WO2024252808A1 - Traffic information processing device, offset design system, traffic information processing method, and traffic information processing program - Google Patents

Abstract

This traffic information processing device is provided with: an acquisition unit that acquires probe information indicating measurement results regarding vehicle travel; and a processing unit that performs calculation processing to design an offset of a traffic signal provided at an intersection, on the basis of the probe information acquired by the acquisition unit.

Description

Traffic information processing device, offset design system, traffic information processing method, and traffic information processing program

The present disclosure relates to a traffic information processing device, an offset design system, a traffic information processing method, and a traffic information processing program.
This application claims priority based on Japanese Patent Application No. 2023-94532, filed on June 8, 2023, the disclosure of which is incorporated herein in its entirety.

Patent Document 1 (WO 2020/071040) describes the following calculation device. That is, the calculation device is a device that calculates traffic indices necessary for calculating signal control parameters, and includes a first calculation unit that calculates normalized data that expresses the traffic variable of the entrance road of a target intersection as a ratio to a saturation traffic flow rate, and a second calculation unit that uses the normalized data to calculate the traffic index defined by an equation in which the traffic variable of the entrance road is included in the numerator and the saturation traffic flow rate is included in the denominator.

International Publication No. 2020/071040

The traffic information processing device disclosed herein includes an acquisition unit that acquires probe information indicating measurement results related to vehicle travel, and a processing unit that performs calculations to design the offset of a traffic signal installed at an intersection based on the probe information acquired by the acquisition unit.

One aspect of the present disclosure can be realized not only as a traffic information processing device equipped with such a characteristic processing unit, but also as a semiconductor integrated circuit that realizes part or all of the traffic information processing device.

FIG. 1 is a diagram showing a configuration of an offset setting system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating a configuration of a traffic information processing device according to an embodiment of the present disclosure. FIG. 3 is a diagram showing a traffic situation at an intersection in the offset setting system according to the embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a method for determining an offset by an offset determination unit in a traffic information processing device according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a simulation result by the offset determination unit in the traffic information processing device according to the embodiment of the present disclosure. FIG. 6 is a flowchart defining an example of an operation procedure when the traffic information processing device according to the embodiment of the present disclosure determines an offset.

Technology has been developed to calculate signal control parameters used for remote control of traffic signals installed at intersections.

[Problem to be solved by the present disclosure]
Conventionally, traffic signal offsets are designed using intersection parameters calculated based on the detection results of vehicle detectors installed at the intersection. However, in some areas, there are many intersections where vehicle detectors are not installed. Therefore, a technology that can design an appropriate offset for a traffic signal at an intersection where vehicle detectors are not installed is desired.

The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a traffic information processing device, an offset design system, a traffic information processing method, and a traffic information processing program that are capable of designing an appropriate offset for a traffic signal at an intersection where no vehicle detector is installed.

[Effects of the present disclosure]
According to the present disclosure, it is possible to design an appropriate offset for a traffic signal at an intersection where vehicle detectors are not installed.

[Description of the embodiments of the present disclosure]
First, the contents of the embodiments of the present disclosure will be listed and described.

(1) A traffic information processing device according to an embodiment of the present disclosure includes an acquisition unit that acquires probe information indicating measurement results related to vehicle travel, and a processing unit that performs calculations to design the offset of a traffic signal installed at an intersection based on the probe information acquired by the acquisition unit.

In this way, by performing calculation processing to design the offset based on the probe information, it is possible to design the offset of a traffic signal without using the detection results of a vehicle detector. Therefore, it is possible to design an appropriate offset for a traffic signal at an intersection where no vehicle detectors are installed.

(2) In the above (1), the processing unit may perform the following arithmetic processing: calculate an actual value of delay time due to waiting at a traffic light per vehicle based on the probe information, obtain a relationship between the traffic volume at the intersection and the saturation traffic flow rate at the intersection based on the calculated actual value, and determine a combination of the traffic volume and the saturation traffic flow rate that satisfies the relationship as the parameter of the intersection; and determine the offset using the determined parameters.

If the combination of traffic volume and saturation traffic flow rate satisfies the relationship derived from the probe information, the delay time caused by a vehicle waiting at a traffic light will be the same regardless of the individual values of the traffic volume and saturation traffic flow rate. With the above configuration, instead of the traffic volume and saturation traffic flow rate calculated based on the detection results of the vehicle detector, any combination of traffic volume and saturation traffic flow rate that satisfies the relationship can be used as a parameter to determine the offset.

