JP2011060019A - Traffic signal control device and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform traffic signal control not to be disadvantageous for a user of a navigation system, considering a future traffic volume which can be caused by route search. <P>SOLUTION: The traffic signal control device 4 for generating a signal control instruction S1 for controlling the switching time of signal lamp color of a traffic signal 1 obtains a route of a vehicle 5 having a result of route search, and calculates a partial traffic volume for each time zone with respect to the vehicle 5 running to an intersection Ci included in the route. The device 4 also calculates a prediction traffic volume for each time zone with respect to the intersection Ci that is a control object by use of the partial traffic volume, and generates the signal control instruction S1 based on the prediction traffic volume. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an improvement in signal control for controlling the timing of switching the signal light color of a traffic signal based on a predicted traffic volume flowing into an intersection.
In more detail, in addition to roadside measurement information from roadside sensors such as vehicle detectors, traffic traffic fluctuations at intersections are dynamically predicted from the route obtained as a result of route search, and the signal light color of traffic lights is improved. TECHNICAL FIELD The present invention relates to a traffic signal control device that performs control and a computer program for realizing traffic signal control by this device.

The conventional signal control method for traffic signals by system control and wide area control can be broadly classified from the viewpoint of setting method of signal control parameters (split, cycle length, offset, etc.). There are two types: periodic control and traffic sensitive control that sets signal control parameters according to traffic conditions.
Among these, the latter traffic sensitive control is classified into terminal sensitive control performed for each traffic signal controller of the terminal and central sensitive control that changes signal control parameters for a plurality of intersections that are route system controlled or surface controlled. The

Since the above-mentioned central sensitive control can perform advanced system control and wide area control (surface control) corresponding to fluctuations in traffic flow, roads with high temporal traffic fluctuations, heavy traffic volumes, and high traffic processing efficiency are required. The program selection control or the program formation control is adopted.
The program selection control is a method of selecting one optimal program for a traffic state at that time from a plurality of preset programs based on vehicle sensor information. The program formation control is a method of determining signal control parameters and signal display switching timing online based on vehicle sensor information, instead of setting a finite number of parameter values in advance.

In the central sensitive control performed by the traffic control center, program selection control is generally adopted, but this has the following disadvantages.
(1) A great deal of labor is required to design parameters.
(2) Redesign is required when the traffic situation changes greatly due to aging.
(3) The evaluation index (weighted sum of traffic volume and occupation rate) is empirical and ambiguous.
(4) The cycle length tends to be long in order to provide a margin, and it is easy for wasteful green time to occur or for the pedestrian waiting time to increase.

  Therefore, in order to solve the above disadvantages, program formation control is performed in which the central device of the traffic control center automatically updates the signal control parameters according to traffic conditions. This control method is MODERATE (Management by Origin- DEstination Related Adaptation for Traffic Optimization) control (see Non-Patent Document 1).

On the other hand, in addition to the above MODERATO control, a control method called UTMS (Universal Traffic Management Systems) that further improves real-time performance by optimizing the blue time using future prediction information for signal control at some intersections May be adopted. The features of this UTMS control are as follows (see Non-Patent Document 2).
(1) Predicting future one-cycle traffic demand from now (2) Realization of real-time control based on direct evaluation of vehicle time delay (3) Distributed control decision-making: hybrid type or adjacent intersection in conjunction with central control Autonomous control mode that works with emphasis can be selected

In such UTMS control, an arrival profile that is time-series data of predicted traffic volume at which a vehicle arrives at an intersection stop line is estimated every predetermined time, and a simulation calculation is performed based on this arrival profile and other signal control information. Execute.
Specifically, the above simulation calculation calculates a delay time (signal stop waiting time) that is the fluctuation state of the number of queues at the entire intersection, and searches for the blue end timing at which the evaluation value based on this delay time is the smallest. The optimal blue end timing is determined (see Non-Patent Document 2).

"Revised Traffic Signal Guide" Editorial and publication Traffic Engineering Research Group (16-18, 83-87) "Development and Demonstration Experiment of Next Generation Signal Control System" SEI Technical Review No. 166, March 2004, pages 51-55

The number of queues, which is a traffic index necessary for performing MODERATO control and UTMS control, is usually based on the amount of traffic flowing into the controlled intersection detected by a roadside sensor such as a vehicle detector installed on the road. Is calculated by estimating the queue length and dividing this by the average vehicle head distance.
However, the traffic index obtained from the inflow traffic detected by the roadside sensor such as a vehicle detector does not reflect the traffic situation of the road where the roadside sensor is not installed. Even if it goes, there may be cases where the traffic signal control does not necessarily match the actual situation.

For example, if the above UTMS control is performed when a specific road section in the control area is congested, the blue time in the traveling direction of the congested section becomes longer in order to eliminate the congested section. The signal is controlled so that the blue time is shortened.
At the same time, however, if a lot of vehicles are guided along the route of the intersection to avoid the traffic jam section as a result of the route search by the navigation system, a new traffic jam occurs in the intersection section this time. There is a possibility that the execution of the UTMS control may encourage traffic congestion in the intersection section.

