JP5692323B1 - Traffic volume measuring apparatus and traffic volume measuring method - Google Patents

Abstract

The present invention provides a traffic measurement device that suppresses an increase in cost for system construction, operation, maintenance, and the like and improves the measurement accuracy of the number of vehicles staying in an inflow link. An inflow traffic measuring unit 22 measures the number of vehicles flowing into the link, and an outflow traffic measuring unit 23 measures the number of vehicles flowing out of the link. The staying number estimating unit 27 stays in the link by using the measured number of vehicles flowing into the link, the number of vehicles flowing out of the link, and the correction coefficient of the corresponding time zone registered in the correction coefficient correspondence table. Estimate the number of vehicles in use. Further, the correction coefficient updating unit 25 updates the correction coefficient registered in the correction coefficient correspondence table using the measured number of vehicles flowing into the link and the number of vehicles flowing out of the link. [Selection] Figure 3

Description

  The present invention relates to an apparatus for measuring the traffic volume of a vehicle on a link, and more particularly to a traffic volume measuring apparatus and a traffic volume measuring method for estimating the number of vehicles staying on the link.

  Conventionally, in order to suppress the occurrence of traffic congestion on the road network and to quickly eliminate the traffic congestion that has occurred, traffic signals that flow out to the bottleneck intersection are signaled by the inflow links at intersections where so-called traffic jams occur (so-called bottleneck intersections). The number of vehicles staying on a road that stops due to waiting or the like is measured.

  Patent Document 1 discloses that a vehicle staying in a tunnel by incrementing the counter by 1 every time a vehicle is detected on the tunnel entrance side and decrementing the counter by 1 every time the vehicle is detected on the tunnel exit side. The structure of the apparatus which measures the number of the is disclosed.

  Patent Document 2 discloses a signal control parameter (signal lamp cycle, split, offset, etc.) for controlling the display of a signal lamp installed at a bottleneck intersection according to the number of vehicles staying in the inflow link. ) Is disclosed.

JP-A-6-60292 Japanese Patent No. 4082312

However, in the configuration described in Patent Document 1, a branch path (including an intersection) through which the vehicle can flow into or out of the inflow link is connected between the inlet and the outlet of the inflow link. The number of vehicles that have flowed into the inflow link on this branch path or the number of vehicles that have flowed out of the inflow link on the branch path cannot be detected. The error that occurs is increased. That is, Patent Document 1, between the inlet and the outlet of the inflow link, vehicles are based on the assumption that this or flowed into the inflow link, the branch passage is not connected which can flow out from the inflow link. Therefore, in the configuration described in Patent Document 1, the reliability of the count value of the number of vehicles staying in the inflow link in which the branch path is connected between the inlet and the outlet cannot be ensured.

  One or more vehicle detectors are additionally installed between the inlet and outlet of the inflow link, and the number of vehicles detected at the detection position and time occupancy obtained from the vehicle detection results by these vehicle detectors. The reliability can be improved by estimating the congestion length using the rate or the like (the number of vehicles staying at the inflow link can be estimated from the congestion length). However, the addition of a vehicle detector requires an increase in the number of cables to be laid and an increase in the number of communication lines, which increases the cost for system construction, operation, maintenance, and the like.

  An object of the present invention is to provide a traffic measurement device that suppresses an increase in cost for system construction, operation, maintenance, etc., and improves the measurement accuracy of the number of vehicles staying in an inflow link. is there.

  In order to achieve the above-mentioned object, the traffic measuring device of the present invention is configured as follows.

  The inflow traffic measuring unit measures the number of vehicles flowing into the link at the entrance of the link. The outflow traffic measuring unit measures the number of vehicles flowing out from the link at the exit of the link. The inflow traffic measurement unit and the outflow traffic measurement unit use, for example, a well-known metal sensitive type (loop type, magnetic type, etc.) or solid sensitive type (ultrasonic type, radar type, etc.) vehicle sensor. The structure which measures may be sufficient, and the structure which processes the picked-up image which imaged the entrance and exit of the link, and is imaged may be sufficient.

  The correction coefficient storage unit is a correction coefficient correspondence table in which correction coefficients used for estimating the number of vehicles staying in the link are registered in association with each time zone divided by the first time (15 minutes, 20 minutes, etc.). Remember. This correction coefficient is a coefficient that matches the number of vehicles flowing into the link measured by the inflow traffic measuring unit with the number of vehicles flowing out from the link measured by the outflow traffic measuring unit. One of the number of vehicles flowing into the link measured by the unit or the number of vehicles flowing out from the link measured by the outflow traffic measurement unit is corrected. In other words, the correction coefficient is the number of vehicles flowing into the link measured by the inflow traffic measuring unit or the number of vehicles flowing out from the link measured by the outflow traffic measuring unit between the entrance and the exit of the link. Is a coefficient that is corrected according to the estimated difference in the number of vehicles that have flowed in from a branch road (including an intersection) connected to the vehicle.

  The number-of-staying-unit estimation unit is the number of vehicles measured by the inflow traffic measuring unit, the number of vehicles measured by the outflow traffic measuring unit, and the corresponding time registered in the correction coefficient correspondence table stored in the correction coefficient storage unit. Estimate the number of vehicles staying in the link using the band correction factor. As a result, the number of vehicles staying in the link can be estimated in consideration of the number of vehicles flowing in or out from the branch path connected between the entrance and exit of the link. Further, in the estimation of the number of vehicles, a measurement error of the number of vehicles in the inflow traffic measurement unit and the outflow traffic measurement unit is also taken into consideration.

  Further, the correction coefficient updating unit determines a plurality of continuous time zones associated with the correction coefficient for the correction coefficient correspondence table as the correction coefficient update period, and the inflow traffic measuring unit is in the correction coefficient update period. Using the measured number of vehicles and the number of vehicles measured by the outflow traffic volume measurement unit during the correction coefficient update period, the correction coefficient associated with each time zone belonging to the correction coefficient update period is updated.

