JP2019158608A - Location estimation device, location estimation program, and location estimation method - Google Patents

Abstract

To prevent deterioration of location estimation accuracy even when a movement of a terminal before and after reception of a signal from a transmitter includes retention.SOLUTION: A location estimation device comprises an acquisition unit and a location estimation unit. The acquisition unit is configured to acquire a time and reception signal intensity when a terminal receives a signal, and acquire first location time information acquired in a first post at a first time earlier than the reception time, and second location time information acquired in a second point at a second time later than the reception time. The location estimation unit is configured to calculate an average movement speed between the first point of the terminal and the second point thereof from the first location time information and the second location time information; when the average movement speed is equal to or less than a prescribed value and a distance between the first point and the second point is equal to or more than a prescribed distance, make a correction with respect to at least one of a first time interval between the first time and the reception time and a second time interval between the reception time and the second time; and conduct estimation of a location of the terminal at the reception time and a location of the transmitter at the reception time on the basis of the at least one post-corrected time interval.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a position estimation device, a position estimation program, and a position estimation method.

  2. Description of the Related Art In recent years, customer behavior analysis using location information has been performed for advertisement distribution in commercial facilities and the like and layout layout in stores. In general, for example, a GPS (Global Positioning System) is used to acquire position information. However, there are many cases in which it is difficult for GPS to grasp the position information of an object indoors. On the other hand, for example, a beacon can be used indoors and can be installed at a low cost, so it is often used for acquiring position information.

  In order to utilize a beacon, the beacon identifier and the position information related to the installation position of the beacon must be acquired in advance, and these must be made available. There are cases where it is not obtained. For this reason, it is sometimes required to accurately grasp and create a database of position information (described as beacon position information) related to the beacon installation position.

  A signal transmitted from a beacon does not necessarily include position information of the beacon. For this reason, the terminal which can receive the signal from a beacon cannot necessarily acquire the positional information of the beacon directly from the beacon at the time when the signal is received from the beacon.

  Here, as a method for acquiring the position information of an object including a beacon, for example, a method of detecting the position of the object using signals from a plurality of nodes whose positions are known at the same time is known. . However, when the object is moving, or when signals transmitted from a plurality of nodes are not transmitted at the same time, the accuracy of estimation of the position of the object may be reduced.

  On the other hand, for example, a method is known in which a weight is determined according to an irradiation range of a signal from a node whose position can be grasped to an object, and the position of the object is detected using a weighted average of the signal. However, when the acquisition interval of each signal from a plurality of nodes is large, the estimated position of the target object may be different from the actual position of the target object.

JP 2013-073338 A

Wireless position detection technology, measurement and control, 48 (7), 560-564, 2009

  Nodes used for estimating the position of a transmitter such as a beacon may not necessarily be identified, and even if there is a node whose position is identified, the node can receive signals from the beacon. It may not always be. For this reason, the method of estimating the position of a beacon using the mobile terminal which can receive a signal from a beacon and can acquire position information from a node whose position is specified is considered. In this case, as the beacon position estimation method using the terminal, the position information acquired by the terminal and acquired before and after reception of the signal from the beacon is used to estimate the position of the beacon. A way to do this is conceivable. In this case, for the position estimation, the time when the signal from the beacon received by the terminal, the information on the intensity of the signal, the time when the position information is acquired, and the position information can be used.

  However, the terminal does not always move at a constant speed, and there are cases where the terminal stays. For this reason, there are cases where it is not appropriate to estimate the position of the beacon using the time before and after receiving the beacon and the position information obtained at that time. On the other hand, as the positions related to the position information acquired at the time before and after receiving the beacon are closer to each other, the position related to the position information is considered to be closer to the position of the beacon, and the terminal stays It is not appropriate to exclude cases.

  An object according to one aspect of the present invention is to prevent deterioration in accuracy of position estimation even when movement of a terminal before and after reception of a signal from a transmitter includes retention.

  A position estimation apparatus according to one aspect includes an acquisition unit and a position estimation unit. The acquisition unit acquires the reception time when the terminal receives a signal from the transmitter and the strength of the signal received by the terminal. In addition, the acquisition unit includes the first location time information acquired at the first point by the terminal at the first time before the reception time, and the second point at the second time after the terminal by the reception time. The second position time information acquired in step (1) is acquired. The position estimation unit calculates an average moving speed between the first point and the second point of the terminal from the first position time information and the second position time information. The position estimation unit determines whether the average moving speed is equal to or less than a predetermined value and the distance between the first time and the reception time when the distance between the first point and the second point is equal to or greater than the predetermined distance. Correction is performed on at least one of the first time interval and the second time interval between the reception time and the second time. The position estimating unit estimates the position of the terminal at the reception time based on at least one of the first time interval and the second time interval after correction, and estimates the position of the transmitter based on the estimation. I do.

