JP4753084B2 - Traffic calculation system at intersections - Google Patents

Description

  The present invention estimates the traffic volume at an intersection as an elemental technology necessary for realizing signal control and information provision on a ground system that is safe, smooth, or environmentally friendly, safe driving in an on-vehicle system, and environmental measures. , Related to prediction technology.

Known techniques for measuring traffic with a measuring device installed on the ground include optical beacons, ultrasonic vehicle detectors, loop vehicle detectors, image detectors, far-infrared sensors, and the like. Especially on ordinary roads, ultrasonic sensors are widely used. For highways, installation standards are determined based on the distance from the intersection.
However, from the viewpoint of information provision and advanced signal control, this installation standard is not sufficient, and it cannot be said that traffic volume can be grasped sufficiently. In addition, since the sensor is not installed on the narrow street, it is impossible to grasp a vehicle flowing into the main line from the narrow street or a vehicle flowing out from the main line into the narrow street.

From the above, at present, the measurement accuracy or estimation accuracy of the traffic volume arriving at the intersection is not sufficient.
In addition, as a method that does not use ground measurement equipment, probe data (also referred to as uplink data) collected from a specific vehicle (referred to as a probe vehicle) is transmitted to a traffic control center through an optical beacon, a mobile phone, etc. Techniques for estimating link travel time with higher accuracy at the center have been studied, experimented, and partly put into practical use.

However, a technique for estimating the traffic volume at an intersection using probe data has not been considered so far.
The present invention can be used for daily traffic management by accurately estimating the traffic volume arriving at an intersection, or used for prediction of stop queue length in real time. An object of the present invention is to provide a traffic volume calculation system at an intersection that can realize the provision of information.

  A traffic volume calculation system according to the present invention includes probe data acquisition means for acquiring probe data including vehicle position data measured by an in-vehicle device mounted on a vehicle entering an intersection, and signal switching of a traffic light installed at the intersection. Based on the signal switching timing acquisition means for acquiring timing information, the vehicle position data of the vehicle acquired from the probe data acquisition means, and the signal switching timing information acquired from the signal switching timing acquisition means, An arrival traffic volume calculating means for calculating the arrival traffic volume;

In this system, the arrival traffic volume at the intersection can be calculated based on the vehicle position data measured by the in-vehicle device and the signal switching timing information, which is very advantageous in terms of cost.
It is desirable that this traffic volume calculation system further includes a traffic jam judging means for judging traffic jams and non-car jams at the intersection. When the intersection is not congested by the determination of the traffic congestion determination means, the arrival traffic volume calculation means, the red light start time, the position where the vehicle stopped at the end of the red light waiting example and the stop time, By processing the probe data collected on the vehicle in synchronization, the arrival traffic at the intersection can be easily calculated.

  In addition, when the intersection is not congested, the arrival traffic volume calculation means calculates a red signal start time, a green signal start time, a time when the vehicle stops at the end of the red signal waiting example, and the vehicle The arrival traffic volume at the intersection can also be easily calculated using the time at which the vehicle passed through the intersection. “Passing an intersection” means passing a predetermined position (such as a stop line) near the intersection (the same applies hereinafter).

  The traffic volume calculation system according to the present invention includes a probe data acquisition unit that enters the intersection and acquires probe data including vehicle position data measured by an in-vehicle device mounted on the vehicle, and the probe data acquisition unit. Arrival traffic volume calculation that calculates the arrival traffic volume at the intersection based on data such as the vehicle position and the stop time at the end of the red signal waiting example when at least two vehicles stopped at the same red signal obtained And a system having the means. In this system, even if the intersection is congested or not congested, if there is at least two probe data in the same stop queue length, this data and signal switching timing By processing the information data in synchronization, the traffic volume arriving at the intersection can be easily calculated. “Stop at the same red signal” means that two units stop during the same red signal and after the start of the red signal until the starting wave propagates (the same applies hereinafter). .

Further, if the correlation between the traffic volume measured by the vehicle detector upstream of the intersection and the arrival traffic volume calculated by the arrival traffic volume calculation means is obtained, the correlation and the traffic measured by the vehicle sensor are determined. The arrival traffic volume can be predicted from the volume.
Moreover, the arrival traffic volume of the time slot | zone when the said probe data was not acquired can be estimated from the said correlation and the traffic volume measured with the vehicle sensor in the time slot | zone when the probe data was not acquired.