  The number of vehicles that flow in or out from the branch path connected between the link entrance and the exit varies with time. This makes it possible to accurately calculate a correction coefficient that matches the number of vehicles flowing into the link measured by the inflow traffic measuring unit and the number of vehicles flowing out from the link measured by the outflow traffic measuring unit for each time period. It can be calculated. Therefore, the number of vehicles staying in the link can be accurately estimated.

  In addition, since it is not necessary to install a vehicle detector between the entrance and exit of the link, it is possible to suppress an increase in cost for system construction, operation, maintenance and the like.

  In addition, a state determination unit that determines whether the link is in a non-saturated state or a super-saturated state, and the correction coefficient update unit includes a correction coefficient that includes a period in which the state determination unit continuously determines that the link is in a super-saturated state. It is good also as a structure which determines an update period.

  When the vehicle is oversaturated, the number of vehicles measured at the inflow traffic measurement unit and the outflow traffic measurement unit is large, so the measurement error in the inflow traffic measurement unit and the outflow traffic measurement unit is calculated as a correction coefficient. Can be reduced. Therefore, the correction coefficient can be calculated appropriately.

  The state determination unit may be configured to determine whether the link is in a non-saturated state or a super-saturated state based on, for example, the number of outflow vehicles per unit time on the exit side of the link.

  In addition, a receiving unit that receives probe information from the in-vehicle device by wireless communication with the in-vehicle device that is mounted on the vehicle and obtains probe information indicating the traveling locus of the vehicle is provided, and the correction coefficient updating unit is a receiving unit. The correction coefficient update period including the period from the time when one of the two vehicles that have received the probe information travels on the link to the time when the other travels on the link may be determined.

  In this case, it is only necessary to determine whether the link is non-saturated or super-saturated based on the travel time of the link of the vehicle obtained from the travel locus of the vehicle that has received the probe information at the receiving unit. .

  In addition, the wireless communication device includes a receiving unit that receives the passing information of the vehicle by wireless communication with the vehicle-mounted device mounted on the vehicle, and the receiving unit receives the passing information at two locations on the near side of the link entrance and on the outer side of the link exit. The correction coefficient updating unit estimates the travel trajectory of the link for the vehicle for which the passage information is acquired by the reception unit, and from the time when one of the two vehicles that received the passage information traveled the link, the other It is good also as a structure which determines the correction coefficient update period including the period to the time which drive | worked.

  In this case, whether the link is non-saturated or super-saturated based on the travel time of the link of the vehicle obtained from the travel trajectory estimated for the vehicle that has received the passage information by the receiving unit. Can be determined.

  The correction coefficient storage unit preferably stores a correction coefficient correspondence table for each day type. The day type may be two types, for example, weekdays and holidays (Saturday, Sunday, public holidays), or may be seven types for each day of the week.

  According to the present invention, it is possible to suppress an increase in cost for system construction and operation, and to improve the measurement accuracy of the number of vehicles staying in the inflow link.

It is the schematic which shows a traffic control system. It is a block diagram which shows the structure of the principal part of a traffic control center. It is a block diagram which shows the structure of the principal part of a traffic volume measurement unit. It is a figure which shows a correction coefficient corresponding | compatible table. It is a flowchart which shows a signal control process. It is a flowchart which shows a supersaturated state determination process. It is a flowchart which shows a correction coefficient update process. Traffic observation data is acquired. It is a flowchart which shows the correction coefficient update process concerning another example. It is a figure which shows the driving | running | working locus | trajectory of the vehicle obtained from probe information. It is a flowchart which shows the correction coefficient update process concerning another example. It is a figure which shows the driving | running | working locus | trajectory of the vehicle estimated using the uplink information of an optical beacon.

  Hereinafter, a traffic volume measuring apparatus according to an embodiment of the present invention will be described.

  FIG. 1 is a schematic diagram showing a traffic control system using a traffic measuring device according to this example. In FIG. 1, two intersections A and B are illustrated.

  The traffic control center 1 includes a traffic volume measuring device (traffic volume measuring unit 12 described later) according to this embodiment. Details will be described later.

  At the intersection A, a signal lamp 5a is installed for each approach direction of the vehicle. In addition, a signal lamp 5b is installed at the intersection B for each approach direction of the vehicle. The signal control device 2a controls the display indication of the plurality of signal lamps 5a installed at the intersection A. The signal control device 2b controls the display display of the plurality of signal lamps 5b installed at the intersection B.

  In this example, the intersection A is a bottleneck intersection where traffic congestion is likely to occur. The inflow link at the intersection A shown in FIG. 1 is a road that connects the intersection B and the intersection A, and is a road on which a vehicle that passes through the intersection B and heads for the intersection A travels. Although not shown in FIG. 1, in the middle of the inflow link at the intersection A (between the intersection A and the intersection B), the vehicle can flow into or out of the inflow link. Branch roads (including intersections) are connected. There may be one or more branch paths connected to the inflow link. Therefore, among the vehicles that have passed through the intersection B and entered the inflow link of the intersection A, there are vehicles that exit from the inflow link (vehicles that do not pass through the intersection A) on the branch road that is connected on the way. In addition, there is a vehicle that does not pass through the intersection B but flows into the inflow link from a branch road that is connected on the way and passes through the intersection A.

  The vehicle detector 3a detects the passage of the vehicle flowing out from the inflow link at the intersection A to the intersection A. The vehicle detector 3a is installed near the exit of the inflow link. In addition, the vehicle detector 3b detects the passage of the vehicle flowing through the intersection B and entering the inflow link of the intersection A. The vehicle detector 3b is installed near the entrance of the inflow link. Examples of the vehicle detectors 3a and 3b include a metal sensitive type (loop type, magnetic type, etc.) and a solid sensitive type (ultrasonic type, radar type, etc.). The output of the vehicle detector 3a (vehicle detection signal) is input to the traffic control center 1 via the signal control device 2a installed near the intersection A. The output of the vehicle detector 3b (vehicle detection signal) is input to the traffic control center 1 via the signal control device 2b installed near the intersection B.

