JP2016170481A - Traffic signal controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for determining a group of vehicles and to perform new traffic signal control using a result of the determination.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 vehicle groups by integrating the determination results of the individual vehicle group determination. The individual vehicle group determination includes first individual vehicle group determination based on the arrival timing of a specific vehicle and second individual vehicle determination based on the arrival traffic flow prediction information. 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 4

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 and performing a new traffic signal control using the determination result. That is.

The first invention for solving the above-described problems is
A traffic signal controller for controlling traffic signals using given signal control parameters,
A specific vehicle arrival prediction unit that predicts a predicted arrival timing of the specific vehicle at the self-intersection using a detection result of a specific vehicle detector that detects a specific vehicle that is a medium-sized vehicle or a large vehicle flowing into the self-intersection;
Based on the predicted arrival traffic flow information indicating the predicted number of arrivals in time series to the own intersection, a first continuous time range in which the vehicle may arrive following the predicted arrival timing is determined as the position where the vehicle group exists. A vehicle group determination unit;
A parameter changing unit that changes the signal control parameter using the presence position of the vehicle group;
It is a traffic signal control machine equipped with.

  According to the first aspect, the vehicle group can be determined based on the predicted arrival timing of the specific vehicle at the own intersection. Since the specific vehicle observes safe driving and the acceleration / deceleration tends to be gentle, the vehicle often continues behind the specific vehicle. Therefore, the vehicle group is determined using the specific vehicle as one guide. Specifically, the predicted arrival timing of the specific vehicle at its own intersection is predicted using the detection result of the vehicle sensor, and the vehicle may arrive after the predicted arrival timing of the specific vehicle at its own intersection. The time range is determined as the position where the vehicle group is present. Therefore, a new vehicle group determination method that is completely different from the conventional method can be realized. Further, by treating the specific vehicle as the head of the vehicle group, for example, it is possible to control the traffic signal at the intersection so that the group of vehicle groups following the specific vehicle pass preferentially.

More specifically, as a second invention, the traffic signal controller of the first invention,
The first vehicle group determination unit determines the possibility of arrival of the vehicle for each unit period, and the range of continuous unit periods in which the vehicle may arrive following the unit period corresponding to the predicted arrival timing. Is determined as the continuous time range,
A traffic signal controller may be configured.

As a third invention, the traffic signal controller of the first or second invention,
A second vehicle group determination unit that determines the presence of a vehicle group within each determination period by shifting the determination period for a predetermined time with respect to the predicted arrival traffic flow information;
An integration unit that integrates the determination result of the first vehicle group determination unit and the determination result of the second vehicle group determination unit;
You may comprise the traffic signal controller provided further.

  According to the third aspect of the invention, the vehicle group is determined by a logic different from the determination result for determining a group of vehicle groups following the specific vehicle, and the final vehicle group determination is performed by integrating the determination results. be able to. Specifically, it is possible to add another logic for setting the arrival traffic flow prediction information while shifting the determination period and determining the existence of the vehicle group within each determination period.

As a fourth invention, the traffic signal controller of the third invention,
The determination period is a period of 3 seconds to 10 seconds,
A traffic signal controller may be configured.

  According to the fourth 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 so that a part thereof overlaps. And the determination result of the vehicle group in each determination period is integrated, and a vehicle group is determined. Therefore, the length of the determination period is an important factor for determining the vehicle group. According to the fourth invention, the determination period can be set to a suitable length that is neither too short nor too long.

As a fifth invention, the traffic signal controller according to any one of the first to fourth inventions,
A prediction unit for obtaining information on outflow traffic flow from a neighboring intersection and predicting the arrival prediction traffic flow information;
You may comprise the traffic signal controller provided further.

  According to the fifth aspect of the invention, in the so-called autonomous decentralized traffic signal controller that obtains the information of the outflow traffic flow from the neighboring intersection and predicts the arrival traffic flow, the same as in the first to fourth aspects of the invention It is possible to realize a new vehicle group determination method that exhibits the effects.