  The system for determining the arrival traffic volume using the correlation is particularly effective when there is a branch road where a vehicle flows in and out from another road between the intersection and the vehicle detector.

The arrival traffic data calculated using the present invention can be used for daily traffic management such as capacity monitoring of roads and intersections, daily reports, and long-term prediction of traffic volume. It can also be used as one of basic information such as signal control and VICS.
Predictive signal control that determines the necessity of extending the green time of traffic lights by using the predicted information on the arrival traffic volume at intersections, thereby delaying the start of traffic jams and suppressing the occurrence of traffic jams It can be performed. In addition, adaptive signal control can be performed in which a split is determined in proportion to traffic demand at an intersection.

  In addition, in the roadside device or traffic control center, short-term traffic flow behavior prediction information is created using traffic data such as arrival traffic volume prediction information calculated by the present invention, and the vehicle is located upstream of the intersection. When the vehicle arrives, it provides prediction information of the traffic flow behavior until the vehicle passes through the intersection by road-to-vehicle communication, so that the vehicle travels to the intersection (dilemma driving control etc.) and environment (idling) It is possible to provide information and automatic travel control that take into account stop control and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, terms are defined.
“Traffic volume”: Number of vehicles passing per unit time.
“Occupied time”: The total time that the vehicle exists in the detection area of the vehicle detector per unit time.
“Occupancy rate”: Occupation time / (unit time)
“Probe vehicle”: A vehicle equipped with a specific in-vehicle device 2 capable of transmitting data such as vehicle position, speed, and time necessary for carrying out the present invention.

“Probe data”: data such as vehicle position, speed, and time obtained from the in-vehicle device 2 of the probe vehicle. The probe data is data such as vehicle position, speed, time, etc. every predetermined time, every predetermined distance traveling, every predetermined acceleration / deceleration, or every predetermined azimuth change. , Including data such as speed and time.
“Stop queue”: A queue of vehicles waiting for a signal.

“Signal switching timing information”: Information relating to the switching time of red, blue, and yellow at the intersection.
“Signal period”: The period from the start of red (blue) of a signal to the start of the next red (blue).
“Arrival traffic”: Traffic that is added to the end of the stop queue when waiting for traffic lights at the intersection, so-called traffic demand at the intersection.
“Intersection is congested” means a situation where a stop queue cannot be made with a single green light. “Intersection is not congested” refers to a situation where a stop queue can be made with a single green light.
―How to find arrival traffic―
FIG. 1 is a map showing an intersection that is a target of arrival traffic calculation and a road R (also referred to as a target road) R that flows into the intersection.

An upstream roadside device 5 that performs road-to-vehicle communication with a vehicle such as a probe vehicle is installed at a roadside position upstream of the road R flowing into the intersection. A downstream roadside device 5 is also installed at the exit of the intersection. These roadside devices 5 use narrow area wireless communication such as optical beacons and DSRC, but may use medium area wireless communication such as wireless LAN.
The location of the roadside device 5 is preferably on the road R side when using narrow-area wireless communication. However, when using wide-area wireless communication such as mid-range wireless communication or a mobile phone, road-to-vehicle communication is performed with the vehicle. You can install it anywhere you can.

In addition, a signal control device 4 for controlling the lighting timing of the red, yellow, and blue signals of the traffic light is installed at the intersection.
The roadside device 5 is connected to the traffic control center 3 and the probe center 3a via a communication line as will be described later with reference to FIG.
The roadside device 5 receives the probe data of the probe vehicle that enters the intersection through the target road R.

Regarding the handling of probe data, as shown later in the embodiments of FIGS. 12 and 13, a wide area radio such as a mobile phone mounted on or brought into the probe vehicle from the probe vehicle without passing through the roadside device 5. It is also conceivable to perform transmission directly to the probe center 3a using communication (described later).
FIG. 2 is a graph showing the running behavior of the vehicle at the intersection, where the horizontal axis represents time and the vertical axis represents the distance from the stop line of the intersection.

  Since the travel locus of the probe vehicle can be known from the vehicle identification number and probe data obtained from the probe vehicle, the distance and speed from the stop line of the intersection for each time of the probe vehicle can be grasped as shown in FIG. A traveling locus U of a simple probe vehicle is obtained. Also, based on the signal switching timing information obtained from the signal control device 4, the start time of the red signal (which may include a yellow signal; the same applies hereinafter) and the start time of the blue signal are also obtained. Fill in the graph.

