JP2010205205A - Signal controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal controller which prevents decrease of traffic flow ratio at an intersection by preventing a large vehicle from being a signal-waiting head vehicle. <P>SOLUTION: The signal controller 1 determines the average speed of the vehicle at an inflow link and whether or not the vehicle is a large vehicle, using a vehicle sensing signal as output of a sensor 11. The signal controller 1 determines whether or not the large vehicle having passed through the sensing place of the sensor 11 could be the signal-waiting head vehicle at the intersection, and if it determines that the vehicle could be the head vehicle, it extends the main aspect of a current cycle to pass the large vehicle without stopping at the intersection. Thereby, the large vehicle, such as a truck or an autobus is prevented from being the head of the signal-waiting stopping vehicles at the intersection. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a signal control device that controls a display indication of a traffic light installed at an intersection.

  Conventionally, a signal control device controls the display of a traffic light installed at an intersection based on a set signal control parameter. Signal control parameters include cycle, split, offset and the like. The cycle is the time of one period of the signal lamp, and the split is the ratio of each display in one cycle (one period). The offset is a difference in cycle start timing between intersections.

  The signal control parameters need to be set appropriately according to the traffic situation of the installed intersection. Specifically, the signal control parameters are the traffic demand and saturation traffic flow rate so that the red time is not too long and the blue time is not too short for the vehicle group traveling in each direction at the intersection. It is necessary to set with good balance in consideration of In short, the saturated traffic flow rate is the maximum number of vehicles that can pass through an intersection per unit time. It is known that this saturated traffic flow rate varies depending on traffic conditions, road conditions, weather conditions, etc., and also varies depending on the size and performance of passing vehicles, driver skill, and regional characteristics (Non-Patent Documents). 1). Therefore, as described in Non-Patent Document 1, the saturated traffic flow rate is preferably based on actual measurement results. Moreover, in patent document 1, the number of passing vehicles sandwiched between these two vehicles is obtained by acquiring the traveling locus of the vehicle by wireless communication with the two vehicles on which the probe on-vehicle device is mounted. It has been proposed to measure and calculate traffic flow parameters including saturated traffic flow rate.

JP 2007-241429 A

"Revised Traffic Signal Guide" Traffic Engineering Research Group, edited and published. Maruzen Co., Ltd. July 2006

  However, large vehicles such as trucks and buses have poor acceleration at the time of starting (acceleration is small) as compared to ordinary vehicles. For this reason, when the leading vehicle waiting for a signal at an intersection becomes a large vehicle, it changes to a green light, and the time required for the traveling speed of the vehicle group given the indication to stabilize becomes longer. Therefore, if the leading vehicle waiting for a signal at an intersection becomes a large vehicle, the traffic flow rate at the intersection will be reduced.

  Note that signal control (bus priority control) for extending the present display of the bus and passing through the intersection when the bus approaches the intersection using an optical beacon has already been performed. However, this signal control is a control for securing a regular operation of a bus that is a public transport, and is intended for a vehicle equipped with an in-vehicle device for an optical beacon.

  An object of the present invention is to provide a signal control device that prevents a traffic flow rate at an intersection from being lowered by suppressing a leading vehicle waiting for a signal at an intersection from becoming a large vehicle.

  In order to achieve the above object, the signal control device of the present invention is configured as follows.

  In this signal control device, the traveling speed estimation means estimates the traveling speed of the vehicle on the link based on the vehicle sensing signal of a sensor that senses the presence of the vehicle at the sensing position on the intersection link. In addition, the vehicle type determination means calculates the vehicle length of the vehicle that has passed the sensing position using the estimated traveling speed, and determines whether or not the vehicle is a large vehicle. Further, the arrival time calculation means calculates the arrival time at which the vehicle determined to be a large vehicle reaches the intersection using the estimated traveling speed.

  Then, based on the arrival time of the intersection calculated for the large vehicle, the leading vehicle determination means determines whether or not the leading vehicle waiting for a signal at the intersection is a large vehicle. When the leading vehicle becomes a large vehicle, the display extension means extends the display of the large vehicle according to the arrival time when the large vehicle reaches the intersection, and passes the intersection at the display of the current cycle. Thereby, it can suppress that a large vehicle becomes a signal waiting top vehicle in an intersection, and the fall of the traffic flow rate in an intersection can be prevented.

  The traveling speed of the vehicle on the link may be estimated, for example, by measuring the occupancy rate of the vehicle at the sensing position and the number of passing vehicles. Also, for each cycle of the traffic light, the vehicle occupancy at the sensing position and the number of passing vehicles are measured in each time zone divided at regular time intervals based on the start timing, and the vehicle occupancy in each time zone, and The number of passing vehicles may be calculated statistically, and the traveling speed of the vehicle on the link may be estimated for each time zone.

