JP2019191802A - Congestion degree determination device, congestion degree determination method, and computer program - Google Patents

Abstract

To accurately determine a congestion degree by using a link average speed based on probe information.SOLUTION: The present invention relates to a device for determining a congestion degree of a link corresponding to a road. The device comprises: a communication unit for receiving probe information from a probe vehicle; and an information processing unit which calculates a link average speed of the probe vehicle by using the received probe information and compares the calculated link average speed with a speed threshold, thereby determining a congestion degree of a link corresponding to a road that the probe vehicle passed. The speed threshold used by the information processing unit consists of a speed threshold Ths calculated by a following calculation formula of Ths=3.6×L/{TS+3.6×L/VS}, wherein L(m) is a link length, TS (second) are stop factor terms (seconds) generated until the probe vehicle passes the link, and VS(km/h) is a speed that is estimated when a vehicle passes on the road.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a congestion degree determination device, a congestion degree determination method, and a computer program.

Patent Document 1 describes a traffic jam information generating device that generates traffic jam information based on probe information received from a probe vehicle.
This device calculates the link average speed of the probe vehicle for each road link based on the received probe information, and compares the calculated link average speed with a predetermined threshold to determine the degree of link congestion. is there.

JP 2012-137833 A

In the case of the link average speed using the probe information as the original data, for example, due to the influence of the signal waiting time at the intersection, the link average speed tends to decrease as the link becomes shorter.
For this reason, in the conventional apparatus that compares the link average speed calculated from the probe information with a fixed threshold value, in the determination of the degree of traffic congestion of a link having a relatively short link length, only one signal waiting is actually generated at the intersection. Even in a smooth traffic situation, there is a possibility of erroneous determination that the traffic is congested or congested.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a congestion degree determination device and the like that can accurately determine a congestion degree using a link average speed based on probe information.

  (1) An apparatus according to an aspect of the present invention is a congestion degree determination apparatus that determines a congestion degree of a link corresponding to a road, a communication unit that receives probe information from a probe vehicle, and a reception The link average speed of the probe vehicle is calculated using the probe information and the calculated link average speed is compared with a speed threshold value to determine the degree of congestion of the link corresponding to the road on which the probe vehicle passes. The speed threshold value used by the information processing unit includes a speed threshold value Ths calculated by the following calculation formula.

Ths = 3.6 × L / {TS + 3.6 × L / VS}
L (m): Link length TS (seconds): Stop factor term (seconds) that occurs before the probe vehicle passes the link
VS (km / h): the speed assumed when the vehicle travels on the road

  (8) A method according to an aspect of the present invention is a method for determining a degree of congestion of a link corresponding to a road, using a first step of receiving probe information from a probe vehicle and the received probe information. Calculating a link average speed of the probe vehicle, and comparing the calculated link average speed with a speed threshold to determine a congestion degree of a link corresponding to a road on which the probe vehicle passes, The speed threshold used in the second step is composed of the speed threshold Ths calculated by the above calculation formula.

  (9) A program according to an aspect of the present invention is a computer program for causing a computer to function as a device for determining the degree of congestion of a link corresponding to a road, and the computer receives probe information from a probe vehicle. The link average speed of the probe vehicle is calculated using the received first probe information and the probe information received, and the calculated link average speed is compared with a speed threshold value so as to correspond to the road on which the probe vehicle passes. A second step of determining the degree of congestion of the link, and the speed threshold used in the second step is a speed threshold Ths calculated by the above calculation formula.

  According to the present invention, it is possible to accurately determine the degree of congestion using an average link speed based on probe information.

1 is an overall configuration diagram of an information providing system according to an embodiment of the present invention. It is a block diagram of the information provision apparatus which comprises an information provision system, and a vehicle-mounted apparatus. It is a graph which shows the relationship between the queue in an intersection, and the traveling locus of a vehicle. It is a graph which shows the relationship between link length and link average speed. It is a flowchart which shows an example of the congestion degree determination process which the information processing part of an information provision apparatus performs.

<Outline of Embodiment of the Present Invention>
Hereinafter, an outline of embodiments of the present invention will be listed and described.
(1) The device of the present embodiment is a device that determines the degree of congestion of a link corresponding to a road, and includes a communication unit that receives probe information from the probe vehicle and the probe vehicle using the received probe information. An information processing unit for calculating a link average speed and comparing the calculated link average speed with a speed threshold to determine a degree of congestion of a link corresponding to a road on which the probe vehicle has traveled. The speed threshold used by the unit is composed of a speed threshold Ths calculated by the following calculation formula.

Ths = 3.6 × L / {TS + 3.6 × L / VS}
L (m): Link length TS (seconds): Stop factor term (seconds) that occurs before the probe vehicle passes the link
VS (km / h): the speed assumed when the vehicle travels on the road

  According to the congestion degree determination device of the present embodiment, since the speed threshold Ths that varies according to the link length L is adopted, the link average speed based on the probe information is compared with the conventional device in which the threshold is a fixed value. The used congestion level can be determined more accurately.

(2) In the congestion degree determination device of the present embodiment, when the link corresponds to a general road, the speed threshold Ths (k) calculated by the following calculation formula may be adopted as the speed threshold Ths. .
Th (k) = 3.6 × L / {(k × CG) + 3.6 × L / Vo}
k (times): The number of cycles that a vehicle stopped in front of the end intersection with a red light will wait until it passes through the intersection C (seconds): cycle length of the end intersection G (seconds): blue time zone at the end intersection Time length Vo (km / h): speed assumed when a vehicle travels on a general road

  According to the congestion degree determination device of the present embodiment, when the link corresponds to a general road, the above speed threshold Th (k) is adopted. Therefore, by arbitrarily setting the value of the cycle count k, various degrees can be obtained. You can determine the degree of traffic jam.

