JP2016170480A - Traffic signal controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for determining a group of vehicles.SOLUTION: A traffic signal controller repeats individual vehicle group determination to determine whether there is a vehicle group in a determination period while shifting the determination period for arrival traffic flow prediction information on each of inflow paths of an intersection where the traffic controller stands, and determines the whole aspect of vehicle groups by integrating the determination results of the individual vehicle group determination. The determination result is stored in a vehicle group determination table. Then, a signal control parameter is changed with the use of the vehicle group determination result.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a traffic signal controller that controls traffic signals using signal control parameters.

  As a traffic signal control at an intersection, a vehicle group that detects a vehicle group composed of a plurality of vehicles and changes signal control parameters such as extension of blue hours so that the vehicle group can pass through the intersection with priority. Sensitive control is known (see, for example, Patent Document 1).

JP-A-8-221690

  By the way, as a method of detecting a vehicle group, as disclosed in the above-mentioned Patent Document 1, a method of determining from a vehicle head interval and a traveling speed of a vehicle sensed by a vehicle sensor is generally used. However, this method determines a vehicle group based on each vehicle detected by the vehicle detector. For this reason, it could be said that the traffic signal control depends entirely on the vehicle detector. In addition, the conventional vehicle group determination method is a method for determining whether a vehicle group continues by focusing only on the front and rear vehicles. Therefore, if there is a vehicle interval that does not satisfy any conditions, the vehicle group is disconnected at that moment. In some cases, however, although the entire vehicle group can be regarded as one vehicle group, it is determined that the vehicle group is cut off and a short vehicle group is continuous.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for realizing a new vehicle group determination method.

The first invention for solving the above-described problems is
A traffic signal controller for controlling traffic signals using given signal control parameters,
The arrival traffic flow prediction information indicating the predicted arrival number of the time series to the own intersection is set while shifting the determination period of the predetermined time portion to determine the existence of the vehicle group in each determination period. A vehicle group determination unit that determines the entire vehicle group by integrating the determination results;
A parameter changing unit that changes the signal control parameter using the determination result of the vehicle group determining unit;
It is a traffic signal control machine equipped with.

  According to the first aspect, the vehicle group can be determined based on the arrival traffic flow prediction information of the own intersection. Specifically, the arrival traffic flow prediction information is set while shifting the determination period to determine the existence of the vehicle group within each determination period, and by integrating the determination results of each determination period, Determine the whole picture. Therefore, a new vehicle group determination method that is completely different from the conventional method can be realized.

More specifically, as a second invention, the traffic signal controller of the first invention,
The vehicle group determination unit determines whether a vehicle group exists in the determination period by determining a predicted arrival vehicle for each unit period included in the determination period.
A traffic signal controller may be configured.

Furthermore, as a third invention, the traffic signal controller of the second invention,
The vehicle group determination unit starts with a unit period that is initially determined to have a predicted arrival vehicle, and ends with a unit period that is determined to have a predicted arrival vehicle at the end, among the unit periods included in the determination period. The unit period from the beginning to the end is determined as the position of the vehicle group within the determination period.
A traffic signal controller may be configured.

  The conventional method for determining a vehicle group is to determine whether or not a vehicle group is continuously formed at the front and back intervals of the sensed vehicle, and sequentially determine each vehicle and extend the vehicle group. The method was common. On the other hand, according to the second or third aspect of the invention, it is possible to realize a completely new vehicle group determination method of determining a vehicle group by determining whether a vehicle exists for each unit period.

  As a fourth aspect of the invention, the vehicle group determination unit configures the second or third traffic signal controller in which the determination period is set so that a unit period in which the predicted arrival number is not zero starts. May be.

  According to the fourth aspect of the invention, the determination period starting from the unit period in which the predicted arrival number is zero is not set, so that the processing load can be reduced.

Further, as a fifth invention, the traffic signal controller according to any one of the first to fourth inventions,
The determination period is a period of 3 seconds to 10 seconds,
A traffic signal controller may be configured.

  According to the fifth aspect of the invention, the determination period can be a period of 3 seconds or more and 10 seconds or less. The determination period is set while shifting. And the determination result of the vehicle group in each determination period is integrated, and the whole image of the vehicle group is determined. Therefore, the length of the determination period is an important factor for determining the vehicle group. According to the fifth aspect, the determination period can be set to a suitable length that is neither too short nor too long.

Further, as a sixth invention, the traffic signal controller according to any one of the first to fifth inventions,
A prediction unit that obtains information on outflow traffic flow from a neighboring intersection and obtains a detection result of a sensor that senses a vehicle flowing into the own intersection to predict the arrival traffic flow prediction information ,
You may comprise the traffic signal controller provided further.

