JP6394305B2 - Staying number measuring device, signal control system, staying number measuring method, and staying number measuring program - Google Patents

Description

  The present invention relates to a technique for estimating the number of vehicles staying on a link.

  Conventionally, in order to suppress the occurrence of traffic jams in the road network and to quickly eliminate the traffic jams that occur, traffic signals that flow out to the bottleneck intersections are signaled at the inflow links (so-called bottleneck intersections) where traffic jams are likely to occur. 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. An apparatus having a configuration for measuring the number of devices 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 technique described in Patent Document 1, an inflow path through which a vehicle flows into the inflow link and an outflow path through which the vehicle flows out from the inflow link are connected between the inlet and the outlet of the inflow link. The number of vehicles staying in the inflow link cannot be estimated accurately. That is, the number of vehicles measured by the technique described in Patent Document 1 is the difference between the number of vehicles that have flowed into the inflow link from the inflow channel and the number of vehicles that have flowed out of the inflow link to the outflow channel. Include as.

  In the following description, the inflow path and the outflow path may be collectively referred to as a branch path. The branch road includes not only a road that functions as one of an inflow path or an outflow path but also a road that functions as an inflow path and an outflow path. Further, the branch road may be an intersection where a signal lamp is installed, or may be an intersection where no signal lamp is installed.

  In addition, if a vehicle detector is installed in each branch path and the number of vehicles flowing into the inflow link in each branch path and the number of vehicles flowing out from the inflow link are detected, the vehicle stays in the inflow link. The number of vehicles can be accurately measured. However, when installing a vehicle detector on each branch road, it is necessary to increase the number of cables to be laid and increase the number of communication lines, which greatly increases the cost for system construction, operation, maintenance and the like.

  If the number of vehicles staying in the inflow link cannot be estimated with high accuracy, proper signal control cannot be performed even if the technique described in Patent Document 2 is used.

  An object of the present invention is to provide a technique capable of accurately estimating the number of vehicles staying in an inflow link while suppressing an increase in cost for system construction, operation, maintenance and the like.

  In order to achieve the above object, the staying number measuring apparatus of the present invention is configured as follows.

This staying number measuring device estimates the number of vehicles staying in a link where at least one of an inflow path through which a vehicle flows in or an outflow path through which the vehicle flows out is connected between an entrance and an exit. The inflow number acquisition unit acquires the number of vehicles flowing into the link (inflow number Q1) at the entrance of the link. In addition, the outflow number acquisition unit acquires the number of vehicles that have flowed out from the link (outflow number Q2) at the exit of the link. For example, the inflow number acquisition unit may be configured to process a captured image obtained by imaging the entrance of the link and acquire the inflow number Q1 of the vehicle that has flowed into the link. In addition, the inflow number acquisition unit flows into this link by detecting the vehicle with a loop coil type vehicle detection sensor embedded at the entrance of the link or an ultrasonic type vehicle detection sensor provided at the entrance of the link. The structure which acquires the inflow number Q1 of a vehicle may be sufficient. Moreover, the structure which acquires the outflow number Q2 of the vehicle which flowed from the link, for example, processes the picked-up image which imaged the exit of the link, and the outflow number acquisition part may be sufficient as it. In addition, the outflow number acquisition unit leaked from this link by detecting the vehicle with a loop coil type vehicle detection sensor embedded at the exit of the link or an ultrasonic type vehicle detection sensor provided at the exit of the link. The structure which acquires the outflow number Q2 of a vehicle may be sufficient.

If the inflow path through which the vehicle flows into the link and the outflow path through which the vehicle flows out from the link are not connected between the entrance and the exit of the link, the number of vehicles staying in the link (the number of stays Q) is ,
Q = (Q1-Q2) + previous number of stays. On the other hand, if at least one of the inflow path through which the vehicle flows into the link or the outflow path through which the vehicle flows out from the link is connected between the entrance and the exit of the link, the number of vehicles staying at the link Q is
Q = (Q1-Q2) + (Q3-Q4) + the previous number of stays.
However, Q3 is the number of vehicles flowing into the link from the inflow path, and Q4 is the number of vehicles flowing out from the link to the outflow path.

The entrance side saturation level acquisition unit acquires the saturation level (DS: Degree of Saturation) of the link entrance. In general, the saturation DS at the entrance of the link increases as the number of vehicles staying at the link increases. The saturation DS is obtained, for example, by using the number Q1 of vehicle inflows at the link entrance and the representative value V of the speed of these vehicles, the number Q1 of vehicle inflows at the link entrance, and the link entrance. There is a method of acquiring using the inter-vehicle time T when the vehicle is not located.

  The vehicle speed representative value V and the inter-vehicle time T can be acquired by processing a captured image obtained by imaging the entrance of the link. The inter-vehicle time T can also be obtained by processing a vehicle detection signal by a loop coil type vehicle detection sensor embedded at the entrance of the link.

The vehicle number estimation unit is acquired by the inflow unit Q1 of the vehicle that has flowed into the link acquired by the inflow unit acquisition unit, the outflow number Q2 of the vehicle that has flowed out of the link acquired by the outflow unit acquisition unit, and the entrance-side saturation acquisition unit The staying number Q of vehicles staying on the link is estimated using the saturation DS at the entrance of the link.

  As described above, the saturation DS at the entrance of the link increases as the number Q of vehicles staying in the link increases. Since the vehicle number estimation unit uses the saturation DS at the entrance of the link to estimate the number Q of vehicles staying in the link, the number of vehicles flowing into the link (Q3) and It is possible to accurately estimate the staying number Q of vehicles staying on the link without acquiring the number (Q4) of vehicles flowing into the outflow path. That is, according to this configuration, it is possible to accurately estimate the number of vehicles staying on the link while suppressing an increase in cost for system construction, operation, maintenance and the like.

The vehicle number estimation unit uses the saturation DS at the entrance of the link acquired by the saturation acquisition unit as a parameter for correcting the inflow number Q1 of vehicles that have flowed into the link acquired by the inflow number acquisition unit, and stays in the link. The remaining number Q of vehicles
Q = (Q1 × f (DS) −Q2) + the number of stays calculated previously may be calculated. However, f (DS) is a function using the saturation DS at the entrance of the link acquired by the saturation acquisition unit as a variable, and the value increases as DS increases.