(3) For example, the speed threshold Th (k) includes at least one of the first threshold Th (1) when k = 1 and the second threshold Th (2) when k = 2. It is preferable.
In this case, it is possible to determine whether the link is smooth or congested by comparing the link average speed with the first threshold Th (1), and by comparing the link average speed with the second threshold Th (2), the link is not It is possible to determine whether it is a traffic jam or a traffic jam.

  (4) In the congestion degree determination device of the present embodiment, a predetermined maximum value is set for the first and second threshold values Th (1) and Th (2), and the information processing unit When the calculated values of the first and second threshold values Th (1) and Th (2) exceed the maximum value, the maximum value is preferably set as the speed threshold value.

The reason for this is that when the link length L is sufficiently larger than 3.6 × L / Vo than (CG), the value of the speed threshold Th (1) becomes excessive, and although it is well, there is an error as congestion. This is because the possibility of determination increases.
In addition, when the link length L is sufficiently larger than 3.6 × L / Vo than (2 × CG), the value of the speed threshold Th (2) becomes excessive, and traffic jams occur even though there is no traffic jam. This is because the possibility of erroneous determination increases.

(5) In the congestion degree determination apparatus of the present embodiment, it is preferable that the assumed speed Vo is set to a different value according to at least one of the road width of the general road and the presence or absence of speed regulation.
In this way, the speed threshold Th (k) can be set to an accurate value according to the road width of the general road and the presence or absence of speed regulation, so that the degree of congestion of the link can be determined more accurately.

(6) In the congestion degree determination apparatus according to the present embodiment, when the link corresponds to a section of an expressway connected to a service area or a parking area, the speed threshold Ths is a speed threshold calculated by the following calculation formula: It consists of Thr.
Thr = 3.6 × L / {Tr + 3.6 × L / Vr}
Tr (seconds): Stopping time generally assumed when a vehicle driver takes a break in the area Vr (km / h): Generally assumed when a vehicle passes through a section of a highway connected to the area Speed

According to the congestion degree determination device of the present embodiment, the congestion degree of the link is determined by the speed threshold Thr described above using the stop time Tr that is generally assumed when resting in a service area or a parking area as a stop factor term TS. Determined.
For this reason, the congestion degree of the link corresponding to the section of the highway connected to a service area or a parking area can be determined more accurately.

(7) In the congestion degree determination apparatus according to the present embodiment, when the link corresponds to a section of an expressway including a toll gate, the speed threshold Ths includes a speed threshold Thp calculated by the following calculation formula. .
Thp = 3.6 × L / {Tp + 3.6 × L / Vp}
Tp (seconds): general stopping time when the vehicle stops at the toll booth Vp (km / h): speed generally assumed when the vehicle passes through the highway section including the toll booth

According to the congestion degree determination device of the present embodiment, the congestion degree of the link is determined based on the speed threshold Thp, which uses the general stop time Tp when the vehicle stops at the toll booth as the stop factor term TS.
For this reason, the congestion degree of the link corresponding to the section of the expressway including a toll gate can be determined more accurately.

(8) The congestion degree determination method of the present embodiment is a determination method executed by the above-described congestion degree determination apparatuses (1) to (7).
Therefore, the congestion degree determination method of this embodiment has the same effects as the congestion degree determination apparatuses (1) to (7) described above.

(9) The computer program of the present embodiment is a computer program for causing a computer to function as the above-described congestion degree determination device (1) to (7).
Therefore, the computer program of this embodiment has the same operational effects as the above-described congestion degree determination devices (1) to (7).

<Details of Embodiment of the Present Invention>
Hereinafter, details of embodiments of the present invention will be described with reference to the drawings. In addition, you may combine arbitrarily at least one part of embodiment described below.

〔Definition of terms〕
In describing the details of the present embodiment, first, terms used in this specification are defined.
“Vehicle” means all vehicles traveling on the road. Therefore, in addition to automobiles, light vehicles, and trolley buses, motorcycles are also vehicles.
In the present embodiment, the simple term “vehicle” includes both a probe vehicle having an in-vehicle device capable of transmitting probe information and a normal vehicle not having the in-vehicle device.

“Probe information”: Various information related to the vehicle sensed by the probe vehicle traveling on the road. The probe information is also referred to as probe data or floating car data. The probe information includes various types of vehicle data such as probe vehicle identification information, vehicle position, vehicle speed, vehicle direction, and time of occurrence thereof.
“Probe vehicle”: A vehicle that senses probe information and transmits it to the outside. Vehicles traveling on the road include both probe vehicles and other vehicles.

“Cycle length”: The time of one cycle from the blue (or red) start time of a traffic signal to the next blue (or red) start time.
“Blue time zone”: A time zone in which the vehicle has the right of traffic at the intersection. The end time of the blue time zone may be set to the end time of the blue time at the earliest time and the end time of the yellow time at the latest time. In the case of an intersection with an arrow lamp, it may be the end point of the right turn arrow.

“Queue”: A queue of vehicles that are stopped in front of an intersection due to waiting for a traffic light with a red light.
“Stop wave”: When a red signal is generated, a signal queue is generated, and the length of the queue increases with time. A transmission wave that increases the queue length is called a stop wave.

“Starting wave”: When the signal is switched to a green light during the generation of the signal queue, the vehicle starts to start in order from the vehicle in front of the intersection. A transmission wave when the signal waiting vehicle starts is called a start wave.
“Starting wave velocity”: Refers to the propagation velocity of the starting wave. That is, it is the slope of the linear function when the starting wave delay is defined by a linear function of the vehicle stop position.

