JP2013235430A - Travel time calculation device and method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately calculate a travel time even when an amount of data of probe information is small.SOLUTION: This invention relates to a device that calculates travel times TL and TS when a vehicle travels on road sections Li and Sj. The calculation device includes: an acquisition unit (a storage unit 12) that acquires probe information of one or a plurality of probe vehicles 1 traveling on the road sections Li and Sj, section lengths DL and DS of the road sections Li and Sj, and signal control parameters of intersections of the road sections Li and Sj; and a data processing unit 11 that estimates actual speed VSm of the road sections Li and Sj on the basis of the acquired probe information and calculates travel times TL and TS of the road sections Li and Sj from the estimated actual speed VSm, the acquired section lengths DL and DS and signal control parameters.

Description

  The present invention relates to an apparatus and method for calculating travel time when a vehicle passes through a road section, and a computer program for causing a computer to execute the calculation process.

An information providing service for calculating a time (travel time) required for a vehicle to pass through a predetermined road section and providing the result to the driver of the vehicle has already been performed.
The travel time is generally estimated based on the observed traffic situation data (number of vehicles, passage time, etc.) by observing the traffic situation at a plurality of predetermined positions with a vehicle detector installed on the road. . However, in this estimation method, in order to provide the driver with a wide range of travel time, it is necessary to install a large number of vehicle detectors, and there is a problem that the cost burden increases.

Therefore, a probe vehicle capable of transmitting probe information (travel locus information) including position, speed, time, and the like is actually traveled on a road section, and travel time is calculated using probe information received from the probe vehicle. The method has already been done.
The travel time using the probe information is usually based on the time and end point when the probe vehicle passes the start point of the road section by associating the vehicle position collected at a predetermined cycle (for example, 1 second) with the road section (for example, link). It is calculated by the difference from the passing time (see Patent Document 1).

JP 2005-196232 A

In the above conventional travel time calculation method, since only one probe information has a large error, the average value of travel time (average travel time) based on a plurality of probe information obtained in the same time zone is calculated as the road section. And travel time.
However, at present, since the number of probe vehicles is not so large, a large amount of probe information cannot be acquired for the same road section in the same time zone.

For this reason, even if the travel time consisting of the difference in transit time obtained from several probe vehicles is simply averaged, the average travel time varies greatly, and the average travel time deviates from the actual travel time. It may be time.
Particularly in a quiet time, a delay due to a signal waiting stop at an intersection may or may not be caused by the probe vehicle, and the variation in travel time obtained from the probe vehicle becomes so large that it cannot be ignored, and the accuracy of the average travel time is lowered.

  In view of the above-described conventional problems, an object of the present invention is to provide a travel time calculation device and the like that can accurately calculate travel time even when the number of probe information data is small.

  (1) The travel time calculation device according to the present invention acquires the probe information of one or more probe vehicles passing through a road section, the section length of the road section, and the signal control parameters of the intersection of the road section. A data processing unit that estimates the actual speed of the road section based on the acquired probe information, and calculates the travel time of the road section from the estimated actual speed and the acquired section length and signal control parameters; It is characterized by having.

According to the travel time calculation device of the present invention, the data processing unit estimates the actual speed of the road section based on the acquired probe information, and from the estimated actual speed, the acquired section length, and the signal control parameter, the road section Therefore, even when the number of probe information data is small, the travel time can be accurately calculated.
The reason is that the actual speed of the road section does not include the signal waiting element at the intersection and is mainly dependent on the road structure. This is because it can be accurately estimated from probe information and the like.

  (2) (3) In the travel time calculation device of the present invention, when the road section includes a link flowing into a predetermined intersection, the data processing unit calculates the estimated actual speed, the acquired link length, The link travel time required for travel of the link is calculated from the red time and cycle length of the intersection included in the acquired signal control parameter, the average signal waiting time at the intersection is calculated, and the calculated link travel time The link travel time of the link is calculated from the average signal waiting time.

Specifically, when the average signal waiting time at the intersection is Tw, the red time is R, and the cycle length is C, the data processing unit calculates the average signal waiting time Tw using the following equation.
Tw = R ² / 2C
In this case, the link travel time is a highly accurate time calculated from the actual speed, and the average signal waiting time can be calculated relatively accurately according to the above equation as long as the red time and cycle length of the intersection are known. The link travel time calculated from these times is also accurate.

  (4) In the travel time calculation device according to the present invention, when the road section includes a system section having a plurality of links in the sub-area under system control, the data processing unit estimates Assuming that the vehicle travels at a speed, the time required for the vehicle that departed from the start point of the system section to arrive at the end point of the system section is simulated, and a plurality of required results obtained as a result Based on the time, the section travel time of the system section is calculated.