In addition, the vehicle number estimation unit uses the saturation DS at the entrance of the link acquired by the saturation acquisition unit as a parameter for correcting the outflow number Q2 of vehicles that have flowed out of the link acquired by the outflow number acquisition unit, and The remaining number Q of vehicles that are staying
You may calculate by Q = Q1-Q2 * g (DS) + last-stayed residence number. However, g (DS) is a function using the saturation DS at the entrance of the link acquired by the saturation acquisition unit as a variable, and the value decreases as DS increases.

Further, the vehicle number estimation unit calculates the difference (Q1-Q2) between the inflow number Q1 of vehicles that have flowed into the link acquired by the inflow number acquisition unit and the outflow number Q2 of vehicles that have flowed out of the link acquired by the outflow number acquisition unit. Used as a parameter to be corrected, the staying number Q of vehicles staying at the link is
Q = (Q1−Q2) × q (DS) + the number of stays calculated previously may be calculated. However, q (DS) is a function using the saturation DS at the entrance of the link acquired by the saturation acquisition unit as a variable, and the value increases as DS increases.

  The functions f (DS), g (DS), and q (DS) described above may be determined according to the traffic environment on the link. In addition, the functions f (DS), g (DS), and q (DS) may be linear functions, quadratic functions, or tertiary or higher functions.

In addition, a signal control parameter for controlling the display display of the signal lamp that restricts the traveling of the vehicle flowing out from the exit of the link is generated using the number of vehicles staying on the link estimated by the vehicle number estimating unit . Therefore, it is possible to appropriately suppress the occurrence of traffic congestion on the link and to quickly eliminate the traffic congestion generated on the link.

  According to the present invention, an increase in the cost for system construction, operation, maintenance and the like can be suppressed, and the number of vehicles staying in the inflow link can be estimated with high accuracy.

It is the schematic which shows the signal control system concerning this example. It is a block diagram which shows the structure of the principal part of a traffic control center. FIG. 3A is a block diagram showing the configuration of the main part of the outflow side image sensor, and FIG. 3B is a block diagram showing the configuration of the main part of the inflow side image sensor. FIG. 4A is a diagram illustrating a functional configuration of an image processing processor included in the outflow side image sensor, and FIG. 4B is a diagram illustrating a functional configuration of the image processing processor included in the inflow side image sensor. It is a figure explaining a QV plot. It is a flowchart which shows operation | movement of an inflow side image sensor. It is a flowchart which shows operation | movement of an outflow side image sensor. It is a block diagram which shows the structure of the principal part of the image sensor concerning another example. It is the schematic which shows the signal control system concerning another example.

  Hereinafter, a signal control system according to an embodiment of the present invention will be described. This signal control system has a staying number measuring apparatus according to an embodiment of the present invention.

FIG. 1 is a schematic diagram showing a signal control system according to this example. Here, the number of vehicles staying at the inflow link of the intersection A is estimated, and the signal control parameter (signal control device) for controlling the display of the signal lamp 5a installed at the intersection A according to the estimation result A case where the signal control parameter 3a) is generated will be described as an example.

  The inflow link of the intersection A here is a road located between the intersection A and the intersection B shown in FIG. 1 and the vehicle travels from the intersection B side to the intersection A side. The inflow link at intersection A is upstream on the intersection B side and downstream on the intersection A side.

  In practice, the inflow link connected to the intersection A is not limited to the link located between the intersection A and the intersection B.

  As shown in FIG. 1, the inflow link at the intersection A is connected to a branch path through which the vehicle flows into the inflow link or the vehicle flows out of the inflow link. The number of branch paths connected to the inflow link at the intersection A is not limited to the two shown in FIG. Further, the branch path connected to the inflow link at the intersection A may be a branch path (inflow path) where the vehicle can only flow into the inflow link at the intersection A (cannot flow out), or the vehicle may flow into the intersection A. It may be a branch path (outflow path) that can only flow out (cannot flow in) from the link.

  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. As will be described later, the signal control device 3a controls the display indication of the plurality of signal lamps 5a installed at the intersection A based on the signal control parameter notified from the traffic control center 1, and the outflow side image sensor. 2a is notified in real time of the intersection A. Based on the signal control parameter notified from the traffic control center 1, the signal control device 3b controls the display indication of the plurality of signal lamps 5b installed at the intersection B, and the inflow side image sensor 2b Notify the real time in real time.

  The outflow side image sensor 2a acquires the number of vehicles flowing out to the intersection A from the exit of the inflow link at the intersection A (end portion on the intersection A side) (hereinafter referred to as the outflow number Q2). In addition, the outflow side image sensor 2a acquires the degree of saturation at the exit of the inflow link at the intersection A (hereinafter referred to as saturation degree DS2).

  In general, the saturation degree DS is a value indicating the degree of congestion (congestion). When the degree of saturation DS> 1, it is a supersaturated state where traffic congestion has occurred. On the contrary, when the degree of saturation DS <1, it is a non-saturated state where no traffic jam occurs. Furthermore, the outflow side image sensor 2a estimates the number of vehicles staying on the inflow link of the intersection A (hereinafter referred to as staying number Q). Details of the outflow side image sensor 2a will be described later.

  The inflow side image sensor 2b acquires the number of vehicles flowing into the inflow link at the intersection A (hereinafter referred to as the inflow number Q1) from the entrance of the inflow link at the intersection A (end on the side of the intersection B). The inflow side image sensor 2b acquires the saturation level of the entrance of the inflow link at the intersection A (hereinafter referred to as the saturation level DS1).

  The traffic control center 1 generates a signal control parameter for controlling the display of the signal lamp 5a installed at the intersection A based on the staying number Q estimated by the outflow side image sensor 2a.

  The traffic control center 1 also generates a signal control parameter for controlling the display indication of the signal lamp installed at an intersection other than the intersection A (for example, the intersection B). The traffic control center 1 generates a signal control parameter for controlling the display indication of the signal lamp installed at each intersection based on the number of vehicles staying at the inflow link at the intersection.