As described above, the traffic signal control executed based on the roadside measurement information may contradict the trend of the vehicle traveling according to the result of the route search. In this case, for the user of the navigation system, the traffic signal control is On the contrary, it becomes annoying.
In view of such circumstances, the present invention has an object to provide a traffic signal control device and the like that can perform traffic signal control that is not disadvantageous for a user of a navigation system in consideration of future traffic volume that may occur due to route search. And

  (1) The traffic signal control device of the present invention is a traffic signal control device that generates a signal control command for controlling the timing of switching the signal light color of a traffic signal, and acquires a vehicle route having a route search result. The first calculation means for calculating the partial traffic volume for each time zone for the vehicle flowing into the intersection included in the route, and the intersection to be controlled using the partial traffic volume. And a generating means for generating the signal control command based on the predicted traffic volume. The second calculating means for calculating the predicted traffic volume for each time zone.

According to the traffic signal control apparatus of the present invention, the first calculation means calculates the partial traffic volume for each time zone for the vehicle flowing into the intersection included in the route of the vehicle having the route search result. The second calculating means uses the partial traffic volume to calculate the predicted traffic volume for each time zone for the intersection to be controlled, so that the predicted traffic volume is intended to travel according to the route search result. The traffic volume of the vehicle is considered. Note that the “route” in this case means a route obtained by route search, and therefore, the vehicle is considered highly likely to travel along the route.
And since the said production | generation means produces | generates a signal control instruction | command based on the predicted traffic volume which considered the traffic volume which can generate | occur | produce by route search, the traffic signal control which does not become disadvantageous for the user of a navigation system can be performed.

(2) Roads that flow into intersections include roads that do not have roadside sensors that can detect the number of passing vehicles (hereinafter sometimes referred to as “sensorless roads”) and roads that have roadside sensors (hereinafter referred to as “ There are cases where it is referred to as “a road with a sensor.”), But it is preferable to individually calculate the predicted traffic volume corresponding to these road types.
The reason for this is that the past traffic volume based on roadside measurement information is unknown for roads without sensors, so it is not necessary to reflect this past traffic volume in the predicted traffic volume. This is because the traffic volume is known and the past traffic volume should be reflected in the predicted traffic volume.

  Specifically, the second calculation means is based on a value obtained by multiplying the partial traffic volume of the road by a predetermined ratio for a road without a roadside sensor for detecting roadside measurement information including the number of passing vehicles. The total traffic volume may be adopted as the predicted traffic volume.

  (3) Further, the second calculation means, for a road with a roadside sensor capable of detecting the number of passing vehicles, calculates the past traffic volume based on the roadside measurement information and the partial traffic volume of the road. A traffic volume obtained from the total traffic volume based on a value multiplied by a predetermined ratio may be adopted as the predicted traffic volume.

(4) On the other hand, as a method for converting the partial traffic into the total traffic, for example, the following method can be considered. That is, a roadside communication device (for example, an optical beacon) that can receive the uplink transmitted by the vehicle and detect the number of passing vehicles at the reception position is installed on the road in the control area managed by the device itself. And the second calculating means applies the ratio of the number of uplinks detected by the roadside communication device and the number of passing vehicles to the partial traffic volume to calculate the total traffic volume. Can do.
The reason is that the ratio between the number of uplinks and the number of passing traffic is considered to be approximately the same as the ratio between the partial traffic volume and the total traffic volume.

(5) In the second calculation means, the ratio of the number of vehicles capable of transmitting the route or input information necessary for the search to the outside and the registered number of all vehicles is applied to the partial traffic volume. Thus, the total traffic volume may be calculated.
The reason is that the ratio between the number of vehicles and the registered number of all vehicles is also considered to be substantially equal to the ratio between the partial traffic volume and the total traffic volume.

  (6) The computer program of the present invention is a computer program for causing a computer to execute control by the traffic signal control device of the present invention, and has the same effects as the traffic signal control device of the present invention.

  As described above, according to the present invention, since the signal control command is generated based on the predicted traffic volume in consideration of the traffic volume that can be generated by the route search, the traffic signal control that is not disadvantageous for the user of the navigation system. It can be performed.

It is a whole lineblock diagram showing an outline of a traffic signal control system. It is a road top view for showing the composition of a traffic signal. It is a functional block diagram which shows the internal structure of a central apparatus. It is a functional block diagram which shows the internal structure of a traffic signal controller. It is a functional block diagram which shows the internal structure of a vehicle-mounted apparatus. It is a flowchart of traffic signal control including calculation processing of predicted traffic. It is a road top view for showing an example of the calculation method of a mounting rate. It is a road top view for demonstrating the effect of traffic signal control. It is a road top view for demonstrating the effect of traffic signal control. It is a top view of the road intersection for showing a modification.

[Overall system configuration]
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows the overall configuration of a traffic signal control system employing the present invention. FIG. 2 is a road plan view showing the configuration of the traffic signal 1 of the system.
As shown in FIGS. 1 and 2, the traffic signal control system of the present embodiment includes a traffic signal 1, a vehicle-mounted device 2, a roadside sensor 3 including a vehicle detector, a central device 4, and a vehicle 5 equipped with the vehicle-mounted device 2. , A route search server 9, a VICS (Vehicle Information and Communication System: “VICS” is a registered trademark) center 10, an optical beacon 11, and the like.

1 and 2, among various signals or information indicated by reference numerals S <b> 1 to S <b> 5, S <b> 1 is a signal control command for controlling the signal lamp color switching timing of the traffic signal device 1 generated by the central device 4. .
S2 is VICS information generated by the VICS center 10. This VICS information S2 includes traffic jam information, link travel time, accident / malfunction vehicle / construction information, speed regulation / lane regulation information, parking location, parking / service / parking area full / empty information, etc. It is.