  The reason is that in the case of the system section, there is a case where the signal is not waited at the intersection in the system section by the system control, so the link travel times of the links obtained in the above (2) and (3) are simply added up. It is more accurate to reflect the actual conditions of vehicle traffic in the system section than to calculate the section travel time based on the required time obtained by the above simulation, rather than using the section travel time of the system section. This is because a long section travel time can be obtained.

(5) In the travel time calculation device of the present invention, when the road section includes a route having a plurality of system sections having a plurality of links in a sub-area under system control and a boundary link connecting them. The data processing unit calculates the route travel time of the route based on the sum of the link travel time of the boundary link and the section travel times of the plurality of system sections.
The reason is that the system control is not performed at the boundary link, so that there is a high possibility of waiting for a signal, so the sum of the link travel time and the section travel time should be the route travel time.

(6) In the travel time calculation device of the present invention, when the delay time resulting from traffic congestion, excluding the stop time at the traffic light and the cruise time traveled at the actual speed, is defined as “stay time in traffic jam”, the data processing unit If the road section is not quiet, the travel time calculated in the above (2) to (5) plus the stay time in the traffic jam is taken as the travel time during the traffic congestion of the road section.
The reason for this is that the travel times (2) to (5) described above, which depend on the actual speed, are based on the assumption that the road section is quiet. This is because it can be considered that the travel time in (5) is further added with the stay time in a traffic jam.

  (7) Therefore, how to calculate the stay time in a traffic jam in a road section becomes a problem. Specifically, for example, when the road section is the link, the data processing unit adds the red time of the intersection to the quotient obtained by dividing the acquired link length by the estimated actual speed. The maximum link travel time of the link is calculated, and the stay time in the traffic jam of the link is calculated by subtracting the maximum link travel time during the quiet time from the actual link travel time of the probe vehicle.

The reason is that when the actual link travel time of the probe vehicle is obtained, if it is longer than the maximum link travel time during quiet periods, it can be estimated that traffic congestion has occurred in the link. .
(8) Therefore, in this case, the data processing unit determines whether or not the link is not quiet depending on whether or not the actually measured link travel time of the probe vehicle is larger than the maximum link travel time at the quiet time. be able to.

  (9) In addition, when the road section is the system section, the data processing unit sets the maximum time of the plurality of required times obtained as a result of simulation as the maximum section travel time in a quiet time, By subtracting the maximum section travel time during quiet periods from the actually measured section travel time of the probe vehicle, the stay time in the traffic congestion of the system section is calculated.

The reason is that when the actual travel time of the probe vehicle is obtained, and it is greater than the maximum travel time during quiet periods, it can be estimated that traffic congestion has occurred in the system section. is there.
(10) Therefore, in this case, the data processing unit determines whether or not the grid section is not quiet depending on whether or not the actually measured section travel time of the probe vehicle is larger than the maximum section travel time during the quiet time. It can be carried out.

(11) The travel time calculation method of the present invention is a calculation method performed by the device of the present invention described in the above (1) to (10). Therefore, the travel time calculation method of the present invention has the same effects as the device of the present invention described in the above (1) to (10).
(12) A computer program of the present invention causes a computer to execute the processing of the device of the present invention described in the above (1) to (10). Therefore, the computer program of the present invention has the same effects as the apparatus of the present invention described in the above (1) to (10).

  As described above, according to the present invention, it is possible to accurately calculate the travel time even when the number of probe information data is small.

It is the schematic which shows the whole structure of a traffic information processing system. It is a functional block diagram of a center apparatus. It is explanatory drawing which shows an example of the road area from which a data processing part calculates | requires travel time. It is a graph which shows the queue in front of an intersection, and the running locus of a vehicle. It is explanatory drawing which shows the simulation method of the section travel time of a system section.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
〔Definition of terms〕
In describing embodiments of the present invention, first, terms used in this specification will be defined.
“Vehicle”: General vehicle passing on the road, specifically, a vehicle in accordance with the Road Traffic Law. Vehicles under the law include automobiles, motorbikes, light vehicles and trolley buses. In the present embodiment, the term “vehicle” includes both a probe vehicle having an in-vehicle device capable of transmitting probe information and a vehicle not having the in-vehicle device.

“Vehicle sensor”: A roadside sensor that detects the presence of vehicles traveling on the road one by one at a fixed position. For example, an ultrasonic vehicle sensor that detects a vehicle passing directly below with an ultrasonic wave, a temperature-type vehicle sensor that detects the passage of a vehicle from a temperature change when the vehicle passes, or a vehicle that detects an inductance change A loop coil embedded in a road corresponds to this.
“Detection signal”: A pulse signal output when a vehicle detector installed at a predetermined position on a road detects one vehicle. Therefore, when a plurality of vehicles pass through the vehicle detector, sensing signals corresponding to each vehicle are output in time series.

