JP2017049951A - Traffic information provision device, computer program, and traffic information provision method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traffic information provision device, a computer program, and a traffic information provision method capable of providing traffic information in a predetermined section of a road.SOLUTION: A traffic information provision device includes: a traffic amount acquisition section for acquiring spot traffic amounts of an upstream spot and a downstream spot where respective vehicle sensors are arranged at an arbitrary point of time on the basis of sensing data obtained by the respective vehicle sensors; an in/out path traffic amount calculation section for calculating in/out path traffic amounts of a flow-in path and a flow-out path in a section at an arbitrary point of time on the basis of the spot traffic amounts of the upstream spot and the downstream spot acquired over a predetermined time; a probe information acquisition section for acquiring probe information of vehicles traveling in the section; and a section vehicle number estimation section for estimating the number of section vehicles existing in a section at an arbitrary point of time on the basis of the acquired spot traffic amounts, the calculated in/out path traffic amounts, and the acquired probe information.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a traffic information providing apparatus that provides traffic information in a predetermined section of a road, a computer program for realizing the traffic information providing apparatus, and a traffic information providing method.

  Conventionally, on highways and the like, traffic information such as travel time between interchanges (between ICs) or traffic jam information is provided. For example, traffic information is provided by calculating the average speed of a vehicle using sensing data obtained by a vehicle detector installed on a road. On heavy traffic routes in metropolitan areas where the occurrence frequency of traffic congestion is relatively high, for example, vehicle detectors are installed at intervals of 500 m (city highway) to 2 km (intercity highway). In such heavy traffic routes in metropolitan areas, the average spatial speed between interchanges can be obtained accurately, and traffic information such as accurate travel time or traffic jam information is displayed on information boards, highway radios, VICS ( It is provided to the driver through various information providing media such as a registered trademark.

  On the other hand, on highways other than metropolitan areas where the occurrence frequency of traffic congestion is relatively low, the number of vehicle detectors installed is small. For example, only one place is installed in an interchange section of about 15 km. For this reason, when a traffic jam occurs on such a highway, it is difficult to provide accurate travel time or traffic jam information.

  In order to solve such a problem, instead of using a vehicle detector, travel time is calculated by using probe information such as the position of the vehicle, identification information, and reception time of the identification information transmitted by the in-vehicle device. A calculation device is disclosed (see Patent Document 1).

Japanese Patent No. 4283809

  However, the proportion of vehicles equipped with in-vehicle devices that can transmit probe information is relatively small. For this reason, it is difficult to acquire the amount of probe information necessary to provide traffic information. For this reason, it has been desired to provide accurate traffic information even when the installation density of vehicle detectors is low and the probe information acquisition frequency is low.

  The present invention has been made in view of such circumstances, a traffic information providing apparatus capable of providing traffic information in a predetermined section of a road, a computer program for realizing the traffic information providing apparatus, and traffic information An object is to provide a providing method.

  A traffic information providing apparatus according to an embodiment of the present invention is a traffic information providing apparatus that provides traffic information in a section defined by two vehicle sensors provided on a road, and is obtained by each vehicle sensor. A traffic volume acquisition unit for acquiring a point traffic volume at an arbitrary point of the upstream point and the downstream point provided with each vehicle sensor based on the detected data, and the traffic volume acquisition unit for a predetermined time Based on the acquired traffic volume at the upstream and downstream points, the input / output traffic volume calculation unit for calculating the input / output traffic volume of the inflow and outflow routes in the section, and probe information of the vehicle that has traveled in the section Based on the probe information acquisition unit, the point traffic acquired by the traffic acquisition unit, the input / output traffic calculated by the input / output traffic calculation unit, and the probe information acquired by the probe information acquisition unit, Any time And a section number estimating unit for estimating a segment number of vehicles present in said section in.

  A computer program according to an embodiment of the present invention is a computer program for causing a computer to provide traffic information in a section defined by two vehicle detectors provided on a road. Based on the sensing data obtained by the sensor, a traffic volume acquisition unit for acquiring a point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided, and the traffic for a predetermined time Based on the point traffic volume at the upstream point and the downstream point acquired by the volume acquisition unit, the input / output route traffic volume calculation unit for calculating the input / output route traffic volume at the arbitrary time point of the inflow path and the outflow path in the section; A probe information acquisition unit that acquires probe information of a vehicle that has traveled in the section; a point traffic volume acquired by the traffic volume acquisition unit; an entrance / exit traffic volume calculated by the entrance / exit traffic volume calculation unit; On the basis of the acquired probe information in a probe information acquisition unit, to function as a section number estimating unit for estimating a segment number of vehicles present in said zone at said any given time.

  A traffic information providing method according to an embodiment of the present invention is a traffic information providing method for providing traffic information in a section defined by two vehicle detectors provided on a road, obtained by each vehicle sensor. Based on the obtained sensing data, the upstream point where the traffic volume acquisition unit acquires the point traffic volume at an arbitrary point of time between the upstream point and the downstream point where each vehicle sensor is provided, and is acquired over a predetermined time. Based on the point traffic volume at the downstream point, the input / output path traffic volume calculation unit calculates the traffic volume at the arbitrary time of the inflow path and the outflow path in the section, and the probe of the vehicle traveling in the section The probe information acquisition unit acquires information, and based on the acquired point traffic volume, the calculated entrance / exit traffic volume, and the acquired probe information, the number of sections of vehicles existing in the section at the arbitrary time point The number of sections estimation unit estimates .

  According to the present invention, accurate traffic information can be provided even when the acquisition frequency of probe information is low.

It is a schematic diagram which shows an example of the area of the road used as the object for which the traffic information provision apparatus of this Embodiment provides traffic information. It is a block diagram which shows an example of a structure of the traffic information provision apparatus of this Embodiment. It is a schematic diagram which shows an example of the traffic volume of a area. It is a schematic diagram which shows an example of the calculation method of the entrance / exit road traffic volume by the traffic information provision apparatus of this Embodiment. It is a schematic diagram which shows an example of the adjustment method of the total time by the traffic information provision apparatus of this Embodiment. It is a schematic diagram which shows an example of the travel time calculation method by the traffic information provision apparatus of this Embodiment. It is a schematic diagram which shows an example of the congestion position calculation method by the traffic information provision apparatus of this Embodiment. It is a schematic diagram which shows an example of the method of calculating the number of traffic jams when the end of the traffic jam zone is within the zone by the traffic information providing apparatus of the present embodiment. It is a schematic diagram which shows an example of the method of calculating the number of traffic jams when the head of a traffic jam zone is in the zone by the traffic information providing apparatus of this embodiment. It is a schematic diagram which shows an example of the method of calculating the number of traffic jams when the traffic information providing device of the present embodiment has a traffic jam section with its head and tail within the section. It is a schematic diagram which shows the example of the traffic congestion pattern in an area. It is explanatory drawing which shows the example of a transition of a traffic congestion pattern. It is a schematic diagram which shows an example of the estimation method of the traffic jam length when the traffic information provision apparatus of this Embodiment has the tail of the traffic jam section in the zone. It is a schematic diagram which shows an example of the estimation method of the traffic jam length when the traffic information provision apparatus of this Embodiment has the head of the traffic jam zone in the zone. It is a schematic diagram which shows an example of the estimation method of the traffic jam length when the traffic information provision apparatus of this Embodiment has the head and tail of a traffic jam section in a zone. It is a schematic diagram which shows an example of the estimation method of travel time when the probe data by the traffic information provision apparatus of this Embodiment cannot be acquired. It is a flowchart which shows the process sequence of the traffic information provision apparatus of this Embodiment. It is a flowchart which shows the process sequence of the traffic information provision apparatus of this Embodiment.

[Description of Embodiment of Present Invention]
A traffic information providing apparatus according to an embodiment of the present invention is a traffic information providing apparatus that provides traffic information in a section defined by two vehicle sensors provided on a road, and is obtained by each vehicle sensor. A traffic volume acquisition unit for acquiring a point traffic volume at an arbitrary point of the upstream point and the downstream point provided with each vehicle sensor based on the detected data, and the traffic volume acquisition unit for a predetermined time Based on the acquired traffic volume at the upstream and downstream points, the input / output traffic volume calculation unit for calculating the input / output traffic volume of the inflow and outflow routes in the section, and probe information of the vehicle that has traveled in the section Based on the probe information acquisition unit, the point traffic acquired by the traffic acquisition unit, the input / output traffic calculated by the input / output traffic calculation unit, and the probe information acquired by the probe information acquisition unit, Any time And a section number estimating unit for estimating a segment number of vehicles present in said section in.

  A computer program according to an embodiment of the present invention is a computer program for causing a computer to provide traffic information in a section defined by two vehicle detectors provided on a road. Based on the sensing data obtained by the sensor, a traffic volume acquisition unit for acquiring a point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided, and the traffic for a predetermined time Based on the point traffic volume at the upstream point and the downstream point acquired by the volume acquisition unit, the input / output route traffic volume calculation unit for calculating the input / output route traffic volume at the arbitrary time point of the inflow path and the outflow path in the section; A probe information acquisition unit that acquires probe information of a vehicle that has traveled in the section; a point traffic volume acquired by the traffic volume acquisition unit; an entrance / exit traffic volume calculated by the entrance / exit traffic volume calculation unit; On the basis of the acquired probe information in a probe information acquisition unit, to function as a section number estimating unit for estimating a segment number of vehicles present in said zone at said any given time.

  A traffic information providing method according to an embodiment of the present invention is a traffic information providing method for providing traffic information in a section defined by two vehicle detectors provided on a road, obtained by each vehicle sensor. Based on the obtained sensing data, the upstream point where the traffic volume acquisition unit acquires the point traffic volume at an arbitrary point of time between the upstream point and the downstream point where each vehicle sensor is provided, and is acquired over a predetermined time. Based on the point traffic volume at the downstream point, the input / output path traffic volume calculation unit calculates the traffic volume at the arbitrary time of the inflow path and the outflow path in the section, and the probe of the vehicle traveling in the section The probe information acquisition unit acquires information, and based on the acquired point traffic volume, the calculated entrance / exit traffic volume, and the acquired probe information, the number of sections of vehicles existing in the section at the arbitrary time point The number of sections estimation unit estimates .

  Vehicle detectors are installed at an upstream point (start point) and a downstream point (end point) of the road section. Further, an outflow path (off ramp) and an inflow path (on ramp) are provided in the section. The outflow channel and the inflow channel are the entrances and exits of the interchange. That is, when one vehicle detector is installed between the interchanges, the section between the points where the two vehicle detectors are installed across the interchange. The traffic volume acquisition unit acquires the point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided, based on the detection data obtained by each vehicle sensor. That is, the traffic volume acquisition unit, based on the sensing data obtained by the vehicle detector, the point traffic volume Q1 (t) at an arbitrary time point t at the upstream point where the vehicle sensor is provided and the arbitrary point at the downstream point. The point traffic volume Q4 (t) at time t is acquired. Traffic volume is the number of vehicles passed per unit time. The unit time can be set to 5 minutes, for example. In this case, for example, the point traffic Q1 (t) at an arbitrary time t can be the traffic acquired from the time 5 minutes before the time t to the time t.

