Traffic condition estimation device, traffic condition estimation method, and traffic condition estimation program

Abstract

To provide a technique capable of stably keeping track of a tail position of congestion.SOLUTION: A provisional determination unit provisionally determines, for each of a plurality of sections defined by dividing an observation target area in a vehicle traveling direction, whether the area is congested or not congested based on a traveling speed of a vehicle in the area. A confirmation unit corrects a provisional determination result for each section on the basis of a sequence of provisionally determined states in the traveling direction of the vehicle in the observation target area, and confirms a state of each section. An estimation unit estimates a tail of congestion on the basis of a state of each section confirmed in a fixing step.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a technique for estimating the end of a traffic jam that has occurred on a road on which a vehicle is traveling. [Background technology]

[0002] Conventionally, there have been devices that estimate traffic conditions in a target observation area by repeatedly scanning a defined area (target observation area) on a road on which vehicles travel using a probe wave and detecting the position and speed of vehicles traveling in the target observation area. The probe wave can be, for example, a millimeter wave (radio wave) or a laser beam. A device that uses millimeter waves as the probe wave is generally called a radio wave radar, and a device that uses laser beam as the probe wave is generally called a laser radar. Here, radio wave radar and laser radar are collectively referred to simply as radar devices.

[0003] For example, Patent Document 1 describes a device configured to estimate the tail position of a traffic jam vehicle as a traffic condition. The device described in Patent Document 1 determines whether a target vehicle is a traffic jam vehicle (traffic jam vehicle). When the device described in Patent Document 1 determines that the target vehicle is a traffic jam vehicle, it sets the following vehicle as the target vehicle and repeatedly determines whether the target vehicle is a traffic jam vehicle. A following vehicle is a vehicle that follows the target vehicle and is located upstream of the target vehicle. When the device described in Patent Document 1 determines that the target vehicle is not a traffic jam vehicle, it estimates the position of the target vehicle that was last determined to be a traffic jam vehicle to be the tail position of the traffic jam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5262907 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the device described in Patent Document 1, subtle changes in the vehicle's speed affect the result of determining whether the vehicle is in a traffic jam. Therefore, in the device described in Patent Document 1, the estimated end position of the traffic jam can become unstable due to the influence of subtle changes in the vehicle's speed.

[0006] An object of the present invention is to provide a technique that can stably detect the end position of a traffic jam. [Means for solving the problem]

[0007] In order to achieve the above object, the traffic situation estimation device of the present invention is configured as follows.

[0008] The detection data acquisition unit acquires detection data of vehicles traveling in the observation area detected by the radar device by scanning the observation area with a search wave. The radar device may be a radio wave radar that uses millimeter waves as the search wave, or a laser radar that uses laser light as the search wave. The vehicle detection data may include, for example, the position and speed of the vehicle.

[0009] The traveling speed acquisition unit processes the vehicle detection data acquired by the detection data acquisition unit, and acquires the traveling speed of the vehicle in each of a plurality of sections obtained by dividing the observation target area in the traveling direction of the vehicle. The traveling speed of the vehicle in each section may be set to, for example, the average value of the speeds of the vehicles traveling in that section. In this way, a stable speed state can be obtained for each section. Furthermore, the length of each section in the traveling direction of the vehicle may be set to, for example, several meters to several tens of meters (for example, 5 meters to 20 meters). Furthermore, the time required to calculate the average speed of the vehicles traveling in each section may be set to several minutes to several tens of minutes (for example, 1 minute to 20 minutes).

[0010] The provisional determination unit provisionally determines whether the state of each section is congested or not congested based on the vehicle's traveling speed in that section. For example, the provisional determination unit provisionally determines that a section is not congested if the vehicle's traveling speed acquired by the traveling speed acquisition unit is faster than the congestion threshold speed. In other words, the provisional determination unit provisionally determines that a section is congested if the vehicle's traveling speed acquired by the traveling speed acquisition unit is slower than the congestion threshold speed. The congestion threshold speed may be set to, for example, 5 to 10 km / h.

[0011] In this provisional determination, for example, even if the section is not congested, if there is an obstacle (such as something that has fallen onto the road from a preceding vehicle) that could hinder the vehicle's travel, the vehicle's speed may become slower than the congestion threshold speed in order to avoid the obstacle before and after this location, and the state may be determined to be congested. Also, in this provisional determination, for example, even in a congested section, the speed of a following vehicle that is late in starting because it does not notice the start of the preceding vehicle may become faster than the congestion threshold speed, and the state may be determined to be non-congested.

