JP2018022398A - Route identification device, route identification system and route identification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately perform processing of estimating a travel route with small processing load by associating a positioning point indicated by probe data with a reference point in a map.SOLUTION: A route identification device includes: a probe data reception part for receiving probe data which is a time-sequential travel trajectory of a travel terminal device from the travel terminal device; and a matching part for matching a route through which the travel terminal device is considered to have actually traveled in a different method which corresponds to a time cycle to generate the probe data. The matching part matches a positioning point included in the probe data to a reference point in a map and regards a road to which the reference point belongs as a part of a route through which the travel terminal device is considered to have actually traveled when the time cycle is shorter than a prescribed standard, while it matches the positioning point to the reference point and also matches a route through which the travel terminal device is considered to have actually traveled from a plurality of route candidates connecting among a plurality of reference points when the time cycle is longer than the prescribed standard.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a route identification device, a route identification system, and a route identification method.

  A mobile terminal device that changes its position from moment to moment, such as a portable terminal device or a car navigation device, can generate its own location information in real time by calculating signals received from multiple GPS (Global Positioning System) satellites. it can. Recently, based on such position information, a technique for specifying a position of a mobile terminal device on a map and further specifying a route traveled by the mobile terminal device has become widespread. And road traffic information etc. will be created based on the route specified in this way. In many cases, a user of a mobile terminal device moves by means such as a vehicle, a railroad, or a walk. Therefore, it is usually impossible to fly and travel in the shortest distance from a certain point to another point, and therefore information processing for specifying the route through which the user has passed is always necessary. The route here is, for example, a series of roads, railway lines, etc. on a map.

  In the technology for specifying a route in this way, the mobile terminal device is discrete (intermittent) with position information (latitude, longitude), time information, and its identification information in a server or the like at a predetermined time period or distance period. Send). The information transmitted in this way indicates a time-series movement trajectory of the mobile terminal apparatus and is generally called “probe data”.

  The movement route estimation system of Patent Literature 1 receives probe data from a mobile terminal device. When the mobile terminal device generates its own location information, a positioning error occurs. That is, it is not always guaranteed that the “positioning point” indicated by the latitude and longitude of the probe data is on the road or railway line on the map. Therefore, the movement route estimation system of Patent Document 1 associates a positioning point with a reference point on a map that the mobile terminal device is thought to have actually passed. The reference point is located on a road or railway line located near the positioning point. In addition, the movement route estimation system disclosed in Patent Document 1 estimates that a route time closest to the actual travel time among a plurality of route candidates connecting a plurality of reference points is an actual route.

Japanese Patent No. 5330445

  However, Patent Document 1 does not disclose a specific method for making a positioning point correspond to a reference point on a map (paragraph 0016 of Patent Document 1), and a positioning point with low positioning accuracy is simply ignored. (Patent Document 1, paragraph 0030). In order to estimate the route, it is a natural premise that the positioning point correctly corresponds to the reference point. If it is attempted to specify a route that connects only reference points with high positioning accuracy while ignoring positioning points with low positioning accuracy, there are many route candidates and the processing load increases. Further, even when positioning points with high positioning accuracy are consecutive, it is unclear whether or not the reference point associated with the positioning points reflects the true position of the mobile terminal device with high accuracy. . Then, the route cannot be reproduced correctly.

In order to reduce the reference point specifying error (matching error) caused by such positioning error, it is conceivable to shorten the cycle in which the mobile terminal apparatus generates and transmits the probe data. However, even if it does so, the processing load on the side that transmits and receives the probe data increases, and the real-time property is sacrificed for the increase in communication cost.
Therefore, an object of the present invention is to realize a process of estimating a movement route based on probe data with high accuracy and a low processing load.

The path identification device of the present invention includes a probe data receiving unit that receives probe data, which is a time-series movement trajectory of a mobile terminal device, from the mobile terminal device, and a mobile terminal device in a different manner corresponding to the cycle in which the probe data is generated. And a matching unit that matches a route that is considered to have actually moved.
Other means will be described in the embodiment for carrying out the invention.

  According to the present invention, it is possible to realize a process of estimating a movement route based on probe data with high accuracy and a low processing load.

It is a figure explaining a road density and a probe period. It is a figure explaining the method of matching. (A) is a figure explaining the matching method in case a probe period is short. (B) is a figure explaining the matching method in case a probe period is long. It is a figure explaining the structure of a route identification apparatus. It is a flowchart of a processing procedure. It is a figure explaining a planned route and an attention area.

  Hereinafter, a mode for carrying out the present invention (referred to as “the present embodiment”) will be described in detail with reference to the drawings. Specifically, an example will be described in which the route identification device receives probe data from a mobile terminal device (car navigation device) mounted on an automobile traveling on a road. In the present invention, when the mobile terminal device is a portable terminal device other than the car navigation device, the moving means on which the mobile terminal device is mounted is a vehicle other than an automobile, a railroad, a walking, etc., the moving means is a road. The present invention can also be applied when moving on other tracks.

(the term)
A mobile terminal device is a device that can generate probe data (immediately described later) while moving on the earth, regardless of whether it moves with its own power or is carried by another device or a person. .
The probe data is data including position information (latitude and longitude) on the earth where the mobile terminal device is located and a point in time when the position information is generated. It can be said that the probe data is a time-series movement locus of the mobile terminal device. The probe data is usually generated by the mobile terminal device itself based on a signal received from a GPS satellite. The probe data may include the direction in which the mobile terminal device moves (0 to 360 degrees, where north is 0 degree). Even if the probe data does not include a direction, the moving direction can be specified by the positional relationship between the two points before and after.