“Probe information”: Various information related to the vehicle obtained from the in-vehicle device of the probe vehicle that actually travels on the road. Sometimes referred to as probe data or floating car data. This includes data such as vehicle ID, vehicle position, vehicle speed, vehicle orientation, and the time of occurrence thereof.
Since the vehicle speed can be calculated if the vehicle position and time are known, it is sufficient that the probe information includes the vehicle position and time. However, in order to calculate the actual speed described later more accurately, the vehicle speed is measured at a predetermined time. Preferably, the vehicle speed is included in the probe information.

“Signal control parameter”: generally refers to cycle length, split, and offset. In the present embodiment, at least red among timing information (start time and display time of each lamp color) for switching the signal lamp color at the intersection. Time (red start time and its display time) shall be included.
“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.

“Split”: The ratio of the time (green signal time, red signal time, etc.) allocated to each display to the cycle length.
“Offset”: Refers to the deviation of the green signal start time between adjacent intersections. Expressed as a percentage or second of the time of one cycle.

“Queue”: A queue of vehicles that are stopped in front of an intersection to wait for a signal.
“Intersection traffic jam”: A situation where the queue formed in front of the intersection cannot make money in a single green light. Therefore, when the signal queue is opened in one green traffic light time, there is no “traffic jam” at the intersection.

“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. The transmission wave when the signal waiting vehicle starts is called a starting 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.

“Road section”: A section from an arbitrary point on the road to another arbitrary point. In this embodiment, the following route, system | strain area, and a link are assumed as an example of a road area.
“Route”: A road section including a plurality of system sections. A boundary link where no system control is performed is included between adjacent system sections.
“System section”: A road section that performs system control described later. The system section includes approximately 3 to 5 links.

  “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.

“Sub-area” means an area divided so as to include one or a plurality of intersections where traffic signals that are signal-controlled with a common cycle length are installed.
"System control": By adjusting the traffic signal offset between the intersections included in a series of system sections set in the sub-area, it is easier to pass a specific direction of the system section with a green light (priority offset), and vice versa The control that makes it easy to stop with a red light.

“Link travel time”: The travel time of a link.
“Section travel time”: Refers to the travel time of the system section.
“Route travel time”: The travel time of a route.
“Actual travel time”: Travel time consisting of a difference in transit time between arbitrary points calculated based on the position and time included in the probe information of one probe vehicle. In the present embodiment, “actually measured link travel time” related to a link and “actually measured route travel time” related to a system section may be used as the actually measured travel time.

“Actual speed”: A traveling speed that is estimated to be measured by most vehicles when the vehicle actually travels on a certain road section.
Therefore, the actual speed of a certain road section does not include a signal waiting element at an intersection, and is a speed that mainly depends on the road structure such as road width and slope, and is approximately +10 km / h with respect to the regulation speed of the road section. It is said that the speed is about. As will be described later, in the present embodiment, this actual speed is estimated from probe information obtained from a plurality of probe vehicles.

[Traffic information processing system]
FIG. 1 is a schematic diagram showing an overall configuration of a traffic information processing system 20 according to an embodiment of the present invention.
In the traffic information processing system 20 of the present embodiment, the center apparatus 5 collects probe information including at least the vehicle position and the passing time data of the position from the probe vehicle 1 and performs data processing on the collected probe information. A service is provided that provides traffic information such as travel time on road sections, traffic conditions, and optimal routes.

As shown in FIG. 1, the traffic information processing system 20 includes an in-vehicle device 2 mounted on the probe vehicle 1, a base station 4, and a center device 5.
Wireless communication is possible between the in-vehicle device 2 and the base station 4, and wired communication is possible between the base station 4 and the center device 5 via a predetermined communication line 6. However, the communication between the base station 4 and the center device 5 may also be wireless communication.

The in-vehicle device 2 includes a vehicle speed sensor, a direction sensor, a GPS receiver, a memory, a timer, and the like. The in-vehicle device 2 collects the probe information of the probe vehicle 1 at every predetermined time or every fixed traveling distance and stores it in the memory.
The in-vehicle device 2 is connected to a communication device 3 such as a mobile phone or a smartphone, and the probe information stored in the memory can be transmitted to the outside via the communication device 3. The probe information transmitted from the probe vehicle 1 is sent to the center device 5 via the base station 4.

  The timing at which the probe vehicle 1 transmits the probe information is arbitrary, but in this embodiment, the probe information accumulated in the in-vehicle device 2 when the passenger requests the center device 5 to transmit the traffic information providing service. Send. In other words, when the passenger desires to be provided with a traffic jam situation, he / she operates the communication device 3 to transmit a service request signal to the center device 5. At this time, the communication device 3 transmits the probe information stored in the memory at the time of transmission of the request signal to the center device 5 together with the request signal.