  The entry / exit traffic calculation unit calculates the entrance / exit traffic of the inflow and outflow routes in the section based on the upstream and downstream spot traffic acquired by the traffic acquisition unit over a predetermined time. It is assumed that the traffic volume Qin (t) at the time t on the inflow route and the traffic volume Qout (t) at the time t on the outflow route. When the traffic flow is relatively stable, that is, when the traffic flow is in a relatively steady state, the increase or decrease in the traffic volume of the section is considered to be negligible, so the section over the predetermined time Tm Traffic flowing into the road (represented as Σ {Q1 (t) + Qin (t)}) and traffic flowing out from the section over the predetermined time Tm (represented as Σ {Q4 (t) + Qout (t)}) Can be equal. That is, the traffic volume (for example, Qin (t) −Qout (t)) at the time point t is the expression {Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)}. Can be calculated. Thereby, the input path traffic volume (for example, the difference between the traffic volume of the inflow path and the traffic volume of the outflow path) at an arbitrary time t can be calculated from the point traffic volumes Q1 (t) and Q4 (t). Even if the traffic volume of the outflow path (off-ramp) and inflow path (on-ramp) cannot be obtained directly or cannot be collected over time, the traffic volume of the inflow path and the traffic volume of the outflow path Can be calculated.

  The probe information acquisition unit acquires probe information of a vehicle that has traveled in the section. The probe information acquisition time point is also simply referred to as an acquisition time point. Probe information is also referred to as probe data, floating car data, or probe car data. For example, information including the position of the vehicle is recorded at a predetermined cycle (for example, 0.1 second, 1 second, etc.). Sent to an external device such as a roadside device. The probe information may include information such as an identification number (vehicle ID) for identifying the vehicle, speed information, time information, and direction information in addition to the vehicle position information.

  The number of sections estimation section is based on the point traffic volume acquired by the traffic volume acquisition section, the input / output path traffic volume calculated by the input / output path traffic volume calculation section, and the probe information acquired by the probe information acquisition section. Estimate the number of sections in the vehicle. Let E (t) be the number of sections at an arbitrary time t. The number of sections E (t) at time t is, for example, the number of sections E (t−Δt) at time (t−Δt) when the number of sections at time (t−Δt) is E (t−Δt). From the sum of the traffic volume Q1 (t) at the upstream point and the traffic volume Qin (t) at the inflow path during the time Δt, the sum of the traffic volume Q4 (t) at the downstream point and the traffic volume Qout (t) at the outflow path It can be obtained by adding the value obtained by subtracting. That is, the number of sections E (t−Δt) at the time point (t−Δt) plus the difference between the number of inflows and outflows into the section during the time Δt is estimated as the number of section E (t) at the time point t. Can do. Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the number of sections) can be provided.

  The traffic information providing apparatus according to the embodiment of the present invention includes a difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired by the traffic volume acquisition unit at the first time point, A difference traffic volume calculation unit for calculating a difference traffic volume between the point traffic volume at the upstream point acquired at a second time point after the time point and the difference between the point traffic volume at the downstream point, and the difference traffic volume calculation unit A predetermined time adjustment unit that adjusts to extend the predetermined time when the absolute value of the calculated differential traffic volume is equal to or greater than a predetermined first threshold value;

  The difference traffic volume calculation unit includes the difference between the point traffic volume acquired by the traffic volume acquisition unit at the first time point, and the upstream point and the downstream data acquired at the second time point after the first time point. The difference traffic volume between each point and the difference in point traffic volume is calculated. Assuming that the first time point is (t-1) and the second time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  The predetermined time adjustment unit adjusts to extend the predetermined time when the absolute value of the differential traffic calculated by the differential traffic calculation unit is equal to or greater than a predetermined first threshold. If the absolute value of the differential traffic EQ (t) is equal to or greater than the first threshold value Th1, the traffic flow is not in a steady state and the traffic flow is considered to vary greatly. By extending, even if the traffic volume between the upstream point and the downstream point fluctuates, it is possible to reduce the error in the traffic volume of the outflow path (off ramp) and the inflow path (on ramp). Alternatively, by using the preset difference number SD between the upstream point and the downstream point, even when the traffic volume between the upstream point and the downstream point fluctuates, the outflow path (off ramp) and the inflow path ( On-ramp traffic volume error can be reduced.

  In the traffic information providing apparatus according to an embodiment of the present invention, the differential traffic volume calculation unit is configured to acquire the upstream point traffic volume and the downstream traffic volume acquired by the traffic volume acquisition unit at a third time point. And the difference between the difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired at the fourth time point after the third time point, and the predetermined time adjustment When the absolute value of the differential traffic volume calculated by the differential traffic volume calculation unit is equal to or smaller than a second threshold value that is smaller than the first threshold value, the unit adjusts to shorten the predetermined time.

  The difference traffic volume calculation unit includes the difference between the point traffic volume acquired by the traffic volume acquisition unit at the third time point and the upstream point and the downstream data acquired at the fourth time point after the third time point. The difference traffic volume between each point and the difference in point traffic volume is calculated. Assuming that the third time point is (t-1) and the fourth time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  The predetermined time adjustment unit considers that the traffic flow has returned to the steady state when the absolute value of the differential traffic volume EQ (t) calculated by the differential traffic volume calculation unit is equal to or less than the second threshold value Th2, which is smaller than the first threshold value Th1. Therefore, it is possible to obtain the traffic volume of the outflow path (off ramp) and the inflow path (on ramp) in the shortest time by shortening the total time (predetermined time) of the traffic volume (for example, returning to the original value). it can. The first threshold Th1 and the second threshold Th2 can be determined in advance according to the section defined by the two vehicle detectors 1.

  The traffic information providing apparatus according to the embodiment of the present invention includes a difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired by the traffic volume acquisition unit at the first time point, A differential traffic volume calculation unit that calculates a differential traffic volume between a point traffic volume at the upstream point acquired at a second time point after the time point and a difference between the spot traffic volume points at the downstream point, and the traffic volume calculation for the entry / exit When the absolute value of the differential traffic volume calculated by the differential traffic volume calculation unit is equal to or greater than a predetermined first threshold, the upstream traffic level and the downstream location acquired by the traffic volume acquisition unit for a predetermined time are provided. A predetermined value is added to or subtracted from the point traffic volume to calculate the traffic volume of the inflow and outflow paths in the section.

  The difference traffic volume calculation unit includes the difference between the point traffic volume acquired by the traffic volume acquisition unit at the first time point, and the upstream point and the downstream data acquired at the second time point after the first time point. The difference traffic volume between each point and the difference in point traffic volume is calculated. Assuming that the first time point is (t-1) and the second time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  When the absolute value of the difference traffic volume calculated by the difference traffic volume calculation unit is equal to or greater than a predetermined first threshold Th1, the entrance / exit traffic volume calculation unit and the upstream point acquired by the traffic volume acquisition unit over a predetermined time and By adding or subtracting a predetermined value to the traffic volume at the downstream point, the traffic volume of the inflow and outflow paths in the section is calculated.

  When the absolute value of the differential traffic volume EQ (t) is equal to or greater than the first threshold Th1, it is considered that the traffic flow is not in a steady state and the traffic flow varies greatly. For example, the traffic volume (Σ {Q1 (t) + Qin (t)}) flowing into the section over a predetermined time Tm and the traffic volume flowing out of the section over the predetermined time Tm (Σ {Q4 (t) + Qout (t)} is not equal, and a difference occurs. Therefore, the predetermined value SD is used as the correction value for the number of vehicles staying in the section, and the difference is canceled out to obtain the traffic volume at the time t. That is, the traffic volume at the time t (for example, Qin (t) −Qout (t)) is {Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)} ± SD It can be calculated by the formula Thereby, the difference between the traffic volume of the inflow path and the traffic volume of the outflow path can be calculated in a predetermined short time without changing (for example, extending) the predetermined time (for example, 5 minutes). The sign and value of the predetermined value SD can be determined in advance according to the section defined by the two vehicle detectors.

  The traffic information providing apparatus according to the embodiment of the present invention calculates a section number of vehicles existing in the section at the time of acquisition of the probe information based on the probe information acquired by the probe information acquisition unit. A number-of-units calculation unit is provided, and the number-of-sections estimation unit estimates the number of sections of vehicles existing in the section at the arbitrary time based on the number of sections calculated by the number-of-sections calculation unit.

  The section number calculation unit calculates the number of sections of vehicles existing in the section at the time of acquisition of the probe information based on the probe information acquired by the probe information acquisition unit. The section number estimation unit estimates the number of sections of vehicles existing in the section at an arbitrary time point based on the number of sections calculated by the section number calculation unit.

  That is, the number of sections (estimated number of sections) at the time when probe information is not obtained (arbitrary time) is based on the number of sections (section number calculated value) calculated at the time when probe information is obtained (time of acquisition). To estimate. For example, the number of sections estimated by the section number estimating unit is expressed as E (t) = E (t−Δt) + u (t) + ξ (t) as the Kalman state equation, and the number of sections calculated by the section number calculating unit is The optimal estimated value EE (t) of the state variable E (t) at time t can be obtained by constructing the Kalman equation as y (t) = E (t) + η (t) as an observation equation. it can. E (t) is the true value (unknown) of the number of sections at time t, y (t) is the calculated number of sections, and u (t) is the difference in the number of inflows and outflows into the section at time t. Ξ (t) is an error in the state equation, and η (t) is an error in the observation equation. Thereby, even if it is a time when probe information cannot be acquired, the number of sections can be estimated accurately.

  The traffic information providing apparatus according to an embodiment of the present invention includes a traffic jam position estimation unit that estimates a position of a traffic jam section in the section at the arbitrary time point based on the number of sections estimated by the section number estimation unit. Prepare.

  The traffic jam position estimation unit estimates the position of the traffic jam section in the section at an arbitrary time point based on the number of sections estimated by the section number estimation unit.

  The position of the traffic jam section includes the head position, the tail position, the traffic jam length, etc. of the traffic jam section. Assuming that there is a traffic jam zone in the zone, the traffic jam number existing in the traffic jam zone at time (t−Δt) is Ec (t−Δt), and the traffic jam number existing in the traffic jam zone at time t is Ec (t). And When the number of sections increases or decreases during the time Δt, the increase or decrease in the number of sections can be considered as an increase or decrease in the number of traffic jams. The increase / decrease dEc (t) of the number of traffic jams at time t is Ec (t) −Ec (t−Δt) = E (t) −E (t−Δt), and the start position of the traffic jam section according to dEc (t) Alternatively, the position of the traffic jam section is estimated by changing the end position. The traffic jam length can be obtained by multiplying the number of traffic jams by the total distance between the head distance and the vehicle length at the time of the traffic jam. Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the position of a traffic jam section) can be provided.

  The traffic information providing apparatus according to the embodiment of the present invention provides a first travel time between the upstream point and the outflow path, between the outflow path and the inflow path, based on the probe information acquired by the probe information acquisition unit. A travel time calculation unit that calculates a second travel time and a third travel time between the inflow path and the downstream point, and the section number calculation unit includes the point traffic volume acquired by the traffic volume acquisition unit, Based on the incoming / outgoing road traffic volume calculated by the incoming / outgoing road traffic volume calculating section and each travel time calculated by the travel time calculating section, the number of sections of vehicles existing in the section at the time of acquisition is calculated.