The probe period is the length of the interval at which probe data is generated. The interval may be a time interval or a distance interval. For example, when the mobile terminal device generates probe data every 5 minutes, the probe cycle is “5 minutes”. When the probe data is generated every time the mobile terminal device moves 1 km, the probe cycle is “1 km”.
A map is a plane having latitude and longitude on the earth as two coordinate axes (spatial coordinates including height information may be used, but in this embodiment, for ease of explanation, a plane map is used. The natural object and the artificial object existing on the earth are drawn at the positions indicated by the coordinate values.

A positioning point is a point indicated by position information included in probe data. As described above, the coordinate value (x, y) of the positioning point includes a positioning error and is different from the true coordinate value where the mobile terminal device is located. Therefore, if an attempt is made to directly display a positioning point on a map, in an extreme case, the positioning point may be displayed on the sea.
The reference point is a point on the map corresponding to the positioning point. The route identification device according to the present embodiment considers that a reference point on a road on which a vehicle on which a mobile terminal device is mounted has moved. Now, when the positioning point (x, y) is made to correspond to the reference point (X, Y), even if the positioning point (x, y) on the map is on the sea, the reference point (X, Y) on the map For example on a road along the coast. Note that the term “reference” includes the meaning that a route is searched based on that point.

A route is obtained by continuously connecting a plurality of roads estimated by a route identification device that a vehicle equipped with a mobile terminal device has traveled.
Matching means specifying (identifying) a reference point corresponding to a positioning point on a map. In general, the term “identify” is used as a technical term meaning “identify equivalents having the same meaning”. If the reference points are matched, the paths connecting the reference points can be matched (identified). The name “route identification device” in this embodiment includes this meaning.

The road density is an index that defines the degree of concentration of roads on a map for each two-dimensional area or each one-dimensional road. For example, the following index can be road density.
-Sum of road lengths in the XX city area-Number of intersections (including branch points) in the XX city area-Number of intersections from the ◎◎ intersection to the □□ intersection on the national road XX line

The degree of congestion is an index that defines the degree of congestion of vehicles for each two-dimensional area or each one-dimensional road. For example, the following index can be the congestion degree.
・ Number of vehicles currently driving in the area of XX city ・ Number of vehicles currently driving between the ◎◎ intersection of the national highway XX line □ ◎ From the ◎◎ intersection of the national highway XX line □□ Number of lanes to the intersection (the fewer lanes, the greater the congestion)
・ Current time (midnight congestion is less than other congestion)

The degree of prudence is an index that defines the degree to which driving of a vehicle must be carefully (lower speed) due to natural conditions for each two-dimensional area or one-dimensional road. For example, the following indicators can be cautious.
・ Current weather in the XX city area (generally, the speed of the vehicle is small in the order of snow <rain <clear, ie, snow>rain> clear).
・ Current weather from the ◎◎ intersection to the □□ intersection

(Probe cycle)
The route identification device changes the probe period to be applied according to the road density, the congestion degree, and the cautiousness. Basically, if the road density is less than the threshold TH _D, the path identification unit applies the longer probe cycle. If road density is the threshold value TH _D above, the path identification unit applies a short probe cycle.

Subsidiarily, pathway identification device, when the congestion degree is large, reduce the threshold TH _D than otherwise. That is, in more cases, a shorter probe period will be applied. Path determination apparatus, when carefully large degree, to reduce the threshold value TH _D than otherwise.

(Determination of probe cycle according to road density)
The road density and the probe cycle will be described with reference to FIG. FIG. 1 is also a road map with north on the upper side. In FIG. 1, the main road 53 leads to the east-west direction. The area slightly closer to the east than the center on the north side of the main road is an urban area, and has a higher road density than other areas. In the west half of FIG. 1, the road density is relatively low. Now, it is assumed that a vehicle (automobile) equipped with a mobile terminal device is traveling from west to east, and the mobile terminal device generates probe data at predetermined time intervals. A circle mark 55 in FIG. 1 is a positioning point, which is the position information (latitude and longitude) generated by the mobile terminal device at a predetermined time interval as it is dotd on the map.

As the vehicle travels east, the distance between the circles gradually decreases. This indicates, for example, the following.
-In the western half of Fig. 1, there are few intersections and the vehicle is flowing smoothly at a relatively high speed.
-In the eastern half of Fig. 1, there are many intersections, natural traffic congestion has occurred, and the speed of the vehicle has dropped.

  In the region 52 where the road density is high, a relatively large number of positioning points exist. Therefore, even if a certain positioning point includes a positioning error, many accurate reference points can be obtained if the positioning points before and after the positioning point hardly include a positioning error, and the correct path 54 (shown by a thick solid line) It coincides with the main road 53). However, since the number of intersections is large, the vehicle may once deviate from the main road 53 and enter the city area, and then join the main road 53 again. Therefore, in order to match a route in an area where the road density is high, it is preferable that the probe period is set short enough to obtain at least one positioning point between the intersection and the next intersection. On the contrary, if at least one positioning point exists between the intersections, the route is naturally matched (details will be described later).