  The traffic control center 1 is connected to the outflow side image sensor 2a, the inflow side image sensor 2b, and the signal control devices 3a and 3b by wire or wirelessly. The outflow side image sensor 2a and the inflow side image sensor 2b are connected by wire or wirelessly. The outflow side image sensor 2a and the signal control device 3a are connected by wire or wirelessly. Furthermore, the inflow side image sensor 2b and the signal control device 3b are connected by wire or wirelessly.

  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 signal control parameter generation unit 12, and an input / output unit 13.

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

  The signal control parameter generation unit 12 generates a signal control parameter for controlling the display indication of the signal lamp installed at each intersection. The signal control parameter generation unit 12 determines a signal control parameter for controlling the display indication of the signal lamp 5a installed at the intersection A based on the staying number Q of the inflow links at the intersection A estimated by the outflow side image sensor 2a. Generate.

  The input / output unit 13 performs communication related to data input / output among the outflow side image sensor 2a, the inflow side image sensor 2b, and the signal control devices 3a and 3b.

  FIG. 3A is a block diagram showing the configuration of the main part of the outflow side image sensor, and FIG. 3B is a block diagram showing the configuration of the main part of the inflow side image sensor. The outflow side image sensor 2a includes a control unit 21a, an image input unit 22a, an image processing processor 23a, and an input / output unit 24a. The inflow side image sensor 2b includes a control unit 21b, an image input unit 22b, an image processing processor 23b, and an input / output unit 24b. The outflow side image sensor 2a and the inflow side image sensor 2b have the same hardware configuration as shown in FIG. The outflow side image sensor 2a and the inflow side image sensor 2b correspond to the staying number measuring device referred to in the present invention.

  First, the configuration of the outflow side image sensor 2a will be described. The control unit 21a controls the operation of the main body of the outflow side image sensor 2a. Further, the control unit 21a estimates the staying number Q of the inflow links at the intersection A. In addition, the control unit 21a includes a memory that temporarily stores data generated during operation.

  The image input unit 22a receives a moving image captured by the video camera 20a. The imaging area of the video camera 20a is the exit of the inflow link at the intersection A shown in FIG. The frame rate of the video camera 20a is, for example, 30 frames / second. The image input unit 22a includes a storage unit such as an image memory that temporarily stores a moving image input from the video camera 20a (moving image obtained by capturing the exit of the inflow link at the intersection A).

  The image processor 23a processes the moving image input from the video camera 20a, obtains the number Q2 of outflows at the exit of the inflow link of the intersection A, and the representative value V2 of the speed of the vehicle that has flowed out. The saturation DS2 at the exit of the inflow link at the intersection A (imaging area of the video camera 20a) is acquired. A method for obtaining the saturation DS2 will be described later.

  The input / output unit 24a performs communication related to data input / output with the traffic control center 1, the inflow side image sensor 2b, the signal control device 3a, and the like.

  Next, the configuration of the inflow side image sensor 2b will be described. The control unit 21b controls the operation of the inflow side image sensor 2b main body. The control unit 21b includes a memory that temporarily stores data generated during operation.

  The image input unit 22b receives a moving image captured by the video camera 20b. The imaging area of the video camera 20b is the entrance of the inflow link at the intersection A shown in FIG. The frame rate of the video camera 20b is, for example, 30 frames / second. The image input unit 22b includes a storage unit such as an image memory that temporarily stores a moving image input from the video camera 20b (moving image obtained by capturing the entrance of the inflow link at the intersection A).

  The image processor 23b processes the moving image input from the video camera 20b, obtains the number Q1 of inflows at the entrance of the inflow link of the intersection A, and the representative value V1 of the speed of the inflowing vehicle, The saturation DS1 at the entrance of the inflow link at the intersection A (the imaging area of the video camera 20b) is acquired. A method for obtaining the saturation DS1 will be described later.

  The input / output unit 24b performs communication related to data input / output with the traffic control center 1, the outflow side image sensor 2a, the signal control device 3b, and the like.

  FIG. 4A is a diagram illustrating a functional configuration of an image processing processor included in the outflow side image sensor, and FIG. 4B is a diagram illustrating a functional configuration of the image processing processor included in the inflow side image sensor.

  The image processor 23a includes a vehicle tracking unit 231a, a passing number acquisition unit 232a, a vehicle speed acquisition unit 233a, and a DS acquisition unit 234a. Similarly, the image processor 23b includes a vehicle tracking unit 231b, a passing number acquisition unit 232b, a vehicle speed acquisition unit 233b, and a DS acquisition unit 234b.

  First, the functional configuration of the image processor 23a will be described. The vehicle tracking unit 231a processes, for each cycle of the signal lamp 5a, a moving image of the inflow link exit at the intersection A captured by the video camera 20a when the current display is a vehicle group of the inflow link at the intersection A, The vehicle that has flowed out from the exit of the inflow link at intersection A is tracked. As described above, since the signal control device 3a notifies the outflow side image sensor 2a of the indication of the intersection A in real time, the outflow side image sensor 2a can determine the indication of the intersection A in real time. The tracking of the vehicle is performed by processing the frame image captured by the video camera 20a in time series to detect the captured vehicle, and the vehicle ID, detection time (frame image capturing time), and position (on the intersection). This can be done by generating an object map that associates coordinates indicating the position. Since a technique for processing a captured image of the video camera 20a and tracking an imaged object (here, a vehicle) is well known, a detailed description thereof will be omitted.

  Note that the vehicle tracking unit 231a may always process a moving image of the exit of the inflow link of the intersection A captured by the video camera 20a and track the vehicle that has flowed out of the inflow link of the intersection A. However, when the current display is not the vehicle group of the inflow link at the intersection A, the vehicle does not flow out from the exit of the inflow link at the intersection A. Therefore, as described above, the vehicle tracking unit 231a processes the moving image at the exit of the inflow link of the intersection A captured by the video camera 20a when the current display is the vehicle group of the inflow link of the intersection A. By adopting a configuration for tracking the vehicle that has flowed out from the exit of the inflow link of A, it is possible to suppress an unnecessary increase in processing load.

