JP5600054B2 - Accompanying judgment apparatus, mobile terminal and program for estimating accompanying state of plural mobile terminals - Google Patents

Description

  The present invention relates to a technique for estimating the accompanying state of a plurality of mobile terminals.

  In recent years, mobile terminals (for example, mobile phones and smartphones) equipped with a positioning unit such as GPS (Global Positioning System) have become widespread. The user who operates the mobile terminal can measure his / her position by the positioning unit and can also record a movement history corresponding to the passage of time. Using these movement histories, it can also be determined whether or not the user is traveling with another mobile terminal. By using the determination result, various services can be provided to the user.

  Conventionally, in order to estimate the accompanying state of a plurality of mobile terminals, there is a technique for calculating a distance from position information at the same time for two mobile terminals and determining whether the distance is equal to or less than a predetermined threshold ( For example, see Patent Document 1.) According to this technique, since GPS is used, measurement errors are often included in places where the line of sight is poor with respect to the sky. Thereby, the estimation accuracy of the accompanying state of the mobile terminal also decreases. In particular, in the movement history, good / bad measurement accuracy is mixed depending on the location, and determining the distance between the mobile terminals with a threshold value further adversely affects the estimation accuracy of the accompanying state.

  On the other hand, in addition to the distance between mobile terminals, there is also a technique that uses an error distance calculated at each position based on the measurement accuracy of the positioning unit (see, for example, Patent Document 2). According to this technique, the total value of error distances is defined as a combined error distance, and the degree of accompaniment is calculated based on the distance between mobile terminals and the combined error distance, and the degree of accompaniment and the combined error distance are compared with a predetermined threshold value. The accompanying state is determined.

JP 2004-118290 A JP 2010-96633 A

  However, according to the technique described in Patent Document 2, this technique cannot be used when the measurement accuracy is unknown. In addition, there is a characteristic that it is determined that “suspicious is accompanied”. This characteristic means that if the ratio of the measurement error to the relative distance is large, “it is likely to accompany”. In other words, as the measurement error increases, the accompanying or non-accompanying boundary (threshold) moves in favor of “accompanying”. This characteristic contributes to the accuracy of being determined to be “accompanying” when accompanied, but may be determined to be “accompanying” when not accompanying.

Accordingly, the present invention may be unknown measurement error of the mobile terminal, accompanied determining apparatus for travel condition can be accurately estimated in a plurality of mobile terminals, and to provide a mobile terminal and program .

According to the present invention, there is a accompanying determination device for storing position information of a mobile terminal at each time and estimating the accompanying state of a plurality of mobile terminals,
For a given azimuth, the traveling azimuth theta _t-1 at previous time, variation calculating a heading angle theta _t at the current time, the magnitude of the difference between the advancing azimuth angle theta _t-1 and the traveling azimuth theta _t Variation angle calculating means for calculating the angle Δθ _t ,
A peak time point extracting means for extracting a peak time point at which the fluctuation angle Δθ _t fluctuates more than a predetermined threshold value from increase to decrease;
A curve section determination unit that extracts a linear movement section having a minimum time τ or more between peak time points and determines a curve section when three or more linear movement sections are continuous;
A traveling azimuth difference extraction means for comparing the curve section of the first mobile terminal and the curve section of the second mobile terminal and extracting the difference of the traveling azimuth angle θ at the same time;
The first mobile terminal and the second mobile terminal have a trajectory similarity determination unit that determines that the trajectory is similar when the variance of the difference in the traveling azimuth angle θ is equal to or less than a threshold value. The first mobile terminal and the second mobile terminal are estimated to be in the “accompanying” state.

  According to another embodiment of the accompanying determination apparatus of the present invention, it is also preferable that the curve section determination means further extracts only a linear movement section within the maximum time T.

  According to another embodiment of the accompanying determination device of the present invention, when it is not determined that the trajectory is similar, the distance between the first mobile terminal and the second mobile terminal is determined, and the distance is more than a predetermined threshold. It is also preferable to further include a tracking unit that determines that the user is “not accompanied”.