(3) In the above (2), the processing unit may calculate multiple delay times per vehicle due to waiting at traffic lights when the provisional setting value of the offset is changed, and determine the provisional setting value corresponding to the smallest delay time among the multiple delay times as the offset.

This configuration makes it possible to design an optimal offset based on the delay time each vehicle experiences while waiting at traffic lights.

(4) In the above (2) or (3), the processing unit may determine the offsets of the multiple traffic signals provided at the multiple intersections, respectively, using the parameters of the most important intersection among the multiple intersections, or an intersection upstream of the multiple intersections.

This configuration allows the offsets for multiple traffic signals to be designed using the parameters of one intersection, making it possible to determine the offsets with simpler processing than with a configuration that uses parameters for multiple intersections.

(5) The offset design system according to an embodiment of the present disclosure includes a traffic information processing device and a traffic signal installed at an intersection, and the traffic information processing device acquires probe information indicating measurement results related to vehicle travel, and performs calculations to design the offset of the traffic signal based on the acquired probe information.

In this way, by performing calculation processing to design the offset based on the probe information, it is possible to design the offset of a traffic signal without using the detection results of a vehicle detector. Therefore, it is possible to design an appropriate offset for a traffic signal at an intersection where no vehicle detectors are installed.

(6) A traffic information processing method according to an embodiment of the present disclosure is a traffic information processing method in a traffic information processing device, and includes a step of acquiring probe information indicating measurement results related to vehicle travel, and a step of performing a calculation process for designing an offset for a traffic signal installed at an intersection based on the acquired probe information.

In this way, by performing calculations to design offsets based on probe information, it is possible to design the offsets of traffic signals without using the detection results of vehicle detectors. Therefore, it is possible to design appropriate offsets for traffic signals at intersections where vehicle detectors are not installed.

(7) A traffic information processing program according to an embodiment of the present disclosure is a traffic information processing program used in a traffic information processing device, and is a program for causing a computer to function as an acquisition unit that acquires probe information indicating measurement results related to vehicle travel, and a processing unit that performs calculation processing to design the offset of a traffic signal installed at an intersection based on the probe information acquired by the acquisition unit.

In this way, by performing calculation processing to design the offset based on the probe information, it is possible to design the offset of a traffic signal without using the detection results of a vehicle detector. Therefore, it is possible to design an appropriate offset for a traffic signal at an intersection where no vehicle detectors are installed.

Below, embodiments of the present disclosure will be described with reference to the drawings. Note that the same or equivalent parts in the drawings will be given the same reference numerals and their description will not be repeated. In addition, at least some of the embodiments described below may be combined in any manner.

[Configuration and basic operation]
Fig. 1 is a diagram showing a configuration of an offset setting system according to an embodiment of the present disclosure. Referring to Fig. 1, an offset setting system 201 includes a probe vehicle 1, traffic signals 21A, 21B, 21C, and 21D that are traffic signals 21, and a traffic information processing device 101. The probe vehicle 1 travels on a road 41. Fig. 1 representatively shows one lane on the road 41 on which the probe vehicle 1 travels, but the road 41 may have two or more lanes.

On the road 41, intersections 31A, 31B, 31C, and 31D are provided in this order along the traveling direction of the probe vehicle 1. Traffic signals 21A, 21B, 21C, and 21D are provided at the intersections 31A, 31B, 31C, and 31D, respectively. For example, no vehicle detectors are provided at the intersections 31A, 31B, 31C, and 31D. Hereinafter, the road section between the intersection 31A and an intersection 31 (not shown) adjacent to the upstream side of the intersection 31A is also referred to as link Sa. The road section between the intersections 31A and 31B is also referred to as link Sb, the road section between the intersections 31B and 31C is also referred to as link Sc, and the road section between the intersections 31C and 31D is also referred to as link Sd. Each of the links Sa, Sb, Sc, and Sd is also referred to as link S.

The probe vehicle 1 is equipped with an on-board device 2. The on-board device 2 is capable of communicating with the traffic information processing device 101 via a wireless base station 111 and a network 121. The on-board device 2 generates probe information indicating measurement results related to the traveling of the probe vehicle 1 equipped with the on-board device 2, and transmits the generated probe information to the traffic information processing device 101 via the wireless base station 111 and the network 121.