  The passing number acquisition unit 232a acquires the number Q2 of outflows at the exit of the inflow link at the intersection A for each cycle of the signal lamp 5a. The passing number acquisition unit 232a acquires the outflow number Q2 using the object map generated in the vehicle tracking unit 231a. The movement trajectory of each vehicle is obtained from the object map.

  The vehicle speed acquisition unit 233a calculates a representative value V2 of the speed of the vehicle that has flowed out from the exit of the inflow link at the intersection A for each cycle of the signal lamp 5a. The representative value V2 may be an average value of the speed of the vehicle that has flowed out from the exit of the inflow link at the intersection A, or may be a median value. The speed of each vehicle is obtained by dividing the moving distance of the vehicle by the time during which the vehicle tracking unit 231a was tracking the vehicle (moving distance / tracking time). The movement distance may be calculated from the movement trajectory of the vehicle obtained from the object map. However, since the vehicle does not meander at the exit of the inflow link of the intersection A, from the viewpoint of suppressing the processing load, the vehicle tracking unit It is preferable that the length in the traveling direction of the vehicle that 231a tracks the movement of the vehicle is determined in advance as the movement distance. The tracking time is a time difference between the imaging time of the frame image in which the vehicle is first detected and the imaging time of the frame image in which the vehicle is last detected.

  The DS acquisition unit 234a acquires the saturation DS2 at the exit of the inflow link at the intersection A for each cycle of the signal lamp. The DS acquisition unit 234a uses the outflow number Q2 acquired by the passing number acquisition unit 232a and the representative value V2 of the vehicle speed acquired by the vehicle speed acquisition unit 233a, and the saturation DS2 at the exit of the inflow link at the intersection A. The outflow side DS function for calculating is stored.

  In a general link, when the present indication is a vehicle group of the link, there is a relationship shown in FIG. 5 between the number of vehicles flowing out from the exit of the link and the representative value of the vehicle speed. This relationship is called a QV plot. At the time of non-saturation (at the time of non-congestion), the representative value of the vehicle speed increases as the number of outflows decreases. On the other hand, at the time of oversaturation (in a traffic jam), the representative value of the vehicle speed decreases as the number of outflows decreases.

  The QV plot shown in FIG. 5 varies depending on the road structure (uphill, downhill, etc.) and the surrounding environment (good visibility, etc.). That is, the QV plot is different for each link. In FIG. 5, the point where the DS of the link becomes DS = 1 is the point where the number of outflows reaches a peak.

  Further, the vehicle speed is higher than the vehicle speed at the point where DS = 1 when DS <1, and is slower than the vehicle speed at the point where DS = 1 when DS> 1. As shown in FIG. 5, as the vehicle speed increases, the link exit DS decreases, and as the vehicle speed decreases, the link exit DS increases. However, the DS value at the exit of the link does not change equally in the direction of the vertical axis (speed) in FIG.

  Thus, the outflow DS function can be determined based on the relationship between the link exit QV plot and the link exit DS.

  The DS acquisition unit 234a stores an outflow DS function determined based on the relationship between the QV plot at the exit of the inflow link at the intersection A and the DS2 at the exit of the inflow link at the intersection A.

  Next, the functional configuration of the image processor 23b will be described. The vehicle tracking unit 231b is configured to display the inflow link of the intersection A captured by the video camera 20b when the current display is a group of vehicles that travel straight through the intersection B and flow into the inflow link of the intersection A for each cycle of the signal lamp 5b. The moving image of the entrance is processed, and the vehicle that has entered from the entrance of the inflow link at the intersection A is tracked. As described above, since the signal control device 3b notifies the inflow side image sensor 2b of the present of the intersection B in real time, the inflow side image sensor 2b can determine the present of the intersection B in real time. The tracking of the vehicle is performed by processing the frame image captured by the video camera 20b in time series to detect the captured vehicle, and the vehicle ID, detection time (frame image capturing time), and position (on the intersection). This can be done by generating an object map that associates coordinates indicating the position.

  Note that the vehicle tracking unit 231b may always process a moving image of the entrance of the inflow link of the intersection A captured by the video camera 20b to track the vehicle that has flowed into the inflow link of the intersection A. However, when the current display is not a vehicle group that travels straight through the intersection B and flows into the inflow link of the intersection A, the vehicle does not travel straight through the intersection B and enter the inflow link of the intersection A. Therefore, as described above, the vehicle tracking unit 231b is the entrance of the inflow link of the intersection A imaged by the video camera 20b when the current display is a vehicle group that travels straight through the intersection B and flows into the inflow link of the intersection A. By processing the moving image and tracking the vehicle that has flowed into the inflow link at the intersection A, it is possible to prevent the processing load from increasing unnecessarily. Further, there are vehicles that turn right or left at the intersection B and flow into the inflow link of the intersection A, but these vehicles may be regarded as vehicles that flow from the branch road.

  The passing number acquisition unit 232b has a number of inflows Q1 at the entrance of the inflow link at the intersection A when the current indication is a vehicle group that travels straight through the intersection B and flows into the inflow link at the intersection A every cycle of the signal lamp 5b. To get. The passing number acquisition unit 232b acquires the inflowing number Q1 using the object map generated in the vehicle tracking unit 231b. The movement trajectory of each vehicle is obtained from the object map.

  The vehicle speed acquisition unit 233b calculates a representative value V1 of the speed of the vehicle that goes straight through the intersection B and flows into the inflow link of the intersection A for each cycle of the signal lamp 5b. The representative value V1 may be an average value of the vehicle speed at the entrance of the inflow link at the intersection A or a median value. The speed of each vehicle is obtained by dividing the moving distance of the vehicle by the time during which the vehicle tracking unit 231b was tracking the vehicle (moving distance / tracking time). The movement distance may be calculated from the movement trajectory of the vehicle obtained from the object map. However, since the vehicle does not meander at the entrance of the inflow link of the intersection A, the vehicle tracking unit is considered from the viewpoint of suppressing the processing load. It is preferable that the length in the traveling direction of the vehicle that 231b tracks the movement of the vehicle is determined in advance as the movement distance. The tracking time is a time difference between the imaging time of the frame image in which the vehicle is first detected and the imaging time of the frame image in which the vehicle is last detected.

