is good to provide the traffic condition acquisition means which acquires the traffic condition around the installation point of the said traffic signal controller, and the said plan creation time instruction | indication means gives an instruction | indication according to the traffic condition (Claim 4). .

In a traffic system, it is more advantageous to systematically control a plurality of traffic signal controllers in terms of smoothing traffic flow. Therefore, if a signal control device controls a traffic signal controller, it can be further improved. It is possible to realize signal control in accordance with traffic conditions.
In this case, it is better that the signal control device capable of collecting the micro and macro traffic conditions intensively manages and gives instructions regarding the signal control plan creation time.
For example, if the traffic signal controller makes an individual decision, if there is a variation in the judgment, even if the traffic signal controller at a certain intersection decides to prioritize traffic flow smoothing, This is because if the controller decides to neglect traffic flow smoothing, the effect of traffic flow smoothing will be halved.
The given instruction can be switched according to, for example, a time zone, but preferably switched according to the traffic situation. If the time zone where traffic accidents and traffic jams are likely to occur is fixed, switching the system according to the time zone is also effective, but in most cases it depends on the irregular events and weather that occur in the vicinity. Therefore, it is desirable to give an instruction after determining an appropriate operation method for each traffic situation.

In this case, the traffic situation to be acquired may be, for example, the amount of traffic flowing into an intersection or the length of a traffic jam. However, after acquiring the vehicle travel speed, the plan creation time instruction means gives an instruction according to the vehicle travel speed. It is preferable to do so (claim 5).
This is because the vehicle traveling speed is an index that directly indicates both the probability of occurrence of a traffic accident and the smoothness of the traffic flow.

In addition, when the timing for giving the instruction is every cycle, if the vehicle traveling speed has improved compared to the vehicle traveling speed at the time when the previous instruction was given, the signal control plan creation time is set to the previous instruction. It is better to give an instruction to make the time earlier than (Claim 6).
As the traveling speed increases, the approach speed at which the vehicle approaches the traffic light also increases, so it is considered that the probability of a traffic accident occurring at the time of switching the signal light color is increased, and for the purpose of increasing the determinism of signal information This is because the advancement of the signal control plan creation time contributes to the prevention of traffic accidents.

  The traffic signal controller preferably further comprises notification means for creating notification information about the time when the signal control plan creation means creates the signal control plan and notifying the signal control device (Claim 7). The signal control device may determine a transmission time point of the signal control command information based on the notification information.

  The traffic signal controller notifies the signal control device of the notification information regarding the signal control plan creation time point, so that the traffic signal controller correctly determines the signal control plan creation time point according to the instruction given by the signal control device itself. In addition to confirming the timing of the traffic signal controller creating a signal control plan in response to the notification, if the signal control command information is transmitted from the signal control device, the real-time performance of the signal control This is because of the increase.

In this case, the signal control device predicts a traffic situation at a future time point when the signal lamp color is actually controlled according to a signal control plan created using the signal control command information, and responds to the predicted traffic situation. It is even better if the signal control command information is created (claim 9).
This is because, according to the present invention, there is a case where the signal control plan is determined in advance a predetermined time before the cycle start time, so the signal control command information to be sent is not the actual traffic situation at the present time but the actual traffic situation. This is because the signal control command information that is more suitable for the actual situation can be implemented by adopting the signal control command information and creating it based on the predicted traffic situation at the start of the cycle in which the control is performed.

  Needless to say, the traffic signal controller used in the traffic system according to the first invention is useful (claim 10).

  In addition, the traffic signal controller according to the second aspect of the invention creates a signal control plan for one cycle from the time immediately before the start of the previous cycle immediately before the previous cycle to the end of the previous cycle. A signal control plan creation means created at any point in time, a signal lamp control means for switching each signal lamp color in the one cycle according to the created signal control plan, and a created signal control plan Based on the above, signal information creating means for creating signal information related to the display of the current and future signal lamps, output means for outputting the signal information to the outside, and traffic condition acquisition means for acquiring traffic conditions, The signal control plan creation means is a one-cycle signal control plan according to the acquired traffic situation at a time immediately before the start of the plan creation period. It is configured to determine whether to create at what point in the plan creation time (claim 11).

  In the second invention, since the traffic signal controller is provided with the traffic condition acquisition means, the signal control plan can be appropriately selected according to the traffic condition by using only one traffic signal controller as in the first traffic system. The creation time can be determined.

  In this case, the signal control plan creation means is configured to select and determine a signal control plan creation time point from a plurality of predetermined candidates, and the plurality of candidates include a start time of the plan creation period, In addition, it is preferable to include at least two time points at the end of the period (claim 12).