Installation example of traffic signal controller. Explanatory drawing of 1st individual vehicle group determination. Explanatory drawing of a 2nd 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 and a specific vehicle detector 30 for vehicle traffic entering the intersection 1 from the inflow path are installed. 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 specific vehicle detector 30 is installed at a position overlooking the target inflow path from above on the upper part of a pillar or the like installed on the road side, and detects the presence or absence of a specific vehicle passing through a predetermined position in the target inflow path. To do. The specific vehicle is a medium-sized vehicle or a large vehicle such as a bus or a truck. The specific vehicle sensor 30 can be configured using a known sensor such as an ultrasonic type, an optical type, and an image type. For example, when the vehicle length is obtained from the continuous time when the passing vehicle is present and the vehicle traveling speed based on the presence / absence of the passing vehicle at the sensing target position and the vehicle length is a predetermined length or more, The passing vehicle is determined as a “specific vehicle”. The traveling speed of the vehicle may be a predetermined speed or a measured value. The detection signal of the specific vehicle detector 30 is transmitted to the traffic signal controller 10 at any time. In the present embodiment, for simplicity of explanation, it will be described that the specific vehicle sensor 30 is installed in all the inflow paths A to D, but in some directions such as installed only on the main road. The present invention can also be applied to a case where only the projector is installed.

  The traffic signal controller 10 is installed below or near a pillar to which any of the vehicle signal lamps 20 is attached, and is connected to the vehicle signal lamp 20 and the specific vehicle detector 30 by wired or wireless communication. Has been. 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. The intersection 1 to be controlled by the traffic signal controller 10 is hereinafter appropriately referred to as “own intersection”.

  Moreover, the traffic signal controller 10 of this embodiment determines a vehicle group using the prediction information of arrival traffic flow and the arrival information of a specific vehicle. 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.

[principle]
The principle of this embodiment will be described.
First, the vehicle group arriving at its own intersection is determined for each inflow path. 2-4 is a figure explaining vehicle group determination, and has shown vehicle group determination about one certain inflow path. The vehicle group is determined based on arrival traffic flow prediction information of the inflow path and specific vehicle arrival information. 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”.

  The specific vehicle arrival information is information on a specific vehicle that arrives at its own intersection from the inflow route, and is configured to indicate the number of arrivals of the specific vehicle per unit period in time series with the position of the stop line as the 0th second. Is done. The number of arrivals of the specific vehicle is the actual number of vehicles obtained from the detection signal of the specific vehicle detector 30 and is an integer such as “0” or “1”.

  In addition, as one of the features of this embodiment, the concept of a determination period is introduced. 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. The individual vehicle group determination includes a first individual vehicle group determination and a second individual vehicle group determination.

The first individual vehicle group determination will be described.
FIG. 2 is a diagram for explaining the first individual vehicle group determination. As shown in FIG. 2, in the first individual vehicle group determination, when a specific vehicle exists within the target determination period based on the specific vehicle arrival information, the vehicle group exists within the determination period ( It is determined that there is a car group. Then, for the determination period determined as the presence of the vehicle group, the first unit period in which the specific vehicle exists in the unit period within the determination period starts, and the number of arrival vehicles in the arrival traffic flow prediction information for the same determination period Is the last unit period that satisfies the predetermined number condition (in this embodiment, this condition is greater than 0), and the continuous unit period from the beginning to the end is the vehicle within the determination period. Judge as a group. That is, a continuous time range that is a continuous unit period in which the vehicle may arrive after the specific vehicle is determined as the position of the vehicle group.

  FIG. 2A shows an example in which the first individual vehicle group determination is performed for the determination period of the first to fifth seconds. It is determined that the specific vehicle is present in the unit period of the first second (“1 to 2 s” in the figure) within the determination period of the first to fifth seconds, and the vehicle group is present. The first unit period in which the specific vehicle exists is the first second (“1 to 2 s” in the figure), and in the arrival traffic flow prediction information for the same determination period, the last unit period that satisfies the predetermined number condition Is the 5th second ("5-6s" in the figure), the period of the 1st-5th is determined as the vehicle group.