  Based on the probe information acquired by the probe information acquisition unit, the travel time calculation unit includes a first travel time T1 between the upstream point and the outflow route, a second travel time T2 between the outflow route and the inflow route, and an inflow route. And the third travel time T3 between the downstream points is calculated.

  The number-of-sections calculation section includes the point traffic volumes Q1 (t) and Q4 (t) acquired by the traffic volume acquisition section, and the input / output path traffic volume calculated by the input / output path traffic volume calculation section {Qin (t) -Qout (t)} Based on the travel times T1, T2, T3, and T4 calculated by the travel time calculation unit, the number of sections of vehicles existing in the section at the time of acquisition is calculated.

  The number of sections (the calculated number of sections) is the number of sections calculated when the probe information is obtained. For example, if the travel time of the section is T (= T1 + T2 + T3), the number of sections E (t) at time t is the traffic volume Q1 (t) at the upstream point between time t-T and time t, and time t It is a value obtained by subtracting the traffic volume Qout of the outflow path from time t− (T2 + T3) to time t from the total value with the traffic volume Qin (t) of the inflow path from −T3 to time t. Thereby, the number of sections can be accurately calculated at the time (period) when the probe information can be acquired. Here, the distance between the outflow path (off-ramp) and the inflow path (on-ramp) is often relatively short. In this case, the travel time T2 becomes small enough to be ignored, and T2 + T3 = T3 It can be.

  The traffic information providing apparatus according to the embodiment of the present invention, based on the probe information acquired by the probe information acquisition unit, a traffic jam position calculation unit that calculates the position of the traffic jam section in the zone at the acquisition time point, Based on the position of the traffic congestion section calculated by the traffic congestion position calculation section and the number of sections calculated by the section number calculation section, the number of traffic congestion calculation section for calculating the number of traffic jams of vehicles existing in the traffic congestion section at the time of acquisition; The traffic jam position estimation unit estimates the position of the traffic jam section at the arbitrary time point using the traffic jam number calculated by the traffic jam number calculation unit.

  The congestion position calculation unit calculates the position of the congestion section in the section at the time of acquisition based on the probe information acquired by the probe information acquisition unit. For example, the probe information can be searched from the upstream point to the downstream point of the section, and the speed V can be obtained from the time and position of the vehicle. When the speed V exceeds the predetermined distance LT1 and continuously falls below the threshold speed VT1, the position of the predetermined distance LT1 is calculated as the end position of the traffic jam. Further, a search is further made toward the downstream point of the section, and when the speed V exceeds the predetermined distance LT2 and continuously exceeds the threshold speed VT2, the position of the predetermined distance LT2 is calculated as the head position of the traffic jam. The congestion length can be a distance between the head position and the tail position.

  The traffic pattern indicating the relationship between the section and the traffic jam section is, for example, when the entire section is a traffic jam section (pattern A), when there is no traffic jam section (pattern B), or when only the end of the traffic jam section exists in the section. (Pattern C) can be divided into a case where only the head of the traffic jam section exists in the section (pattern D), and a case where the head and tail of the traffic jam section exist in the section (pattern E).

  The traffic jam number calculation unit calculates the traffic jam number of vehicles existing in the traffic jam section at the time of acquisition based on the position of the traffic jam section calculated by the traffic jam position calculation unit and the number of zones calculated by the segment number calculation unit.

  The traffic jam position estimation unit estimates the position of the traffic jam section at an arbitrary time using the traffic jam number calculated by the traffic jam number calculation unit. Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the position of a traffic jam section) can be provided.

  The traffic information providing apparatus according to the embodiment of the present invention includes a point speed calculation unit that calculates a point speed of the vehicle at the upstream point and the downstream point, based on the sensing data obtained by each vehicle detector, The traffic jam position estimating unit calculates the spot speed calculated by the spot speed calculation unit, a predetermined spot speed threshold, the position of the traffic jam section at the acquisition time calculated by the traffic jam position calculation unit, and the traffic jam number calculation unit. Based on the number of traffic jams and the number of zones calculated by the zone number calculation unit, the position of the traffic jam zone at the arbitrary time point is estimated.

  The point speed calculation unit calculates the point speed V1 (t) of the vehicle at the upstream point and the point speed V4 (t) of the vehicle at the downstream point based on the detection data obtained by each vehicle detector.

  The traffic jam position estimation unit is the spot speed calculated by the spot speed calculation unit, the predetermined spot speed threshold, the position of the traffic jam section at the acquisition time calculated by the traffic jam position calculation unit, the number of traffic jams and the number of zones calculated by the traffic jam number calculation unit Based on the number of sections calculated by the calculation unit, the position of the congestion section at an arbitrary time is estimated.

  For example, when the point speed V1 (t) at the upstream point is smaller than the point speed threshold value VT, it can be considered that the upstream point is in the traffic jam section. On the other hand, when the point speed V1 (t) at the upstream point is larger than the point speed threshold VT, it can be considered that the vehicle is running smoothly and the upstream point is not in the traffic jam section. Similarly, when the point speed V4 (t) at the downstream point is smaller than the point speed threshold VT, it can be considered that the downstream point is in the traffic jam section. On the other hand, when the point speed V4 (t) at the downstream point is larger than the point speed threshold value VT, it can be considered that the vehicle is running smoothly and the downstream point is not in the traffic jam section. Therefore, when the point speed at the upstream point or the downstream point becomes smaller or larger than the point speed threshold value, it is determined to which pattern A to E the patterns A to E of the above-described congestion section have changed. Can do. Moreover, when there is no change in the magnitude relationship between the spot speed and the spot speed threshold, it can be determined that there is no change in the traffic jam pattern. Thereby, even when probe information cannot be acquired, the position of a traffic jam section can be estimated accurately.

  In the traffic information providing apparatus according to the embodiment of the present invention, the number of traffic jam calculation unit is further based on the spot traffic volume acquired by the traffic volume acquisition unit and the spot speed calculated by the spot speed calculation unit. The number of vehicles jammed in the traffic jam section at the time of acquisition is calculated.

  The traffic jam number calculation unit further calculates the traffic jam number of vehicles existing in the traffic jam section at the time of acquisition based on the spot traffic volume acquired by the traffic volume acquisition unit and the spot speed calculated by the spot speed calculation unit.

  When the above-mentioned pattern of the traffic jam section is the pattern A, the traffic jam number Ec (t) is equal to the section number E (t). In the case of pattern B, the number of traffic jams Ec (t) is zero. In the case of pattern C, if the traffic volume at the downstream point is Q4 (t) and the vehicle speed is V4 (t), the number of traffic jams Ec (t) is l (t) × Q4 (t) / V4 (y) Can be calculated. l (t) is the traffic jam length. In the case of pattern D, if the traffic volume at the upstream point is Q1 (t) and the vehicle speed is V1 (t), the number of traffic jams Ec (t) is l (t) × Q1 (t) / V1 (y) Can be calculated. In the case of pattern E, if the distance from the upstream point to the end of the traffic jam is le (t) and the distance from the traffic head to the downstream point is ls (t), the number of traffic jams Ec (t) is E (t) -ls. (T) * Q4 (t) / V4 (t) -le (t) * Q1 (t) / V1 (t). Thereby, the number of traffic jams in the traffic jam section at the time of obtaining probe information can be calculated with high accuracy.

  The traffic information providing apparatus according to the embodiment of the present invention is based on the position of the traffic jam section estimated by the traffic jam position estimation unit and the increase / decrease with the passage of time of the number of zones estimated by the section number estimation unit. A traffic jam length estimation unit for estimating the traffic jam length of the traffic jam section at a later time is provided.

  The traffic jam length estimation unit calculates the traffic jam length of the traffic jam section at the time after acquisition based on the position of the traffic jam section estimated by the traffic jam position estimation unit and the increase / decrease with the passage of time of the number of sections estimated by the number of zone estimation unit. presume.

  The estimated position of the traffic jam section can be obtained, for example, as one of the above-mentioned traffic jam patterns A to E. The increase / decrease in the number of sections between Δt from time t−Δt to time t can be considered as increase / decrease in the number of traffic jams. That is, assuming that the increase / decrease in the number of traffic jams during time Δt is dEc (t) and the increase / decrease in the number of sections is dE (t), dEc (t) = Ec (t) −Ec (t−Δt) = dE (t ) = E (t) −E (t−Δt). Moreover, since it is saturated in a traffic jam section, it can be considered that the density of vehicles (the number of vehicles per distance) does not change. That is, if the congestion length at time t is l (t), Ec (t) / l (t) = Ec (t−Δt) / l (t−Δt). The traffic jam length l (t) at time t can be obtained by l (t−Δt) × Ec (t) / Ec (t−Δt). Thereby, even when probe information cannot be acquired, the traffic jam length can be accurately estimated.

  The traffic information providing apparatus according to the embodiment of the present invention includes a point traffic volume acquired by the traffic volume acquisition unit, an input / output route traffic volume calculated by the input / output route traffic volume calculation unit, and a section estimated by the section number estimation unit. A travel time estimation unit is provided that estimates the travel time at the arbitrary point in the section based on the number of vehicles.

  The travel time estimation unit is based on the point traffic acquired by the traffic acquisition unit, the input / output traffic calculated by the input / output traffic calculation unit, and the number of segments estimated by the number of segments estimation unit at any time of the section. Estimate travel time. When the number of sections E (t) is obtained, the travel time at an arbitrary time point can be estimated based on the time when the number of sections is earned by the point traffic volume at the downstream point of the section. Thereby, even when probe information cannot be acquired, accurate traffic information (for example, travel time) can be provided.

  The traffic information providing apparatus according to the embodiment of the present invention provides a first ratio of the first travel time between the upstream point and the outflow path with respect to the travel time of the section, and between the outflow path and the inflow path with respect to the travel time. A storage unit that stores a second ratio of the second travel time and a third ratio of the third travel time between the inflow path and the downstream point with respect to the travel time, and the travel time estimation unit includes the storage unit The travel time at the arbitrary time point of the section is estimated using the ratios stored in the above.

  The storage unit includes a first ratio of the first travel time between the upstream point and the outflow path with respect to the travel time of the section, a second ratio of the second travel time between the outflow path and the inflow path with respect to the travel time of the section, and the section The third ratio of the third travel time between the inflow path and the downstream point with respect to the travel time is stored.

  T is the travel time of the section, T1 is the first travel time between the upstream point and the outflow route, T2 is the second travel time between the outflow route and the inflow route, and the third is between the inflow route and the downstream point. When the travel time is T3, the first ratio c is c = T1 / T, the second ratio b is b = T2 / T, and the third ratio a is a = T3 / T. Each travel time T, T1, T2, T3 can be calculated at the time when the probe information transmitted by the vehicle that traveled the section is acquired, and each ratio a, b, c is calculated for each travel time T, It can be obtained based on T1, T2, T3, and the obtained ratios a, b, c may be stored in the storage means.