More specifically, the vehicle-mounted device 2 receives GPS signals from multiple GPS (Global Positioning System) satellites and detects the current position and speed of the probe vehicle 1 based on the received GPS signals. The vehicle-mounted device 2 detects the current position and speed of the probe vehicle 1 at a timing according to a predetermined detection period and stores the detection results and vehicle data indicating the detection time in a storage unit (not shown). The vehicle-mounted device 2 periodically or irregularly acquires multiple vehicle data from the storage unit, generates probe information including the acquired multiple vehicle data and the ID of the vehicle-mounted device 2, and transmits the generated probe information to the traffic information processing device 101 via the wireless base station 111 and the network 121.

The traffic information processing device 101 determines the offsets of the traffic signals 21B, 21C, and 21D. For example, in response to a request from a user of the traffic information processing device 101, it determines the optimal offsets of the traffic signals 21B, 21C, and 21D and presents the determined offsets to the user.

Here, the offset is the deviation from a certain point in time of the signal display, and is expressed as a percentage of time or period. For example, the offset is the deviation of the start of the green signal from a reference point common to traffic signals 21. In the following, the offset is taken to be an absolute offset, meaning the deviation of the start of the green signal from the start of the green signal of traffic signal 21A. Note that the offset may also be the deviation of the start points of the same display between adjacent intersections, i.e., a relative offset.

[assignment]
A technique that can design appropriate offsets for traffic signals at intersections that do not have vehicle detectors is desirable.

More specifically, in the past, it was thought that in order to design the optimal offset for a traffic signal, it was necessary to use the detection results from vehicle detectors installed at the intersection. Specifically, in conventional offset design methods, the traffic volume Vin at an intersection and the saturation traffic flow rate Sf at that intersection are calculated based on the detection results from the vehicle detectors, and the offset for the traffic signal installed at that intersection is determined using the calculated traffic volume Vin and saturation traffic flow rate Sf.

However, in some areas, there are many intersections where vehicle detectors are not installed. Therefore, the traffic information processing device 101 according to the embodiment of the present disclosure solves the above problem by adopting the following configuration.

<Traffic information processing device>
2 is a diagram showing a configuration of a traffic information processing device according to an embodiment of the present disclosure. Referring to FIG. 2, the traffic information processing device 101 includes a receiving unit 11, a processing unit 10, and a storage unit 14. The processing unit 10 includes a parameter determining unit 12A and an offset determining unit 12B. The receiving unit 11 is an example of an acquisition unit. The receiving unit 11 and a part or the whole of the processing unit 10 are realized, for example, by a processing circuit including one or more processors. The storage unit 14 is, for example, a non-volatile memory included in the processing circuit.

The memory unit 14 stores road information and the initial offset value IV of each traffic signal 21. The road information includes the position information of the intersection 31 and the speed limit information of the road 41.

(Receiving section)
The receiver 11 acquires traffic light information indicating a cycle length C and a red time R of each traffic light 21. The cycle length C is equal to the sum of the red time R and the green time G.

Here, "cycle length C" refers to the time required for one cycle of the traffic signal 21 to go around. In other words, the cycle length C of the traffic signal 21 is the time from when the traffic signal 21 starts to light green to when the next green light starts. Note that the cycle length C of the traffic signal 21 may also be the time from when the traffic signal 21 starts to light red to when the next red light starts.

Furthermore, "red time R" refers to the time period during which vehicles do not have the right of way at the intersection 31. The start of red time R is when the green light is turned off, and the end of red time R is when the green light is turned on. Note that the start of red time R may also be when the yellow light is turned off, or when the right turn arrow light is turned off.

Furthermore, "green time G" refers to the time period during which vehicles have the right of way at intersection 31. The start of green time G is when the green light is turned on, and the end of green time G is when the green light is turned off. Note that the end of green time G may also be when the yellow light is turned off, or when the right turn arrow light is turned off.

For example, the receiving unit 11 receives traffic light information of the traffic signal 21 from a control device (not shown) in the traffic control center via the network 121. The receiving unit 11 stores the received traffic light information in the storage unit 14. Note that the receiving unit 11 may accept traffic light information from a user of the traffic information processing device 101 instead of receiving traffic light information from a control device in the traffic control center.