  On the other hand, in the area 51 where the road density is low, there are a relatively small number of positioning points. At first glance, after passing the positioning point 55, the vehicle travels east on the main road 53 for a while, then eventually changes to the side road 57 on the right in the direction of travel, and joins the main road 53 again just before entering the city area. It can be interpreted as reaching 58. There are many cases where the vehicle actually moves in this way to avoid traffic jams. For example, assume that the positioning point 56 includes a positioning error. Then, as described above, the vehicle has diverted to the side road 57 in order to avoid traffic jams, or does the vehicle appear to have deviated to the side road 57 even though the vehicle continued to travel on the main road 53? Judgment is lost.

  In general, if the road density is low and the number of intersections is small, the reference points are unlikely to be erroneously matched even if the probe period is long. Rather, in principle, it is preferable that the probe period is long from the viewpoint of reducing the processing load. However, when a measurement error occurs at a decisive timing as in the above example, it is necessary to match routes from a plurality of candidates by some method. It cannot be expected that the route will naturally be matched due to the presence of many positioning points, such as in areas with high road density (details below).

  In the present embodiment, the route identification device instructs the mobile terminal device to perform two different probe periods according to the road density. The mobile terminal device generates probe data according to the instructed probe cycle. The route identification device performs matching by two different methods corresponding to high and low road density (that is, corresponding to each probe period). That is, the route identification device sets the probe period to be short so that route search with a large processing load can be omitted in an area where the road density is high. On the other hand, the route identification device sets a long probe cycle in an area where the road density is low, reduces the processing load related to probe data generation and the like, and executes route search.

A matching method will be described with reference to FIG. The mobile terminal device generates probe data at a predetermined time point and transmits it to the route identification device. The route identification device draws _a positioning point pa on the map based on the probe data. Thereafter, the mobile terminal device generates probe data at the next predetermined time point and transmits it to the route identification device. Route identification device is to draw a positioning point p _b on the map based on the probe data. Incidentally, the positioning point p _a and the positioning point p _b is represented graphically in arrowhead shape. The vehicle is moving in the direction indicated by the arrow tip.

Positioning point p _a, in the map, and enters the interior of the block surrounded by the four road (e.g. a house or the like is in built up). Originally, the vehicle cannot travel at this point. Nevertheless, when the route identification device draws the positioning point on the map as it is, such unnaturalness occurs due to the positioning error described above. Therefore, the route identification device draws a perpendicular to each of the four roads, and sets the intersections of the road and the perpendiculars (vertical legs) as reference point candidates P _a1 , P _a2 , P _a3 and P _a4 , respectively. The vehicle would have been driving any of these four reference point candidates.

Similarly, the positioning point p _b, in the map, and enters the interior of the block surrounded by four roads. Similarly, the path identification device obtains reference point candidates P _b1 , P _b2 , P _b3 and P _b4 .

Path determination unit, a reference point corresponding to the positioning point _{p a,} determined from among the reference point candidate _{P a1, P a2, P a3} and _{P a4.} In this case, it can be said that suitable as most reference point is the shortest candidate distance between the candidate P _ai of the positioning point p _a and the reference point. Note that i = 1, 2, 3, and 4. From another viewpoint, it can be said that a candidate on a road having the smallest angle difference, which is the difference between the moving direction of the vehicle and the direction of the road, is most suitable as the reference point. The route identification device multiplies each of these distances and angle differences by a predetermined weight, obtains a sum, and sets the result as an “evaluation value”. The evaluation value is calculated for each reference point candidate. Route identification device, the out evaluation value is the smallest candidate (candidate is high rating), and the reference point P _a corresponding to the positioning point p _a. Similarly path determination device determines the reference point P _b corresponding to the positioning point p _b.

For example, it is assumed that the path identification device determines P _a4 and P _b2 as reference points. At this stage, the path from the reference point P _a4 to the reference point P _b2 has not been matched yet. In FIG. 2, there are three path candidates, which are r ₁ , r ₂ and r ₃ . There are other routes that dare to go around, but are omitted here for simplicity. The route identification device calculates an estimated required time for each of the routes r ₁ , r _2, and r ₃ . The following is an example of a method for calculating the estimated required time.

The distance between the reference point P _a4 and the reference point P _b2 on the route is divided by the speed of the vehicle immediately before reaching the reference point _Pa4 .
A plurality of required times are accumulated when an arbitrary vehicle other than the vehicle moves between the reference point P _a4 and the reference point P _b2 on the route. Then, the average value of the accumulated required time is set as the estimated required time.

Path identification unit, the probe data, the actual time required (the vehicle is, the path is the unknown, required time actually moved from the positioning point p _a to the positioning point p _b) to obtain the. Then, the route identification device subtracts the actual required time from the estimated required time, and considers the candidate having the smallest absolute value of the subtraction result as the actual route. Note that, on the assumption that the vehicle always prefers the route with the shortest required time, the route identification device may consider the candidate with the shortest estimated required time as the actual route.
Hereinafter, the process in which the path identification device matches the reference point by two methods in accordance with the length of the probe cycle will be described more dynamically.

(Matching when probe period is short)
A matching method when the probe period is shorter than a predetermined reference will be described with reference to FIG. The mobile terminal device generates probe data at time points t ₁ , t ₂ , t ₃ , t _4, and t _{5 with} a relatively short probe period (for example, every 10 seconds). If the route identification device tries to display the positioning points at each time point on the map as they are, they are represented as positioning points p ₁ , p ₂ , p ₃ , p ₄ and p ₅ (not on the road). ).

