JP2014078148A - Photographing device and congestion determination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine whether congestion occurs or not in a short time, without transmitting large quantities of image data.SOLUTION: A photographing device comprises: a photographing section 110 for photographing a prescribed area; a measurement section 121 for measuring the number of vehicles photographed by the photographing section 110 in a prescribed measurement period; a calculation section 122 for calculating a speed of at least any vehicle among the vehicles photographed by the photographing section 110 in the measurement period; and an output section 123 for outputting alarm information indicating a possibility of a congestion occurrence when the speed calculated by the calculation section 122 is lower than a predetermined reference speed in a case where the number of vehicles measured by the measurement section 121 is equal to or more than a prescribed number of vehicles.

Description

  The present invention relates to an imaging device that captures a vehicle traveling on a road, and a traffic jam determination system that determines the occurrence of traffic jam based on an image of the vehicle captured by the imaging device.

  Traditionally, the average speed and number of vehicles that have passed through multiple sensors installed along the road are measured, and the traffic conditions based on the temporal or spatial distribution of statistical parameters generated based on the measurement results There is known a device for monitoring a traffic jam that detects an abnormality in the vehicle (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 10-320686

  However, in the conventional traffic jam monitoring device, in order to detect the conditions such as the traveling speed of the vehicle in the traffic jam, the length of the traffic jam, and the location of the traffic jam with high accuracy, images taken by a number of imaging devices for a long time are required. Had to acquire over and analyze the acquired images. For example, when determining the occurrence of a traffic jam based on the average speed of a predetermined number of vehicles, it may take a long time to measure the speed of the predetermined number of vehicles.

  Furthermore, in the conventional traffic monitoring device, the occurrence of traffic jam is determined by analyzing images captured by a large number of imaging devices, so the images captured by a large number of imaging devices are aggregated and analyzed on a computer. Had to do. Therefore, in order to transmit a large amount of image data between a large number of photographing apparatuses and a computer, there is a problem that the large number of photographing apparatuses and the computer have to be connected by a large capacity communication line.

  Therefore, the present invention has been made in view of these points, and provides an imaging device and a traffic jam determination system that can determine in a short time whether or not there is a traffic jam without transmitting a large amount of image data. For the purpose.

  In order to solve the above problems, in the first aspect of the present invention, a photographing unit that photographs a predetermined region, a measuring unit that measures the number of vehicles photographed by the photographing unit within a predetermined measurement period, Of the vehicles photographed by the photographing unit within the measurement period, a calculation unit that calculates at least one of the speeds, and a speed calculated by the calculation unit when the number of units measured by the measurement unit is equal to or greater than a predetermined number are predetermined. And an output unit that outputs alarm information indicating a possibility that a traffic jam has occurred when the speed is lower than the reference speed.

  The calculating unit calculates the speed of at least a predetermined number of vehicles when the number of vehicles measured by the measuring unit is greater than or equal to a predetermined number, and the output unit outputs at least one of the calculated speeds below the reference speed In this case, alarm information may be output.

  In addition, when the number of vehicles measured by the measurement unit is equal to or greater than the predetermined number, the calculation unit calculates a speed of at least the predetermined number of vehicles, and is photographed by the photographing unit based on the calculated speed. Calculate the average speed of the vehicle, and if the number of vehicles measured by the measurement unit is less than the predetermined number, calculate the speed of all the vehicles photographed by the photographing unit and subtract the number of vehicles photographed from the predetermined number It is assumed that the number of vehicles obtained at the time was traveling at a predetermined assumed speed, and shooting was performed based on the speed of the vehicle shot by the shooting unit and the estimated speed of the number of vehicles obtained by subtraction. The average speed of the vehicle photographed by the unit may be calculated, and the output unit may output alarm information when the average speed calculated by the calculation unit is less than a predetermined reference speed.

  In addition, when the number of vehicles measured by the measurement unit is less than a predetermined number, the above calculation unit uses an assumed speed determined based on the number of vehicles measured by the measurement unit and the speed of the vehicle. An average speed may be calculated.

  The imaging device includes an acquisition unit that acquires information from an imaging device arranged upstream of the traffic flow, and the calculation unit determines whether the measurement unit determines that the number of vehicles measured by the measurement unit is less than a predetermined number. The average speed may be calculated using an assumed speed determined based on the measured number of vehicles and information acquired by the acquisition unit. In addition, the photographing apparatus may further include a measurement period determining unit that changes the measurement period based on the speed of the vehicle that has been photographed earliest calculated by the calculation unit.