  The travel time estimation unit estimates travel time at an arbitrary point in the section using each ratio stored in the storage unit.

  When the number of sections E (t) is obtained, the travel time can be estimated from the traffic volume earned in the section. For example, if the travel time (departure travel time) until a vehicle that departs from the upstream point at time t arrives at the downstream point is T, from the number of sections E (t) at time t to between time t and time t + T The total of the traffic volume Q4 (t) that can be generated from the downstream point and the traffic volume Qout (t) that can be generated from the outflow route between time t and time t + T1 is subtracted, and the subtracted value from time (t + T1 + T2) to time t + T is subtracted. The value obtained by adding the traffic volume Qin (t) flowing in from the inflow path in between becomes equal to zero. It is assumed that the ratios a, b, and c do not change during the estimated travel time T, and the travel times T1, T2 are expressed by the travel time T using the ratios a, b, c. The travel time T can be estimated by obtaining T for which) is zero. Thereby, even when probe information cannot be acquired, accurate traffic information (for example, travel time) can be provided.

[Details of the embodiment of the present invention]
Hereinafter, a traffic information providing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a section of a road for which the traffic information providing apparatus 100 according to the present embodiment provides traffic information. The road is an expressway, a toll road or the like having a plurality of interchanges (ICs) in the middle. As shown in FIG. 1, a vehicle detector 1 is installed at an upstream point P1 (start point) and a downstream point P4 (end point) of a road section. Further, an outflow path (off ramp) and an inflow path (on ramp) are provided in the section. The outflow channel and the inflow channel are the entrances and exits of the interchange. In the following description, the outflow path is referred to as off-ramp and the inflow path is referred to as on-ramp. There is another interchange on the further upstream side of the upstream point P1 (indicated by a broken line), and the interchange also has an on-ramp and an off-ramp. That is, one vehicle detector is installed between the interchanges. Therefore, the section between the upstream point P1 and the downstream point P4 where the two vehicle detectors are installed with the interchange interposed therebetween is a section.

  In FIG. 1, a point P2 is a point where an off-ramp is provided, and more specifically indicates a position immediately before entering the off-ramp. The point P3 is a point where the on-ramp is provided, and more specifically indicates a position immediately before entering the on-ramp. In addition, the average inter-interchange length of a highway is about 13 km, and in the case of being long, it is about 23 km. In this embodiment, it is possible to provide accurate traffic information of a section sandwiching an interchange. Further, when the vehicle detector is installed near the downstream side of the interchange on-ramp, it is possible to accurately estimate the traffic information between the interchanges.

  FIG. 2 is a block diagram showing an example of the configuration of the traffic information providing apparatus 100 according to the present embodiment. The traffic information providing apparatus 100 according to the present embodiment includes a control unit 10 that controls the entire apparatus, a communication unit 11, a spot traffic volume calculation unit 12, an entrance / exit traffic volume calculation unit 13, a segment number estimation unit 14, and a segment number calculation unit. 15, traffic difference calculation unit 16, time adjustment unit 17, traffic jam position estimation unit 18, travel time calculation unit 19, travel time estimation unit 20, vehicle speed calculation unit 21, traffic jam number calculation unit 22, spot speed calculation unit 23, A traffic jam length estimation unit 24, a storage unit 25, a traffic jam position calculation unit 26, and the like are provided.

  In the present embodiment, in the following description, for the sake of convenience, the operation at the acquisition time point or the acquisition cycle at which the probe data is acquired is referred to as “calculation”, and the probe data cannot be acquired (any time point) or the probe data An operation in a period in which it is not possible to obtain is distinguished by being referred to as “estimation”. The probe data acquisition time includes not only the acquisition time but also a required time zone including the acquisition time (for example, a required period for calculating traffic information).

  The communication unit 11 has a communication function with the vehicle detector 1 and functions as a traffic volume acquisition unit. The communication unit 11 acquires the point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided based on the detection data obtained by each vehicle sensor 1. That is, the communication unit 11 determines the point traffic volume Q1 (t) at an arbitrary point t at the upstream point where the vehicle sensor 1 is provided and the downstream point concerned based on the detection data obtained by the vehicle detector 1. The point traffic Q4 (t) at an arbitrary time t is acquired. Traffic volume is the number of vehicles passed per unit time. The unit time can be set to 5 minutes, for example. In this case, for example, the point traffic Q1 (t) at an arbitrary time t can be the traffic acquired from the time 5 minutes before the time t to the time t.

  The communication unit 11 has a communication function with other roadside devices and the like, and has a function as a probe information acquisition unit. The communication unit 11 acquires probe information of a vehicle that has traveled in the section. The probe information acquisition time point is also simply referred to as an acquisition time point. Probe information is also referred to as probe data, floating car data, or probe car data. For example, information including the position of the vehicle is recorded at a predetermined cycle (for example, 0.1 second, 1 second, etc.). Sent to an external device such as a roadside device. The probe information may include information such as an identification number (vehicle ID) for identifying the vehicle, speed information, time information, and direction information in addition to the vehicle position information. In the present embodiment, the probe information is also referred to as probe data. In addition, the communication unit 11 has a communication function with the vehicle detector 1 and acquires the sensing data obtained by each vehicle detector 1.

  The point traffic volume calculation unit 12 has a function as a traffic volume acquisition unit, and based on the sensing data obtained by the vehicle sensor 1, the traffic volume (point traffic) of the upstream point P1 where the vehicle sensor 1 is installed. Amount) Q1 (t) and the traffic volume (point traffic volume) Q4 (t) at the downstream point P4 are calculated. Traffic volume is the number of vehicles passed per unit time. The unit time can be set to 5 minutes, for example. In this case, for example, the point traffic volume Q1 (t) and Q4 (t) at an arbitrary time point t can be the traffic volume acquired from the time point 5 minutes before the time point t to the time point t. Note that the point traffic volume calculation unit 12 is not an essential configuration, and the traffic volumes Q1 (t) and Q4 (t) calculated by an external device via the communication unit 11 without including the point traffic volume calculation unit 12. ) May be acquired. In this case, the communication unit 11 has a function of a traffic volume acquisition unit.

  The entrance / exit traffic volume calculation part 13 is based on the point traffic volume of the upstream and downstream points acquired by the spot traffic volume calculation part 12 over a predetermined time (also referred to as a total time), and the inflow and outflow paths in the section. Calculate the traffic volume of the entrance / exit. The input / output traffic volume is the traffic volume Qin (t) at the time point t of the on-ramp that is the inflow path and the traffic volume Qout (t) at the time point t of the off-ramp that is the outflow path. The details of the calculation method of the traffic on the entrance and exit will be described later.

  FIG. 3 is a schematic diagram showing an example of the traffic volume in the section. As shown in FIG. 3, at time t, the traffic volume at the upstream point P1 is Q1 (t), the traffic volume at the downstream point P4 is Q4 (t), the traffic volume at the off-ramp is Qout (t), and the traffic volume at the on-ramp. Is Qin (t). At time t, the traffic volume at the point P2 is Q2 (t), and the traffic volume at the point P3 is Q3 (t). In this case, the traffic volume Q2 (t) has a relationship of Q2 (t) = Qout (t) + Q3 (t). The traffic volume Q3 (t) has a relationship of Q3 (t) + Qin (t) = Q4 (t).

  The number of sections estimating unit 14 is based on the point traffic acquired by the point traffic calculation unit 12, the entrance / exit traffic calculated by the entrance / exit traffic calculation unit 13, and the probe information acquired by the communication unit 11. The number of sections of vehicles existing in the section at is estimated.

  Assuming that the number of existing vehicles in the section at time t-Δt is E (t−Δt) and the number of existing vehicles in the section at time t is E (t), the recurrence formula for the number of existing vehicles E (t) is expressed by the following equation (1). Can be expressed as

  Further, the relationship of Q2 (t) = Qout (t) + Q3 (t) and the relationship of Q3 (t) + Qin (t) = Q4 (t) are substituted into the equation (1), and Q2 (t), Q3 ( If t) is deleted, equation (2) can be obtained. The existing number E (t) represented by Expression (2) is a section number estimated value estimated by the section number estimation unit 14.

  As can be seen from equation (2), the number of sections E (t) at time t is equal to the number of sections E (t−Δt) at time (t−Δt), and the traffic volume Q1 ( It can be obtained by adding a value obtained by subtracting the sum of the traffic volume Q4 (t) at the downstream point and the traffic volume Qout (t) of the outflow path from the total of t) and the traffic volume Qin (t) of the inflow path. That is, the number of sections E (t) at time t is obtained by adding the difference in the number of inflows and outflows to the section during time Δt to the number of sections E (t−Δt) at time (t−Δt). Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the number of sections) can be provided.

  Next, a method for calculating the traffic volume of entry / exit will be described. FIG. 4 is a schematic diagram showing an example of a method for calculating traffic on an ingress / egress route by the traffic information providing apparatus 100 according to this embodiment. When the traffic flow is relatively stable, that is, when the traffic flow is in a relatively steady state, the increase or decrease in the traffic volume of the section is considered to be small enough to be ignored. Therefore, the amount of traffic flowing into the section over a predetermined time (total time) Tm (represented as Σ {Q1 (t) + Qin (t)}) and the amount of traffic flowing out of the section over the predetermined time Tm (Σ { Q4 (t) + Qout (t)}).

  That is, the traffic volume (for example, Qin (t) −Qout (t)) at the time point t is the expression {Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)}. Can be calculated. Thereby, the input path traffic volume (for example, the difference between the traffic volume of the inflow path and the traffic volume of the outflow path) at an arbitrary time t can be calculated from the point traffic volumes Q1 (t) and Q4 (t). Even if the traffic volume of the outflow path (off-ramp) and the inflow path (on-ramp) cannot be obtained directly or cannot be collected over time, the traffic volume Qin (t) of the inflow path and the outflow A difference {Qin (t) −Qout (t)} from the road traffic volume Qout (t) can be calculated.

  Note that the difference {Qin (t) −Qout (t)} between the traffic volume Qin (t) of the inflow path and the traffic volume Qout (t) of the outflow path may be a difference at the time of obtaining the probe information. It is also possible to use a difference at a time when it cannot be acquired. Further, the difference {Qin (t) −Qout (t)} at an arbitrary time point t may be calculated from the point traffic Q1 (t) and Q4 (t) at the arbitrary time point t, or You may employ | adopt the value calculated from the point traffic Q1 (t) and Q4 (t) in the past time before arbitrary time t.

  Next, a method for adjusting the predetermined time (total time) Tm will be described.

  The difference traffic volume calculation unit 16 includes a difference between the upstream and downstream points acquired by the point traffic volume calculation unit 12 at the first time point, and an upstream point acquired at the second time point after the first time point. The difference traffic volume with the difference of the traffic volume at each downstream point is calculated. Assuming that the first time point is (t-1) and the second time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  The time adjustment unit 17 has a function as a predetermined time adjustment unit, and when the absolute value of the differential traffic volume EQ (t) calculated by the differential traffic volume calculation unit 16 is equal to or greater than a predetermined first threshold, Adjust to extend.