The receiver 11 acquires probe information that indicates measurement results regarding the traveling of the probe vehicle 1. More specifically, the receiver 11 receives the probe information from the in-vehicle device 2 via the wireless base station 111 and the network 121. The receiver 11 stores the received probe information in the memory unit 14.

(Processing section)
The processing unit 10 performs calculation processing to design the offset of a traffic signal provided at an intersection, based on the probe information acquired by the receiving unit 11 .

(Process for determining parameter PMT)
As a calculation process, the parameter determination unit 12A performs a process of determining a parameter PMT of the intersection 31 based on the probe information in order to design an offset of the traffic signal 21. More specifically, when a plurality of pieces of probe information for a predetermined length of collection period are stored in the storage unit 14 by the receiving unit 11, the parameter determination unit 12A acquires the plurality of pieces of probe information from the storage unit 14, and determines a parameter PMT for each intersection 31 based on the acquired probe information. Details of the process of determining the parameter PMT will be described below.

(1) Calculation of delay time dav_pr The parameter determination unit 12A calculates the delay time dav_pr, which is the actual value of the delay time dav due to waiting at traffic lights per vehicle, based on the probe information. More specifically, the parameter determination unit 12A calculates the average travel time Tt [seconds] when the probe vehicle 1 travels along the link S, based on the probe information of multiple probe vehicles 1. Then, the parameter determination unit 12A calculates the delay time dav_pr by subtracting the travel time [seconds] when the probe vehicle 1 travels along the link S without waiting at traffic lights from the calculated average travel time Tt.

More specifically, the parameter determination unit 12A calculates the delay time dav_pr based on the road information in the storage unit 14, in accordance with the following equation (1).
dav_pr=Tt-{L/(Ve/3.6)}...(1)

In formula (1), L is the length of link S [m]. Ve is the speed limit for link S [km/h].

1 again, the parameter determination unit 12A calculates the delay time dav_pr for each intersection 31. More specifically, the parameter determination unit 12A calculates the delay time dav_prA, which is the delay time dav_pr for the intersection 31A, according to the following equation (2).
dav_prA=Tta-{La/(Vea/3.6)}...(2)

In equation (2), Tta is the average travel time Tt of link Sa. La is the length of link Sa [m]. Vea is the speed limit of link Sa [km/h].

In addition, the parameter determination unit 12A calculates a delay time dav_prB, which is the delay time dav_pr for the intersection 31B, in accordance with the following equation (3).
dav_prB=Ttb-{Lb/(Veb/3.6)}...(3)

In equation (3), Ttb is the average travel time Tt of link Sb. Lb is the length [m] of link Sb. Veb is the regulated speed [km/h] of link Sb.

In addition, the parameter determination unit 12A calculates a delay time dav_prC, which is the delay time dav_pr for the intersection 31C, in accordance with the following equation (4).
dav_prC=Ttc-{Lc/(Vec/3.6)}...(4)

In equation (4), Ttc is the average travel time Tt of link Sc. Lc is the length [m] of link Sc. Vec is the speed limit [km/h] of link Sc.

In addition, the parameter determination unit 12A calculates a delay time dav_prD, which is the delay time dav_pr for the intersection 31D, in accordance with the following equation (5).
dav_prD=Ttd-{Ld/(Ved/3.6)}...(5)

In equation (5), Ttd is the average travel time Tt of link Sd. Ld is the length [m] of link Sd. Ved is the speed limit [km/h] of link Sd.

(2) Determination of parameter PMT The parameter determination unit 12A determines the relationship between the traffic volume Vin at the intersection 31 and the saturation traffic flow rate Sf at the intersection 31 based on the calculated delay time dav_pr, and determines the combination of traffic volume Vin and saturation traffic flow rate Sf that satisfies the relationship as the parameter PMT.

Here, "traffic volume Vin" is the number of passing vehicles per unit time. Unless otherwise specified, traffic volume Vin is expressed as the number of passing vehicles per hour, but for control and evaluation purposes, traffic volume Vin for a short period of time, such as 5 or 15 minutes, may be used. Generally, traffic volume Vin increases according to traffic demand, but conversely decreases when traffic demand exceeds traffic capacity.

