JP2014006696A - Monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect occurrence of traffic congestion with high accuracy.SOLUTION: A monitoring system 10 comprises: a plurality of imaging devices 100, each of which has an imaging unit 110 for imaging a vehicle image in which a vehicle traveling on a road is included; and a data management device 200 having a transmission/reception unit 210 for transmitting/receiving data to/from the plurality of imaging devices 100. Each of the plurality of imaging devices 100 includes: a vehicle state detection unit 120 for detecting a vehicle state of a vehicle on the basis of a plurality of vehicle images that are imaged at predetermined time intervals; and a vehicle state transmission/reception unit 130 for transmitting a vehicle state to the data management device. The data management device 200 includes a traffic congestion determination unit 220 for determining the fact that traffic congestion occurs on the basis of the vehicle state received from the plurality of imaging devices that have transmitted the vehicle state.

Description

  The present invention relates to a monitoring system that monitors a situation of a vehicle traveling on a road by a plurality of photographing devices.

  2. Description of the Related Art Conventionally, there is known a monitoring system that measures the traveling speed of a vehicle by transmitting an image captured using a camera installed in a tunnel to an image processing device and extracting the characteristics of the vehicle in the image processing device ( For example, see Patent Document 1).

  A monitoring device that detects the position of the end of a traffic jam based on an image taken using a camera installed along a road is also known (see, for example, Patent Document 2).

JP 2003-272086 A JP 2010-136031 A

  However, the image processing apparatus in the conventional monitoring system is photographed by a large number of photographing apparatuses in order to detect the traveling speed of the vehicle in a traffic jam, the length of the traffic jam, and the position of the traffic jam occurrence with high accuracy. Images had to be acquired and analyzed. Therefore, in the conventional monitoring system, in order to transmit an image photographed by each photographing apparatus to the image processing apparatus, each photographing apparatus and the image processing apparatus are connected by a plurality of communication lines having a high communication speed. It was necessary to do.

  However, there is a problem that high cost is required to install a communication line with a high communication speed between each photographing apparatus and image processing apparatus. In order to control costs, it was necessary to reduce the resolution of images that can be used for analysis and to use inexpensive communication lines, widen the interval between image capture devices, and reduce the frequency of image capture. There was a problem that the monitoring accuracy of the vehicle situation was lowered.

  Therefore, the present invention has been made in view of these points, and an object of the present invention is to provide a monitoring system that can monitor a vehicle state with high accuracy using an inexpensive communication line.

  In order to solve the above-described problem, according to the present invention, a plurality of imaging devices having imaging units that capture a vehicle image including a vehicle traveling on a road, and transmission and reception of data between the plurality of imaging devices. A vehicle status detection unit that detects a vehicle status of a vehicle based on a plurality of vehicle images captured at a predetermined time interval. A vehicle status transmission / reception unit that transmits the vehicle status to the data management device, and the data management device determines that traffic congestion has occurred based on the vehicle status received from the plurality of imaging devices that transmitted the vehicle status. A monitoring system having a traffic jam judgment unit is provided.

  As an example, the vehicle state detection unit described above detects the vehicle speed of the vehicle based on the vehicle image, and determines that there is a possibility of traffic jam when the vehicle speed is smaller than the vehicle speed threshold. The vehicle status transmission / reception unit transmits a traffic jam notification indicating that there is a possibility of traffic jam to the data management device, and the traffic jam determination unit determines that traffic jam has occurred based on the traffic jam notification.

  The data management device may further include an average speed calculation unit that calculates an average vehicle speed obtained by averaging a plurality of vehicle speeds acquired from a plurality of imaging devices. For example, the traffic jam determination unit determines that a traffic jam has occurred when the average vehicle speed is smaller than an average speed threshold greater than or equal to the vehicle speed threshold. The average speed calculation unit may calculate the average vehicle speed using the vehicle speed received from the adjacent imaging device as the vehicle speed corresponding to the imaging device that has not received the vehicle speed.

  The data management device includes a traffic jam distance calculation unit that calculates a traffic jam distance based on the position of the imaging device that transmitted the vehicle status, and a time required for the traffic jam to pass based on the vehicle speed and the traffic jam distance received from a plurality of imaging devices. And a transit time calculation unit for calculating The data management device further includes a traffic jam distance calculation unit that calculates a traffic jam distance based on the position of the photographing device that transmitted the vehicle status, and the traffic jam determination unit generates a traffic jam when the traffic jam distance is longer than a distance threshold. May be determined.

  The vehicle state detection unit detects the inter-vehicle distances of a plurality of vehicles based on the vehicle image, determines that there is a possibility of traffic jam when the inter-vehicle distance is smaller than the inter-vehicle distance threshold, and the data management device You may further have an average inter-vehicle distance calculation part which calculates the average inter-vehicle distance which averaged the following inter-vehicle distance. For example, the traffic jam determination unit determines that traffic jam has occurred when the average inter-vehicle distance is smaller than the average inter-vehicle distance threshold.

  In addition, the vehicle status detection unit may detect a vehicle status indicating that the vehicle occupies an area larger than a predetermined ratio in the vehicle image. The vehicle status transmission / reception unit of the imaging device may transmit the vehicle status according to the result of the vehicle status detection unit detecting the vehicle status over a predetermined time.

  The transmission / reception unit of the data management device transmits a request message for requesting the vehicle status to a predetermined number of imaging devices provided upstream of the imaging device that transmitted the vehicle status, and the congestion determination unit transmits the request message. It may be determined whether or not a traffic jam has occurred based further on the vehicle situation received from a predetermined number of imaging devices.

  The transmission / reception unit transmits a request message for requesting the vehicle status to the plurality of imaging devices between the first imaging device and the second imaging device that transmitted the vehicle status, and the traffic jam determination unit Further, it may be determined whether or not a traffic jam has occurred based on the vehicle status received from the plurality of imaging devices that transmitted.

  The traffic jam judgment unit receives a vehicle situation from a plurality of imaging devices out of a predetermined number among a plurality of imaging devices installed in a predetermined section, and traffic congestion occurs in a section in which the predetermined number of imaging devices are installed. You may determine that you did. When the traffic determination unit receives the vehicle status from a plurality of imaging devices more than a predetermined ratio among the plurality of imaging devices included between the imaging devices at both ends of the plurality of imaging devices that have transmitted the vehicle status, It may be determined that a traffic jam has occurred between the imaging devices.

  According to the present invention, the vehicle status can be monitored with high accuracy using an inexpensive communication line.