  Even when the movement of the terminal before and after the reception of the signal from the transmitter includes staying, deterioration in accuracy of position estimation is prevented.

It is a figure which shows an example of a structure of the position estimation system which concerns on 1st Embodiment. It is a figure for demonstrating the function of the functional block of the position estimation apparatus which concerns on 1st Embodiment, and the processing content. It is a figure for demonstrating a response | compatibility with the locus | trajectory of movement of a terminal, and locus | trajectory extraction information. It is a figure which shows an example of the position estimation method using a coordinate and a time interval. It is a figure which shows an example of the stay of a terminal. It is a figure which shows an example of passage of a terminal. It is a flowchart of the process by the position estimation apparatus which concerns on 1st Embodiment. It is a figure which illustrates the reception information and position time information which were acquired by the data acquisition part. It is a figure which illustrates the locus | trajectory extraction information produced | generated by the locus | trajectory extraction part. It is a flowchart of the process by the position estimation part in 1st Embodiment. It is a figure which illustrates the locus information generated based on processing of a position estimating part. It is a figure which shows the comparative example of each precision at the time of performing the position estimation using a prior art, and the position estimation in 1st Embodiment. It is a figure which shows an example of a structure of the position estimation system which concerns on 2nd Embodiment. It is a figure for demonstrating the processing content of each functional block of the position estimation apparatus which concerns on 2nd Embodiment. It is a flowchart of the process by the position estimation apparatus which concerns on 2nd Embodiment. It is a flowchart of the process by the error determination part in 2nd Embodiment. It is a figure for demonstrating an example of the error determination process by the position estimation apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating an example of the error determination process by the position estimation apparatus which concerns on 2nd Embodiment. It is a figure which shows an example of the effect by performing the error determination process in 2nd Embodiment. It is a figure which shows an example of a structure of the position estimation system which concerns on 3rd Embodiment. It is a figure for demonstrating the processing content of each functional block of 2 C of position estimation apparatuses which concern on 3rd Embodiment. It is a flowchart of the process by the position estimation apparatus which concerns on 3rd Embodiment. It is a flowchart of the process by the error position estimation apparatus in 3rd Embodiment. It is a figure which shows the example of the error position estimation process in 3rd Embodiment. It is a figure which shows the example of the error position estimation process in 3rd Embodiment. It is a figure which shows the example of the error position estimation process in 3rd Embodiment. It is a figure which shows the example of the error position estimation process in 3rd Embodiment. It is a figure which shows an example of the effect acquired in position estimation by 2 C of position estimation apparatuses which concern on 3rd Embodiment. It is a figure which shows the position estimation method which concerns on the other Embodiment 1. FIG. It is a figure which shows the functional block of the position estimation apparatus which concerns on other Embodiment 1. It is a figure which shows the functional block of the position estimation apparatus which concerns on the other Embodiment 2. FIG. It is a figure which shows an example of the process by the position estimation apparatus which concerns on other Embodiment 2. FIG. It is a figure which shows an example of the hardware constitutions for implement | achieving each function of each position estimation apparatus which concerns on 1st, 2nd, 3rd embodiment and other Embodiment 1,2,3,4.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a configuration of a position estimation system 1A according to the present embodiment. A position estimation system 1A according to the present embodiment includes a position estimation device 2A, a movement history database 3, a position information master database 4, and the like. The movement history database 3 and the position information master database 4 are each connected to the position estimation device 2A. In addition, the position estimation system 1 includes one or more terminals 6 that are connected to the movement history database 3 through a network 5 so as to be able to communicate wirelessly. The network 5 is a wired or wireless network. The position estimation system 1 </ b> A includes one or more sensors 7 and beacons 8 that can communicate with each terminal 6 wirelessly via the network 5. Such a sensor 7 or beacon 8 is also referred to as a transmitter. The sensor 7 or the beacon 8 may be connected to the movement history database 3 so as to be communicable by wire or wirelessly.

  In the example shown in FIG. 1, the position estimation device 2A, the movement history database 3 and the position information master database 4 are represented separately from each other. However, the position estimation device 2A includes the movement history database 3 or the position information. A master database 4 may be included.