The "saturation traffic flow rate Sf" is expressed as the flow rate at which the second or third or subsequent vehicles pass the stop line after the traffic signal 21 turns green when there is a sufficiently long queue at the entrance to the intersection 31. In other words, the saturation traffic flow rate Sf is the maximum number of vehicles that can pass the stop line per lane per unit time at the entrance to the intersection 31 when there is sufficient traffic demand. The value of the saturation traffic flow rate Sf differs depending on the presence or absence of a dedicated right-turn lane, the presence or absence of a dedicated left-turn lane, the lane width, etc.

As described in Patent Document 1, the relationship between the traffic volume Vin and the saturation flow rate Sf is expressed by the following equations (6) and (7) using a coefficient α.
Vin=α×Sf...(6)
α={1-(R^2)/(2×dav_pr×C)}...(7)

Here, "a^b" means a to the power b. After calculating the delay time dav_pr, the parameter determination unit 12A calculates the coefficient α according to equation (7) based on the calculated delay time dav_pr and the traffic light information in the memory unit 14.

FIG. 3 is a diagram showing the traffic conditions at an intersection in an offset setting system according to an embodiment of the present disclosure. FIG. 3 shows the traffic conditions at intersection 31A when multiple stopped vehicles are assumed to stop overlapping at the same position just before the stop line of intersection 31A. In FIG. 3, the horizontal axis is time, and the vertical axis is the number of vehicles stopped at the stop line of intersection 31A. "D" in FIG. 3 shows the total delay time of the vehicle queue in one cycle of the traffic signal 21 at intersection 31A. Also, "Gc" in FIG. 3 shows the elapsed time from when the traffic signal 21 at intersection 31A starts to turn green until the last vehicle among the multiple stopped vehicles passes the stop line of intersection 31A.

Referring to Figure 3, if we assume that the number of vehicles that enter intersection 31 after the traffic signal 21 at intersection 31A starts to turn red is equal to the number of vehicles that have exited intersection 31A by time Gc, time Gc can be expressed by the following equation (8).
Gc=Vin×R/(Sf-Vin)...(8)

Moreover, the total delay time D is expressed by the following equation (9).
D=0.5×(R+Gc)×R×Vin...(9)

The delay time dav per vehicle due to waiting at a traffic light is expressed by the following equation (10).
dav=D/(C×Vin)...(10)

For example, the offset of the traffic signal 21 is set to a value that minimizes the delay time dav. As is clear from the above equations (8), (9), and (10), if the combination of traffic volume Vin and saturation traffic flow rate Sf satisfies equation (6), the delay time dav for intersection 31A will be the same regardless of the individual values of traffic volume Vin and saturation traffic flow rate Sf. Similarly, if the combination of traffic volume Vin and saturation traffic flow rate Sf satisfies equation (6), the delay time dav for intersections 31B, 31C, and 31D will be the same regardless of the individual values of traffic volume Vin and saturation traffic flow rate Sf.

Therefore, the parameter determination unit 12A calculates the coefficient α according to equation (7) and determines any combination of the traffic volume Vin and the saturation traffic flow rate Sf that satisfies equation (6) as the parameter PMT for designing the offset of the traffic signal 21.

More specifically, the parameter determination unit 12A calculates a coefficient α for each intersection 31 based on the delay time dav_pr for each intersection 31, and determines a parameter PMT for each intersection 31 based on the calculated coefficient α and equation (6). The parameter determination unit 12A outputs the determined parameter PMT to the offset determination unit 12B.

(Process for determining offset)
The offset determination unit 12B performs a process of determining an offset using the parameter PMT determined by the parameter determination unit 12A as a calculation process.

FIG. 4 is a diagram showing an example of a method for determining an offset by an offset determination unit in a traffic information processing device according to an embodiment of the present disclosure. In FIG. 4, the horizontal axis is distance, and the vertical axis is time. "Ra, Rb, Rc, Rd" in FIG. 4 indicate the red time R of traffic signals 21A, 21B, 21C, and 21D, respectively. Also, "IVb, IVc, IVd" in FIG. 4 indicate the initial offset value IV of traffic signals 21B, 21C, and 21D, respectively. Also, Vina, Vinb, Vinc, and Vind in FIG. 4 indicate the traffic volume Vin of traffic signals 21A, 21B, 21C, and 21D, respectively. Also, "Sfa, Sfb, Sfc, and Sfd" in FIG. 4 indicate the saturated traffic flow rate Sf of traffic signals 21A, 21B, 21C, and 21D, respectively.