1 shows a configuration example of a monitoring system according to a first embodiment. An example of usage of the monitoring system according to the first embodiment is shown. The example of installation to the tunnel of the some imaging device in a monitoring system is shown. 2 shows an example of the configuration of an imaging apparatus and a data management apparatus according to the first embodiment. The method by which an imaging device detects vehicle speed is shown. The method by which an imaging device detects the distance between vehicles is shown. The other structural example of the monitoring system of this embodiment is shown. An example of the communication sequence between a some imaging device and a data management apparatus is shown. The other example of the communication sequence between a some imaging device and a data management apparatus is shown. The structural example of the monitoring system of 2nd Embodiment is shown. The other structural example of the monitoring system of 2nd Embodiment is shown. A method for generating a combined image will be described. The other structural example of the monitoring system of 2nd Embodiment is shown. A method for detecting a tracking target vehicle will be described. The structural example of the monitoring system of 3rd Embodiment is shown.

<First Embodiment>
[Basic configuration of the monitoring system]
FIG. 1 shows a configuration example of a monitoring system 10 according to the first embodiment. FIG. 2A shows an example of how the monitoring system 10 of the first embodiment is used. FIG. 2B shows an installation example of a plurality of imaging devices 100 in the tunnel 500 in the monitoring system 10.

  The monitoring system 10 includes, for example, a plurality of imaging devices 100 (imaging devices 100-1, 100-2,..., An imaging device 100-n, where n is a natural number of 3 or more) connected in a daisy chain. And a data management device 200 connected to the photographing device 100. The data management device 200 is a server, for example. A plurality of imaging devices 100 are connected by a communication line 50. The communication line 50 is an 8-core cable for LAN (local area network), for example.

  The monitoring system 10 may include a hub 300 between the data management device 200 and the imaging device 100-1. Each photographing apparatus 100 may be connected to the data management apparatus 200 via the hub 300. The monitoring system 10 may include a plurality of groups of a plurality of imaging devices 100 connected to the hub 300. The monitoring system 10 may include a monitor 400 that displays a vehicle situation acquired by the data management apparatus 200 from the imaging apparatus 100. Here, the vehicle status refers to the traveling speed of the vehicle photographed by the photographing apparatus 100 (hereinafter referred to as vehicle speed), the distance between a plurality of vehicles (hereinafter referred to as inter-vehicle distance), and the vehicle in the image photographed by the photographing apparatus 100. It is information indicating the traveling state of the vehicle, such as a ratio (hereinafter, vehicle density).

  Each of the plurality of imaging devices 100 captures a vehicle image including a vehicle traveling on a road. Each imaging device 100 detects a vehicle situation based on the photographed vehicle image, and transmits at least one of the detected vehicle image and vehicle situation to the data management device 200. The data management device 200 may transmit control information for controlling the imaging device 100, and may receive at least one of a vehicle image and a vehicle situation transmitted by the plurality of imaging devices 100 according to the control information.

  As an example, a plurality of imaging devices 100 are installed in a tunnel 500, and an image or video of a vehicle traveling in the tunnel 500, or a vehicle situation detected by the imaging device 100 based on the image or video is data. It transmits to the management apparatus 200. In this specification, the side where the vehicle approaches one of the plurality of imaging devices 100 is referred to as upstream, and the side where the vehicle moves away is referred to as downstream.

[Configuration Example of Imaging Device 100 and Data Management Device 200]
FIG. 3 shows a configuration example of the imaging device 100 and the data management device 200 of the first embodiment. The imaging apparatus 100 includes an imaging unit 110, a vehicle situation detection unit 120, and a vehicle situation transmission / reception unit 130. The data management apparatus 200 includes a transmission / reception unit 210 and a traffic jam determination unit 220.

  The imaging unit 110 captures a vehicle image including a vehicle traveling on the road. For example, the imaging unit 110 includes a lens and a CCD (charge coupled device). The imaging unit 110 may include a plurality of lenses provided side by side in a direction parallel to the traveling direction of the vehicle, and may capture a plurality of vehicle images via each lens.

  The vehicle situation detection unit 120 detects the situation of the vehicle photographed by the photographing unit 110 based on a plurality of vehicle images photographed at predetermined time intervals. For example, the vehicle status detection unit 120 detects the vehicle speed based on the position of the vehicle shown in the vehicle images taken at different timings. The vehicle situation detection unit 120 may detect the inter-vehicle distances of a plurality of vehicles shown in the vehicle image as the vehicle situation. The vehicle status detection unit 120 may detect the ratio of the area occupied by the vehicle in the vehicle image as the vehicle status.

  When the imaging unit 110 captures a plurality of vehicle images via a plurality of lenses, the vehicle state detection unit 120 uses the plurality of vehicle images captured at the same time by the imaging unit 110 using the plurality of lenses. In addition, the vehicle situation such as the inter-vehicle distance may be detected. The vehicle situation detection unit 120 can detect the vehicle situation with higher accuracy by analyzing the images based on the plurality of vehicle images photographed through the plurality of lenses.

  The vehicle status transmission / reception unit 130 transmits the vehicle status detected by the vehicle status detection unit 120 to the data management device 200. For example, the vehicle status transmission / reception unit 130 periodically transmits information indicating the vehicle speed detected by the vehicle status detection unit 120 to the data management device 200. The vehicle status transmission / reception unit 130 may transmit information indicating the inter-vehicle distance and the ratio of the area occupied by the vehicle in the vehicle image to the data management apparatus 200.

  The vehicle status transmission / reception unit 130 may transmit the vehicle status to the data management device 200 via the vehicle status transmission / reception unit 130 of the adjacent imaging device 100. For example, the vehicle status transmission / reception unit 130 of the imaging device 100-2 is adjacent to the vehicle status received from the vehicle status detection unit 120 and the vehicle status received from the vehicle status transmission / reception unit 130 of the adjacent imaging device 100-3. It transmits to the vehicle condition transmission / reception part 130 of the imaging device 100-1. The vehicle status transmission / reception unit 130 receives either the vehicle status received from the vehicle status detection unit 120 or the vehicle status received from the vehicle status transmission / reception unit 130 of the imaging device 100-3. There may be a switching hub for switching between transmission and reception.

  The transmission / reception unit 210 transmits / receives data to / from the plurality of imaging devices 100. For example, the transmission / reception unit 210 receives the vehicle status transmitted by the vehicle status transmission / reception unit 130 via the hub 300. The transmission / reception unit 210 may receive the vehicle status transmitted by one imaging device 100 via another imaging device 100 connected in a daisy chain.