[0012] The determination unit corrects the provisional determination result of the state by the provisional determination unit based on the sequence of provisionally determined states in the vehicle's traveling direction in the observation target area, and determines the state of each section. For example, the determination unit groups sections that the provisional determination unit has provisionally determined to be congested and that are consecutive in the vehicle's traveling direction in the observation target area, and if the number of sections belonging to the group does not exceed a predetermined first set number, corrects the state of the sections belonging to the group to non-congested. Furthermore, the determination unit groups sections that the provisional determination unit has provisionally determined to be non-congested and that are consecutive in the vehicle's traveling direction in the observation target area, and if the number of sections belonging to the group does not exceed a predetermined second set number, corrects the state of the sections belonging to the group to congested. The first set number and the second set number may be the same value or different values. Furthermore, the first set number and the second set number are preferably set according to the length of the section in the vehicle's traveling direction.

[0013] This allows the determination unit to correct the determination result of the provisional determination unit depending on the vehicle's traveling conditions in the observation target area.

[0014] The estimation unit estimates the end of the congestion based on the state of each section determined by the determination unit. For example, when the state determined by the determination unit includes a section in which congestion and a section in which no congestion are present consecutively, and the upstream section is not congested, the estimation unit estimates that the downstream section is the end of the congestion.

[0015] Furthermore, the estimation unit may be configured to estimate the upstream section as the beginning of the congestion when the section determined by the determination unit as being congested and the section as being non-congested are consecutive and the upstream section is congested. With this configuration, the beginning and end of the congestion can be estimated, and the length of the congestion can be obtained.

[0016] In this way, with the above configuration, the end position of the traffic jam can be detected stably.

[0017] In addition, for example, a guidance unit that generates a guidance message in accordance with the end of the congestion estimated by the estimation unit may be additionally provided. With this configuration, it is possible to quickly and appropriately provide guidance about the congestion to drivers of vehicles traveling upstream of the congestion occurrence point. [Effects of the Invention]

[0018] According to the present invention, the end position of the traffic jam can be detected stably. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing a congestion end estimation system according to this example. [Figure 2] FIG. 2 is a diagram illustrating an observation area of ​​a radio radar. [Figure 3] 1 is a block diagram showing the configuration of a main part of a traffic situation estimation device of this example. [Figure 4] FIG. 10 is a diagram showing tracking data. [Figure 5] FIG. 10 is a diagram illustrating state information. [Figure 6] 10 is a flowchart showing a tracking process of the traffic condition estimation device. [Figure 7] 10 is a flowchart showing a determination process of the traffic condition estimation device. [Figure 8] 10 is a flowchart showing an estimation process of the traffic condition estimation device. [Figure 9] FIG. 2 is a block diagram showing the configuration of a main part of a traffic condition estimation device according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described.

[0021] <1. Application Examples> Fig. 1 is a schematic diagram showing a traffic jam end estimation system of this example. Fig. 2 is a diagram explaining the observation area of ​​the radio radar. The traffic jam end estimation system of this example detects whether traffic congestion has occurred on a road (e.g., a highway) on which a vehicle is traveling, and if it detects that traffic congestion has occurred, estimates the end of the traffic congestion.

[0022] The congestion tail estimation system of this example includes a traffic condition estimation device 1 and multiple radio wave radars 2 (2-1 to 2-n). The radio wave radar 2 is connected to the traffic condition estimation device 1 by wire or wirelessly. The radio wave radar 2 scans an assigned observation area SA with millimeter waves (search waves) and receives the reflected waves to detect the position and traveling speed (hereinafter simply referred to as speed) of a traveling vehicle 110. The radio wave radar 2 repeats scanning of the observation area SA at a predetermined period (e.g., 100 msec). As is well known, the radio wave radar 2 calculates the position of the traveling vehicle 110 (the vehicle 110 that reflected the search wave) using the direction in which the search wave was emitted and the time from when the search wave was emitted to when the reflected wave was received (the flight time). The radio wave radar 2 also calculates the speed of the traveling vehicle 110 (the vehicle 110 that reflected the search wave) using the frequency of the emitted search wave and the frequency of the received reflected wave.

[0023] The traffic congestion end estimation system of this example may include only one radio wave radar 2.

[0024] The radio radar 2 is installed so that the observation area SA is a section from a point Xm (e.g., 20m) away from the installation position in the traveling direction of the vehicle 110 to a point Ym (e.g., 150m) away from the installation position. The radio radar 2 also determines the range in which it scans the search waves in the width direction of the road so that the three lanes of the road shown in Fig. 1 fall within the observation area SA.

[0025] In addition, although Figures 1 and 2 show an example of installation in which the radio radar 2 emits a search wave toward the downstream side, it may also be installed so that the search wave is emitted toward the upstream side (the traveling direction shown in Figures 1 and 2 may be reversed).