The route identification device first matches a reference point P ₁ corresponding to the positioning point p ₁ . At this time, the road including the reference point to be matched has a small angle difference between the direction and the moving direction of the vehicle, and the distance is close to the position of the vehicle. Subsequently, the path identification unit, similarly, to match the reference point P ₂ corresponding to the positioning point p _2. Further, the path identification device matches P ₃ , P ₄ and P ₅ . The probe cycle is shortened to such an extent that at least one probe data is acquired until the vehicle reaches the next intersection. Therefore, if the matching reference points P _1, a road comprising it are matched as part of the route, if matched reference point P ₂ is the road containing it are matched as part of the path. Similarly, the entire route is matched.

(Matching when probe period is long)
A matching method when the probe period is longer than a predetermined reference will be described with reference to FIG. The mobile terminal apparatus acquires probe data at time points t ₁ , t _5, and t ₉ in a relatively long probe cycle (for example, every 40 seconds). If the route identification device tries to display the positioning points at each time point on the map as they are, they are represented as positioning points p ₁ , p ₅ and p ₉ (not on the road).

The route identification device first matches a reference point P ₁ corresponding to the positioning point p ₁ . Next, the route identification device, similarly, to match a reference point P ₅ corresponding to the positioning point p _5. The method of matching the reference points at these times is the same as the example of FIG. Unlike the example of FIG. 3 (a), the path from the reference point P ₁ to the reference point P ₅ is naturally not matched. This is because the probe cycle is long, so that it is not always guaranteed that at least one probe data is acquired until the vehicle reaches the next intersection. That is, the movement at the intersection of the vehicle becomes unclear.

Therefore, the route identification device matches the most suitable route among the _three route candidates r ₁ , r _2, and r ₃ . The matching here is performed by comparing the estimated required time of the route candidate with the actual required time as described above.

Thereafter, the path identification unit, matching the reference point P ₉ corresponding to the positioning point p _9. Further, after that, the path identification device matches the most suitable path among the three path candidates r ₄ , r ₅ and r ₆ .

Hereinafter, the contents of information processing performed by the route identification device will be described more generally and mathematically.
Now, it is assumed that the positioning point p is in an n-square block surrounded by n roads. A perpendicular is drawn from the positioning point for each of the sides of the n-gon. Then, the perpendicular foot P is the point having the shortest distance from the positioning point among the points included in the side. n perpendicular legs are set, each of which is called a “reference point candidate” P _i . Note that i = 1, 2, 3,..., N. θ is the direction in which the vehicle moves at the positioning point. Θ _i is the direction of the road where the i th reference point exists.

d _i (p, P _i ) is a distance between the positioning point p and the i th reference point candidate P _i . g _i (θ, Θ _i ) is an angle difference between the direction in which the vehicle moves at the positioning point p and the direction of the road to which the i th reference point candidate P _i belongs. In the present embodiment, θ can take one value in the range of 0 to 360 degrees, whereas Θ _i has two values in the range of 0 to 360 degrees (for example, 50 degrees when the road is not one-way). And 230 degrees). Now, these two values are represented as Θ _1i and Θ _2i . Then, g _i (θ, Θ _i ) here is the smaller of the angular difference between θ and Θ _1i and the angular difference between θ and Θ _2i, and takes a range of 0 to 90 degrees. On the other hand, if the road is one-way, Θ _i takes a single value (eg, 135 degrees) in the range of 0 to 360 degrees. Then, g _i (θ, Θ _i ) here is simply an angle difference between θ and Θ _i and takes a range of 0 to 180 degrees.

Now, there are two positioning points p _a and p _b obtained in succession, each of the reference points P _a and P _b corresponding to the two positioning points already to have been matched. Assume that there are m paths between two reference points. Each of them is called a “route candidate” r _j . J = 1, 2, 3,..., M. _{t j (p a, p b} , r j) is the estimated time to reach the reference point _{P b,} which via a route _{r j} from the reference point _{P a} corresponding to the positioning point _{p a} corresponds to the positioning point _{p b} , the actual and required time that led from the positioning point p _a to the positioning point p _b, which is the difference.

When the probe period is shorter than the predetermined reference, the path identification device matches the reference point without causing the path. Specifically, the route identification device obtains “i” that minimizes the following F ₁ (i).
F ₁ (i) = αd _i (p, P _i ) + β g _i (θ, Θ _i )
Here, α and β are weights multiplied by d _i (p, P _i ) and g _i (θ, Θ _i ), respectively, and α + β = 1, 0 ≦ α ≦ 1, and 0 ≦ β ≦. 1 is true. When the route identification device repeats this process for the number of positioning points, the reference points corresponding to the positioning points are successively matched.

The path identification device performs the following processing when the probe cycle is longer than the predetermined reference.
(1) First, the path identification device obtains “i” for minimizing the aforementioned F ₁ (i) for the first reference point. That is, the positioning point is matched with the reference point.
(2) The route identification device obtains “i” that minimizes F ₁ (i) described above for the second reference point.
(3) The route identification device obtains “j” that minimizes the following F ₂ (j) for the route between the first reference point and the second reference point. That is, a route that is considered to have actually moved from among a plurality of route candidates is matched.
F ₂ (j) = t _j (p _a , p _b , r _j )

(4) The route identification device obtains “i” that minimizes F ₁ (i) described above for the third reference point.
(5) The path identification device obtains “j” that minimizes the aforementioned F ₂ (j) for the path between the second reference point and the third reference point.
(6) Thereafter, the route identification device repeats the processes (4) and (5).