  According to the sixth aspect of the present invention, so-called autonomous decentralized type that predicts arrival traffic flow by acquiring information on outflow traffic flow from neighboring intersections and detection results of a sensor that senses vehicles flowing into its own intersection. In the traffic signal controller, a vehicle group can be determined based on the arrival traffic flow prediction information of its own intersection, and a new vehicle group determination method that achieves the same effects as the first to fifth inventions is realized. Can do.

Installation example of traffic signal controller. Explanatory drawing of individual vehicle group determination. Explanatory drawing of vehicle group determination. An example of a signal control parameter. Explanatory drawing of calculation of the number of stops. Functional block diagram of a traffic signal controller. The flowchart of a traffic signal control process.

[System configuration]
FIG. 1 is an installation example of the traffic signal controller 10 of the present embodiment. In FIG. 1, an intersection 1 to be controlled by the traffic signal controller 10 is a cross intersection where a main road and a secondary road intersect and have four inflow paths A to D. In each of the inflow paths A to D, a vehicular signal lamp 20 for vehicle traffic entering the intersection 1 from the inflow path is installed. In addition, vehicle sensing 30 is installed in each of the inflow paths A and C. FIG. 1 is an example of the intersection 1 and is not limited to the cross intersection, and the present embodiment can be similarly applied to intersections of other shapes such as a three-way intersection and a T-shaped intersection.

  The vehicular signal lamp 20 is installed on an upper part of a pillar or the like installed on the roadside near the intersection 1 so as to face the target vehicle traffic. The display lamp color of the vehicular signal lamp 20 is controlled by the traffic signal controller 10.

  The vehicle detector 30 is installed at a position overlooking the target inflow path from above, on the top of a pillar or the like installed on the road side, and detects the presence or absence of a vehicle passing through a predetermined position in the target inflow path. As the vehicle sensor 30, known sensors such as an ultrasonic type, an optical type, and an image type can be used. The detection result of the vehicle sensor 30 is transmitted to the traffic signal controller 10 at any time.

  The traffic signal controller 10 is installed below or in the vicinity of a pillar to which any of the vehicle signal lamps 20 is attached, and is connected to the vehicle signal lamp 20 and the vehicle detector 30 by wire or wirelessly. ing. The traffic signal controller 10 is an autonomous decentralized traffic signal controller, and the outflow traffic flow prediction information received from the traffic signal controllers 10B, 10B, 10B, 10B at the adjacent intersections 1B, 1B, 1B, 1B. Based on the predicted arrival traffic flow in the near future such as within 5 minutes, the signal control parameter of the own intersection 1 is changed based on the predicted arrival traffic flow. Moreover, the traffic signal controller 10 of this embodiment determines a vehicle group using the prediction information of arrival traffic flow. Then, with reference to the information on the determined vehicle group, the signal control parameter is changed so that the number of vehicles stopped at the intersection 1 is reduced. Therefore, it can be said that the traffic signal controller 10 is a device including a signal control parameter setting device. The intersection 1 to be controlled by the traffic signal controller 10 is hereinafter appropriately referred to as “own intersection”.

[principle]
This will be specifically described. First, the vehicle group arriving at its own intersection is determined for each inflow path. FIG. 2 is a diagram illustrating vehicle group determination, and illustrates vehicle group determination for a certain inflow path. The vehicle group is determined based on the arrival traffic flow prediction information of the inflow path. The arrival traffic flow prediction information is information that predicts the arrival traffic flow that flows into the intersection from the inflow route, and the position of the stop line is 0 second (corresponding to “0 to 1 s” in the figure), and unit time The number of arriving vehicles per unit period divided every second is shown in time series. The arrival traffic flow prediction information is obtained as the sum of the number of arrival vehicles in each unit period after offsetting the outflow traffic flow prediction information from the upstream intersection to the own intersection by the travel time between the intersections. In addition, the number of vehicles arriving within the unit period is based on the outflow traffic flow prediction information, and is therefore multiplied by the probability for each outflow direction such as going straight to the left or right. Therefore, it can take a decimal. Therefore, the arrival traffic flow prediction information is numerical information for each unit period such as “0.0”, “0.8”, “0.0”, “0.5”. However, when the vehicle detector 30 is installed in the inflow path and the detection result of the vehicle detector 30 can be acquired, the actual number of vehicles can be corrected based on the detection result. In this case, for example, the arrival traffic flow prediction information is an integer for each unit period such as “0”, “1”, “0”, “0”.