[0026] As shown in FIG. 1, the congestion end estimation system of this example has multiple radio radars 2 (2-1 to 2-n) installed side by side in the traveling direction of the vehicle 110. Therefore, the observation areas SA of the multiple radio radars 2 are lined up in the traveling direction of the vehicle 110. The observation areas SA of two adjacent radio radars 2 may partially overlap, may be in contact with each other, or may be separated. However, if the observation areas SA of two adjacent radio radars 2 are separated from each other, there will be a section between the two adjacent observation areas SA in which the vehicle 110 cannot be detected.

[0027] Note that some of the vehicles 110 shown in Figures 1 and 2 are not labeled with reference numerals. In Figures 1 and 2, the vehicles 110 are not distinguished from one another by whether or not they are labeled, but are omitted for the sake of clarity.

[0028] Every time the radio radar 2 scans the observation area SA with a search wave, it outputs detection data of each vehicle 110 detected in the current scan to the traffic condition estimation device 1. The detection data of each vehicle 110 is data indicating the position and speed of the vehicle 110.

[0029] When detection data of the vehicle 110 is input from the radio radar 2, the traffic condition estimation device 1 acquires the speed of the vehicle 110 in each of a plurality of sections obtained by dividing an observation area SA of the radio radar 2 in the traveling direction of the vehicle 110. FIG. 2 shows an example in which the observation area SA is divided into m sections (first section to mth section) in the traveling direction of the vehicle 110. The length of each section in the traveling direction of the vehicle 110 is, for example, 5 m to 20 m. For each section, the traffic condition estimation device 1 may acquire the average speed of the vehicle 110 detected in that section as the speed of the vehicle 110 in that section, or may acquire the minimum speed of the vehicle 110 detected in that section as the speed of the vehicle 110 in that section.

[0030] The traffic condition estimation device 1 determines, for each radio radar 2, whether each section obtained by dividing the observation target area SA of the radio radar 2 is a congested section or a non-congested section for the vehicle 110. For example, the traffic condition estimation device 1 provisionally determines the state of a section where the speed of the vehicle 110 is faster than a predetermined congestion threshold speed (for example, 5 to 10 km / h) as non-congested, and provisionally determines the state of a section where the speed is slower than the congestion threshold speed as congested.

[0031] In this provisional determination, for example, even if the section is not congested, if there is a location where there is an obstacle (such as an object that has fallen onto the road from a leading vehicle) that is hindering the travel of vehicle 110, the speed of vehicle 110 may become slower than the congestion threshold speed to avoid the obstacle before and after this location, and the state may be determined to be congested. Also, in this provisional determination, for example, even in a congested section, the speed of following vehicle 110 that does not notice the departure of leading vehicle 110 and is late in starting may become faster than the congestion threshold speed, and the state may be determined to be non-congested.

[0032] The traffic condition estimation device 1 corrects the provisionally determined result of the state of each section based on the sequence of provisionally determined states in the traveling direction of the vehicle 110 in the observation target area SA, and determines the state of each section. For example, the traffic condition estimation device 1 groups sections provisionally determined to be congested that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and corrects the state of the sections belonging to the group to non-congested if the number of sections belonging to the group does not exceed a predetermined first set number. Furthermore, the traffic condition estimation device 1 groups sections provisionally determined to be non-congested that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and corrects the state of the sections belonging to the group to congested if the number of sections belonging to the group does not exceed a predetermined second set number. The first set number and the second set number may be the same value or different values. Furthermore, the first set number and the second set number are preferably set according to the length of the section in the traveling direction of the vehicle. For example, if the provisionally determined state is not the same over a range of several tens of meters (20 to 50 meters), the traffic condition estimation device 1 determines that the result of the provisional determination is incorrect due to some traffic condition and corrects it.

[0033] When a section whose confirmed state is congestion and a section whose state is non-congestion are consecutive and the upstream section is non-congestion (in other words, when the downstream section is congested), the traffic condition estimation device 1 estimates that the downstream section is the end of the congestion.Furthermore, when a section whose confirmed state is congestion and a section whose state is non-congestion are consecutive and the upstream section is congested (in other words, when the downstream section is non-congestion), the traffic condition estimation device 1 estimates that the upstream section is the start of the congestion.

[0034] This allows the traffic condition estimation device 1 to stably detect the end position of the congestion.

[0035] <2.Configuration example> 3 is a block diagram showing the configuration of the main parts of the traffic situation estimation device of this example. The traffic situation estimation device 1 includes a control unit 11, a detection data input unit 12, a tracking DB 13, and an input / output unit 14.

