JP2021117678A - Traffic state detection device, traffic state detection method and program - Google Patents

Abstract

To solve the problem that it is desired to provide a technique capable of measuring a vehicle speed in a simple configuration without the need to give information relating to a traffic flow state at a target spot from the outside while suppressing required cost.SOLUTION: Provided is a traffic state detection device comprising: a traffic volume calculation unit which acquires from a vehicle detection unit a detection result of a vehicle that travels at a predetermined position on a road, and calculates a traffic volume corresponding to the predetermined position; a statistic information analysis unit which determines whether a traffic flow state on the road is a congestion flow or a free flow on the basis of statistic information relating to vehicle traveling on the road and obtains a determination result of the traffic flow state; and a speed determination unit which determines a vehicle speed corresponding to the predetermined position on the basis of the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position and a correspondence of a prepared traffic volume and the vehicle speed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a traffic condition detection device, a traffic condition detection method and a program.

In recent years, various methods have been known as methods for calculating the speed of a vehicle traveling on a road. For example, there is known a technique of calculating a vehicle speed based on a traffic volume measured by a traffic counter that measures the number of vehicles traveling on a road (traffic volume). Traffic counter technologies include technology that measures traffic volume based on data detected by sensors buried under the road, and traffic based on images taken by a camera mounted above the road. There is also a technique for measuring quantity.

In addition, a technique is disclosed in which an on-board unit mounted on a vehicle measures the current vehicle speed and outputs a warning when the current vehicle speed exceeds a threshold value (see, for example, Patent Document 1). Further, a technique for calculating a vehicle speed based on a change in the reception intensity of a signal transmitted from an access point in an in-vehicle device is disclosed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2014-67155 Japanese Unexamined Patent Publication No. 2006-39762

However, in the technology of measuring traffic volume using a sensor buried under the road, when the sensor breaks down, it is necessary to dig up the sensor from under the ground and then check the sensor. There are many costs to maintain (monetary and human costs). That is, the technology for measuring the traffic volume using the sensor buried under the road requires a lot of cost for measuring the vehicle speed.

Further, the technique described in Patent Document 1 requires an on-board unit capable of measuring the vehicle speed, so that the vehicle speed cannot be measured with a simple configuration. For example, until the spread of in-vehicle devices capable of measuring vehicle speed, the number of vehicles capable of measuring speed will not increase easily.

Further, in the technique described in Patent Document 2, in order to investigate the change in the reception strength of the signal transmitted from the access point in the vehicle-mounted device, it is necessary for the vehicle-mounted device and the access point to communicate with each other in a short cycle. The vehicle speed cannot be measured with a simple configuration. Further, in the technique described in Patent Document 2, since the configuration for measuring the reception strength of the signal transmitted from the access point must be incorporated in the on-board unit, the vehicle speed cannot be measured with a simple configuration.

Also, in general, even if you try to calculate the vehicle speed from the traffic volume, if the traffic volume is less than a certain level, is it whether a small number of vehicles are traveling at high speed or a large number of vehicles are traveling at low speed? Can be difficult to distinguish. That is, it may be difficult to distinguish whether the traffic flow state at the target point is "free flow" or "congested flow". Therefore, in general, when trying to calculate the vehicle speed from the traffic volume, it is necessary to provide the system with information on the traffic flow state at the target point from the outside. However, information on the traffic flow condition at the target point is not always easily available from the outside.

Therefore, it is desired to provide a technique capable of measuring the vehicle speed with a simple configuration without having to give information on the traffic flow state at the target point from the outside while suppressing the necessary cost.

In order to solve the above problem, according to a certain viewpoint of the present invention, the detection result of a vehicle traveling at a predetermined position on the road is acquired from the vehicle detection unit, and based on the detection result of the vehicle, the vehicle is moved to the predetermined position. Based on the traffic volume calculation unit that calculates the corresponding traffic volume and statistical information on vehicle running on the road, it is determined whether the traffic flow state on the road is a congested flow or a free flow, and the traffic flow. Based on the statistical information analysis unit that obtains the judgment result of the state, the judgment result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance. Provided is a traffic condition detection device including a speed determination unit for determining a vehicle speed corresponding to a predetermined position.

The statistical information includes information on a time-series change in traffic volume, and the statistical information analysis unit is free to decide whether the traffic flow state on the road is a congested flow based on the information on the time-series change in traffic volume. It may be determined whether it is a flow.

When the traffic volume decreases from a predetermined upper limit traffic volume or more to a predetermined lower limit traffic volume or less within a predetermined time, the statistical information analysis unit changes the traffic flow state corresponding to the predetermined position to a congested flow. May be determined.

When the traffic volume increases to a predetermined upper limit traffic volume or more, the statistical information analysis unit may determine that the traffic flow state corresponding to the predetermined position has changed to a congested flow.

When the traffic volume decreases to a predetermined lower limit traffic volume or less, the statistical information analysis unit may determine that the traffic flow state corresponding to the predetermined position has changed to a free flow.

The statistical information includes information on a vehicle passing time interval, and the statistical information analysis unit determines whether the traffic flow condition on the road is a congested flow or a free flow based on the information on the vehicle passing time interval. May be determined.

When the fitting degree between the distribution of the vehicle passing time interval and the predetermined distribution exceeds the threshold value, the statistical information analysis unit determines that the traffic flow state is a free flow, and the fitting degree sets the threshold value. If it is lower than that, it may be determined that the traffic flow state is a congested flow.

The traffic state detection device determines whether the traffic flow state on the road is a congested flow or a free flow based on the detection time difference of the same vehicle by a plurality of vehicle detection units, and determines whether the traffic flow state is a congested flow or a free flow. A required time determination unit for obtaining a determination result is provided, and the speed determination unit corresponds to the predetermined position based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship. The vehicle speed may be determined.

The required time determination unit determines that the traffic flow state is a congested flow when the detection time difference exceeds the predetermined time difference, and when the detection time difference is less than the predetermined time difference. May determine that the traffic flow state is a free flow.

The traffic state detection device includes a correspondence relationship creation unit that creates the correspondence relationship based on the traffic volume calculated in advance by the traffic volume calculation unit and the vehicle speed acquired in advance by the vehicle speed acquisition unit. May be good.

The correspondence creation unit is a vehicle speed of a predetermined speed or less, or a vehicle of a predetermined speed or less that continues beyond a predetermined duration within the vehicle speed of a predetermined period acquired by the vehicle speed acquisition unit. If the speed is not included, the traffic volume and vehicle speed for the predetermined period may be excluded from the data for creating the correspondence.

The vehicle speed acquisition unit may include a probe antenna.

The vehicle detection unit may detect the vehicle in real time.