“Link”: A road section having an upward or downward direction that connects nodes such as an intersection.
A link in a direction flowing into the intersection as viewed from a certain intersection is referred to as an inflow link, and a link in a direction flowing out from the intersection as viewed from a certain intersection is referred to as an outflow link. An intersection corresponding to a node on the downstream side of the inflow link is referred to as a “terminal intersection”.

“Link travel time”: Travel time when the road section of the travel time calculation unit is “link”, that is, travel time required for the vehicle to travel from the start to the end of one link. .
“Link average speed”: A speed obtained by dividing the link travel time by the link length.

“Congestion degree”: An index indicating the degree of congestion of vehicles on a link. For example, in this embodiment, the degree of congestion on the link is divided into three categories: “smooth”, “congested”, and “congested”.
“Smooth” means a situation in which a terminal intersection can be passed without waiting for a signal, and a situation in which a queue at the terminal intersection can be made in one green light time.

“Crowded” refers to a situation in which the queue at the end intersection does not make money in the first green light time but makes money in the second green light time.
“Congestion” refers to a situation where the queue at the end intersection does not make money even during the second green light period. The congestion degree may be identified by a level value or the like. In this case, for example, smoothness may be defined as level 0, congestion as level 1, and congestion as level 2.

[Overall system configuration]
FIG. 1 is an overall configuration diagram of an information providing system 1 according to an embodiment of the present invention. FIG. 2 is a block diagram of the information providing device 2 and the in-vehicle device 4 included in the information providing system 1.
As shown in FIGS. 1 and 2, the information providing system 1 includes an information providing device 2 that is a kind of server installed in a data center and the like, and an in-vehicle device 4 of a plurality of probe vehicles 3 that communicate with the information providing device 2. Etc.

As will be described later, the information providing apparatus 2 of the present embodiment functions as a “congestion degree determination apparatus”.
The function of this determination device includes processing for calculating the link average speed using the probe information as original data, and comparing the calculated link average speed with a predetermined speed threshold value, so that the congestion of the link corresponding to the road on which the probe vehicle passes A process for determining the degree is included.

In the information providing system 1 of the present embodiment, the information providing apparatus 2 collects probe information including the vehicle position and its passing time from each probe vehicle 3, and calculates the link travel time and link congestion degree calculated from the collected probe information. Such a traffic information is distributed to the in-vehicle device 4 of the probe vehicle 3, the user terminal 6 of the other user 5, and the like.
The information providing apparatus 2 of the present embodiment is a computer apparatus operated by a manufacturer of the vehicle 3 or an IT company that performs various information providing businesses. The information providing device 2 may be either an on-premises server or a cloud server.

The in-vehicle device 4 of the probe vehicle 3 can wirelessly communicate with wireless base stations 7 (for example, mobile base stations) in various places. The radio base station 7 can communicate with the information providing apparatus 2 via a public communication network 8 such as the Internet.
Therefore, the in-vehicle device 4 can wirelessly transmit the uplink information S1 addressed to the information providing device 2 to the wireless base station 7. The information providing apparatus 2 can transmit the downlink information S2 addressed to the specific in-vehicle apparatus 4 to the public communication network 8.

The user terminal 6 of the user 5 includes a data communication terminal possessed by the user 5 such as a smartphone, a tablet computer, or a notebook computer. The user terminal 6 can wirelessly communicate with wireless base stations 7 in various places.
Therefore, the user terminal 6 can wirelessly transmit the uplink information S1 addressed to the information providing apparatus 2 to the wireless base station 7. The information providing apparatus 2 can transmit downlink information S2 addressed to a specific user terminal 6 to the public communication network 8.

1 and 2 exemplify a user terminal 6 composed of a mobile terminal, the user terminal 6 may be a computer device such as a desktop personal computer installed indoors.
In this case, the user terminal 6 communicates with the information providing apparatus 2 via a fixed communication network that communicates with the public communication network 8 through an optical communication line or the like.

[Configuration of Information Providing Device]
As illustrated in FIG. 2, the information providing apparatus 2 includes a server computer 10 including a workstation and various databases 21 to 24 connected to the server computer 10. The server computer 10 includes an information processing unit 11, a storage unit 12, and a communication unit 13.
The storage unit 12 includes a storage including at least one nonvolatile memory (storage medium) of HDD (Hard Disk Drive) and SSD (Solid State Drive) and a volatile memory (storage medium) including a random access memory. Device.

The information processing unit 11 includes an arithmetic processing unit including a CPU (Central Processing Unit) that reads a computer program 14 stored in a nonvolatile memory of the storage unit 12 and performs information processing according to the program 14.
The computer program 14 of the information providing apparatus 2 includes a program that causes the information processing unit 11 to generate predetermined traffic information such as a link travel time calculation process and a congestion degree determination process for each link.

The communication unit 13 is a communication interface that communicates with the radio base station 7 via the public communication network 8. The communication unit 13 can receive the uplink information S1 transmitted from the wireless base station 7 to the own device, and can transmit the downlink information S2 generated by the own device to the wireless base station 7.
The communication unit 13 may be connected to the central device 15 of the traffic control center via a predetermined dedicated line 16. The central device 15 is a server computer that comprehensively determines signal control parameters for intersections included in a predetermined traffic control area.

The databases 21 to 24 are large-capacity storages including HDDs or SSDs that are connected to the server computer 10 so as to be able to transfer data.
The databases 21 to 24 include a map database 21, a probe database 22, a member database 23, and a signal information database 24.