  In addition, as one of the features of this embodiment, a concept of a determination period is introduced for arrival traffic flow prediction information. Specifically, the determination period of N seconds, which is a predetermined time, is set with respect to the arrival traffic flow prediction information while being shifted by M seconds (N> M) to determine the existence of a vehicle group within each determination period. The whole group is determined by integrating the determination results of each determination period. The determination period is set to 3 seconds or more and 10 seconds or less as a length that can be determined as a certain length of vehicle group that is neither too long nor too short. In the present embodiment, the length of the determination period is 5 seconds (= N), that is, one determination period is constituted by five unit periods. Further, M seconds are set to 1 second, that is, one unit period. In addition, the determination of whether or not there is a vehicle group related to each determination period is referred to as “individual vehicle group determination”. The final vehicle group determination result is generated as a vehicle group determination table.

  FIG. 2 is a diagram for explaining individual vehicle group determination. In the individual vehicle group determination, the total number of arriving vehicles within the target determination period is equal to or greater than a predetermined determination threshold number (in the present embodiment, three (more precisely, 3.0)). Then, it is determined that the vehicle group exists (the vehicle group exists) within the determination period. Here, the number of vehicles arriving in each unit period in the arrival traffic flow prediction information is a small value such as “0.8 vehicles” based on the probability according to the outflow direction of the upstream intersection, or based on the detection result of the vehicle detector 30. It is represented by an integer value such as “1 unit”.

  And about the determination period determined as having a vehicle group, among the unit periods in the determination period, the number of arriving vehicles is a predetermined number condition (in this embodiment, this condition is set to exceed 0). A continuous unit period from the beginning to the end is determined as a vehicle group within the determination period, with the first unit period to be satisfied as the head and the last unit period satisfying the number of units as the end.

  FIG. 2A shows an example in which individual vehicle group determination is performed for the determination period of 3 to 7 seconds. Since the total number of arriving vehicles within the determination period of 3 to 7 seconds is 3.2, it satisfies the condition of 3.0 or more that is the determination threshold number and determines that there is a vehicle group. In addition, the first unit period in which the number of arriving vehicles satisfies the predetermined unit condition is the third second (“3 to 4 s” in the figure), and the last unit period that satisfies the predetermined unit condition is the sixth unit ( Since it is “6 to 7 s” in the figure, the period of 3 to 6 seconds is determined as the vehicle group. Similarly, FIG. 2B shows an example in which individual vehicle group determination is performed for the determination period of the 7th to 11th seconds. Within the determination period of the 7th to 11th seconds, the total number of arriving vehicles is 1.1, and the condition of the determination threshold number of 3.0 or more is not satisfied. To do.

  After such individual vehicle group determination for each determination period is performed, the determination results are integrated to obtain the final vehicle group determination result. An example is shown in FIG. The arrival traffic flow prediction information is shown on the left side of the figure, and the result of the individual vehicle group determination in each determination period set by shifting with respect to the arrival traffic flow prediction information is shown in the center of the figure. The result of each individual vehicle group determination is summed up for each corresponding unit period (statistic combination processing under OR condition), and if it is determined as “car group present” by any individual vehicle group determination, the unit period is Judged as “car group”. The right side of the figure shows a vehicle group determination table as a final vehicle group determination result. Including the period of 3 to 7 seconds determined to be in the vehicle group in FIG. 2A, it is determined that the vehicle group is in the first to sixth seconds.

  In the vehicle group determination of the present embodiment, individual vehicle group determination is performed for each of a plurality of determination periods shifted by unit periods. In other words, since the judgment periods are set while being partially overlapped, there are exceptions such as the first 0 second unit period, but basically, individual vehicle group judgments are performed multiple times for each unit period. Will be. Therefore, even in a unit period in which it is not determined that there is a vehicle group in a certain determination period, the same unit period may be determined to be in a vehicle group in another determination period. Naturally, the traveling vehicle travels between the vehicles, so whether the length of the distance between the vehicles is considered to be continued or whether the vehicle has been cut depends on the determination criterion. However, in the conventional vehicle group determination method, the determination is made only once for the space between the vehicles. On the other hand, in this embodiment, a plurality of individual vehicle group determinations are performed for each unit period. For this reason, possibility that it will be judged as a vehicle group increases, and the likelihood (it can also be said to be adaptability) which can be regarded as a vehicle group as a whole can be improved.

  Since the vehicle group determination table is a total result obtained by integrating the determination results of the individual vehicle group determinations for each unit period, the vehicle group is determined every 1 second, which is the unit period, with the stop line position at the 0th second. It becomes information indicating whether or not there exists in time series.