Further, S3 is probe information generated by the vehicle (probe vehicle) 5 on which the in-vehicle device 4 is mounted. The probe information S3 includes the position, speed, time, and the like of the traveling vehicle 5 for a predetermined time or distance. include. S4 is roadside measurement information (for example, the number of passing vehicles 5) measured by the roadside sensor 3.
S5 is route information generated by the route search server 9. The route information S5 includes a route (minimum cost) calculated so as to minimize the route cost from the departure point to the destination point in response to a search request from the user of the server 9 (such as the driver of the probe vehicle 5). Route).

In the traffic signal control system shown in FIG. 1, each traffic signal 1 is installed at each of a plurality of intersections Ci (i = 1 to 12) and connected to a router 7 via a communication line 6 such as a telephone line. .
This router 7 is connected to a central device 4 in the traffic control center, and the central device 4 constitutes a local area network (LAN) with the traffic signal controller 1a of each intersection Ci included in the control area under its control. ing.

Therefore, the central device 4 can perform bidirectional communication with each traffic signal controller 1 a, and each traffic signal 1 can also perform bidirectional communication with other traffic signals 1. The central device 4 may be installed on the road instead of the traffic control center.
Further, in FIG. 1, for simplification of illustration, only one signal lamp 1b is depicted at each intersection Ci. However, as shown in FIG. There are four signal lamps 1b for up and down.

The roadside sensor 3 is, for example, a vehicle detector that ultrasonically senses the vehicle 5 that passes underneath, a loop coil that senses the vehicle 5 by inductance change, or an image of a camera to perform traffic processing and vehicle speed. It consists of an image sensor to be measured, and is installed on some roads in the control area for the purpose of measuring the number of vehicles flowing into the intersection Ci and the vehicle speed.
This roadside sensor 3 is installed on the upstream side of the corresponding intersection Ci, and is connected to the traffic signal controller 1a via a communication line. The roadside measurement information S4 detected by the roadside sensor 3 is relayed by the traffic signal controller 1a and transmitted to the central device 4 via the communication line 6.

As shown in FIG. 2, the optical beacon 11 includes a beacon controller 11 a attached to a post on the road side, and one or more beacon heads attached to a beam member extending from the upper end of the post to the road side ( Projector / receiver: hereinafter simply referred to as “head”) 11b.
The beacon controller 11a can perform bidirectional communication with the traffic signal controller 1a through the communication line 8. The heads 11b are provided as many as the number of lanes on the road, and are arranged immediately above the lanes. Each head 11b has a light emitting element and a light receiving element therein.

The range (communication area) on the road where communication is possible when these elements emit or receive light is set slightly upstream from directly below the head 11b. The in-vehicle device 2 (an optical communication unit 204 described later) can transmit and receive the uplink UL and the downlink DL with the head 11b while passing through the communication area.
The beacon controller 11a can include the VICS information S2 and the route information S5 received through the traffic signal controller 1a in the downlink DL transmitted to the in-vehicle device 2. The uplink UL transmitted by the in-vehicle device 2 includes probe information S3, and this probe information S3 is transferred to the route search server 9 via the traffic signal controller 1a.

Inside the head 11b of the optical beacon 11, a sensor for ultrasonically sensing the vehicle 5 passing directly below is also mounted, and the optical beacon 11 can also measure the number of vehicles passing directly below the head 11b. .
For this reason, the optical beacon 11 has not only a function as a roadside communication device that performs bidirectional communication with the vehicle 5 by transmitting and receiving the uplink UL and the downlink DL, but also a function as the roadside sensor 3 that detects the number of vehicles. The roadside measurement information S4 measured by the optical beacon 11 is also transferred to the central device 4 via the traffic signal controller 1a.

[Navigation system]
The route search server 9, the in-vehicle device 4 and the optical beacon 11 mounted on the vehicle 5 search for an optimum route from the departure point to the destination point with an external computer, and obtain the result of the route search (minimum cost route). A navigation system for notifying the vehicle 5 is configured.
This navigation system uses the vehicle 5 itself of a member (user) registered in advance as a sensor, the route search server 9 collects information from each vehicle 5, and provides information between the members to operate each other. The server 9 provides more useful traffic information to each member.

Therefore, according to this navigation system, more detailed and dynamic traffic information not included in the VICS information S2 can be provided to each member's vehicle 5 together with the normal VICS information S2.
The route search server 9 is connected to the traffic information center 10 via a dedicated communication line, and obtains the VICS information S2 from the center 10 as necessary. Further, the route search server 9 acquires the probe information S3 of the registered member vehicle 5 included in the uplink UL to the optical beacon 11 via the traffic signal controller 1a.

When the search request from a registered member (including the departure point and the destination point) is included in the uplink UL to the optical beacon 11, the route search server 9 has a route that minimizes the route cost such as travel time. (Minimum cost path) is calculated by the Dijkstra method or the like.
In this case, since not only the link travel time but also the traffic jam information is included in the VICS information S2, in the search algorithm performed by the route search server 9, a very large route cost is set for the traffic jam section. Therefore, when there is a traffic jam section, a route that avoids the section as much as possible is searched.