In the map database 21, road map data 25 covering the country is recorded. The road map data 25 includes “intersection data” and “link data”.
“Intersection data” is data in which an intersection ID assigned to an intersection in Japan is associated with position information of the intersection. The “link data” includes data in which the following information 1) to 4) is associated with the link ID of a specific link assigned corresponding to a domestic road.

Information 1) Position information of start point / end point / interpolation point of specific link Information 2) Link ID connected to start point of specific link
Information 3) Link ID connected to the end point of a specific link
Information 4) Link cost of specific link

The road map data 25 constitutes a network corresponding to the actual road alignment and the road traveling direction. For this reason, the road map data 25 is a network in which road sections between nodes representing intersections are connected by a directed link l (lowercase letter L).
Specifically, the road map data 25 includes a directed graph in which a node n is set for each intersection and each node n is connected by a pair of directed links 1 in the opposite direction. Therefore, in the case of a one-way road, the node n is connected only to the directional link 1 in one direction.

  The road map data 25 includes road type information indicating whether a specific directed link 1 corresponding to each road on the map is a general road or a toll road, and a tollgate included in the directed link 1 Alternatively, facility information indicating the type of facility such as a parking area is also included.

In the probe database 22, probe information received from the probe vehicle 3 registered in advance in the information providing apparatus 2 is accumulated for each identification information of the vehicle 3.
The accumulated probe information includes at least the vehicle position and its passing time, but other vehicle data such as the vehicle speed and the vehicle direction may be accumulated. The sensing period of the probe information by the probe vehicle 3 is a granularity that can identify the travel history of the probe vehicle 3, and is, for example, 1 second.

The member database 23 includes at least one of personal information such as the registered member's (user 5) address and name, and identification information of the registered member's user terminal 6 (for example, MAC address, mail address, telephone number, etc.). ) Is included.
In the signal information database 24, the cycle length of each intersection, the time length of the blue time zone, and the like are accumulated for each directed link l.

The information processing unit 11 records, in the signal information database 24, the intersection cycle length and the blue time zone length received at predetermined intervals for the intersection provided with information from the central device 15.
The information processing unit 11 records, in the signal information database 24, a predetermined cycle length and a time length of a blue time zone that are determined in advance according to the size of the intersection and the like for the intersection that is not provided with information from the central device 15.

[Configuration of in-vehicle device]
As shown in FIG. 2, the in-vehicle device 4 includes a computer device that includes a processing unit 31, a storage unit 32, a communication unit 33, and the like.
The processing unit 31 includes an arithmetic processing unit that includes a CPU and an ECU (Electric Control Unit) that read a computer program 34 stored in a nonvolatile memory of the storage unit 32 and performs various types of information processing according to the program 34.

The storage unit 32 is a storage device that includes at least one nonvolatile memory (storage medium) of the HDD and the SSD and a volatile memory (storage medium) including a random access memory.
The computer program 34 of the in-vehicle device 4 includes an operation control program to be executed by the ECU of the processing unit 31, a route search program for the probe vehicle 3, and an image processing program for displaying the search route on the display of the navigation device.

The communication unit 33 includes a wireless communication device that is permanently mounted on the probe vehicle 3 or a data communication terminal (for example, a smartphone, a tablet computer, or a node personal computer) that is temporarily mounted on the probe vehicle 3. .
The communication unit 33 has a GPS (Global Positioning System) receiver. The processing unit 31 monitors the current position of the host vehicle almost in real time based on the GPS position information received by the communication unit 33.

The processing unit 31 measures vehicle data such as the vehicle position, the vehicle speed, the vehicle direction, and the CAN information of the host vehicle every predetermined sensing period (for example, 1 second), and records it in the storage unit 12 together with the measurement time.
When the vehicle data is accumulated in the storage unit 12 for a predetermined recording time (for example, 5 minutes), the communication unit 33 generates probe information including the accumulated vehicle data and identification information of the own vehicle. The probe information is uplink transmitted to the information providing apparatus 2.

  The in-vehicle device 4 of the vehicle 3 includes an input interface (not shown) that receives a driver's operation input. The input interface includes, for example, an input device attached to the navigation device or an input device of a data communication terminal mounted on the probe vehicle 3.

[Average stop time by waiting for traffic lights]
FIG. 3 is a graph showing the relationship between the queue at the intersection and the traveling locus of the vehicle.
In FIG. 3, the horizontal axis represents time (seconds), and the vertical axis represents the distance (m) from the intersection stop line. “C”, “G”, and “R” represent the cycle length, the blue time zone, and the red time of the intersection, respectively. As described above, the end time of the blue time zone may be any of the end time of the blue time, the end time of the yellow time, and the end time of the right turn arrow.

In FIG. 3, a substantially triangular area with vertical hatching is a “queue” formed by red signals in one cycle. An inclined side SL on the left side of this area in the figure is a stop position of the vehicle that has entered the queue.
As shown in “Vehicle travel trajectory” in FIG. 3, the vehicle that has entered the terminal intersection first stops at the end of the queue extending from the vicinity of the red start time (which may include a yellow signal).

An inclined side SR on the right side of the triangular area in the figure represents a start position of a vehicle that turns green and starts from an intersection. When it turns green, the vehicle starts from the top of the queue.
Each of the stop position and the start position has a propagation velocity that extends upstream with time. The inclined sides SL and SR having the inclination of the propagation speed are the above-mentioned “stop wave” and “starting wave”.