  The DS acquisition unit 234b acquires the saturation DS1 at the entrance of the inflow link at the intersection A for each cycle of the signal lamp. The DS acquisition unit 234b uses the inflow number Q1 acquired by the passing number acquisition unit 232b and the representative value V1 of the vehicle speed acquired by the vehicle speed acquisition unit 233b, and the saturation DS1 of the entrance of the inflow link at the intersection A The inflow side DS function for calculating is stored.

  This inflow DS function is also a function determined based on the relationship between the QV plot at the entrance of the inflow link at intersection A and the DS at the entrance of the inflow link at intersection A, as with the above-described outflow DS function. .

  Hereinafter, a process of estimating the staying number Q that is the number of vehicles staying on the inflow link of the intersection A will be described. This process is performed by the outflow side image sensor 2a and the inflow side image sensor 2b.

  FIG. 6 is a flowchart showing the operation of the inflow side image sensor. FIG. 7 is a flowchart showing the operation of the outflow side image sensor.

  First, the operation of the inflow side image sensor 2b will be described with reference to FIG. The inflow side image sensor 2b receives the indication of the intersection B from the signal control device 3b. The inflow side image sensor 2b travels straight on the intersection B and reaches the start timing of the vehicle group flowing into the inflow link of the intersection A (hereinafter referred to as inflow vehicle detection start timing). Vehicle tracking processing at the entrance of the inflow link (hereinafter referred to as inflow vehicle tracking processing) is started (s1, s2). In the inflow vehicle tracking process relating to s2, the vehicle tracking unit 231b processes the inflow link entrance image of the intersection A imaged by the video camera 20b after the inflow vehicle detection start timing, and passes through the inflow link entrance of the intersection A. Is a process of tracking. The inflow-side image sensor 2b travels straight at the intersection B and enters the inflow vehicle tracking process started at s2 when the display end timing of the vehicle group flowing into the inflow link at the intersection A (hereinafter referred to as inflow vehicle detection end timing) is reached. Is finished (s3, s4).

  In s1 to s4, the vehicle tracking unit 231b processes the inflow link entrance image of the intersection A captured by the video camera 20b between the inflow vehicle detection start timing and the inflow vehicle detection end timing. Create an object map of the vehicle that has passed the link entrance.

  The inflow side image sensor 2b acquires the inflow number Q1 at the entrance of the inflow link of the intersection A based on the object map created by the inflow vehicle tracking process executed by the vehicle tracking unit 231b in the passing number acquisition unit 232b (s5). In s5, the number of vehicles that have passed through the entrance of the inflow link at the intersection A between s1 and s4 is acquired as the inflow number Q1.

  Further, the inflow side image sensor 2b obtains a representative value V1 of the speed of the vehicle that has flowed into the inflow link at the intersection A based on the object map created by the inflow vehicle tracking process executed by the vehicle tracking unit 231b in the vehicle speed acquisition unit 233b. Obtain (s6). The representative value V1 of the vehicle speed may be an average value or a median value of the speeds of the vehicles that have passed through the entrance of the inflow link at the intersection A. In s6, the representative value V1 of the speed of the vehicle that has passed through the entrance of the inflow link at the intersection A between s1 and s4 is acquired.

  The inflow side image sensor 2b acquires the saturation DS1 at the entrance of the inflow link at the intersection A in the DS acquisition unit 234b (s7). The DS acquisition unit 234b uses the inflow number Q1 acquired in s5 and the representative value V1 of the vehicle speed acquired in s6, and stores the saturation of the entrance of the inflow link at the intersection A by the stored inflow DS function. Get DS1.

  The inflow side image sensor 2b transmits the inflow number Q1 acquired in s5 and the saturation DS1 at the entrance of the inflow link of the intersection A acquired in s7 to the outflow side image sensor 2a (s8), and returns to s1.

  Next, the operation of the outflow side image sensor 2a will be described with reference to FIG. The outflow side image sensor 2a uses the input / output unit 24a to input the inflow quantity Q1 acquired in s5 transmitted by the inflow side image sensor 2b in s8 and the saturation DS1 of the inflow link at the intersection A acquired in s7 at the input / output unit 24a. When received, it is stored in a memory (not shown) provided in the control unit 21a.

  The outflow side image sensor 2a receives the indication of the intersection A from the signal control device 3a. When the flow-out side image sensor 2a reaches the display start timing of the vehicle group flowing out from the inflow link of the intersection A to the intersection A (hereinafter referred to as the outflow vehicle detection start timing), the vehicle tracking unit 231a Vehicle tracking processing at the exit (hereinafter referred to as outflow vehicle tracking processing) is started (s11, s12). In the spilled vehicle tracking process in s12, the vehicle tracking unit 231a processes the image of the inflow link exit of the intersection A captured by the video camera 20a after the start timing of the spilled vehicle detection, and passes through the inflow link exit of the intersection A. Is a process of tracking. The outflow side image sensor 2a ends the outflow vehicle tracking process started in s12 at the display end timing of the vehicle group flowing out from the inflow link of the intersection A (hereinafter referred to as outflow vehicle detection end timing) (s13, s14).

  In s11 to s14, the vehicle tracking unit 231a processes the inflow link exit image of the intersection A captured by the video camera 20a between the outflow vehicle detection start timing and the outflow vehicle detection end timing, and the inflow of the intersection A Create an object map of the vehicle that has passed the link exit.

  The outflow side image sensor 2a acquires the outflow number Q2 at the exit of the inflow link at the intersection A based on the object map created by the outflow vehicle tracking process executed by the vehicle tracking unit 231a in the passing number acquisition unit 232a (s15). In s15, the number of vehicles that have passed through the exit of the inflow link at the intersection A between s11 and s14 is acquired as the outflow number Q2.