  The above measurement unit periodically measures the number of vehicles photographed within the measurement period, and the output unit is based on the speed of the vehicle photographed within the measurement period in any of a plurality of consecutive measurement periods. If it is less than the speed, alarm information may be output.

  The above-described photographing apparatus includes a storage control unit that associates the time when the vehicle is photographed by the photographing unit and the speed of the vehicle calculated by the calculation unit, and accumulates and stores them in the storage unit as measurement information, and a storage unit Based on a plurality of measurement information stored in the measurement unit, an average speed calculation unit that calculates an average speed of the vehicle imaged by the imaging unit during the measurement period, and a measurement based on the plurality of measurement information stored in the storage unit An inter-vehicle distance calculating unit that calculates an average inter-vehicle distance of a vehicle imaged by the imaging unit within a period, and the output unit is when the average inter-vehicle distance is less than a predetermined distance when the average speed is less than the reference speed, Alarm information may be further output.

  According to the second aspect of the present invention, a photographing unit that photographs a predetermined region, a measuring unit that measures the number of vehicles photographed by the photographing unit, and a calculation unit that calculates the speed of the vehicle photographed by the photographing unit. And a number determination unit for determining the number of vehicles whose speed is to be measured based on the speed of the vehicle photographed earliest calculated by the calculation unit, and alarm information based on the speed calculated by the calculation unit And an output unit, wherein the calculation unit calculates an average speed of the number of vehicles determined by the determination unit, and the output unit outputs alarm information when the average speed is less than a predetermined reference speed. I will provide a.

  According to the third aspect of the present invention, any one of the plurality of imaging devices described above, a data processing device connected to at least one of the plurality of imaging devices via a communication line and processing data received from the plurality of imaging devices, The output unit of the plurality of imaging devices outputs alarm information in association with the identification information of the imaging device, and when the data processing device acquires the alarm information from any of the plurality of imaging devices, a traffic jam occurs. Provided is a traffic jam determination system including a traffic jam determination unit that determines whether or not

  According to the present invention, there is an effect that it is possible to determine in a short time whether there is a possibility of congestion without transmitting a large amount of image data.

It is a figure which shows the structural example of the traffic congestion determination system which concerns on 1st Embodiment. It is a figure which shows an example of the usage condition of the traffic congestion determination system which concerns on 1st Embodiment. It is a figure which shows the example of installation to the tunnel of the some imaging device in a traffic congestion determination system. It is a figure which shows the structural example of the imaging device which concerns on 1st Embodiment. It is a figure which shows an example of the method for a calculation part to detect vehicle speed. It is a table | surface which shows the distance between vehicles corresponding to the number of vehicles image | photographed within the measurement period of 10 second, and vehicle speed. It is a figure which shows the other structural example of the imaging device which concerns on 2nd Embodiment. It is a figure which shows the structural example of the imaging device which concerns on 3rd Embodiment. It is a figure which shows the structural example of the imaging device which concerns on 4th Embodiment. It is a figure which shows the structural example of the imaging device which concerns on 5th Embodiment.

<First Embodiment>
[Outline of the traffic congestion judgment system 10]
FIG. 1 is a diagram illustrating a configuration example of a traffic jam determination system 10 according to the first embodiment. FIG. 2 is a diagram illustrating an example of a usage mode of the traffic jam determination system 10 according to the first embodiment. FIG. 3 is a diagram illustrating an installation example of a plurality of imaging devices 100 in the tunnel 500 in the traffic jam determination system 10.

  The traffic jam determination 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. A data processing device 200 connected to a plurality of photographing devices 100 is provided. The data processing device 200 is a server, for example. The plurality of imaging devices 100 are connected by communication lines 50 (communication lines 50-1,..., Communication lines 50-n). The communication line 50 is an 8-core cable for LAN (local area network), for example.

  The traffic jam determination system 10 includes a hub 300 between the data processing device 200 and the imaging device 100-1. Each photographing apparatus 100 is connected to the data processing apparatus 200 via the hub 300. The traffic jam determination system 10 includes a plurality of groups of imaging devices 100 connected to the hub 300, for example. The traffic jam determination system 10 includes a monitor 400 that displays an image acquired by the data processing apparatus 200 from the imaging apparatus 100.

  Each of the plurality of imaging devices 100 captures an image including a vehicle traveling on a road. Each photographing apparatus 100 detects the speed of the vehicle based on the photographed image, and outputs alarm information indicating the possibility of traffic jam based on the detected speed. The imaging device 100 can notify the administrator of the imaging device 100 or the traffic jam determination system 10 and the driver of the traveling vehicle that there is a possibility that a traffic jam has occurred by outputting alarm information.