  The position estimation device 2A includes functional blocks such as a data acquisition unit 20, a trajectory extraction unit 21, and a position estimation unit 22 as shown in FIG. These functional blocks will be described later.

  The movement history database 3 is stored in, for example, a storage in cloud computing. In this embodiment, the data recorded in the movement history database 3 is information received by the movement history database 3 from each terminal 6, and this information includes the information from the terminals 7 and the beacons 8. Contains received data. However, the present invention is not limited to this, and the sensor 7 or the beacon 8 may transmit information including data received from the terminal 6 to the movement history database 3.

  The position information master database 4 is stored in a storage device or the like for managing and storing position information. In the position information master database 4, coordinates of positions at which broad sensors such as the sensor 7 and the beacon 8 are arranged, or coordinates of positions estimated to be arranged are recorded.

  The terminal 6 is, for example, a mobile phone, a smartphone, a tablet, a car navigation system, a train driver support system, or the like. Each terminal 6 is given a unique ID (IDentification). The terminal 6 receives signals from the sensor 7 and the beacon 8 via the network 5 and transmits data to the movement history database 3. The terminal 6 transmits a signal to the sensor 7 or the beacon 8 as appropriate. Note that the signal here is a radio wave modulated for wirelessly transferring information.

  In the present embodiment, the sensor 7 is assumed to know the coordinates of the attached position. The sensor 7 transmits a signal corresponding to the information on the coordinates. And the terminal 6 receives the signal from the sensor 7, and acquires the information of the coordinate of the installation position of the sensor 7. FIG. In addition, when the installation position of the sensor 7 is not specified, the sensor 7 may be a target of position estimation described below.

  In the present embodiment, the beacon 8 is a target for estimation of the position where the beacon 8 is attached. However, the beacon 8 may have a specified position. In this case, for example, in order to confirm the attachment position of the beacon, position estimation as described later may be performed. Each beacon 8 is given a unique identifier. The beacon 8 transmits a signal corresponding to its own identifier, and the terminal 6 that has received the signal acquires the identifier of the beacon 8.

  When the terminal 6 acquires the coordinates of the installation position from the sensor 7, the terminal 6 transmits information including the coordinates and information of the time at which the terminal 6 was acquired (also referred to as position time information) to the movement history database 3 together with its own ID. To do. In addition, what combined ID with position time information is also described as position time information below.

  Here, instead of the time when the terminal 6 acquires the coordinates from the sensor 7, the terminal 6 may transmit the following time information to the movement history database 3. For example, the sensor 7 transmits information related to the time when the coordinate information is transmitted to the terminal 6 together with the coordinate information, and the terminal 6 transmits the information related to the time received at this time to the movement history database 3. You may send it. Such time and coordinate information, or information in which the ID of the terminal 6 is combined with this, is also referred to as position time information.

  The terminal 6 can acquire the identifier of the beacon 8 from the beacon 8 within a range where the radio wave reaches. The terminal 6 relates to its own ID, the identifier of the beacon 8, the strength of the radio wave from the beacon 8 when acquiring the identifier of the beacon 8 (also described as signal strength), and the time at which the signal is received from the beacon 8. Information is transmitted to the movement history database 3. Here, the information transmitted from the terminal 6 to the movement history database 3 including the identifier from the beacon 8 is also referred to as reception information.

  Here, the strength of the radio wave from the beacon 8 received by the terminal 6 increases as the beacon 8 and the terminal 6 are closer, and thus becomes an index indicating the proximity of the terminal 6 from the beacon 8. For this reason, the terminal 6 may transmit to the movement history database 3 a numerical value of the proximity from the beacon 8 instead of the signal strength from the beacon 8.

  When receiving a signal continuously from the same beacon 8, the terminal 6 holds information corresponding to one of the signals and deletes information corresponding to other signals. This is to prevent extra data from being accumulated in the terminal 6. It is assumed that what is held by the terminal 6 according to the present embodiment among information corresponding to a plurality of signals received from the same beacon 8 is information corresponding to the signal received first from the beacon 8. However, the present invention is not limited to this, and for example, the terminal 6 corresponds to information corresponding to the last signal or arbitrarily selected signal among information corresponding to a plurality of signals continuously received from the same beacon 8. Information corresponding to other signals may be deleted while leaving information. The terminal 6 includes the information left in this way among the information corresponding to the plurality of signals continuously received from the same beacon 8 in the reception information, and transmits it to the movement history database 3. This is to prevent excess data from being accumulated in the movement history database 3 and to prevent a large amount of data from being transmitted over the network and increasing traffic. When the terminal 6 according to the present embodiment receives a plurality of signals continuously from the same beacon 8, the reception information transmitted to the movement history database 3 is information corresponding to the signal received first from the beacon 8. Is included.