  In the above description, for the sake of easy understanding, the example in which the route identification device sequentially matches the reference point and the route has been described. However, the path identification device may determine all reference points and paths simultaneously. That is, the route identification device may obtain “i” and “j” simultaneously so as to minimize the following F (i, j). The number of “i” obtained here is equal to the number of positioning points, and the number of “j” obtained is equal to the number of positioning points−1.

F (i, j) = Σαd _i (p, P _i ) + Σβg _i (θ, Θ _i ) + Σγt _j (p _a , p _b , r _j )
The first term on the right side is a weighted sum of d, and the number of d added after multiplying by the weight α is equal to the number of positioning points. The second term on the right side is a weighted sum of g, and the number of g added after multiplying by the weight β is equal to the number of positioning points. The third term on the right side is a weighted sum of t when the probe period is long, and the number of t added after multiplying by the weight γ is equal to the number of positioning points minus one. γ is a weight multiplied by t _j (p _a , p _b , r _j ), and α + β + γ = 1, 0 ≦ α ≦ 1, 0 ≦ β ≦ 1, and 0 ≦ γ ≦ 1 hold. Yes.

(Route identification device)
The configuration of the route identification device will be described with reference to FIG. The route identification device 1 is a general computer. The path identification device 1 includes a central control device 11, an input device 12, an output device 13, a main storage device 14, an auxiliary storage device 15, and a communication device 16. These are connected by a bus. The auxiliary storage device 15 stores probe data 31 and map data 32. The probe data receiving unit 21, the probe data determining unit 22, the probe data collection condition setting unit 23, and the matching unit 24 in the main storage device 14 are programs. In the following description, when the operation subject is described as “XX part”, it means that the central control unit 11 reads the XX part from the auxiliary storage device 15 and loads it into the main storage device 14 and then loads the XX part. It means to realize the function (detailed later).

  The path identification device 1 is connected to the probe data collection server 3 via the network 5 and is also connected to the external server 4. The probe data collection server 3 can communicate with the mobile terminal device 2 by wireless communication technology. The probe data collection server 3 can transfer probe data generated by the mobile terminal device 2 to the route identification device 1 in real time, or temporarily accumulates probe data and transmits it to the route identification device 1 at an arbitrary timing. You can also

  The external server 4 is a server operated by a public office or the like, and stores traffic information, weather information, and the like. The route identification device 1 can acquire the degree of congestion and the cautiousness described later from the external server 4. Moreover, the external server 4 can receive the matched route from the route identification device 1 and further enhance the traffic information and the like stored in itself.

  The mobile terminal device 2 is a computer for car navigation, for example, and includes an input / output device 35 and a main storage device 36. The navigation unit 41 and the probe data generation unit 42 in the main storage device 36 are programs. In the following description, when the operation subject is described as “XX part is”, it means that the central control unit (not shown) reads the XX part from the auxiliary storage device (not shown) and loads it into the main storage device 36. This means that the function of the part (detailed later) is realized. The route identification device 1 and the mobile terminal device 2 constitute a route identification system.

(Processing procedure)
A processing procedure will be described with reference to FIG.
In step S201, the navigation unit 41 of the mobile terminal device 2 notifies the departure place and the destination. Specifically, first, the navigation unit 41 accepts that the user inputs a starting point and a destination via the input / output device 35. The navigation unit 41 obtains the map data 32 from the route identification device 1 in advance and displays it on the input / output device 35, and the user selects a departure place and a destination on the map data 32 (on the screen). Touching with a finger) may be accepted.
Secondly, the navigation unit 41 transmits the position information of the departure place and the position information of the destination to the route identification device 1.

  In step S202, the navigation unit 41 requests a planned route. Specifically, when the navigation unit 41 accepts that the user presses a “planned route” button via the input / output device 35, the navigation unit 41 transmits a “planned route transmission request” to the route identification device 1.

  In step S203, the probe data collection condition setting unit 23 of the route identification device 1 acquires the map data 32. Specifically, the probe data collection condition setting unit 23, based on the departure point and destination transmitted in step S201, from the auxiliary storage device 15 to the planned route from the departure point to the destination (details will be described later). Is acquired.

  In step S204, the probe data collection condition setting unit 23 identifies a planned route. Specifically, the shortest route from the departure point to the destination is drawn on the map data 32 acquired in step S203 by a known method, and this is set as a “scheduled route”. In addition, the curve with the arrow of FIG. 6 is a schedule path | route.

  In step S205, the probe data collection condition setting unit 23 determines a probe cycle. Specifically, first, the probe data collection condition setting unit 23 divides the map data 32 into a plurality of mesh-like regions. Then, each area (dotted area in FIG. 6) through which the planned route passes and each of the surrounding areas (hatched area in FIG. 6) are set as “attention areas”.