  As an example, as shown in FIG. 3, the plurality of image capturing apparatuses 100 are installed in a tunnel 500 and are based on an image or video captured of a vehicle traveling in the tunnel 500, or based on the captured image or video. The alarm information output from the imaging device 100 is transmitted to the data processing device 200. In this specification, as shown in FIG. 3, the side on which the vehicle approaches one of the plurality of imaging devices 100 is referred to as upstream, and the side on which the vehicle moves away is referred to as downstream.

[Configuration Example of Imaging Device 100]
FIG. 4 is a diagram illustrating a configuration example of the imaging apparatus 100 according to the first embodiment. The photographing apparatus 100 includes a photographing unit 110 and a control unit 120. The control unit 120 is, for example, a microprocessor that operates as the measurement unit 121, the calculation unit 122, and the output unit 123 by executing a program stored in a storage medium.

  The photographing unit 110 photographs a predetermined area around the photographing apparatus 100 and generates an 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 includes, for example, a plurality of lenses provided side by side in a direction parallel to the lane, and captures a plurality of images via each lens.

  The measurement unit 121 measures the number of vehicles photographed by the photographing unit 110 within a predetermined measurement period. Specifically, the measurement unit 121 measures the number of vehicles that have passed through a predetermined position in the area captured by the imaging unit 110 during a preset measurement time (for example, 10 seconds). For example, the measurement unit 121 compares the first image and the second image continuously captured by the imaging unit 110, and the vehicle that has not been captured in the predetermined area in the first image corresponds to the second image. When it is reflected in the predetermined area, it is determined that one vehicle has passed the predetermined position. The measurement unit 121 measures the number of vehicles by counting the number of vehicles that have passed a predetermined position during the measurement period.

  The calculation unit 122 calculates at least one of the speeds of the vehicles photographed by the photographing unit 110 during the measurement period in which the measurement unit 121 measures the number of vehicles. For example, the calculation unit 122 calculates the speed of the leading vehicle among vehicles photographed within the measurement period. Since the speed at which a vehicle travels is not much different from the speed of a vehicle traveling before and after the vehicle, if at least one of the captured vehicles is calculated, a plurality of vehicles before and after the vehicle are calculated. Can be estimated.

  When the number of vehicles measured by the measurement unit 121 is equal to or greater than a predetermined number, the calculation unit 122 may calculate at least the speed of the predetermined number of vehicles. The calculation unit 122 may calculate an average speed of a plurality of vehicles photographed within the measurement period.

  FIG. 5 is a diagram illustrating an example of a method by which the calculation unit 122 calculates the vehicle speed. In FIG. 5, an image taken by the photographing unit 110 at time t1 and an image taken at time t2 are shown. 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 calculation unit 122 can calculate the speed of the vehicle by (t2−t1) / d1. The calculation unit 122 may calculate the speed of the vehicle on the basis of a position other than the head position of the vehicle.

  In order to reduce the amount of calculation, the calculation unit 122 estimates the position where the vehicle is captured in the image captured by the imaging unit 110, and specifies the position of the vehicle based on the image of the area around the estimated position. Also good. For example, when the calculation unit 122 detects the vehicle A for the first time in the image shot at time t1, the image pattern of the vehicle A is searched for in the entire area of the image in the image shot at time t2 of the next shooting timing. Then, the position of the vehicle A in the image is specified. The calculation unit 122 estimates the speed of the vehicle A based on the position of the vehicle A in the image captured at time t1, the position of the vehicle A in the image captured at time t2, and the time difference between the time t1 and time t2. A value (hereinafter, estimated speed) is calculated.

  Subsequently, the calculation unit 122 estimates the position in the image captured at time t3, which is the next imaging timing after time t2, when the vehicle A moves from the position of the vehicle A at time t2 at the estimated speed. Specifically, the calculation unit 122 has taken a position at time t3 that is a distance away from the position of vehicle A at time t2 by a distance obtained by multiplying the time difference between time t3 and time t2 by the estimated speed. The position of the vehicle A in the image is estimated. The calculation unit 122 searches for an image pattern of the vehicle A in a region around the estimated position.

  When the number of estimated speeds calculated by the calculation unit 122 increases, an estimated speed with higher accuracy can be calculated based on a plurality of estimated speeds. Therefore, the calculation unit 122 can calculate the image pattern of the vehicle A as time passes. The area to search for may be narrowed. As described above, the calculation unit 122 can reduce the calculation amount by narrowing the search range of the image pattern used for calculating the speed of the vehicle A based on the estimated speed of the vehicle A.