  FIG. 2B shows an example in which the first individual vehicle group determination is performed for the determination period of the fifth to ninth seconds. Since the specific vehicle does not exist within the determination period of the fifth to ninth seconds, in the first individual vehicle group determination, it is determined that there is no vehicle group during this period.

Next, the second individual vehicle group determination will be described.
FIG. 3 is a diagram illustrating the second individual vehicle group determination. As shown in FIG. 3, in the second individual vehicle group determination, in the arrival traffic flow prediction information, the total number of arrival vehicles within the target determination period is a predetermined determination threshold number (in this embodiment, three ( More precisely, it is assumed that the vehicle is 3.0).)) If it is above, it is determined that the vehicle group exists (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 represented by a small value such as “0.8” based on the probability of each upstream intersection according to the outflow direction.

  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. 3A shows an example in which the second 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 ( In the second individual vehicle group determination, the period of the third to sixth seconds is determined as the vehicle group. Similarly, FIG. 3B shows an example in which the second individual vehicle group determination is performed for the determination period of 7 to 11 seconds. In the determination period of 7 to 11 seconds, the total number of arrival vehicles is 1.1 and does not satisfy the condition of the determination threshold number of 3.0 or more, so in the second individual vehicle group determination, It is determined that there is no vehicle group during this determination period.

  After performing such first and second individual vehicle group determinations for each determination period, the determination results are integrated into a final vehicle group determination result. An example is shown in FIG. The arrival traffic flow prediction information and the specific vehicle arrival information are shown on the left side of the figure, and the results of the first individual vehicle group determination and the second individual vehicle group determination in each determination period set in a shifted manner are shown in the center of the figure. Show. 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.

  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.

  Since the first individual vehicle group determination and the second individual vehicle group determination are performed as the individual vehicle group determination, the determination results may be different. For example, the determination result in the determination period of 0 to 4 seconds is that there is a vehicle group in the first individual vehicle group determination, but there is no vehicle group in the second individual vehicle group determination. In the first individual vehicle group determination, the vehicle group is determined based on whether a specific vehicle exists within the determination period. In the second individual vehicle group determination, the predicted arrival number in the determination period is equal to or greater than a predetermined determination threshold number. The vehicle group is determined according to whether there is any. That is, when a specific vehicle exists within the determination period, it is always determined that “there is a vehicle group” even if the predicted arrival number within the determination period is less than the determination threshold number. Since the specific vehicle observes safe driving and the acceleration / deceleration tends to be gentle, the vehicle often continues behind the specific vehicle. Therefore, using the specific vehicle as a guide, if the specific vehicle exists, it is determined that the vehicle group exists.

  Moreover, since the signal control parameter is changed using the vehicle group determination result as described later, for example, it is possible to realize signal control that preferentially passes the vehicle group through the intersection. If the head of the vehicle group is a specific vehicle, the traffic flow of the entire road traffic including the intersection can be smoothly promoted by controlling the signal to pass the specific vehicle as much as possible.

  Further, 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. That is, although there are exceptions such as the first unit period of 0 seconds, basically, the individual vehicle group determination is performed a plurality of times for each unit period. 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.

Next, the principle of changing the signal control parameter will be described.
The traffic signal controller 10 at its own intersection changes the signal control parameter using the vehicle group determination result described above. 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. 5A shows an example of the current level table at the own intersection which is the control target of the traffic signal controller 10, and FIG. 5B shows the control parameters for realizing the current level of FIG. 5A. An example of the change range is shown. According to FIG. 5 (a), as traffic signal control of the own intersection, it is determined to alternately display the present indication 1φ that gives the right of passage to the main road and the present indication 2φ that gives 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. 6 is a diagram for explaining the processing procedure up to the calculation of the number of stops. FIG. 6 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. The possibility of outflow is determined by the signal control parameter candidates. If the current time indication is a green signal, outflow is possible and “permitted”, otherwise the outflow is impossible and “impossible” 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. Further, the value of the weighting factor k may be different depending on whether the first individual vehicle group determination result or the second individual vehicle group determination result is determined as “the vehicle group is present”. For example, for the unit period determined as “vehicle group present” in the first individual vehicle group determination result, for the unit period determined as “vehicle group present” in the second individual vehicle group determination result, The weighting factor k2 is set to a weighting factor k3 for a unit period determined to be “car group present” as a result of both determinations. At this time, k3 can be a larger value of k1 and k2. Further, when k1> k2, the first individual vehicle group determination result can be emphasized.