Referring to FIG. 4, the offset determination unit 12B simulates vehicle travel using as input parameters Pin the red time R and green time G of each intersection 31, the initial offset value IV of traffic signals 21B, 21C, and 21D, the lengths Lb, Lc, and Ld of links Sb, Sc, and Sd, the vehicle travel speed DS, and a combination of traffic volume Vin and saturation traffic flow rate Sf determined as parameters PMT of each intersection 31. For example, the offset determination unit 12B uses the regulated speed Ve as the travel speed DS. The offset determination unit 12B determines the offsets of traffic signals 21B, 21C, and 21D based on the simulation results.

For example, the offset determination unit 12B uses the input parameter Pin to detect the offset of the traffic signals 21B, 21C, and 21D when the delay time dav due to waiting at the traffic light per vehicle passing through the intersections 31A, 31B, 31C, and 31D is minimized according to the hill climbing method used in TRANSYT-7F and the like.

FIG. 5 is a diagram showing an example of the simulation results by the offset determination unit in the traffic information processing device according to the embodiment of the present disclosure. In FIG. 5, the horizontal axis is distance, and the vertical axis is time. The arrows in FIG. 5 indicate the travel trajectory of the vehicle. Also, "Da, Db, Dc, Dd" in FIG. 5 indicate the total delay time D at intersections 31A, 31B, 31C, and 31D, respectively.

Referring to FIG. 5, the offset determination unit 12B calculates multiple delay times dav when the provisional offset values of the traffic signals 21B, 21C, and 21D are changed, and determines the provisional offset value corresponding to the smallest delay time dav among the multiple delay times dav.

More specifically, the offset determination unit 12B uses the input parameter Pin to simulate vehicle travel while varying a set of provisional offset values for the traffic signals 21B, 21C, and 21D according to a predetermined algorithm based on the initial value IV, thereby calculating multiple delay times dav corresponding to each of the multiple sets of provisional offset values. The offset determination unit 12B then determines the set of provisional offset values that results in the smallest calculated delay time dav as the offset for the traffic signals 21B, 21C, and 21D.

The offset determination unit 12B notifies the user of the traffic information processing device 101 of the determined offsets for traffic signals 21B, 21C, and 21D.

The offset determination unit 12B may determine the offsets of the traffic signals 21B, 21C, and 21D using the parameter PMT of the most important intersection 31 among the intersections 31. More specifically, when the most important intersection 31 is intersection 31C, the offset determination unit 12B simulates vehicle travel using the parameter PMT of intersection 31C as the parameter PMT of each intersection 31, and determines the offsets of the traffic signals 21B, 21C, and 21D based on the simulation results.

The offset determination unit 12B may also determine the offsets of the traffic signals 21B, 21C, and 21D using the parameter PMT of the intersection 31A upstream of the intersections 31B, 31C, and 31D. More specifically, the offset determination unit 12B simulates vehicle travel using the parameter PMT of the intersection 31A as the parameter PMT of each intersection 31, and determines the offsets of the traffic signals 21B, 21C, and 21D based on the simulation results.

[Operation flow]
FIG. 6 is a flowchart defining an example of an operation procedure when the traffic information processing device according to the embodiment of the present disclosure determines an offset.

Referring to FIG. 6, first, the traffic information processing device 101 receives traffic light information indicating the cycle length C and red time R of each traffic light 21 from a control device (not shown) in the traffic control center (step S11).

Next, the traffic information processing device 101 receives probe information from the vehicle-mounted device 2 (step S12).

Next, the traffic information processing device 101 calculates the delay time dav_pr, which is the actual value of the delay time dav due to waiting at traffic lights per vehicle, based on the probe information (step S13).

Next, the traffic information processing device 101 obtains the relationship between the traffic volume Vin at the intersection 31 and the saturation traffic flow rate Sf at the intersection 31 based on the delay time dav_pr. More specifically, the traffic information processing device 101 calculates the coefficient α shown in the above-mentioned formula (7) based on the delay time dav_pr (step S14).

Next, the traffic information processing device 101 determines a combination of traffic volume Vin and saturation traffic flow rate Sf that satisfies the relationship between traffic volume Vin and saturation traffic flow rate Sf as parameter PMT. More specifically, the traffic information processing device 101 determines an arbitrary combination of traffic volume Vin and saturation traffic flow rate Sf that satisfies formula (6) as parameter PMT (step S15).