  In this example, the traffic control center 1 measures (estimates) the number of vehicles staying on the inflow link of the intersection A connecting the two intersections A and B. Further, the traffic control center 1 instructs the signal control devices 2a and 2b on signal control parameters for controlling the display of the signal lamps 5a and 5b. The signal control parameter includes a cycle indicating the time of one cycle of the signal lamps 5a and 5b, a split indicating the ratio of each indication closed in one cycle (one cycle), an offset indicating a difference in cycle start timing between intersections, and the like. included. The signal control devices 2a and 2b control the display of the signal lamps 5a and 5b based on the signal control parameters instructed from the traffic control center 1.

  FIG. 2 is a block diagram showing the configuration of the main part of the traffic control center. The traffic control center 1 includes a control unit 11, a traffic volume measurement unit 12, a signal control parameter generation unit 13, and an input / output unit 14.

  The control unit 11 controls the operation of each part of the traffic control center 1 main body.

  The traffic measurement unit 12 estimates the number of vehicles staying on the inflow link of the intersection A shown in FIG. This traffic measurement unit 12 corresponds to the traffic measurement device according to the embodiment of the present invention.

  The signal control parameter generation unit 13 displays the display indications of the signal lamps 5a and 5b installed at the intersections A and B based on the number of vehicles staying at the inflow link of the intersection A estimated by the traffic measurement unit 12. A signal control parameter to be controlled is generated.

  The input / output unit 14 inputs and outputs data with the signal control devices 2a and 2b. The output of the vehicle detector 3a (vehicle detection signal) is input to the input / output unit 14 via the signal control device 2a, and the output of the vehicle detector 3b (vehicle detection signal) is sent to the signal control device 2b. Is input via. The input / output unit 14 also outputs to the signal control devices 2a and 2b instructing signal control parameters for controlling the display of the signal lamps 5a and 5b.

  FIG. 3 is a block diagram showing the configuration of the main part of the traffic volume measurement unit. The traffic measurement unit 12 includes a control unit 21, an inflow traffic measurement unit 22, an outflow traffic measurement unit 23, a non-saturated state determination unit 24, a correction coefficient update unit 25, a correction coefficient storage unit 26, And a staying number estimating unit 27.

  The control unit 21 controls the operation of each part of the traffic volume measuring unit 12 main body. The control unit 21 communicates with the control unit 11.

  The inflow traffic measuring unit 22 counts the output (vehicle detection signal) of the vehicle detector 3b input via the signal control device 2b, and flows into the inflow link of the intersection A through the intersection B. Measure the number of vehicles.

  The outflow traffic measuring unit 23 counts the number of vehicles that have flowed into the intersection A from the inflow link of the intersection A by counting the output (vehicle detection signal) of the vehicle detector 3a input via the signal control device 2a. Measure.

  The non-saturated state determination unit 24 determines whether the state of the inflow link at the intersection A is a non-saturated state or a super-saturated state. The non-saturated state is a state where there is no traffic jam, and the super-saturated state is a state where there is a traffic jam.

  The correction coefficient updating unit 25 calculates a correction coefficient used for estimating the number of vehicles staying on the inflow link of the intersection A.

  The correction coefficient storage unit 26 stores a correction coefficient correspondence table in which the correction coefficient calculated by the correction coefficient update unit 25 is registered for each day type. In this example, there are two day types, weekdays and holidays, and a correction coefficient correspondence table for weekdays and holidays is stored in the correction coefficient storage unit 26 as shown in FIG. The correction coefficient correspondence table associates correction coefficients for each time zone. The example shown in FIG. 4 is a correction coefficient correspondence table in which correction coefficients are associated with each time zone divided at 15-minute intervals.

  The correction coefficient correspondence table stored in the correction coefficient storage unit 26 may be seven for each day of the week, and the time zone classification is not limited to 15 minutes, but may be 5 minutes, 10 minutes, 20 minutes, or the like. May be.

  The staying number estimating unit 27 includes a correction coefficient correspondence table stored in the correction coefficient storage unit 26, the number of vehicles that have passed through the intersection B measured by the inflow traffic measuring unit 22 and entered the inflow link of the intersection A, and the outflow The number of vehicles staying at the inflow link of the intersection A is estimated using the number of vehicles that have flowed out from the inflow link of the intersection A to the intersection A measured by the traffic measuring unit 23.

  Next, the operation of the traffic control system according to this example will be described. The traffic control system according to this example includes a signal control process for controlling the display of the signal lamps 5a and 5b in the traffic control center 1, and a correction coefficient update process for updating the correction coefficient correspondence table stored in the correction coefficient storage unit 26. I do.

  First, signal control processing for controlling the display of the signal lamps 5a and 5b will be described. FIG. 5 is a flowchart showing this signal control processing. The traffic control center 1 instructs the signal control parameters to the signal control devices 2a and 2b. In this example, the traffic control center 1 generates an instructed signal control parameter for each of the signal control devices 2a and 2b. The signal control device 2a controls the display of the signal lamp 5a with the signal control parameter instructed from the traffic control center 1. The signal control device 2b controls the display of the signal lamp 5b with the signal control parameter instructed from the traffic control center 1.

  The traffic control center 1 determines whether the inflow link at the intersection A shown in FIG. 1 is in a non-saturated state or a super-saturated state (s1). That is, in s1, it is determined whether the inflow link at the intersection A is congested. The determination relating to s1 is performed by the traffic measurement unit 12 based on the blue hour utilization rate of the vehicle group flowing out from the inflow link at the intersection A to the intersection A.

  The green hour utilization rate can be calculated by the following formula.

Blue hour utilization rate = number of spills / (blue hour x saturated traffic flow rate)
The number of outflows is the number of vehicles that have flowed out to the intersection A from the inflow link of the intersection A in one cycle of the signal lamp 5a (actually, the blue time in one cycle of the signal lamp 5a). The number of outflows is obtained by counting the vehicle detection signal of the vehicle detector 3a input by the outflow traffic measuring unit 23 via the signal control device 2a.

  The blue time is the time when the current indication is the vehicle group of the inflow link at the intersection A in one cycle of the signal lamp 5a. Here, it is assumed that the vehicle group of the inflow link at the intersection A does not enter the intersection A in a time zone other than the blue hour in one cycle of the signal lamp 5a. Therefore, (number of outflows / blue time) is the number of vehicles per unit time that have flowed out from the inflow link of intersection A to intersection A.