Here, assuming that the saturation traffic flow rate at the terminal intersection is Sf (units / second), the maximum traffic volume Q that can pass through the terminal intersection in one or less signal streets, that is, one blue time zone G can be obtained. The maximum traffic volume Q (unit / second) per cycle is calculated by the following equation.
Q = (G / C) × Sf

Further, the total stop time DL of all vehicles arriving at the terminal intersection is calculated by the following equation.
DL = (1/2) × {(CG) × Q × C}
= (1/2) * {(CG) * (G / C) * Sf * C}
= (1/2) * {(CG) * G * Sf}

Since the traffic volume passing through the terminal intersection in one green time zone G is G × Sf, the average stop time dL per vehicle is calculated by the following equation. That is, the average stop time required when one vehicle passes the terminal intersection is half of the red time G of the intersection.
dL = DL / (G × Sf)
= (1/2) × (CG)
= (1/2) x R

[Problems of conventional congestion level judgment processing]
The conventional congestion degree determination process using the link travel time based on the probe information includes the following steps 1 to 3.
1) Step 1: Link travel time calculation step Step 1 is a step of calculating the link travel time TT (seconds) using the probe information stored in the probe database 22. Specifically, the link travel time TT is calculated by the calculation formula of TT = te−ts, where ts is the start end passage time of the link of the probe vehicle 3 and te is the end passage time of the link of the probe vehicle 3.

2) Step 2: Link average speed calculation step Step 2 calculates the link average speed Vm (km / h) of the probe vehicle 3 by dividing the link length L (m) by the link travel time TT (seconds). It is a process to do. Specifically, the link average speed Vm of the probe vehicle 3 is calculated by a calculation formula of Vm = 3.6 × L / TT.

3) Step 3: Judgment degree determination step Step 3 is a step of judging the degree of congestion of the link by comparing the calculated link average speed Vm with predetermined threshold values Th1 and Th2. Here, two types of threshold values Th1 and Th2 are adopted, for example, Th1 = 20 (km / h) and Th2 = 10 (km / h).
The threshold value Th1 is a threshold value that represents a boundary between smooth and congestion, and the threshold value Th2 is a threshold value that represents a boundary between congestion and congestion. Therefore, the degree of congestion of the link is determined as follows according to the magnitude relationship with respect to the threshold values Th1 and Th2 of the link average speed Vm.

When Vm <Th2: The link is determined as “congested” (level 2) When Th2 ≦ Vm <Th1: The link is determined as “congested” (level 1) When Th1 ≦ Vm: The link is “smooth” (level 0) )

FIG. 4 is a graph showing the relationship between the link length L and the link average speed Vm.
The first speed Va represents the link average speed Vm when it is assumed that the probe vehicle 3 stops for an average stop time (= (1/2) × (CG)) at the end intersection.
The second speed Vb represents the link average speed Vm when it is assumed that the probe vehicle 3 stops immediately before the red signal at the terminal intersection (when it is assumed that the probe vehicle 3 stops from the start to the end of the red time R).

As shown in FIG. 4, the first and second speeds Va. Vb is calculated as follows.
Va = 3.6 * L / {(1/2) * (CG) + 3.6 * L / V}
Vb = 3.6 × L / {(CG) + 3.6 × L / V}
The first term (= (1/2) × (CG)) in the braces of the first speed Va is the average stop time at the end intersection. The first term (= (CG)) in the braces of the second speed Vb is a stop time when stopping immediately before the red signal at the end intersection.

Each curve of the first and second speeds Va and Vb in FIG. 4 shows the relationship between the link length L and the average link speed Vm when C = 120 seconds, G = 50 seconds, and V = 50 km / h. To express.
As shown by the curve Va in FIG. 4, when the link average speed Vm of the probe vehicle 3 is the first speed Va, when the link length L is about 300 m or less, Va <Th1 (= 20 km / h) and the link length L Becomes about 100 m or less, Va <Th2 (= 10 km / h).

  In this case, the probe vehicle 3 actually passes the link at V = 50 km / h, stops for an average stop time before the intersection, and then can pass the terminal intersection after waiting for one signal (that is, In the case where “smooth” is to be determined), “congestion” is determined when the link length L is about 300 m or less, and “congestion” is determined when the link length L is about 100 m or less.

  As shown by the curve Vb in FIG. 4, when the link average speed Vm of the probe vehicle 3 is the second speed Vb, when the link length L is about 650 m or less, Vb <Th1 (= 20 km / h) and the link length L Becomes about 250 m or less, Vb <Th2 (= 10 km / h).

  In this case, the probe vehicle 3 actually passes the link at V = 50 km / h, stops for the red time before the intersection, and then can pass the terminal intersection after waiting for one signal (that is, Even when the link length L is about 650 m or less, it is determined as “congested”, and when the link length L is about 250 m or less, it is determined as “congestion”.

Thus, the link average speed Vm decreases as the distance becomes shorter due to the influence of the stop time ((1/2) × R or R) due to the signal waiting at the intersection.
For this reason, in the method of comparing the link average speed Vm calculated from the probe information with the fixed threshold values Th1 and Th2, in determining the degree of traffic congestion of a link having a relatively short link length L, actually, it is necessary to wait for one signal at the intersection. There are cases in which it is erroneously determined to be “congested” or “congested” even though it is a “smooth” traffic situation that only occurs.

  Therefore, in this embodiment, by adopting the speed threshold value Thk defined by the calculation formula that varies according to the link length L, the determination of the degree of congestion using the link average speed Vm using the probe information as the original data is further performed. I was able to do it accurately. Hereinafter, the congestion degree determination process performed by the information providing apparatus 2 of the present embodiment will be described.

[Congestion level judgment processing of this embodiment]
FIG. 5 is a flowchart illustrating an example of the congestion degree determination process executed by the information processing unit 11 of the information providing apparatus 2.
The information processing unit 11 of the information providing apparatus 2 executes the congestion degree determination process shown in the flowchart of FIG. 5 every predetermined control period (for example, 10 minutes), and the determination result of the congestion degree regarding each link for each control period. (Smooth or traffic jam) is output.