  The traffic jam determination unit 220 determines that traffic jam has occurred based on the vehicle status received from the plurality of imaging devices 100 that transmitted the vehicle status. For example, the traffic jam determination unit 220 determines that traffic jam has occurred based on at least one of a plurality of vehicle speeds and a plurality of inter-vehicle distances received from the plurality of imaging devices 100. Specifically, the traffic jam determination unit 220 has a traffic jam in the case where the vehicle speed received from the plurality of imaging devices 100 is smaller than a predetermined threshold and in at least one case where the inter-vehicle distance is smaller than the predetermined threshold. Is determined to have occurred. When the traffic jam determination unit 220 determines that traffic jam has occurred, the traffic jam determination unit 220 may display on the monitor 400 that the traffic jam has occurred.

  When the traffic determination unit 220 receives the vehicle status from a plurality of imaging devices 100 that are determined according to the installation interval of the imaging devices 100 among the plurality of imaging devices 100 installed in the predetermined section, the traffic congestion determination unit 220 receives the predetermined number of vehicles. It may be determined that a traffic jam has occurred in the section where the photographing apparatus 100 is installed. For example, when a plurality of imaging devices 100 are installed at intervals of 2 m, the traffic congestion determination unit 220 receives traffic from more than half of the imaging devices 100 installed in a predetermined section and receives traffic. Is determined to have occurred. When a plurality of photographing devices 100 are installed at an interval of 10 m, the traffic jam determination unit 220 may determine that a traffic jam has occurred when vehicle conditions are received from all the photographing devices 100.

  When the traffic jam determination unit 220 receives vehicle conditions from more than a predetermined ratio of the plurality of imaging devices 100 included in each group obtained by dividing the plurality of imaging devices 100, a congestion occurs in the group. You may determine that you did. The traffic jam determination unit 220 may determine that traffic jam has occurred in a section including all groups when the number of groups determined to have traffic jam or the ratio of the total group count to the number of all groups is larger than a predetermined value.

  The traffic jam determination unit 220 determines the vehicle status from a plurality of imaging devices 100 that are more than a predetermined ratio among the plurality of imaging devices 100 included between the imaging devices 100 at both ends of the plurality of imaging devices 100 that transmitted the vehicle status. When received, it may be determined that a traffic jam has occurred between the imaging devices 100 at both ends.

[Method of detecting vehicle speed in photographing apparatus 100]
FIG. 4 shows an example of a method for the photographing apparatus 100 to detect the vehicle speed. FIG. 4 shows a vehicle image taken at time t1 by the photographing unit 110 and a vehicle image taken at time t2. The distance between the leading position of the vehicle at time t1 and the leading position of the vehicle at time t2 is d1. In this case, the vehicle state detection unit 120 can detect the vehicle speed by (t2-t1) / d1. The vehicle status detection unit 120 may detect the vehicle speed based on a position other than the head position of the vehicle.

  The vehicle state detection unit 120 may determine that there is a possibility of traffic jam when the detected vehicle speed is smaller than the vehicle speed threshold. For example, the vehicle state detection unit 120 determines that there is a possibility of traffic jam when the speed is lower than the speed notified in advance from the data management device 200.

  It is preferable that the image capturing unit 110 captures a vehicle image at a time interval included in two or more vehicle images captured by the image capturing unit 110 when the vehicle travels at a speed smaller than the vehicle speed threshold. Specifically, the imaging unit 110 sets the length in the traveling direction of the vehicle (hereinafter referred to as imaging width) that can be captured by the imaging unit 110, W as the vehicle speed threshold, and the time interval for imaging the vehicle image (hereinafter referred to as imaging interval). ) Is Δt, it is preferable to take a vehicle image at a shooting interval Δt that satisfies the relationship of V × Δt <W / 2.

  When the imaging unit 110 captures images at the time intervals described above, a specific part of the vehicle traveling at a speed smaller than the vehicle speed threshold is included in the two vehicle images captured by the imaging unit 110. Therefore, one imaging device 100 can detect the speed of a vehicle that travels at a speed smaller than the vehicle speed threshold.

  The imaging unit 110 may capture a vehicle image at a time interval according to the imaging width W and the vehicle speed threshold V notified from the data management device 200 based on the relationship of V × Δt <W / 2. For example, when W is 10 m and the vehicle speed threshold is 40 km / h (11.1 m / s), the imaging unit 110 captures a vehicle image at a time interval within Δt = 0.45 seconds. The imaging unit 110 may set the imaging interval when the vehicle speed threshold is 20 km / h to 0.90 seconds, which is twice the imaging interval when the vehicle speed threshold is 40 km / h.

  When the vehicle status detection unit 120 determines that there is a possibility of traffic jam, the vehicle status transmission / reception unit 130 may transmit a traffic jam notification indicating the possibility of traffic jam to the data management device 200. For example, when the vehicle speed detected by the vehicle condition detection unit 120 is equal to or higher than the vehicle speed threshold, the vehicle status transmission / reception unit 130 does not transmit data to the data management device 200, and the vehicle speed is lower than the vehicle speed threshold. When it is small, the vehicle speed is transmitted to the data management device 200 together with the traffic jam notification. The traffic jam determination unit 220 may determine that a traffic jam has occurred when a traffic jam notification is received from the vehicle status transmission / reception unit 130. It is preferable that the traffic jam determination unit 220 determines that a traffic jam has occurred when a traffic jam notification is received from the plurality of vehicle status transmission / reception units 130.

  The vehicle status transmission / reception unit 130 may transmit the vehicle status to the data management device 200 according to the result of the vehicle status detection unit 120 detecting the vehicle status over a predetermined time. For example, when the situation in which the vehicle speed detected by the vehicle situation detection unit 120 is lower than the vehicle speed threshold value continues for one minute, the vehicle situation transmission / reception unit 130 sends at least one of the traffic jam notification and the vehicle speed to the data management device 200. Send.

  When the average speed of the vehicle speed detected by the vehicle status detection unit 120 within a predetermined time is smaller than the vehicle speed threshold, the vehicle status transmission / reception unit 130 outputs at least one of the traffic jam notification and the vehicle speed to the data management device 200. May be sent to. As described above, the vehicle status transmission / reception unit 130 determines whether or not to transmit the vehicle status based on the detection result of the vehicle status over a predetermined period of time. It is possible to prevent the vehicle status from being transmitted to the data management device 200.

[Detection method of inter-vehicle distance in photographing apparatus 100]
FIG. 5 shows an example of a method in which the photographing apparatus 100 detects the inter-vehicle distance. In FIG. 5, the distance between the rear end position of the first vehicle and the front end position of the second vehicle that are reflected in the vehicle image taken by the photographing apparatus 100 is d2. In such a case, the vehicle state detection unit 120 detects the inter-vehicle distance as d2.