The saturation traffic flow rate is the maximum number of vehicles that can flow out to the intersection A from the inflow link of the intersection A per unit time (1 sec). This saturated traffic flow rate may be a fixed value set in advance or a value acquired by the traffic volume measurement unit 12 through learning. In the learning of the saturated traffic flow rate , when the inflow link at the intersection A is in a supersaturated state, the number of vehicles that have flowed out from this link to the intersection A may be measured and calculated by the following equation.

Saturated traffic flow rate = number of spills / blue hours In addition, the saturated traffic flow rate calculated by the above formula varies depending on the mixing rate of large vehicles, so it is preferable to determine by day type and time zone.

  FIG. 6 is a flowchart showing the supersaturated state determination process according to s1. The traffic volume measuring unit 12 calculates the blue hour utilization rate in the previous cycle of the signal lamp 5a in the control unit 21 (s11). The green hour utilization rate increases as the number of vehicles staying on the inflow link at the intersection A increases, that is, increases as the vehicle is congested, and takes a value of around 1 in a traffic jam.

  If the previous determination is an oversaturated state for the inflow link at the intersection A, the control unit 21 compares the blue hour utilization rate calculated in s11 with the first determination value α (s12, s13). If the previous determination is non-saturated for the inflow link at the intersection A, the control unit 21 compares the green time utilization rate calculated in s11 with the second determination value β (s12, s14). The first determination value α is smaller than the second determination value β (first determination value α <second determination value β). For example, the first determination value α is 0.85, and the second determination value β is 0.90.

  When the control unit 21 determines in s13 that the blue hour utilization rate calculated in s11 is less than the first determination value α, the control unit 21 determines that the inflow link at the intersection A is in an unsaturated state (s15). Conversely, if the control unit 21 determines in s13 that the blue hour utilization rate calculated in s11 is equal to or greater than the first determination value α, the control unit 21 determines that the inflow link at the intersection A is in a supersaturated state (s16).

  In addition, when the control unit 21 determines in s14 that the blue hour usage rate calculated in s11 is less than the second determination value β, the control unit 21 determines that the inflow link of the intersection A is in an unsaturated state (s17). Conversely, if the control unit 21 determines in s14 that the blue hour utilization rate calculated in s11 is equal to or greater than the second determination value β, the control unit 21 determines that the inflow link at the intersection A is in a supersaturated state (s18).

  In the process shown in FIG. 6, by using the first determination value α and the second determination value β described above, it is possible to determine whether the inflow link of the intersection A is in a non-saturated state or a super-saturated state. Has hysteresis. Thereby, about the inflow link of the intersection A, it suppresses that the determination result of a non-saturated state and a supersaturated state changes for every process of s1.

  Returning to FIG. 5, the traffic measurement unit 12 estimates the number of vehicles staying in the inflow link of the intersection A (s2). The number of vehicles staying is the intersection estimated by passing through the intersection estimated by the inflow traffic measuring unit 22 in the previous cycle of the signal lamp 5a and the correction coefficient correspondence table stored in the correction coefficient storage unit 26 and the previous estimated number of staying vehicles. The number of vehicles flowing into the intersection A using the number of vehicles flowing into the inflow link and the number of vehicles flowing into the intersection A from the inflow link of the intersection A measured by the outflow traffic measuring unit 23 in the previous cycle of the signal lamp 5a. Estimate the number of vehicles staying at the inflow link.

In particular,
Number of vehicles staying = (previously estimated number of stays) + (number of vehicles passing through the intersection B measured by the inflow traffic measuring unit 22 in the previous cycle of the signal lamp 5a and flowing into the inflow link of the intersection A x correspondence Correction coefficient)-(the number of vehicles that have flowed out to the intersection A from the inflow link of the intersection A measured by the outflow traffic measurement unit 23 in the previous cycle of the signal lamp 5a)
Estimated by

  The corresponding correction coefficient used in the above estimation is a correction coefficient whose day type and time zone correspond to the previous cycle of the signal lamp 5a.

  Details of the correction coefficient will be described later. In this example, the correction coefficient matches the number of vehicles that have passed through the intersection B and entered the inflow link of the intersection A with the number of vehicles that have flowed out of the inflow link to the intersection A. That is, the correction coefficient is calculated based on the number of vehicles passing through the intersection B and flowing into the inflow link at the intersection A, with the vehicles flowing in from the branch path connected between the entrance and the exit of the link. This is a coefficient to be corrected according to the estimated difference in the number of vehicles.

  In s2, if the estimated number of vehicles is a negative value, it is estimated to be 0.

  The traffic measurement unit 12 generates the signal control parameter based on the state of the inflow link at the intersection A determined in s1 (non-saturated or oversaturated) and the number of vehicles staying in the inflow link at the intersection A estimated in s2. Notify unit 13. The signal control parameter generation unit 13 performs signal control parameter generation processing for generating signal control parameters for controlling the signal lamps 5a and 5b based on the notification from the traffic volume measurement unit 12 (s3).

  In the signal control parameter generation processing according to s3, for example, the maximum value of the load factor of each inflow link is obtained for each indication, and the signal lamp 5a is obtained by a known load factor distribution method in which the split is distributed by the ratio of the indication load factor. 5b is generated. Also, other methods such as selecting one of the signal control parameters from a plurality of preset signal control parameters may be used.

  In addition, if the inflow link at the intersection A is in a supersaturated state, a known method of calculating the maximum travel time of each inflow link for each display based on the estimated number of vehicles and allocating splits by the travel time ratio The signal control parameters for controlling the signal lamps 5a and 5b are generated by (for example, the method described in Patent Document 2 described above). Moreover, according to the estimated number of vehicles staying in the inflow link of the intersection A notified this time, the vehicle group flowing out to the intersection A from the inflow link is selected from a plurality of preset signal control parameters. Other methods, such as selecting a signal control parameter that lengthens the display, may be used.

  In the input / output unit 14, the traffic control center 1 transmits the signal control parameter generated by the signal control parameter generation unit 13 in s3 to the signal control devices 2a and 2b (s4).