Second, the probe data collection condition setting unit 23 calculates a standard threshold value. The standard threshold is, for example, a value obtained by dividing the number of intersections existing in all areas on the map including the attention area by the number of all areas. As a matter of course, the standard threshold value is a common value for each region of interest.
Thirdly, the probe data collection condition setting unit 23 counts and acquires the above-described road density (for example, the number of intersections in the region) for each region of interest.
Fourth, the probe data collection condition setting unit 23 acquires the degree of congestion and the alertness for each region of interest from the external server 4.

Fifth, the probe data collection condition setting unit 23 corrects the road density threshold based on the degree of congestion and the alertness for each region of interest. The corrected threshold value is defined for each region of interest. For example, it is assumed that the standard threshold is “TH”. Now, it is assumed that the congestion degree of the attention area A is a% larger than the predetermined reference value, and the alertness degree of the attention area A is b% larger than the predetermined reference value. Then, the probe data collection condition setting unit 23 sets the value of TH × (100−a) / 100 × (100−b) / 100 as the corrected threshold value “TH _A ” of the attention area.
The probe data collection condition setting unit 23 repeats “third” to “fifth” in step S205 for every region of interest. At the stage where the repetitive processing is completed, the probe data collection condition setting unit 23 holds a corrected threshold value for each region of interest.

  Sixth, the probe data collection condition setting unit 23 determines the length of the probe cycle for each region of interest. If the road density of a certain region of interest is less than the corrected threshold value of the region of interest, the probe data collection condition setting unit 23 gives “long” to the region of interest. If the road density of a certain region of interest is equal to or higher than the corrected threshold value of the region of interest, the probe data collection condition setting unit 23 gives “short” to the region of interest. “Long” indicates that a long probe period (second period) is applied in the region of interest. “Short” indicates that a short probe period (first period) is applied in the region of interest. Note that the probe data collection condition setting unit 23 holds a specific cycle (for example, 1 minute) indicated by “long” and a specific cycle (for example, 20 seconds) indicated by “short”.

As a result, the probe data collection condition setting unit 23 generates the following probe cycle instruction information.
(1,1, short), (1,2, short), (1,3, long), (2,1, long), ...,
(2,2, short), ..., (3,3, long), (3,4, short), ..., (12,14, short)
The probe cycle instruction information is made up of “(,,)” equal to the number of regions of interest, the first component of which is the row in FIG. 6 and the second component is the column in FIG. Show.

  In step S206, the probe data collection condition setting unit 23 notifies the planned route and the probe cycle. Specifically, the probe data collection condition setting unit 23 transmits to the mobile terminal device 2 the planned route identified in step S204 and the probe cycle instruction information generated in “sixth” in step S205. Thereafter, the vehicle equipped with the mobile terminal device 2 departs from the departure point toward the destination.

  In step S207, the probe data generation unit 42 of the mobile terminal device 2 generates probe data. Specifically, the probe data generation unit 42 generates probe data according to the probe cycle instruction information. For example, during a period in which the vehicle is in the region of interest (2, 2) in FIG. 6, the probe data generation unit 42 generates probe data with a short probe cycle. Thereafter, when the vehicle enters the region of interest (3, 3) in FIG. 6, the probe data generation unit 42 generates probe data with a long probe cycle. Furthermore, when the vehicle enters the region of interest (3,4) in FIG. 6, the probe data generation unit 42 generates probe data again with a short probe cycle. It is assumed that the vehicle arrives at the destination while the probe data generation unit 42 generates the probe data in this way. At this stage, the probe data is a lot of time-series position information, and each piece of position information indicates a positioning point.

In step S208, the probe data generation unit 42 transmits probe data. Specifically, the probe data generation unit 42 transmits periodic probe data to the path identification device 1. Periodic probe data is the following data.
(X ₁ , y ₁ , long, 20160506 10:00:00), (x ₂ , y ₂ , long, 20160506 10:01:00),
_{(X 3, y 3,} length, 20160506 10:02:00), ...,
_{(X 101, y 101, short, 20160506 11:00:00), (x 102} , y 102, _{short, 20160506 11:00:20), (x 103} , y 103, short, 20160506 11:00:40) , ...

The periodic probe data indicates, for example, the following.
-The vehicle is operated during the period from 10:00:00 on May 6, 2016 to 11:00:40, positioning points (x ₁ , y ₁ ), (x ₂ , y ₂ ), (x ₃ , y _3), ···,
(X ₁₀₁ , y ₁₀₁ ), (x ₁₀₂ , y ₁₀₂ ), (x ₁₀₃ , y ₁₀₃ ),. x is latitude and y is longitude.
The vehicle first traveled in the region of interest where the long probe period was applied, and then traveled in the region of interest where the short probe period was applied.

A long probe cycle is applied from the positioning point (x ₁ , y ₁ ) to (x ₃ , y ₃ ), and as a result, probe data is acquired every minute.
A short probe cycle is applied from the positioning point (x ₁₀₁ , y ₁₀₁ ) to (x ₁₀₃ , y ₁₀₃ ), and as a result, probe data is acquired every 20 seconds.

  In step S209, the probe data reception unit 21 of the path identification device 1 acquires the probe data 31. Specifically, the probe data receiving unit 21 acquires the probe data 31 from the mobile terminal device 2 and stores it in the auxiliary storage device 15.