  If the method of creating a signal control plan at the start of the plan creation period, signal information is more deterministic and contributes to prevention of traffic accidents. At the end of the period, the signal control is improved in real time and traffic flow is improved. Contributes to facilitation. In other words, if the signal control plan creation time is selected from a plurality of candidates including at least these two candidates, the system is appropriately switched according to the interests of traffic accident prevention and traffic flow smoothing. It becomes possible.

  As described above, according to the traffic system and traffic signal controller of the present invention, it becomes possible to freely switch the creation time point of the signal control plan according to the time zone, traffic conditions, etc. Traffic signal control can be performed in view of the benefits of both the reliability and signal information determinism.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an outline of equipment arrangement of a traffic system according to the present invention, and includes a traffic signal controller 1A, a signal controller 5, a vehicle C, and an in-vehicle device 6 mounted on the vehicle C. FIG. 3 is a block diagram showing functional blocks of the traffic signal controller 1A.

[Overall system configuration]
On the road R connected to the intersection A, a stop line P is drawn before the intersection A.
A traffic signal controller 1A is installed at the intersection A. One or a plurality of vehicles traveling toward the intersection A by turning on, turning off, and blinking the signal lamp colors of the signal lamps including the signal lamp 2Aa (see FIG. The presence or absence of the right of traffic is displayed for the vehicle C including the vehicle C).

The traffic signal controller 1A has a built-in transmitter 7 (FIG. 3) for wirelessly transmitting communication data to the vehicle, and communicates from the communication antenna 1Aa connected to the transmitter toward the road R. Data is sent. The vehicle C traveling on the road R can receive the communication data transmitted via the communication antenna 1Aa in the communication area Q (a range indicated by hatching in FIG. 1).
For roads other than the road R connected to the intersection A, the vehicle traveling on the road can receive the communication data of the traffic signal controller 1A with the same configuration.

The communication data transmitted to the communication area Q includes signal information related to the display lamp color of the signal lamp 2Aa controlled by the traffic signal controller 1A and the schedule of the number of continuous seconds.
The signal information here stores, for example, the duration of the currently displayed green signal, the display order of the yellow signal, the right turn arrow, the red signal, and the like to be displayed thereafter, the scheduled duration thereof, and the like. Note that the signal information includes display schedule information for more traffic lights than for one cycle. In addition, the point in time when the display of the green light for the vehicle traveling on the road R toward the intersection A is started as the cycle start point.
The communication data includes road shape information related to the shape of the road such as the number of lanes and gradient of the road R, road surface state information for notifying the road surface state of the road R, and the like.

The transmitter 7 may not be built in the traffic signal controller 1A. For example, the transmitter 7 is installed on the road R as an independent road device (for example, an optical beacon or a DSRC road machine). May be used.
In this case, the traffic signal controller 1A may transmit the created signal information and the like to the road device separately through a communication line or the like.
The signal information and the like may be in any format. For example, the signal information and the road shape information may be combined into one information, or conversely, the signal information may be a plurality of information of two or more. . A transmitter may be prepared for each type of data to be transmitted, and signal information and road shape information may be transmitted from different transmitters.

On the other hand, a signal control device 5 is installed in the traffic control center, and exchanges information with the traffic signal controller 1A through the router 4 and the communication line.
The traffic signal controller 1A creates a signal control plan based on the signal control command information from the signal control device 5, and functions such as lighting each signal lamp color such as the signal lamp 2Aa based on the created signal control plan Have
The signal control command information here includes, for example, information on the time or ratio of the green light to be assigned to each of the main road and the secondary road, cycle length, point sensitive control (for example, right turn sensitive control, bus sensitive control and dilemma). Information regarding whether or not to perform sensitivity control or the like may be stored.

The vehicle C traveling on the road R has a function of receiving the signal information and performing a safe driving support operation.
The safe driving support operation here is based on the signal information, road shape information, etc., and predicts the display state of the traffic light when the vehicle C passes the stop line P. When it is predicted that the vehicle is stopped, it means that the brake is automatically controlled to stop the vehicle before the stop line P, or that the driver is warned to stop.
Note that all the vehicles traveling on the road R do not have to have the function of the safe driving support operation, and the function may be stopped even if the vehicle has the function.

[Contents of signal information]
FIG. 2 shows an example of the signal information.
(A) is an example of the basic structure of signal information, and shows that it is composed of a header part, a data part, and a footer part.
(B) is an example which shows the detail of information.

The header portion stores the data size of the signal information and the number of lamp colors (08) that the traffic signal controller 1A provides information to the vehicle, and displays the display lamp colors in the subsequent areas. The estimated number of seconds is stored for the number of lamp colors.
A CRC, SUM value, and the like are stored in the footer part.