  The traffic control center 1 returns to s1 when the display of the signal lamp 5a is completed for one cycle (s5), and repeats the above-described processing.

As described above, the traffic volume measuring unit 12 estimates the number of vehicles staying in the inflow link of the intersection A for each cycle of the signal lamp 5a. Further, the traffic volume measurement unit 12 may calculate and output the traffic jam length at the inflow link of the intersection A from the estimated number of vehicles. The traffic jam head
Congestion length = Estimated number of stays x Average vehicle head distance (eg 7m)
Can be calculated.

  Next, the correction coefficient update process will be described. This correction coefficient update process is executed, for example, at midnight when the date changes.

  FIG. 7 is a flowchart showing this correction coefficient update processing. The traffic control center 1 acquires the traffic volume observation data shown in FIG. 8 in the signal control process on the previous day. This traffic volume observation data includes the number of vehicles detected by the vehicle detector 3b (the number of inflows) and the vehicle detector 3a for each time zone associated with the correction coefficient in the correction coefficient correspondence table shown in FIG. The number of detected vehicles (number of outflows) is associated with the state of the inflow link (non-saturated or over-saturated) determined in s1 described above.

  In addition, since the determination concerning the above-mentioned s1 is performed for every cycle of the signal lamp 5a as described above, it is performed a plurality of times in the time zone in which the traffic volume observation data is divided. For this reason, the state (non-saturated or super-saturated) in the traffic observation data is over-saturated if the number of times determined to be super-saturated in the above-mentioned s1 in the corresponding time zone is equal to or greater than the predetermined number of times. If it is less than a predetermined number of times, it is not saturated.

  The traffic measurement unit 12 determines a correction target period for updating the correction coefficient based on the traffic observation data of the previous day (s21). In s21, a time zone in which the supersaturated state is continuous (in the example shown in FIG. 8, 7:30 to 8:15) and two time zones in the non-saturated state are set as the correction target period. The two non-saturated states are time zones that sandwich a time zone in which the super-saturated state continues. In the example illustrated in FIG. 8, six consecutive time zones from 7:15 to 8:30 are determined as the correction target periods.

  Note that the correction target period determined in s21 is not necessarily one.

  The traffic volume measurement unit 12 performs the processing after s22 shown below for each correction target period determined in s21.

  The traffic volume measurement unit 12 calculates the total number of vehicles detected by the vehicle detector 3b (total number of inflows) during the correction target period (s22). In the example shown in FIG. 8, the total number of inflows is 730 (145 + 170 + 140 + 85 + 95 + 95). Further, the traffic volume measuring unit 12 calculates the total number of vehicles (total number of outflows) detected by the vehicle detector 3a during the correction target period (s23). In the example shown in FIG. 8, the total number of outflows is 790 (135 + 135 + 135 + 135 + 135 + 115).

  For each time zone belonging to the correction target period, an update coefficient used to update the associated correction coefficient is calculated (s24). This update coefficient is a value obtained by dividing the total number of outflows calculated in s23 by the total number of inflows calculated in s22 (total number of outflows / total number of inflows). That is, the update coefficient is a coefficient that corrects the total number of inflows calculated in s22 and makes the corrected number coincide with the total number of outflows calculated in s23.

  The traffic measurement unit 12 updates the correction coefficient associated with the time zone using the update coefficient calculated in s24 for each time zone belonging to the correction target period (s25). In s25, a new correction coefficient is calculated by the following formula, and the correction coefficient for the corresponding time zone registered in the correction coefficient correspondence table is replaced with the calculated value.

New correction coefficient = current correction coefficient × (1−smoothing coefficient) + update coefficient calculated by s24 × smoothing coefficient The smoothing coefficient suppresses the influence of the measurement result of the previous day on the new correction coefficient to some extent, and the correction coefficient In order to suppress the fluctuation range, it is preferable to set in the range of 0.2 to 0.4.

  Thus, in this correction coefficient update process, a correction coefficient that matches the number of vehicles that have passed through the intersection B and entered the inflow link of the intersection A with the number of vehicles that have flowed out of the inflow link to the intersection A is obtained. That is, the number of vehicles flowing out from this inflow link (vehicles that do not pass through intersection A) and the flow into this inflow link on the branch road that is connected to the middle of the inflow link at intersection A (between intersection A and intersection B) The number of vehicles that have flowed into the inflow link can be corrected in consideration of the number of vehicles (vehicles that have not passed through the intersection B). Therefore, it is possible to accurately estimate the number of vehicles staying in the inflow link.

  When the vehicle is in a supersaturated state, the number of vehicles measured by the inflow traffic measuring unit 22 and the outflow traffic measuring unit 23 is large. Therefore, measurement errors in the inflow traffic measuring unit 22 and the outflow traffic measuring unit 23 are measured. However, since the influence on the calculated update coefficient can be suppressed, a new correction coefficient can be calculated appropriately.

  Furthermore, in this example, as described above, the correction target period determined in s21 is a time period sandwiched between two time periods in which the supersaturated state is continuous and the two nonsaturated states. That is, the time zone at the start time and end time of the correction target period determined in s21 is in a non-saturated state. For this reason, the number of vehicles staying at the start point and end point of the correction target period in the inflow link is substantially the same number (there is no significant difference). Accordingly, since the influence of the difference in the number of staying vehicles at the start time and the end time of the correction target period on the update coefficient to be calculated can be suppressed, a new correction coefficient can be calculated more appropriately.

  Further, it is only necessary to provide the vehicle detectors 3a and 3b at both ends of the inflow link, and it is not necessary to provide the vehicle sensor in the middle of the inflow link, so that the cost for system construction, operation and maintenance can be sufficiently suppressed. It is done.

  In the above example, the vehicle detectors 3a and 3b detect a vehicle that has flowed out of the link or a vehicle that has flowed into the link. It is good also as a structure which detects the vehicle which flowed out from the vehicle, and the vehicle which flowed into the link.

  Next, another example will be described. In this example, the correction coefficient is updated using probe information acquired from a vehicle traveling on the link. In this example, a wireless communication terminal that performs wireless communication with an on-vehicle probe mounted on a vehicle is installed at an intersection A. The probe on-board device has a GPS positioning function as is well known, and measures the current position periodically (every fixed time or every fixed distance) and stores time, latitude, and longitude in association with each other. It is a device that acquires trajectory information.