  In addition, the outflow side image sensor 2a obtains a representative value V2 of the speed of the vehicle that has flowed out from the inflow link of the intersection A based on the object map created by the inflow vehicle tracking process executed by the vehicle tracking unit 231a in the vehicle speed acquisition unit 233a. Obtain (s16). The vehicle speed representative value V2 may be an average value or a median value of the speeds of the vehicles flowing out from the inflow link of the intersection A. In s16, the representative value V2 of the speed of the vehicle that has passed through the exit of the inflow link at the intersection A during s11 to s14 is acquired.

  The outflow side image sensor 2a acquires the saturation DS2 at the exit of the inflow link at the intersection A in the DS acquisition unit 234a (s17). The DS acquisition unit 234a uses the outflow number Q2 acquired in s15 and the representative value V2 of the vehicle speed acquired in s16 to store the saturation degree of the inflow link exit at the intersection A by the stored outflow DS function. Get DS2.

  The outflow side image sensor 2a stays in the inflow link of the intersection A if the saturation DS2 at the exit of the inflow link of the intersection A acquired in s17 is 1 or less (if it is not saturated) in the control unit 21a. The number Q of remaining vehicles is reset (Q = 0) (s18, s19).

On the other hand, the outflow side image sensor 2a stays in the inflow link at the intersection A unless the saturation degree DS2 at the exit of the inflow link at the intersection A acquired in s17 is 1 or less (if it is supersaturated) in the control unit 21a. The number Q of remaining vehicles is estimated (s18, s20). In s20, the inflow number Q1 transmitted from the inflow side image sensor 2b, the saturation DS1 at the entrance of the inflow link at the intersection A, the outflow number Q2 acquired in s15, and the staying number Q estimated in the previous cycle are used. ,
Number of stays Q = (Q1 × f (DS) −Q2) + Number of stays Q estimated in the previous cycle
Calculated by However, f (DS) is a function having the saturation DS1 at the entrance of the inflow link at the intersection A as a variable, and the value increases as DS1 increases. This f (DS) is a function for correcting the inflow number Q1.

  In general, the degree of saturation at the entrance of a link increases as the number of vehicles staying at the link increases. Therefore, the staying number Q of vehicles staying at the inflow link at the intersection A is connected to the inflow link at the intersection A by estimating using the saturation DS1 at the entrance of the inflow link at the intersection A. On the branch road, estimation can be performed in consideration of the number of vehicles that have flowed in and the number of vehicles that have flowed out. That is, it is possible to accurately estimate the staying number Q of vehicles staying in the inflow link of the intersection A without detecting the number of inflowing vehicles and the number of outflowing vehicles on each branch road. In addition, since it is not necessary to provide a configuration for detecting the number of vehicles that have flowed in and the number of vehicles that have flowed out in each branch road, it is possible to suppress an increase in costs for system construction, operation, maintenance, and the like.

Moreover, s20 is good also as a process which estimates the staying number Q using the function g (DS) which correct | amends the outflow number Q2. Specifically, the staying quantity Q is
Number of stays Q = (Q1−Q2 × g (DS)) + Number of stays Q estimated in the previous cycle
Calculated by However, g (DS) is a function having the saturation DS1 at the entrance of the inflow link at the intersection A as a variable, and the value decreases as DS1 increases.

Furthermore, s20 may be a process of estimating the staying number Q using a function q (DS) that corrects the difference between the inflowing number Q1 and the outflowing number Q2. Specifically, the staying quantity Q is
Number of stays Q = (Q1-Q2) × q (DS) + Number of stays Q estimated in the previous cycle
Calculated by However, q (DS) is a function having the saturation DS1 at the entrance of the inflow link at the intersection A as a variable, and the value decreases as DS1 increases.

  The functions f (DS), g (DS), and q (DS) described above are determined according to the traffic environment at the inflow link at the intersection A. In addition, the functions f (DS), g (DS), and q (DS) may be linear functions, quadratic functions, or tertiary or higher functions.

  The outflow side image sensor 2a calculates the saturation DS2 at the exit of the inflow link at the intersection A acquired in s17 and the staying quantity Q of the vehicles staying in the inflow link of the intersection A estimated in s18 or s20. 1 (s21), and returns to s11.

  In this way, in this example, the number of vehicles staying in the link is accurately estimated without detecting the number of vehicles that have flowed in and the number of vehicles that have flowed out in the branch path connected to the link. As a result, an increase in costs for system construction, operation, maintenance and the like can be suppressed.

  The traffic control center 1 uses the saturation DS2 at the exit of the inflow link at the intersection A and the staying number Q of vehicles staying at the inflow link at the intersection A, which are transmitted from the outflow side image sensor 2a. The signal control parameter (signal control parameter of the signal control device 3a) for controlling the display display of the signal lamp 5a installed in is generated. For example, the traffic control center 1 stores signal control parameters in advance for each pattern divided by the number of vehicles staying on the inflow link of the intersection A. The traffic control center 1 selects a signal control parameter corresponding to the number Q of vehicles staying in the inflow link of the intersection A, transmitted from the outflow side image sensor 2a, from the stored signal control parameters. The signal control parameter for controlling the display display of the signal lamp 5a installed at the intersection A is selected. The traffic control center 1 transmits the selected signal control parameter to the signal control device 3a.

  The signal control device 3a controls the display of the signal lamp 5a in the next cycle based on the signal control parameter transmitted from the traffic control center 1.

  Thereby, when the traffic jam has occurred in the inflow link of the intersection A, the traffic jam can be quickly eliminated.

  The traffic control center 1 may be configured to generate a signal control parameter for controlling the display of the signal lamp 5a installed at the intersection A by the method described in Patent Document 2.