  In the case where the number measured by the measuring unit 121 is equal to or greater than the predetermined number, the output unit 123 may indicate that there is a traffic jam when the speed calculated by the calculating unit 122 is less than a predetermined reference speed. The alarm information indicated is output. When the measurement unit 121 measures the speeds of a plurality of vehicles, the output unit 123 outputs alarm information when at least one of the calculated speeds is less than the reference speed. The output unit 123 may output alarm information when the average speed of the vehicle shown in the image taken within the measurement period is less than the reference speed.

  For example, when the number of units measured by the measuring unit 121 is the first number, the output unit 123 outputs the alarm information when the speed of at least one of the first numbers is less than the first speed. Is output. When the number of units measured by the measuring unit 121 is a second number less than the first number, the output unit 123 has a speed of at least one of the second numbers smaller than the first speed. Alarm information is output when the speed is less than the second speed. Hereinafter, the conditions for the output unit 123 to output alarm information will be described using a specific example.

  FIG. 6 shows the number of vehicles photographed within the measurement period of 10 seconds and the inter-vehicle distance corresponding to the vehicle speed. For example, the calculation unit 122 calculates the inter-vehicle distance illustrated in FIG. 6 based on the number of vehicles and the vehicle speed. In FIG. 6, when the number of vehicles photographed in 10 seconds is 1 to 5, the vehicles traveling at the respective speeds of 50 km / h, 40 km / h, 30 km / h, and 20 km / h traveled at equal intervals. The distance between vehicles is shown. For example, when the vehicle speed is 50 km / h (13.9 m / s), it is considered that there are five vehicles within a distance of 13.9 m × 10 seconds = 139 m, so the leading positions of the two closest vehicles The distance between them is 139 m ÷ 5 units = about 28 m. When the length of the vehicle is 5 m, the inter-vehicle distance is calculated as 28 m−5 m = 23 m.

  Here, assuming that there is a possibility of traffic jam when the inter-vehicle distance is less than 20 m, the output unit 123 is a case where the number of photographed vehicles is five or more, and the calculated vehicle speed is When the speed is 40 km / h or less, alarm information indicating the possibility of traffic jam is output. The output unit 123 outputs alarm information even when the number of photographed vehicles is four or more and the calculated vehicle speed is 30 km / h or less. The output unit 123 outputs alarm information even when the number of photographed vehicles is three or more and the calculated vehicle speed is 20 km / h or less. The output unit 123 determines whether or not to output alarm information, for example, using a table as shown in FIG. 6 stored in advance in a storage medium such as a memory or a hard disk.

  When the number of units measured by the measuring unit 121 within the measurement period is equal to or greater than the predetermined number, the output unit 123 performs the next measurement when the speed calculated by the calculation unit 122 is equal to or greater than a predetermined first reference speed. The vehicle speed may also be measured during the period, and it may be determined whether or not there is a traffic jam based on the results measured during a plurality of measurement periods. When the speed calculated by the calculation unit 122 is equal to or higher than a second reference speed that is higher than the first reference speed, the output unit 123 determines that there is no traffic jam and determines the number of vehicles in the measurement unit 121. The calculation of the speed in the measurement and calculation unit 122 may be stopped for a predetermined period.

  For example, when the vehicle speed calculated by the calculation unit 122 is 30 km / h or more and less than 50 km / h, the measurement unit 121 measures the vehicle speed for the next 10 seconds, and the vehicle speed calculated by the calculation unit 122 is In the case of 50 km or more, the vehicle speed is not measured for the next 5 minutes. Thus, the measurement part 121 adjusts a measurement space | interval according to a vehicle speed, and can reduce the amount of calculations in the calculation part 122 in a state with low possibility that a traffic jam will generate | occur | produce.

  The measurement unit 121 periodically measures the number of vehicles photographed within the measurement period in order to improve the determination accuracy of occurrence of traffic congestion, and the output unit 123 performs measurement in any of a plurality of consecutive measurement periods. If the speed of the vehicle photographed within the period is less than the reference speed, alarm information may be output. The output unit 123 may output alarm information when the ratio of the measurement period in which the speed of the vehicle photographed within the measurement period is less than the reference speed is greater than a predetermined ratio.

  As described above, according to the photographing apparatus 100 according to the present embodiment, it is possible that a traffic jam has occurred based on the number of photographs taken within a predetermined time and the speed of at least one of the photographed vehicles. The presence or absence of sex can be determined. Therefore, according to this embodiment, for example, it is possible to determine whether or not there is a possibility that a traffic jam has occurred by measurement within a short measurement period of about 10 seconds.