The vehicle detection unit may include a free flow antenna.

Further, according to another aspect of the present invention, the detection result of the vehicle traveling at the predetermined position on the road is acquired from the vehicle detection unit, and the traffic volume corresponding to the predetermined position is calculated based on the detection result of the vehicle. Based on the calculation and statistical information on vehicle running on the road, it is determined whether the traffic flow state on the road is a congested flow or a free flow, and the determination result of the traffic flow state is obtained. , The vehicle speed corresponding to the predetermined position is determined based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance. And, including, traffic condition detection methods are provided.

Further, according to another aspect of the present invention, the computer acquires the detection result of the vehicle traveling at the predetermined position on the road from the vehicle detection unit, and corresponds to the predetermined position based on the detection result of the vehicle. Based on the traffic volume calculation unit that calculates the traffic volume and statistical information on vehicle running on the road, it is determined whether the traffic flow state on the road is a congested flow or a free flow, and the traffic flow state is determined. Based on the statistical information analysis unit that obtains the determination result, the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance, the predetermined position A program for functioning as a traffic condition detection device including a speed determination unit for determining a vehicle speed corresponding to the above is provided.

As described above, according to the present invention, there is a technique that makes it possible to measure the vehicle speed with a simple configuration without having to provide information on the traffic flow state at the target point from the outside while suppressing the necessary cost. Provided.

It is a figure which shows the functional structure example of the traffic state detection apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the example of free flow data. It is a figure which shows the example of the probe data. It is a figure which shows the example of the QV diagram. It is a line graph which shows an example of the time series change of the traffic volume. It is a bar graph which shows an example of the frequency distribution of the vehicle passing time interval when the traffic flow state is a free flow. It is a bar graph which shows an example of the frequency distribution of the vehicle passing time interval when the traffic flow state is a congested flow. It is a flowchart which shows the example of the traffic volume calculation processing executed by the traffic state detection device which concerns on the same embodiment. It is a flowchart which shows the example of the QV diagram creation process executed by the traffic state detection apparatus which concerns on this embodiment. It is a flowchart which shows the example of the speed calculation process executed by the traffic state detection apparatus which concerns on the same embodiment. It is a figure which shows the functional structure example of the traffic state detection apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the example of the speed calculation process executed by the traffic state detection apparatus which concerns on the same embodiment. It is a figure which shows the hardware composition of the information processing apparatus as an example of the traffic state detection apparatus which concerns on 1st Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

Further, in the present specification and the drawings, a plurality of components having substantially the same functional configuration may be distinguished by adding different numbers after the same reference numerals. However, if it is not necessary to distinguish each of a plurality of components having substantially the same functional configuration, only the same reference numerals are given. Further, similar components of different embodiments may be distinguished by adding different alphabets after the same reference numerals. However, if it is not necessary to distinguish each of the similar components of different embodiments, only the same reference numerals are given.

(1. Details of the first embodiment)
First, the details of the first embodiment of the present invention will be described.

(1-1. Configuration of traffic condition detection device)
First, a configuration example of the traffic state detection device 1 according to the first embodiment of the present invention will be described. FIG. 1 is a diagram showing a functional configuration example of the traffic state detection device 1 according to the first embodiment of the present invention.

With reference to FIG. 1, vehicles M1 to M3 are shown as examples of vehicles traveling on the road. Further, referring to FIG. 1, the vehicle M1 and the vehicle M2 are traveling in the back lane (the vehicle M1 is traveling following the vehicle M2), and the front lane is the back lane. The vehicle M3 is traveling in the opposite direction to the vehicle M1 and the vehicle M2. As described above, in the embodiment of the present invention, it is mainly assumed that the road is composed of a plurality of lanes, but the road may be composed of one lane.

The traffic state detection device 1 according to the first embodiment of the present invention includes a probe data storage unit 121, a free flow data storage unit 122, a QV diagram storage unit 123, a QV diagram creation unit 130, and a traffic volume calculation unit. It includes 140 and a speed calculation unit 150. A probe antenna 112 is connected to the probe data storage unit 121, and a free flow antenna 114 is connected to the free flow data storage unit 122.

The QV diagram creating unit 130, the traffic volume calculation unit 140, and the speed calculation unit 150 include an arithmetic unit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and are stored in a ROM (Read Only Memory). The function can be realized by expanding the program into RAM by an arithmetic unit and executing it. At this time, a computer-readable recording medium on which the program is recorded may also be provided.

Alternatively, the QV diagram creating unit 130, the traffic volume calculation unit 140, and the speed calculation unit 150 may be configured by dedicated hardware, or may be configured by a combination of a plurality of hardware. The data required for the calculation by the arithmetic unit is appropriately stored by a storage unit (not shown).

The probe data storage unit 121, the free flow data storage unit 122, and the QV diagram storage unit 123 are stored by a storage unit (not shown). Such a storage unit may be composed of a memory such as a RAM (Random Access Memory), a hard disk drive, or a flash memory.

(Free flow antenna 114)
The free-flow antenna 114 functions as an example of a vehicle detection unit that detects a vehicle traveling at a predetermined position on the road. That is, in the embodiment of the present invention, it is mainly assumed that the vehicle detection unit includes the free flow antenna 114. As a result, the ETC free-flow antenna of the ETC (Electronic Toll Collection) system already constructed can be used as the vehicle detection unit, so that it is not necessary to newly provide the vehicle detection unit. However, instead of the free-flow antenna 114, another vehicle detection unit (for example, an infrared sensor or an ultrasonic sensor) may be used.

More specifically, the free-flow antenna 114 detects the vehicle in real time by receiving vehicle identification information (vehicle ID) from the vehicle through communication with the vehicle-mounted device mounted on the vehicle. In the embodiment of the present invention, it is mainly assumed that an ETC on-board unit is used as an example of the on-board unit. It is assumed that the free-flow antenna 114 is compatible with a plurality of versions of the ETC on-board unit, while the probe antenna 112 described later may be compatible only with a specific version of the ETC on-board unit. is assumed. That is, the free-flow antenna 114 can detect more vehicles than the probe antenna 112.

The "predetermined position" on the road is not particularly limited as long as it is the position of the vehicle that can be detected by the vehicle detection unit. In the following, the position (predetermined position) of the vehicle that can be detected by the free-flow antenna 114 may be simply referred to as "in front of the free-flow antenna". However, the position of the vehicle that can be detected by the free-flow antenna 114 may be a position deviated from the front of the free-flow antenna.