  The wireless communication terminal acquires the traveling locus information of the vehicle stored in the on-vehicle probe device by wireless communication with the on-vehicle probe device. This wireless communication terminal notifies the traffic control center 1 of the acquired travel locus information.

  The traffic control system according to this example also performs the signal control processing shown in FIG. In addition, the traffic control center 1 acquires travel locus information of a vehicle equipped with the on-vehicle probe device from a wireless communication terminal.

  FIG. 9 is a flowchart showing correction coefficient update processing according to this example.

  The traffic control center 1 according to this example acquires traffic volume observation data in which the time at which the vehicle detectors 3a and 3b detect the vehicle is stored for each of the vehicle detectors 3a and 3b. That is, the passing time of each vehicle in the sensing area of the vehicle detectors 3a and 3b is acquired as traffic volume observation data.

  In the correction coefficient update process, the traveling locus information acquired from the on-vehicle probe device is arranged in time series, and the previous day is divided into a plurality of time zones at intervals of about 30 minutes to 2 hours (s31). In s31, the time zone is classified based on the time when it flows into the inflow link of the intersection A (the time when it passes through the sensing area of the vehicle detector 3b). The start time and end time of the time zone divided here are times when the vehicle equipped with the on-vehicle probe passes through the sensing area of the vehicle detector 3b. Between the start time and the end time of one time zone divided by s31, the travel locus information acquired from the probe onboard equipment mounted on the other vehicle may be included. Each time zone divided here is the correction target period in the above example.

  The traffic volume measurement unit 12 performs the processing after s32 shown below for each correction target period determined in s31.

  FIG. 10 is a diagram illustrating the travel trajectories of the first vehicle X and the last vehicle Y in one correction target period divided by s31. This traveling locus is obtained from traveling locus information acquired from the probe on-vehicle device. The traffic measurement unit 12 obtains the total number of vehicles detected by the vehicle detector 3b between the leading vehicle X and the last vehicle Y as the total number of inflows (s32). Further, the traffic volume measurement unit 12 obtains the number of vehicles detected by the vehicle detector 3a between the leading vehicle X and the last vehicle Y as the total number of outflows (s33). As described above, in this example, the passing time of each vehicle in the sensing area of the vehicle detectors 3a and 3b is acquired as traffic volume observation data. Further, the passage time when the leading vehicle X and the last vehicle Y have passed through the sensing areas of the vehicle detectors 3a and 3b can be obtained from the travel locus information. Therefore, in s32 and s33, by referring to the traffic volume observation data, the total number of inflows detected by the vehicle detector 3b and the vehicle detector 3a are detected between the leading vehicle X and the last vehicle Y. The total number of outflows can be obtained.

  For each correction target period, the traffic volume measurement unit 12 calculates an update coefficient for updating the correction coefficient associated with each time zone belonging to the correction target period (s34). This update coefficient is a value obtained by dividing the total number of outflows obtained in s33 by the total number of inflows obtained in s32 (total number of outflows obtained in s33 / total number of inflows obtained in s32).

  The traffic volume measuring unit 12 updates the correction coefficient associated with the time zone using the update coefficient calculated in s34 for each time zone belonging to the correction target period (s35). In s35, a new correction coefficient is calculated by the following equation, and the correction coefficient for the corresponding time zone registered in the correction coefficient correspondence table is replaced with the calculated value.

New correction coefficient = current correction coefficient × (1−smoothing coefficient) + update coefficient calculated by s34 × smoothing coefficient As for the smoothing coefficient, the measurement result of the previous day gives the new correction coefficient as in the above example. In order to suppress the influence to some extent and suppress the fluctuation range of the correction coefficient, it is preferable to set in the range of 0.2 to 0.4.

  In this example, in the correction coefficient correspondence table, since the correction target period is not defined in the time zone classification in which the correction coefficient is associated, the time period belonging to both of the two correction target periods that are temporally continuous (The time zone in which the correction coefficient is associated). The time zones that belong to both of the two correction target periods that are temporally continuous (the time slot with which the correction coefficient is associated) are included in one of the correction target periods and not included in the other correction target period. For example, a time zone that belongs to both of two correction target periods that are temporally continuous (a time slot that is associated with a correction coefficient) is included in a correction target period that has a longer time period.

  In this example, the correction coefficient can also be updated for a time zone in which the inflow link at the intersection A is in a non-saturated state.

  Next, another example will be described. In this example, the correction coefficient is updated using the uplink information of the optical beacon. In this example, on both sides of the inflow link at intersection A (inflow side and outflow side), receiving terminals that perform wireless communication with the on-vehicle device compatible with the optical beacon and receive the uplink information of the optical beacon are installed. The optical beacon uplink information output from the optical beacon-supported vehicle-mounted device is information including the vehicle ID and the passage time. The receiving terminal notifies the traffic control center 1 of the uplink information of the received optical beacon.

  The traffic control system according to this example also performs the signal control process shown in FIG. Further, the traffic control center 1 is acquired from the optical beacon uplink information receiving terminal.

  FIG. 11 is a flowchart showing correction coefficient update processing according to this example. The traffic control center 1 according to this example acquires traffic volume observation data in which the time at which the vehicle detectors 3a and 3b detect the vehicle is stored for each of the vehicle detectors 3a and 3b. That is, the passing time of each vehicle in the sensing area of the vehicle detectors 3a and 3b is acquired as traffic volume observation data.

  In the correction coefficient update process, the optical beacon uplink information acquired from the optical beacon-supported vehicle-mounted device is arranged in time series, and the travel locus is estimated for each vehicle from which the uplink information has been acquired (s41). In s41, it is assumed that the vehicle has traveled at a constant speed between the two points on the inflow side and the outflow side (between receiving terminal installations) from which uplink information has been acquired, and the travel locus is estimated. The traffic volume measurement unit 12 sorts the previous day into a plurality of time zones at intervals of about 1.5 hours to 3 hours, in a time series, based on the travel trajectory of the vehicle estimated in s41 (s42). In s42, the time zone is classified based on the estimated time (time when passing through the sensing area of the vehicle detector 3b) flowing into the inflow link of the intersection A. The start time and end time of the time zone divided here are times when a vehicle equipped with the optical beacon-supported vehicle-mounted device passes through the sensing area of the vehicle detector 3b. Between the start time and end time of one time zone divided by s42, the uplink information acquired from the optical beacon-supported vehicle-mounted device mounted on another vehicle may be included. Each time zone divided here is the correction target period in the above example.