When the calculation for the route search is completed, the route search server 9 obtains the route information S5 including the minimum cost route from the starting point to the destination point, which is the search result, and the vehicle ID of the vehicle 5 that made the search request. The broadcast signal is transmitted to the beacon controller 11a of each optical beacon 11 through the traffic signal controller 1a.
Note that the minimum cost route includes a passage time that passes through a waypoint including an intersection on the route.

  When the beacon controller 11a detects the uplink UL from the vehicle 5 that has made the search request, the beacon controller 11a includes the route information S5 in the downlink DL and causes the head 11b to perform optical transmission. Thereby, the driver of the vehicle 5 that has made the search request can acquire the search result (optimum route) by the route search server 9.

[Central equipment]
FIG. 3 is a functional block diagram showing the internal configuration of the central device 4.
As illustrated in FIG. 3, the central device 4 includes a control unit 401, a display unit 402, a communication unit 403, a storage unit 404, and an operation unit 405.
The control unit 401 of the central device 4 includes a workstation (WS), a personal computer (PC), and the like, and collects, processes (calculates) and records various measurement information from the traffic signal controller 1a, the roadside sensor 3, and the like. Performs overall signal control and information provision. The control unit 401 is connected to the hardware units via an internal bus, and also controls the operations of these units.

The control unit 401 of the central device 4 controls the traffic signal 1 at the intersection Ci belonging to its own network with system control for adjusting a group of traffic signals on the same road, or wide area control that extends this system control to the road network. For example, the MODERATO control and the UTMS control can be performed.
The MODERATO control is a macro control of all traffic signals 1 belonging to the network. In order to cope with near-saturated traffic conditions, the traffic signal called load factor is used to cycle the optimal signal control parameters for each traffic signal 1. Automatically generated for each.

For example, in the case of split control, a load factor ratio distribution method for obtaining the maximum value of the load factor of each inflow path for each indication for each intersection Ci and distributing the split normalized by the ratio of the indicated load factor Is adopted. The load factor ρ is defined as ρ = (Q + E) / s using the inflow flow rate Q (vehicles / hour), the number of queues E (vehicles / hour), and the saturated traffic flow rate s (vehicles / hour). Is done.
On the other hand, the UTMS control micro-controls a part of traffic signals 1 belonging to the network, and predicts a change in traffic situation in advance based on information observed upstream of the intersection Ci of interest. Based on the above, the optimum blue cut-off timing is determined so as to minimize the delay time due to the signal waiting at the intersection Ci.

In such UTMS control, simulation calculation is performed based on stop line arrival profile information and signal control information at a certain intersection Ci, and the fluctuation state of the number E of queues from the present time to the future is calculated.
In the present embodiment, since the MODERATO control and the UTMS control are performed in the central device 4, the control unit 401 becomes the input information when executing these controls, and the predicted traffic volume of each intersection Ci (flows into the intersection Ci). Number of vehicles to be calculated). Details of the method for calculating the predicted traffic volume (FIG. 6) will be described later.

The communication unit 403 of the central device 4 is a communication interface connected to the LAN side via the communication line 6 and is acquired from the VICS center 10 with a signal control command S1 related to the lamp color switching timing of the signal lamp 1b every predetermined time. The VICS information S2 including the traffic jam information and the like transmitted to each traffic signal controller 1a.
The signal control command S1 is transmitted every calculation period (for example, 1.0 to 2.5 minutes) of the signal control parameter, and the VICS information S2 is transmitted every five minutes, for example.

  Further, the communication unit 403 of the central device 4 receives the roadside measurement information S4 detected by the roadside sensor 3 or the optical beacon 11 from each traffic signal controller 1a in real time (for example, in a cycle of 0.1 to 1.0 second). In addition, the route information S5 generated by the route search server 9 is also acquired from the server 9 in almost real time.

The storage unit 404 of the central device 4 includes a hard disk, a semiconductor memory, and the like, and stores a control program for performing the MODERATO control and the UTMS control, and a calculation program for predicted traffic volume and traffic index used for the control. .
The storage unit 404 also includes a signal control command S1 generated by the control unit 401, VICS information S2 acquired from the VICS center 10, roadside measurement information S4 acquired from the LAN side, and route information acquired from the route search server 9. S5 is temporarily stored.

The display unit 402 of the central device 4 is composed of a road map of a control area managed by the central device 4 and a display screen on which positions of all traffic signals 1 and optical beacons 11 on the road map are displayed. It informs traffic conditions such as traffic jams and accidents.
The operation unit 405 of the central device 4 includes an input interface such as a keyboard and a mouse. The operation unit 405 allows the central operator to perform a display switching operation on the display unit 402.

[Traffic signal]
Next, with reference to FIG.2 and FIG.4, the structure of the traffic signal 1 is demonstrated. FIG. 2 illustrates an intersection Ci where the main roads RM1 and RM2 having a large traffic volume and the slave roads RS1 and RS2 having a small traffic volume merge.
As shown in FIG. 2, the traffic signal 1 is connected to four signal lamps 1b installed on the main roads RM1 and RM2 and the secondary roads RS1 and RS2 and the signal lamp 1b via a communication line 8. And a traffic signal controller 1a.

The traffic signal controller 1a receives the signal control command S1 from the central device 4, and based on the signal control command S1, turns on / off each signal light such as blue, yellow, red and right turn arrow of each signal lamp 1b. Control blinking.
FIG. 4 is a functional block diagram showing the internal configuration of the traffic signal controller 1a.
As shown in FIG. 4, the traffic signal controller 1 a includes a control unit 101, a lamp driving unit 102, a communication unit 103, and a storage unit 104.