  Further, it is estimated whether the vehicle that reaches the intersection near the end time of the current cycle indication passes the sensing position, and only the vehicle that has passed the sensing position at the estimated passing timing is a large vehicle. You may make it determine whether.

  According to this invention, it is possible to suppress a large vehicle from becoming a leading vehicle waiting for a signal at an intersection, and to prevent a decrease in traffic flow rate at the intersection.

It is the schematic which shows the road network to which the signal control apparatus which is embodiment of this invention was applied. It is a figure which shows the structure of the principal part of a signal control apparatus. It is a flowchart which shows operation | movement of a signal control apparatus. It is a figure which shows a vehicle detection signal. It is a figure explaining a cyclic flow profile.

  Hereinafter, a signal control apparatus according to an embodiment of the present invention will be described.

  First, a road network to which a signal control device according to an embodiment of the present invention is applied will be described. FIG. 1 is a schematic diagram showing a road network to which a signal control apparatus according to an embodiment of the present invention is applied. At the intersection, a traffic light 10 (only one is shown in the figure) is installed for each traveling direction of the vehicle. The signal control device 1 controls the display display of each traffic light 10 installed at this intersection. In addition, a sensor 11 for detecting the passage of the vehicle is provided at the inflow link at the intersection. The sensor 11 inputs a vehicle detection signal indicating whether or not a vehicle is present at the detection position (the presence or absence of a vehicle) to the connected signal control device 1. As the sensor 11, a metal sensitive type (loop type, magnetic type, etc.), a solid sensitive type (ultrasonic type, radar type, etc.), etc. are known.

  FIG. 2 is a diagram illustrating a configuration of a main part of the signal control device. The signal control device 1 includes a control unit 2, a sensing signal input unit 3, a display control unit 4, a storage unit 5, and a communication unit 6. As described above, the signal control device 1 controls the display of each traffic signal 10 installed at the intersection. Here, the presenting of the vehicle group traveling on the inflow link shown in FIG. 1 is referred to as the main presenting, and the presenting of the intersecting vehicle group is referred to as the intersecting presenting. The control unit 2 controls the operation of each part of the main body of the signal control device 1.

  The sensing signal input unit 3 receives a vehicle sensing signal from the connected sensor 11. The vehicle detection signal is a signal indicating the presence or absence of a vehicle at the detection position. The signal control device 1 can obtain the number of vehicles that have passed through the sensing position, etc., based on the vehicle sensing signal. The display control unit 4 controls the display display of each traffic signal 10 installed at the intersection. The storage unit 5 stores signal control parameters used for displaying the current signal 10 and various data used during operation. The communication unit 6 performs data communication with a traffic control center (not shown).

  When a large vehicle such as a truck or bus is at the head of a signal waiting stop vehicle at an intersection, the signal control device 1 reduces the traffic flow rate at the intersection, so that the signal waiting leading vehicle at the intersection becomes a large vehicle. The display display of the traffic light 10 which suppresses becoming is controlled. The decrease in the traffic flow rate at the intersection is a major factor causing traffic jams. Therefore, the occurrence of traffic jams can be suppressed by suppressing the leading vehicle waiting for traffic lights at the intersection from becoming a large vehicle.

  In addition, when the leading vehicle waiting for a signal at the intersection becomes a large vehicle, the cause of the decrease in the traffic flow rate at the intersection is that the large vehicle has poor acceleration performance at the time of starting compared to a general vehicle (the acceleration is small). ) That is, when the leading vehicle waiting for a signal at the intersection is a large vehicle, the speed when the large vehicle passes through the intersection is relatively low.

  The signal control device 1 determines whether or not a large vehicle that has passed the sensing position of the sensor 11 becomes a signal-waiting leading vehicle at an intersection, and if it is determined that it becomes the leading vehicle, the main indication of the current cycle And let this large vehicle pass without stopping at the intersection. That is, it is possible to prevent the leading vehicle waiting for a signal at an intersection from becoming a large vehicle. This suppresses a decrease in traffic flow rate at the intersection.

  Hereinafter, the operation of the signal control apparatus 1 will be described in detail.

  FIG. 3 is a flowchart showing the operation of this signal control apparatus. The signal control device 1 controls the display of each traffic signal 10 installed at the intersection based on the set signal control parameters. The signal control apparatus 1 sets the average speed of the vehicle in the inflow link of the intersection shown in FIG. 1 at the start of the cycle of the traffic light 10 (s1). The average speed set here is estimated in the previous cycle. The process for estimating the average speed will be described later.