As shown in FIG. 5, the information processing unit 11 of the information providing device 2 first calculates the link travel time TT of the probe vehicle 3 using the probe information stored in the probe database 22 in the current control cycle ( Step ST11).
Specifically, assuming that the start passage time of the link of the probe vehicle 3 is ts and the end passage time of the link of the probe vehicle 3 is te, the information processing unit 11 sets the link travel time TT to TT = te−ts. Calculate with the formula.

  In the calculation process of step ST11, in the case of a link in which traveling tracks of a plurality of probe vehicles 3 exist, a statistical value such as an average value or a median value of the link travel times of the plurality of probe vehicles 3 is used as the link travel time TT. Adopt it.

Next, the information processing section 11 calculates the link average speed Vm of the probe vehicle 3 (step ST12).
Specifically, the information processing unit 11 calculates the link average speed Vm (km / h) of the probe vehicle 3 by dividing the link length L (m) by the link travel time TT (seconds). That is, the information processing unit 11 calculates the link average speed Vm of the probe vehicle 3 by a calculation formula of Vm = 3.6 × L / TT.

Next, the information processing section 11 calculates a speed threshold Th (k) for each link for a plurality of links for which the average link speed Vm is obtained (step ST13). When the link is a general road, the equation for calculating the speed threshold Th (k) is as the following equation (1).
Th (k) = 3.6 × L / {(k × CG) + 3.6 × L / Vo} (1)
In the above calculation formula (1), “k” means the number of cycles that a vehicle stopped in front of the end intersection with a red signal waits before passing the intersection.

In the above calculation formula (1), Vo (km / h) is a speed generally assumed when the vehicle travels on a general road. For example, Vo may be a legal speed. In the case of a road whose actual speed is known, Vo may be the actual speed.
Moreover, it is good also considering Vo as a different value according to the road width. In this case, for example, Vo = 60 km / h for a link corresponding to a national road, and Vo = 30 km / h for a link corresponding to another small road.

Vo may be a different value depending on the presence or absence of speed regulation. For example, in the case of a road in which a regulated speed in a predetermined time zone or period is specified, the regulated speed may be adopted within the time zone or period, and the legal speed may be set outside the time zone or period.
Further, in the case of a road section that includes a regulated section where a regulated speed exists, a regulated speed may be adopted for a link included in the regulated section, and a legal speed may be adopted for a link that is not included in the regulated section. .

In the above calculation formula (1), (k × CG) on the right side is a stop time when a vehicle that stops in front of the end intersection with a red signal passes through the end intersection with the kth green signal.
Therefore, the term {(k × CG) + 3.6 × L / Vo} on the right-hand side indicates that a vehicle traveling at a predetermined assumed speed Vo encounters a red signal at the terminal intersection and the terminal intersection at the k-th green signal. Means the maximum link travel time when going through.

In the present embodiment, two types of threshold values Th (1) and Th (2) are employed, in which the value of k (times) in the calculation formula (1) is 1 and 2, respectively.
The threshold value Th (1) is a threshold value that represents a boundary between smooth and congestion, and the threshold value Th (2) is a threshold value that represents a boundary between congestion and traffic jam. As shown in FIG. 5, the calculation formulas of the two threshold values Th (1) and Th (2) are as shown in the following formulas (2) and (3), respectively.

Th (1) = 3.6 × L / {(CG) + 3.6 × L / Vo} (2)
However, the maximum value of Th (1) is 20 (km / h). That is, when the calculated value of the expression (2) exceeds 20 (km / h), the peak is reached at 20 (km / h).
Th (2) = 3.6 × L / {(2 × CG) + 3.6 × L / Vo} (3)
However, the maximum value of Th (2) is 10 (km / h). That is, when the calculated value of the expression (3) exceeds 10 (km / h), the peak is reached at 10 (km / h).

In the calculation formula (2), {(CG) + 3.6 × L / Vh} on the right side indicates that a vehicle traveling at a predetermined assumed speed Vo encounters a red signal at the terminal intersection and terminates at the first green signal. It means the maximum link travel time when crossing an intersection.
Therefore, when the link average speed Vm is equal to or greater than Th (1), it can be estimated that the link traveled by the probe vehicle 3 is “smooth”, and when the link average speed Vm is less than Th (1), the probe It can be estimated that the link on which the vehicle 3 traveled is “crowded”.

In the calculation formula (3), {(2 × CG) + 3.6 × L / Vh} on the right side indicates that a vehicle traveling at a predetermined assumed speed Vo encounters a red signal at the terminal intersection and is the second green signal. This means the maximum link travel time when passing through a terminal intersection.
Accordingly, when the link average speed Vm is equal to or greater than Th (2), the link traveled by the probe vehicle 3 can be estimated as “non-congested”, and when the link average speed Vm is less than Th (2), the probe vehicle It can be estimated that the link traveled by 3 is “traffic jam”.

The reason for defining the maximum value of Th (1) is as follows. That is, when the link length L is sufficiently larger than 3.6 × L / Vo than (CG), the value of the speed threshold Th (1) becomes excessive, and it is erroneously determined to be congested although it is smooth. This is because there is a high possibility that
The reason for defining the maximum value of Th (2) is also the same. In other words, when the link length L is sufficiently larger than 3.6 × L / Vo than (2 × CG), the value of the speed threshold Th (2) becomes excessive, and traffic jams occur even though there is no traffic jam. This is because the possibility of erroneous determination increases.