  The vehicle state detection unit 120 may determine that there is a possibility of traffic jam when the detected inter-vehicle distance is smaller than the inter-vehicle distance threshold. For example, the vehicle state detection unit 120 determines that there is a possibility of traffic jam when the detected inter-vehicle distance is smaller than the inter-vehicle distance threshold D notified in advance from the data management device 200.

  The imaging unit 110 captures a vehicle image so that two vehicles traveling at an inter-vehicle distance smaller than the inter-vehicle distance threshold are included in the vehicle images captured by the respective imaging devices 100. Specifically, the imaging unit 110 captures a vehicle image over an imaging width W that is greater than the inter-vehicle distance threshold D. It is preferable that the imaging unit 110 captures a vehicle image having an imaging width W that is twice or more the inter-vehicle distance threshold D.

  As described above, in the monitoring system 10 according to the first embodiment, the data management device 200 determines whether or not a traffic jam has occurred based on the vehicle conditions such as the vehicle speed and the inter-vehicle distance detected by the plurality of imaging devices 100. Therefore, even when the capacity of the communication line between the plurality of imaging devices 100 and the data management device 200 is small, it is possible to detect the occurrence of traffic congestion with high accuracy.

[Determining the presence or absence of traffic jam based on the average value of the vehicle status of the plurality of imaging devices 100]
FIG. 6 shows another configuration example of the monitoring system 10 of the present embodiment. The data management device 200 in the monitoring system 10 illustrated in FIG. 6 further includes at least one of an average speed calculation unit 230, an average inter-vehicle calculation unit 240, a traffic jam distance calculation unit 250, and a passing time calculation unit 260. Different from the monitoring system 10 shown in FIG.

  The average speed calculation unit 230 calculates an average vehicle speed obtained by averaging a plurality of vehicle speeds acquired from the plurality of imaging devices 100. For example, after the transmission / reception unit 210 receives a traffic jam notification from one imaging device 100, the average speed calculation unit 230 issues a traffic jam notification within a time required for the vehicle status detection unit 120 to determine whether or not there is a traffic jam possibility. An average value of vehicle speeds received from the plurality of imaging devices 100 that have received is calculated. The average speed calculation unit 230 may calculate the average vehicle speed using the vehicle speed received from the adjacent imaging device 100 as the vehicle speed corresponding to the imaging device 100 that has not received the vehicle speed. The average speed calculation unit 230 may calculate the average vehicle speed using the legal speed as the vehicle speed corresponding to the imaging device 100 that has not received the vehicle speed.

  The traffic jam determination unit 220 may determine that traffic jam has occurred when the average vehicle speed calculated by the average speed calculation unit 230 is smaller than the average speed threshold. The average speed threshold may be the same as the vehicle speed threshold, or may be larger than the vehicle speed threshold. When the average vehicle speed is smaller than the average speed threshold, the traffic congestion determination unit 220 is between the most downstream imaging device 100 and the most upstream imaging device 100 among the plurality of imaging devices 100 that have transmitted the traffic jam notification. It may be determined that a traffic jam has occurred.

  The average inter-vehicle distance calculation unit 240 calculates an average inter-vehicle distance obtained by averaging a plurality of inter-vehicle distances acquired from the plurality of imaging devices 100. The traffic jam determination unit 220 may determine that a traffic jam has occurred when the average inter-vehicle distance calculated by the average inter-vehicle distance calculation unit 240 is smaller than the average inter-vehicle distance threshold.

  The traffic jam determination unit 220 may determine the degree of traffic jam based on the average vehicle speed and the average inter-vehicle distance. For example, the traffic jam determination unit 220 determines that the traffic is a first degree of traffic jam when the average vehicle speed is smaller than the average speed threshold, the average vehicle speed is equal to or greater than the average speed threshold, and the average inter-vehicle distance is the average inter-vehicle distance. When it is smaller than the threshold value, it is determined that the second degree of traffic jam (congestion). The traffic jam determination unit 220 may determine that no traffic jam has occurred when the average vehicle speed is equal to or greater than the average speed threshold and the average inter-vehicle distance is equal to or greater than the average inter-vehicle distance threshold.

[Communication sequence between photographing apparatus 100 and data management apparatus 200]
FIG. 7 shows an example of a communication sequence between the plurality of imaging devices 100 and the data management device 200. When each of the imaging device 100-1, the imaging device 100-2, the imaging device 100-3, and the imaging device 100-4 detects that the vehicle speed is smaller than the vehicle speed threshold, the vehicle status with respect to the data management device 200 Send. When the average speed of the plurality of vehicle speeds included in the plurality of vehicle situations received from the respective image capturing apparatuses 100 is smaller than the average speed threshold, the data management apparatus 200 includes the image capturing apparatus 100-1 and the image capturing apparatus 100-4. It is determined that there has been a traffic jam.

  FIG. 8 shows another example of a communication sequence between the plurality of imaging devices 100 and the data management device 200. In the communication sequence illustrated in FIG. 8, the imaging device 100-2 and the imaging device 100-3 are transmitted although the imaging device 100-1 and the imaging device 100-4 transmit the vehicle status to the data management device 200. Does not transmit the vehicle status to the data management device 200. The reason why the photographing device 100-2 and the photographing device 100-3 are not transmitting the vehicle status is that the vehicle speed detected by the photographing device 100-2 and the photographing device 100-3 is equal to or higher than the vehicle speed threshold, or It is conceivable that the photographing apparatus 100-2 and the photographing apparatus 100-3 are out of order.

  Therefore, the transmission / reception unit 210 is between the first imaging device 100 (for example, the most downstream imaging device 100) and the second imaging device 100 (for example, the most upstream imaging device 100) that transmitted the vehicle status. A request message for requesting the vehicle status may be transmitted to the plurality of imaging devices 100. The traffic jam determination unit 220 determines whether or not a traffic jam has occurred based further on the vehicle status received from the plurality of imaging devices 100 that transmitted the request message. Specifically, the traffic jam determination unit 220 transmits the vehicle status in response to the vehicle speed detected by the imaging device 100-1 and the imaging device 100-4 that have transmitted the traffic jam notification, and the request message. It may be determined that a traffic jam has occurred when the average value of the vehicle speeds detected by 100-2 and the imaging device 100-3 is smaller than the average vehicle speed threshold.

  In this case, the average vehicle speed detected by the imaging device 100-2 and the imaging device 100-3 may be larger than the vehicle speed threshold. Therefore, the average speed calculation unit 230 may determine that a traffic jam has occurred when the average speed threshold value is smaller than the average speed threshold value greater than the vehicle speed threshold value.