Each time the vehicle passes through the sensing position, the signal control device 1 determines whether the vehicle is a large vehicle such as a truck or a bus (s2, s3). As shown in FIG. 4, the vehicle detection signal indicates the presence of the vehicle while the vehicle passes the detection position. That is, the period in which the vehicle detection signal indicates the presence of the vehicle continuously in time indicates the passage of one vehicle, and the length of this period is proportional to the length of the vehicle that has passed. The signal control device 1 detects a vehicle detection signal input to the detection signal input unit 3 every 50 msec, for example, and measures a period during which the vehicle is present continuously and its length. (Count the number of detection pulses.) The signal control device 1 calculates the vehicle length of the vehicle that has passed the current sensing position, using the counted number of detected pulses and the average speed set in s1. The commander
Vehicle length = (number of detected pulses counted this time) x (pulse interval [sec]) x (average vehicle speed [m / sec])
Can be calculated.

If the vehicle length calculated here is a predetermined length, for example, 8 m or more, the signal control device 1 determines that the vehicle is a large vehicle. When the signal control device 1 determines that the vehicle is a large vehicle in s3, the signal control device 1 calculates an estimated arrival time when the large vehicle reaches the intersection (s4). This estimated arrival time is
Estimated arrival time = (Vehicle sensing time at the sensing position)
+ (Distance between sensing position and intersection stop line [m]) / (Average speed of vehicle [m / sec])
Can be calculated.

  Based on the end time of the main display of the current cycle and the predicted arrival time calculated in s4, the signal control device 1 determines whether the large vehicle detected this time is the leading vehicle waiting for signals at the intersection. (S5). In s5, if the predicted arrival time calculated in s4 is later than the end time of the main display of the current cycle and the time difference is within a predetermined time (for example, within 2 to 5 seconds), at the intersection It is determined that the vehicle is the leading vehicle waiting for a signal.

  If the signal control device 1 determines that the large vehicle detected this time at s5 is the leading vehicle waiting for the signal at the intersection, it performs an extension process to delay the end timing of the main display in the current cycle (s6). In s6, an extension process is performed in which the end time of the main display in the current cycle is set to the predicted arrival time calculated in s4 or a time delayed by about 1 second from the predicted arrival time.

  Thereby, the large vehicle determined to be the leading vehicle waiting for a signal at the intersection can pass through the intersection without stopping. That is, it is possible to suppress a large vehicle from becoming a leading vehicle waiting for a signal at an intersection.

  In the above-described processing, when the main display time is extended in order to pass the large processing, it is preferable to shorten the time of the next cycle by this extended time and maintain the offset with the surrounding intersection. . In this case, the main display time of the next cycle may be shortened by the extended time, or the split may be maintained to shorten the time extended by the main display and the crossing side display.

  Next, a process for estimating the average speed of the vehicle set in s1 will be described. Here, the average speed of the vehicle in the inflow link is estimated from the traffic flow rate at the sensing position of the sensor 11. The signal control device 1 measures the traffic flow rate at the sensing position of the sensor 11 for each cycle of the traffic light 10. The number of vehicles passing at the sensing position of the sensor 11 can be measured by the vehicle sensing signal of the sensor 11.

  Further, the signal control device 1 measures the traffic flow rate at the sensing position of the sensor 11 during a period when the speed of the vehicle traveling on the inflow link at the intersection is stable. That is, in the same way as the measurement of the occupancy rate described above, the vehicle group in the inflow link at this intersection is stopped waiting for a signal, the acceleration period when the start is started from the stop state, and further for stopping from the running state. The vehicle detection signal during the deceleration period is not used. What is necessary is just to set the period which does not use this vehicle detection signal on the basis of the start timing of the main display in the traffic light 10. FIG.

The signal control device 1 counts the number of vehicles that have passed the sensing position of the sensor 11 and the number of detection pulses during the period in which the presence of the vehicle was detected during the measurement period. The signal control device 1 calculates the average speed of the vehicle using the number measured here and the number of pulses in the period during which the presence of the vehicle was detected. In particular,
Average vehicle speed = (average vehicle length) / ((pulse interval) x (total number of detected pulses) / (number of vehicles passed))
Calculated by

  In general roads, the mixing rate of large vehicles is at most about 30%, and most are ordinary vehicles such as private cars. From this, the average vehicle length of the vehicle that has passed the sensing position of the sensor 11 may be set to about 6 m.

  The signal control device 1 sets the average speed of the vehicle to the value estimated in the previous cycle in s1 described above. Moreover, it is good also as a structure which sets the average speed of the vehicle estimated by the last 10 cycles or 5 cycles.