The control unit 101 of the traffic signal controller 1a is composed of one or a plurality of microcomputers, and a lamp drive unit 102, a communication unit 103, and a storage unit 104 are connected to the control unit 101 via an internal bus. The control unit 101 controls the operations of these hardware units.
The control unit 101 drives each signal lamp 1b according to a signal control command S1 that is an output resulting from the central device 4 performing system control or wide-area control (MODERATO control, UTMS control, etc.), and performs a predetermined operation based on the command S1. The signal lamp color of each signal lamp 1b is switched at the timing.

  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 control command S1 input from the control unit 101. Then, the AC voltage (AC 100 V) or DC voltage supplied to the signal lights of each color is turned on / off.

The communication unit 103 of the traffic signal controller 1 a is a communication interface that performs wired communication with the central device 4, the roadside sensor 3, and the optical beacon 11.
The communication unit 103 receives the signal control command S1 and the VICS information S2 from the central device 4, sends the signal control command S1 to the control unit 101 of the own device, and transfers the VICS information S2 to the beacon controller 11a. Further, the communication unit 103 receives the roadside measurement information S4 from the roadside sensor 3 and the optical beacon 11, and transfers this roadside measurement information S4 to the central device 4.

Further, when the communication unit 103 receives the probe information S3 from the beacon controller 11a, the communication unit 103 transfers the probe information S3 to the route search server 9 and receives the route information S5 from the route search server S3. S5 is transferred to the beacon controller 11a.
The storage unit 104 of the traffic signal controller 1a is composed of a hard disk, a semiconductor memory, or the like, stores a program for controlling the switching of the signal lamp color based on the signal control command S1, and received by the communication unit 103. Various information (signal control command S1, VICS information S2, etc.) is temporarily stored.

[In-vehicle device]
FIG. 5 is a functional block diagram showing the internal configuration of the in-vehicle device 2.
The in-vehicle device 2 has a road-to-vehicle communication function that performs bidirectional optical communication with the optical beacon 11 and a navigation function that guides the destination set by the passenger.
As shown in FIG. 5, the in-vehicle device 2 includes a GPS processing unit 201, a direction sensor 202, a vehicle speed acquisition unit 203, an optical communication unit 204, a storage unit 205, an operation unit 206, a display unit 207, an audio output unit 208, and a control unit. 209 etc.

The GPS processing unit 201 receives GPS signals from GPS satellites, and determines the position (latitude, longitude, and altitude) of the probe vehicle 5 based on time information, GPS satellite orbits, positioning correction information, and the like included in the GPS signals. measure.
The direction sensor 202 is constituted by an optical fiber gyro or the like, and measures the direction and angular velocity of the probe vehicle 5. The vehicle speed acquisition unit 203 acquires speed data of the probe vehicle 5 measured by a vehicle speed sensor (not shown) detecting the angular speed of the wheels.

The optical communication unit 204 of the in-vehicle device 2 transmits and receives the uplink UL and the downlink DL in the communication area of the optical beacon 11 set at a predetermined position on the road.
That is, when the probe vehicle 5 that has flowed out of a certain intersection Ci enters the communication area of the optical beacon 11, the optical communication unit 204 of the in-vehicle device 2 receives the downlink DL including the VICS information S2 and receives its own probe information S3. The included uplink UL is transmitted to the optical beacon 11. Note that when the optical beacon 11 receives the path information S5, the path information S5 is also included in the downlink DL.

The storage unit 205 of the in-vehicle device 2 includes a hard disk, a semiconductor memory, and the like, and stores various information such as VICS information S2 and path information S5 included in the downlink DL, and probe information S3 included in the uplink UL. It has a storage area.
The storage unit 205 also stores road map data. This road map data includes intersection data in which intersection IDs are associated with intersection positions. In the road map data, the link ID, the link start point / end point / interpolation point (corresponding to the point where the road bends), the link ID of the link connected to the link start point, and the link end point are connected. Link data in which the link ID of the link to be associated with the link cost used for specifying the optimum route is also included.

For example, the number of link costs is the same as the number of links and links connected to the end point, and after entering the start point of the link, the end point of the link is exited, and the start point of the next link to be connected is entered. The time required to do is set.
That is, the link cost includes the cost (time) required to travel from the start point to the end point of the link and the cost (time) required to travel from the end point of the link to the start point of the next link, that is, the intersection. The cost required to pass is included.

The operation unit 206 of the in-vehicle device 2 includes a touch panel, buttons, and the like, and a passenger of the vehicle 5 including a driver can set a destination.
The display unit 207 of the in-vehicle device 2 includes a monitor device (not shown) attached to the dashboard portion of the vehicle 5, and displays image data created by the control unit 209 in the sensitivity request process described later to the passenger. The audio output unit 208 outputs the audio data created by the control unit 209 from a speaker (not shown).

The control unit 209 of the in-vehicle device 2 includes one or a plurality of microcomputers, and includes a GPS processing unit 201, an orientation sensor 202, a vehicle speed acquisition unit 203, an optical communication unit 204, a storage unit 205, an operation unit 206, a display unit 207, Each process in the audio output unit 208 is controlled.
Further, the control unit 209 of the in-vehicle device 2 performs map matching on the position measured by the GPS processing unit 201, the azimuth and angular velocity measured by the azimuth sensor 202, and the speed acquired by the vehicle speed acquisition unit 203 based on road map data. By performing the processing, it is possible to calculate the position, direction, speed, and the like of the vehicle 5 on the link of the road map data.