  Next, the traffic signal controller 10 at its own intersection changes the signal control parameter using the vehicle group determination result. Specifically, a simple signal control simulation according to each of a plurality of signal control parameter candidates (provisional signal control parameters) is performed. Then, using the number of stops at the own intersection in one cycle as one of the selection criteria, a signal control parameter candidate that satisfies a predetermined best condition is selected and changed to a signal control parameter according to the selected signal control parameter candidate. Actually control the traffic signal.

  A method for changing the signal control parameter will be described in order. FIG. 4A shows an example of the current level table at the own intersection that is the control target of the traffic signal controller 10, and FIG. 4B shows the control parameters for realizing the current level of FIG. 4A. An example of the change range is shown. According to FIG. 4 (a), as traffic signal control of the own intersection, it is determined to alternately display the present indication 1φ for giving the right of passage to the main road and the present indication 2φ for giving the right of passage to the secondary road. Yes. The present 1φ is composed of three steps (steps) of the main road blue (stage 1), the main road yellow (stage 2), and all red (stage 3), and the present 2φ is the follower blue (stage 4). It is composed of three tiers: secondary road yellow (story 5) and all red (story 6). That is, one cycle is composed of six levels. In the present embodiment, the signal control parameter has a fixed cycle length and can change the split. That is, it is assumed that the signal control parameter is changed by changing the parameter related to the split. The split is changed by changing the display seconds of the floors 1 and 4 which are green signals. The display seconds of the floors 1 and 4 can be changed in units of one second within a predetermined number of seconds. However, in order to make the cycle length constant, when the display time of the floor 1 is increased, the display time of the floor 4 is shortened. The plurality of signal control parameter candidates are signal control parameters obtained by changing the parameters related to the split.

  Next, a simple signal control simulation based on each signal control parameter candidate is performed. The signal control simulation is performed by predicting the number of staying in time series for each inflow path to the intersection using the arrival traffic flow prediction information and the vehicle group determination result. However, the number of staying in the vehicle group is calculated by weighting. Then, out of the number of stays in time series, the number of stays immediately before the signal to which the right of passage is given is taken as the number of stops, and the number of stops in all the inflow paths for at least one signal cycle is calculated.

  The reason for weighting the number of stays in the vehicle group is to reduce the environmental load. It is known that the amount of exhaust gas emitted from a gasoline vehicle is greater during acceleration travel than during constant speed travel. In addition, even if the vehicle is an electric vehicle, a hybrid vehicle, or an automobile that stops idling when it stops, it needs to consume more energy than starting without stopping after starting from the stop. Therefore, the environmental load becomes high. Therefore, in order to reduce the overall environmental load, in this embodiment, the number of staying in the vehicle group is weighted.

  A specific example will be described. FIG. 5 is a diagram illustrating a processing procedure up to calculation of the number of stops. FIG. 5 shows the calculation of the number of stops for a certain inflow channel. Based on the arrival traffic flow prediction information, the outflow possibility table, and the vehicle group determination table, the number of staying units is calculated for each unit period.

  In the outflow allowance table, the right of passage is granted for each unit period, assuming that the right of access (access right to own intersection) is given to the inflow route, and that the case where it is not given is “impossible”. It is information indicating whether or not it is in time series. Whether the outflow is possible or not is determined by the signal control parameter candidate, and if the corresponding time indication is a green signal, outflow is possible and “possible”, otherwise, outflow is impossible and “no flow” is set.

  If the possibility of outflow is “possible” for each unit period, the number of vehicles arriving in the unit period to be processed is added to the number of staying units in the previous unit period, and a predetermined number of outflows per unit time (this embodiment) Then, 1.0 is subtracted) to calculate the number of stays in the unit period to be processed. Further, if the outflow possibility is “impossible”, the number of staying vehicles is calculated by adding the number of arriving vehicles in the unit period to be processed to the number of staying units in the immediately preceding unit period. Further, when adding the number of arriving vehicles in the unit period to be processed, for a unit period determined as “vehicle group present” in the vehicle group determination table, a predetermined weight coefficient k (in this embodiment, , K = 2), and the weighted number is added. Although the weighting factor k is “2”, this is an example, and “1.5” or “3” may be used as long as the number is larger than one.

  Then, when the number of staying units for each unit period is calculated, the number of staying units in the unit period immediately before the signal for granting the right to pass, that is, immediately before the flowability is changed from “impossible” to “possible” To do. In FIG. 5, the possibility of outflow is “impossible” until the 11th second, and transitions to “outflowable” in the 12th second, so the unit period of the 11th second (“11-12s” in FIG. 5). The number of stays is the number of stops.