In addition, the number of inflows Q1 and saturation DS1 at the entrance of the inflow link at the intersection A, and the number of outflows Q2 and saturation DS2 at the exit of the inflow link at the intersection A are not the above-described image processing, Further, it may be obtained by a loop coil type vehicle detection sensor embedded in the exit, an ultrasonic type vehicle detection sensor provided at the entrance and exit of the link, or the like. The number of inflows Q1 is the number of vehicles detected by a loop coil type vehicle detection sensor embedded in the entrance of the inflow link at the intersection A, an ultrasonic vehicle detection sensor provided at the entrance of the link, or the like. The number of outflows Q2 is the number of vehicles detected by a loop coil type vehicle detection sensor embedded at the exit of the inflow link at the intersection A, an ultrasonic type vehicle detection sensor provided at the exit of the link, or the like. The saturation DS1 at the entrance of the inflow link at the intersection A is indicated by the loop coil type vehicle detection sensor embedded at the entrance of the inflow link at the intersection A, the ultrasonic vehicle detection sensor provided at the entrance of the link, etc. By using the total time T1 and the number Q1 of inflows during which the vehicle is detected during the above period (the period from the inflow vehicle detection start timing to the inflow vehicle detection end timing), it can be calculated from the following equation.
DS1 = (g- (T1-t1 * Q1)) / g
However, t1 is the inter-vehicle time (saturated traffic flow rate) per vehicle at the time of saturated flow, and is a value set in advance in consideration of road conditions and the like.

Similarly, the saturation DS2 at the exit of the inflow link at intersection A is determined by the loop coil type vehicle detection sensor embedded at the exit of the inflow link at intersection A, the ultrasonic vehicle detection sensor provided at the exit of the link, or the like. By using the total time T2 and the number of outflows Q2 during which the vehicle is detected during the present period (the above-described period from the outflow vehicle detection start timing to the outflow vehicle detection end timing), it can be calculated from the following equation.
DS2 = (g- (T2-t2 * Q2)) / g
However, t2 is the inter-vehicle time (saturated traffic flow rate) per vehicle at the time of saturated flow, and is a value set in advance in consideration of road conditions and the like.

  In this case, the configuration related to the image processing described above is not necessary.

  Further, the outflow side image sensor 2a and the inflow side image sensor 2b are configured to detect the above-described total times T1 and T2 by image processing, and the saturation DS1 at the entrance of the inflow link at the intersection A is used as the total time T1. The saturation degree DS2 at the exit of the inflow link at the intersection A may be calculated from the above expression using the total time T2. In this case, the above-described processing for obtaining the representative value V1 of the speed of the vehicle that has flowed into the inflow link at the intersection A according to s6, or the representative value V2 of the speed of the vehicle that has flowed out from the inflow link at the intersection A according to s16. The process of acquiring is no longer necessary.

  In addition, the configuration for obtaining the saturation DS1 at the entrance of the inflow link at the intersection A and the saturation DS2 at the exit of the inflow link at the intersection A may be a configuration other than the above.

  Further, the outflow side image sensor 2a and the inflow side image sensor 2b may be configured as one image sensor 2 as shown in FIG. The image sensor 2 includes a control unit 21, an image input unit 22, an image processor 23, and an input / output unit 24. The control unit 21 has the functions of the control units 21a and 21b described above. The image input unit 22 has the functions of the image input units 22a and 22b described above. The image processor 23 has the functions of the image processors 23a and 23b described above. The input / output unit 24 performs communication related to data input / output with the traffic control center 1 and the signal control devices 3a and 3b.

  The image sensor 2 may be provided in the traffic control center 1.

  As shown in FIG. 9, the imaging area of the video camera 20a is sized to include the exit of the inflow link at the intersection A and the entrance of the inflow link at the intersection B, and the imaging area of the video camera 20b is the size of the inflow link of the intersection A. The size may include the entrance and the exit of the inflow link at the intersection B. In this case, the outflow side image sensor 2a performs the processing shown in FIG. 6 on the inflow link at the intersection B in addition to the processing shown in FIG. 7, and the inflow side image sensor 2b shows the processing shown in FIG. In addition to the processing, the processing shown in FIG. 7 may be executed on the inflow link at intersection B. In this way, the inflow link at intersection A and the inflow at intersection B shown in FIG. The number of staying vehicles can be estimated for the link.

  In FIG. 9, only the branch path connected to the inflow link at the intersection B is not shown.

  Moreover, you may enable it to set beforehand the time slot | zone which performs the process shown in FIG. 6 and FIG. For example, the processing shown in FIG. 6 and FIG. 7 may be set to be executed in a commuting time zone where traffic congestion is likely to occur. Also, the processing shown in FIGS. 6 and 7 may be set not to be executed in a midnight time zone or the like where traffic congestion is unlikely to occur.

DESCRIPTION OF SYMBOLS 1 ... Traffic control center 2 ... Image sensor 2a ... Outflow side image sensor 2b ... Inflow side image sensor 3a, 3b ... Signal control apparatus 5a, 5b ... Signal lamp 11 ... Control unit 12 ... Signal control parameter generation unit 13 ... Input / output unit 20a, 20b ... Video camera 21, 21a, 21b ... Control unit 22, 22a, 22b ... Image input unit 23, 23a, 23b ... Image processor 24, 24a, 24b ... Input / output unit 231a, 231b ... Vehicle tracking unit 232a, 232b ... Passing number acquisition unit 233a, 233b ... Vehicle speed acquisition unit 234a, 234b ... DS acquisition unit

Claims (14)