More specifically, when the free flow antenna 114 detects the vehicle in real time by receiving the vehicle ID by communicating with the on-board unit mounted on the vehicle, the vehicle detection result (hereinafter, also referred to as "free flow data"). ) Is output to the free flow data storage unit 122 in real time. Then, the vehicle detection result output from the free flow antenna 114 to the free flow data storage unit 122 in real time can be used in real time by the traffic volume calculation unit 140 and the speed calculation unit 150.

Here, "real time" can mean any timing of a short period of time from the arrival of the vehicle in front of the free flow antenna to the change in the traffic condition on the road. If the vehicle is detected at this timing, some measures may be taken according to the traffic condition at the time when the vehicle is detected before the traffic condition on the road changes.

FIG. 2 is a diagram showing an example of free flow data. As shown in FIG. 2, the free flow data is associated with a “vehicle ID” and a “passing time”. The "vehicle ID" is vehicle identification information received from the vehicle by communication between the free-flow antenna 114 and the vehicle-mounted device mounted on the vehicle. The "passing time" is the time when the vehicle ID is received from the vehicle by the free flow antenna 114, and may correspond to the time when the vehicle passes in front of the free flow antenna.

(Probe antenna 112)
The probe antenna 112 functions as an example of a vehicle speed acquisition unit that acquires the vehicle speed. That is, in the embodiment of the present invention, it is mainly assumed that the vehicle speed acquisition unit includes the probe antenna 112. As a result, the ETC probe antenna of the ETC system already constructed can be used as the vehicle speed acquisition unit, so that it is not necessary to newly provide the vehicle speed acquisition unit. However, instead of the probe antenna 112, another vehicle speed acquisition unit may be used.

More specifically, when the probe antenna 112 acquires the vehicle speed from the vehicle by communication with the vehicle-mounted device mounted on the vehicle, the probe antenna 112 outputs the acquired vehicle speed to the probe data storage unit 121. Then, the vehicle speed output from the probe antenna 112 to the probe data storage unit 121 can be used by the QV diagram creating unit 130.

FIG. 3 is a diagram showing an example of probe data. As shown in FIG. 3, the probe data is associated with the “passing time”, the “kilometer post”, the “vehicle speed”, and the “collection time”. The "passing time" is the time when the vehicle passes the distance marker (kilopost) from the starting point of the road. "Kilopost" is a distance marker from the starting point of the road. The "vehicle speed" is the speed (for example, average speed) of a vehicle passing in front of a distance marker (kilopost) from the starting point of a road. The "collection time" is the time when the vehicle speed is collected by the probe antenna 112.

(Traffic volume calculation unit 140)
The explanation will be continued by returning to FIG. The traffic volume calculation unit 140 acquires the detection result (free flow data) of the vehicle traveling in front of the free flow antenna from the free flow data storage unit 122 (FIG. 2). Then, based on the free flow data (vehicle ID and passing time), the traffic volume calculation unit 140 passes the number of vehicles passing in front of the free flow antenna per preset unit time (unit time by the free flow antenna 114). The number of vehicle IDs detected around) is calculated as the traffic volume in front of the free flow antenna. The calculation of the traffic volume by the traffic volume calculation unit 140 may be repeated every unit time.

Not all vehicles that have passed in front of the free-flow antenna are equipped with an on-board unit capable of communicating with the free-flow antenna 114. That is, not all vehicles that have passed in front of the free flow antenna are detected by the free flow antenna 114. Therefore, the ratio of vehicles equipped with an on-board unit capable of communicating with the free-flow antenna 114 to the entire vehicle (including vehicles not equipped with an on-board unit capable of communicating with the free-flow antenna 114) is defined as "on-board unit mounting ratio". When the number of vehicles detected by the free-flow antenna 114 is set as the "number of detected vehicles", the traffic volume calculation unit 140 increases the traffic volume in front of the free-flow antenna by the equation (1). It is desirable to estimate with accuracy.

(Estimated value of traffic volume) = (Number of detected vehicles) ÷ (Ratio of on-board equipment installed) ... (1)

However, such estimation may be omitted when the on-board unit capable of communicating with the free flow antenna 114 is sufficiently widespread. The traffic volume estimated by the traffic volume calculation unit 140 is output to the speed calculation unit 150 each time it is estimated. Further, the traffic volume estimated by the traffic volume calculation unit 140 and the unit time corresponding to the traffic volume are output to the QV diagram creating unit 130 for each predetermined period for a predetermined period.

Typically, the predetermined period may be one day. In that case, the latest daily traffic volume may be output to the QV diagram creating unit 130 only once a day. However, the predetermined period is not limited to one day. For example, the predetermined period may be one month. Further, not only the latest traffic volume but also the past traffic volume (for example, the traffic volume for one day one year ago) may be output to the QV diagram creating unit 130.

(QV diagram creation unit 130)
When the QV diagram creating unit 130 acquires the traffic volume and the unit time for a predetermined period before the free flow antenna output from the traffic volume calculation unit 140, the probe data storage unit 121 corresponds to the free flow antenna corresponding to the predetermined period. Obtain the previous vehicle speed (ie, the vehicle speed corresponding to the "kilopost" at the freeflow antenna position) and the transit time. The QV diagram creating unit 130 determines the traffic volume and the vehicle speed based on the traffic volume and unit time for a predetermined period in front of the free flow antenna and the vehicle speed and passing time in front of the free flow antenna corresponding to the predetermined period. It functions as an example of the correspondence relationship creation unit that creates the correspondence relationship (approximate expression in the following example).

More specifically, the QV diagram creating unit 130 associates the traffic volume corresponding to the unit time with the vehicle speed corresponding to the passing time within the unit time. The QV diagram creating unit 130 associates the traffic volume with the vehicle speed for the entire unit time output from the traffic volume calculation unit 140, so that the traffic volume (Q) and the vehicle speed (V) correspond to each other. Create a diagram (QV diagram). The QV diagram creation unit 130 stores the created QV diagram in the QV diagram storage unit 123.

FIG. 4 is a diagram showing an example of a QV diagram. In the QV diagram shown in FIG. 4, the horizontal axis represents the traffic volume (Q) and the vertical axis represents the vehicle speed (V). In such a QV diagram, each result in which the traffic volume and the vehicle speed are associated is plotted as each point. Here, in the QV diagram, when the traffic volume is less than the predetermined traffic volume, even if the traffic volume is fixed to one, the traffic flow state corresponding to the traffic volume is (vehicle speed is higher than the boundary speed). Two types of traffic can be assumed: traffic flow (which is also low) and free flow (where the vehicle speed is higher than the boundary speed).

Therefore, the QV diagram creating unit 130 creates an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow as an example of the correspondence relationship between the traffic volume and the vehicle speed based on the QV diagram. The QV diagram creating unit 130 stores the approximate expression corresponding to the congested flow and the approximate expression corresponding to the free flow in the QV diagram storage unit 123. For example, the creation of an approximate expression corresponding to a congested flow and an approximate expression corresponding to a free flow can be learned by machine learning.