  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. 6, whether the outflow is possible is “impossible” until the 11th second, and has transitioned to “possible” at the 12th second, so the unit period of the 11th second (“11-12s” in FIG. 6) 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. 7 is a block diagram showing a functional configuration of the traffic signal controller 10. According to FIG. 7, 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.

  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 specific vehicle sensor 30 at an adjacent intersection).

  The processing unit 200 is realized by an arithmetic device such as a CPU, for example, and 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 specific vehicle sensor 30, and the like. Based on the above, 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 specific vehicle arrival prediction unit 206, a vehicle group determination unit 208, a parameter change unit 214, a signal control unit 216, Have

  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.

  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 330) changed / set by the parameter change unit 214. ), 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 specific vehicle arrival prediction unit 206 generates specific vehicle arrival information 310 by predicting the arrival timing of the specific vehicle at the own intersection based on the detection signal of the specific vehicle detector 30 for each inflow path of the own intersection. To do.

  The vehicle group determination unit 208 includes a first vehicle group determination unit 210 and a second vehicle group determination unit 212.

  The first vehicle group determination unit 210 determines the arrival traffic flow predicted by the arrival traffic flow prediction unit 202 (arrival traffic flow prediction information 306) and the specific vehicle predicted by the specific vehicle arrival prediction unit 206 for each inflow path. A vehicle group is determined based on (specific vehicle arrival information 310). Specifically, with respect to the arrival traffic flow prediction information 306 and the specific vehicle arrival information 310, the first individual vehicle group determination for determining whether or not a vehicle group exists within the determination period is performed. Repeatedly while shifting by 1 second. In the first individual vehicle group determination, in the specific vehicle arrival information 310, the presence / absence of a vehicle group within the determination period is determined based on whether or not the specific vehicle exists within the determination period, and it is determined that the vehicle group exists. In this case, the period from the first unit period in which the specific vehicle exists in the unit period within the determination period to the last unit period in which the number of arriving vehicles satisfies the predetermined number of units in the arrival traffic flow prediction information 306 is determined. The vehicle group is determined (see FIG. 2).

  The second vehicle group determination unit 212 determines a vehicle group for each inflow path based on the arrival traffic flow (arrival traffic flow prediction information 306) predicted by the arrival traffic flow prediction unit 202. Specifically, the second individual vehicle group determination for determining whether a vehicle group exists within the determination period is repeated with respect to the arrival traffic flow prediction information 306 while shifting the determination period by 1 second as a unit period. Do. In the second individual vehicle group determination, in the arrival traffic flow prediction information 306, the presence / absence of the vehicle group in the determination period depends on whether the total number of arrival vehicles in the determination period is equal to or greater than a predetermined determination threshold number. In the unit period within the determination period, from the first unit period in which the number of arriving vehicles 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. 3).

  Then, the vehicle group determination unit 208 includes a determination result of the first individual vehicle group determination by the first vehicle group determination unit 210 and a determination result of the second individual vehicle group determination by the second vehicle group determination unit 212. Are integrated to generate a vehicle group determination table 312 which is the final vehicle group determination (see FIG. 4).

  The parameter changing unit 214 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 312. 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 type of changeable parameter and the change range thereof are stored as parameter setting range information 316. In the present embodiment, the cycle length is fixed, and the split time is changed by changing the display time of the green signal (see FIG. 5).

  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 channel, the outflow availability table 322 is generated by determining whether or not to flow out for each unit period according to the signal control parameter candidate, and the arrival traffic flow prediction information 306, the vehicle group determination table 312 and the outflow availability table 322 Based on the above, calculate the number of stays per unit period. 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 the set signal control parameter 330.