Further, the data portion stores the scheduled number of seconds of lamp color display corresponding to the number of lamp colors stored in the header portion. In this example, the currently displayed signal lamp color is a blue signal (code “01”), the scheduled display time is 22 seconds (“16” in hexadecimal), and the yellow signal is displayed next to the blue signal. (Code “02”), the display scheduled number of seconds is 8 seconds (“08” in hexadecimal), and the right turn arrow (code “13”) is displayed next to the yellow signal, and the display scheduled number of seconds. The number is 10 seconds (hexadecimal “0A”), the right turn arrow displays the red signal (code “03”), and the scheduled display time is 64 seconds (hexadecimal “40”). It is shown that.
The scheduled display seconds may be expressed in units of 100 ms or 10 ms. If the scheduled display seconds are unknown, “FF” indicating that the number of seconds is unknown may be stored at the number of seconds.

  When more display schedules than one cycle are stored in the signal information of the present invention, normally, in the signal color number field of the signal information transmitted to the main road side, one cycle is executed. A value larger than the number of signal lamp colors to be displayed is set. Further, in the signal information transmitted to the secondary road side, the signal lamp color (red signal) displayed at the start of the cycle and at the end of the cycle is the same, so the number of signal lamp colors displayed during one cycle is the same. Or a larger value is set.

In traffic signal control, a flashing display (a yellow flashing signal on the main road side and a red flashing signal on the secondary road side) may be performed at night when traffic volume is low. Not necessarily the same.
The signal information may store information for two cycles or more, or may be information for just one cycle. Further, there may be a case in which some of the signal information is unconfirmed.

[Basic operation of traffic signal controller]
Hereinafter, the basic operation of the traffic signal controller 1A will be described with reference to FIGS.

  The traffic signal controller 1A exchanges information with the signal control device 5 through a communication line, a router, etc., and the central device information receiving means 131 receives signal control command information transmitted from the signal control device 5.

  The signal control plan creation means 101 of the traffic signal controller 1A does not create a signal control plan for the next cycle immediately before the start of one cycle (hereinafter referred to as the next cycle) as in a conventional traffic signal controller. , Between the time immediately before the start of the cycle immediately before the next cycle (currently executed cycle, hereinafter referred to as the current cycle) and the end of the current cycle (hereinafter referred to as the plan creation period). Create a signal control plan for the next cycle at some point.

At which point in time during the plan creation period the signal control plan for the next cycle is created is determined at the start of the plan creation period. That is, the creation time of the signal control plan for the next cycle is determined in advance at the start time of the plan creation period, and when the creation time comes, the next signal control command information is reached based on the last signal control command information arrived up to that time. Determine the signal control plan for the cycle.
That is, a plan creation time point for creating a signal control plan of one cycle is determined before the cycle immediately before that cycle is started, and a signal control plan is created when the plan creation time point comes.

FIG. 4 is a diagram showing a procedure for determining the timing for creating the signal control plan.
Note that a cycle before the current cycle is called a previous cycle.
Here, the plan creation period of the next cycle is defined from the time just before the end of the previous cycle to the time just before the end of the current cycle. In this case, this plan creation period may be set as long as it is until the start of the next cycle, but the length of the period is generally the same as or longer than the execution period of this cycle. A slightly longer degree is preferable, and the end of the period is preferably immediately before the start of the next cycle.

At the time when the plan creation period of the next cycle starts, first, the plan creation time determination means 141 of the traffic signal controller 1A determines the plan creation time (T1) of the next cycle ((1) in FIG. 4).
In this case, when T1 is determined, if there is an instruction from a central device such as the signal control device 5, it may be determined according to the instruction, or the traffic signal controller 1A itself may store traffic conditions and constants stored in advance in the storage unit. It may be determined based on the above. Moreover, you may make it switch simply according to a time slot | zone.
At this time, the determined plan creation time (T1) is notified to the signal control device 5 by the plan creation time notifying means 151. At this time, the same information may be notified to other adjacent traffic signal controllers.
Further, the plan creation time notification means 151 has information (signal control command information of signal control command information) indicating that the timing for creating the signal control plan is approaching when the plan creation time (T1) is approaching (for example, several seconds before T1). Information for prompting transmission) may be transmitted. Normally, since the signal control device 5 controls a plurality of traffic signal controllers at the same time, the signal control device 5 autonomously tries to grasp the appropriate transmission timing of the signal control command information for each traffic signal controller. However, the function of the signal control device 5 is complicated, but the signal control device 5 can make traffic signal control by spontaneously notifying the timing of transmitting the signal control command information from the traffic signal controller 1A side. This makes it possible to easily and accurately grasp the appropriate transmission point of the signal control command information for each machine, which is very effective.