[Configuration of center device]
FIG. 2 is a functional block diagram schematically showing the configuration of the center device 5.
As shown in FIG. 2, the center device 5 includes a transmission / reception unit 10, a data processing unit 11, a storage unit 12, and databases 13 and 14.
The transmission / reception unit 10 transmits / receives various data such as probe information and traffic congestion between the base station 4 and the data processing unit 11.

The data processing unit 11 is composed of a programmable computer device. The storage unit 12 includes a storage medium such as a hard disk or a semiconductor memory, and stores a computer program 15 for causing the data processing unit 11 to function as a “travel time calculation device”.
The database 13 stores probe information received from the probe vehicle 1. The database 14 stores map data. The map data includes data such as the positions of links and nodes belonging to the jurisdiction area of the center device 5 and their identification numbers.

The center device 5 of the present embodiment also has a traffic control function for controlling a plurality of traffic signal controllers, and the transmission / reception unit 10 can be used as a vehicle detector or a traffic signal controller (not shown) in the jurisdiction area. The communication line 6 is communicably connected.
The data processing unit 11 of the center device 5 performs system control and other traffic sensitivity control based on the vehicle sensor detection signal received by the transmission / reception unit 10, and the signal control parameters of each intersection generated as a result of this control are The data is recorded in the database 14 and transmitted to the traffic signal controller through the transceiver 10.

When the data processing unit 11 performs travel time calculation processing, which will be described later, the probe information, the length of the road section (link length, etc.) and the signal control parameters required for the calculation processing are read from the databases 13 and 14 respectively. The read data is temporarily stored in the memory of the storage unit 12.
Accordingly, the storage unit 12 of the center device 5 functions as an acquisition unit for acquiring the probe information, the section length, and the signal control parameter from the databases 13 and 14.

[Road section for travel time]
FIG. 3 is an explanatory diagram illustrating an example of a road section in which the data processing unit 11 calculates travel time.
As shown in FIG. 3, the road section for which the data processing unit 11 calculates travel time includes a link Li (i = 1, 2,...), A system section Sj (j = 1, 2,...), And a route RT. Is included.
Each system section Sj includes a plurality of (four in the illustrated example) links Li, and the adjacent system sections S1 to S3 are connected by boundary links L5 and L9.

The route RT is composed of an aggregate including a plurality of system sections S1, S2,... And boundary links L5 and L9 connecting them.
In the example of FIG. 3, attention is paid to the inflow link Li that flows into the arbitrary node n from the left side, but the inflow link that flows into the arbitrary node n from the right side may be used. Further, the shape of the system section Si shown in FIG. 3 is temporary, and the shape of the system section Si and the number of internal nodes can be changed by subarea division or combination performed according to the time zone.

Here, it is as follows when the definition of the parameter regarding a road section used by the data processing part 11 of this embodiment for the calculation process of travel time is enumerated.
TL: Link travel time when link Li is quiet JL: Link travel time when link Li is congested DL: Distance distance of link Li (link length)
C: Link Li cycle length R: Link Li red time

TS: Travel time when the grid section Sj is quiet JS: Travel time when the system section Sj is congested DS: Path distance (section length) of the system section Sj
VSm: Actual speed estimated from a plurality of probe information in the system section Sj TR: Travel time when the route RT is quiet JR: Travel time when the route RT is congested

[Calculation processing of travel time during quiet periods]
(Estimated actual speed)
The data processing unit 11 of the center device 5 estimates the actual speed VSm of the system section Sj as basic data for calculating the travel time when the road sections Li, Sj, RT are quiet. In the following, the travel time calculation process for the system section S1 and the link L1 in which the subscripts i and j are both “1” will be described, but the other system sections S2, S3,. , L3,... Are calculated in the same manner.

The data processing unit 11 reads a plurality of probe information whose vehicle positions are passing through the system section S1, from the database 13, and obtains a plurality of vehicle speed statistical values (for example, 90th percentile values) specified from the probe information. The actual speed VSm in the system section S1 is estimated.
The data processing unit 11 estimates the actual speed VSm of the system section S1 for each day of the week and date / time when the probe information is obtained.

(Link travel time during off-season)
The main factor that delays the travel time in running in a quiet vehicle is waiting for a signal at an intersection. Therefore, in the case of a quiet road section, it is reasonable to consider the travel time TL of the link L1 included in the road section separately into two terms on the right side of the following equation.
Link travel time TL = "link travel time" + "average signal waiting time"
Therefore, in the present embodiment, the data processing unit 11 calculates the link travel time TL during a quiet time for the link L1 using the above formula.