[0036] The control unit 11 controls the operation of each part of the main body of the traffic condition estimation device 1. The control unit 11 also has a detection data acquisition unit 11a, a traveling speed acquisition unit 11b, a tentative determination unit 11c, a determination unit 11d, and an estimation unit 11e. The detection data acquisition unit 11a, the traveling speed acquisition unit 11b, the tentative determination unit 11c, the determination unit 11d, and the estimation unit 11e that the control unit 11 has will be described later.

[0037] The radio radars 2 (2-1 to 2-n) are connected to the detection data input unit 12. The radio radars 2 are connected to the traffic condition estimation device 1 by wire or wirelessly. Each time the radio radar 2 scans the observation target area SA with a search wave, it outputs detection data for each vehicle 110 detected in the current scan, which corresponds to the position and speed of that vehicle 110. The detection data output by each connected radio radar 2 is input to the detection data input unit 12.

[0038] The tracking DB 13 stores tracking data of vehicles 110 detected by the radio radar 2. The tracking data is stored for each radio radar 2 and for each vehicle 110 detected by that radio radar 2. FIG. 4 is a diagram showing tracking data. FIG. 4 shows an example of tracking data for a vehicle 110 detected by a radio radar 2-n with an ID of "123456789." The tracking data is data in which the ID for identifying the vehicle 110 is associated with detection data at each detection time. The detection time may be, for example, the time when the radio radar 2 starts scanning the observation area SA with the search wave, the time when it finishes scanning, a time between the start time and the end time, or the time when the detection data is input from the radio radar 2.

[0039] The detection data includes the speed and position of the detected vehicle 110. The position is the position in the direction of travel of the vehicle 110 in the observation area SA and the position in the width (total width) direction of the vehicle 110. The position in the direction of travel of the vehicle 110 corresponds to the distance from the installation position of the radio radar 2 to the vehicle 110. Furthermore, the position in the width direction of the vehicle 110 corresponds to the lane in which the vehicle 110 is traveling.

[0040] The traffic condition estimation device 1 may be configured to perform processing to identify the detected vehicle 110 between the radio radars 2, or may be configured not to perform processing to identify the detected vehicle 110 between the radio radars 2.

[0041] The input / output unit 14 inputs and outputs data to and from a higher-level device (for example, a server device) installed in, for example, a control center.

[0042] Next, the detection data acquisition unit 11a, the traveling speed acquisition unit 11b, the tentative determination unit 11c, the determination unit 11d, and the estimation unit 11e included in the control unit 11 will be described.

[0043] The detection data acquisition unit 11a processes the detection data of the vehicle 110 input from the radio radar 2 and stores it in the tracking DB 13. The detection data acquisition unit 11a performs an identification process to associate the vehicle 110 detected by the radio radar 2 during the current scan of the observation area SA using the search wave with the vehicle 110 detected during the previous scan of the observation area SA using the search wave.

[0044] The identification process here refers to a process for identifying a vehicle 110 detected by the same radio radar 2, and not a process for identifying a vehicle 110 detected between two radio radars 2.

[0045] The detection data acquisition unit 11a sets the ID of the vehicle 110 detected by the radio radar 2 in the scan of the observation area SA with the current search wave to the ID of the vehicle 110 detected in the previous scan of the observation area SA with the associated search wave. Furthermore, if the detection data acquisition unit 11a cannot associate the vehicle 110 detected by the radio radar 2 in the scan of the observation area SA with the current search wave with the vehicle 110 detected in the previous scan of the observation area SA with the search wave, it assigns a new ID to the vehicle 110 detected this time.

[0046] For the radio radar 2 to which detection data has been input, the traveling speed acquisition unit 11b acquires the speed of the vehicle 110 for each divided section of the observation target area SA of the radio radar 2. As the traveling speed of the vehicle in each section, the traveling speed acquisition unit 11b may acquire, for example, the average speed of the vehicle traveling in that section, or may acquire the minimum speed of the vehicle 110 traveling in that section, or may acquire the minimum speed of the vehicle 110 detected in that section as the speed of the vehicle 110 in that section.

[0047] In the following description, the section M into which the observation area SA of the radio radar 2-N is divided may be referred to as section NM for convenience. N is 1 to n. M is 1 to m.

[0048] When detection data of the vehicle 110 is input from the radio radar 2-N, the traffic condition estimation device 1 has the traveling speed acquisition unit 11b acquire the traveling speed of the vehicle 110 in each section NM belonging to the observation area SA of the radio radar 2-N.

[0049] The provisional determination unit 11c provisionally determines whether the state of each section for which the traveling speed of the vehicle 110 has been acquired by the traveling speed acquisition unit 11b is congested or non-congested. In this example, the provisional determination unit 11c provisionally determines that the state of a section for which the traveling speed of the vehicle 110 acquired by the traveling speed acquisition unit 11b exceeds a predetermined congestion threshold speed is non-congested, and provisionally determines that the state of a section for which the traveling speed of the vehicle 110 acquired by the traveling speed acquisition unit 11b does not exceed the congestion threshold speed is congested. The congestion threshold speed is, for example, 5 to 10 km / h.