According to the present invention, a mobile terminal equipped with the accompanying determination device described above,
A positioning unit for positioning the current position information;
A communication interface unit that receives position information of the counterpart mobile terminal from the counterpart mobile terminal or server;
Only when the location information of the local mobile terminal output from the positioning unit and the location information of the counterpart mobile terminal output from the communication interface unit are moving according to the passage of time, the local mobile terminal It is also preferable to further include position estimation means for outputting the position information of the mobile terminal and the position information of the counterpart mobile terminal to the fluctuation angle calculation means.

According to another embodiment of the mobile terminal of the present invention,
The trajectory similarity determining means outputs the difference in traveling azimuth to the position estimating means when the local mobile terminal and the counterpart mobile terminal are determined to be similar to the trajectory,
The position estimating means preferably includes the difference in the traveling azimuth as an offset in the position information of the counterpart mobile terminal relative to the position information of the local mobile terminal.

According to the present invention, the accompaniment determination program for storing the position information of the mobile terminal at each time and for causing the computer mounted on the apparatus for estimating the accompany state of the plurality of mobile terminals to function.
For a given azimuth, the traveling azimuth theta _t-1 at previous time, variation calculating a heading angle theta _t at the current time, the magnitude of the difference between the advancing azimuth angle theta _t-1 and the traveling azimuth theta _t Variation angle calculating means for calculating the angle Δθ _t ,
A peak time point extracting means for extracting a peak time point at which the fluctuation angle Δθ _t fluctuates more than a predetermined threshold value from increase to decrease;
A curve section determination unit that extracts a linear movement section having a minimum time τ or more between peak time points and determines a curve section when three or more linear movement sections are continuous;
A traveling azimuth difference extraction means for comparing the curve section of the first mobile terminal and the curve section of the second mobile terminal and extracting the difference of the traveling azimuth angle θ at the same time;
For the first mobile terminal and the second mobile terminal, when the variance of the difference in the traveling azimuth angle θ is equal to or less than the threshold, the computer functions as a trajectory similarity determination unit that determines that the trajectory is similar, and the trajectory is determined to be similar. The first mobile terminal and the second mobile terminal are estimated to be in the “accompanying” state.

Bank determination apparatus of the present invention, according to the mobile terminal and program, even unknown measurement error of the mobile terminal, it is possible to accurately estimate the travel state in a plurality of mobile terminals.

It is explanatory drawing showing the accompanying state in a some mobile terminal. It is a functional block diagram of the accompanying estimation apparatus in this invention. It is explanatory drawing showing the fluctuation angle of the travel azimuth angle in a mobile terminal. It is a graph showing a peak time. It is a graph showing the time of a continuous peak. It is explanatory drawing showing the difference (phi) of the advancing azimuth in a curve area. It is a graph showing dispersion | distribution of the difference (phi) of the advancing azimuth angle in two mobile terminals. It is a function block diagram of the mobile terminal in this invention. It is explanatory drawing of the offset in a position estimation part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram showing the accompanying state in a plurality of mobile terminals.

  The mobile terminal 1 has a positioning function, and can acquire the current position by receiving positioning radio waves from the GPS satellite 2. The position information can be transmitted to the accompanying estimation device and other mobile terminals via the network.

  According to FIG. 1, the walking state in the users a to c possessing the mobile terminals A to C is represented. Here, user a and user b are in the accompanying state, but only user c is not in the accompanying state. “Accompanying state” means a state in which a plurality of users are moving together. Therefore, a plurality of users in the accompanying state have the same movement locus.

  It can be applied to various services by determining the accompanying state of a plurality of users. For example, even if the user moves without entering the field of view, the user who owns one mobile terminal can know whether or not the user who owns the other mobile terminal is accompanied together. Such movement is not limited to walking, but may be traveling of a vehicle. Further, a plurality of mobile terminals in the accompanying state can be extracted by using a position information database in which movement trajectories of a large number of mobile terminals are accumulated.