In the above formula, the “link travel time” in the first term on the right side is the travel time when the vehicle travels without waiting for a signal on the entire route of the link L1, and this travel time is calculated by “DL / VSm”. can do.
In addition, “average signal waiting time” (= “Tw”) in the second term on the right side is an average time when the link L1 stops signal waiting at the node at the downstream intersection, and this waiting time Tw is “ R ² / 2C ”. Hereinafter, the reason will be described with reference to FIG.

FIG. 4 is a graph showing the queue in front of the intersection and the traveling locus of the vehicle.
In FIG. 4, the horizontal axis represents time (seconds), the vertical axis represents the distance (m) from the stop line of the intersection, and “G”, “R”, and “Y” are the blue time, red time, and Represents the yellow hour.
In FIG. 4, a substantially triangular area with vertical hatching is a queue formed by red signals in one cycle. The sloping side SL on the left side of this area is the stop position of the vehicle that has entered the queue, and the vehicle first stops at the end of the queue in 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. Their stop and start positions each have a propagation velocity that extends upstream with time. This propagation velocity (inclinations of the inclined sides SL and SR) is the stop wave and the starting wave.
The data processing unit 11 of the center device 5 also records the stop wave and start wave speeds at each intersection in the database 13.

Here, since the area of the triangular area surrounded by the stop wave and the start wave represents the number of vehicles that stop at a red signal of one cycle, the number of vehicles per unit time that uniformly arrive at the intersection is represented by N (units / units). Second), the average waiting time Tw at the intersection is a value obtained by dividing the area of the triangular region by C × N.
That is, the average waiting time Tw can be calculated by the following equation.
Tw = (1/2) × R × R × N / (C × N)
= R ² / 2C

Therefore, the data processing unit 11 calculates the link travel time TL by the following equation.
TL = "link travel time" + "average signal waiting time"
= DL / VSm + R ² / 2C
The data processing unit 11 uses the above equation to calculate the link travel time when the link travel time TL of the single link L1 included in the system section S1 or the single links L5 and L10 not included in the system section S1 is necessary. TL is calculated, and the calculated travel time TL is stored in the database 14.

(Section travel time during off hours)
On the other hand, in the case of the system section S1, since a vehicle group is formed by system control, it is not possible to assume that the arrival of the vehicles at the intersection at the time of quiet is uniform.
That is, in the system section S1, a priority offset through which the through band passes in all sections is executed, or an offset that is easy to stop at a specific intersection is executed, so that a vehicle passing through the system section S1 receives a signal at each intersection. It does not always stop waiting.

Therefore, with respect to the links L1 to L4 included in the system section S1, the link travel time TL is calculated by the above-described calculation process for a single link, and the individual link travel times TL are simply summed up. It cannot be said that it reflects the actual travel time of S1.
Therefore, the data processing unit 11 assumes that the vehicle travels in the system section S1 at the actual speed VSm, and calculates the time required for a vehicle that departs from the start point of the system section S1 at a different time to arrive at the end point of the system section S1. The section travel time TS when the system section S1 is quiet is calculated from a plurality of required times obtained by simulation.

FIG. 5 is an explanatory diagram showing a method for simulating the section travel time TS of the system section S1.
In FIG. 5, the horizontal axis represents the distance (m) of the system section S1, and the vertical axis represents time (seconds). A1 to A4 indicate intersections included in the system section S1, and P1 and P2 indicate the start point and end point of the system section S1.
First, the data processing unit 11 generates an offset diagram (FIG. 5) for the system section S1 based on the signal control parameters of the intersections A1 to A4 read from the database 14.

Next, the data processing unit 11 generates a virtual passage time tk (k = 1, 2,..., N) for the starting point P1 by assigning the time length of one cycle C at predetermined intervals.
Then, the data processing unit 11 determines whether or not the virtual vehicle that has departed from the start point P1 at the passage time tk encounters the red time of the intersections A1 to A4 when traveling in the system section S1 at the actual speed VSm. If not encountered, the intersection is made to pass downstream, and if encountered, the intersection is re-started at the actual speed VSm at the blue start time, and the arrival time at the end point P2 is obtained.

In the example of FIG. 5, when a virtual vehicle that departs from the start point P1 at each passing time tk (k = 1, 2,... N) travels in the system section S1 at the actual speed VSm, two types of arrival times tx. , Ty arrive at the end point P2.
Therefore, in the case of a virtual vehicle that departs at time tk and arrives at time tk, the data processing unit 11 sets (tx−tk) as the time required to pass through the system section S1, departs at time tk, and time In the case of a virtual vehicle that has arrived at ty, (ty-tk) is set as the required time.

Then, the data processing unit 11 sets a time value obtained by performing predetermined statistical processing on the plurality of required times obtained by the above simulation as the section travel time TS of the system section S1.
For example, when adopting an average value, the data processing unit 11 sets an average value obtained by dividing a total value of n required times by n as a section travel time TS, and when adopting an intermediate value, n required values The half of the maximum value and the minimum value of the time is set as the section travel time TS.