  A triangular portion represented by a vertical line in FIG. 2 represents a stop queue of the vehicle. The upper side of the triangle represents the stop position of the vehicle that has entered the stop queue. In the example of FIG. 2, the vehicle stops at the end of the red light stop queue. The diagonally lower side of the triangle 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 stop queue. Since the stop position and the start position each extend upstream with time, each has a propagation velocity. These are called “stop wave” and “start wave”.

The point at which the stop wave and the start wave cross represents a boundary point where the stop queue gradually decreases while the stopped vehicle travels in the stop queue. Vehicles that enter the intersection after this time travel in the procession of moving vehicles.
In this way, depending on the degree of traffic congestion, traffic volume, and signal switching timing information, the traveling vehicle may stop at the end of the stop queue waiting for traffic lights, or may add to the end of a moving queue with a green light. Or, if the vehicle passes smoothly through the intersection without adding to the stop queue length, various traveling tracks can be obtained.

Hereinafter, the method of calculating the arrival traffic will be described separately for cases (1) and (2).
(1) When the intersection is not congested FIG. 3 is a graph showing the running behavior of the vehicle at the intersection. The horizontal axis represents time, and the vertical axis represents the distance to the intersection. Let red signal start time be time tr and green signal start time be tg.
Probe data of a probe vehicle that enters the intersection through the target road R is received by the roadside device 5 and accumulated in the roadside device 5. This information is also accumulated in the traffic control center 3 through the roadside device 5. The probe data may be received by the roadside device 5 on the upstream side or the roadside device 5 on the downstream side of the intersection. Usually, due to the time delay of probe data transmission, it is often received by the roadside device 5 on the downstream side. In the case of mid-range wireless communication such as a wireless LAN, the roadside device 5 on the upstream side of the intersection may be able to receive even after passing through the intersection.

When this data is analyzed, the time when the probe vehicle passes through each point of the inflow road R and the speed at each time are obtained. It is assumed that the travel locus U is obtained as shown in FIG.
It is assumed that the time when the probe vehicle enters the stop queue and stops is ts, the time when the probe vehicle starts from the top of the stop queue is tm, and the time when the probe vehicle passes through the intersection stop line is tp. Let L be the distance to the intersection stop line when the probe vehicle is stopped. At time ts, the probe vehicle reaches the end of the stop queue at a distance L from the intersection stop line, stops, and then the signal turns blue at time tg and starts moving toward the intersection at time tm. It can be seen that the vehicle passed the stop line at the intersection at tp.

The number E of vehicles constituting the stop queue from the intersection stop line to the distance L is the distance between the heads of the stop queue (the distance between the heads of the preceding and following vehicles; see FIG. 4) Lh. If so,
E = L / Lh (1 set)
The relationship holds.

Further, assuming that the traffic volume qs that passes through the stop line at the intersection at a green light (referred to as the amount of profit) is a constant, the following equation is obtained.
E = qs (tp−tg) (Equation 2)
From (Expression 1) and (Expression 2), the following expression is obtained as a relational expression between Lh and qs.
Lh = L / {qs (tp-tg)} (Expression 3)
Since the stop queue is the traffic volume that arrived from upstream from time tr to time ts, the arrival traffic volume q at the intersection can be obtained by using signal waiting stop time ts and red signal start time tr. And the signal waiting stop position L are obtained by the following equation.

q = L / {Lh (ts−tr)} (Formula 4)
Further, the arrival traffic volume q at the intersection can be calculated by using (Equation 2) as the difference between the signal waiting time ts and the red signal start time tr and the difference between the intersection passage time tp and the green signal start time tg. Based on this, the following equation is obtained.
q = E / (ts-tr) = qs (tp-tg) / (ts-tr) (Formula 5)
Assuming that the unit of time is seconds, the traffic volume QC and the 5-minute traffic volume Q300 per one signal cycle (T seconds) that are often used are obtained by the following equations.

QC = qT (6 formulas)
Q300 = 300q (7 formulas)
Note that when ts and tr are close in time, the accuracy of the estimated traffic volume is lowered, and therefore (ts−tr) is sufficiently large (for example, when it is more than half of the signal period). Only may be used as data.

The Lh and qs may be constants for each intersection. However, the distance Lh between the stopped vehicle heads may change depending on the ratio of large vehicles in the stop queue so that there are intersections with large traffic volume and small traffic volumes. For this reason, it can also measure by the method demonstrated below, without making distance Lh between stop vehicle heads into a constant.
When the road-side device 5 installed on the ground can measure the occupied time T of the passing vehicle and the vehicle speed v, the stop head-to-head distance Lh can also be obtained by the following method.