[Send message requesting vehicle status]
The traffic determination unit 220 transmits a request message to the imaging device 100 between the most downstream imaging device 100 and the most upstream imaging device 100 that transmitted the traffic jam notification, and the vehicle received in response to the request message. A section between the most downstream imaging device 100 and the most upstream imaging device 100 that has transmitted the traffic jam notification when the rate of the imaging device 100 whose speed is lower than the predetermined threshold is greater than the predetermined rate. It may be determined that a traffic jam has occurred.

  The transmission / reception unit 210 may transmit a request message for requesting the vehicle status to a predetermined number of the imaging devices 100 provided upstream of the imaging device 100 that has transmitted the vehicle status. When the transmission / reception unit 210 receives the traffic jam notification from the imaging device 100-1, the imaging device 100-2, the imaging device 100-3, and the imaging device do not wait for the time required for the imaging device 100 to detect the traffic jam notification. By promptly transmitting a request message to 100-4, the data management device 200 can quickly acquire the vehicle status.

  For example, the data management device 200 uses a vehicle situation notified from the imaging device 100 installed at a point where the traffic congestion is likely to occur from an uphill to a downhill or a location where the traffic is changed from a downhill to an uphill as a trigger. By making the determination, it is possible to quickly detect that a natural traffic jam has occurred.

  When the transmission / reception unit 210 transmits a request message to the N imaging devices 100 upstream of the imaging device 100-1, the average speed calculation unit 230 transmits the imaging device 100-1 to the imaging device 100-k (k is The average vehicle speed may be calculated based on the vehicle speed received from the imaging device 100 (an integer from 2 to N). When the average vehicle speed calculated based on the vehicle speed received from the imaging device 100 from the imaging device 100-1 to the imaging device 100-k is smaller than the average vehicle threshold, the traffic jam determination unit 220 is the imaging device 100-. It may be determined that a traffic jam has occurred between 1 and the photographing apparatus 100-k.

  The imaging device 100 may transmit a state cancellation notification for notifying that there is a possibility that the traffic jam has been resolved to the data management device 200 when the state where the traffic jam is likely to be resolved. The transmission / reception unit 210 may transmit a request message for requesting the vehicle status to a predetermined number of imaging devices 100 provided upstream of the imaging device 100 that has transmitted the congestion cancellation notification. The traffic jam determination unit 220 may determine that the traffic jam has been resolved based on the vehicle status received from the imaging device 100 that transmitted the request message. For example, when the average value of the vehicle speed received from the plurality of imaging devices 100 is larger than the average vehicle speed threshold, or when the average value of the inter-vehicle distance is larger than the average inter-vehicle distance threshold, the traffic jam determination unit 220 Is determined to have been resolved.

[Calculate traffic distance and traffic time]
The traffic jam distance calculation unit 250 calculates the traffic jam distance based on the position of the imaging device 100 that transmitted the vehicle status. For example, the traffic jam distance calculation unit 250 sets the distance between the most downstream imaging device 100 that transmitted the vehicle status and the most upstream imaging device 100 as the traffic jam distance. As shown in FIG. 2B, when the identification numbers corresponding to the respective positions of the plurality of imaging devices 100 are attached, the traffic jam distance calculation unit 250 and the most downstream imaging device 100 that transmitted the vehicle situation are the most. Each imaging device 100 has a value obtained by adding 1 to the number of imaging devices 100 between the most downstream imaging device 100 and the most upstream imaging device 100 calculated based on the identification number of the upstream imaging device 100. The congestion distance may be calculated by multiplying the distance between them.

  The traffic jam determination unit 220 may determine that a traffic jam has occurred when the traffic jam distance calculated by the traffic jam distance calculation unit 250 is longer than a predetermined distance threshold. The traffic jam determination unit 220 may determine that traffic jam has occurred when the average vehicle speed is smaller than the average speed threshold and the traffic jam distance is longer than the distance threshold.

  The passing time calculation unit 260 calculates the time required for passing the traffic jam based on the vehicle speed and the traffic jam distance received from the plurality of imaging devices 100. For example, the passing time calculation unit 260 calculates the time required to pass through the traffic jam section by dividing the traffic jam distance calculated by the traffic jam distance calculation unit 250 by the average vehicle speed calculated by the average speed calculation unit 230.

[Effect of the first embodiment]
As described above, in the monitoring system 10 of the first embodiment, the vehicle status detected by the plurality of imaging devices 100 is transmitted to the data management device 200, and the data management device 200 receives from the plurality of imaging devices 100. It can be determined that a traffic jam has occurred based on the vehicle status. For example, when the imaging apparatus 100 determines that there is a possibility of traffic jam based on the vehicle status such as the vehicle speed and the inter-vehicle distance detected by the imaging apparatus 100, the vehicle status is transmitted to the data management apparatus 200, thereby The management device 200 can determine a traffic jam with high accuracy even when the communication capacity of the communication line is small.

<Second Embodiment>
[Several photographing apparatuses 100 transmit vehicle images]
FIG. 9 shows a configuration example of the monitoring system 10 of the second embodiment. As shown in FIG. 1, the plurality of photographing apparatuses 100 are connected in a daisy chain, for example. The imaging apparatus 100 shown in FIG. 9 is different from the imaging apparatus 100 shown in FIG. 3 in that it has a vehicle image transmission / reception unit 140 instead of the vehicle situation detection unit 120 and the vehicle situation transmission / reception unit 130, and is the same in other respects. is there. The data management device 200 shown in FIG. 9 is different from the data management device 200 shown in FIG. The data management apparatus 200 may further include an average speed calculation unit 230 and an average inter-vehicle calculation unit 240.

  The vehicle image transmission / reception unit 140 transmits a plurality of vehicle images taken at a predetermined time interval to the data management apparatus 200. For example, the vehicle image transmission / reception unit 140 transmits a plurality of vehicle images captured by the imaging unit 110 at time intervals specified by the data management device 200. The vehicle image transmission / reception unit 140 selects a vehicle image corresponding to the time interval specified by the data management device 200 from the vehicle images captured by the imaging unit 110 at intervals shorter than the time interval specified by the data management device 200. Then, the data may be transmitted to the data management apparatus 200. The vehicle image transmission / reception unit 140 may attach the time information at which the vehicle image was captured to the vehicle image and transmit it to the data management device 200.