It should be noted that a vehicle stopped at a red signal at the intersections A1 to A4 cannot suddenly travel at the actual speed VSm when it next becomes a green signal. For example, as indicated by a broken line in FIG. It is considered that the actual speed VSm is reached.
Therefore, when the required time required for traveling in the system section S1 is simulated, if the arrival times tx and ty are determined in consideration of the acceleration time, the required time can be accurately calculated.

(Route travel time during off season)
In the route RT shown in FIG. 3, system control is not performed on the boundary links L5 and L10 between the system sections Sj. For this reason, the vehicle passing through the route RT is more likely to stop waiting for a signal at the boundary links L5 and L10 than when passing through the system section S1 to S3.
Therefore, the data processing unit 11 sums up the section travel time TS of the system section Sj included in the route RT and the delay when passing through the boundary links L5 and L10 connecting them (link travel time TL of the links L5 and L10). This time is defined as a route travel time TR at a quiet time.

In other words, the data processing unit 11 calculates a route travel time TR during a quiet time for the route RT using the following equation.
TR = ΣTS + ΣTLp
However, in the above formula, “TLp” is the link travel time TL when one or more boundary links Lp (p = 5, 10,...) Included in the route RT is quiet.

[Calculation of travel time during traffic jams]
As described above, the travel times TL and TS that depend on the actual speed VSm are based on the assumption that the system section S1 is quiet. If “stay time” is added, travel times TL and TS at the time of traffic congestion can be obtained.
That is, the following formulas (1) and (2) are established between the travel times JL and JS when there is a traffic jam and the travel times TL and TS when the traffic is quiet.

JL = TL + "Time spent in traffic" at the link ...... (1)
JS = TS + “Dwelling time in traffic jam” in the relevant section (……)
Here, the “staying time in the jam” refers to a delay time caused by the traffic jam, excluding the stop time at the traffic light and the cruise time at the actual speed. Since this “stay time in traffic jam” is small and easily converges, if the probe information of at least one probe vehicle 1 can be obtained after predetermined cleansing, the stay time in traffic jam is obtained. Can be collected accurately.

(Link travel time in traffic)
If the “stay time in traffic jam” (= “JWL”) of the link L1 in the above formula (1) can be calculated, the link travel time JL at the time of traffic jam on the link L1 can be obtained by the formula (1). The stay time JWL in the traffic jam can be calculated by the following equation (3), for example.
JWL = "actual link travel time"-"maximum link travel time in quiet" ...... (3)

Here, “actually measured link travel time” in the expression (3) is a passage time from the start point to the end point of the link L1 obtained from the probe information of the probe vehicle 1.
The reason why the above equation (3) is satisfied is that when the actual link travel time of the probe vehicle 1 is obtained, if the actual link travel time is larger than the maximum link travel time in a quiet time, traffic congestion occurs in the link L1. It is because it can be estimated that this has occurred.

When obtaining the actual link travel time, the data processing unit 11 calculates the actual link travel time from probe information that has undergone a predetermined cleansing process for removing abnormal values.
In such cleansing processing, for example, probe information of the probe vehicle 1 that can be regarded as having stopped at the same position for a predetermined time or longer is not adopted, probe information in which speed data with zero speed continues is not adopted, or probe vehicle 1 Includes a process of not adopting probe information which is data obtained by reversing 360 degrees (U-turn) at a predetermined position.

The “maximum link travel time during quiet periods” in equation (3) can be defined as a value obtained by adding the red time R of the intersection to the quotient obtained by dividing the link length DL by the actual speed VSm. That is, the maximum link travel time when the link L1 is quiet can be calculated by the following equation.
Maximum link travel time in quiet time = (DL / VSm) + R
Therefore, the above-described equation (3) is as follows.
JWL = “actual link travel time” − {(DL / VSm) + R}

When providing the travel time of the link L1, the data processing unit 11 first determines whether the link L1 is quiet at the time of provision.
This determination can be made based on, for example, the degree of congestion of the link L1 estimated from the detection signal of the vehicle sensor, or VICS (“VICS” is a registered trademark) information. Further, the above determination may be made based on the sign of the right side of the equation (3). In this case, when the right side of Expression (3) is a positive number, it is determined that traffic congestion has occurred in the link L1, and when it is equal to or less than zero, it may be determined that traffic congestion has not occurred in the link L1.

  When it is determined that the link L1 is quiet, the data processing unit 11 adopts the link travel time TL during the quiet time as the travel time of the link L1. The link travel time JL at the time of traffic jam is adopted as the travel time of the link L1.