  Next, the information processing section 11 compares the link average speed Vm with the speed thresholds Th (1) and Th (2) to determine the degree of congestion of the link (step ST14). Specifically, the information processing unit 11 determines the degree of link congestion as follows according to the magnitude relationship of the link average speed Vm with respect to the threshold values Th (1) and Th (2).

When Vm <Th (2): The link is determined as “congested” (level 2) When Th (2) ≦ Vm <Th (1): The link is determined as “congested” (level 1) Th (1) ≦ In case of Vm: Judge the link as “smooth” (level 0)

When the information processing unit 11 of the information providing apparatus 2 determines the congestion level of each link by the congestion level determination process of FIG. 5, the determination result is distributed to the in-vehicle device 4 and the user terminal 6.
Specifically, the information processing unit 11 generates traffic information including a link identification number and a determination result (smooth, congestion, or traffic jam) of the link, and downloads the generated traffic information to the in-vehicle device 4 and the user terminal 6. Send link.

When the road map is displayed on the display of the navigation device of the host vehicle, the processing unit 31 of the in-vehicle device 4 that has received the traffic information displays the road in a different display mode according to the determination result for each link. This also applies to the user terminal 6.
For example, when the smoothness is defined as blue, the congestion is yellow, and the congestion is defined as red, the processing unit 31 displays the road corresponding to the smooth link in blue and displays the road corresponding to the busy link in yellow. The display is controlled so that the road corresponding to the traffic jam link is displayed in red.

[First Modification]
In the above-described embodiment, two speed thresholds Th (1) and Th (2) are adopted to determine whether the link is smooth, congested, or congested. However, any one speed threshold Th ( Only 1) and Th (2) may be adopted.

Specifically, only the speed threshold Th (1) may be adopted to determine whether the link is smooth or congested, or only the speed threshold Th (2) may be adopted to prevent the link from being You may determine whether it is a traffic jam or a traffic jam.
In the above-described embodiment, the speed threshold Th (3) where k = 3 may be further adopted, and the link congestion degree may be classified into four types according to the three speed thresholds Th (1) to Th (3).

In this case, the information processing unit 11 of the information providing apparatus 2 may determine the degree of congestion of the link as follows according to the magnitude relationship with respect to the threshold values Th (1) to Th (3) of the link average speed Vm.
When Vm <Th (3): Determined as “super traffic jam” (level 3) When Th (3) ≦ Vm <Th (2): Determined as “traffic jam” (level 2) Th (2) ≦ Vm <Th For (1): Determined as “congested” (level 1) When Th (1) ≦ Vm: Determined as “smooth” (level 0)

[Second Modification]
In the above-described embodiment, the case of determining the degree of traffic congestion of a “general road” link where a traffic signal is present at an intersection has been illustrated, but the link may be a “highway” link.
For example, in the case of a link corresponding to a section of an expressway connected to a service area or a parking area (hereinafter abbreviated as “area”), the vehicle is used as a stop factor term that increases the link travel time TT of the probe vehicle 3 What is necessary is just to consider stop time Tr (second) (for example, 1800 to 3600 seconds) generally assumed when the driver | operator of a person takes a break in an area.

In other words, in the case of a link corresponding to a section of an expressway connected to an area, the congestion level of the link may be determined using the speed threshold Thr defined by the following calculation formula (4).
Thr = 3.6 × L / {Tr + 3.6 × L / Vr} (4)
In the above calculation formula (4), Vr (km / h) is a speed (for example, 80 km / h) generally assumed when a vehicle passes through a section of an expressway connected to an area.

In this case, the information processing unit 11 of the information providing device 2 may determine the degree of congestion on the highway link as follows according to the magnitude relationship of the average link speed Vm with respect to the threshold Thr.
When Vm <Thr: The link is determined as “unsmooth (congested)” (level 1) When Thr ≦ Vm: The link is determined as “smooth” (level 0)

  Similarly, in the case of a link corresponding to a section of an expressway including a toll booth, a general stop time when the vehicle stops at the toll booth as a stop factor term that increases the link travel time TT of the probe vehicle 3. Tp (seconds) (for example, 10 to 30 seconds) may be considered.

That is, in the case of a link corresponding to a section of an expressway including a toll gate, the degree of link congestion may be determined using the speed threshold Thp defined by the following calculation formula (5).
Thp = 3.6 × L / {Tp + 3.6 × L / Vp} (5)
In the above calculation formula (5), Vp (km / h) is a generally assumed speed (for example, 80 km / h) when a vehicle passes through a section of an expressway including a toll gate.

In this case, the information processing unit 11 of the information providing apparatus 2 may determine the congestion degree of the highway link as follows according to the magnitude relationship of the average link speed Vm with respect to the threshold Thp.
When Vm <Thp: The link is determined as “unsmooth (congested)” (level 1) When Thp ≦ Vm: The link is determined as “smooth” (level 0)

[Generalization of speed threshold calculation formula]
When the cases of both general roads and highways are combined, the speed threshold Ths used for determining the degree of congestion of the link can be generalized as in the following equation (6).
Ths = 3.6 × L / {TS + 3.6 × L / VS} (6)
However, TS (seconds) is a “stop factor term” that occurs before the probe vehicle 3 passes the link. VS (km / h) is a speed generally assumed when a vehicle travels on a road.

In this case, the information processing unit 11 of the information providing apparatus 2 may set the stop factor term TS and the assumed speed VS as follows according to whether the link is a general road or a highway.
1) When the link corresponds to a general road The stop factor term TS is set to (k × CG). The stop factor term (k × CG) (seconds) is a stop time when a vehicle stopped at a red signal at the terminal intersection passes through the terminal intersection at the kth green signal.
Assume that the assumed speed VS is Vo. The assumed speed Vo (km / h) is a speed generally assumed when the vehicle travels on a general road (for example, legal speed or actual speed).