  The vehicle image transmission / reception unit 140 may transmit the vehicle image to the data management device 200 via the vehicle image transmission / reception unit 140 of the adjacent imaging device 100. For example, the vehicle image transmission / reception unit 140 of the imaging device 100-2 receives the vehicle image received from the imaging unit 110 and the vehicle image received from the vehicle image transmission / reception unit 140 of the adjacent imaging device 100-3. It transmits to the vehicle image transmission / reception part 140 of 100-1. The vehicle image transmission / reception unit 140 transmits any of the vehicle image received from the imaging unit 110 and the vehicle image received from the vehicle image transmission / reception unit 140 of the imaging device 100-3 to the vehicle image transmission / reception unit 140 of the imaging device 100-1. You may have a switching hub which changes.

  When the imaging unit 110 captures a plurality of vehicle images via a plurality of lenses, the vehicle image transmission / reception unit 140 is a data management device that uses a single packet to capture a plurality of vehicle images captured at the same time by a plurality of lenses. 200 may be transmitted. The vehicle image transmission / reception unit 140 may transmit a plurality of vehicle images by different packets when the degree of congestion of the communication line 50 exceeds a threshold, and transmits only one vehicle image among the plurality of vehicle images. May be.

  The traffic jam determination unit 220 determines that traffic jam has occurred based on vehicle images received from the plurality of imaging devices 100. For example, the vehicle state detection unit 270 detects at least one of the vehicle speeds of the plurality of vehicles and the inter-vehicle distances of the plurality of vehicles based on the plurality of vehicle images taken at predetermined time intervals. The traffic jam determination unit 220 determines that traffic jam has occurred based on at least one of the vehicle speed and the inter-vehicle distance detected by the vehicle status detection unit 270.

  Specifically, the vehicle state detection unit 270 may detect the vehicle speed based on the amount of change in the position of a single vehicle shown in the vehicle image captured by the imaging device 100 at a plurality of different times. More specifically, as shown in FIG. 4, when the distance between the vehicle head position at time t1 and the vehicle head position at time t2 is d1, as shown in FIG. -T1) The vehicle speed is detected by / d1. As shown in FIG. 5, when the distance between the rear end position of the first vehicle and the front end position of the second vehicle in the vehicle image taken by the photographing apparatus 100 is d2, the vehicle state detection is performed. The unit 270 may detect the inter-vehicle distance as d2.

  The traffic jam determination unit 220 may determine that traffic jam has occurred at the position of the imaging device 100 corresponding to the vehicle image indicating that the vehicle occupies an area larger than a predetermined ratio in the vehicle image. For example, the vehicle state detection unit 270 detects the contour line of the vehicle in the vehicle image, and calculates the ratio of the number of pixels inside the contour line to the number of pixels in the entire vehicle image. The traffic jam determination unit 220 determines that traffic jam has occurred when the ratio of the number of pixels inside the contour calculated by the vehicle status detection unit 270 is greater than the threshold.

  The average speed calculation unit 230 calculates an average vehicle speed obtained by averaging the vehicle speeds of the plurality of vehicles detected based on the plurality of vehicle images acquired by the vehicle state detection unit 270 from the plurality of imaging devices 100. The traffic jam determination unit 220 may determine that traffic jam has occurred when the average vehicle speed is smaller than the average speed threshold. The average speed calculation unit 230 calculates an average vehicle speed using the vehicle speed received from the image capturing apparatus 100 adjacent to the image capturing apparatus 100 as the vehicle speed corresponding to the image capturing apparatus 100 that captured the vehicle image whose vehicle speed cannot be detected. May be. The average speed calculation unit 230 may calculate the average vehicle speed using the legal speed as the vehicle speed corresponding to the imaging device 100 that has captured the vehicle image for which the vehicle speed cannot be detected.

  The average inter-vehicle distance calculation unit 240 calculates an average inter-vehicle distance obtained by averaging a plurality of inter-vehicle distances detected based on a plurality of vehicle images acquired by the vehicle state detection unit 270 from the plurality of imaging devices 100. The traffic jam determination unit 220 may determine that traffic jam has occurred when the average inter-vehicle distance is smaller than the average inter-vehicle threshold.

  The data management device 200 may further include at least one of a traffic jam distance calculation unit 250 and a passage time calculation unit 260. The congestion distance calculation unit 250 determines the congestion distance based on the position of the imaging device 100 that has captured the vehicle image including at least one state in which the vehicle speed is smaller than the speed threshold and the inter-vehicle distance is smaller than the inter-vehicle distance threshold. Is calculated. Specifically, the traffic jam distance calculation unit 250 captures a vehicle image including at least one state in which the vehicle speed is smaller than the speed threshold and the inter-vehicle distance is smaller than the inter-vehicle distance threshold. The distance between the most downstream photographing device 100 and the most upstream photographing device 100 may be a traffic jam distance. The traffic jam determination unit 220 may determine that a traffic jam has occurred when the traffic jam distance is longer than the distance threshold.

  The passage time calculation unit 260 calculates the time required for passing the traffic jam based on the vehicle speed and the traffic jam distance detected by the vehicle status detection unit 270 based on the plurality of vehicle images received from the plurality of imaging devices 100.

  In order for the data management device 200 to accurately determine whether or not a traffic jam has occurred based on a plurality of vehicle images captured by the plurality of imaging devices 100, the plurality of imaging devices 100 may capture the vehicle images at the same timing. preferable. Thus, the plurality of daisy chain-connected imaging devices 100 acquire a synchronization signal that provides timing for capturing a vehicle image from the adjacent imaging device 100 and notify the other adjacent imaging devices 100 of the synchronization signal. Also good.

[Detect traffic jam based on combined image]
FIG. 10 shows another configuration example of the monitoring system 10 of the second embodiment. The data management apparatus 200 illustrated in FIG. 10 is different from the monitoring system 10 illustrated in FIG. 9 in that the combined image generation unit 280 is further included.

  The combined image generation unit 280 generates a combined image obtained by combining a plurality of vehicle images. As an example, the combined image generation unit 280 generates a combined image by superimposing regions where the same subject is captured in a plurality of vehicle images.

  FIG. 11 shows a combined image generation method. FIG. 11 shows images taken by the photographing apparatus 100-1, the photographing apparatus 100-2, and the photographing apparatus 100-3 at the same time. As shown in FIG. 2A, a part of the area captured by each imaging device 100 overlaps each other. Therefore, the vehicle b is reflected in both the vehicle image photographed by the photographing apparatus 100-1 and the vehicle image photographed by the photographing apparatus 100-2. Therefore, the combined image generation unit 280 deletes the image in the region on the right side of the position indicated by the dotted line from the vehicle images photographed by the photographing device 100-1, and the vehicle image photographed by the photographing device 100-2. Among them, the combined image is generated by deleting the image in the region on the left side of the position indicated by the dotted line.