<Second Embodiment>
[Calculate average speed using estimated speed]
In the photographing apparatus 100 according to the first embodiment, the inter-vehicle distance estimated based on the number of vehicles photographed within the measurement period and the speed of at least one of the photographed vehicles is shown. A table was used to determine the possibility of traffic jams. On the other hand, the imaging device 100 according to the present embodiment determines whether or not there is a possibility of congestion based on the average speed of a predetermined number of vehicles after imaging the vehicle within a predetermined measurement period.

  When the number of vehicles measured by the measurement unit 121 is equal to or greater than the predetermined number, the calculation unit 122 calculates the speed of at least the predetermined number of vehicles, and the vehicle photographed by the photographing unit 110 based on the calculated speed. The average speed is calculated. When the number of vehicles measured by the measurement unit 121 is less than the predetermined number, the calculation unit 122 calculates the speeds of all vehicles photographed by the photographing unit 110 and subtracts the number of vehicles photographed from the predetermined number. It is assumed that the number of vehicles obtained at this time was traveling at a predetermined assumed speed. For example, when the number of vehicles measured within a predetermined measurement period is only two, the calculation unit 122 has three vehicles that are less than the predetermined five and the photographing apparatus 100 is installed. It is considered that the car was traveling at the speed limit of the road.

  The calculation unit 122 calculates the average speed of the vehicles photographed by the photographing unit 110 based on the speed of the vehicles photographed by the photographing unit 110 and the estimated speeds of the number of vehicles obtained by subtraction. For example, in the case of the above example, the calculation unit 122 calculates an average speed for five vehicles. For example, when three measured vehicles are traveling at a speed of 30 km / h and the speed limit of the highway on which the photographing apparatus 100 is installed is 80 km / h, the calculation unit 122 calculates the average speed as (30 + 30 + 30 + 80 + 80). ÷ 5 = 50 km / h is calculated. When the measured three vehicles are traveling at 10 km / h and the speed limit of the highway on which the photographing apparatus 100 is installed is 80 km / h, the calculation unit 122 calculates the average speed by (10 + 10 + 10 + 80 + 80) ÷ 5. = Calculated as 38 km / h.

  The output unit 123 outputs alarm information when the average speed calculated by the calculation unit 122 is less than a predetermined reference speed. In the above example, when the average speed calculated by the calculation unit 122 is 50 km / h, the average speed is 40 km / h, which is a speed at which traffic congestion is determined to occur on the highway (hereinafter referred to as traffic jam reference speed). As described above, the output unit 123 does not output alarm information. When the average speed calculated by the calculating unit 122 is 38 km / h, the output unit 123 outputs alarm information because the average speed is less than 40 km / h which is a traffic jam reference speed.

  In the above example, when the number of vehicles measured by the measurement unit 121 is less than the predetermined number, the calculation unit 122 is installed with the imaging device 100 at an estimated speed of the number of vehicles less than the predetermined number. Although the average speed is calculated by setting the speed limit on the road, the calculation unit 122 may set the assumed speed to another speed. For example, when it is preferable that the output unit 123 output alarm information promptly when there is a possibility of traffic jam, the calculation unit 122 assumes that less than a predetermined number of vehicles are traveling at a traffic jam reference speed. The average speed may be calculated.

  Alternatively, when the number of vehicles measured by the measurement unit 121 is less than a predetermined number, the calculation unit 122 uses an assumed speed determined based on the number of vehicles measured by the measurement unit 121 and the speed of the vehicle. Thus, the average speed may be calculated. Specifically, when compared at the same speed, the smaller the number of vehicles measured, the lower the possibility that traffic congestion has occurred. Therefore, the calculation unit 122 measures the smaller the number of vehicles measured. The average speed is calculated by using a large assumed speed as the speed of the number of vehicles that is less than the predetermined number to be used. For example, when the number of vehicles measured by the measurement unit 121 is the first number (for example, four), the calculation unit 122 calculates an average speed using an estimated speed of 40 km / h as a traffic jam reference speed, and the measurement unit When the number of vehicles measured by 121 is a second number (for example, two) that is smaller than the first number, the average speed is calculated with the speed limit of 80 km per hour as an assumed speed.

[Use information from other imaging apparatus 100]
FIG. 7 is a diagram illustrating another configuration example of the imaging apparatus 100 according to the second embodiment. The imaging apparatus 100 shown in FIG. 7 is different from the imaging apparatus 100 shown in FIG. 4 in that it further includes an acquisition unit 124, and is the same in other respects.