The approximate expression corresponding to the traffic congestion may be any expression, but as an example, it can be expressed by a quadratic function as shown in the following expression (2). However, in the formula (2), V is the vehicle speed and Q is the traffic volume. More specifically, in the QV diagram creating unit 130, the function expressed in the equation (2) is plotted at each point on the QV diagram (however, the region where the vehicle speed V is lower than the boundary speed (below the boundary line). By finding a and b so as to approximate all or part of the point)), an approximate expression corresponding to the congested flow is obtained.

V = aQ ² + b ... (2)

On the other hand, the approximate expression corresponding to the free flow may be any expression, but as an example, it can be expressed by a linear function as shown in the following equation (3). More specifically, in the QV diagram creating unit 130, the function expressed in the equation (3) is plotted at each point on the QV diagram (however, the region where the vehicle speed V is higher than the boundary speed (above the boundary line)). By finding c and d so as to approximate (all or part of the points), an approximate expression corresponding to the free flow is obtained.

V = cQ + d ... (3)

The shape of the QV diagram may differ depending on the route, the shape of the road, the number of lanes in which the vehicle travels, and the like. Therefore, it is desirable that a separate QV diagram is created for each location as described above, instead of a QV diagram that is common to all locations (it is desirable that a QV diagram corresponding to each free flow antenna is created separately). ). Further, as shown in FIG. 4, the vehicle speed in the case of the heaviest traffic volume (that is, the vehicle speed corresponding to the "maximum traffic volume") is generally uniquely determined by the boundary speed between the free flow and the congested flow.

Further, the traffic volume for a predetermined period before the free flow antenna and the vehicle speed before the free flow antenna corresponding to the predetermined period may not be used for creating the correspondence relationship between the traffic volume and the vehicle speed. .. For example, if there is no congested flow throughout a given period, it is assumed that a useful correspondence between traffic volume and vehicle speed cannot be obtained.

Therefore, the QV diagram creating unit 130 has a vehicle speed of a predetermined speed or less (for example, a vehicle speed of 40 km / h or less) or a predetermined duration (for example, several minutes) in the "vehicle speed" of the predetermined period. If the vehicle speed that continues beyond the specified speed is not included, the traffic volume and vehicle speed for the specified period will be used from the data for creating the correspondence between the traffic volume (Q) and the vehicle speed (V). May be excluded. This can create a more useful correspondence.

Further, as described above, the free-flow antenna 114 can collectively detect vehicles traveling in each of the plurality of lanes. Therefore, when a predetermined event (for example, road construction or accident) in which a vehicle can travel only in a part of a plurality of lanes occurs, the number of vehicles detected by the free flow antenna 114 decreases. Is assumed. Therefore, it is desirable that the QV diagram creating unit 130 creates a correspondence relationship between the traffic volume and the vehicle speed for each number of lanes in which the vehicle can travel. For example, it is desirable that the QV diagram creating unit 130 creates a correspondence relationship for the event occurrence when a predetermined event occurs in which the vehicle can travel only a part of the plurality of lanes.

(Statistical Information Analysis Department 160)
The explanation will be continued by returning to FIG. The statistical information analysis unit 160 determines whether the traffic flow condition on the road is a congested flow or a free flow based on the statistical information regarding the vehicle traveling on the road. As a result, the statistical information analysis unit 160 obtains the determination result of the traffic flow state. Here, examples of statistical information include time-series changes in traffic volume and vehicle passing time intervals. In the following, the statistical information analysis unit 160 includes a traffic volume time-series change determination unit 151 and a vehicle passage interval determination unit 152, and the traffic volume time-series change determination unit 151 provides a traffic flow state based on a time-series change in traffic volume. Is determined, and it is assumed that the vehicle passage interval determination unit 152 determines the traffic flow state based on the vehicle passage time interval.

Then, when both the traffic volume time-series change determination unit 151 and the vehicle passage interval determination unit 152 determine that the traffic flow state is a congested flow, the speed calculation unit 150 determines that the traffic flow state is a congested flow. It is assumed that it will be done. On the other hand, when at least one of the traffic volume time series change determination unit 151 and the vehicle passage interval determination unit 152 determines that the traffic flow state is free flow, the speed calculation unit 150 determines that the traffic flow state is free flow. It is mainly assumed that there is a case.

However, the traffic flow state determined by the traffic volume time series change determination unit 151 may be used as it is by the speed determination unit 156. Alternatively, the traffic flow state determined by the vehicle passing interval determination unit 152 may be used as it is by the speed determination unit 156.

(Traffic volume time series change determination unit 151)
The traffic volume time-series change determination unit 151 determines the traffic flow state as a congestion flow based on the information on the time-series change of the traffic volume (the number of vehicles passed per unit time) output in real time from the traffic volume calculation unit 140. It is judged whether it is a free flow or a free flow. Here, the time-series change of the traffic volume may be a time-series change of any time length, for example, the latest predetermined time-series length (for example, 15 minutes retroactively from the present). It may be a time-series change of degree). Hereinafter, the determination of the traffic flow state by the traffic volume time series change determination unit 151 will be described in detail with reference to FIG.

FIG. 5 is a line graph showing an example of time-series changes in traffic volume. In the line graph shown in FIG. 5, the horizontal axis represents the time and the vertical axis represents the traffic volume (Q). In such a line graph, the traffic volume for each time is plotted as each point of the line graph. As shown in FIG. 5, the “congestion determination traffic volume” and the “congestion determination traffic volume” are preset. "Congestion judgment traffic volume" corresponds to the example of the upper limit traffic volume. "Congestion judgment traffic volume" corresponds to the example of the lower limit traffic volume.

For example, the "congestion determination traffic volume" may be the traffic volume obtained by multiplying the "maximum traffic volume" in the QV diagram by a predetermined upper limit ratio (for example, 80%). Further, the "traffic jam determination traffic volume" may be a traffic volume obtained by multiplying the "maximum traffic volume" in the QV diagram by a predetermined lower limit ratio (for example, 60%).

Here, as shown in FIG. 5, when the traffic volume decreases from "congestion determination traffic volume" or more to "congestion determination traffic volume" or less within a predetermined time, "congestion extension" is performed in front of the free flow antenna. Is assumed to have occurred. Therefore, when the traffic volume decreases from "congestion determination traffic volume" or more to "congestion determination traffic volume" or less within a predetermined time, the traffic volume time-series change determination unit 151 changes the traffic flow state in front of the free flow antenna. It may be determined that the flow has changed to a traffic jam.