  The traffic jam determination unit 220 may determine that traffic jam has occurred when the number of vehicles included in a predetermined area in the combined image generated by the combined image generation unit 280 is greater than the predetermined number. For example, the traffic jam determination unit 220 determines that traffic jam has occurred in an area where the number of vehicles included in each area in the combined image divided into a plurality of areas is greater than a threshold number determined according to the length of the area. judge. The traffic jam determination unit 220 may determine that traffic jam has occurred when the number of vehicles is greater than the threshold number over a predetermined period.

  The combined image generation unit 280 may generate a plurality of combined images corresponding to a plurality of vehicle images taken at different times. The vehicle state detection unit 270 may detect the vehicle speed based on the position of the vehicle in the plurality of combined images and the time interval at which the vehicle images included in the plurality of combined images are taken.

  The average speed calculation unit 230 calculates the average vehicle speed by averaging the vehicle speeds of a plurality of vehicles included in the combined image. The average speed calculation unit 230 may calculate the average vehicle speed in a predetermined period based on a plurality of combined images including vehicle images photographed over a predetermined time. The traffic jam determination unit 220 determines that traffic jam has occurred when the average vehicle speed is smaller than the average vehicle speed threshold.

  The vehicle state detection unit 270 detects inter-vehicle distances between a plurality of vehicles included in the combined image. The average inter-vehicle distance calculation unit 240 calculates the average inter-vehicle distance by averaging a plurality of inter-vehicle distances included in the combined image. The average speed calculation unit 230 may calculate an average inter-vehicle distance in a predetermined period based on a plurality of combined images including vehicle images photographed over a predetermined time. The traffic jam determination unit 220 may determine that traffic jam has occurred when the average inter-vehicle distance is smaller than the average inter-vehicle distance threshold.

  The combined image generation unit 280 may generate a combined image based on a plurality of vehicle images taken at time intervals according to a vehicle speed threshold that is used as a reference for determining whether or not the traffic jam has occurred. . Specifically, the combined image generation unit 280 preferably generates a combined image using vehicle images taken at smaller time intervals when the vehicle speed threshold is smaller.

[Track one vehicle]
FIG. 12 shows another configuration example of the monitoring system 10 according to the second embodiment. The data management device 200 shown in FIG. 12 is different from the data management device 200 shown in FIG. 9 in that it has a tracking vehicle detection unit 290 instead of the average speed calculation unit 230, the average inter-vehicle calculation unit 240, and the vehicle condition detection unit 270. Different.

  The tracking vehicle detection unit 290 is a tracking target vehicle in the vehicle image captured by the first imaging device 100-1 and the vehicle image captured by the second imaging device 100-2 other than the first imaging device 100. Detect the image. The traffic determination unit 220 is based on the time difference between the time when the vehicle image including the tracking target vehicle is captured by the first imaging device 100-1 and the time when the vehicle image is captured by the second imaging device 100-2. It is determined that a traffic jam has occurred. For example, the traffic jam determination unit 220 may determine that traffic jam has occurred when the time difference is larger than the time threshold.

  FIG. 13 shows a method of detecting a tracking target vehicle. First, the tracking vehicle detection unit 290 selects the vehicle b shown in the image captured by the imaging device 100-4 at the time t1 as the tracking target vehicle. Subsequently, the tracking vehicle detection unit 290 searches for an image of the vehicle b in the vehicle image photographed by the photographing device 100-3 on the downstream side of the photographing device 100-4.

  Next, the tracking vehicle detection unit 290 indicates that the vehicle b is shown at the same position as the position of the image of the vehicle b in the vehicle image of the imaging device 100-4 in the vehicle image of the imaging device 100-3 at time t2. To detect. Furthermore, the tracking vehicle detection unit 290 detects that the vehicle b appears in the same position as the position of the image of the vehicle b in the vehicle image of the imaging device 100-4 in the vehicle image of the imaging device 100-2 at time t3. To do.

  When the plurality of photographing devices 100 are installed at equal intervals, the difference in time at which the vehicle b appears in the plurality of adjacent photographing devices 100 is inversely proportional to the vehicle speed. Therefore, the traffic jam determination unit 220 determines that traffic jam has occurred when at least one of the time difference between the time t2 and the time t1 and the time difference between the time t3 and the time t2 is greater than a predetermined time. It's okay. The traffic jam determination unit 220 may determine that traffic jam has occurred when a plurality of time differences are larger than a predetermined time, or when an average value of the plurality of time differences is larger than a predetermined time.

  The tracking vehicle detection unit 290 may calculate the vehicle speed of the tracking target vehicle based on the time difference when the plurality of imaging devices 100 capture the tracking target vehicle and the distance between the plurality of imaging devices 100. The traffic jam determination unit 220 may determine that traffic jam has occurred when the vehicle speed calculated by the tracking vehicle detection unit 290 is smaller than the vehicle speed threshold.

[Effects of Second Embodiment]
As described above, in the monitoring system 20 of the second embodiment, the data management device 200 detects the occurrence of a traffic jam based on a plurality of vehicle images taken at a predetermined time interval by the imaging device 100. Therefore, since it is not necessary for the photographing apparatus 100 to analyze the vehicle image, the cost of the photographing apparatus 100 can be reduced.

  In particular, in the monitoring system 20, since a plurality of imaging devices 100 are connected in a daisy chain, the two adjacent imaging devices 100 and the data management device 200 are not connected by a communication line. Vehicle images captured by a plurality of imaging devices 100 can be transmitted to the data management device 200 while the imaging devices 100 are connected via communication lines to reduce the cost of the communication lines.

<Third Embodiment>
[Transmit vehicle image to data management apparatus 200 when there is a possibility of traffic jam]
FIG. 14 shows a configuration example of the monitoring system 30 of the third embodiment. The monitoring system 30 is different from the monitoring system 20 illustrated in FIG. 10 in that the photographing apparatus 100 includes a vehicle condition detection unit 120 and a vehicle condition transmission / reception unit 130.

  The vehicle status transmission / reception unit 130 in the monitoring system 30 transmits the vehicle status detected by the vehicle status detection unit 120 to the data management device 200 and also the vehicle image captured by the imaging unit 110 in response to a request from the data management device 200. Is transmitted to the data management apparatus 200. When the data management apparatus 200 receives the vehicle status from the predetermined number of imaging apparatuses 100, the data management apparatus 200 requests vehicle images from all of the imaging apparatuses 100. For example, when the data management apparatus 200 receives a traffic jam notification from the imaging apparatus 100 that detects a vehicle speed smaller than the vehicle speed threshold or an inter-vehicle distance smaller than the inter-vehicle distance threshold, the data management apparatus 200 requests vehicle images from all the imaging apparatuses 100. .