  The traffic volume measurement unit 12 performs the processing after s43 shown below for each correction target period determined in s42.

  FIG. 11 is a diagram showing the estimated traveling trajectories of the first vehicle X and the last vehicle Y in one correction target period divided by s42. This estimated traveling locus is the one estimated in s41. The traffic volume measurement unit 12 obtains the number of vehicles detected by the vehicle detector 3b between the leading vehicle X and the last vehicle Y as the total number of inflows (s43). Further, the traffic volume measurement unit 12 obtains the number of vehicles detected by the vehicle detector 3a as the total number of outflows between the leading vehicle X and the last vehicle Y (s44). As described above, in this example, the passing time of each vehicle in the sensing area of the vehicle detectors 3a and 3b is acquired as traffic volume observation data. Further, the passing time when the leading vehicle X and the last vehicle Y pass through the sensing areas of the vehicle detectors 3a and 3b is obtained from the estimated traveling locus. Therefore, in s32 and s33, using the traffic volume observation data, the total number of inflows detected by the vehicle detector 3b and the outflow detected by the vehicle detector 3a between the leading vehicle X and the last vehicle Y are detected. The total number can be obtained.

  For each correction target period, the traffic volume measurement unit 12 calculates an update coefficient for updating the correction coefficient associated with each time zone belonging to the correction target period (s45). This update coefficient is a value obtained by dividing the total number of outflows obtained in s44 by the total number of inflows obtained in s43 (total number of outflows obtained in s44 / total number of inflows obtained in s43).

  The traffic measurement unit 12 updates the correction coefficient associated with the time zone using the update coefficient calculated in s45 for each time zone belonging to the correction target period (s46). In s46, a new correction coefficient is calculated by the following formula, and the correction coefficient for the corresponding time zone registered in the correction coefficient correspondence table is replaced with the calculated value.

New correction coefficient = current correction coefficient × (1−smoothing coefficient) + update coefficient calculated by s45 × smoothing coefficient As with the above example, the smoothing coefficient gives the new correction coefficient the measurement result of the previous day. In order to suppress the influence to some extent and suppress the fluctuation range of the correction coefficient, it is preferable to set in the range of 0.2 to 0.4.

  In this example, in the correction coefficient correspondence table, since the correction target period is not defined in the time zone classification in which the correction coefficient is associated, the time periods belonging to both of the two correction target periods that are temporally continuous ( There is also a time zone in which correction coefficients are associated. The time zones that belong to both of the two correction target periods that are temporally continuous (the time slot with which the correction coefficient is associated) are included in one of the correction target periods and not included in the other correction target period. For example, a time zone that belongs to both of two correction target periods that are temporally continuous (a time slot that is associated with a correction coefficient) may be included in a correction target period that has a longer time period.

  Even in this configuration, the correction coefficient can be appropriately updated even in a time zone in which the inflow link at the intersection A is in a non-saturated state, so that the number of vehicles staying in the inflow link can be estimated with higher accuracy.

Further, in the above-described example, the determination relating to s1 is determined based on the blue hour utilization rate. However, a configuration in which the traveling locus information acquired from the on-vehicle probe device is used may be employed. Specifically, it is determined that the actual traveling time of the vehicle on the inflow link at the intersection A is non-saturated from the traveling locus of the on-vehicle probe device, and is unsaturated if it is shorter than the predetermined time. Judge that there is. The time used for this determination may be assumed to be one or less signal stops during traveling of the inflow link at intersection A. Specifically, the addition time of the first time required to travel the inflow link of the intersection A at the set speed and the cycle of the signal lamp 5a is set to a predetermined time,
If the actual travel time obtained from the travel trajectory information> the first time + the cycle of the signal lamp 5a, it is determined to be a supersaturated state, and if not, it is determined to be a non-saturated state.

  In this case, it is a condition that the vehicle equipped with the on-vehicle probe travels the inflow link at the intersection A at an appropriate time interval. In other words, in a situation where a vehicle equipped with the on-vehicle probe hardly travels the inflow link at the intersection A, it is hardly determined whether the inflow link is in a non-saturated state or a supersaturated state.

  Moreover, you may perform the determination concerning s1 with the uplink information of an optical beacon. In this case, from the uplink information acquired from the optical beacon-supported vehicle-mounted device, the travel trajectory of the vehicle equipped with this optical beacon-supported vehicle-mounted device is estimated, and the estimated travel time of the vehicle on the inflow link at the intersection A is estimated. If it is shorter than the predetermined time, it is determined that the state is not saturated, and if it is longer, it is determined that the state is supersaturated.

Similarly to the above example, the time used for this determination may be assumed that the signal stop is less than once in the traveling of the inflow link at the intersection A. Specifically, the addition time of the first time required to travel the inflow link of the intersection A at the set speed and the cycle of the signal lamp 5a is set to a predetermined time,
If it is the travel time estimated from the uplink information> the first time + the cycle of the signal lamp 5a, it is determined to be a supersaturated state, and if not, it is determined to be a non-saturated state.

  In this case as well, it is a condition that the vehicle on which the optical beacon on-vehicle device is mounted travels the inflow link of the intersection A at an appropriate time interval.

  Further, when the probe information is acquired from the probe on-vehicle device, the above-described estimation process of the number of traffic jams in s2 may be calculated using the traveling locus of the vehicle indicated by the probe information.

For example, using the vehicle travel time at the inflow link of intersection A, the number of vehicles staying = (vehicle travel time−set travel time at non-saturation) / intersection passage time per vehicle The set travel time at non-saturation is ( The length of the inflow link at the intersection A / the average speed of the vehicle may be set.