Alternatively, the traffic volume time-series change determination unit 151 may determine that the traffic flow state in front of the free flow antenna has changed to a congested flow when the traffic volume increases to the "congestion determination traffic volume" or more.

On the other hand, as shown in FIG. 5, when the traffic volume is reduced to the "traffic jam determination traffic volume" or less, it is assumed that "traffic jam elimination" has occurred before the free flow antenna. Therefore, when the traffic volume decreases to "congestion determination traffic volume" or less, the traffic volume time-series change determination unit 151 may determine that the traffic flow state in front of the free flow antenna has changed to free flow.

As with the QV diagram, the time-series change in traffic volume may differ depending on the route, road shape, number of lanes in which the vehicle travels, and the like. Therefore, it is desirable to create separate congestion judgment traffic volume and congestion judgment traffic volume for each place instead of the congestion judgment traffic volume and congestion judgment traffic volume common to all places (congestion judgment corresponding to each free flow antenna). It is desirable that the traffic volume and the congestion judgment traffic volume are created separately). For example, thresholds and statistical distributions can be learned by machine learning.

(Vehicle passing interval determination unit 152)
The vehicle passage interval determination unit 152 is a temporal interval between two vehicles that continuously pass in front of the free flow antenna based on the free flow data (vehicle ID and passage time) acquired from the free flow data storage unit 122. (Hereinafter, also referred to as "vehicle passing time interval"), a frequency distribution (information on the vehicle passing interval) is generated. Then, the vehicle passing interval determination unit 152 determines whether the traffic flow state is a congested flow or a free flow based on the generated frequency distribution of the vehicle passing time interval.

Here, the free flow data may be any time length of free flow data, but for example, the latest predetermined time length (for example, a length of about 15 minutes retroactively from the present). It may be free flow data. Hereinafter, the determination of the traffic flow state by the vehicle passing interval determination unit 152 will be described in detail with reference to FIG.

FIG. 6 is a bar graph showing an example of the frequency distribution of the vehicle passing time interval when the traffic flow state is a free flow. FIG. 7 is a bar graph showing an example of the frequency distribution of the vehicle passing time interval when the traffic flow state is a congested flow.

In the bar graphs shown in FIGS. 6 and 7, the horizontal axis indicates the vehicle passing time interval, and the vertical axis indicates the frequency. In such a bar graph, the frequency for each vehicle passing time interval is represented as a bar graph. In the examples shown in FIGS. 6 and 7, the vehicle passing time interval is increased by 2 seconds, but the length of the vehicle passing time interval is not limited. For example, the leftmost bar graph shows the frequency with which the vehicle passing time interval is greater than 0 seconds and less than 2 seconds.

Here, the occurrence time interval of randomly occurring events follows a statistically predetermined distribution. In the following, it is mainly assumed that the statistically predetermined distribution is an exponential distribution. When the traffic flow condition is free flow (Fig. 6), it is assumed that the vehicle passing in front of the free flow antenna also occurs almost randomly. Therefore, the distribution of the vehicle passing time interval and the "approximate curve" of the distribution ( It is expected that the degree of fitting with the exponential distribution) will increase.

Therefore, in the vehicle passing interval determination unit 152, when the degree of fitting between the distribution of the vehicle passing time interval and the "approximate curve (exponential distribution)" of the distribution exceeds the threshold value (FIG. 6), the traffic flow state is free flow. On the other hand, when the degree of fitting between the distribution of the vehicle passing time interval and the "approximate curve (exponential distribution)" of the distribution is less than the threshold value, the vehicle passing interval determination unit 152 may determine that the vehicle passes (FIG. 7). It may be determined that the traffic flow state is a congested flow. If the fitting degree and the threshold value match, it may be determined that the traffic flow state is a free flow, or it is determined that the traffic flow state is a congested flow. May be good.

As with the time-series change in traffic volume, the vehicle transit time interval may differ depending on the route, road shape, number of lanes in which the vehicle travels, and the like. Therefore, it is desirable to create separate thresholds and statistical distributions for each location rather than common thresholds and statistical distributions for all locations (thresholds and statistical distributions in front of each freeflow antenna are separate). It is desirable to be created). For example, thresholds and statistical distributions can be learned by machine learning.

(Speed determination unit 156)
The velocity determination unit 156 acquires an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow from the QV diagram storage unit 123.

When the speed determination unit 156 determines that the traffic flow state is a congested flow by the statistical information analysis unit 160, the speed determination unit 156 outputs the current traffic volume from the traffic volume calculation unit 140 from the approximate expression corresponding to the congested flow. The vehicle speed (congestion flow speed V_jam) corresponding to the above is acquired and used as the vehicle speed in front of the flow antenna. On the other hand, when the velocity determination unit 156 determines that the traffic flow state is free flow by the statistical information analysis unit 160, the current speed determination unit 156 outputs the current output from the traffic volume calculation unit 140 from the approximate expression corresponding to the free flow. The vehicle speed (free flow speed V_free) corresponding to the traffic volume is acquired and used as the vehicle speed in front of the flow antenna.

The configuration example of the traffic condition detection device 1 according to the first embodiment of the present invention has been described above.

(1-2. Operation of traffic condition detection device)
Subsequently, an operation example of the traffic state detection device 1 according to the first embodiment of the present invention will be described. Hereinafter, as an example of the operation of the traffic state detection device 1 according to the first embodiment of the present invention, the traffic volume calculation process, the QV diagram creation process, and the speed calculation process will be described in order.

(Traffic volume calculation processing)
FIG. 8 is a flowchart showing an example of a traffic volume calculation process executed by the traffic condition detection device 1 according to the first embodiment of the present invention. First, the free-flow antenna 114 detects the vehicle in real time by receiving the vehicle identification information (vehicle ID) from the vehicle through communication with the on-board unit mounted on the vehicle. The vehicle detection result (free flow data) is output to the free flow data storage unit 122 in real time.

The traffic volume calculation unit 140 acquires the detection result (free flow data) of the vehicle traveling in front of the free flow antenna from the free flow data storage unit 122 (FIG. 2) (S11). Then, the traffic volume calculation unit 140 frees the number of vehicles (number of detected vehicles) that have passed in front of the free flow antenna per preset unit time based on the free flow data (vehicle ID and passing time). Calculated as the traffic volume in front of the flow antenna (S12). The traffic volume calculation unit 140 estimates the traffic volume in front of the free-flow antenna based on the number of detected vehicles and the on-board unit mounting ratio (S13).

The traffic volume estimated by the traffic volume calculation unit 140 is output to the speed calculation unit 150 each time it is estimated. Further, the traffic volume estimated by the traffic volume calculation unit 140 and the unit time corresponding to the traffic volume are output to the QV diagram creating unit 130 for each predetermined period for a predetermined period.