Further, the control unit 209 of the in-vehicle device 2 generates probe information S3 obtained by collecting travel data including a position, a direction, a speed, and the like generated during the travel of the vehicle 5 at a predetermined time interval or distance interval. S3 is stored in the storage unit 205.
In this embodiment, since the optical beacon 11 is used as a means for transmitting the probe information S3 to the infrastructure side, the control unit 209 of the in-vehicle device 2 causes the optical beacon 11 to pass next to the optical beacon 11. Probe information S3 is generated by collecting traveling data generated during traveling on the route between the two.

[Traffic signal control by central equipment]
FIG. 6 is a flowchart of traffic signal control including a calculation process of predicted traffic, which is executed by the control unit 401 of the central device 4. Hereinafter, a method for calculating the predicted traffic volume for each intersection Ci will be described with reference to FIG.
As shown in FIG. 6, the control unit 401 of the central device 4 first sends the route information S5 generated by the route search server 9 and obtained as a result of route calculation for the user of the server 9 to the communication unit 403. (Step ST1).

As described above, the route information S5 includes a route cost from a departure point to a destination point in response to a search request from a user of a navigation system using the route search server 9 (for example, a driver of the probe vehicle 5). A route calculated so as to be minimized (minimum cost route) is included.
In addition, the minimum cost route includes a passage time that passes through a transit point including an intersection in the middle of the route.

Therefore, the control unit 401 of the central device 4 predicts the passing time when the vehicle 5 passes through the intersection (target intersection) Ci to be controlled by the traffic signal control based on the passing time included in the minimum cost route of the route information S5. And the number of vehicles 5 flowing into the target intersection Ci at the predicted passage time is updated (step ST2).
The control unit 401 executes the update process of the number of inflows (step ST2) for all target intersections Ci and all the route calculation results (route information S5) acquired from the route search server 9 (step ST3). And ST4).

Traffic for each time zone that flows into the target intersection Ci for the vehicle 5 that uses the result of the route search by the route search server 9 among the vehicles 5 equipped with the in-vehicle device 2 by the update process up to step ST4. The amount (hereinafter referred to as “partial traffic”) is calculated.
Then, the control unit 401 of the central device 4 calculates the predicted traffic volume for all the vehicles for the target intersection Ci based on the partial traffic volume and the roadside measurement information S4 ahead of the target intersection Ci (step). ST5).

[Estimated traffic volume estimation method (step ST5)]
Specifically, the control unit 401 of the central device 4 divides the road into the road without the roadside sensor 3 (the road without the sensor) and the road with the roadside sensor 3 (the road with the sensor), and determines the predetermined for each of these roads. The predicted traffic volume for each time zone (for example, 1 hour) is calculated according to the following equations (1) and (2).

(1) In the case of a road without a sensor Predicted traffic volume = Partial traffic volume x (1 / Installation rate) x a
(2) In the case of a road with a sensor Predicted traffic volume = Traffic volume in the same time zone one day before based on roadside measurement information S4 × (α / (α + β))
+ Partial traffic volume x (1 / Installation rate) x a x (β / (α + β))

In the above formulas (1) and (2), the “mounting rate” means the number of vehicles in which the probe information S3 is uplinked to the optical beacon 11 (the number of uplinks) and the number of vehicles counted by the same optical beacon 11. It is the value divided by (number of passing optical beacons 11).
Further, a is an adjustment coefficient that is appropriately determined within a range of 0 <a <1. Furthermore, α and β are weighting factors in the case of taking a weighted average of past traffic volume and future partial traffic volume in the case of a road with sensors, including the case where α = 1 and β = 0.

As shown in the above formulas (1) and (2), the control unit 401 according to the present embodiment calculates the predicted traffic volume by dividing the partial traffic volume generated by the route search result by the loading rate. The actual traffic volume (total traffic volume) that can occur is converted.
The reason for this is that the ratio between the number of uplinks and the number of passing vehicles (the reciprocal of the loading rate) is the ratio between the number of vehicles 5 that can use the result of the route search and the number of all vehicles including the vehicle. This is because it is considered that the ratio of the partial traffic volume and the total traffic volume of the road is almost the same.

In addition, in the case of the above formula (1), the reason why the past traffic volume based on the roadside measurement information S4 is not added is that the past traffic volume is unknown in the case of a road without a sensor. This is because it is not necessary to reflect the estimated traffic volume.
Conversely, the reason for adding the past traffic volume based on the roadside measurement information S4 in the above formula (2) is that the past traffic volume is known on the road with the sensor, so the past traffic volume is estimated traffic. This is because it should be reflected in the quantity.

[Installation rate calculation method]
FIG. 7 is a road plan view for illustrating an example of a method for calculating the mounting rate.
In FIG. 7, a solid line indicates a road where the optical beacon 11 is installed, and a broken line indicates a road where the optical beacon 11 is not installed.
The control unit 401 of the central device 4 collects the number of uplinks and the number of passages every predetermined time for each of the optical beacons 11 in a predetermined area such as a prefecture unit or a municipal unit. The average value obtained from each data is used as a loading rate when the predicted traffic volume of the intersection Ci included in the predetermined area is obtained.