[0050] The determination unit 11d corrects the provisional determination result of the state of each section based on the sequence of provisionally determined states in the traveling direction of the vehicle 110 in the observation target area SA, and determines the state of each section. For example, the determination unit 11d groups sections that have been provisionally determined to be congested and that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and if the number of sections belonging to that group does not exceed a predetermined first set number, corrects the state of the sections belonging to that group to non-congested. Furthermore, the determination unit 11d groups sections that have been provisionally determined to be congested and that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and if the number of sections belonging to that group exceeds a predetermined first set number, leaves the state of the sections belonging to that group as congested.

[0051] Furthermore, the determination unit 11d groups sections that are provisionally determined to be non-congested and that are consecutive in the direction of travel of the vehicle 110 in the observation area SA, and if the number of sections that belong to the group does not exceed a predetermined second set number, corrects the state of the sections that belong to the group to congested. Furthermore, the determination unit 11d groups sections that are provisionally determined to be non-congested and that are consecutive in the direction of travel of the vehicle 110 in the observation area SA, and if the number of sections that belong to the group exceeds a predetermined second set number, keeps the state of the sections that belong to the group as non-congested.

[0052] The first set number and the second set number may be the same value (number) or different values. The first set number and the second set number are preferably set according to the length of the section in the vehicle's traveling direction. For example, in this example, if the provisionally determined state is not the same over several tens of meters (20 m to 50 m), the determination unit 11d determines that the provisionally determined result is incorrect due to some traffic condition and corrects it.

[0053] The determination unit 11d updates the state of the section whose state has been determined this time. For example, the traffic condition estimation device 1 stores state information in memory that registers the state of each section. FIG. 5 is a diagram illustrating this state information. The state information is data indicating the state determined by the determination unit 11d for each section (section 1-1 to section nm). In FIG. 5, sections whose state determined by the determination unit 11d is congestion are shown by hatching. In other words, in FIG. 5, sections whose state determined by the determination unit 11d is non-congestion are not shown by hatching.

[0054] 5, the point where a section in a congested state and a section in a non-congested state are consecutive in the traveling direction of the vehicle 110 is the beginning or end of the congestion. Specifically, if the downstream section is in a non-congested state and the upstream section is in a congested state, the upstream section is the beginning of the congestion. Also, if the downstream section is in a congested state and the upstream section is in a non-congested state, the downstream section is the end of the congestion.

[0055] The estimation unit 11e estimates the position of the end of the traffic jam by referring to the state information shown in FIG. 5 at a predetermined estimation period (for example, every several tens of seconds to several minutes). That is, the estimation unit 11e can estimate the end of the traffic jam at the estimation period. The estimation unit 11e associates the estimated end position of the traffic jam with the estimated time and stores them in a memory. As a result, the memory stores changes in the position of the end of the traffic jam over time.

[0056] In addition, the estimation unit 11e may estimate the end position of the congestion when detection data of the vehicle 110 is input from any of the radio radars 2, the provisional judgment unit 11c provisionally judges the state of each section of the observation area SA of that radio radar 2 as being congested or not, and the determination unit 11d updates the state information shown in Figure 5.

[0057] Furthermore, the estimation unit 11e may estimate the end position of the traffic jam when detection data of the vehicle 110 is input from a radio radar 2 that belongs to the observation area SA and a radio radar 2 that is located upstream of this radio radar 2, the provisional judgment unit 11c provisionally judges the state of each section of the observation area SA of the radio radar 2 as being congested or not congested, and the determination unit 11d updates the state information shown in Figure 5.

[0058] The traffic condition estimation device 1 in this example may or may not estimate the section that is the head of the congestion. By estimating the section that is the head of the congestion, the traffic condition estimation device 1 can acquire the change in the congestion length (the length from the head to the tail of the congestion) over time.

[0059] The control unit 11 of the traffic condition estimation device 1 is composed of a hardware CPU, memory, and other electronic circuits. When the hardware CPU executes the traffic condition estimation program according to the present invention, it operates as a detection data acquisition unit 11a, a traveling speed acquisition unit 11b, a tentative determination unit 11c, a determination unit 11d, and an estimation unit 11e. The memory also has an area for expanding the traffic condition estimation program according to the present invention and an area for temporarily storing data generated during execution of the traffic condition estimation program. The control unit 11 may be an LSI that integrates the hardware CPU, memory, and the like. The hardware CPU is also a computer that executes the traffic condition estimation method according to the present invention.