Next, when the plan creation time (T1) is reached during execution of the previous cycle or the current cycle, the signal of the next cycle is determined based on the signal control command information last received from the signal control device 5 at that time. A control plan is created ((2) in FIG. 4). The created signal control plan is stored in the next signal control plan table 103 ((b) of FIG. 5). In this case, the current signal control plan table 102 already stores the signal control plan of the current cycle being executed ((a) in FIG. 5).
When this cycle is completed, the contents of the next signal control plan table 103 are copied to the current signal control plan table 102, and then the signal lamp control means 111 stores the next cycle signal stored in the current signal control plan table 102. The signal lamp 2Aa and the like are controlled in the order and duration of the states 1 to 7 in the control plan, and lighting and extinguishing of each signal lamp color in the next cycle is started ((3) in FIG. 4).

As described above, since the creation point of the signal control plan for the cycle can be determined for each cycle, the signal control plan for the next cycle can be created immediately before the start of the next cycle as in the past, It is also possible to create a signal control plan for the next cycle at the start of this cycle or at any time during the execution of this cycle.
With this method, the plan creation time can be switched for each cycle, so if there is a lot of traffic and the real-time performance of signal control should be emphasized, the plan creation time will be set at the end of the plan creation period or just before the end. It is possible to realize flexible and advanced system operation such as setting the plan creation time in the first half of the plan creation period when the traffic volume is low and the average traveling speed of the vehicle improves. It was.

  The plan creation period of the next cycle may be, for example, from the start to the end of the cycle, or from the time 10 seconds before the end of the cycle to the end. Further, the length may be less than one cycle, such as a period from the time point 10 seconds after the cycle start to the end of the cycle, or a period corresponding to substantially the latter half of the cycle.

[Notification to signal control device by traffic signal controller]
As described above, the plan creation time notification means 151 of the traffic signal controller 1A transmits information about the plan creation time to the signal control device 5 and the like. In this case, information that prompts the signal control device 5 or the like to transmit signal control command information may be transmitted when the timing for creating the signal control plan approaches.

For example, when notifying the time point when the signal control plan for the next cycle is created, it is preferable to simultaneously notify information related to the signal control plan for the current cycle that has already been determined at the time of notification.
However, since it is after the end of the current cycle that the signal lamp is actually controlled according to the signal control plan for the next cycle that will be decided soon, if the contents of the control of this cycle are known, The signal control device 5 can more accurately predict the traffic situation at the start of the next cycle, and by creating the signal control command information according to the accurate prediction, the actual traffic can be further increased. This is because appropriate traffic signal control according to the situation can be performed.
It should be noted that the information regarding the signal control plan of the current cycle that has already been determined may be sequentially transmitted when the signal control plan is created, and may not necessarily be simultaneously with the notification of the creation timing.

[Creation of signal information by traffic signal controller]
Further, the signal information creating unit 121 creates signal information for a period longer than one cycle based on the current signal control plan table 102 and the next signal control plan table 103 at every predetermined period (for example, every second). . The generated signal information is transmitted to the communication area Q through the transmitter 7.
In this case, the “scheduled display time for the currently displayed signal lamp color (1)” included in the signal information is reduced as time passes and is currently displayed when it reaches 0 seconds. Is replaced with the next signal color.

The signal information to be created may be information for two cycles or may include more information than for two cycles. For example, if the signal control plan for the next cycle is created immediately after the start of this cycle or at a time before the start of this cycle, the duration of the signal light color for two cycles or more can be determined. The vehicle side may be provided with information up to a distant future.
In addition, the signal information to be provided can be customized for each point in consideration of the amount of data and the road-to-vehicle communication band. For example, if the cycle length is set to be long enough, in addition to the information for one cycle, just providing one or two more signal light color durations to the future far enough Information. In this way, by reducing the amount of signal information data to the required limit, the amount of road-to-vehicle communication information can be reduced, the reliability of data arrival to the vehicle side can be improved, and the communication band can be used efficiently Is possible.

  The traffic signal controller 1 </ b> A is used when the traffic signal controller 1 </ b> A is instructed to create a signal control plan independently from the signal control command information from the signal control device 5 or when the communication line is disconnected. In a state where communication with the control device 5 is not possible, the traffic signal controller 1A may be configured to create a signal control plan based only on control parameters stored in its own storage device or the like.