  FIG. 5 is a schematic diagram showing an example of a total time adjustment method by the traffic information providing apparatus 100 according to the present embodiment. In FIG. 5, the horizontal axis represents time, and the vertical axis represents the differential traffic volume EQ (t). The first threshold value Th1 and the second threshold value Th2 (<Th1) are set equal to positive and negative with respect to 0 as a boundary, and it is determined that the differential traffic volume EQ (t) exceeds the positive direction or the negative direction. As shown in FIG. 5, for example, when the absolute value of the differential traffic volume EQ (t) is equal to or greater than the first threshold Th1, it is considered that the traffic flow is not in a steady state and the traffic flow varies greatly. By extending the total amount of time (predetermined time), even if the traffic volume between the upstream and downstream points fluctuates, errors in traffic on the outflow (off ramp) and inflow (on ramp) can be reduced. can do. For example, if the initial predetermined time is 5 minutes, it can be extended to 10 minutes.

  When the time when the absolute value of the differential traffic volume EQ (t) is equal to or greater than the first threshold value Th1 continues, the initial predetermined time of 5 minutes is increased as time passes, such as 10 minutes, 15 minutes,. You can also

  In addition, the difference traffic volume calculation unit 16 is configured so that the point traffic volume calculation unit 12 acquires the difference between the upstream and downstream points acquired at the third time point, and the upstream acquired at the fourth time point after the third time point. The difference traffic volume between the point and the downstream point is calculated. Assuming that the third time point is (t-1) and the fourth time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  When the absolute value of the differential traffic volume EQ (t) calculated by the differential traffic volume calculation unit 16 is equal to or smaller than the second threshold value Th2, which is smaller than the first threshold value Th1, the time adjustment unit 17 determines that the traffic flow has returned to the steady state. It is possible to calculate the traffic volume of the outflow path (off ramp) and the inflow path (on ramp) in the shortest time by shortening the total time (predetermined time) of traffic volume (for example, returning to the original value). Can do. The first threshold Th1 and the second threshold Th2 can be determined in advance according to the section defined by the two vehicle detectors 1.

  As shown in FIG. 5, when the absolute value of the differential traffic volume EQ (t) becomes equal to or less than the second threshold Th2, it is considered that the traffic flow has returned to the steady state. By shortening (for example, returning to the original value), the traffic volume of the outflow path (off ramp) and the inflow path (on ramp) can be obtained in the shortest time.

  For example, when the initial predetermined time is 5 minutes and the predetermined time is already extended to 10 minutes, when the predetermined time is shortened, 10 minutes can be returned to 5 minutes.

  For example, when the predetermined time is already extended to 20 minutes and the time when the absolute value of the differential traffic volume EQ (t) is equal to or less than the second threshold Th2 continues, It can also be reduced like minutes, 5 minutes ...

  The length of the section (section length) may be a distance that allows the traffic flow until the vehicle that has passed the upstream point to pass the downstream point to be regarded as a steady state. If the average travel time is 25 km / h, the distance that the vehicle can travel from the upstream point to the downstream point of the section in about 5 minutes is about 2 km.

  In addition, when the section length is relatively long, for example, about 10 km, and the traffic flow fluctuates in a non-steady state, the predetermined time Tm is not increased to about 5 minutes, but is increased to, for example, about 25 minutes. It is possible to offset the fluctuations in traffic flow.

  In the above-described example, when the absolute value of the differential traffic volume EQ (t) calculated by the differential traffic volume calculation unit 16 is equal to or greater than the predetermined first threshold value, the configuration is adjusted to extend the predetermined time. It is not limited to this. For example, it is possible to correct using the predetermined value SD without extending the predetermined time. Hereinafter, a case where the predetermined value SD is used will be described.

  The difference traffic volume calculation unit 16 includes the difference between the upstream and downstream points acquired by the point traffic volume calculation unit 12 at the first time point, and the upstream acquired at the second time point after the first time point. The difference traffic volume with the difference of the point traffic volume is calculated for each point and downstream point. Assuming that the first time point is (t-1) and the second time point is t, the differential traffic volume EQ (t) is EQ (t) = {Q1 (t) -Q4 (t)}-{Q1 (t-1 ) -Q4 (t-1)}.

  The entry / exit traffic calculation unit 13 calculates the point traffic over a predetermined time when the absolute value of the differential traffic EQ (t) calculated by the differential traffic calculation unit 16 is equal to or greater than a predetermined first threshold Th1. A predetermined value SD (positive value) is added to or subtracted from the point traffic volume at the upstream and downstream points acquired by the unit 12 to calculate the traffic volume of the inflow and outflow paths in the section.

  When the absolute value of the differential traffic volume EQ (t) is equal to or greater than the first threshold Th1, it is considered that the traffic flow is not in a steady state and the traffic flow varies greatly. For example, the traffic volume (Σ {Q1 (t) + Qin (t)}) flowing into the section over a predetermined time Tm and the traffic volume flowing out of the section over the predetermined time Tm (Σ {Q4 (t) + Qout (t)} is not equal, and a difference occurs. Therefore, the predetermined value SD is used as the correction value for the number of vehicles staying in the section, and the difference is canceled out to obtain the traffic volume at the time t. That is, the traffic volume at the time t (for example, Qin (t) −Qout (t)) is {Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)} ± SD It can be calculated by the formula Thereby, the difference between the traffic volume of the inflow path and the traffic volume of the outflow path can be calculated in a predetermined short time without changing (for example, extending) the predetermined time (for example, 5 minutes). The sign and value of the predetermined value SD can be determined in advance according to the section defined by the two vehicle detectors 1.

  As described above, the absolute value of the differential traffic volume EQ (t) is equal to or greater than the first threshold Th1 and the predetermined time is not changed when the traffic flow fluctuation is considered to be large. For example, Qin (t) −Qout (t)) is obtained from the past performance of the section in the formula {Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)}. By using the predetermined value SD ({Qin (t) −Qout (t)} = {Q4 (t) −Q1 (t)} ± SD), a more accurate outflow path (off-ramp) and The traffic volume of the inflow path (on ramp) can be obtained. The predetermined value SD can be determined in advance according to the section.

  In the present embodiment, it is assumed that the probe data acquisition frequency, that is, the number of unique vehicles transmitting probe data per unit time is small. explain.

  FIG. 6 is a schematic diagram illustrating an example of a travel time calculation method by the traffic information providing apparatus 100 according to the present embodiment. In FIG. 6, only one probe data is shown for simplicity, but probe data from a plurality of vehicles may exist.

  Based on the probe data acquired by the communication unit 11, the travel time calculation unit 19 includes a first travel time T1 between the upstream point P1 and the outflow route, a second travel time T2 between the outflow route and the inflow route, and inflow. A third travel time T3 between the road and the downstream point P4 is calculated. An average value of travel time can also be calculated based on probe data obtained from a plurality of vehicles.

  In addition, the travel time calculation unit 19 uses the first travel time T1, the second travel time T2, the third travel time T3, and the travel time T of the section calculated based on the probe data, and the first ratio of the travel time. c, the second ratio b, and the third ratio a are calculated. The first ratio c is c = T1 / T, the second ratio b is b = T2 / T, and the third ratio a is a = T3 / T. Each ratio can be calculated at the time when the probe data transmitted by the vehicle traveling in the section is acquired, and the obtained ratios a, b, and c are stored in the storage unit 25.

  The number-of-sections calculation unit 15 includes the point traffic volumes Q1 (t) and Q4 (t) acquired by the point traffic volume calculation unit 12, and the entrance / exit traffic volume calculated by the entrance / exit traffic volume calculation unit 13 {Qin (t) −Qout. Based on (t)} and the travel times T1, T2, T3, and T4 calculated by the travel time calculation unit 19, the number of sections of vehicles existing in the section at the time of probe data acquisition is calculated.

  The number of sections E (t) of vehicles existing in the section at the time of probe data acquisition can be obtained by Expression (3).

  As shown in Expression (3), the number of sections E (t) is the number of sections (section number calculated value) calculated when the probe data is obtained. For example, if the travel time of the section is T (= T1 + T2 + T3), the number of sections E (t) at time t is the traffic volume Q1 (t) of the upstream point P1 between time t-T and time t, This is a value obtained by subtracting the off-ramp traffic volume Qout from the time t- (T2 + T3) to the time t from the total value with the on-ramp traffic volume Qin (t) from the time t-T3 to the time t. Thereby, the number of sections can be accurately calculated at the time (period) when the probe data can be acquired. Here, the distance between the outflow path (off-ramp) and the inflow path (on-ramp) is often relatively short. In this case, the travel time T2 becomes small enough to be ignored, and T2 + T3 = T3 It can be.

  Note that the number of sections E (t) of vehicles existing in the section at the time of probe data acquisition can also be obtained by Expression (4).

  Next, a method of estimating an estimated number of sections, which is an estimated value in a time zone when probe data is not obtained, based on the calculated number of sections calculated when probe data is obtained will be described.

  As described above, the section number calculation unit 15 calculates the number of sections of vehicles existing in the section at the time of probe data acquisition based on the probe information acquired by the communication unit 11.

  The section number estimation unit 14 estimates the number of sections of vehicles existing in the section at an arbitrary time point based on the number of sections calculated by the section number calculation unit 15.

  That is, the estimated number of sections at the time when the probe data is not obtained is estimated based on the calculated number of sections at the time when the probe data is obtained. More specifically, the Kalman filter can be assembled with two mathematical expressions representing the estimated value and the calculated value of the number of sections.

  When the Kalman equation is constructed by using the above equation (1) as a state equation and the equation (3) as an observation equation, equations (5) and (6) are obtained.

  In equations (5) and (6), E (t) is the true value (unknown) of the number of sections (variable to be estimated) at time t, and y (t) is calculated based on the probe data at time t. Calculated by using the travel time, u (t) is the difference between the number of inflows and outflows into the section at time t, and ξ (t) is the error (unknown ), And η (t) is an error (unknown) of the observation equation at time t.

  In this case, assuming the characteristics of the errors ξ (t) and η (t) as described later, the optimum estimated value EE (t) of the state variable E (t) at time t and its error (variance) Σ (t) Can be obtained by Equation (7) and Equation (9), respectively. Equation (7) is a filter equation, and Equation (9) is the variance of the optimal estimate. Further, in Expression (7), K (t) is expressed by Expression (8) and is a Kalman gain. It is assumed that the initial value EE (0) of the optimum estimated value is Equation (10) and the initial value Σ (t) of error variance is Equation (11).

  Further, the error characteristics can be assumed as follows. When the normal distribution of mean α and variance B is represented by N (α, B), the initial value E (0) of the estimated value is N (α, B), and ξ (t) is N (0, M ( t)), and η (t) can be represented as N (0, N (t)).

  As described above, the number of sections estimated by the section number estimation unit 14 is expressed as Kalman state equation as E (t) = E (t−Δt) + u (t) + ξ (t). By expressing the calculated number of sections as an observation equation as y (t) = E (t) + η (t) and constructing the Kalman equation, the optimum estimated value EE (t) of the state variable E (t) at time t ). E (t) is the true value (unknown) of the number of sections at time t, y (t) is the calculated number of sections, and u (t) is the difference in the number of inflows and outflows into the section at time t. Ξ (t) is an error in the state equation, and η (t) is an error in the observation equation. Thereby, even if it is a time when probe data cannot be acquired, the number of sections can be estimated accurately.