In step S210, the probe data determination unit 22 of the path identification device 1 determines the probe period. Specifically, referring to the periodic probe data 31 transmitted in step S208, the time point when the probe period changes from “long” to “short” or from “short” to “long” is specified.
Even if the periodic probe data does not have “short” and “long”, the probe data discriminating unit sets the time interval such as “20160506 10:00:00” to the “number” in step S205. The probe period can be determined by making it correspond to the period held at 6 ″.

  In step S211, the matching unit 24 of the route identification device 1 matches routes. Since the details of the processing in this step have been described above, only the main points are repeated here. The matching unit 24 repeats the process of matching the reference point with the positioning point for each positioning point in the region of interest with a short probe cycle. At this time, if the positioning point is matched with the reference point, the route is uniquely determined without special processing. In other words, the matching unit 24 matches the positioning point to the reference point that the mobile terminal device has actually moved, and considers that the mobile terminal device has actually moved the road on the map to which the reference point belongs. Part of the deceived route.

  On the other hand, the matching unit 24 repeats the process of matching the reference point with the positioning point in the region of interest having a long probe cycle, and then matching the route between the reference point and the previous reference point. . That is, the matching unit 24 matches the positioning point to the reference point, and matches the route that the mobile terminal device is considered to have actually moved from among a plurality of route candidates that connect the plurality of reference points. .

In step S212, the matching unit 24 of the route identification device 1 transmits the matched result. Specifically, first, the matching unit 24 transmits the matching result to the mobile terminal device 2. The matching result is data for displaying a plurality of reference points and routes superimposed on map data. Thereafter, in the vehicle, the user can verify whether or not the route actually traveled matches the matching result.
Secondly, the matching unit 24 transmits the matching result to the external server 4. The government office can accumulate many matching results transmitted in this way, and use it as a material for planning city plans and the like.
Thereafter, the processing procedure is terminated.

  In the above processing procedure, an example has been described in which the mobile terminal device 2 collectively transmits probe data from the departure point to the destination after the vehicle has arrived at the destination, to the route identification device 1. However, the mobile terminal device 2 may transmit a part of the probe data at an arbitrary timing during traveling, or may transmit the probe data at a time point in real time. In response to this, the route identification device 1 may match a route at an arbitrary timing during traveling, or may match a reference point (and a route) at a time point in real time.

(Method of not receiving probe cycle indication information)
In the above description, the mobile terminal device 2 has received the probe cycle instruction information from the path identification device 1 and described an example in which the probe cycle is changed according to the received probe cycle instruction information. However, an example in which the mobile terminal device 2 does not receive the probe cycle instruction information is also possible. In this case, it can be assumed that the mobile terminal device 2 changes the probe cycle based on its own judgment and the mobile terminal device 2 always maintains a constant probe cycle.

(Example in which the mobile terminal device changes the probe period based on its own judgment)
The probe data determination unit 22 of the path identification device 1 detects the time interval of the received probe data 31 and compares it with a predetermined threshold value. If the interval is less than the threshold value as a result of the comparison, the probe data determination unit 22 considers that the probe cycle is short and processes the probe data. When the interval is equal to or greater than the threshold, the probe data determination unit 22 processes the probe data by regarding that the probe cycle is long.

(Example where the mobile terminal device always maintains a constant probe period)
The probe data discriminating unit 22 of the route identification device 1 detects a positioning point of the received probe data 31 and identifies a region of interest where the vehicle is currently traveling. The probe data discriminating unit 22 does not transmit the probe cycle instruction information and holds it in its main storage device 14, and refers to the probe cycle instruction information, so that the current attention area is “short” or “ Judge whether it falls under “long”. And the probe data discrimination | determination part 22 processes probe data based on the judgment result.

(Road density map)
In the above description, the example in which the route identification device 1 counts and acquires the road density for each region of interest has been described. However, the route identification device 1 may store a road density map in which the road density is stored in advance in association with all the regions of the map data 32 in the auxiliary storage device 15.

(Time period and distance period)
The probe data collection condition setting unit 23 of the path identification device 1 calculates the speed at which the mobile terminal device 2 moves from the received probe data, and sets the probe period as a time period according to the calculated speed, You may determine whether it is set as a distance period. For example, when the speed is smaller than a predetermined threshold, the probe period may be a distance period, and when the speed is not less than a predetermined threshold, the probe period may be a time period.

  Further, the probe data collection condition setting unit 23 receives the congestion level or the alertness level of the attention area from the external server 4, and sets the probe cycle as a temporal cycle according to the received congestion level or the alertness level, Whether to use a distance period may be determined for each region of interest. For example, when the degree of congestion is larger than a predetermined threshold, the probe period may be a distance period, and when the degree of congestion is not more than a predetermined threshold, the probe period may be a time period. When the prudence level is greater than a predetermined threshold, the probe cycle may be a distance cycle, and when the prudence level is less than or equal to a predetermined threshold, the probe cycle may be a time cycle.

(Target for defining road density)
In general, information from the external server 4 is obtained for each area (for example, “20 cm of snow in Tokyo 23 wards”) and information obtained for each road (for example, “Circular ○ Line is due to an accident ◎◎ □□ km traffic jam ”) at the beginning of the intersection. Therefore, the probe data collection condition setting unit 23 may not only calculate and correct the road density for each region of interest, but may also calculate and correct the road density for each road or each road section.