[Operation of signal controller]
Next, the operation of the signal control device 5 will be described.
FIG. 6 is a schematic diagram of functional blocks of the signal control device 5.
The signal control device 5 transmits information to and from a plurality of traffic signal controllers including the traffic signal controller 1A and other traffic signal controllers (not shown) by a transmission unit 501 and a reception unit 511 through a communication line. Sending and receiving.

The traffic condition acquisition means 531 collects sensor information transmitted from one or more vehicle sensors (not shown) installed on the road and accumulates them in the traffic information database 532. Based on these sensor information, the traffic situation on the road where the vehicle sensor is installed and the surrounding area is grasped. In this case, the traffic condition is grasped at a cycle such as every 5 minutes or every traffic light cycle time. In grasping the traffic situation, indicators such as traffic volume, occupation time, average travel speed, queue length of a group of vehicles on each road are used.
For example, the traffic ratio on the main road side and the secondary road side fluctuated significantly at one intersection, and the inflow traffic exceeded the saturation traffic flow rate at the intersection and reached saturation at another intersection. Know the situation.

Next, the plan creation time instruction means 551 gives an instruction to each traffic signal controller about the signal control plan creation time of each intersection based on the traffic situation and time zone.
For example, if the traffic situation was congested and the conventional method was instructed to create a signal control plan for the next cycle immediately before the start of the next cycle, the traffic situation shifted to a quiet state. If there is, it is instructed to change the plan creation time to the time immediately before this cycle or the time when approximately half of this cycle is executed. By doing so, the determinism of the signal information is increased, and it becomes possible to execute signal control that contributes to prevention of traffic accidents.

In this case, as the instruction method, for example, when the plan creation period coincides with the period of the current cycle, the elapsed time after the start of the current cycle (for example, 30 seconds) may be specified. And the number of the current cycle (for example, the sixth floor if the cycle consists of a total of 10 floors) and the present (for example, the second present if the cycle is composed of 3 presents), etc. You may specify with. The traffic signal controller that has received the instruction may determine the designated floor number, the start time or end time of the display, or any time when the floor or display is being executed as the plan creation time.
Also, for example, three points of time, that is, a plan creation period start point K1, a substantially intermediate point K2 of the plan creation period, and an end point K3 of the plan creation period are determined in advance as an identification code, and the signal control device 5 By instructing any of K1 to K3, the traffic signal controller 1A may set the time indicated by the instructed identification code as the plan creation time.
The instruction may be sent only when it is desired to change the plan creation time point, or may be sent for each cycle regardless of whether or not there is a change.

Then, the signal control command creating means 521 determines a blue time, a cycle length, an offset, etc. to be assigned to the display of each intersection based on the traffic situation, and creates the signal control command information including these. In determining the blue hour allocation, for example, a method of calculating the saturation and the load factor for each inflow path at the intersection and determining the allocation in accordance with the ratio is considered. And the instruction | indication regarding operation | movement of each traffic signal controller is given by transmitting the produced said signal control command information to each traffic signal controller at any time.
Each traffic signal controller that has received the signal control command information determines a signal control plan based on the signal control command information received last at the time of plan creation.

In this case, for example, if the traffic signal controller 1A instructs to create a signal control plan for the next cycle when the cycle is executed about half, the next cycle is executed when the half is executed. It is preferable to generate and transmit signal control command information corresponding to the traffic situation after predicting the traffic situation at a future time point to be executed. By doing so, it becomes possible to create appropriate signal control command information according to the traffic situation at the time when the traffic light is actually controlled.
If the traffic situation prediction is, for example, the traffic volume flowing into an intersection, the number of vehicles flowing into the intersection in the near future is determined from the measurement result of the vehicle detector installed upstream from the intersection. An estimation method can be used. Search past data similar to the current traffic situation using the past statistical data stored, and predict traffic jam length, travel time, etc. in consideration of conditions such as time zone and day type. You can also.

  Further, the command transmission time point determination means 541 determines the time point when the traffic signal controller 1A is approaching the timing at which the traffic signal controller 1A is expected to create the signal control plan as the transmission time point of the signal control command information. It is preferable to transmit. Further, in this case, it is preferable that the signal control command creating means 521 creates signal control command information based on the latest traffic situation obtained immediately before the transmission time point and transmits the signal control command information. This is because the traffic conditions change from moment to moment, so that it is easier for the traffic signal controller 1A to adopt the signal control command information created based on the latest traffic conditions as much as possible.

  In addition, when the traffic signal controller 1A transmits notification information related to the creation timing of the signal control plan to the signal control device 5, the signal control command information is traffic signal controlled immediately before the creation timing. What is necessary is just to transmit with respect to the apparatus 1A. According to such a method, it is not necessary to predict the timing of creating a signal control plan for each traffic signal controller, and even if the timing of creation differs for each traffic signal controller, each traffic signal control The signal control command information can be transmitted at an appropriate timing according to the machine.