The average vehicle length Lc is obtained as follows.
Lc = E [T · v] (8 formulas)
Here, E [*] indicates an average operation of * for a plurality of vehicles passing through the roadside device 5. The average operation period may be, for example, the period of the latest signal period or a plurality of signal periods.
The average inter-vehicle distance of stopped vehicles in the stop queue (distance between the tail of the front vehicle and the head of the rear vehicle; see FIG. 4) Ld may be considered as a constant. It is obtained by.

Lh = Lc + Ld (9 formulas)
In this way, the stop head distance Lh is obtained from the average vehicle length Lc and the average inter-vehicle distance Ld.
The blur amount qs can be obtained based on the above (Equation 3) using the distance Lh between the stopped vehicle heads. Further, when a vehicle detector is installed near the stop line at the intersection, the blur amount qs can be directly obtained from the measured value of the vehicle detector without using the distance Lh between the stopped vehicle heads.
(2) When the intersection is congested FIG. 5 is a graph showing the running behavior of the vehicle when the intersection is congested. Since the intersection is congested, the stop wave suddenly rises at the red light start time tr. This is due to the remaining redemption stop queue of the previous red light. From this time tr to the time ts1 when the probe vehicle reaches the tail of the stop queue, the traffic flow from the upstream side is not reflected, so (Expression 1) to (Expression 5) do not hold.

In this case, as shown in FIG. 5, it is assumed that another probe vehicle C2 enters the same stop queue.
It is assumed that the two probe vehicles C1 and C2 stop at the same red light. At time ts1, probe vehicle C1 stops at the end of the stop queue at a distance L1 from the intersection stop line, then the signal turns blue, starts moving towards the intersection, and passes the stop line at the intersection. Suppose that The locus of the probe vehicle C1 is U1.

At time ts2, the probe vehicle C2 reaches the end of the same stop queue as the probe vehicle C1 at a distance L2 from the intersection stop line, stops, and then the signal turns blue and starts moving toward the intersection. Suppose that you cannot pass through the intersection and stop at the next red light stop queue. The locus of the probe vehicle C2 is U2.
At this time, the stop queue defined by the distance (L2−L1) between the two probe vehicles is the traffic flowing in from the upstream from the time ts1 to the time ts2.

The traffic volume q at the intersection can be obtained by the following equation, where E ′ is the number of vehicles present during this time.
q = E ′ / (ts2−ts1)
= (L2-L1) / {Lh (ts2-ts1)} (Equation 10)
This (Equation 10) can be used even when the intersection is not congested if probe data can be obtained from two probe vehicles that enter the intersection and stop at the same red light.

  In the case described above, the arrival traffic volume q is obtained using the probe data of two probe vehicles. However, in order to improve the calculation accuracy of the arrival traffic volume q, three or more probe data are used ( A plurality of (10 formulas) may be acquired. If there are a plurality of equations, a plurality of solutions can be obtained. Therefore, the calculation accuracy can be improved by performing statistical processing such as averaging the solutions. Further, when a large amount of probe data is obtained, data indicating an abnormal value of the speed of the non-congested part may be removed, or only data near the median speed may be used.

The determination as to whether or not the intersection is congested, that is, the determination as to whether or not the vehicle is congested as there are vehicles that wait twice or more at the intersection can be performed as follows.
As shown in FIG. 6 (a), a distance Lj (for example, about 150 m upstream from the intersection) is set so that when the signal stop queue extends to this position, the red signal waits twice or more. A vehicle detector 6 for detecting traffic congestion is installed nearby. It is assumed that the installation position of the vehicle detector 6 is a distance Ls from the stop line at the intersection. Examples of the vehicle sensor 6 include an ultrasonic vehicle sensor, a loop vehicle sensor, an image sensor, and a far infrared sensor. If the occupation time or the occupation rate measured by the vehicle sensor 6 is higher than a predetermined threshold, it can be determined that the traffic jam has spread to this point.

If the occupation ratio is expressed as Oc, the time occupation ratio Oc is expressed as follows: Lc is the average vehicle length of passing vehicles that have passed during the measurement time (unit time) T, and v is the average speed.
Oc = (1 / T) Σ (Lc / v) (11 formulas)
It is represented by As can be seen from this (Equation 11), the occupation rate increases as the speed decreases. If the occupancy rate increases, it can be seen that the speed of the vehicle is decreasing, so that it can be estimated that the traffic jam extends to the vicinity of the vehicle detector 6.