But the average calculation method for calculating | requiring the mounting rate in a predetermined area may be either of following (1) and (2). In this case, the number of uplinks in each road link is ai (i = 1 to n), and the number of passing vehicles is bi (i = 1 to n).
(1) Mounting rate of a predetermined area = (Σai) / (Σbi)
(2) Mounting ratio of predetermined area = {Σ (ai / bi)} / n

Returning to FIG. 6, when the predicted traffic volume for each time zone for the target intersection Ci is obtained as described above, the control unit 401 of the central device 4 performs the MODERATO control and the UTMS control using the predicted traffic volume as input information. This generates a signal control command S1 for the target intersection Ci (step ST6).
Thereafter, the control unit 401 transmits the generated signal control command S1 to the traffic signal controller 1a at the target intersection Ci (step ST7).

[Effects of traffic signal control]
FIGS. 8 and 9 are road plan views for explaining the effect of traffic signal control by the central device 4.
In the example illustrated in FIG. 8, it is assumed that the vehicle 5 is a registered member's vehicle of the route search server 9 and obtains a route as a result of the route search from the server 9.
In addition, it is assumed that the vehicle 5 is traveling upward in the figure toward the intersection C8, and traffic congestion has occurred in a section below the intersection C5 in the figure. Furthermore, since the intersection C6 is on an elevated road, the vehicle 5 flowing into the intersection C6 in the direction of arrow A can only go to the intersection C5, and there is no roadside sensor 3 in the section from the intersection C1 to the intersection C5. .

In this case, if the control unit 401 of the central device 4 performs UTMS control based on the predicted traffic volume obtained only from the roadside measurement information S4, in order to eliminate the traffic jam, the traveling direction of the traffic jam section (intersection) The traffic light 1 at the intersection C5 is controlled so that the blue time in the direction of passing through C5) becomes longer and the blue time in the intersection section of the traffic jam section (the direction passing through the intersection C5 to the left) becomes shorter. become.
On the other hand, at the same time, the route search server 9 searches for the minimum cost route based on the link travel time and traffic jam information included in the VICS information S2, and notifies the vehicle 5 of the result.

Therefore, the route search result by the server 9 is, for example, a route that bypasses the traffic jam section and exits the intersection C5 to the left as shown by a virtual line in FIG. 8 (C8 → C4 → C2 → C1 → C5). If a large number of vehicles 5 that have acquired such a route are generated, a new traffic jam may occur in the intersection section from the intersection C1 to the intersection C5.
However, since the roadside sensor 3 is not provided in the section from the intersection C1 to the intersection C5, even if a new traffic jam occurs in this section, the signal control based only on the roadside measurement information S4 causes the lateral direction of the intersection C5. A green light is not preferentially assigned.

In the example shown in FIG. 9, it is assumed that the vehicle 5 is going to travel a route toward the tourist destination via the intersection C9 according to the result of the route search by the route search server 9. In the section, it is assumed that traffic jam occurs due to the vehicle 5 that regularly uses this section for commuting purposes. Furthermore, it is assumed that there is no roadside sensor 3 in the intersection section passing through the intersection C9 in the horizontal direction.
Even in this case, if the control unit 401 of the central device 4 performs the UTMS control based on the predicted traffic volume obtained only from the roadside measurement information S4, in order to eliminate the traffic jam, the traveling direction of the traffic jam section The traffic light 1 at the intersection C9 is controlled so that the blue time in the direction passing through the intersection C9 becomes longer and the blue time in the intersection section of the traffic jam section (direction passing through the intersection C9 to the left) becomes shorter. Will be.

Then, as shown by the phantom line in FIG. 9, when many vehicles 5 that have acquired the route to the tourist spot from the route search server 9 are generated, a new traffic jam occurs in the intersection section that passes through the intersection C9 to the left. There is a fear.
However, since the roadside sensor 3 is not provided in the intersection section of the intersection C9, signal control based only on the roadside measurement information S4 has priority in the lateral direction of the intersection C9 even if a new traffic jam occurs in the intersection section. Is not assigned a green light.
Thus, the traffic signal control executed based on the roadside measurement information S4 may contradict the trend of the vehicle 5 traveling according to the result of the route search. In this case, for the user of the route search server 9, The traffic signal control by the central device 4 becomes inconvenient.

On the other hand, according to the central device 4 of the present embodiment, the partial traffic for each time zone for the vehicle 5 that flows into the intersections C5 and C9 included in the route obtained as a result of the search by the route search server 9. Since the traffic volume is calculated and the predicted traffic volume for each time zone for the intersections C5 and C9 to be controlled is calculated using the partial traffic volume, the predicted traffic volume is intended to travel according to the route search result. The traffic volume of the vehicle 5 is taken into account.
In the central device 4 of the present embodiment, the signal control command S1 is generated based on the predicted traffic volume taking into account the traffic volume that can be generated by the route search, so that traffic that does not disadvantage the user of the route search server 9 Signal control can be performed.

[Modification]
FIG. 10 is a plan view of a road intersection for illustrating a modification of the present invention.
This modified example is different from the above embodiment (FIGS. 1 to 7) in the following (1) and (2). Other device configurations and calculation of predicted traffic volume performed by the central device 4 The method and the method for generating the signal control command S1 are the same as those in the above embodiment.