(QV diagram creation process)
FIG. 9 is a flowchart showing an example of a QV diagram creating process executed by the traffic state detection device 1 according to the first embodiment of the present invention. First, when the QV diagram creating unit 130 acquires the traffic volume and the unit time for a predetermined period in front of the free flow antenna output from the traffic volume calculation unit 140, the probe data storage unit 121 corresponds to the free flow corresponding to the predetermined period. The vehicle speed in front of the flow antenna and the passing time are acquired (S21).

The QV diagram creating unit 130 associates the traffic volume corresponding to the unit time with the vehicle speed corresponding to the passing time within the unit time. The QV diagram creating unit 130 associates the traffic volume with the vehicle speed for the entire unit time output from the traffic volume calculation unit 140, so that the traffic volume (Q) and the vehicle speed (V) correspond to each other. A diagram (QV diagram) is created (S22). Then, the QV diagram creation unit 130 creates an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow based on the created QV diagram. The QV diagram creating unit 130 stores the approximate expression corresponding to the congested flow and the approximate expression corresponding to the free flow in the QV diagram storage unit 123 (S23).

(Speed calculation process)
FIG. 10 is a flowchart showing an example of speed calculation processing executed by the traffic state detection device 1 according to the first embodiment of the present invention. When the traffic flow state is determined by the statistical information analysis unit 160, the speed determination unit 156 acquires an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow from the QV diagram storage unit 123. The speed determination unit 156 acquires the vehicle speed (congestion flow speed V_jam) corresponding to the current traffic volume from the approximate expression corresponding to the congested flow, and corresponds to the current traffic volume from the approximate expression corresponding to the free flow. The vehicle speed (free flow speed V_free) is acquired (S31).

When the traffic flow time-series change determination unit 151 determines that the traffic flow state is free flow (“free flow in front of the free flow antenna” in S32), the speed determination unit 156 shifts the operation to S35. .. On the other hand, when the speed determination unit 156 determines that the front of the free flow antenna is being stretched or is being resolved by the traffic volume time series change determination unit 151 (in S32, "the traffic is being stretched in front of the free flow antenna". -Traffic jam is being resolved "), shift to S33.

Subsequently, when the speed determination unit 156 determines that the traffic flow state is free flow by the vehicle passage interval determination unit 152 (“free flow in front of the free flow antenna” in S33), the vehicle in front of the flow antenna Let the velocity be the free flow velocity V_free (S35). On the other hand, when the vehicle passage interval determination unit 152 determines that the traffic flow state is a congested flow (“congested flow before the free flow antenna” in S33), the speed determination unit 156 determines the vehicle speed in front of the flow antenna. Is the congestion flow speed V_jam (S34).

The operation example of the traffic state detection device 1 according to the first embodiment of the present invention has been described above.

(1-3. Effect)
As described above, according to the first embodiment of the present invention, the traffic volume can be measured by a predetermined vehicle detection unit without using the sensor buried under the road. Therefore, the sensor It is prevented that many costs (financial cost and human cost) are incurred to maintain the. That is, the cost for measuring the vehicle speed can be reduced. In particular, if the already constructed ETC free flow antenna is used as the vehicle detection unit, it is not necessary to newly provide the vehicle detection unit.

Similarly, according to the first embodiment of the present invention, the probe antenna 112 uses a vehicle speed acquisition unit that acquires the vehicle speed. In particular, if the already constructed ETC probe antenna is used as the vehicle speed acquisition unit, it is not necessary to newly provide the vehicle speed acquisition unit.

Further, according to the first embodiment of the present invention, an on-board unit capable of measuring the vehicle speed is required to create the QV diagram, but the vehicle speed is measured to calculate the vehicle speed. There is no need for an on-board unit that can. Therefore, according to the first embodiment of the present invention, the vehicle speed can be measured with a simple configuration. For example, it is possible to measure the speed of many vehicles even if the on-board unit capable of measuring the vehicle speed does not become widespread.

Further, according to the first embodiment of the present invention, it is not necessary for the vehicle-mounted device and the access point to communicate with each other in a short cycle in order to calculate the vehicle speed. Therefore, according to the first embodiment of the present invention, the vehicle speed can be measured with a simple configuration. Further, according to the first embodiment of the present invention, it is not necessary to incorporate a configuration for measuring the reception strength of the signal transmitted from the access point into the on-board unit, so that the vehicle speed can be measured with a simple configuration. ..

Further, according to the first embodiment of the present invention, it is possible to distinguish whether the traffic flow state at the target point is "free flow" or "congested flow" based on the statistical information. Therefore, according to the first embodiment of the present invention, it is possible to calculate the vehicle speed from the traffic volume without giving information on the traffic flow state of the target point to the system from the outside.

Further, according to the first embodiment of the present invention, the free flow antenna 114 can detect the vehicle in real time. That is, according to the first embodiment of the present invention, the vehicle speed is calculated based on the vehicle detection result obtained in real time by the free flow antenna 114, so that the vehicle speed can be calculated in real time. Although the vehicle speed can be obtained by the probe antenna 112, the vehicle speed cannot be obtained in real time by the probe antenna 112.

Further, since it is assumed that the free flow antenna 114 is compatible with a plurality of versions of the ETC on-board unit, according to the first embodiment of the present invention, it is based on the detection result of the vehicle by the free flow antenna 114. Therefore, more vehicle speeds can be calculated. On the other hand, since it is assumed that the probe antenna 112 is compatible only with a specific version of the ETC on-board unit, the probe antenna 112 can acquire a lower vehicle speed.

(2. Details of the second embodiment)
Subsequently, the details of the second embodiment of the present invention will be described.

(2-1. Configuration of traffic condition detection device)
First, a configuration example of the traffic condition detection device 2 according to the second embodiment of the present invention will be described. FIG. 11 is a diagram showing a functional configuration example of the traffic state detection device 2 according to the second embodiment of the present invention.

With reference to FIG. 11, the free flow antenna 116 located upstream of the free flow antenna 114 is shown. Like the free-flow antenna 114, the free-flow antenna 116 also corresponds to an example of the vehicle detection unit. That is, in the second embodiment of the present invention, a plurality of vehicle detection units are used. In addition, the traffic condition detection device 2 according to the second embodiment of the present invention requires a speed calculation unit 150 as compared with the traffic condition detection device 1 (FIG. 1) according to the first embodiment of the present invention. The main difference is that the determination unit 153 is provided. Therefore, in the following, the speed determination unit 156 that determines the vehicle speed based on the required time determination unit 153 and the required time determination unit 153 will be mainly described.