Then, the traffic information processing device 101 uses the parameters PMT to determine the offsets of the traffic signals 21B, 21C, and 21D. More specifically, the traffic information processing device 101 simulates vehicle travel using the red time R and green time G of each intersection 31, the initial offset value IV of the traffic signals 21B, 21C, and 21D, the lengths Lb, Lc, and Ld of the links Sb, Sc, and Sd, the vehicle travel speed DS, and a combination of the traffic volume Vin and saturation traffic flow rate Sf determined as the parameters PMT of each intersection 31 as input parameters Pin. The traffic information processing device 101 then determines the offsets of the traffic signals 21B, 21C, and 21D based on the simulation results (step S16).

The traffic information processing device 101 notifies the user of the traffic information processing device 101 of the determined offsets for traffic signals 21B, 21C, and 21D (step S17).

In the traffic information processing device 101 according to the embodiment of the present disclosure, the processing unit 10 is configured to include the parameter determination unit 12A, but this is not limited to the above. The processing unit 10 may be configured not to include the parameter determination unit 12A. In this case, the offset determination unit 12B determines the offset based on the probe information without using the parameter PMT.

In addition, in the traffic information processing device 101 according to the embodiment of the present disclosure, the processing unit 10 is configured to include the offset determination unit 12B, but this is not limited to the above. The processing unit 10 may be configured not to include the offset determination unit 12B. In this case, the parameter determination unit 12A may output the determined parameter PMT to an external device outside the traffic information processing device 101, or may notify the user of the traffic information processing device 101. The external device determines the offset using the parameter PMT determined in the traffic information processing device 101. The user designs the offset using the parameter PMT determined in the traffic information processing device 101.

In addition, in the traffic information processing device 101 according to the embodiment of the present disclosure, the offset determination unit 12B is configured to calculate multiple delay times dav when the provisional offset values of the traffic signals 21B, 21C, and 21D are changed, and to determine as the offset the provisional setting value corresponding to the smallest delay time dav among the multiple delay times dav, but this is not limited to this. Instead of the delay time dav, the offset determination unit 12B may be configured to calculate multiple numbers of times the vehicle stops due to signals, and to determine as the offset the provisional setting value corresponding to the smallest number of times the vehicle stops among the multiple numbers of times the vehicle stops.

In addition, in the traffic information processing device 101 according to the embodiment of the present disclosure, the parameter determination unit 12A is configured to determine any combination of traffic volume Vin and saturation traffic flow rate Sf that satisfies the above-mentioned formula (6) and formula (7) as the parameter PMT, but this is not limited to this. The parameter determination unit 12A may be configured to determine, as the parameter PMT, a combination of traffic volume Vin and saturation traffic flow rate Sf that satisfies a formula other than formula (6) and formula (7) as the relationship between the traffic volume Vin and the saturation traffic flow rate Sf. In addition, the parameter determination unit 12A may be configured to determine, as the parameter PMT, an index value related to the intersection 31 other than the combination of traffic volume Vin and saturation traffic flow rate Sf.

In addition, in the traffic information processing device 101 according to the embodiment of the present disclosure, the receiving unit 11 is configured to receive probe information from the in-vehicle device 2, but this is not limited to the above. The receiving unit 11 may be configured to receive probe information from a communication device such as a smartphone in the vehicle instead of the in-vehicle device 2.

In addition, in the offset setting system 201 according to the embodiment of the present disclosure, the intersections 31A, 31B, 31C, and 31D are configured such that no vehicle detectors are provided, but this is not limited to the configuration. Vehicle detectors may be provided at the intersections 31A, 31B, 31C, and 31D. In other words, the traffic information processing device 101 may determine parameters for an intersection 31 that has a vehicle detector, and use the parameters to determine the offset of the traffic signal 21 at that intersection 31.

The above-described embodiments should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

Each process (each function) in the above-mentioned embodiments is realized by a processing circuit (circuitry) including one or more processors. The above-mentioned processing circuit may be composed of an integrated circuit or the like that combines one or more memories, various analog circuits, and various digital circuits in addition to the one or more processors. The one or more memories store programs (instructions) that cause the one or more processors to execute each of the above processes. The one or more processors may execute each of the above processes according to the programs read from the one or more memories, or may execute each of the above processes according to a logic circuit designed in advance to execute each of the above processes. The processor may be any of various processors suitable for computer control, such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit). The physically separated processors may cooperate with each other to execute the above processes. For example, the processors mounted on each of the physically separated computers may cooperate with each other via a network such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet to execute the above processes. The above program may be installed into the memory from an external server device or the like via the network, or may be distributed in a state stored on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory), or semiconductor memory, and installed into the memory from the recording medium.