  The acquisition unit 124 acquires information from the imaging device 100 disposed upstream of the traffic flow. For example, the acquisition unit 124 acquires information indicating the average speed of the vehicle calculated by the calculation unit 122 in the photographing apparatus 100 arranged upstream within a predetermined period. When the number of vehicles measured by the measurement unit 121 is less than the predetermined number, the calculation unit 122 assumes the estimated speed determined based on the number of vehicles measured by the measurement unit 121 and the information acquired by the acquisition unit 124. Is used to calculate the average speed. The acquisition unit 124 acquires information indicating the average speed from the imaging device 100 arranged upstream for each measurement period in which the measurement unit 121 measures the number of vehicles, and the calculation unit 122 acquires in each measurement period. The average speed may be calculated based on the average speed information.

  As described above, according to the photographing apparatus 100 according to the second embodiment, the occurrence of traffic congestion can be achieved by measuring a short time by a simple average speed calculation process without using the table indicating the inter-vehicle distance as shown in FIG. There exists an effect that the presence or absence of can be determined.

<Third Embodiment>
[Change measurement period]
FIG. 8 is a diagram illustrating a configuration example of the imaging apparatus 100 according to the third embodiment. The imaging apparatus 100 illustrated in FIG. 8 is different from the imaging apparatus 100 illustrated in FIG. 4 in that the measurement period determination unit 125 is included, and is the same in other points. The measurement period determination unit 125 determines the measurement period based on the speed of the vehicle that has been photographed earliest calculated by the calculation unit 122.

  As can be seen from the table shown in FIG. 6, when the vehicle is traveling at regular intervals, the slower the speed, the more the traffic jam occurs even when a smaller number is detected. It can be determined that there is a possibility. For example, when the speed is 40 km / h, the inter-vehicle distance is 20 m or less when five or more vehicles are shown in the image within the measurement time of 10 seconds, whereas the speed is 20 km / h. In some cases, the inter-vehicle distance is 20 m or less when three or more vehicles are shown in the image within the same measurement time. Therefore, when the speed of the vehicle is relatively slow, the imaging device 100 can determine that there is a possibility that a traffic jam has occurred based on the speed of a smaller number of vehicles than when the speed of the vehicle is high. it can.

  Therefore, the measurement period determination unit 125 determines the measurement period to be longer as the speed of the vehicle photographed earliest in the measurement period is larger, and determines the measurement period to be shorter as the vehicle speed is smaller. When the measurement period determining unit 125 determines the measurement period in this way, the photographing apparatus 100 determines that the traffic jam has occurred in a short time when the vehicle speed is low and the traffic jam is likely to occur. Can do.

<Fourth Embodiment>
[Determine based on accumulated speed information]
FIG. 9 is a diagram illustrating a configuration example of the imaging apparatus 100 according to the fourth embodiment. The imaging apparatus 100 illustrated in FIG. 9 is different from the imaging apparatus 100 illustrated in FIG. 8 in that it includes a storage control unit 126, an average speed calculation unit 127, an inter-vehicle distance calculation unit 128, and a storage unit 140. It is.

  In the present embodiment, the calculation unit 122 continuously calculates the speed of the vehicle without being limited to a predetermined measurement period. The storage control unit 126 associates the time at which the vehicle was photographed by the photographing unit 110 with the speed of the vehicle calculated by the calculation unit 122 and accumulates and stores it in the storage unit 140 as measurement information.

  Based on a plurality of pieces of measurement information stored in the storage unit 140, the average speed calculation unit 127 calculates the average speed of the vehicle imaged by the imaging unit 110 within the measurement period. The inter-vehicle distance calculation unit 128 calculates the average inter-vehicle distance of the vehicles photographed by the photographing unit 110 within the measurement period based on the plurality of measurement information stored in the storage unit 140. The inter-vehicle distance calculation unit 128 determines the distance between the two vehicles based on the time when the two vehicles are photographed at a predetermined position (for example, the central portion of the photographing region of the photographing unit 110) and the speed of the two vehicles. The distance is calculated, and the average value of the calculated inter-vehicle distance is calculated as the average inter-vehicle distance.

  The average speed calculation unit 127 and the inter-vehicle distance calculation unit 128 calculate the average speed and the average inter-vehicle distance using the measurement information corresponding to the measurement period determined by the measurement period determination unit 125. For example, the measurement period determining unit 125 determines a measurement period used for calculating the average speed based on at least a part of the plurality of pieces of measurement information stored in the storage unit 140. The average speed calculation unit 127 compares the speed of each vehicle with the reference speed in the order of the time when the vehicles were photographed. When the average speed calculation unit 127 detects a speed less than the predetermined reference speed, the average speed calculation unit 127 captures the image from the time when the vehicle that detected the speed was captured until the measurement period determined based on the detected speed elapses. The selected vehicle is selected, and the average speed of the selected vehicle is calculated.