(Matching without road density)
The matching unit 24 may change the matching method simply in accordance with the length of the probe period regardless of the road density. For example, if the interval between a certain positioning point and the immediately preceding positioning point is shorter than a predetermined threshold, the matching unit matches the positioning point by a method when the probe cycle is short. If the interval between a certain positioning point and the previous positioning point is equal to or greater than a predetermined threshold, the matching unit matches the positioning point by a method in which the probe period is long, and then matches the route. That is, the matching unit 24 determines which method to use “every step”.

(Effect of this embodiment)
The effects of the route identification device of the present embodiment are as follows.
(1) Since the path identification device matches paths according to the probe period, the processing load is reduced.
(2) The path identification device does not perform path matching when the probe period is short, and reduces the processing load by reducing the number of times probe data is generated when the probe period is long.
(3) Since the route identification device calculates the road density for each region on the map and changes the probe cycle according to the calculated road density, the processing burden is reduced according to the specific planned route of the vehicle. Can do.

(4) Since the route identification device matches the reference point corresponding to the positioning point based on the distance and the angle difference, and matches the route based on the required time of the route candidate, the matching accuracy is ensured.
(5) The route identification device corrects the threshold value applied to the road density when determining the probe period according to the degree of congestion and prudence, so matching regardless of changes in traffic conditions, natural conditions, etc. Accuracy is guaranteed.
(6) Since the route identification device determines the probe period for a part of the map on the basis of the starting point and the destination, it is possible to avoid useless information processing.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
In addition, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. In practice, it may be considered that almost all the components are connected to each other.

DESCRIPTION OF SYMBOLS 1 Path | route identification device 2 Mobile terminal device 3 Probe data collection server 4 External server 5 Network 11 Central control device 12 Input device 13 Output device 14 Main storage device 15 Auxiliary storage device 16 Communication device 21 Probe data reception part 22 Probe data discrimination | determination part 23 Probe data collection condition setting unit 24 Matching unit 31 Probe data 32 Map data 35 Input / output device 36 Main storage device 41 Navigation unit 42 Probe data generation unit

Claims (10)

A probe data receiving unit that receives probe data that is a time-series movement trajectory of the mobile terminal device from the mobile terminal device;
A matching unit that matches a route that the mobile terminal device is considered to have actually moved in a different method corresponding to a period in which the probe data is generated;
A path identification device comprising: The matching unit is
When the period is shorter than a predetermined reference, the positioning point included in the probe data is matched with a reference point that the mobile terminal device is actually moved on a map, and the reference point A road on the map to which the mobile terminal device is considered to be part of the route considered to have actually moved,
When the period is longer than a predetermined reference, the mobile terminal apparatus actually matches the positioning point with the reference point and the plurality of route candidates connecting the reference points. Matching routes that are considered to have moved,
The route identification device according to claim 1, wherein: Calculate the density of roads in the area on the map where the mobile terminal device moves, for each area,
Depending on the calculated road density, the probe data should be generated in a first period, or the probe data should be generated in a second period longer than the first period. A probe data collection condition setting unit that determines for each region and instructs the mobile terminal device;
The route identification device according to claim 2, wherein: The matching unit is
When the probe data is generated in the first cycle, the distance between the positioning point and the reference point candidate, the direction in which the mobile terminal device moves at the positioning point, and the reference point candidate are Based on the angle difference from the direction of the road to which it belongs, the positioning point is matched with the reference point,
When the probe data is generated in the second period, the positioning point is matched with the reference point based on the distance and the angle difference, and the route is matched based on the required time of the route candidate. To do,
The route identification device according to claim 3. The probe data collection condition setting unit
When determining the period in which the probe data should be generated, a threshold value serving as a reference for determining the length of the period is applied to the density of the road,
Correcting the threshold value based on congestion and natural conditions;
The route identification device according to claim 4. The probe data collection condition setting unit
From the mobile terminal device, a starting point and a destination are received,
Determining a period for generating the probe data for a part of the area on the map based on the received starting point and destination;
The route identification device according to claim 5. A mobile terminal device that transmits probe data that is its own time-series movement trajectory to the route identification device;
Receiving the probe data;
The route identification device for matching a route that the mobile terminal device is considered to have actually moved by a different method corresponding to a period in which the probe data is generated;
A route identification system comprising: The route identification device includes:
When the period is shorter than a predetermined reference, the positioning point included in the probe data is matched with a reference point that the mobile terminal device is actually moved on a map, and the reference point A road on the map to which the mobile terminal device is considered to be part of the route considered to have actually moved,
When the period is longer than a predetermined reference, the mobile terminal apparatus actually matches the positioning point with the reference point and the plurality of route candidates connecting the reference points. Matching routes that are considered to have moved,
The route identification system according to claim 7. The probe data receiver of the route identification device
Receiving probe data that is a time-series movement trajectory of the mobile terminal device from the mobile terminal device;
The matching unit of the route identification device is
Matching a path that the mobile terminal device is considered to have actually moved in a different manner corresponding to the period in which the probe data is generated;
A path identification method for a path identification device characterized by the following. The matching unit is
When the period is shorter than a predetermined reference, the positioning point included in the probe data is matched with a reference point that the mobile terminal device is actually moved on a map, and the reference point A road on the map to which the mobile terminal device is considered to be part of the route considered to have actually moved,
When the period is longer than a predetermined reference, the mobile terminal apparatus actually matches the positioning point with the reference point and the plurality of route candidates connecting the reference points. Matching routes that are considered to have moved,
The route identification method according to claim 9.

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