Furthermore, when the notification information includes information related to the signal control plan of the current cycle that has already been determined at the time of the notification, information on the signal control plan of the current cycle is included in the prediction of the traffic situation. It is preferable to utilize.
However, the reason that the signal lamp is actually controlled according to the signal control plan of the next cycle created by the traffic signal controller 1A is shortly after the end of this cycle being executed by the traffic signal controller 1A.
Specifically, for example, the execution start time of the next cycle is a future point in time for the remaining period until the end of this cycle, so by utilizing the information of this cycle, the start point of the next cycle is accurately determined. You will be able to grasp. In addition, it is possible to accurately estimate the amount of traffic that can be made within the execution time of the cycle according to the allocation of the blue hours of the cycle, so the traffic situation at the time of execution of the next cycle can be predicted more accurately. It becomes.

  For example, the following method is conceivable as the details of the processing when the plan creation time instruction means 551 of the signal control device 5 instructs the plan creation time.

First, the average traveling speed of the vehicle on the road R (the actual value obtained from the speed sensor or the like) may be determined from the traffic volume and the occupied time measured by the vehicle detector installed on the road R or upstream of the road R. And an estimated value or a predicted value may be calculated), and a comparison is made as to whether or not the average traveling speed of the route flowing into the intersection A of the road R exceeds a predetermined first threshold (for example, 60 km / h).
Here, if the first threshold value is exceeded, it is determined that the traffic flow is smooth and the traffic situation is “quiet”. When the traffic situation is quiet, the field of view of the driver of each vehicle is widened, and the speed is likely to be exceeded. When the traffic light ahead is blue, the number of cases where the accelerator is depressed unintentionally increases. In this case, the plan creation time instruction means 551 determines that there is a benefit in operating the system so that the determinism of the signal information is increased and the safe driving support operation functions effectively, and the first or first half of the plan creation period is determined. Is determined as the plan creation time. For example, the first floor or the instruction information storing the identification code K1 is created and transmitted to the traffic signal controller 1A.

If the first threshold value is not exceeded, it is determined whether or not a second threshold value (for example, 40 km / h) smaller than the first threshold value is exceeded. If the second threshold value is exceeded, it is determined that the traffic situation is “near saturated”. When the traffic situation is near saturation, the vehicle's running speed is not high speed but it is not non-noro driving, so there is a situation where traffic accidents occur to some extent, and traffic congestion may occur if the real-time performance of signal control is significantly reduced There is also. In this case, the plan creation time instruction means 551 determines that the system should be operated so that both the determinism of the signal information and the real-time property of the signal control can be secured to some extent. Determine as the plan creation time. For example, the 6th floor (in the case of a total of 10 floors, etc.), the instruction information storing the identification code K2, etc. are created and transmitted to the traffic signal controller 1A.
If the average speed is smaller than the second threshold, it is determined that the state is “supersaturated”, and it is determined that a traffic jam has occurred. In this case, since the probability that a serious traffic accident will occur is small and the traffic congestion should be resolved as soon as possible, the last or second half of the plan creation period is determined as the plan creation time point. For example, the 10th floor (in the case of a total of 10 floors, etc.), the instruction information storing the identification code K3, etc. are created and transmitted to the traffic signal controller 1A.

In determining the traffic situation, for example, if it is possible to measure the traffic jam length in addition to the traveling speed, the traffic jam length may be used as a reference, or a number of traffic indicators such as traffic volume and speed can be used. You may make it classify | categorize into a pattern and meticulously instruct | indicate. Moreover, the method of switching simply according to a time slot | zone may be sufficient, and you may use both a traffic condition and a time slot | zone as a reference | standard of judgment. For example, if it is known that traffic accidents are particularly likely to occur during evening twilight hours or nighttime hours, instructions that prioritize signal information determinism regardless of traffic conditions only during these times May be sent.
For intersections that are considered to have a large impact on surrounding traffic conditions, it is possible to use a method that gives priority to real-time signal control except at night, and operates the traffic system. The person in charge of operation may decide the operation method in policy.

In addition, a function corresponding to the plan creation time instruction means 551 is installed in each traffic signal controller, and each traffic signal controller uses the traffic situation and time zone around the installed point as a criterion for judgment in the signal control plan. The creation time may be determined.
Further, for example, for a plurality of traffic signal controllers installed geographically in the vicinity or a plurality of traffic signal controllers operated with the same cycle length, the plan creation time points may be unified. In this case, the signal control device 5 may group the traffic signal controllers to be controlled and determine the plan creation time uniformly for each group, or exchange information in the traffic signal control period. If possible, a method may be used in which a core traffic signal controller notifies other traffic signal controllers of their plan creation time, and other traffic signal controllers follow this. .