  The output unit 123 outputs alarm information when the average speed is less than the reference speed and the average inter-vehicle distance is less than the predetermined distance. As described above, according to the imaging device 100 according to the present embodiment, the occurrence of traffic jam can be determined using the measurement information accumulated in the storage unit 140. Therefore, the imaging device 100 is captured by the imaging unit 110. Images need not be processed in real time. Therefore, according to the present embodiment, when the photographing apparatus 100 performs a process other than the detection of a traffic jam, it is possible to determine whether or not a traffic jam has occurred without affecting the other processes. Play.

<Fifth Embodiment>
[Determine how many units to measure the speed based on the measured speed]
FIG. 10 is a diagram illustrating a configuration example of the imaging apparatus 100 according to the fifth embodiment. The imaging apparatus 100 shown in FIG. 10 is different from the imaging apparatus 100 shown in FIG. 4 in that it has a determination unit 129, and is the same in other respects.

  When determining whether or not a traffic jam has occurred based on the vehicle speed calculated by the calculation unit 122, the determination accuracy can be increased by using as many vehicle speeds as possible. However, it may take a long time to determine that many vehicles are being monitored when the vehicle speed is low.

  Here, as is apparent from the example shown in FIG. 6, when the speed of the vehicle is small, the photographing apparatus 100 only measures the speed of a small number of vehicles compared to the case where the speed of the vehicle is large. It can be determined that there is a traffic jam. Therefore, the determination unit 129 determines the number of vehicles whose speed is to be measured based on the speed of the vehicle that has been photographed earliest after the start of the measurement calculated by the calculation unit 122. The calculation unit 122 calculates the average speed of the number of vehicles determined by the determination unit, and the output unit 123 outputs alarm information when the average speed is less than a predetermined reference speed.

  As described above, according to the photographing apparatus 100 according to the present embodiment, the photographing apparatus 100 determines the number of vehicles whose speed is to be measured based on the speed of the vehicle that has been photographed earliest. When it is relatively slow, there is an effect that it is possible to promptly determine the occurrence of traffic jam based on the speed of a relatively small number of vehicles.

<Sixth Embodiment>
[Operation example of the traffic jam determination system 10]
In the above embodiment, the image capturing apparatus 100 determines whether or not there is a possibility that a traffic jam has occurred. However, by determining whether or not there is a traffic jam in the data processing apparatus 200 that is connected to at least one of the plurality of imaging apparatuses 100 via a communication line and processes data received from the plurality of imaging apparatuses 100, the accuracy can be further increased. It is possible to make a high determination.

  When outputting the alarm information, the output units 123 of the plurality of imaging devices 100 output the alarm information in association with the identification information of the imaging device 100. The data processing device 200 includes a traffic jam determination unit (not shown) that determines whether or not traffic jam has occurred when alarm information is acquired from any of the plurality of imaging devices 100. The traffic jam determination unit is, for example, a microprocessor that operates by executing a program stored in a storage medium.

  The traffic jam determination unit starts determining whether or not there is a possibility of traffic jam in response to receiving alarm information from at least one vehicle. The traffic jam determination unit can determine the traffic jam range based on the alarm information output from the imaging device 100 upstream of the imaging device 100 that output the first acquired alarm information. The traffic jam determination unit may determine the traffic jam range further based on the alarm information output from the imaging device 100 downstream of the imaging device 100 that output the first acquired alarm information.

  The traffic jam determination unit is configured to check whether or not the traffic jam is detected in the video camera 100 when alarm information is not received from the video camera 100 arranged between the multiple camera 100 that transmitted the alarm information. A confirmation message may be sent. The traffic jam determination unit may determine the traffic jam range based on the response content to the confirmation message.