[0060] <3. Example of operation> 6 is a flowchart showing the tracking process of the traffic condition estimation device of this example. The tracking process is a process of processing the detection data of the vehicle 110 input from any of the radio radars 2, generating the tracking data shown in FIG. 4, and storing it in the tracking DB 13.

[0061] The traffic condition estimation device 1 waits (s1) for detection data output from any of the radio radars 2 to be input to the detection data input unit 12. In this example, the radio radar 2 scans the assigned observation area SA with search waves, and outputs detection data for each vehicle 110 detected during the current scan, associating the vehicle 110 with its position and speed. The radio radar 2 also scans the observation area SA with search waves at 100 msec intervals. Therefore, in this example, the traffic condition estimation device 1 receives detection data from each radio radar 2 input to the detection data input unit 12 at 100 msec intervals.

[0062] The detection data acquisition unit 11a selects a target vehicle from among the vehicles 110 detected this time that have not undergone the processes of s3 to s7 described below (unprocessed vehicles 110) (s2). The detection data acquisition unit 11a determines whether the target vehicle selected in s2 is a vehicle 110 that was detected previously (s3). In s3, the position and speed of the target vehicle are used to determine whether the corresponding vehicle 110 was detected previously.

[0063] If the target vehicle is a vehicle 110 that was also detected last time, the detection data acquisition unit 11a matches the ID of this target vehicle to the ID assigned last time (s4), and adds the detection data of the current target vehicle to the tracking data of the vehicle 110 with this ID stored in the tracking DB 13 (s5).

[0064] If the target vehicle is a vehicle 110 that was not detected last time, the detection data acquisition unit 11a issues and assigns an ID to this target vehicle (s6). The detection data acquisition unit 11a registers the tracking data of the target vehicle to which the newly issued ID has been assigned in the tracking DB 13 (s7). In s6, an ID that can be distinguished from other vehicles 110 is issued. The tracking data registered in s7 contains only the current detection data.

[0065] After performing the process of s5 or s7, the detection data acquisition unit 11a determines whether or not there is an unprocessed vehicle 110 that has been detected this time by the radio radar 2 and has not yet been subjected to the processes of s3 to s7 (s8). If there is an unprocessed vehicle 110, the detection data acquisition unit 11a returns to s2. If there is no unprocessed vehicle 110, the detection data acquisition unit 11a returns to s1.

[0066] By performing this tracking process, the traffic situation estimation device 1 in this example acquires tracking data for each radio radar 2 indicating the travel trajectory of the vehicle 110 detected within the observation area SA assigned to that radio radar 2.

[0067] As is clear from the above description, the tracking data of each vehicle 110 registered in the tracking DB 13 is updated based on the detection data of the vehicle 110 input from each radio wave radar 2.

[0068] 7 is a flowchart showing the determination process of the traffic condition estimation device 1 of this example. The traffic condition estimation device 1 of this example waits for the tracking data to be updated by the tracking process shown in FIG. 6 (s11). When the tracking data is updated, the traveling speed acquisition unit 11b of the traffic condition estimation device 1 acquires the speed of the vehicle 110 in each section belonging to the observation target area SA for which the tracking data has been updated this time (s12). The traveling speed acquisition unit 11b performs the process of s12 by, for example, referring to the tracking data stored in the tracking DB 13.

[0069] The provisional determination unit 11c provisionally determines the state (congestion or non-congestion) for each section in the observation area SA for which the tracking data has been updated this time (s13). The provisional determination unit 11c provisionally determines that a section in which the traveling speed of the vehicle 110 acquired by the traveling speed acquisition unit 11b exceeds a predetermined congestion threshold speed is a non-congestion section, and provisionally determines that a section in which the traveling speed of the vehicle 110 acquired by the traveling speed acquisition unit 11b does not exceed the congestion threshold speed is a congestion section.

[0070] The determination unit 11d corrects the provisional determination result of the state of each section based on the sequence of provisionally determined states in the traveling direction of the vehicle 110 in the observation target area SA, and determines the state of each section (s14). In this example, the determination unit 11d groups sections that have been provisionally determined to be congested and that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and if the number of sections belonging to that group does not exceed a predetermined first set number, corrects the state of the sections belonging to that group to non-congested. Furthermore, the determination unit 11d groups sections that have been provisionally determined to be congested and that are consecutive in the traveling direction of the vehicle 110 in the observation target area SA, and if the number of sections belonging to that group exceeds a predetermined first set number, leaves the state of the sections belonging to that group as congested.