  In this case, as in the case where the average speed of the vehicle is estimated from the above-described occupancy rate, signal control can be performed for a large vehicle such as a truck that does not have an onboard device for optical beacons. In addition, since the time when a large vehicle reaches the intersection can be predicted according to the traffic situation at this inflow link, the time from when the detected large vehicle passes the intersection until the main display of the current cycle is completed Can be prevented from becoming unnecessarily long.

  Moreover, the signal control apparatus 1 is good also as a structure which produces the cyclic flow profile and estimates the average speed of the vehicle in the inflow link of an intersection. The cyclic flow profile is obtained by measuring the traffic flow rate at regular time intervals (for example, every 5 seconds) based on the cycle start timing of the traffic light 10 and statistically processing the traffic flow rate. For example, as shown in FIG. 6, the number of vehicles that have passed the sensing position and the number of detection pulses are counted at regular time intervals based on the cycle start timing of the traffic light 10. The number of vehicles that have passed through the sensing position and the number of detected pulses are set to values statistically processed based on the above measurement results at regular intervals based on the cycle start timing of the traffic light 10. is there. For example, the number of vehicles that have passed the sensing position and the number of detection pulses are set to the average value of the past 10 cycles at regular intervals based on the cycle start timing of the traffic light 10. In addition, the number of vehicles that have passed the sensing position and the number of detection pulses may be obtained at regular intervals based on the cycle start timing of the traffic light 10 by the exponential smoothing method described below.

In exponential smoothing,
Number of vehicles passing through = Number of vehicles passing this time × α + Current number of vehicles × (1−α)
Number of detected pulses = current number of detected pulses × β + number of detected pulses measured this time × (1−β)
β = α × (Number of vehicles measured this time) / (Current number of vehicles)
Thus, the number of vehicles that have passed the sensing position and the number of detection pulses are calculated.

  Α is a smoothing coefficient, and 0 <α <1. α is, for example, 0.2. Β is a smoothing coefficient considering the weight of the number of units to be measured.

  As is apparent from the above description, in this cyclic flow profile, the average speed of the vehicle can be obtained at regular time intervals based on the cycle start timing of the traffic light 10. Further, immediately after passing through the sensing position of the sensor 11, the average speed of the vehicle that has passed can be obtained. Therefore, the calculation accuracy of the predicted arrival time when this vehicle reaches the intersection can be further improved.

  In the above description, the vehicle length is calculated for all vehicles that have passed the sensing position, and it is estimated whether or not the vehicle is a large vehicle. Since the end time of the main display in the cycle is obtained first, the vehicle length is calculated only for the vehicle that is determined to be the leading vehicle waiting for the signal at the intersection, and it is determined whether it is a large vehicle. May be. In other words, a vehicle that does not become a leading vehicle waiting for a signal at an intersection may be configured not to determine whether it is a large vehicle.

1-signal control device 2-control unit 3-sensing signal input unit 4-display control unit 5-storage unit 10-signal device 11-sensor

Claims (3)

In the signal control device that controls the display indication of the traffic light installed at the intersection based on the set signal control parameter,
A traveling speed estimating means for estimating a traveling speed of the vehicle on the link based on a vehicle sensing signal of a sensor that senses the presence of the vehicle at a sensing position on the intersection link;
Vehicle type determination means for calculating the vehicle length of the vehicle that has passed the sensing position using the travel speed estimated by the travel speed estimation means, and determining whether the vehicle is a large vehicle;
An arrival time calculating means for calculating an arrival time at which the vehicle determined to be a large vehicle by the vehicle type determining means reaches the intersection using the traveling speed estimated by the traveling speed estimating means;
Based on the arrival time of the intersection calculated by the arrival time calculation means for the large vehicle, leading vehicle determination means for determining whether or not the leading vehicle waiting for a signal at the intersection is the large vehicle;
When the leading vehicle determination means determines that the leading vehicle waiting for a signal at the intersection is a large vehicle, the display extension is performed to extend the display of the large vehicle according to the arrival time when the large vehicle reaches the intersection. And a signal control device.   The travel speed estimation means measures the occupancy rate of the vehicle at the sensing position and the number of passing vehicles in each time zone divided at regular time intervals based on the start timing for each cycle of the traffic light. The signal control device according to claim 1, which is a means for statistically calculating a vehicle occupancy rate and the number of vehicles passing through the vehicle and estimating a traveling speed of the vehicle on the link for each time zone.   Whether the vehicle type determination means is a large vehicle with respect to a vehicle that reaches the intersection near the end time of the current cycle according to the traveling speed of the vehicle on the link estimated by the traveling speed estimation means. The signal control apparatus according to claim 1, wherein the signal control apparatus is a means for determining a signal.

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