It is assumed that the same vehicle (more specifically, a vehicle equipped with an on-board unit that transmits the same vehicle ID) is detected by the free-flow antenna 114 and the free-flow antenna 116. In such a case, the required time determination unit 153 calculates the detection time difference of the same vehicle between the free flow antenna 114 and the free flow antenna 116. For example, the detection time difference can be calculated by calculating the difference between the passing times associated with the same vehicle ID based on the free flow data stored by the free flow data storage unit 122.

For example, when the detection time difference of the same vehicle exceeds a predetermined time difference set in advance, the required time determination unit 153 determines that the traffic flow state is a congested flow. On the other hand, when the detection time difference of the same vehicle is less than a predetermined time difference set in advance, the required time determination unit 153 determines that the traffic flow state is free flow. When the detection time difference and the predetermined time difference match, it may be determined that the traffic flow state is a free flow, or it may be determined that the traffic flow is a congested flow.

The velocity determination unit 156 acquires an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow from the QV diagram storage unit 123. Then, the speed determination unit 156 is based on the determination result of the traffic flow state determined by the required time determination unit 153, the traffic volume in front of the free flow antenna, and the correspondence relationship (approximate formula) between the traffic volume and the vehicle speed. Then, the vehicle speed in front of the free flow antenna is calculated.

Here, when the required time determination unit 153 determines that the traffic flow state is free flow, the speed determination unit keeps the determination result that the required time determination unit 153 indicates that the traffic flow state is free flow. It is mainly assumed that it is used by 156. Further, it is mainly assumed that the traffic flow state is determined by the statistical information analysis unit 160 when the required time determination unit 153 determines that the traffic flow state is a congested flow.

However, even when the required time determination unit 153 determines that the traffic flow state is a congested flow, the speed determination unit 156 keeps the determination result that the required time determination unit 153 indicates that the traffic flow state is a congested flow. It may be used. Alternatively, both the determination result of the traffic flow state by the required time determination unit 153 and the determination result of the traffic volume state by the statistical information analysis unit 160 may always be used.

As with the QV diagram, the predetermined time difference may differ depending on the route, the shape of the road, the number of lanes in which the vehicle travels, and the like. Therefore, it is desirable that a separate predetermined time difference is created for each location instead of a predetermined time difference that is common to all locations (it is desirable that a predetermined time difference corresponding to two free-flow antennas is created separately). .. For example, a predetermined time difference can be learned by machine learning.

The configuration example of the traffic condition detection device 2 according to the second embodiment of the present invention has been described above.

(2-2. Operation of traffic condition detection device)
Subsequently, an operation example of the traffic state detection device 2 according to the second embodiment of the present invention will be described. Hereinafter, the speed calculation process will be described as an example of the operation of the traffic state detection device 2 according to the second embodiment of the present invention.

(Speed calculation process)
FIG. 12 is a flowchart showing an example of speed calculation processing executed by the traffic state detection device 2 according to the second embodiment of the present invention. The velocity determination unit 156 acquires an approximate expression corresponding to the congested flow and an approximate expression corresponding to the free flow from the QV diagram storage unit 123. The speed determination unit 156 acquires the vehicle speed (congestion flow speed V_jam) corresponding to the current traffic volume from the approximate expression corresponding to the congested flow, and corresponds to the current traffic volume from the approximate expression corresponding to the free flow. The vehicle speed (free flow speed V_free) is acquired (S31).

The speed determination unit 156 determines the required time of the same vehicle from the free flow antenna 116 to the free flow antenna 114 by the required time determination unit 153, and determines that the traffic flow state is free flow based on the required time. In that case (“free flow in front of the free flow antenna” in S41), the operation shifts to S35. On the other hand, when the required time determination unit 153 determines that the traffic flow state is a congested flow (“there is a possibility that the free flow antenna is not in front of the free flow antenna” in S41), the speed determination unit 156 operates in S32. To migrate. S32 to S35 are carried out in the same manner as in the first embodiment of the present invention.

The operation example of the traffic state detection device 2 according to the second embodiment of the present invention has been described above.

(2-3. Effect)
As described above, according to the second embodiment of the present invention, the same effect as that of the first embodiment of the present invention can be obtained. Further, according to the second embodiment of the present invention, it is determined whether the traffic flow state is a free flow or a congested flow based on the required time of the same vehicle from the free flow antenna 116 to the free flow antenna 114. Therefore, the traffic flow state can be determined with higher accuracy.

(3. Hardware configuration example)
Subsequently, a hardware configuration example of the traffic state detection device 1 according to the first embodiment of the present invention will be described. However, a hardware configuration example of the traffic state detection device 2 according to the second embodiment of the present invention can be realized in the same manner.

Hereinafter, as a hardware configuration example of the traffic state detection device 1 according to the first embodiment of the present invention, a hardware configuration example of the information processing device 900 will be described. The hardware configuration example of the information processing device 900 described below is only an example of the hardware configuration of the traffic state detection device 1. Therefore, as for the hardware configuration of the traffic state detection device 1, an unnecessary configuration may be deleted from the hardware configuration of the information processing device 900 described below, or a new configuration may be added.

FIG. 13 is a diagram showing a hardware configuration of an information processing device 900 as an example of the traffic state detection device 1 according to the first embodiment of the present invention. The information processing device 900 includes a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, a RAM (Random Access Memory) 903, a host bus 904, a bridge 905, an external bus 906, and an interface 907. , An input device 908, an output device 909, a storage device 910, and a communication device 911.

The CPU 901 functions as an arithmetic processing device and a control device, and controls the overall operation in the information processing device 900 according to various programs. Further, the CPU 901 may be a microprocessor. The ROM 902 stores programs, calculation parameters, and the like used by the CPU 901. The RAM 903 temporarily stores a program used in the execution of the CPU 901, parameters that are appropriately changed in the execution, and the like. These are connected to each other by a host bus 904 composed of a CPU bus or the like.

The host bus 904 is connected to an external bus 906 such as a PCI (Peripheral Component Interconnect / Interface) bus via a bridge 905. It is not always necessary to separately configure the host bus 904, the bridge 905, and the external bus 906, and these functions may be implemented in one bus.

The input device 908 includes input means for the user to input information such as a mouse, keyboard, touch panel, buttons, microphone, switch, and lever, and an input control circuit that generates an input signal based on the input by the user and outputs the input signal to the CPU 901. And so on. By operating the input device 908, the user who operates the information processing device 900 can input various data to the information processing device 900 and instruct the processing operation.

The output device 909 includes, for example, a CRT (Cathode Ray Tube) display device, a liquid crystal display (LCD) device, an OLED (Organic Light Emitting Node) device, a display device such as a lamp, and an audio output device such as a speaker.