  FIG. 2 is a functional configuration diagram of the accompanying estimation apparatus according to the present invention.

According to FIG. 2, the accompanying estimation apparatus 1 estimates the accompanying state of a plurality of mobile terminals, and accumulates position information for each time in a communication interface 101 connected to the network and a large number of mobile terminals. And a position information database 102. The location information database 102 stores a mobile terminal identifier, time, and location information in association with each other.
Mobile terminal identifier <-> Time <-> Location information

  Further, according to FIG. 2, the accompanying estimation device 1 includes a fluctuation angle calculation unit 111, a peak time point extraction unit 112, a curve segment determination unit 113, a traveling azimuth angle difference extraction unit 114, and a trajectory similarity determination unit 115. A tracking unit 116 and an application processing unit 120. These functional components are realized by executing a program that causes a computer installed in the accompanying estimation apparatus 1 to function. Further, the signal flow of each functional component is recognized as a processing method in the accompanying estimation device.

Change angle calculation unit 111, for a given orientation, the traveling azimuth theta _t-1 at the preceding time, and calculates the traveling azimuth theta _t at the current time, the traveling azimuth theta _t-1 and the traveling azimuth theta _t The variation angle Δθ _t that is the magnitude of the difference is calculated.

  FIG. 3 is an explanatory diagram showing the variation angle of the traveling azimuth angle in the mobile terminal.

  According to FIG. 3, “north” is used as a reference as a predetermined direction. For each time, the traveling azimuth angle θ with respect to the predetermined azimuth “north” is calculated. The traveling azimuth angle θ can be derived by comparing position information at the previous time with position information at the current time.

  Here, the position information may be absolute positioning using GPS, or may be relative positioning (dead reckoning). The position information database 102 stores position information of absolute positioning or relative positioning. In any method, the traveling azimuth angle with respect to the predetermined azimuth “north” can be derived.

The fluctuation angle calculation unit 111 calculates the fluctuation angle Δθ _t by the following equation.
Δθ _t = arccos (sinθ _t · sinθ _t-1 + cosθ _t · cosθ _t-1 ) (0 ≦ Δθ _t ≦ 180)
θ _t : Traveling direction azimuth at time t θ _t-1 : Traveling direction azimuth at time t-1 The traveling azimuth is represented by 0 ° to 359 ° clockwise with respect to a predetermined azimuth. It is calculated by the formula of

The peak time point extraction unit 112 extracts a peak time point when the fluctuation angle Δθ _t has fluctuated more than a predetermined threshold value from increase to decrease. “Peak time point” means that the vehicle is bent at that point in the movement trajectory.

  FIG. 4 is a graph showing the peak time point.

According to the graph of FIG. 4, the variation angle Δθ _t corresponding to the passage of time is represented. Here, the peak time point when the fluctuation angle Δθ _t fluctuates by a predetermined threshold value or more is shown.

  The curve section determination unit 113 extracts a linear movement section having a minimum time τ or more between peak points, and determines that it is a curve section when three or more linear movement sections continue. Here, it is also preferable to extract only the linear movement section that is not less than the minimum time τ and within the maximum time T. By defining the minimum time τ, frequent curve sections are not extracted as candidates. This eliminates the complexity of candidate data. Further, by defining the maximum time T, a curve section that contains only a straight line is not extracted as a candidate. Thus, the accompanying state is not detected using only a single curve section.

  FIG. 5 is a graph showing successive peak time points.

The peak-to-peak interval is called the “linear movement section”. Assuming that the timing at the i-th peak time is t _i , the length d _i of the i-th linear movement section is expressed as follows.
d _i = t _i −t _i−1
At this time, the truth value is_curve representing the curve is expressed as follows.
is_curve = true ((τ <d _i-2 <T) ∧ (τ <d _i-1 <T) ∧ (τ <d _i <T))
false (otherwise)
As shown in FIG. 5, for each mobile terminal, a curve section is determined in units of three linear movement sections connected by four peak points.