A staying number measuring device for estimating the number of vehicles staying in a link to which at least one of an inflow path into which a vehicle flows in or an outflow path from which a vehicle flows out is connected between an inlet and an outlet,
At the entrance of the link, the inflow quantity acquisition unit that acquires the number of vehicle which has flowed into the link,
Outflow number acquisition unit for acquiring the number of vehicles that have flowed out of the link at the exit of the link;
An entrance-side saturation acquisition unit that acquires the saturation of the entrance of the link;
The number of vehicles that have flowed into the link acquired by the inflow number acquisition unit, the number of vehicles that have flowed out of the link acquired by the outflow number acquisition unit, and the entrance of the link acquired by the entrance side saturation acquisition unit of the saturation, using, and a number of vehicles estimator for estimating the number of vehicles remaining in the said link,
The vehicle number estimation unit is the saturation of the entrance of the link acquired by the entrance side saturation acquisition unit, and the number of vehicles that have flowed into the link acquired by the inflow number acquisition unit, or the outflow number acquisition unit is A staying number measuring device that corrects at least one of the number of vehicles that have flowed out of the acquired link . An exit-side saturation acquisition unit that acquires the saturation of the exit of the link;
The vehicle number estimation unit stays in the link when it is determined that the exit of the link is oversaturated based on the saturation of the exit of the link acquired in the exit side saturation acquisition unit. The staying number measuring device according to claim 1 , wherein the number of vehicles is estimated .   3. The staying number measuring device according to claim 1, wherein the inflow number acquisition unit processes a detection output of a sensor that senses an entrance of the link to acquire the number of vehicles that have flowed into the link.   3. The staying number measuring device according to claim 1, wherein the inflowing number acquisition unit acquires a number of vehicles that have flowed into the link by processing a captured image obtained by imaging the entrance of the link.   The said outflow number acquisition part processes the detection output of the sensor which senses the exit of the said link, and acquires the number of the vehicles which flowed out of the said link, The staying number measuring apparatus in any one of Claims 1-4 .   The said outflow number acquisition part processes the picked-up image which imaged the exit of the said link, and acquires the number of the vehicles which flowed out from the said link, The staying number measuring apparatus in any one of Claims 1-4. The said entrance side saturation acquisition part processes the detection output of the sensor which senses the entrance of the said link, and acquires the saturation degree of the entrance of the said link, The residence number measurement in any one of Claims 1-6 apparatus. The said entrance side saturation acquisition part processes the picked-up image which imaged the entrance of the said link, and acquires the saturation of the entrance of the said link, The residence number measurement apparatus in any one of Claims 1-6. A speed acquisition unit that acquires a representative value of the speed of the vehicle that has flowed into the link at the entrance of the link;
The entrance-side saturation acquisition unit uses the number of vehicles that have flowed into the link acquired by the inflow number acquisition unit and a representative value of the speed of the vehicle that has flowed into the link acquired by the speed acquisition unit. The staying number measuring device according to claim 1, wherein the degree of saturation at the entrance of the link is acquired.   The staying number according to any one of claims 1 to 9, wherein the speed acquisition unit processes a detection output of a sensor that senses the entrance of the link to acquire a representative value of a speed of the vehicle that has flowed into the link. Measuring device.   The staying number measuring apparatus according to any one of claims 1 to 9, wherein the speed acquisition unit processes a captured image obtained by imaging the entrance of the link and acquires a representative value of the speed of the vehicle that has flowed into the link. . For controlling the display of the signal lamp that restricts the travel of the vehicle that flows out from the exit of the link to which at least one of the inflow path where the vehicle flows in or the outflow path where the vehicle flows out is connected between the entrance and the exit A signal control system for generating a signal control parameter to be used,
At the entrance of the link, the inflow quantity acquisition unit that acquires the number of vehicle which has flowed into the link,
Outflow number acquisition unit for acquiring the number of vehicles that have flowed out of the link at the exit of the link;
An entrance-side saturation acquisition unit that acquires the saturation of the entrance of the link;
The number of vehicles that have flowed into the link acquired by the inflow number acquisition unit, the number of vehicles that have flowed out of the link acquired by the outflow number acquisition unit, and the entrance of the link acquired by the entrance side saturation acquisition unit A vehicle number estimation unit that estimates the number of vehicles staying in the link using the degree of saturation of
Using the number of vehicles staying at the link estimated by the number-of-vehicles estimation unit, a signal control parameter used for controlling the display of the signal lamp that restricts the traveling of the vehicle flowing out from the exit of the link is generated. comprising a signal control parameter generation section that, the,
The vehicle number estimation unit is the saturation of the entrance of the link acquired by the entrance side saturation acquisition unit, and the number of vehicles that have flowed into the link acquired by the inflow number acquisition unit, or the outflow number acquisition unit is A signal control system for correcting at least one of the number of vehicles that have flowed out of the acquired link . A method for measuring the number of staying units for estimating the number of vehicles staying in a link to which at least one of an inflow path through which a vehicle flows in or an outflow path from which a vehicle flows out is connected between an entrance and an exit,
At the entrance of the link, and the inflow quantity acquiring step of acquiring the number of vehicles which has flowed into the link,
An outflow number acquisition step of acquiring the number of vehicles that have flowed out of the link at the exit of the link;
An entrance-side saturation acquisition step of acquiring the entrance saturation of the link;
The number of vehicles that have flowed into the link acquired in the inflow number acquisition step, the number of vehicles that have flowed out of the link acquired in the outflow number acquisition step, and the link entrance acquired in the inlet side saturation level acquisition step by using the degree of saturation, and have a number of vehicles estimation step of estimating the number of vehicles remaining in the said link,
The vehicle number estimating step is the saturation at the entrance of the link acquired at the entrance-side saturation acquisition step, the number of vehicles flowing into the link acquired at the inflow unit acquisition step, or the outflow number acquiring step. A staying number measuring method , which is a step of correcting at least one of the number of vehicles that have flowed out of the acquired link . A staying number measurement program for estimating the number of vehicles staying in a link to which at least one of an inflow path through which a vehicle flows in or an outflow path from which a vehicle flows out is connected between an inlet and an outlet,
At the entrance of the link, and the inflow quantity acquiring step of acquiring the number of vehicles which has flowed into the link,
An outflow number acquisition step of acquiring the number of vehicles that have flowed out of the link at the exit of the link;
An entrance-side saturation acquisition step of acquiring the entrance saturation of the link;
The number of vehicles that have flowed into the link acquired in the inflow number acquisition step, the number of vehicles that have flowed out of the link acquired in the outflow number acquisition step, and the link entrance acquired in the inlet side saturation level acquisition step And a vehicle number estimation step for estimating the number of vehicles staying in the link using the degree of saturation of
The vehicle number estimating step is the saturation at the entrance of the link acquired at the entrance-side saturation acquisition step, the number of vehicles flowing into the link acquired at the inflow unit acquisition step, or the outflow number acquiring step. A staying number measurement program , which is a step of correcting at least one of the number of vehicles that have flowed out of the acquired link .

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