The storage device 910 is a device for storing data. The storage device 910 may include a storage medium, a recording device for recording data on the storage medium, a reading device for reading data from the storage medium, a deleting device for deleting the data recorded on the storage medium, and the like. The storage device 910 is composed of, for example, an HDD (Hard Disk Drive). The storage device 910 drives a hard disk and stores programs and various data executed by the CPU 901.

The communication device 911 is, for example, a communication interface composed of a communication device or the like for connecting to a network. Further, the communication device 911 may support either wireless communication or wired communication.

The hardware configuration example of the traffic condition detection device 1 according to the first embodiment of the present invention has been described above.

(3. Summary)
As described above, according to the embodiment of the present invention, the detection result of the vehicle traveling at the predetermined position on the road is acquired from the vehicle detection unit, and the vehicle corresponds to the predetermined position based on the detection result of the vehicle. Based on the traffic volume calculation unit that calculates the traffic volume to be used and statistical information on vehicle running on the road, it is determined whether the traffic flow state on the road is a congested flow or a free flow, and the traffic flow state is determined. Based on the statistical information analysis unit that obtains the determination result of the above, the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance. Provided is a traffic condition detection device including a speed determination unit for determining a vehicle speed corresponding to a position.

According to such a configuration, a technique is provided that enables the vehicle speed to be measured with a simple configuration without the need to be externally provided with information on the traffic flow state at the target point while suppressing the required cost.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or modifications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

1, 2 Traffic condition detector 112 Probe antenna 114, 116 Free flow antenna 121 Probe data storage unit 122 Free flow data storage unit 123 QV diagram storage unit 130 QV diagram creation unit 140 Traffic volume calculation unit 150 Speed calculation unit 151 Traffic volume Series change judgment unit 152 Vehicle passing interval judgment unit 153 Time required time judgment unit 156 Speed judgment unit 160 Statistical information analysis unit

Claims (16)

A traffic volume calculation unit that acquires the detection result of a vehicle traveling at a predetermined position on the road from the vehicle detection unit and calculates the traffic volume corresponding to the predetermined position based on the detection result of the vehicle.
Based on the statistical information on the vehicle running on the road, the statistical information analysis unit that determines whether the traffic flow condition on the road is a congested flow or a free flow and obtains the determination result of the traffic flow condition.
Speed determination to determine the vehicle speed corresponding to the predetermined position based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance. Department and
A traffic condition detection device equipped with. The statistical information includes information on changes in traffic volume over time.
The statistical information analysis unit determines whether the traffic flow state on the road is a congested flow or a free flow based on the information regarding the time-series change of the traffic volume.
The traffic condition detection device according to claim 1. When the traffic volume decreases from a predetermined upper limit traffic volume or more to a predetermined lower limit traffic volume or less within a predetermined time, the statistical information analysis unit changes the traffic flow state corresponding to the predetermined position to a congested flow. To judge,
The traffic condition detection device according to claim 2. When the traffic volume increases to a predetermined upper limit traffic volume or more, the statistical information analysis unit determines that the traffic flow state corresponding to the predetermined position has changed to a congested flow.
The traffic condition detection device according to claim 2 or 3. When the traffic volume decreases to a predetermined lower limit traffic volume or less, the statistical information analysis unit determines that the traffic flow state corresponding to the predetermined position has changed to a free flow.
The traffic condition detection device according to any one of claims 2 to 4. The statistical information includes information regarding the vehicle passing time interval.
The statistical information analysis unit determines whether the traffic flow state on the road is a congested flow or a free flow based on the information regarding the vehicle passing time interval.
The traffic condition detection device according to any one of claims 1 to 5. When the fitting degree between the distribution of the vehicle passing time interval and the predetermined distribution exceeds the threshold value, the statistical information analysis unit determines that the traffic flow state is a free flow, and the fitting degree sets the threshold value. If it falls below, it is determined that the traffic flow condition is a congested flow.
The traffic condition detection device according to claim 6. The traffic state detection device determines whether the traffic flow state on the road is a congested flow or a free flow based on the detection time difference of the same vehicle by a plurality of vehicle detection units, and determines whether the traffic flow state is a congested flow or a free flow. Equipped with a required time judgment unit to obtain the judgment result
The speed determination unit determines the vehicle speed corresponding to the predetermined position based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship.
The traffic condition detection device according to any one of claims 1 to 7. The required time determination unit determines that the traffic flow state is a congested flow when the detection time difference exceeds the predetermined time difference, and when the detection time difference is less than the predetermined time difference. Determines that the traffic flow state is free flow,
The traffic condition detection device according to claim 8. The traffic condition detection device is
A correspondence relationship creation unit that creates the correspondence relationship based on the traffic volume calculated in advance by the traffic volume calculation unit and the vehicle speed acquired in advance by the vehicle speed acquisition unit is provided.
The traffic condition detection device according to any one of claims 1 to 9. The correspondence creation department
When the vehicle speed for a predetermined period acquired by the vehicle speed acquisition unit does not include a vehicle speed of a predetermined speed or less or a vehicle speed of a predetermined speed or less that has continued for more than a predetermined duration. Exclude the traffic volume and vehicle speed for the predetermined period from the data for creating the correspondence.
The traffic condition detection device according to claim 10. The vehicle speed acquisition unit includes a probe antenna.
The traffic condition detecting device according to claim 10 or 11. The vehicle detection unit detects the vehicle in real time.
The traffic condition detection device according to any one of claims 1 to 12. The vehicle detector includes a free-flow antenna.
The traffic condition detection device according to claim 13. Obtaining the detection result of a vehicle traveling at a predetermined position on the road from the vehicle detection unit, and calculating the traffic volume corresponding to the predetermined position based on the detection result of the vehicle.
Based on the statistical information on the vehicle running on the road, it is determined whether the traffic flow state on the road is a congested flow or a free flow, and the determination result of the traffic flow state is obtained.
Based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance, the vehicle speed corresponding to the predetermined position is determined. ,
Traffic condition detection methods, including. Computer,
A traffic volume calculation unit that acquires the detection result of a vehicle traveling at a predetermined position on the road from the vehicle detection unit and calculates the traffic volume corresponding to the predetermined position based on the detection result of the vehicle.
Based on the statistical information on the vehicle running on the road, the statistical information analysis unit that determines whether the traffic flow condition on the road is a congested flow or a free flow and obtains the determination result of the traffic flow condition.
Speed determination to determine the vehicle speed corresponding to the predetermined position based on the determination result of the traffic flow state, the traffic volume corresponding to the predetermined position, and the correspondence relationship between the traffic volume and the vehicle speed prepared in advance. Department and
A program for functioning as a traffic condition detection device.

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