  The signal control unit 216 controls the vehicle signal lamp 20 at its own intersection according to the setting signal control parameter 330 changed / set by the parameter changing unit 214.

  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 stores the 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 specific vehicle arrival information 310. Vehicle group determination table 312, current stage table 314, parameter setting range information 316, parameter candidate information 318, and setting signal control parameter 330 are stored.

  The parameter candidate information 318 is information related to the signal control parameter candidates generated by the parameter changing unit 214. For each signal control parameter candidate 320, the outflow propriety table 322, the staying number information 324, the number of stops 326, and the number of all stops 328 are stored in association with each other.

[Process flow]
FIG. 8 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). . Further, the specific vehicle arrival prediction unit 206 predicts the arrival of the specific vehicle based on the detection signal of the specific vehicle detector 30 for each inflow path, and generates the specific vehicle arrival information 310 (step S3).

  Next, the vehicle group determination unit 208 determines a vehicle group based on the arrival traffic flow prediction information 306 and the specific vehicle arrival information 310 for each inflow path, and generates a vehicle group determination table 312. That is, the first vehicle group determination unit 210 determines whether or not a specific vehicle exists within the determination period with respect to the arrival traffic flow prediction information 306 and the specific vehicle arrival information 310 for each inflow route. The first individual vehicle group determination for determining the presence / absence of the vehicle group in the section is repeated while shifting the determination period (step S5). In addition, the second vehicle group determination unit 212 determines, for each inflow route, whether the total number of arrival vehicles in the determination period is equal to or greater than a predetermined determination threshold number with respect to the arrival traffic flow prediction information 306. The second individual vehicle group determination for determining the presence / absence of the vehicle group in the section is repeatedly performed while shifting the determination period (step S7). Then, the vehicle group determination unit 208 integrates the determination result of the first individual vehicle group determination and the determination result of the second individual vehicle group determination, and the vehicle group determination table 312 which is the final vehicle group determination. Is generated (step S9).

  Subsequently, the parameter changing unit 214 changes the blue time and generates a plurality of signal control parameter candidates (step S11). 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 322 is generated (step S13). Next, based on the arrival traffic flow prediction information 306 of the target inflow path and the vehicle group determination table 312, the number of vehicles arrived is multiplied by the weight coefficient 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 324 is generated (step S15). At this time, in accordance with the outflow propriety table 322, for the unit period in which outflow is “permitted”, the number of staying 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 324 is calculated as the number of stops (step S17).

  When the process of Loop B for all the inflow paths is performed, the calculated total number of stops for each inflow path is calculated as the total number of stops at the own intersection (step S19). 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 S21). When the above processing is performed, the traffic signal control processing ends.

[Function and effect]
As described above, the traffic signal controller 10 according to the present embodiment repeats the individual vehicle group determination as to whether or not the vehicle group exists within the determination period for each inflow path at the intersection, while shifting the determination period by 1 second. The vehicle group is determined by integrating the determination results of the individual vehicle group determination. The individual vehicle group determination includes a first individual vehicle group determination based on the arrival timing of the specific vehicle and a second individual vehicle group determination based on the arrival traffic flow prediction information. Thereby, the arrival traffic flow prediction information of the own intersection is set while shifting the determination period, the existence of the vehicle group within each determination period is determined, and the determination results of each determination period are integrated to form the vehicle group A new vehicle group determination method is realized, such as determining.

  In particular, in the first individual vehicle group determination, the vehicle group can be determined based on the predicted arrival timing of the specific vehicle at its own intersection. Since the specific vehicle observes safe driving and the acceleration / deceleration tends to be gentle, the vehicle often continues behind the specific vehicle. Therefore, in the first individual vehicle group determination, the vehicle group can be determined using the specific vehicle as one guide. Further, by treating the specific vehicle as the head of the vehicle group, for example, it is possible to control the traffic signal at the intersection so that the group of vehicle groups following the specific vehicle pass preferentially.