  Next, a method for estimating the position of a traffic jam section will be described. There are two types of estimation of the position of the traffic jam section: the time when the probe data is obtained, the time zone and the period, and the case where the probe data is not obtained. First, a case where probe data is obtained will be described.

  FIG. 7 is a schematic diagram showing an example of a congestion position calculation method by the traffic information providing apparatus 100 according to the present embodiment. The example of FIG. 7 shows a method for calculating the position of a traffic jam section when probe data exists. For example, it is assumed that n probe data strings P (t) are acquired between time t−ΔT and time t. The probe data sequence P (t) is a sequence of n pieces of probe data p (xi, yi, ti) arranged in time series. Here, xi represents longitude, yi represents latitude, ti represents time, and i is a numerical value from 1 to n.

  The vehicle speed calculation unit 21 calculates the vehicle speed based on the probe data. The speed of the vehicle can be obtained by arranging the probe data of the vehicles that have traveled in the section in time series (probe data string), for example, the distance between two adjacent points and the time difference between the two points. Thereby, a data string Vi (i = 1 to n) of the vehicle speed at a plurality of points in the section is obtained. In FIG. 7B, the vehicle speed is indicated by a solid line.

  The congestion position calculation unit 26 calculates the position of the congestion section in the section at the time of acquisition of the probe data based on the probe data.

  For example, as shown in FIG. 7B, a speed data string Vi (i = 1 to n) is searched from the upstream point P1 to the downstream point P4 of the section, and the speed Vi exceeds a predetermined distance LT1 and is a predetermined number of times. When N1 is continuously below the threshold speed VT1, the position of the predetermined distance LT1 is calculated as the end position of the traffic jam (FIG. 7C). Further, the speed data string is further searched toward the downstream point P4 of the section, and the speed Vi exceeds the predetermined distance LT2 for a predetermined number of times N2 (it is not necessary to be the same number as the number of times N1). When it exceeds VT2, the position of the predetermined distance LT2 is calculated as the head position of the traffic jam (FIG. 7C). The congestion length can be a distance between the head position and the tail position.

  Next, a method for calculating the number of vehicles in a traffic jam section at the time of probe data acquisition will be described.

  FIG. 8 is a schematic diagram illustrating an example of a method for calculating the number of traffic jams when the traffic information provision device 100 according to the present embodiment has a traffic jam tail at the end. In the example of FIG. 8, when the position of the congestion section is calculated by the method illustrated in FIG. 7, the end of the congestion section exists in the section, but the beginning of the congestion section is not in the section, and the downstream point P4 of the section The case where the traffic jam section is connected to the downstream side is shown. Moreover, the traffic volume of the upstream point P1 is set to Q1 (t), and the point speed of the upstream point P1 is set to V1 (t). Moreover, the traffic volume of the downstream point P4 is set to Q4 (t), and the point speed of the downstream point P4 is set to V4 (t).

  The point speed calculation unit 23 calculates the point speed V1 (t) of the vehicle at the upstream point P1 and the point speed V4 (t) of the vehicle at the downstream point P4 based on the sensing data obtained by each vehicle detector 1. To do.

  The number-of-congestions-calculation unit 22 determines the probe based on the position of the congestion section calculated by the congestion position calculation unit 26 (the position of the congestion section calculated by the method illustrated in FIG. 7) and the number of sections calculated by the section number calculation unit 15. Calculate the number of vehicles in the traffic jam section at the time of data acquisition.

  Further, the number of traffic jam calculation unit 22 is based on the spot traffic volume acquired by the spot traffic volume calculation unit 12 and the spot speed calculated by the spot speed calculation unit 23. Calculate the number of traffic jams.

  When the above-mentioned pattern of the traffic jam section is the pattern A, the traffic jam number Ec (t) is equal to the section number E (t). In the case of pattern B, the number of traffic jams Ec (t) is zero. In the case of pattern C, if the traffic volume at the downstream point is Q4 (t) and the vehicle speed is V4 (t), the number of traffic jams Ec (t) is l (t) × Q4 (t) / V4 (y) Can be calculated. l (t) is the traffic jam length. In the case of pattern D, if the traffic volume at the upstream point is Q1 (t) and the vehicle speed is V1 (t), the number of traffic jams Ec (t) is l (t) × Q1 (t) / V1 (y) Can be calculated. In the case of pattern E, if the distance from the upstream point to the end of the traffic jam is le (t) and the distance from the traffic head to the downstream point is ls (t), the number of traffic jams Ec (t) is E (t) -ls. (T) * Q4 (t) / V4 (t) -le (t) * Q1 (t) / V1 (t). Thereby, the number of traffic jams in the traffic jam section at the time of obtaining probe information can be calculated with high accuracy.

  For example, in the example of FIG. 8, the density of the vehicle at the downstream point P4 can be expressed by Q4 (t) / V4 (t), and the density of the vehicle in the traffic jam section (the traffic jam length is l (t)) ( Since the number of vehicles existing per unit distance) can be considered to be the same as the density of vehicles at the downstream point P4, the number of traffic jams Ec (t) at time t can be obtained by equation (12). it can.

  FIG. 9 is a schematic diagram showing an example of a method for calculating the number of traffic jams when the traffic jam providing apparatus 100 according to the present embodiment has a traffic jam head at the beginning. In the example of FIG. 9, when the position of the traffic jam section is calculated by the method illustrated in FIG. 7, the head of the traffic jam section exists in the section but the tail of the traffic jam section is not in the section, and the upstream point P1 of the section The case where a traffic jam section is connected to the upstream side is shown. In the example of FIG. 9, the density of the vehicle at the upstream point P1 can be expressed by Q1 (t) / V1 (t), and the density of the vehicle (unit distance) in the congestion section (the congestion length is l (t)). The number of vehicles present in the win) can be considered to be the same as the density of the vehicles at the upstream point P1, and therefore the number of traffic jams Ec (t) at time t can be obtained by Expression (13).

  FIG. 10 is a schematic diagram illustrating an example of a method for calculating the number of traffic jams when the traffic information providing apparatus 100 according to the present embodiment has a traffic jam zone with its head and tail within the zone. The example of FIG. 10 illustrates a case where the beginning and end of the traffic jam section exist in the zone when the position of the traffic jam zone is calculated by the method illustrated in FIG. In addition, since the positions of the upstream point P1 and the downstream point P4 of the section are known in advance, if the start position and the end position of the traffic jam section are known, the distance le (t) between the upstream point P1 and the traffic jam end position, The distance ls (t) between the downstream point P4 and the head position of the traffic jam can also be obtained.

  In the example of FIG. 10, the density of the vehicle at the upstream point P1 can be expressed by Q1 (t) / V1 (t), and the density of the vehicle in the non-congested section (congestion length is le (t)) (unit: The number of vehicles existing per distance) can be considered to be the same as the density of vehicles at the upstream point P1. Similarly, the density of the vehicle at the downstream point P4 can be expressed by Q4 (t) / V4 (t), and the density of the vehicle in the non-congested section (congestion length is ls (t)) (per unit distance). The number of vehicles present) can be considered to be the same as the density of vehicles at the downstream point P4. Therefore, the number of traffic jams Ec (t) at time t can be obtained by Expression (14).

  Note that when the entire section is a traffic jam section, the number of traffic jams is equal to the number of cars, so the traffic jam quantity Ec (t) at time t can be obtained by Ec (t) = E (t). Further, the vehicle density ρc (t) in the traffic jam section can be obtained by Expression (15).

  FIG. 11 is a schematic diagram illustrating an example of a congestion pattern in a section. As shown in FIG. 11, the traffic congestion pattern indicating the relationship between the section and the traffic jam section is that the entire section is a traffic jam section (pattern A), or there is no traffic jam section (pattern B). It can be divided into a case where there is only a head of a traffic jam section (pattern D), a case where there is only a head of a traffic jam section and a tail (pattern E). Each pattern shown in FIG. 11 can be obtained by the method illustrated in FIG. Thereby, it is possible to calculate the traffic information (the position of the traffic jam section) with high accuracy at the time (cycle) when the probe data can be acquired.

  Next, a method for estimating the position of a traffic jam section at a time point, time zone, and period when probe data cannot be acquired will be described.

  The estimation of the position of the traffic jam section when the probe data cannot be obtained is that the point speeds V1 and V4 at the upstream point P1 and the downstream point P4 of the section have increased from the predetermined point speed threshold VT, or This can be done by determining how the traffic congestion pattern at the time of probe data acquisition has changed depending on whether it has decreased.

  The traffic jam position estimation unit 18 estimates the position of the traffic jam section at an arbitrary time using the traffic jam number calculated by the traffic jam number calculation unit 22. Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the position of a traffic jam section) can be provided.

  More specifically, the traffic jam position estimation unit 18 determines the spot speed calculated by the spot speed calculation unit 23, a predetermined spot speed threshold, and the position of the traffic jam section at the time of probe data acquisition calculated by the traffic jam position calculation unit 26. Based on the number of traffic jams calculated by the traffic jam number calculation unit 22 and the number of zones calculated by the zone number calculation unit 15, the position of the traffic jam zone at an arbitrary time is estimated.

  For example, when the point speed V1 (t) at the upstream point is smaller than the point speed threshold value VT, it can be considered that the upstream point is in the traffic jam section. On the other hand, when the point speed V1 (t) at the upstream point is larger than the point speed threshold VT, it can be considered that the vehicle is running smoothly and the upstream point is not in the traffic jam section. Similarly, when the point speed V4 (t) at the downstream point is smaller than the point speed threshold VT, it can be considered that the downstream point is in the traffic jam section. On the other hand, when the point speed V4 (t) at the downstream point is larger than the point speed threshold value VT, it can be considered that the vehicle is running smoothly and the downstream point is not in the traffic jam section. Therefore, when the point speed at the upstream point or the downstream point becomes smaller or larger than the point speed threshold value, it is determined to which pattern A to E the patterns A to E of the above-described congestion section have changed. Can do. Moreover, when there is no change in the magnitude relationship between the spot speed and the spot speed threshold, it can be determined that there is no change in the traffic jam pattern. Thereby, even when probe information cannot be acquired, the position of a traffic jam section can be estimated accurately. This will be specifically described below.

  FIG. 12 is an explanatory diagram illustrating an example of a transition of a traffic jam pattern. In FIG. 12, the patterns shown in the left column indicate the traffic congestion patterns A to E at the probe data acquisition time Tp. Each traffic congestion pattern at the probe data acquisition time point Tp can be obtained from a time-series position and time data string based on the probe data, and the point velocities V1 and V4 are not used. Moreover, the pattern shown in the upper column shows the congestion patterns A to E at a cycle in which probe data cannot be acquired, that is, at an arbitrary time point (Tp + ΔT). Each traffic congestion pattern at an arbitrary time point (Tp + ΔT) can be obtained according to a combination of the traffic congestion pattern at the probe data acquisition time point Tp, the point speeds V1, V4 at the arbitrary time point (Tp + ΔT), and the point speed threshold value VT. Further, V1 and V4 in each column are point velocities at arbitrary time points (Tp + ΔT) at the upstream point P1 and the downstream point P4, and VT is a predetermined point speed threshold.