[0071] Furthermore, the determination unit 11d groups sections that are provisionally determined to be non-congested and that are consecutive in the direction of travel of the vehicle 110 in the observation area SA, and if the number of sections that belong to the group does not exceed a predetermined second set number, corrects the state of the sections that belong to the group to congested. Furthermore, the determination unit 11d groups sections that are provisionally determined to be non-congested and that are consecutive in the direction of travel of the vehicle 110 in the observation area SA, and if the number of sections that belong to the group exceeds a predetermined second set number, keeps the state of the sections that belong to the group as non-congested.

[0072] The determination unit 11d updates the state information stored in the memory (s15), and the process returns to s11.

[0073] In this way, the traffic condition estimation device 1 of this example can stably update the state of each section by performing this determination process.

[0074] 8 is a flowchart showing the estimation process of the traffic condition estimation device of this example. The estimation unit 11e waits for the estimation timing to arrive (s21). When the estimation timing arrives, the estimation unit 11e refers to the state information stored in memory and extracts a location where a congested section and a non-congested section are connected (s22). If, at the location extracted at s22, the state of the downstream section is non-congested and the state of the upstream section is congested, the estimation unit 11e estimates that the upstream section is the beginning of the congestion (s23). Furthermore, if, at the location extracted at s22, the state of the downstream section is congested and the state of the upstream section is non-congested, the estimation unit 11e estimates that the downstream section is the end of the congestion (s24).

[0075] The traffic condition estimation device 1 outputs the estimation result, which associates the first section of the congestion estimated by the estimation unit 11e in s23, the last section of the congestion estimated in s24, and the current estimated time, to the higher-level device (s25), and returns to s21.

[0076] In this way, the traffic condition estimation device 1 of this example can estimate the positions of the beginning and end of a traffic jam at the estimation timing cycle. In other words, if the estimation timing cycle is shortened, the positions of the beginning and end of a traffic jam can be stably estimated.

[0077] In addition, since the traffic situation estimation device 1 in this example estimates the beginning and end of the congestion, it can also determine whether the current situation is one in which the congestion length will become longer (a situation in which the congestion is getting worse) or one in which the congestion length will become shorter (a situation in which the congestion is improving).

[0078] <4. Modifications> Variation 1 9 is a block diagram showing the configuration of the main parts of a traffic situation estimation device according to Modification 1. A traffic situation estimation device 1A of Modification 1 differs from the above examples in that a control unit 11A has a guide unit 11f.

[0079] When the estimation unit 11e estimates the end of the traffic jam, the guidance unit 11f generates a guidance message to be displayed on a guide board installed on the road according to the position of the estimated end of the traffic jam, and outputs the generated message to the guide board. At this time, the guidance unit 11f generates a guidance message according to the estimated end position of the traffic jam and the position where the guide board is installed. This allows information about the end of the traffic jam to be provided stably to the driver of the vehicle 110.

[0080] Furthermore, as described above, the traffic condition estimation device 1A repeatedly estimates the end position at the estimation timing period, and therefore can predict changes in the position of the end of the congestion over time. Therefore, the guidance unit 11f may be configured to generate a guidance message taking into consideration not only the estimated end position of the congestion and the position where the guide board is installed, but also the predicted change in the position of the end of the congestion over time.

[0081] Variation 2 The traffic condition estimation device 1 described above is designed to estimate the head and tail of a traffic jam, but it may estimate only the tail of the traffic jam.

[0082] Variation 3 The traffic condition estimation device 1 described above stores the estimated end position of the congestion in memory in association with the time when the estimation was made by the estimation unit 11e. The traffic condition estimation device 1 may estimate the traffic congestion extension speed from the change in the end position of the congestion over time.

[0083] It should be noted that this invention is not limited to the above-described embodiments, and that the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. Furthermore, the order of each step in the flowcharts described in all the above examples is merely an example, and may be appropriately changed within the scope of the present invention.

[0084] Furthermore, the correspondence between the configuration according to the present invention and the configuration according to the above-described embodiment can be described as follows: <Additional Notes> a detection data acquisition unit (11a) that acquires detection data of a vehicle (110) traveling in an observation area (SA) detected by a radar device (2) scanning the observation area (SA) with a search wave; a traveling speed acquisition unit (11b) that processes the detection data of the vehicle (110) acquired by the detection data acquisition unit (11a) and acquires the traveling speed of the vehicle (110) in each of a plurality of sections that are obtained by dividing the observation target area (SA) in the traveling direction of the vehicle (110); a provisional determination unit (11c) for provisionally determining whether the state of each section is congested or not based on the traveling speed of the vehicle in the section; a determination unit (11d) that corrects the provisional determination result of the state by the provisional determination unit (11c) based on a sequence of provisionally determined states in the traveling direction of the vehicle (110) in the observation target area (SA) and determines the state of each section; The traffic situation estimation device (1) includes an estimation unit (11e) that estimates the end of the congestion based on the state of each section determined by the determination unit (11d). [Explanation of symbols]