Therefore, it is possible to determine the traffic jam according to the size of the occupation rate. For example, as shown in FIG. 6 (b), when the occupation rate is 0% or more and less than 30%, the degree of congestion is 1, and when the occupation rate is between 30% or more and less than 55%, the congestion level is 2, and the occupation rate is 55% or more. In this case, the traffic congestion degree may be determined by comparing the degree of the traffic congestion degree with a threshold value as the traffic congestion degree 3 according to the traffic conditions at the point.
In addition, it is possible to determine whether there is traffic jam or no traffic jam using probe data. FIG. 7 is a graph showing the running behavior of the vehicle at the intersection, and depicts the trajectory of the probe vehicle. If the probe vehicle is less than one signal period from the time when it stops in the stop queue waiting until it passes through the intersection, it is determined that it is waiting for one signal and it is determined that there is no traffic jam. If it takes more than one signal period, it is determined that the signal is waiting twice and it is determined that there is a traffic jam.

In the description so far, the arrival traffic volume is obtained using the trajectory of the probe vehicle. However, the probe vehicle does not always pass through the intersection.
In this case, ultrasonic detectors, loop detectors, image detectors, far-infrared detectors, etc. installed to measure the traffic volume, occupation time, vehicle speed, etc. of vehicles traveling on the road R flowing into the intersection The vehicle sensor 7 is used (see FIG. 8). The installation position of the vehicle detector 7 is not particularly limited as long as it is on the target road R side. The relationship with the installation position of the roadside apparatus 5 is also arbitrary. For example, the roadside device 5 and the vehicle detector 7 may be close to each other (when the roadside device 5 is an optical beacon, road-to-vehicle communication and traffic volume measurement are shared), which are installed apart from each other on a line. It may be tied.

  The correlation between the traffic volume measured by the vehicle detector 7 (referred to as point traffic volume) and the arrival traffic volume calculated using the trajectory of the probe vehicle is analyzed. Then, using the point-to-point traffic volume measured by the vehicle sensor 7 and this correlation, it is possible to estimate the arrival traffic volume during the time period when probe data could not be obtained. It is also possible to predict the arrival traffic volume in the near future.

Actually, in the road R flowing into the intersection, there may be a branch road between the intersection and the vehicle detector 7 where the vehicle flows in and out from the other road R as shown in FIG.
The method using this correlation is when the vehicle detector 7 cannot be installed near the intersection and there is a branch road where the vehicle flows in and out from another road R between the intersection and the vehicle detector 7. Is also effective. This is because there is a traffic volume flowing from the narrow street or a traffic volume flowing out to the narrow street, so that the point traffic volume measured by the vehicle detector 7 cannot be used as it is.

  Therefore, the correlation between the point traffic volume measured by the vehicle detector 7 and the arrival traffic volume is analyzed, and a correlation parameter is calculated. That is, Q is the arrival traffic volume at the intersection obtained by (4), (5) or (10), Qup is the point traffic measured by the vehicle detector 7, and the total time is s seconds. The free travel time from the installation point of the device 7 to the intersection is T seconds. Here, Q (t1, t2) represents the traffic volume from time t1 to time t2.

A correlation parameter between Qup (tTs, tT) and Q (ts, t) is obtained. For example, the correlation parameter a is calculated using the following equation.
Q = aQup (12)
Alternatively, correlation parameters a and b are calculated using the following equations.
Q = aQup + b (13)
Using these correlation parameters, the arrival traffic volume Q (t + Ts, t + T) at the intersection at time t + T is predicted from the point traffic volume Qup (ts, t) of the vehicle detector 7 obtained at time t. be able to. Further, in the time zone when the probe data is not obtained, using these correlation parameters, the traffic volume Qup (tTs, tT) of the vehicle detector 7 obtained at time t-T is used to determine the intersection of time t. The arrival traffic Q (ts, t) can be estimated.

As can be seen from the above analysis, from the calculated correlation parameter and the point traffic volume of the vehicle detector 7 obtained in real time, after the time when the vehicle reaches the intersection (T seconds later), the downstream intersection The amount of arrival traffic that flows in can be predicted. Therefore, the arrival traffic volume in the near future can be predicted based on the point traffic volume measured by the vehicle detector 7.
Since the correlation parameter does not change greatly in a short time, it may be averaged or smoothed in consideration of data calculated in the past.