  (1) The in-vehicle device 2 includes a mobile terminal device 204A including a mobile phone, a PHS terminal, a PDA terminal, and the like as the communication unit 204, and the stored probe information S3 is stored in the mobile phone network or the like using the terminal device 204A. To an external network (not shown). The route search server 9 acquires the probe information S3 transmitted to the external network.

  (2) The route search server 9 generates route information S5 based on the time-series probe information S3 acquired through the external network and the VICS information S2 acquired from the VICS center 10, and the VICS information S2 and the route information S5. To the external network. The terminal device 204A of the in-vehicle device 2 acquires the VICS information S2 and the route information S5 transmitted to the external network.

In the case of the modification shown in FIG. 10, since the wireless communication by the mobile terminal device 204A is adopted as the uplink means of the probe information S3, the mounting rate cannot be calculated using the detection information of the optical beacon 11. .
Therefore, in the control unit 401 of this modification, the number of vehicles 5 (that is, the number of registered members of the route search server 9) that can transmit the departure point and the destination point as input information of the route information S5, and the registration of all vehicles. The total traffic volume is calculated by applying the ratio with the number of cars to the partial traffic volume.

The reason is that the ratio between the number of registered members and the registered number of all vehicles is considered to be substantially equal to the ratio between the partial traffic volume and the total traffic volume.
As will be described later, the route obtained as a result of the route search by each vehicle 5 itself may be collected by the central device 4 and reflected in the predicted traffic volume. In this case, the route can be transmitted. The ratio between the number of vehicles 5 and the registered number of all vehicles is applied to the partial traffic volume.

[Other variations]
The above-described embodiments (including modifications) are examples and do not limit the scope of rights of the present invention. The scope of the present invention is defined by the terms of the claims, and all modifications within the scope and equivalents of the claims are included in the present invention.
For example, in the above embodiment, the route search server 9 operated independently of the traffic control center performs route search, and the central device 4 of the center acquires the route information S5 generated by the server 9, The central device 4 may generate the route information S5.

In addition, the present invention can be implemented by collecting not only the search results by the route search server 9 but also the results of route searches performed by the respective in-vehicle devices 4.
Furthermore, the present invention is not limited to the case where the central device 4 performs wide area control, and a plurality of traffic signals 1 included in the LAN perform system control or wide area control in a group unit separate from the control by the central device 4. It can also be applied to cases.

Further, the present invention can be applied to a system that performs not only MODERATO control and UTMS control but also other traffic signal control.
In particular, the present invention is effective for prediction control in which a prediction value of a signal waiting delay time is calculated by a simulation method, such as UTMS control. If the present invention is applied to such prediction control, the present invention is effective at the prediction start time. Traffic volume can be grasped more accurately and predictive control can be improved.

DESCRIPTION OF SYMBOLS 1 Traffic signal device 1a Traffic signal control device 1b Signal lamp 2 Car-mounted device 3 Roadside sensor 4 Central device (traffic signal control device)
401 control unit (first and second calculation means, generation means)
402 Display unit 403 Communication unit (acquisition means)
404 Storage Unit 405 Operation Unit 5 Vehicle 9 Route Search Server 11 Optical Beacon Ci Intersection S1 Signal Control Command S2 VICS Information S3 Probe Information S4 Roadside Measurement Information S5 Route Information

Claims (6)

A traffic signal control device that generates a signal control command for controlling the switching timing of the signal light color of a traffic signal device,
Obtaining means for obtaining a route of the vehicle having the result of the route search;
First calculating means for calculating a partial traffic volume for each time zone for the vehicle flowing into the intersection included in the route;
Second calculation means for calculating predicted traffic volume for each time zone for the intersection to be controlled using the partial traffic volume;
Generating means for generating the signal control command based on the predicted traffic volume;
A traffic signal control device comprising:   The second calculation means, for a road without a roadside sensor for detecting roadside measurement information including the number of passing vehicles, the total traffic volume based on a value obtained by multiplying the partial traffic volume of the road by a predetermined ratio, The traffic signal control device according to claim 1, which is adopted as the predicted traffic volume.   The second calculating means, for a road with a roadside sensor for detecting roadside measurement information including the number of vehicles passing through the vehicle, determines a predetermined traffic volume based on the roadside measurement information and the partial traffic volume of the road. The traffic signal control device according to claim 1, wherein a traffic volume obtained from an overall traffic volume based on a value multiplied by a ratio is adopted as the predicted traffic volume. A roadside communication device capable of receiving an uplink transmitted by the vehicle on the road in the control area managed by the own device and detecting the number of vehicles passing at the reception position is installed.
The said 2nd calculation means applies the ratio of the number of uplinks which the said roadside communication apparatus detected, and the said passing number of units to the said partial traffic volume, and calculates the said total traffic volume. Traffic signal control device.   The second calculating means applies the ratio of the number of vehicles capable of transmitting the route or input information necessary for this search to the outside to the registered number of all vehicles to the partial traffic volume, and The traffic signal control device according to claim 2 or 3, which calculates an amount. A computer program for causing a traffic signal control device to execute generation processing of a signal control command for controlling the switching timing of the signal light color of a traffic signal,
Obtaining a route of a vehicle having a route search result;
Calculating a partial traffic volume for each time zone for the vehicle flowing into an intersection included in the route;
Calculating the predicted traffic volume for each time zone for all vehicles flowing into the intersection to be controlled using the partial traffic volume;
Generating the signal control command based on the predicted traffic volume;
A computer program comprising:

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