[0085] SA: Observation area 1, 1A...Traffic situation estimation device 2...Radio wave radar 11, 11A...Control unit 11a…Detection data acquisition unit 11b...Travel speed acquisition unit 11c…Temporary Judgment Section 11d...Confirmation part 11e…Estimation part 11f…Information department 12...Detection data input section 13...Tracking database (Tracking DB) 14…Input / output section 110...Vehicle

Claims

1. a detection data acquisition unit that acquires detection data of vehicles traveling in an observation target area detected by a radar device by scanning the observation target area with a search wave; a travel speed acquisition unit that processes the vehicle detection data acquired by the detection data acquisition unit, and acquires the vehicle travel speed in each of a plurality of sections obtained by dividing the observation target area in the vehicle travel direction; a provisional determination unit that provisionally determines whether the state of each section is congested or not congested based on the traveling speed of the vehicle in the section; a determination unit that corrects a provisional determination result of the state by the provisional determination unit based on a sequence of provisionally determined states in the vehicle traveling direction in the observation target area, and determines the state of each section; an estimation unit that estimates the end of congestion based on the state of each section determined by the determination unit, The determination unit groups sections that the provisional judgment unit has provisionally judged to be non-congested and that are continuous in the direction of vehicle travel in the observation area, and if the number of sections belonging to the group does not exceed a predetermined second set number, corrects the status of the sections belonging to the group to congested.

2. The traffic condition estimation device according to claim 1 , wherein the provisional determination unit provisionally determines that a section in which the vehicle's traveling speed is slower than a predetermined congestion threshold speed is congested.

3. 3. The traffic condition estimation device according to claim 1, wherein the determination unit groups sections that the provisional judgment unit has provisionally judged to be congested and that are continuous in the direction of vehicle travel in the observation area, and if the number of sections belonging to the group does not exceed a predetermined first set number, corrects the status of the sections belonging to the group to non-congested.

4. 4. The traffic situation estimation device according to claim 1, further comprising a guidance unit that generates a guidance message in accordance with the end of the congestion estimated by said estimation unit.

5. A traffic condition estimation device as described in any one of claims 1 to 4, wherein the estimation unit estimates that the downstream section is the section that constitutes the end of the congestion when the state determined by the determination unit is a section that is congested and a section that is not congested, and the upstream section is not congested.

6. A traffic condition estimation device as described in any one of claims 1 to 5, wherein when the state determined by the determination unit is a congested section followed by a non-congested section, and the upstream section is congested, the estimation unit estimates that the upstream section is the section that constitutes the head of the congestion.

7. a detection data acquisition step of acquiring detection data of vehicles traveling in an observation area detected by the radar device by scanning the observation area with a search wave; a travel speed acquisition step of processing the vehicle detection data acquired in the detection data acquisition step, and acquiring the vehicle travel speed in each of a plurality of sections obtained by dividing the observation area in the vehicle travel direction; a provisional determination step of provisionally determining, for each section, whether the state of the section is congested or not congested based on the traveling speed of the vehicle in the section; a determination step of correcting the provisional determination result of the state in the provisional determination step based on the sequence of provisionally determined states in the vehicle traveling direction in the observation target area, and determining the state of each section; an estimation step of estimating the end of congestion based on the state of each section determined in the determination step, A traffic situation estimation method characterized in that in the determination step, sections that have been provisionally determined to be non-congested in the provisional determination step and that are continuous in the direction of vehicle travel in the observation area are grouped, and if the number of sections belonging to the group does not exceed a predetermined second set number, the status of the sections belonging to the group is corrected to congested.

8. a detection data acquisition step of acquiring detection data of vehicles traveling in an observation area detected by the radar device by scanning the observation area with a search wave; a travel speed acquisition step of processing the vehicle detection data acquired in the detection data acquisition step, and acquiring the vehicle travel speed in each of a plurality of sections obtained by dividing the observation area in the vehicle travel direction; a provisional determination step of provisionally determining, for each section, whether the state of the section is congested or not congested based on the traveling speed of the vehicle in the section; a determination step of correcting the provisional determination result of the state in the provisional determination step based on the sequence of provisionally determined states in the vehicle traveling direction in the observation target area, and determining the state of each section; an estimation step of estimating the end of congestion based on the state of each section determined in the determination step, A traffic situation estimation program characterized in that in the confirmation step, sections that have been provisionally determined to be non-congested in the provisional determination step and that are continuous in the direction of vehicle travel in the observation area are grouped, and if the number of sections belonging to the group does not exceed a predetermined second set number, the status of the sections belonging to the group is corrected to congested.

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