  As shown in FIG. 12, the traffic congestion pattern at the probe data acquisition time point Tp is A, the point speed V1 at an arbitrary time point (Tp + ΔT) is V1 <VT, and the point speed V4 at an arbitrary time point (Tp + ΔT) is When V4 <VT, the congestion pattern at an arbitrary time point (Tp + ΔT) remains A.

  The traffic congestion pattern at the probe data acquisition time point Tp is A, the point speed V1 at an arbitrary time point (Tp + ΔT) is V1> VT, and the point speed V4 at an arbitrary time point (Tp + ΔT) is V4 <VT. In this case, the traffic congestion pattern at an arbitrary time point (Tp + ΔT) is C.

  The traffic congestion pattern at the probe data acquisition time point Tp is A, the point speed V1 at an arbitrary time point (Tp + ΔT) is V1 <VT, and the point speed V4 at an arbitrary time point (Tp + ΔT) is V4> VT. In this case, the traffic congestion pattern at an arbitrary time point (Tp + ΔT) is D.

  Further, the congestion pattern at the probe data acquisition time point Tp is A, the point speed V1 at an arbitrary time point (Tp + ΔT) is V1> VT, and the point speed V4 at an arbitrary time point (Tp + ΔT) is V4> VT. In this case, the traffic congestion pattern at an arbitrary time point (Tp + ΔT) is E.

  As shown in FIG. 12, when the congestion pattern at the probe data acquisition time point Tp is from B to E, the congestion pattern at an arbitrary time point (Tp + ΔT) can be obtained as in the case of the pattern A.

  Furthermore, although not illustrated in FIG. 12, each traffic congestion pattern at an arbitrary time point (Tp + 2ΔT) includes a traffic congestion pattern at a time point (Tp + ΔT) one cycle before, a point speed V1, V4 at an arbitrary time point (Tp + 2ΔT), and It can be determined according to the combination of the point speed thresholds VT.

  For example, the traffic congestion pattern at the time point (Tp + ΔT) one cycle before is A, the point speed V1 at an arbitrary time point (Tp + 2ΔT) is V1 <VT, and the point speed V4 at an arbitrary time point (Tp + 2ΔT) is V4 < In the case of VT, the traffic congestion pattern at an arbitrary time point (Tp + 2ΔT) remains A.

  Further, the traffic congestion pattern at the time point (Tp + ΔT) one cycle before is A, the point speed V1 at an arbitrary time point (Tp + 2ΔT) is V1> VT, and the point speed V4 at an arbitrary time point (Tp + 2ΔT) is V4 < In the case of VT, the congestion pattern at an arbitrary time point (Tp + 2ΔT) is C.

  Further, the traffic congestion pattern at the time point (Tp + ΔT) one cycle before is A, the point speed V1 at an arbitrary time point (Tp + 2ΔT) is V1 <VT, and the point speed V4 at an arbitrary time point (Tp + 2ΔT) is V4>. In the case of VT, the congestion pattern at an arbitrary time point (Tp + 2ΔT) is D.

  Further, the traffic congestion pattern at the time point (Tp + ΔT) one cycle before is A, the point speed V1 at an arbitrary time point (Tp + 2ΔT) is V1> VT, and the point speed V4 at an arbitrary time point (Tp + 2ΔT) is V4> In the case of VT, the congestion pattern at an arbitrary time point (Tp + 2ΔT) is E.

  Similarly to the case of the pattern A, the congestion pattern at an arbitrary time point (Tp + 2ΔT) can be obtained also when the traffic congestion pattern at the time point (Tp + ΔT) one cycle before is B to E. Thus, when the traffic congestion pattern at the probe data acquisition time Tp is obtained, it is possible to obtain the traffic congestion pattern at any time (Tp + ΔT), (Tp + 2ΔT), (Tp + 3ΔT), (Tp + 4ΔT). It becomes. Thereby, even when probe data cannot be acquired, the position of a traffic jam section can be estimated with high accuracy.

  Based on the number of sections estimated by the section number estimation unit 14, the congestion position estimation unit 18 estimates the position of the congestion section in the section at an arbitrary time.

  The position of the traffic jam section includes the head position, the tail position, the traffic jam length, etc. of the traffic jam section. Assuming that there is a traffic jam zone in the zone, the traffic jam number existing in the traffic jam zone at time (t−Δt) is Ec (t−Δt), and the traffic jam number existing in the traffic jam zone at time t is Ec (t). And When the number of sections increases or decreases during the time Δt, the increase or decrease in the number of sections can be considered as an increase or decrease in the number of traffic jams. The increase / decrease dEc (t) of the number of traffic jams at time t is Ec (t) −Ec (t−Δt) = E (t) −E (t−Δt), and the start position of the traffic jam section according to dEc (t) Alternatively, the position of the traffic jam section is estimated by changing the end position. The traffic jam length can be obtained by multiplying the number of traffic jams by the total distance between the head distance and the vehicle length at the time of the traffic jam. Thereby, even when the acquisition frequency of probe information is low, accurate traffic information (for example, the position of a traffic jam section) can be provided.

  Hereinafter, the estimation of the traffic jam length of the traffic jam section for each traffic jam pattern will be described.

  The traffic jam length estimation unit 24 determines the traffic jam section at the time after the acquisition time based on the position of the traffic jam section estimated by the traffic jam position estimation unit 18 and the increase / decrease of the number of sections estimated by the segment number estimation unit 14 over time. Estimate the congestion length. The estimated position of the traffic jam section can be obtained as one of the traffic jam patterns A to E exemplified in FIG.

  FIG. 13 is a schematic diagram illustrating an example of a method for estimating a traffic jam length when the traffic information provision device 100 according to the present embodiment has an end of a traffic jam zone within the zone, and FIG. 14 is a traffic information provision according to the present embodiment. It is a schematic diagram which shows an example of the estimation method of the congestion length when the head of the congestion area by the apparatus 100 exists in the area. In the case of FIGS. 13 and 14, the increase / decrease in the number of sections between Δt from time t−Δt to time t can be considered as the increase / decrease in the number of traffic jams. That is, assuming that the increase / decrease in the number of traffic jams during time Δt is dEc (t) and the increase / decrease in the number of sections is dE (t), dEc (t) = Ec (t) −Ec (t−Δt) = dE (t ) = E (t) −E (t−Δt). Further, since the vehicle is saturated in the traffic jam section, it can be considered that the density of vehicles in the traffic jam section does not change before and after the lapse of Δt time. In this case, Expression (16) is established.

  When the left side of Expression (5) is expressed by dEc (t), Expression (17) is obtained. The traffic jam length l (t) in the traffic jam section can be obtained by equation (18).

  FIG. 15 is a schematic diagram illustrating an example of a method for estimating a traffic jam length when the traffic information providing apparatus 100 according to the present embodiment has a traffic jam section having a head and a tail at the end. In this case, the number of traffic jams Ec (t) at time t can be estimated by equation (19), similarly to equation (14).

  Assuming that the density of vehicles in a traffic jam section does not change even when the traffic jam length l (t) changes, equation (20) is established, and the traffic jam length l (t) can be obtained by equation (21). .

  Further, when the density of the vehicle in the non-congested section between the upstream point P1 and the end position of the congested section is ρ1 (t), the density ρ1 (t) can be obtained by Expression (22). Further, when the density of the vehicle in the non-congested section between the downstream point P4 and the head position of the congested section is ρ4 (t), the density ρ4 (t) can be obtained by Expression (23).

  In this case, the distances le (t) and ls (t) of the non-congested section can be obtained by Expression (24) or Expression (25).

  As described above, even when the probe data cannot be acquired, it is possible to accurately estimate the traffic jam length.

  Next, a method for estimating the travel time of a section at a timing when probe data cannot be acquired will be described.

  The travel time estimator 20 calculates the section traffic based on the point traffic obtained by the spot traffic calculator 12, the entrance / exit traffic calculated by the entrance / exit traffic calculator 13, and the number of sections estimated by the section number estimator 14. Estimate travel time at any time. When the number of sections E (t) is obtained, the travel time at an arbitrary time point can be estimated based on the time when the number of sections is earned by the point traffic volume at the downstream point of the section. Thereby, even when probe information cannot be acquired, accurate traffic information (for example, travel time) when a traffic jam occurs can be provided.

  More specifically, the storage unit 25 stores the first ratio a of the first travel time T1 between the upstream point and the outflow path with respect to the travel time T of the section, and between the outflow path and the inflow path with respect to the travel time T of the section. The second ratio b of the second travel time T2 and the third ratio c of the third travel time T3 between the inflow path and the downstream point with respect to the travel time T of the section are stored.

  That is, the travel time of the section is T, the first travel time between the upstream point and the outflow route is T1, the second travel time between the outflow route and the inflow route is T2, and the distance between the inflow route and the downstream point is When the third travel time is T3, the first ratio c is c = T1 / T, the second ratio b is b = T2 / T, and the third ratio a is a = T3 / T. . Each travel time T, T1, T2, T3 can be calculated at the time when the probe information transmitted by the vehicle that traveled the section is acquired, and each ratio a, b, c is calculated for each travel time T, It can be determined based on T1, T2, and T3.

  The travel time estimation unit 20 estimates the travel time at an arbitrary point in the section using each ratio stored in the storage unit 25.

  FIG. 16 is a schematic diagram illustrating an example of a travel time estimation method when probe data cannot be acquired by the traffic information providing apparatus 100 according to the present embodiment. If the number of existing vehicles E (t) at the time t is obtained, the point traffic volume is Q1 (t), Q4 (t), the traffic volume is Qin (t), Qout (t), the time zone t The departure travel time T of the vehicle that departs from the upstream point P1 can be obtained by Expression (26).

  That is, when the number of sections E (t) is obtained, the travel time can be estimated from the traffic volume earned in the section regardless of whether there is a congested section in the section. For example, if the travel time (departure travel time) until a vehicle that departs from the upstream point at time t arrives at the downstream point is T, from the number of sections E (t) at time t to between time t and time t + T The total of the traffic volume Q4 (t) that can be generated from the downstream point and the traffic volume Qout (t) that can be generated from the outflow route between time t and time t + T1 is subtracted, and the subtracted value from time (t + T1 + T2) to time t + T is subtracted. The value obtained by adding the traffic volume Qin (t) flowing in from the inflow path in between becomes equal to zero. In Expression (26), cT is T1, and (b + c) T is T1 + T2.

  If the ratios a, b, and c are constant during the estimated travel time T, and the integration range of the traffic volumes Qin (t) and Qout (t) is matched from t to t + T, the expressions (28) and ( 29) and formula (30) are obtained. That is, it is assumed that the ratios a, b, and c do not change during the estimated travel time T, and the travel time T1, T2 is expressed by the travel time T using the ratios a, b, c. ), The travel time T can be estimated.