(Section travel time during traffic jams)
If the “stay time in traffic jam” (= “JWS”) of the system section S1 in the expression (2) can be calculated, the section travel time JS at the time of traffic congestion of the system section S1 can be obtained by the expression (2). The stay time JWS in the traffic jam can be calculated by the following equation (4), for example.
JWS = "actual section travel time"-"maximum section travel time in quiet" ...... (4)

Here, “actually measured section travel time” in the equation (4) is a passage time from the start point to the end point of the system section S1 obtained from the probe information of the probe vehicle 1.
The reason why the above equation (4) holds is that, when the actual travel time of the probe vehicle 1 is obtained, if the actual travel time of the probe vehicle 1 is larger than the maximum travel time of the quiet time, the system section S1 This is because it can be estimated that traffic congestion has occurred in some of the included links L1 to L4.

The data processing unit 11 also calculates the actually measured section travel time from the probe information that has undergone the above-described cleansing process for removing abnormal values, even when the actual section travel time is obtained.
The “maximum travel time during quiet periods” in the equation (4) can be obtained by selecting the longest required time from the plurality of required times of the system section S1 obtained in the above simulation.

When providing the travel time of the system section S1, the data processing unit 11 first determines whether or not the system section S1 is quiet at the time of provision.
This determination can also be made based on the congestion degree of the system section S1 estimated from the sensing signal of the vehicle detector and the VICS information, or based on the sign of the right side of the equation (4). You can also. When the right side of Expression (4) is a positive number, it is determined that traffic congestion has occurred in the system section S1, and when it is less than or equal to zero, it may be determined that traffic congestion has not occurred in the system section S1.

  When it is determined that the grid section S1 is quiet, the data processing unit 11 adopts the section travel time TS during the quiet time as the travel time of the grid section S1, and when it is determined that the grid section S1 is not quiet, the formula (4) The calculated section travel time JS at the time of traffic jam is adopted as the travel time of the system section S1.

(Route travel time in traffic)
In the route RT shown in FIG. 3, when the system section S1 is quiet and the system section S2 is not quiet, the data processing unit 11 adopts the section travel time TS when the system section S1 is quiet, and the system section S2 For the traffic, the section travel time JS at the time of traffic jam is adopted.
In addition, the data processing unit 11 can adopt the link travel times TL and JL for the boundary links L5 and L10 depending on whether the link is not quiet or not when the link is quiet.

Therefore, the data processing unit 11 calculates the route travel time JR at the time of traffic congestion on the route RT using the following equation.
JR = Σ (TS or JS) + Σ (TLp or JLp)
However, in the above formula, “TLp” is the link travel time TL when one or more boundary links Lp (p = 5, 10,...) Included in the route RT is quiet, and “JLp” This is the link travel time JL at the time of congestion of one or more boundary links Lp included in the route RT.

  As shown in the above equation, the data processing unit 11 adopts the travel times TS and TL during the quiet time among the system sections Sj and the links Li included in the route RT, and determines the traffic congestion. The travel time JS, JL at the time of traffic jam is adopted for the above-mentioned, and the route travel time LR at the time of traffic jam on the route RT is calculated by adding all the adopted travel times.

[Effect of center device]
As described above, according to the center device (travel time calculation device) 5 of the present embodiment, the actual speed VSm of the road section (system section Sj in the present embodiment) is estimated based on the probe information acquired from the database 13, From the estimated actual speed actual speed VSm, the section lengths DL and DS acquired from the database 14, and the signal control parameters, travel times TL and TS of the road section are calculated.

  Accordingly, the travel time TL, TS can be accurately calculated even when the number of probe information data is small, compared to the conventional calculation device in which the average value of the actually measured travel time obtained for each probe information is the travel time, and the travel time TL , TS calculation accuracy can be improved.

[First Modification]
In the above-described embodiment, the data processing unit 11 specifies the travel time as one value and uses the specified travel time as traffic information that is provided to the outside. However, the travel time providing method is fixed to one value. Instead of this, for example, a providing method having a time width may be adopted by transmitting the maximum value and the minimum value of travel time in a predetermined road section.

For example, when the above providing method is adopted, the maximum value and the minimum value of the link travel time TL during a quiet time are as follows.
TLmax: Link travel time (DL / Vsm) + Red time (R)
TLmin: Link travel time (DL / Vsm)

In addition, the maximum value and the minimum value of the section travel time TS in a quiet time are as follows.
TSmax: Maximum value among a plurality of required times obtained as a result of simulation TSmin: Minimum value among a plurality of required times obtained as a result of simulation Further, maximum value and minimum of route travel time TR in a quiet time The values are as follows:
TRmax: ΣTSmax + ΣTLmax
TRmin: ΣTSmin + ΣTLmin

The embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of rights of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope equivalent to the configurations described in the claims.
For example, in the above-described embodiment, the center device 5 has a traffic control function for controlling a plurality of traffic signal controllers. However, the traffic control function is different from the center device 5 (hereinafter referred to as “another device”). It may be a system configuration that is assigned to the “device”.