  This number of stops is calculated for each of the inflow channels. Then, the total number of stops for each inflow path is set as the total number of stops at the own intersection related to the one signal control parameter candidate. This is executed for each signal control parameter candidate. Then, the signal control parameter candidate that minimizes the total number of stopped vehicles is selected as a parameter used for traffic signal control among the signal control parameter candidates.

  Although the calculation of the number of stops is described as the number of stops for one signal cycle, it is needless to say that the number of stops for a plurality of signal cycles may be obtained.

  As described above, since the signal control parameter candidate having the smallest total number of stops on all the inflow paths for the integer number of signal cycles is set as the parameter used for actual traffic signal control, the environmental load is reduced overall. The signal control can be realized. Unlike partial and fragmentary signal control technology, such as signal control that allows the vehicle group to pass through without interruption, or signal control that gives priority to the main road. Specific signal control that comprehensively considers such traffic can be realized.

[Function configuration]
FIG. 6 is a block diagram showing a functional configuration of the traffic signal controller 10. According to FIG. 6, the traffic signal controller 10 functionally includes an operation unit 102, a display unit 104, a clock unit 106, a communication unit 108, a processing unit 200, and a storage unit 300. Is done. Since the traffic signal controller 10 is also a device for setting signal control parameters, it can be said that the traffic signal controller 10 includes a signal control parameter setting device.

  The operation unit 102 is realized by an input device such as a button switch or a touch panel, for example, and outputs an operation signal according to the operation of the administrator of the traffic signal controller 10 to the processing unit 200. The display unit 104 is realized by a display device such as an LCD or a touch panel, for example, and performs various displays according to display signals from the processing unit 200. In addition, the operation part 102 and the display part 104 are accommodated in the housing | casing of the traffic signal controller 10, and ordinary people, such as a pedestrian, cannot operate and visually recognize.

  The clock unit 106 measures the current time and the elapsed time from the specified timing. The communication unit 108 is realized by a wired or wireless communication device, and performs wired communication or wireless communication with an external device (mainly, the traffic signal controller 10B or the vehicle sensor 30 at an adjacent intersection).

  The processing unit 200 is realized by an arithmetic unit such as a CPU, for example, and stores programs and data stored in the storage unit 300, information received from the traffic signal controller 10B at an adjacent intersection, detection result information from the vehicle sensor 30, and the like. Based on this, overall control of the traffic signal controller 10 is performed. The processing unit 200 includes an arrival traffic flow prediction unit 202, an outflow traffic flow prediction unit 204, a vehicle group determination unit 206, a parameter change unit 208, and a signal control unit 210.

  The arrival traffic flow prediction unit 202 predicts the arrival traffic flow for each inflow path of the own intersection based on the outflow traffic flow prediction information 304 of the adjacent intersection received from the traffic signal controller 10B of the adjacent intersection, and arrives at the arrival traffic flow. Prediction information 306 is generated. Specifically, for each inflow path, the outflow traffic flow from the corresponding upstream intersection is delayed by the travel time between the intersections to be the arrival traffic flow. In addition, when the vehicle detector 30 is installed in the inflow path, the arrival traffic flow prediction information 306 of the inflow path is corrected to the actual number of vehicles based on the detection result of the vehicle sensor 30.

  The outflow traffic flow prediction unit 204 includes the arrival traffic flow predicted by the arrival traffic flow prediction unit 202 (arrival traffic flow prediction information 306), and the signal control parameter (set signal control parameter 328) changed / set by the parameter change unit 208. ), The outflow traffic flow from the own intersection to each direction is predicted, and the outflow traffic flow prediction information 308 is generated. Specifically, for each path that can flow out, for each unit period within a predetermined time range, determine whether or not the right of passage is given from the signal control parameter, calculate the number of staying, and in advance The outflow traffic flow according to the direction of travel is calculated according to the determined rate of travel according to the direction of travel (such as turning right / left or going straight). The generated outflow traffic flow prediction information 308 for each outflow route is transmitted to the traffic signal controller 10 at the downstream intersection.

  The vehicle group determination unit 206 determines a vehicle group for each inflow route based on the arrival traffic flow (arrival traffic flow prediction information 306) predicted by the arrival traffic flow prediction unit 202. Specifically, with respect to the arrival traffic flow prediction information 306, the individual vehicle group determination for determining whether the vehicle group exists within the determination period is repeated while shifting the determination period by 1 second as a unit period. The determination results of the individual vehicle group determination are integrated to generate a vehicle group determination table 310 that is the final vehicle group determination. In individual vehicle group determination, the presence / absence of a vehicle group within the determination period is determined based on whether or not the total number of vehicles arriving in the determination period is equal to or greater than a predetermined determination threshold number. In the unit period within the determination period, the period from the first unit period in which the number of vehicles arrives that satisfies the predetermined number of units to the last unit period that satisfies the predetermined number of units is determined as a vehicle group (see FIG. 2 and 3).