  Thereby, even when probe information cannot be acquired, accurate traffic information (for example, travel time) can be provided. In Equation (30), when the ratios a and c can be considered to be the same, that is, when the travel times T1 and T3 can be considered to be the same, Equation (30) is input. It can be calculated using the road traffic volume {Qin (t) −Qout (t)}. Alternatively, the arrival travel time T may be calculated using the upstream traffic volume Q1 (t) instead of using the downstream traffic volume Q4 (t).

  Next, operation | movement of the traffic information provision apparatus 100 of this Embodiment is demonstrated. 17 and 18 are flowcharts showing the processing procedure of the traffic information providing apparatus 100 according to the present embodiment. For convenience, it is assumed that the main subject of the processing is the control unit 10. The control unit 10 acquires sensing data from vehicle detectors installed at the upstream and downstream points of the section (S11), and calculates the traffic volume at the upstream and downstream points of the section (S12).

  The control unit 10 calculates the traffic volume of on-ramp and off-ramp (S13), and determines whether probe data has been acquired, that is, whether probe data can be acquired (S14). When the probe data can be acquired (YES in S14), the control unit 10 estimates the number of sections (S15).

  Based on the probe data, the control unit 10 performs a first travel time between the upstream point and the off-ramp, a second travel time between the off-ramp and the on-ramp, and a third travel time between the on-ramp and the downstream point. And the travel time of the section is calculated (S16).

  The control unit 10 calculates the number of sections using the calculated travel times (S17), and calculates the optimum estimated value of the number of sections using the estimated value of the number of sections and the calculated value of the number of sections (S18). The control unit 10 calculates the vehicle speed (sequence of speed data) based on the probe data (S19), and calculates the position of the traffic jam section based on the vehicle speed and the threshold speed (S20).

  The control 10 determines whether or not to end the process (S21). If the process is not ended (NO in S21), the process after step S11 is continued and the process is ended (YES in S21). finish.

  When probe data cannot be acquired in step S14 (NO in S14), the control unit 10 estimates the number of sections (S22), and calculates point velocities at the upstream and downstream points based on the sensed data ( S23).

  The control unit 10 estimates the position of the traffic jam section based on the position of the traffic jam section at the time of probe data acquisition, the point speed and the point speed threshold (S24), and estimates the traffic jam length of the traffic jam section (S25).

  The control unit 10 is based on the ratios c, b, a of the travel times T1, T2, T3 between the points with respect to the section travel time T at the time of probe data acquisition, the traffic volume of the on-ramp and off-ramp and the traffic volume of the downstream point. The travel time of the section is estimated (S26), and the process of step S21 is performed.

  The traffic information providing apparatus 100 according to the present embodiment can be realized using a general-purpose computer including a CPU, a RAM, and the like. That is, as shown in FIGS. 17 and 18, a computer program that defines each processing procedure is recorded on a computer program recording medium such as a CD, a DVD, or a USB memory, and the computer program is stored in a RAM provided in the computer. By loading and executing the computer program by the CPU, the traffic information providing apparatus 100 can be realized on the computer.

  The disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 10 Control part 11 Communication part 12 Point traffic volume calculation part 13 Entrance / exit traffic volume calculation part 14 Section number estimation part 15 Section number calculation part 16 Differential traffic volume calculation part 17 Time adjustment part 18 Congestion position estimation part 19 Travel time calculation part 20 Travel time estimation unit 21 Vehicle speed calculation unit 22 Number of traffic jam calculation unit 23 Point speed calculation unit 24 Traffic jam length estimation unit 25 Storage unit 26 Traffic jam position calculation unit

Claims (15)

A traffic information providing device that provides traffic information in a section defined by two vehicle detectors provided on a road,
Based on the sensing data obtained by each vehicle sensor, a traffic volume acquisition unit that acquires the point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided,
Based on the traffic volume at the upstream and downstream points acquired by the traffic volume acquisition unit over a predetermined time, the traffic volume calculation unit for entering and leaving the inflow and outflow paths in the section When,
A probe information acquisition unit for acquiring probe information of a vehicle that has traveled in the section;
Based on the point traffic acquired by the traffic acquisition unit, the entrance / exit traffic calculated by the entrance / exit traffic calculation unit, and the probe information acquired by the probe information acquisition unit, within the section at the arbitrary time point A traffic information providing device comprising: a section number estimation unit that estimates the number of sections of vehicles existing in the vehicle. The difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired by the traffic volume acquisition unit at the first time point, and the upstream point acquired at the second time point after the first time point. A differential traffic volume calculation unit for calculating a differential traffic volume between the point traffic volume of and the difference between the point traffic volume at the downstream point,
2. The traffic according to claim 1, further comprising: a predetermined time adjustment unit that adjusts to extend the predetermined time when the absolute value of the differential traffic calculated by the differential traffic calculation unit is equal to or greater than a predetermined first threshold value. Information providing device. The differential traffic volume calculation unit
The difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired by the traffic acquisition unit at the third time point, and the upstream point acquired at the fourth time point after the third time point And calculate the difference traffic volume between the point traffic volume and the difference between the downstream point traffic volume,
The predetermined time adjustment unit includes:
The traffic information providing apparatus according to claim 2, wherein when the absolute value of the differential traffic volume calculated by the differential traffic volume calculation unit is equal to or smaller than a second threshold value that is smaller than the first threshold value, the traffic information providing device adjusts to shorten the predetermined time. . The difference between the point traffic volume at the upstream point and the point traffic volume at the downstream point acquired by the traffic volume acquisition unit at the first time point, and the upstream point acquired at the second time point after the first time point. A difference traffic volume calculation unit for calculating a difference traffic volume between the point traffic volume of and the difference between the point traffic volume at the downstream point,
The entrance / exit traffic calculation unit
When the absolute value of the differential traffic volume calculated by the differential traffic volume calculation unit is equal to or greater than a predetermined first threshold, the point traffic volume at the upstream and downstream points acquired by the traffic volume acquisition unit over a predetermined time The traffic information providing apparatus according to claim 1, wherein a predetermined value is added to or subtracted from to calculate the traffic volume of the inflow and outflow paths in the section. Based on the probe information acquired by the probe information acquisition unit, comprising a section number calculation unit that calculates the number of sections of vehicles existing in the section at the time of acquisition of the probe information,
The section number estimation unit is
The traffic information according to any one of claims 1 to 4, wherein the number of sections of vehicles existing in the section at the arbitrary time point is estimated based on the number of sections calculated by the section number calculation unit. Providing device.   The traffic information providing apparatus according to claim 5, further comprising: a traffic jam position estimation unit that estimates a position of a traffic jam section in the zone at the arbitrary time point based on the number of zones estimated by the zone number estimation unit. Based on the probe information acquired by the probe information acquisition unit, a first travel time between the upstream point and the outflow route, a second travel time between the outflow route and the inflow route, and the inflow route and the downstream point A travel time calculation unit for calculating the third travel time between
The section number calculation unit
Based on the point traffic acquired by the traffic acquisition unit, the entrance / exit traffic calculated by the entrance / exit traffic calculation unit, and the travel times calculated by the travel time calculation unit, The traffic information providing device according to claim 5, wherein the number of sections of vehicles existing in the vehicle is calculated. Based on the probe information acquired by the probe information acquisition unit, a traffic jam position calculation unit that calculates the position of the traffic jam section in the zone at the acquisition time point,
Based on the position of the traffic congestion section calculated by the traffic congestion position calculation section and the number of sections calculated by the section number calculation section, the number of traffic congestion calculation section for calculating the number of traffic jams of vehicles existing in the traffic congestion section at the time of acquisition; With
The traffic jam position estimation unit
The traffic information providing apparatus according to claim 6, wherein the position of a traffic jam section at the arbitrary time point is estimated using the traffic jam number calculated by the traffic jam number calculation unit. Based on the sensing data obtained by each vehicle sensor, a point speed calculation unit that calculates the point speed of the vehicle at the upstream point and the downstream point,
The traffic jam position estimation unit
The point speed calculated by the point speed calculation unit, the predetermined point speed threshold, the position of the traffic jam section at the acquisition time calculated by the traffic jam position calculation unit, the number of traffic jams calculated by the traffic jam number calculation unit, and the number of zones calculated The traffic information providing apparatus according to claim 8, wherein the position of the traffic jam section at the arbitrary time point is estimated based on the number of sections calculated by the section. The traffic number calculation unit
Furthermore, the number of traffic jams of vehicles existing in the traffic jam section at the time of acquisition is calculated based on the spot traffic volume acquired by the traffic volume acquisition unit and the spot speed calculated by the spot speed calculation unit. The traffic information providing device described.   Based on the position of the congestion section estimated by the congestion position estimation unit and the increase / decrease of the number of sections estimated by the number of sections estimation unit over time, the congestion length of the congestion section at the time after the acquisition time is estimated. The traffic information providing apparatus according to claim 6, further comprising a traffic jam length estimation unit.   Travel at any point in time in the section based on the point traffic volume acquired by the traffic volume acquisition section, the traffic volume calculated by the input / output path traffic volume calculation section, and the number of sections estimated by the section number estimation section The traffic information providing apparatus according to claim 1, further comprising a travel time estimation unit that estimates time. A first ratio of the first travel time between the upstream point and the outflow path to the travel time of the section, a second ratio of the second travel time between the outflow path and the inflow path to the travel time, and the travel time A storage unit for storing a third ratio of the third travel time between the inflow path and the downstream point with respect to
The travel time estimation unit
The traffic information providing apparatus according to claim 12, wherein a travel time at the arbitrary time point of the section is estimated using each ratio stored in the storage unit. A computer program for causing a computer to provide traffic information in a section defined by two vehicle detectors provided on a road,
Computer
Based on the sensing data obtained by each vehicle sensor, a traffic volume acquisition unit that acquires the point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided,
Based on the point traffic volume at the upstream and downstream points acquired by the traffic volume acquisition unit over a predetermined time, the traffic volume at the arbitrary time of the inflow and outflow paths in the section is calculated. I / O traffic volume calculation unit,
A probe information acquisition unit for acquiring probe information of a vehicle that has traveled in the section;
Based on the point traffic acquired by the traffic acquisition unit, the entrance / exit traffic calculated by the entrance / exit traffic calculation unit, and the probe information acquired by the probe information acquisition unit, within the section at the arbitrary time point A computer program that functions as a section number estimation unit that estimates the number of sections in a vehicle. A traffic information providing method for providing traffic information in a section defined by two vehicle detectors provided on a road,
Based on the sensing data obtained by each vehicle detector, the traffic volume acquisition unit acquires the point traffic volume at an arbitrary point of the upstream point and the downstream point where each vehicle sensor is provided,
Based on the traffic volume at the upstream and downstream points acquired over a predetermined time, the traffic volume calculation unit for the traffic at the arbitrary time of the inflow and outflow paths in the section is Calculate
The probe information acquisition unit acquires probe information of a vehicle that has traveled in the section,
Traffic information in which the number-of-sections estimation unit estimates the number of sections of vehicles existing in the section at the arbitrary time point based on the acquired point traffic volume, the calculated input / output traffic volume, and the acquired probe information. How to provide.

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