[Basic operation of in-vehicle equipment]
Hereinafter, the basic operation of the in-vehicle device 6 will be described in detail.
FIG. 7 is a schematic diagram of the functional blocks of the in-vehicle device 6 and the vehicle C in which the in-vehicle device 6 is mounted.

In addition to the in-vehicle device 6, the vehicle C is provided with an engine for advancing the vehicle C and a brake for braking. The engine and the brake can be controlled by a driver operating an accelerator pedal, a brake pedal, and the like, but can also be automatically controlled based on an instruction from the in-vehicle device 6 or the like.
In addition, the vehicle C includes a display (head-up display, a display device for a car navigation device, etc.) for notifying a passenger of various types of information based on information from the in-vehicle device 6 by means of images, sounds, etc. A speaker is provided.

The signal information etc. acquiring means 601 receives and acquires the signal information, road shape information, etc. sent from the communication antenna 1Aa by a predetermined communication method via a receiving antenna (not shown) mounted on the vehicle C. To do.
In this case, the communication method used for road-to-vehicle communication may use any frequency band such as a long wave band or a short wave band, the modulation method may be any method such as OFDM or CDMA, and the procedure is also CSMA. Any method such as / CA may be used.
When signal information or the like is transmitted from different transmitters, a receiving unit may be provided for each piece of information.

Next, the safe driving support control based on the acquired signal information and the like will be described in detail. The safe driving support control refers to predicting the display lamp color of the signal lamp 2Aa when the stop line P is reached and supporting the driver's safe driving according to the prediction result.
Specifically, the notification information creation means 611 creates voice information for the passenger and notifies it through a speaker, or creates image information and notifies it through a display. Further, the speed control means 621 controls the engine and the brake to automatically brake the vehicle C and assist the driver's driving.

  First, the current traveling speed of the vehicle C is acquired by speed acquisition means (not shown) such as a wheel speed sensor, and the distance to the stop line P is acquired based on the received road shape information and the like. And the required time to the stop line P at the time of drive | working with the acquired said travel speed is acquired.

And the indicator lamp color of 2 Aa of signal lamps after progress of the said required time is estimated.
For example, if the required time is calculated as 30 seconds, if the signal information shown in FIG. 2 is received, the traffic light changes to a red light after 30 seconds, so the vehicle C stops before the stop line P. Judgment should be made.

In this case, the notification information creating means 611 creates sound information such as “the signal will soon turn red” or “should stop before the stop line” as notification information to the driver, and notifies the information through a speaker or the like. Furthermore, these are displayed as character information on a head-up display, or a character or design that prompts the display of the car navigation device to stop is displayed.
Further, the speed control means 621 sends a control signal to the accelerator and brake to assist the driver's driving by preventing the vehicle C from accelerating any more or decelerating. In this case, it may be displayed separately on a display device or the like that the vehicle is automatically decelerating, or may be notified to the driver by voice.
In addition, when the driver entrusts the driver to fully automatic operation, the brake and the accelerator may be continuously controlled so that the driver stops safely and smoothly before the stop line P.

  If it is determined that a green signal is displayed when the stop line P is reached, the notification information creating unit 611 does not have to create the notification information, and “passes the intersection safely as it is. You may make it produce | generate and alert | report the audio | voice information etc. which should be able to drive calmly. Further, the speed control unit 621 does not need to perform an operation such as brake assist.

  As described above, according to the present invention, the time point for creating a signal control plan can be changed for each cycle, so that the operation of the system can be freely switched according to the time zone and traffic conditions. . This makes it possible to implement traffic signal control in view of the benefits of both real-time signal control and determinism of signal information.

  In addition, the traffic signal controller, the signal control device, and the like in the present invention may be realized by a single casing or may be realized by a combination of a plurality of casings. Each of these may be realized by one computer or may be realized by combining a plurality of computers.

  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.

It is a schematic diagram which shows the outline | summary of apparatus arrangement | positioning of the traffic system which concerns on this invention. (A) is a figure which shows an example of the format of the signal information which concerns on this invention, (b) is a figure which shows an example of signal information. It is a figure which shows an example of the functional block structure of 1 A of traffic signal controllers. It is a figure which shows the determination procedure of the preparation timing of a signal control plan, etc. (A) is a figure which shows an example of the signal control plan stored in the present signal control plan table 102, (b) is a figure which shows an example of the signal control plan stored in the next signal control plan table 103. 3 is a diagram illustrating an example of a functional block configuration of a signal control device 5. FIG. It is a figure which shows an example of the functional block structure of the vehicle equipment.