2) When the link corresponds to a section of an expressway that connects to the area The stop factor TS is Tr. The stop factor term Tr (seconds) is a stop time generally assumed when the driver of the vehicle takes a break in the area.
Assume that the assumed speed VS is Vr. The assumed speed Vr (km / h) is a speed generally assumed when a vehicle passes through a section of an expressway connected to an area.

3) When the link corresponds to the section of the expressway including the toll gate The stop factor term TS is Tp. The stop factor term Tp (seconds) is a general stop time when the vehicle stops at the toll gate.
Assume that the assumed speed VS is Vr. The assumed speed Vp (km / h) is a speed generally assumed when a vehicle passes through a section of an expressway including a toll gate.

[Other variations]
The above-described embodiments (including modifications) are illustrative and non-restrictive in every respect. The scope of the right of the present invention includes all modifications within the scope equivalent to the configurations described in the claims.

1 Information providing system 2 Information providing device (congestion level judging device)
DESCRIPTION OF SYMBOLS 3 Probe vehicle 4 In-vehicle apparatus 5 User 6 User terminal 7 Wireless base station 8 Public communication network 10 Server computer 11 Information processing part 12 Storage part 13 Communication part 14 Computer program 15 Central apparatus 16 Dedicated line 21 Map database 22 Probe database 23 Member database 24 Information Database 25 Road Map Data 31 Processing Unit 32 Storage Unit 33 Communication Unit 34 Computer Program

Claims (9)

A device for determining the degree of congestion of a link corresponding to a road,
A communication unit for receiving probe information from the probe vehicle;
A link average speed of the probe vehicle is calculated using the received probe information, and a degree of congestion of a link corresponding to a road on which the probe vehicle passes is determined by comparing the calculated link average speed with a speed threshold. An information processing unit for
The speed threshold used by the information processing unit is a congestion degree determination device including a speed threshold Ths calculated by the following calculation formula.
Ths = 3.6 × L / {TS + 3.6 × L / VS}
L (m): Link length TS (seconds): Stop factor term (seconds) that occurs before the probe vehicle passes the link
VS (km / h): the speed assumed when the vehicle travels on the road If the link corresponds to a general road,
The traffic speed determination device according to claim 1, wherein the speed threshold Ths is composed of a speed threshold Th (k) calculated by the following calculation formula.
Th (k) = 3.6 × L / {(k × CG) + 3.6 × L / Vo}
k (times): The number of cycles that a vehicle stopped in front of the end intersection with a red light will wait until it passes through the intersection C (seconds): cycle length of the end intersection G (seconds): blue time zone at the end intersection Time length Vo (km / h): speed assumed when a vehicle travels on a general road The speed threshold Th (k) includes
The congestion degree determination device according to claim 2, wherein at least one of a first threshold value Th (1) when k = 1 and a second threshold value Th (2) when k = 2 is included. A predetermined maximum value is set for the first and second threshold values Th (1) and Th (2).
The information processing unit
The congestion degree determination device according to claim 3, wherein when the calculated values of the first and second threshold values Th (1) and Th (2) exceed the maximum value, the maximum value is set as the speed threshold value. The assumed speed Vo is
The congestion degree determination device according to any one of claims 2 to 4, wherein the congestion degree determination device is set to a different value according to at least one of a road width of the general road and presence / absence of speed regulation. When the link corresponds to a section of a highway that leads to a service area or a parking area,
The traffic speed determination device according to any one of claims 1 to 5, wherein the speed threshold Ths includes a speed threshold Thr calculated by the following calculation formula.
Thr = 3.6 × L / {Tr + 3.6 × L / Vr}
Tr (seconds): Stopping time generally assumed when a vehicle driver takes a break in the area Vr (km / h): Generally assumed when a vehicle passes through a section of a highway connected to the area Speed If the link corresponds to a highway section that includes a toll gate,
The traffic speed determination device according to any one of claims 1 to 6, wherein the speed threshold Ths includes a speed threshold Thp calculated by the following calculation formula.
Thp = 3.6 × L / {Tp + 3.6 × L / Vp}
Tp (seconds): general stopping time when the vehicle stops at the toll booth Vp (km / h): speed generally assumed when the vehicle passes through the highway section including the toll booth A method for determining the degree of congestion of a link corresponding to a road,
A first step of receiving probe information from the probe vehicle;
A link average speed of the probe vehicle is calculated using the received probe information, and a degree of congestion of a link corresponding to a road on which the probe vehicle passes is determined by comparing the calculated link average speed with a speed threshold. A second step of,
The speed threshold used in the second step is a congestion degree determination method including a speed threshold Ths calculated by the following calculation formula.
Ths = 3.6 × L / {TS + 3.6 × L / VS}
L (m): Link length TS (seconds): Stop factor term (seconds) that occurs before the probe vehicle passes the link
VS (km / h): the speed assumed when the vehicle travels on the road A computer program for causing a computer to function as a device for determining the degree of congestion of a link corresponding to a road,
In the computer,
A first step of receiving probe information from the probe vehicle;
A link average speed of the probe vehicle is calculated using the received probe information, and a degree of congestion of a link corresponding to a road on which the probe vehicle passes is determined by comparing the calculated link average speed with a speed threshold. And a second step of performing
The speed threshold used in the second step is a computer program comprising a speed threshold Ths calculated by the following calculation formula.
Ths = 3.6 × L / {TS + 3.6 × L / VS}
L (m): Link length TS (seconds): Stop factor term (seconds) that occurs before the probe vehicle passes the link
VS (km / h): the speed assumed when the vehicle travels on the road

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