[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) First Individual Vehicle Group Determination In the above-described embodiment, the determination period is set to be shifted by 1 second and the first individual vehicle group determination is performed (see FIG. 4). The determination period may be set only when the specific vehicle exists in the unit period, and the first individual vehicle group determination may be performed. For example, in the period of 5 to 9 seconds shown in FIG. 2B, since there is no specific vehicle in the unit period of the 5th second which is the first unit period, the determination period is not set, and the first individual Car group determination is not performed. Thereby, the processing load can be reduced.

(B) Second Individual Vehicle Group Determination Similarly, for the second individual vehicle group determination, similarly, the number of arrival vehicles in the first unit period exceeds a predetermined number condition (in the present embodiment, that is, It is also possible to set the determination period and perform the second individual vehicle group determination only when the condition is not zero. For example, in the period from the 7th to the 11th seconds shown in FIG. 3B, the number of vehicles arrived in the unit period of the 7th second, which is the first unit period, is 0 and does not satisfy the number condition. Therefore, the second individual vehicle group determination is not 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.

(C) 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. 6). 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.

(D) Signal Control Parameter Candidate In the above-described embodiment, the signal control parameter candidate 320 has been described as being generated. However, the signal control parameter candidate 320 may be stored in advance. In that case, step S11 of FIG. 8 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.

(F) Specific vehicle detector In the above-described embodiment, the specific vehicle detector 30 has been described as detecting a specific vehicle and outputting the result. Instead of the specific vehicle sensor 30, the traffic signal controller 10 replaces the specific vehicle with a sensor that outputs a two-level detection signal according to the presence / absence of a passing vehicle at the detection target position. It is good also as a structure provided with the function part which judges. The function unit obtains the vehicle length from the continuous time when the input sensing signal is present and the vehicle traveling speed, and determines that the passing vehicle is a “specific vehicle” when the vehicle length is equal to or longer than a predetermined length. You can do that.

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 Specific vehicle arrival prediction part 208 Vehicle group determination part, 210 1 vehicle group determination unit, 212 second vehicle group determination unit 214 parameter change unit, 216 signal control unit 300 storage unit 302 traffic signal control program 304 traffic flow prediction information of adjacent intersection 306 arrival traffic flow prediction information, 308 outflow Traffic flow prediction information 310 Specific vehicle arrival information, 312 vehicle group determination table 314 Current floor table, 316 Parameter setting range information,
318 Parameter candidate information 320 Signal control parameter candidate, 322 Outflow possibility table 324 Number of staying units, 326 Number of stops, 328 Total number of stops 330 Setting signal control parameter 20 Signal lamp 30 for vehicle 30 Specific vehicle detector

Claims (5)

A traffic signal controller for controlling traffic signals using given signal control parameters,
A specific vehicle arrival prediction unit that predicts a predicted arrival timing of the specific vehicle at the self-intersection using a detection result of a specific vehicle detector that detects a specific vehicle that is a medium-sized vehicle or a large vehicle flowing into the self-intersection;
Based on the predicted arrival traffic flow information indicating the predicted number of arrivals in time series to the own intersection, a first continuous time range in which the vehicle may arrive following the predicted arrival timing is determined as the position where the vehicle group exists. A vehicle group determination unit;
A parameter changing unit that changes the signal control parameter using the presence position of the vehicle group;
Traffic signal control machine equipped with. The first vehicle group determination unit determines the possibility of arrival of the vehicle for each unit period, and the range of consecutive unit periods in which the vehicle may arrive following the unit period corresponding to the predicted arrival timing. Is determined as the continuous time range,
The traffic signal controller according to claim 1. A second vehicle group determination unit that determines the presence of a vehicle group within each determination period by shifting the determination period for a predetermined time with respect to the predicted arrival traffic flow information;
An integration unit that integrates the determination result of the first vehicle group determination unit and the determination result of the second vehicle group determination unit;
The traffic signal controller according to claim 1, further comprising: The determination period is a period of 3 seconds to 10 seconds,
The traffic signal controller according to claim 3. A prediction unit for obtaining information on outflow traffic flow from a neighboring intersection and predicting the arrival prediction traffic flow information;
The traffic signal controller according to claim 1, further comprising:

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