In the case of such a system configuration, another device having a traffic control function transmits a signal control parameter to the center device 5 through a communication line, so that the center device 5 can acquire the signal control parameter.
Further, in the case of a system in which another device provides a signal control parameter to the vehicle by wireless communication for the purpose of safe driving support, the center device 5 transmits the received signal control parameter to the center device 5 so that the center device 5 You may make it acquire a signal control parameter.

DESCRIPTION OF SYMBOLS 1 Probe vehicle 2 Onboard equipment 3 Communication apparatus 4 Base station 5 Center apparatus (travel time calculation apparatus)
10 Transmission / Reception Unit 11 Data Processing Unit 12 Storage Unit (Acquisition Unit)
13 Database 14 Database

Claims (12)

An apparatus for calculating travel time when a vehicle passes through a road section,
An acquisition unit for acquiring probe information of one or a plurality of probe vehicles passing through the road section, a section length of the road section, and a signal control parameter of an intersection of the road section;
A data processing unit that estimates the actual speed of the road section based on the acquired probe information, and calculates the travel time of the road section from the estimated actual speed and the acquired section length and signal control parameters;
A travel time calculation device comprising: The road section includes a link flowing into a predetermined intersection,
The data processing unit calculates a link travel time required for travel of the link from the estimated actual speed and the acquired link length,
From the intersection red time and cycle length included in the acquired signal control parameters, calculate the average signal waiting time at the intersection,
The travel time calculation device according to claim 1, wherein the link travel time of the link is calculated from the calculated link travel time and the average signal waiting time. 3. The trip according to claim 2, wherein the data processing unit calculates the average signal waiting time Tw using the following equation, where Tw is the average signal waiting time at the intersection, R is the red time, and C is the cycle length. Time calculation device.
Tw = R ² / 2C The road section includes a system section having a plurality of links in a sub-area under system control,
The data processing unit simulates the time required for the vehicle that has departed from the start point of the system section at a different time to arrive at the end point of the system section, assuming that the vehicle travels at the estimated actual speed. The travel time calculation device according to any one of claims 1 to 3, wherein a section travel time of the system section is calculated based on a plurality of required times obtained as a result. The road section includes a route having a plurality of system sections having a plurality of links in a sub-area under system control, and a boundary link connecting them,
The said data processing part calculates the route travel time of the said route by the sum of the link travel time of the said boundary link, and the section travel time of the said some system section. Travel time calculation device.   The said data processing part is the travel time at the time of traffic congestion of the said road section further adding the stay time in traffic congestion to the travel time calculated in Claims 2-5, when the said road section is not quiet. The travel time calculation apparatus according to any one of 2 to 5. When the road section is the link, the data processing unit calculates the maximum link travel time in a quiet time by adding the red time of the intersection to the quotient obtained by dividing the acquired link length by the estimated actual speed. And
The travel time calculation device according to claim 6, wherein the stay time in the traffic jam of the link is calculated by subtracting the maximum link travel time at a quiet time from the actually measured link travel time of the probe vehicle.   The travel time according to claim 7, wherein the data processing unit determines whether or not the link is not quiet depending on whether or not the actually measured link travel time of the probe vehicle is larger than a maximum link travel time during a quiet time. Calculation device. The data processing unit, when the road section is the system section, the maximum time of a plurality of the required time obtained as a result of simulation is a maximum section travel time in a quiet time,
The travel time calculation device according to claim 6, wherein the stay time in the traffic congestion of the system section is calculated by subtracting the maximum section travel time during quiet periods from the actually measured section travel time of the probe vehicle.   The travel according to claim 9, wherein the data processing unit determines whether or not the system section is not quiet depending on whether or not the actually measured section travel time of the probe vehicle is larger than a maximum section travel time at a quiet time. Time calculation device. A method for calculating travel time when a vehicle passes through a road section,
Obtaining probe information of one or more probe vehicles passing through the road section, a section length of the road section, and a signal control parameter of an intersection of the road section;
Estimating the actual speed of the road segment based on the acquired probe information,
A travel time calculation method for calculating the travel time of the road section from the estimated actual speed, the acquired section length, and the signal control parameter. A computer program for causing a computer to execute processing for calculating travel time when a vehicle passes through a road section,
Obtaining probe information of one or more probe vehicles passing through the road section, a section length of the road section, and a signal control parameter of an intersection of the road section;
Estimating an actual speed of the road segment based on the acquired probe information;
Calculating the travel time of the road section from the estimated actual speed and the acquired section length and signal control parameters;
A computer program comprising:

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