The above description includes the following additional features.
[Appendix 1]
an acquisition unit that acquires probe information indicating measurement results related to vehicle travel;
a determination unit that determines the parameters of the intersection for designing an offset of a traffic signal provided at the intersection based on the probe information acquired by the acquisition unit,
The determination unit calculates an actual value of a delay time due to waiting at a traffic light per vehicle based on the probe information,
the determination unit determines a relationship between the traffic volume and the saturation flow rate, which is represented by equations (A) and (B), where Vin is the traffic volume at the intersection, Sf is the saturation flow rate at the intersection, R is the red time of the traffic signal, C is a cycle length of the traffic signal, and dav_pr is the actual value;
Vin=α×Sf...(A)
α={1-(R^2)/(2×dav_pr×C)}...(B)
The traffic information processing device, wherein the determination unit determines, as the parameter, a combination of the traffic volume and the saturation traffic flow rate that satisfies the formula (A) and the formula (B).

[Appendix 2]
A traffic information processing device,
A processing circuit is provided,
The processing circuitry includes:
Acquire probe information indicating measurement results regarding vehicle travel;
A traffic information processing device that performs calculation processing to design offsets for traffic signals installed at intersections based on the acquired probe information.

REFERENCE SIGNS LIST 1 probe vehicle 2 on-board device 10 processing unit 11 receiving unit 12A parameter determination unit 12B offset determination unit 14 storage unit 21, 21A, 21B, 21C, 21D traffic signal 31, 31A, 31B, 31C, 31D intersection 41 road 101 traffic information processing device 111 wireless base station 121 network 201 offset design system S, Sa, Sb, Sc, Sd link Gc elapsed time D, Da, Db, Dc, Dd total delay time R, Ra, Rb, Rc, Rd red time L, Lb, Lc, Ld length IV, IVb, IVc, IVd initial value Vin, Vina, Vinb, Vinc, Vind traffic volume Sf, Sfa, Sfb, Sfc, Sfd Saturation traffic flow rate

Claims (7)

an acquisition unit that acquires probe information indicating measurement results related to vehicle travel;
a processing unit that performs calculation processing to design an offset of a traffic signal provided at an intersection based on the probe information acquired by the acquisition unit. The traffic information processing device according to claim 1, wherein the processing unit performs the following operations as the arithmetic process: calculating an actual value of delay time due to waiting at a traffic light per vehicle based on the probe information, determining a relationship between the traffic volume at the intersection and the saturation traffic flow rate at the intersection based on the calculated actual value, and determining a combination of the traffic volume and the saturation traffic flow rate that satisfies the relationship as a parameter of the intersection; and determining the offset using the determined parameters. The traffic information processing device according to claim 2, wherein the processing unit calculates multiple delay times per vehicle due to waiting at traffic lights when the provisional setting value of the offset is changed, and determines, as the offset, the provisional setting value corresponding to the smallest delay time among the multiple delay times. The traffic information processing device according to claim 2 or 3, wherein the processing unit determines the offsets of the multiple traffic signals provided at the multiple intersections, respectively, using the parameters of the most important intersection among the multiple intersections, or the intersection upstream of the multiple intersections. A traffic information processing device;
A traffic signal is provided at the intersection.
The traffic information processing device acquires probe information indicating measurement results regarding vehicle travel, and performs calculations to design the offset of the traffic signal based on the acquired probe information. A traffic information processing method in a traffic information processing device, comprising:
acquiring probe information indicating measurement results relating to vehicle travel;
and performing a calculation process for designing an offset of a traffic signal provided at an intersection based on the acquired probe information. A traffic information processing program for use in a traffic information processing device,
Computer,
an acquisition unit that acquires probe information indicating measurement results related to vehicle travel;
a processing unit that performs a calculation process for designing an offset of a traffic signal provided at an intersection based on the probe information acquired by the acquisition unit;
A traffic information processing program that functions as a

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