In the above method, an example of formulating a linear (primary) correlation is shown, but a nonlinear formulation such as a relationship consisting of two straight lines or a quadratic equation may be used. In the above description, the correlation is calculated regardless of the time. However, the correlation may be calculated in units of time.
In the above, only the measurement value of one vehicle detector 7 is used as the upstream point traffic volume. However, the weighted cumulative traffic is calculated by installing the vehicle detectors 7 at a plurality of points and using these point traffic volumes. A quantity may be used, or a formulation such as multiple correlation may be used.

  In addition, from the correlation parameters obtained above and the point traffic measured by the vehicle detector 7, the time-dependent data of the arrival traffic at the intersection is statistically analyzed and stored in the memory for daily traffic management. It can also be useful. Here, the arrival traffic volume for each time of arrival traffic may be the arrival traffic volume calculated directly using (Equation 4), (Equation 5) or (Equation 10) as long as the data for that time zone exists. The arrival traffic volume obtained by using the point traffic volume of the vehicle detector 7 and the correlation parameter may be used.

The time unit for counting the arrival traffic may be any one cycle of the signal, every 5 minutes, every 15 minutes, every hour, every day, or the like. In addition, this data may be calculated for each day of the week, holidays, weekdays, presence or absence of five or ten days, presence or absence of trays or holidays, presence or absence of events, or weather.
FIG. 9 is a flowchart showing the entire procedure of the arrival traffic calculation processing of the present invention described so far.

  All or part of the processing described below is realized by a system processing device executing a program recorded on a predetermined medium such as a CD-ROM or a hard disk. In addition, the installation place of the processing apparatus of the system is arbitrary, and as will be described later, it may be installed in the roadside apparatus 5, may be installed in the traffic control center 3, or may be installed in the probe center 3a. There is also.

First, the processing device acquires probe data of the probe vehicle, signal switching timing information, and information on the point traffic volume of the vehicle detector 7 (step S1).
Next, the arrival traffic volume at the intersection is calculated from the stop position of the probe vehicle and the start times of the red and green lights (step S2).
Next, it is determined whether or not the arrival traffic is used for daily traffic management (step S3). If so, the data for each time of arrival traffic is statistically analyzed and stored in the memory as described above. (Step S8).

Next, correlation parameters (for example, a and b described above) between the calculated traffic volume at the intersection and the upstream traffic volume measured by the vehicle detector 7 are calculated (step S4).
The arrival traffic volume at the intersection is predicted / estimated from the correlation parameter and the point traffic volume every moment (step S5).
Next, it is determined whether or not the arrival traffic volume is used for effective signal control (step S6). If it is used, the arrival traffic volume is determined based on the presence or absence of the blue extension in the prediction signal control or the adaptive signal control. This is used to determine the traffic demand (step S9).

Next, it is determined whether or not the arrival traffic is to be used for providing information to the vehicle and automatic driving control (step S7). If so, the traffic flow behavior until the vehicle in communication arrives at the intersection is determined. Predict and provide information to the vehicle (step S10). Then, using the traffic flow behavior, the vehicle is provided with information and automatic driving control in consideration of safety and the environment (step S11).
-System configuration example-
Hereinafter, the structural example of the traffic volume calculation system of this invention is demonstrated.

First, probe data is transmitted from the probe vehicle C to the roadside device 5, signal switching timing information is transmitted from the signal control device 4 to the roadside device 5, and the system configuration in the case where the roadside device 5 calculates the arrival traffic volume at the intersection is shown. explain.
FIG. 10 is a block diagram showing the overall configuration of the traffic volume calculation system of the present invention.
The traffic volume calculation system includes an in-vehicle device 2 of the probe vehicle C, a traffic control center 3, a signal control device 4, and a roadside device 5.

The probe vehicle C includes a communication device for performing road-to-vehicle communication with the roadside device 5, a position detection device for collecting probe data, an information providing unit for providing information in consideration of safety and the environment to the driver, A vehicle-mounted device 2 including a vehicle travel control unit that performs vehicle travel control is mounted.
The said position detection apparatus is equipped with the GPS receiver etc., and can detect the position of the own vehicle for every time. The acquired position data and the like are transmitted from the communication device as probe data. The transmitted data is received by the roadside device 5.