  The parameter changing unit 208 changes the traffic signal control parameter related to the own intersection based on the arrival traffic flow prediction information 306 for each inflow route and the vehicle group determination table 310. Specifically, first, the value of the signal control parameter is changed within a predetermined range to generate a plurality of signal control parameter candidates. Among the signal control parameters, the changeable parameter type and the change range thereof are stored as parameter setting range information 314. In the present embodiment, the cycle length is fixed, and the split time is changed by changing the green signal display time (see FIG. 4).

  Then, for each of these signal control parameter candidates, the total number of stops in one cycle at the own intersection is calculated. That is, for each inflow path, the outflow possibility table 320 is generated by determining whether or not outflow is possible for each unit period according to the signal control parameter candidate, and the arrival traffic flow prediction information 306, the vehicle group determination table 310, and the outflow possibility table 320 are generated. Based on the above, the number of staying units per unit period is calculated. At this time, for the unit period determined to be a vehicle group, the number of arriving vehicles is multiplied by a predetermined weighting factor k and added to the number of staying vehicles. And let the sum total of the stop number of all the inflow paths be the total stop number of the own intersection. When the total number of stops is calculated for all signal control parameter candidates, the signal control parameter candidate that minimizes the total number of stops is selected and set as the signal control parameter used for traffic signal control. The set signal control parameter is stored as a set signal control parameter 328.

  The signal control unit 210 controls the vehicle signal lamp 20 at its own intersection according to the signal control parameter changed / set by the parameter changing unit 208.

  The storage unit 300 is realized by a storage device such as a ROM, a RAM, or a hard disk, and a system program for the processing unit 200 to control the traffic signal controller 10 in an integrated manner, a program and data for realizing each function, and the like. Is remembered. In addition, it is used as a work area of the processing unit 200 and temporarily stores calculation results executed by the processing unit 200 according to various programs, data received via the communication unit 108, and the like. In the present embodiment, the storage unit 300 includes a traffic signal control program 302, outflow traffic flow prediction information 304 at adjacent intersections, arrival traffic flow prediction information 306, outflow traffic flow prediction information 308, and a vehicle group determination table 310. In addition, a current floor table 312, parameter setting range information 314, parameter candidate information 316, and a setting signal control parameter 328 are stored.

  The parameter candidate information 316 is information regarding the signal control parameter candidates generated by the parameter changing unit 208. For each of the signal control parameter candidates 318, the outflow propriety table 320, the staying number information 322, the number of stops 324, and the number of all stops 326 are stored in association with each other.

[Process flow]
FIG. 7 is a flowchart for explaining the flow of the traffic signal control process. This process is a process executed by the processing unit 200 according to the traffic signal control program 302, and is repeatedly executed every predetermined time (for example, every 5 seconds or every 10 seconds).

  First, the arrival traffic flow prediction unit 202 predicts the arrival traffic flow based on the outflow traffic flow prediction information 304 of the adjacent intersection for each inflow path of its own intersection, and generates arrival traffic flow prediction information 306 (step S1). . Next, the vehicle group determination unit 206 determines a vehicle group for each inflow path based on the arrival traffic flow prediction information 306, and generates a vehicle group determination table 310 (step S3). Subsequently, the parameter changing unit 208 changes the blue time and generates a plurality of signal control parameter candidates (step S5). Then, loop A processing is performed for each of these signal control parameter candidates.

  In loop A, the process of loop B is performed for each inflow path at its own intersection. In loop B, according to the target signal control parameter candidate, it is determined whether the target inflow path is outflow per unit period or not. A table 320 is generated (step S7). Next, based on the arrival traffic flow prediction information 306 on the target inflow path and the vehicle group determination table 310, the number of vehicles arrived is multiplied by a weighting factor k corresponding to the presence / absence of the vehicle group for each unit period. The number of units is calculated, and the staying unit number information 322 is generated (step S9). Further, at this time, according to the outflow propriety table 320, for the unit period in which the outflow is “permitted”, the remaining number is calculated by subtracting the number of outflows. Then, the number of stays immediately before the right to pass in the generated staying number information 322 is calculated as the number of stops (step S11).