The traveling azimuth difference extraction unit 114 compares the curve section of the first mobile terminal with the curve section of the second mobile terminal, and extracts the difference of the traveling azimuth angle θ at the same time. Here, the difference in the traveling azimuth at the same time is calculated by the following equation. The travel direction azimuth difference φ is calculated at all times within the curve section.
Traveling azimuth angle of the first mobile terminal: θ _A
Traveling azimuth angle of the first mobile terminal: θ _B
Advancing azimuth difference φ
When | θ _A −θ _B | ≦ 180, φ = θ _A −θ _B (a)
When θ _A −θ _B > 180, φ = (θ _A −θ _B ) −360 (b)
(-180 ≦ φ ≦ 180)
When θ _A −θ _B <−180, φ = (θ _A −θ _B ) +360 (c)

  FIG. 6 is an explanatory diagram showing a difference φ in the traveling azimuth angle in the curve section.

FIG. 6A represents the above (Formula a). Here, there is a relationship of | θ _A −θ _B | ≦ 180, and the difference φ is represented by θ _A −θ _B.
FIG. 6B represents the above (Formula b). Here, in the relationship of θ _A −θ _B > 180, the difference φ is represented by (θ _A −θ _B ) -360.
FIG. 6C illustrates the above (Formula c). Here, in the relation of θ _A −θ _B <−180, the difference φ is represented by (θ _A −θ _B ) +360.

  By comparing the traveling azimuth angles in the curve sections based on the movement trajectory of each mobile terminal, the accompanying state between the mobile terminals is estimated. That is, it can be determined that the mobile terminals having similar curve sections are likely to be in the accompanying state as time passes. On the other hand, it can be determined that mobile terminals that do not have similar curve sections may not be in the accompanying state. According to the present invention, when there is no curve section in the movement locus (only in the case of a straight section), the relative distance is calculated by the tracking unit 116, and the accompanying state is determined based on the distance.

  The trajectory similarity determination unit 115 determines “trajectory similarity” for the first mobile terminal and the second mobile terminal when the variance of the traveling azimuth difference φ is equal to or less than a predetermined threshold Ψ. The “trajectory similarity” means that the first mobile terminal and the second mobile terminal are in the “accompanying” state.

  FIG. 7 is a graph showing the variance of the difference φ of the traveling azimuth angle between the two mobile terminals.

  According to the graph of FIG. 7, for example, when a parent and a child are accompanied, a change in the difference φ between the traveling azimuth of the mobile terminal possessed by the parent and the traveling azimuth of the mobile terminal possessed by the child is represented. . If the variance of the difference φ is equal to or less than the predetermined threshold Ψ, it is determined that the trajectory is similar.

  Note that the time of the traveling azimuth angle does not necessarily have to be the same for the two mobile terminals. The difference φ at the same time can be calculated by complementing the traveling azimuth angle between the first time and the second time.

The tracking unit 116 is executed in the following case.
(1) When one or both of the local mobile terminal and the counterpart mobile terminal are stopped by the position estimation unit 117 (2) When the curve segment determination unit 113 determines that there is no curve segment (3) When it is determined as dissimilar by the locus similarity determination unit Here, the distance between the first mobile terminal and the second mobile terminal is determined, and when the distance is more than a predetermined threshold (for example, 20 m), It is determined that the person is “not accompanied”. On the other hand, when the distance is not more than the predetermined threshold, it is not determined as “non-accompanying”, but is determined as “accompanying”.

The distance Dt between the mobile terminals A and B at time t is calculated as follows.
Position coordinates of mobile terminal A (x _At , y _At )
Position coordinates of mobile terminal B (x _Bt , y _Bt )
Dt = √ ((x _At −x _Bt ) ² + (y _At −y _Bt ) ² )

  It is also preferable to change the predetermined threshold of the distance for determination in the tracking unit 116 according to the moving speeds of the two mobile terminals. It is also preferable that the predetermined threshold is set to be relatively short if the moving speed is about walking, and the predetermined threshold is set to be relatively long if the moving speed is about the vehicle speed.