  When the combined image generation unit 280 receives vehicle images from the plurality of imaging devices 100, the combined image generation unit 280 generates a combined image based on the received vehicle images. The traffic jam determination unit 220 may determine whether or not a traffic jam has occurred based on the generated combined image. The traffic jam determination unit 220 may determine whether or not a traffic jam has occurred based on the average vehicle speed calculated by the average speed calculation unit 230 based on the combined image and the average inter-vehicle distance calculated by the average inter-vehicle distance calculation unit 240.

[Effect of the third embodiment]
As described above, according to the monitoring system 30 of the third embodiment, when it is detected that there is a possibility of traffic jam in one imaging device 100, a vehicle is transferred from the plurality of imaging devices 100 to the data management device 200. The image can be transmitted and the data management apparatus 200 can generate a combined image. Therefore, it is not necessary to transmit the vehicle image to the data management device 200 even though the possibility of traffic jam is low, so that the power consumption of the imaging device 100 and the data management device 200 can be reduced.

  In the above embodiment, the imaging device 100 and the data management device 200 are described as devices having different configurations. However, even if the image capturing apparatus 100 includes the configuration of the data management apparatus 200 and one of the plurality of image capturing apparatuses 100 functions as the data management apparatus 200, the same effects can be obtained.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Monitoring system, 20 ... Monitoring system, 30 ... Monitoring system, 50 ... Communication line, 100 ... Imaging apparatus, 110 ... Imaging part, 120 ... Vehicle condition detection part , 130: Vehicle status transmission / reception unit, 140: Vehicle image transmission / reception unit, 200 ... Data management device, 210 ... Transmission / reception unit, 220 ... Congestion determination unit, 230 ... Average speed calculation unit , 240 ... average inter-vehicle distance calculation section, 250 ... traffic jam distance calculation section, 260 ... transit time calculation section, 270 ... vehicle condition detection section, 280 ... combined image generation section, 290 ... Tracking vehicle detection unit, 300 ... hub, 400 ... monitor, 500 ... tunnel

Claims (13)

A plurality of photographing devices having a photographing unit for photographing a vehicle image including a vehicle traveling on a road;
A monitoring system comprising: a data management device having a transmission / reception unit for transmitting and receiving data to and from the plurality of imaging devices;
Each of the plurality of photographing devices is
A vehicle situation detector that detects a vehicle situation of the vehicle based on a plurality of the vehicle images taken at a predetermined time interval;
A vehicle status transmission / reception unit that transmits the vehicle status to the data management device;
The data management device includes:
The monitoring system which has a traffic congestion determination part which determines with the traffic condition having occurred based on the said vehicle condition received from the said several imaging device which transmitted the said vehicle condition. The vehicle state detection unit detects the vehicle speed of the vehicle based on the vehicle image, determines that there is a possibility of traffic jam when the vehicle speed is smaller than a vehicle speed threshold,
The vehicle status transmission / reception unit transmits a traffic jam notification indicating that there is a possibility of traffic jam to the data management device,
The monitoring system according to claim 1, wherein the traffic jam determination unit determines that the traffic jam has occurred based on the traffic jam notification. The data management device includes:
An average speed calculating unit that calculates an average vehicle speed obtained by averaging the plurality of vehicle speeds acquired from the plurality of imaging devices;
The monitoring system according to claim 2, wherein the traffic jam determination unit determines that the traffic jam has occurred when the average vehicle speed is smaller than an average speed threshold greater than or equal to the vehicle speed threshold.   The said average speed calculation part calculates the said average vehicle speed using the said vehicle speed received from the said imaging device adjacent as the said vehicle speed corresponding to the said imaging device which has not received the said vehicle speed. The monitoring system described. The data management device includes:
A traffic jam distance calculation unit that calculates a traffic jam distance based on the position of the imaging device that transmitted the vehicle status;
5. A transit time calculation unit that calculates a time required for the traffic to pass based on the vehicle speed and the traffic jam distance received from the plurality of imaging devices. 5. Monitoring system. The data management device further includes a traffic jam distance calculation unit that calculates a traffic jam distance based on the position of the photographing device that has transmitted the vehicle status,
The monitoring system according to any one of claims 1 to 4, wherein the traffic jam determination unit determines that the traffic jam has occurred when the traffic jam distance is longer than a distance threshold. The vehicle state detection unit detects the inter-vehicle distances of the plurality of vehicles based on the vehicle image, and determines that there is a possibility of traffic jam when the inter-vehicle distance is smaller than the inter-vehicle distance threshold,
The data management device further includes an average inter-vehicle distance calculation unit that calculates an average inter-vehicle distance obtained by averaging a plurality of the inter-vehicle distances,
The monitoring system according to any one of claims 1 to 6, wherein the traffic jam determining unit determines that the traffic jam has occurred when the average inter-vehicle distance is smaller than an average inter-vehicle distance threshold.   The monitoring system according to any one of claims 1 to 7, wherein the vehicle situation transmission / reception unit transmits the vehicle situation according to a result of the vehicle situation detection unit detecting the vehicle situation over a predetermined time. . The transmitting / receiving unit transmits a request message for requesting the vehicle status to a predetermined number of the imaging devices provided upstream of the imaging device that has transmitted the vehicle status,
The said traffic congestion determination part determines whether the said traffic congestion generate | occur | produced further based on the said vehicle condition received from the said predetermined number of imaging devices which transmitted the said request message. The monitoring system described. The transmission / reception unit transmits a request message for requesting the vehicle status to the plurality of imaging devices between the first imaging device and the second imaging device that transmitted the vehicle status,
The said traffic congestion determination part determines whether the said traffic congestion generate | occur | produced further based on the said vehicle condition received from the said some imaging device which transmitted the said request message. Monitoring system.   When the traffic condition determination unit receives the vehicle status from a plurality of the plurality of imaging devices out of a plurality of the imaging devices installed in a predetermined section, the predetermined number of the imaging devices are installed. The monitoring system according to claim 1, wherein it is determined that the traffic jam has occurred in the section.   The traffic jam determination unit is configured to transmit the vehicle from a plurality of the plurality of photographing apparatuses included in the plurality of photographing apparatuses at both ends of the plurality of photographing apparatuses that have transmitted the vehicle status. The monitoring system according to any one of claims 1 to 11, wherein when a situation is received, it is determined that the traffic jam has occurred between the imaging devices at both ends. The monitoring system according to any one of claims 1 to 12, wherein the vehicle status detection unit detects a ratio of an area occupied by the vehicle in the vehicle image as the vehicle status.

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