  In the above embodiment, the image capturing apparatus 100 and the data processing apparatus 200 are described as apparatuses having different configurations. However, even if the image capturing apparatus 100 includes the configuration of the data processing apparatus 200 and one of the plurality of image capturing apparatuses 100 functions as the data processing 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 ... Traffic jam determination system, 50 ... Communication line, 100 ... Image pick-up device, 110 ... Image pick-up part, 120 ... Control part, 121 ... Measuring part, 122 ... Calculation part, 123: Output unit, 124 ... Acquisition unit, 125 ... Measurement period determination unit, 126 ... Storage control unit, 127 ... Average speed calculation unit, 128 ... Inter-vehicle distance calculation unit, 129 ... Determining unit, 140 ... Storage unit, 200 ... Data processing device, 300 ... Hub, 400 ... Monitor, 500 ... Tunnel

Claims (10)

An imaging unit for imaging a predetermined area;
A measuring unit for measuring the number of vehicles photographed by the photographing unit within a predetermined measurement period;
A calculation unit that calculates at least one of the speeds of the vehicles photographed by the photographing unit within the measurement period;
When the number of units measured by the measuring unit is equal to or greater than a predetermined number, when the speed calculated by the calculating unit is less than a predetermined reference speed, alarm information indicating a possibility that a traffic jam has occurred is output. An output section;
An imaging device comprising: The calculating unit calculates the speed of at least the predetermined number of vehicles when the number of the vehicles measured by the measuring unit is equal to or greater than the predetermined number;
The output unit outputs the alarm information when at least one of the calculated speeds is less than the reference speed;
The imaging device according to claim 1. The calculation unit includes:
When the number of vehicles measured by the measurement unit is equal to or greater than the predetermined number, the speed of at least the predetermined number of vehicles is calculated, and an average of the vehicles photographed by the photographing unit based on the calculated speed Calculate the speed,
When the number of vehicles measured by the measuring unit is less than the predetermined number, the speed of all vehicles photographed by the photographing unit is calculated, and the number of vehicles photographed is subtracted from the predetermined number. Assuming that the obtained number of vehicles were traveling at a predetermined assumed speed, based on the speed of the vehicle photographed by the photographing unit and the assumed speed of the number of vehicles obtained by the subtraction, Calculate the average speed of the vehicle photographed by the photographing unit,
The output unit outputs the alarm information when the average speed calculated by the calculation unit is less than a predetermined reference speed;
The imaging device according to claim 1. The calculation unit, when the number of vehicles measured by the measurement unit is less than the predetermined number, the assumption determined based on the number of vehicles measured by the measurement unit and the speed of the vehicle Calculating the average speed using speed,
The imaging device according to claim 3. The imaging device includes an acquisition unit that acquires information from an imaging device arranged upstream of a traffic flow,
The calculation unit is determined based on the number of vehicles measured by the measurement unit and the information acquired by the acquisition unit when the number of vehicles measured by the measurement unit is less than the predetermined number. The average speed is calculated using the assumed speed.
The imaging device according to claim 4. A measurement period determining unit configured to change the measurement period based on the speed of the vehicle that has been photographed earliest calculated by the calculation unit;
The imaging device according to any one of claims 1 to 5. The measurement unit periodically measures the number of vehicles photographed within the measurement period,
The output unit outputs the alarm information when the speed of the vehicle photographed within the measurement period is less than the reference speed in any of a plurality of consecutive measurement periods.
The imaging device according to any one of claims 1 to 6. A storage control unit that associates the time at which the vehicle was imaged by the imaging unit with the speed of the vehicle calculated by the calculation unit, and accumulates and stores the measurement information in the storage unit;
Based on a plurality of pieces of measurement information stored in the storage unit, an average speed calculation unit that calculates an average speed of a vehicle imaged by the imaging unit during the measurement period;
An inter-vehicle distance calculation unit that calculates an average inter-vehicle distance of a vehicle photographed by the photographing unit within the measurement period based on a plurality of measurement information stored in the storage unit;
The output unit further outputs the alarm information when the average inter-vehicle distance is less than a predetermined distance when the average speed is less than the reference speed.
The imaging device according to any one of claims 1 to 6. An imaging unit for imaging a predetermined area;
A measuring unit for measuring the number of vehicles photographed by the photographing unit;
A calculation unit for calculating the speed of the vehicle imaged by the imaging unit;
A number determination unit for determining the number of vehicles whose speed is to be measured based on the speed of the vehicle photographed earliest calculated by the calculation unit;
An output unit that outputs alarm information based on the speed calculated by the calculation unit;
With
The calculation unit calculates an average speed of the vehicles of the number determined by the determination unit,
The said output part is an imaging device which outputs the said alarm information, when the said average speed is less than the predetermined reference speed. A plurality of imaging apparatuses according to any one of claims 1 to 9, a data processing apparatus connected to at least one of the plurality of imaging apparatuses via a communication line, and processing data received from the plurality of imaging apparatuses; With
The output unit of the plurality of imaging devices outputs the alarm information in association with identification information of the imaging device,
The data processing device includes:
A traffic jam determination system comprising a traffic jam judgment unit that judges whether or not traffic jam has occurred when the alarm information is acquired from any of the plurality of imaging devices.

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