  When the process of Loop B for all the inflow paths is performed, the total of the calculated number of stops for each inflow path is calculated as the total number of stops at the own intersection (step S13). When the process of loop A for all signal control parameter candidates is performed, a signal control parameter candidate that minimizes the total number of stops is selected and set as a signal control parameter used for traffic signal control (step S15). When the above processing is performed, the traffic signal control processing ends.

[Function and effect]
As described above, the traffic signal controller 10 of the present embodiment determines the individual vehicle group whether the vehicle group exists within the determination period with respect to the arrival traffic flow prediction information for each inflow path at the intersection. Are repeated while shifting one second at a time, and the determination results of the individual vehicle group determination are integrated to determine the entire vehicle group. Next, the calculation of the total number of stops at the own intersection in one cycle when the signal control according to the signal control parameter candidates is performed is executed for all the signal control parameter candidates. Then, a signal control parameter candidate that minimizes the total number of stops is selected and set as a signal control parameter used for traffic signal control. The total number of stops is the sum of the number of stops in each inflow route. The number of stops in each inflow route is based on the predicted arrival traffic flow and gives a predetermined weight to the number of arrival vehicles according to the presence / absence of the vehicle group. The number of staying is calculated, and the number of staying immediately before the signal to which the right of passage is given is calculated as the number of stopping of the inflow path.

  Thereby, with respect to the arrival traffic flow prediction information of the own intersection, the determination period is set so as to partially overlap, the existence of the vehicle group within each determination period is determined, and the determination result of each determination period is determined. By integrating, a new vehicle group determination method such as determining the entire vehicle group is realized.

  Also, by calculating the number of stays in the vehicle group and calculating the total number of stops at the intersection, selecting and setting the signal control parameter that minimizes the total number of stops, all routes related to the own intersection It is possible to realize signal control that can reduce the total number of times the vehicle is stopped in traffic, that is, signal control that can reduce the environmental load.

[Modification]
It should be noted that embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

(A) Individual vehicle group determination In the above-described embodiment, the individual vehicle group determination is performed while shifting the determination period by one second with respect to the arrival traffic flow prediction information (see FIG. 3). The determination period is set only when the unit period that satisfies the predetermined number condition (in this embodiment, exceeds 0, that is, it is not zero) is set at the beginning, and the individual vehicle group determination is performed. It is good to do. For example, in the determination period of the 7th to 11th seconds shown in FIG. 2B, the number of arrival vehicles in the unit period of the 7th second which is the first unit period is 0 and does not satisfy the number condition, so the determination period is set. No individual vehicle group determination is performed. Thereby, the processing load can be reduced. However, since the individual vehicle group determination is always performed at least once for the unit period in which the number of arrival vehicles satisfies the number condition, and the individual vehicle group determination is performed more times for the part where the vehicles are connected, Overall, the accuracy of the vehicle group determination can be kept high.

(B) Selection Criteria In the above-described embodiment, the total number of stops is used as a criterion for selecting a signal control parameter used for traffic signal control from among a plurality of signal control parameter candidates. Further, a delay cost may be introduced. The delay cost is the sum of products of the stop time (staying time) and the number of vehicles stopped at the intersection. For example, when two vehicles are stopped for 10 seconds, the delay cost is 20 [units / second]. In this case, the signal control parameter is selected and set under the best condition that the total number of stopped vehicles satisfies the predetermined condition and the delay cost satisfies the predetermined condition.

  Specifically, the delay cost for each inflow path in one signal cycle period is calculated based on the staying number information calculated by weighting according to the presence / absence of the vehicle group (see FIG. 5). In total, the delay cost of the entire intersection (referred to as “first delay cost”) is calculated. Similarly, for each signal control parameter candidate, the number of stays when weighting based on the presence / absence of the vehicle group is not performed is calculated, and based on this staying number, the overall delay of the own intersection in one signal cycle period is calculated. Cost (referred to as “second delay cost”) is calculated. Since the weighting is performed according to the presence / absence of the vehicle group, the first delay cost is equal to or higher than the second delay cost.

  Then, after selecting a signal control parameter candidate that minimizes the total number of stops from among a plurality of signal control parameter candidates, the difference between the first delay cost and the second delay cost of the selected signal control parameter candidate is calculated. calculate. If this cost difference is less than or equal to a predetermined value, the selected signal control parameter candidate is set to be used for traffic signal control. On the other hand, if the cost difference exceeds a predetermined value, a signal control parameter candidate that minimizes the second delay cost is selected from the signal control parameter candidates, and this is set to be used for traffic signal control.