The vehicle detector 7 measures the traffic volume at the point where it is installed. When the roadside device 5 is an optical beacon, the vehicle detector 7 may be included in the roadside device 5.
The roadside device 5 is provided with a communication device for communicating with the in-vehicle device 2 and a processing device. As shown in FIG. 10, the processing apparatus is installed in the roadside apparatus 5, but this is not always necessary, and the processing apparatus may be installed in a place different from the roadside apparatus 5. When the processing device acquires the probe data, acquires the signal switching timing information from the signal control device 4, and acquires the point traffic information from the vehicle detector 7, the processing device calculates the arrival traffic amount q. Then, traffic volume correlation analysis, arrival traffic volume prediction, and traffic flow behavior prediction are performed.

The signal control device 4 performs prediction signal control and adaptive signal control using the prediction result of the arrival traffic volume.
In addition, the traffic control center 3 communicates with the roadside device 5 to obtain arrival traffic data from the roadside device 5. The traffic control center 3 performs statistical analysis and uses it for daily traffic management.
Note that reception of probe data and transmission of traffic flow behavior prediction information may be performed by different roadside devices 5.

Next, the probe data is transmitted from the probe vehicle C to the traffic control center 3 via the roadside device 5, the point traffic information is transmitted from the vehicle detector 7 to the traffic control center 3, and the signal switching timing information is a signal. A system configuration when the traffic volume transmitted from the control device 4 to the traffic control center 3 and the traffic control center 3 calculates the arrival traffic volume at the intersection will be described.
FIG. 11 is a block diagram showing the overall configuration of this traffic volume calculation system.

The difference between the configuration of FIG. 11 and FIG. 10 will be described. Signal switching timing information is directly transmitted from the signal control device 4 to the traffic control center 3, and point traffic information is transmitted from the vehicle detector 7 to the traffic control center 3. The probe data is transmitted directly to the traffic control center 3 from the roadside device 5.
The processing device of the traffic control center 3 performs calculation of arrival traffic, correlation analysis of traffic, statistical analysis of arrival traffic, and the like.

Next, the probe data is transmitted from the probe vehicle C to the traffic control center 3 via the probe center 3a, the signal switching timing information is directly transmitted from the signal control device 4 to the traffic control center 3, and the information on the point traffic volume is A system configuration in the case where the traffic control center 3 estimates the arrival traffic volume at the intersection which is directly transmitted from the vehicle sensor 7 to the traffic control center 3 will be described.
FIG. 12 is a block diagram showing the overall configuration of this traffic volume calculation system.

Explaining the difference between the configuration of FIG. 12 and FIG. 11, there is a probe center 3a that performs wide-area communication between the probe vehicle C and a mobile phone or the like and accumulates probe data. Probe data is supplied from the probe center 3 a to the traffic control center 3.
The processing device of the traffic control center 3 performs calculation of arrival traffic volume, correlation analysis of traffic volume, statistical analysis of arrival traffic volume and the like using the probe data as described above.

Next, the probe data is transmitted from the probe vehicle C to the probe center 3a, and the signal switching timing information is transmitted from the signal control device 4 to the probe center 3a from the vehicle-mounted device 22 via the roadside device 5 and the probe vehicle C. A system configuration for estimating the arrival traffic volume at the intersection at the center 3a will be described.
FIG. 13 is a block diagram showing the overall configuration of this traffic volume calculation system.

Explaining what is different from FIG. 12, the signal switching timing information output from the signal control device 4 is transmitted to the roadside device 5, and is transmitted from the roadside device 5 to the in-vehicle device 2 of the probe vehicle C through road-to-vehicle communication. And it is transmitting to the probe center 3a via this vehicle-mounted apparatus 2.
The probe center 3a calculates the arrival traffic volume using the probe data and signal switching timing information as described above, and sends the information from the probe center 3a to the traffic control center 3.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, in providing information to a vehicle with safe driving support, it is important to provide information when there is no traffic. In this case, when the traffic flow correlation parameter is used, as shown in FIG. 14, assuming the free running speed, among the vehicles that have passed through the roadside device 5 before the information providing target vehicle, the signal at the intersection is The number of vehicles that stop after turning red can be predicted. Further, from the probe data up to immediately before, the average value of the head-to-head distance (minimum head-to-head distance) and the starting wave velocity (the average value of L / (tm−tg)) at the stop of the stop queue can be calculated. When used, it is possible to predict the stop position at which the information providing target vehicle stops in the stop queue, the stop time, the start time after the green light, the intersection passage time, and the like. In addition, various modifications can be made within the scope of the present invention.