  The intersection passage time per vehicle is signal period / (blue time × saturated traffic flow rate).

  Also, instead of the probe information, the number of traffic jams is estimated using the travel time of the vehicle at the inflow link of the intersection A obtained from the travel track of the vehicle estimated using the uplink information acquired from the on-vehicle device corresponding to the optical beacon. May be.

  Further, the timing at which the number of traffic jams is estimated using the traveling locus of the vehicle indicated by the probe information acquired from the probe on-vehicle device is determined in the above-described s21 related to this processing when the correction coefficient update processing shown in FIG. 7 is executed. It is preferable to set the end time or start time of the correction target period.

  In the above-described example, the number of vehicles flowing out from the inflow link of the intersection A to the intersection A is used as a reference, the number of vehicles detected by the vehicle detector 3b is corrected, and the branch road connected in the middle of the inflow link In consideration of the inflow, outflow, etc. of the vehicle, the number of vehicles detected by the vehicle detector 3a is corrected based on the number of vehicles flowing through the intersection B to the inflow link of the intersection A, It is good also as a structure which considers the inflow, outflow, etc. of the vehicle in the branch road connected in the middle of this inflow link.

  In the above example, the inflow link at the intersection A is described as one lane, but two or more lanes may be used.

Further, the traffic control center 1 may be configured to calculate and output the traffic jam length of a vehicle staying at the inflow link of the intersection A, the travel time of the inflow link, and the like.

DESCRIPTION OF SYMBOLS 1 ... Traffic control center 2a, 2b ... Signal control apparatus 3a, 3b ... Vehicle detector 5a, 5b ... Signal lamp 11 ... Control unit 12 ... Traffic volume measurement unit 13 ... Signal control parameter generation unit 14 ... Input / output unit 21 ... Control Unit 22 ... Inflow traffic measurement unit 23 ... Outflow traffic measurement unit 24 ... Unsaturated state determination unit 25 ... Correction coefficient update unit 26 ... Correction coefficient storage unit 27 ... Number of staying number estimation unit

Claims (9)

An inflow traffic measuring unit that measures the number of vehicles flowing into the link at the entrance of the link;
At the exit of the link, an outflow traffic measuring unit that measures the number of vehicles flowing out of the link,
A correction coefficient storage unit that stores a correction coefficient correspondence table in which correction coefficients used for estimating the number of vehicles staying in the link are registered in association with each time period divided by the first time;
The number of vehicles measured by the inflow traffic measuring unit, the number of vehicles measured by the outflow traffic measuring unit, and the corresponding time zone registered in the correction coefficient correspondence table stored in the correction coefficient storage unit. A staying number estimating unit that estimates the number of vehicles staying in the link using a correction coefficient;
For the correction coefficient correspondence table, a plurality of continuous time zones associated with correction coefficients are determined as a correction coefficient update period, and the number of vehicles measured by the inflow traffic measuring unit during the correction coefficient update period And a correction coefficient update unit that updates a correction coefficient associated with each time zone belonging to the correction coefficient update period using the number of vehicles measured by the outflow traffic volume measurement unit during the correction coefficient update period. And a traffic volume measuring device. A state determination unit for determining whether the link is in a non-saturated state or a super-saturated state;
The traffic volume measuring device according to claim 1, wherein the correction coefficient update unit determines a correction coefficient update period including a period in which the state determination unit continuously determines that the state is a supersaturated state.   The traffic according to claim 2, wherein the state determination unit determines whether the link is in a non-saturated state or a super-saturated state based on the number of outflows of vehicles per unit time on the exit side of the link. Quantity measuring device. A receiving unit that is mounted on a vehicle and receives probe information from the in-vehicle device by wireless communication with the in-vehicle device that acquires probe information indicating the travel locus of the vehicle,
The correction coefficient update unit determines a correction coefficient update period including a period from a time when one of the two vehicles having received the probe information by the reception unit travels the link to a time when the other travels the link. The traffic volume measuring device according to claim 1.   A state determination unit that determines whether the link is in a non-saturated state or a super-saturated state based on the travel time of the link of the vehicle obtained from the travel locus of the vehicle that has received the probe information by the receiving unit. The traffic volume measuring device according to claim 4, comprising: A receiver that receives the passing information of the vehicle by wireless communication with the vehicle-mounted device mounted on the vehicle,
The receiving unit receives passage information at two locations on the near side of the link entrance and on the outside of the link exit,
The correction coefficient updating unit estimates a travel trajectory of the link for the vehicle for which the passage information is acquired by the reception unit, and from the time when one of the two vehicles that have received the passage information travels the link, the other is the The traffic measurement device according to claim 1, wherein a correction coefficient update period including a period up to a time when the link travels is determined.   Whether the link is non-saturated or super-saturated based on the travel time of the link of the vehicle obtained from the travel locus of the vehicle estimated for the vehicle that has received the passage information by the receiver. The traffic volume measuring device according to claim 6, further comprising a state determination unit for determining.   The traffic volume measuring device according to claim 1, wherein the correction coefficient storage unit stores the correction coefficient correspondence table for each day type. For each time zone divided by the first time, a correction coefficient correspondence table in which correction coefficients used for estimating the number of vehicles staying in the link are associated and registered is stored in the correction coefficient storage unit,
Inflow traffic measurement step for measuring the number of vehicles flowing into the link at the entrance of the link;
An outflow traffic measurement step for measuring the number of vehicles flowing out from the link at the exit of the link;
The number of vehicles measured in the inflow traffic measurement step, the number of vehicles measured in the outflow traffic measurement step, and the corresponding time zone registered in the correction coefficient correspondence table stored in the correction coefficient storage unit. A staying number estimating step for estimating the number of vehicles staying in the link using a correction coefficient;
The number of vehicles measured in the correction coefficient update period in the inflow traffic volume measurement step, wherein a plurality of continuous time zones associated with correction coefficients are determined in the correction coefficient update period in the correction coefficient correspondence table. And a correction coefficient update step of updating a correction coefficient associated with each time zone belonging to the correction coefficient update period, using the number of vehicles measured in the correction coefficient update period in the outflow traffic measurement step And a traffic measurement method comprising:

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