Explanation of symbols

1A Traffic signal controller 1Aa Communication antenna 2Aa Signal lamp 4 Router 5 Signal controller 6 On-board unit 7 Transmitter 101 Signal control plan creation means 102 Current signal control plan table 103 Next signal control plan table 111 Signal lamp control means 121 Signal information creation Means 131 Central device information reception means 141 Plan creation time determination means 151 Plan creation time notification means 501 Transmission means 511 Reception means 521 Signal control command creation means 531 Traffic condition acquisition means 532 Traffic information database 541 Command transmission time decision means 551 Plan creation time Instruction means 601 Signal information etc. acquisition means 611 Notification information creation means 621 Speed control means

Claims (12)

Signal control for creating a signal control plan for one cycle at any point in the plan creation period corresponding to a period from the start point of the immediately preceding one cycle immediately before the one cycle to the end point of the immediately preceding one cycle Plan creation means,
In accordance with the created signal control plan, signal lamp control means for switching each signal lamp color in the one cycle,
A traffic signal controller having signal information creating means for creating signal information relating to the display of the current and future signal lamps based on the created signal control plan;
A transmission system including transmission means for transmitting the signal information to a predetermined area on the road,
The traffic control system is characterized in that the signal control plan creation means determines at which point in the plan creation period to create a signal control plan of one cycle before the start of the plan creation period. The signal control plan creation means includes:
It is configured to select and determine the signal control plan creation time from a plurality of candidates,
The traffic system according to claim 1, wherein the plurality of candidates include at least three points of time: a start point of the plan creation period, a substantially intermediate point of the period, and an end point of the period. The transportation system is
The apparatus further comprises a signal control device having signal control command creating means for creating signal control command information used for creating the signal control plan, and command transmitting means for sending the signal control command information to the traffic signal controller. ,
The signal control device includes:
A plan creation time instruction means for giving an instruction as to when to create a signal control plan at which point in the plan creation period for the traffic signal controller,
The traffic system according to claim 1 or 2, wherein the traffic signal controller determines a signal control plan creation time point according to the instruction. The transportation system is
A traffic condition acquisition means for acquiring a traffic condition around an installation point of the traffic signal controller;
The traffic system according to claim 3, wherein the plan creation time instruction means gives an instruction according to the acquired traffic situation. The traffic condition acquisition means acquires a vehicle traveling speed around an installation point of the traffic signal controller,
5. The traffic system according to claim 4, wherein the plan creation time instruction means gives an instruction according to the vehicle traveling speed. The plan creation time instruction means includes:
It is configured to give instructions every cycle,
If the vehicle traveling speed has improved compared to the vehicle traveling speed when the previous instruction was given, give an instruction to make the signal control plan creation time earlier than the previous instruction. The traffic system according to claim 5. The traffic signal controller is
The said signal control plan preparation means is further provided with the notification means which produces the notification information regarding the time of producing a signal control plan, and notifies to the said signal control apparatus, The one of Claim 3 thru | or 6 characterized by the above-mentioned. Transportation system. The signal control device includes:
8. The traffic system according to claim 7, wherein a transmission time point of the signal control command information is determined based on the notification information. The signal control device includes:
Traffic condition prediction means for predicting a traffic condition at a future time point when the signal light color is actually controlled according to a signal control plan created using the signal control command information;
The traffic system according to any one of claims 3 to 8, wherein the signal control command creating means creates signal control command information corresponding to the predicted traffic situation.   A traffic signal controller used in the traffic system according to any one of claims 1 to 9. Signal control plan creation for creating a signal control plan for one cycle at any point in the plan creation period from the time immediately before the start of the previous cycle immediately before the previous cycle to the end of the previous cycle. Means,
In accordance with the created signal control plan, signal lamp control means for switching each signal lamp color in the one cycle,
Based on the created signal control plan, signal information creating means for creating signal information related to current and future display of the signal lamp, and
Output means for outputting the signal information to the outside;
Having a traffic condition acquisition means for acquiring the traffic condition;
The signal control plan creation means determines at which point in the plan creation period to create a one-cycle signal control plan according to the acquired traffic situation at a time immediately before the start of the plan creation period. A traffic signal controller characterized by being configured. The signal control plan creation means includes:
It is configured to select and determine the signal control plan creation time from a plurality of predetermined candidates,
The traffic signal controller according to claim 11, wherein the plurality of candidates include at least two time points of a start time of the plan creation period and an end time of the period.

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