It is a map depicting the intersection and the target road R entering the intersection. It is a graph showing the time change of a stop queue, and the behavior of the vehicle which approachs an intersection. It is a graph showing the driving | running | working behavior of one probe vehicle in an intersection. It is a schematic diagram for demonstrating the distance Lh between stop vehicle heads. It is a graph showing the driving | running | working behavior of a vehicle when two probe vehicles approach in the same signal waiting time when the intersection is congested. It is a schematic diagram for demonstrating the traffic congestion judgment method of an intersection, Fig.6 (a) is a map, FIG.6 (b) is a traffic congestion degree determination graph. It is a graph showing the driving | running | working behavior of one probe vehicle in a traffic jam intersection. It is a map which shows the road R which has an intersection and the branch road which flows into the said intersection. It is a flowchart which shows the whole procedure of the arrival traffic calculation process of this invention. It is a block diagram which shows the whole structure of the traffic volume calculation system which concerns on one Embodiment of this invention. It is a block diagram which shows the whole structure of the traffic volume calculation system which concerns on other embodiment of this invention. It is a block diagram which shows the whole structure of the traffic volume calculation system which concerns on other embodiment of this invention. It is a block diagram which shows the whole structure of the traffic volume calculation system which concerns on other embodiment of this invention. It is a graph for demonstrating the prediction method of the traffic flow in an intersection.

Explanation of symbols

2 On-vehicle device 3 Traffic control center 4 Signal control device 5 Roadside device 6 Vehicle detector 7 Vehicle detector

Claims (8)

A system for calculating arrival traffic, which is the traffic that a vehicle enters an intersection,
Probe data acquisition means for acquiring probe data including vehicle position data measured by an in-vehicle device mounted on a vehicle entering the intersection;
Signal switching timing acquisition means for acquiring signal switching timing information of a traffic light installed at the intersection;
Arrival traffic volume calculating means for calculating the arrival traffic volume of the intersection based on the vehicle position data of the vehicle acquired from the probe data acquisition means and the signal switching timing information acquired from the signal switching timing acquisition means; A traffic volume calculation system at an intersection.   The traffic volume calculation system at an intersection according to claim 1, further comprising a congestion determination unit that determines whether the intersection is congested or non-congested.   When the intersection is not congested, the arrival traffic volume calculation means uses the red signal start time and data such as the position and time at which the vehicle stopped at the end of the red signal waiting example. The traffic volume calculation system at an intersection according to claim 2, wherein the traffic volume at the intersection is calculated.   When the intersection is not congested, the arrival traffic volume calculation means calculates the red light start time, the green light start time, the time when the vehicle stops at the end of the red light waiting example, and the vehicle crosses at a green light. The traffic volume calculation system at an intersection according to claim 2, wherein the arrival traffic volume at the intersection is calculated using data on the time when the vehicle passes. A system for calculating arrival traffic, which is the traffic that a vehicle enters an intersection,
Probe data acquisition means for entering the intersection and acquiring probe data including vehicle position data measured by an in-vehicle device mounted on the vehicle;
Based on data such as the vehicle position at which the at least two vehicles stopped at the same red light acquired from the probe data acquisition means stopped at the end of the red signal waiting example and the time at which the vehicle stopped, the traffic volume at the intersection is calculated. A traffic volume calculation system at an intersection having an arrival traffic volume calculation means for calculating. Means for obtaining traffic measured by a vehicle detector upstream of the intersection;
Means for obtaining a correlation between the traffic volume measured by the vehicle sensor and the arrival traffic volume calculated by the arrival traffic volume calculation means;
The traffic volume calculation system at an intersection according to claim 1 or 5, wherein an arrival traffic volume is predicted from the correlation and the traffic volume measured by the vehicle detector. Means for obtaining traffic measured by a vehicle detector upstream of the intersection;
Means for obtaining a correlation between the traffic volume measured by the vehicle sensor and the arrival traffic volume calculated by the arrival traffic volume calculation means;
The arrival traffic volume in a time zone in which the probe data is not obtained is estimated from the correlation and the traffic volume measured by the vehicle detector in a time zone in which the probe data is not obtained. 5. Traffic volume calculation system at the intersection described in 5.   The traffic volume calculation system at an intersection according to claim 6 or 7, wherein a branch road where a vehicle flows in and out from another road exists on a road between the intersection and the vehicle detector.

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