  The application processing unit 120 estimates that the first mobile terminal and the second mobile terminal determined to be similar to the locus are in the “accompanying” state, and executes a predetermined application. Further, based on the determination result in the tracking unit 116, it is estimated that “clearly accompanying the person” or “possible non-accompanying person”.

  FIG. 8 is a functional configuration diagram of the mobile terminal in the present invention.

  According to the mobile terminal of FIG. 8, all of the functional components of the accompanying estimation apparatus of FIG. 2 are provided, and the positioning unit 103, the atmospheric pressure sensor 104, or the Bluetooth communication unit 105 is optionally further provided. Moreover, the position estimation part 117 and the early determination part 118 are further provided as an option. Similar to FIG. 2, the position estimation unit 117 and the early determination unit 118 are also realized by executing a program that causes a computer mounted on the mobile terminal to function.

  The position estimation unit 117 moves with the passage of time both of the location information of the local mobile terminal output from the positioning unit 103 and the location information of the counterpart mobile terminal output from the communication interface unit 101. Only in this case, the location information of the local mobile terminal and the location information of the counterpart mobile terminal are output to the fluctuation angle calculation unit 111. This is because the fact that both mobile terminals are moving is a premise for determining the accompanying state. Of course, the position estimation unit 117 is not limited to the case where the accompanying estimation device is a mobile terminal, and may be incorporated in the accompanying estimation device of FIG.

  In addition, according to FIG. 8, the trajectory similarity determination unit 115 outputs the difference in traveling azimuth angle to the position estimation unit 117 when it is determined that the local mobile terminal and the counterpart mobile terminal are trajectory similar.

  On the other hand, the position estimation unit 117 includes the difference of the traveling azimuth as an offset in the position information of the counterpart mobile terminal with respect to the position information of the local mobile terminal. Of course, such an offset is not limited to the case where the accompanying estimation apparatus is a mobile terminal, and may be incorporated in the accompanying estimation apparatus of FIG.

  FIG. 9 is an explanatory diagram of an offset in the position estimation unit.

  The offset includes an azimuth angle difference (rotation error) and a position difference (translation error). In the case of absolute positioning, the position estimation unit obtains a translation offset so that the relative distance becomes zero. In the case of relative positioning, both coordinates are set to (0, 0).

The translation offset (o _x , o _y ) of the mobile terminal A with respect to the mobile terminal B is defined as (x _A0 , y _A0 ), (x _B0 , y _B0 ) where the first coordinates in the curve section of the mobile terminals A and B are , (X _A0 −x _B0 , y _A0 −y _B0 ). Moreover, the rotation offset Ф with respect to the mobile terminal B in the mobile terminal A can be calculated by the average of the azimuth difference φ in the curve section.
Ф ＝ arctan (Σsinφ _i / Σcosφ _i )

  The early determination unit 118 is provided as an option, and determines that it is “accurately accompanying” or “definitely not accompanying”. For example, the relative distance between the two can be estimated by using the electric field strength in the Bluetooth communication unit 105, which is very rough. If it is at least out of service area, it can be “definite accompany”. In addition, the early determination unit 118 can use the atmospheric pressure value (altitude) in the atmospheric pressure sensor 104 to make “definite accompaniment” on the assumption that the floors are different if the atmospheric pressure values between the two parties are significantly different. If the early determination unit 118 does not determine “accurate non-accompanying”, the “accompanying” state is determined by the processing after the position estimation unit 117.

As described above, according to the accompanying determination apparatus, mobile terminal, and program of the present invention, it is possible to accurately estimate the accompanying state in a plurality of mobile terminals even if the measurement error of the mobile terminal is unknown. .