(C) Signal control parameter setting device In the above-described embodiment, since the traffic signal controller 10 changes and sets the signal control parameter, the traffic signal controller 10 is also described as a signal control parameter setting device. The signal management parameter setting device may be configured to be carried by the central management device.

  That is, among the processes performed by the processing unit 200 of the traffic signal controller 10 described above, processes other than the processes performed by the signal control unit 210 are installed in the control center, and a plurality of traffic signal controllers and communication lines provided at each intersection. It may be performed by a central management device connected via the network. More specifically, the central management device has an arrival traffic flow prediction unit 202, an outflow traffic flow prediction unit 204, a vehicle group determination unit 206, and a parameter change unit 208, and causes each intersection to function. do it. In this case, the central control unit predicts the arrival traffic flow and the outflow traffic flow for each intersection based on the detection signal of each vehicle sensor, and determines the vehicle group based on the predicted arrival traffic flow. Then, the signal control parameters at each intersection are changed and set, and transmitted to the corresponding traffic signal controller. The traffic signal controller performs traffic signal control according to the signal control parameters received from the central management device.

  Note that the arrival traffic flow prediction unit 202 and the outflow traffic flow prediction unit 204 are left in the processing performed by the processing unit 200 of the traffic signal control unit 10, and the arrival traffic flow and the outflow traffic flow are predicted for each intersection. The traffic signal controller at the intersection may be used. In this case, each traffic signal controller transmits the predicted arrival traffic flow and outflow traffic flow information to the central management device, and the central management device receives the arrival traffic flow prediction information of each intersection received from each traffic signal controller. Based on the above, the vehicle group is determined, the signal control parameter is changed / set, and transmitted to the corresponding traffic signal controller.

(D) Signal Control Parameter Candidates In the above-described embodiment, the signal control parameter candidate 318 has been described as being generated. However, the signal control parameter candidate 318 may be stored in advance. In that case, step S5 in FIG. 7 can be omitted.

(E) Unit period and determination period In the above-described embodiment, the length of the unit period is 1 second and the length of the determination period is five unit periods, that is, 5 seconds. However, this is an example. Of course, other lengths may be used. However, in order to set the determination period with a partial overlap, the determination period of N seconds is set to be shifted by M seconds (N> M, where N and M are greater than 0 and may include decimals). It needs to be possible.

DESCRIPTION OF SYMBOLS 10 Traffic signal controller 102 Operation part, 104 Display part, 106 Clock part, 108 Communication part 200 Processing part 202 Arrival traffic flow prediction part, 204 Outflow traffic flow prediction part 206 Vehicle group determination part, 208 Parameter change part, 210 Signal control Section 300 Storage section 302 Traffic signal control program 304 Outflow traffic flow prediction information of adjacent intersection 306 Arrival traffic flow prediction information, 308 Outflow traffic flow prediction information 310 Vehicle group determination table 312 Current deck, 314 Parameter setting range information,
316 Parameter candidate information 318 Signal control parameter candidate, 320 Outflow propriety table 322 Staying number information, 324 Stopping number, 326 Total stopping number 328 Setting signal control parameter 20 Vehicle signal lamp 30 Vehicle detector

Claims (6)

A traffic signal controller for controlling traffic signals using given signal control parameters,
The arrival traffic flow prediction information indicating the predicted number of arrivals in time series at the intersection is set while shifting the determination period for a predetermined time to determine the existence of the vehicle group in each determination period, A vehicle group determination unit that determines the entire vehicle group by integrating the determination results;
A parameter changing unit that changes the signal control parameter using the determination result of the vehicle group determining unit;
Traffic signal control machine equipped with. The vehicle group determination unit determines whether a vehicle group exists in the determination period by determining a predicted arrival vehicle for each unit period included in the determination period.
The traffic signal controller according to claim 1. The vehicle group determination unit starts with a unit period that is initially determined to have a predicted arrival vehicle, and ends with a unit period that is determined to have a predicted arrival vehicle at the end, among the unit periods included in the determination period. The unit period from the beginning to the end is determined as the position of the vehicle group within the determination period.
The traffic signal controller according to claim 2. The vehicle group determination unit sets the determination period so that the predicted arrival number is a unit period that is not zero.
The traffic signal controller according to claim 2 or 3. The determination period is a period of 3 seconds to 10 seconds,
The traffic signal controller according to any one of claims 1 to 4. A prediction unit that obtains information on outflow traffic flow from a neighboring intersection and obtains a detection result of a sensor that senses a vehicle flowing into the own intersection to predict the arrival traffic flow prediction information ,
The traffic signal controller according to any one of claims 1 to 5, further comprising:

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