  Various changes, modifications, and omissions of the above-described various embodiments of the present invention can be easily made by those skilled in the art. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

DESCRIPTION OF SYMBOLS 1 Accompanying estimation apparatus 101 Communication interface 102 Position information database 103 Positioning part 104 Barometric pressure sensor 105 Bluetooth communication part 111 Fluctuation angle calculation part 112 Peak time point extraction part 113 Curve section determination part 114 Travel direction angle difference extraction part 115 Trajectory similarity determination part 116 Tracking Unit 117 position estimation unit 118 early determination unit 120 application processing unit 2 GPS satellite

Claims (6)

Storing position information of that mobile terminals put in each time, a bank judging apparatus for estimating the bank status of the plurality of mobile terminals,
For a given azimuth, the traveling azimuth theta _t-1 at previous time, variation calculating a heading angle theta _t at the current time, the magnitude of the difference between the advancing azimuth angle theta _t-1 and the traveling azimuth theta _t Variation angle calculating means for calculating the angle Δθ _t ,
A peak time point extracting means for extracting a peak time point at which the fluctuation angle Δθ _t fluctuates more than a predetermined threshold value from increase to decrease;
A curve section determining means for extracting a linear movement section having a minimum time τ or more between the peak time points and determining a curve section when three or more linear movement sections are continuous;
A traveling azimuth difference extraction means for comparing the curve section of the first mobile terminal and the curve section of the second mobile terminal and extracting the difference of the traveling azimuth angle θ at the same time;
The first mobile terminal and the second mobile terminal have a trajectory similarity determination unit that determines that the trajectory is similar when the variance of the difference in the traveling azimuth angle θ is equal to or less than a threshold value. The accompanying first and second mobile terminals are estimated to be in the “accompanying” state.   2. The accompanying determination apparatus according to claim 1, wherein the curve section determination unit further extracts only a linear movement section within a maximum time T.   When it is not determined that the trajectory is similar, the distance between the first mobile terminal and the second mobile terminal is determined, and when the distance is greater than or equal to a predetermined threshold, it is determined that the vehicle is “non-accompanying”. The accompanying determination apparatus according to claim 1, further comprising a tracking unit. A mobile terminal equipped with the accompanying determination device according to any one of claims 1 to 3,
A positioning unit for positioning the current position information;
A communication interface unit that receives position information of the counterpart mobile terminal from the counterpart mobile terminal or server;
Only when both the location information of the local mobile terminal output from the positioning unit and the location information of the counterpart mobile terminal output from the communication interface unit are moving over time, the local side A mobile terminal further comprising position estimation means for outputting position information of the mobile terminal and position information of the counterpart mobile terminal to the fluctuation angle calculation means. The trajectory similarity determining means outputs the difference of the traveling azimuth angle to the position estimating means when it is determined that the local mobile terminal and the counterpart mobile terminal are trajectory similar,
5. The mobile terminal according to claim 4, wherein the position estimation unit includes the difference in the traveling azimuth as an offset in the position information of the counterpart mobile terminal with respect to the position information of the local mobile terminal. Storing position information of that mobile terminals put in each time, a bank judging program to function a computer mounted to the apparatus for estimating the bank status of the plurality of mobile terminals,
For a given azimuth, the traveling azimuth theta _t-1 at previous time, variation calculating a heading angle theta _t at the current time, the magnitude of the difference between the advancing azimuth angle theta _t-1 and the traveling azimuth theta _t Variation angle calculating means for calculating the angle Δθ _t ,
A peak time point extracting means for extracting a peak time point at which the fluctuation angle Δθ _t fluctuates more than a predetermined threshold value from increase to decrease;
A curve section determining means for extracting a linear movement section having a minimum time τ or more between the peak time points and determining a curve section when three or more linear movement sections are continuous;
A traveling azimuth difference extraction means for comparing the curve section of the first mobile terminal and the curve section of the second mobile terminal and extracting the difference of the traveling azimuth angle θ at the same time;
For the first mobile terminal and the second mobile terminal, when the variance of the difference in the traveling azimuth angle θ is equal to or less than a threshold, the computer functions as a trajectory similarity determination unit that determines trajectory similarity. It is estimated that the determined first mobile terminal and second mobile terminal are in the “accompanying” state.

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