  FIG. 2 is a diagram for explaining functions and processing contents of the functional blocks of the position estimation device 2A according to the present embodiment. The data acquisition unit 20 included in the position estimation device 2 </ b> A reads received information including the identifier of the beacon 8 that is the target of position estimation from the movement history database 3. The beacon 8 whose position is to be estimated is, for example, a beacon 8 whose position is not registered in the position information master database 4 or that it is determined that it is preferable to reconfirm the position even if the position is registered. Beacon 8. The latter is, for example, a beacon 8 in which there is a change in the estimated position every time the position is reconfirmed. Further, the beacon 8 as a position estimation target is not limited to the beacon 8 as described above, and may be an arbitrary beacon 8. For example, the position of an arbitrary beacon 8 may be periodically confirmed.

  The data acquisition unit 20 may receive input from the user such as an identifier of the beacon 8 whose position is to be estimated, and read received information including the identifier from the position information master database 4. Alternatively, the data acquisition unit 20 refers to whether the coordinate information of the beacon 8 is recorded in the position information master database 4 and how much the coordinate of the beacon 8 changes for each update, and based on this, the position is estimated. The target beacon 8 may be selected.

  The data acquisition unit 20 outputs the reception information read from the movement history database 3 to the trajectory extraction unit 21.

  In addition, the data acquisition unit 20 reads position time information including the ID of the terminal 6 in the reception information read from the movement history database 3 from the movement history database 3.

  In the example shown in FIG. 2, the position estimation device 2A estimates the position of each beacon 8 having identifiers p1 and p2. Therefore, the data acquisition unit 20 reads each received information with identifiers p1 and p2 from the movement history database 3. The reception information is shown to the left of the middle part of FIG. Here, although the reception information is represented in a table format, the reception information includes the ID of the terminal 6, the time at which the terminal 6 receives a signal from the beacon 8, the identifier of the beacon 8, and the information from the beacon 8. It is only necessary that the signal strengths are associated with each other.

  The data acquisition unit 20 refers to the ID in the received reception information, and reads position time information including this ID from the movement history database 3. This ID is the ID of the terminal 6 that has received the signal from the beacon 8 whose position is to be estimated. The received information having the identifier p1 exemplified in FIG. 2 includes IDs having ids id1 and id3. For this reason, the data acquisition unit 20 reads each position time information with the IDs “id1” and “id3” from the movement history database 3. Similarly, the data acquisition unit 20 reads the position time information including each of these IDs from the movement history database 3 because the IDs in the received information whose identifier is p2 are id2 and id3.

  The position time information illustrated in FIG. 2 is represented in a table format, but the position time information includes the ID of the terminal 6, the time when the terminal 6 receives a signal from the sensor 7, and the installation position of the sensor 7. It is sufficient that the coordinates are associated with each other. Referring to the position time information in FIG. 2, it can be seen that the terminal 6 whose ID is id1 has acquired the coordinate x11 from the sensor 7 at time t11.

  The trajectory extraction unit 21 collects the reception information and the position time information read by the data acquisition unit 20 for each ID, and sorts them in order of time. On the right side of FIG. 2, data obtained by the trajectory extraction unit 21 collecting reception information and position time information for each ID and sorting them in time order is shown. Referring to the data, for example, it can be seen that the terminal 6 whose ID is id2 receives a signal related to information including the coordinate x21 from the sensor 7 installed at the coordinate x21 at time t21. Then, the terminal 6 receives a signal of strength v22 from the beacon 8 whose identifier is p2 at the subsequent time t22, and further receives a signal from the sensor 7 installed at the coordinate x23 at the subsequent time t23. Recognize. It can be seen that the terminal 6 subsequently receives a signal from the sensor 7 installed at the coordinate x24 at time t24.

  The trajectory extraction unit 21 further summarizes this data for each beacon 8. This process may be performed prior to the process of collecting the reception information and the position time information for each ID. When one terminal 6 is receiving signals from two or more beacons 8, even if location time information including the ID of the terminal 6 is collected for each piece of reception information related to these beacons 8 Good.

  The trajectory extraction unit 21 includes information based on reception information and position time information including each time immediately before and immediately after the time in the reception information in data in which reception information and position time information are collected for each ID and sorted in time order. Extract information based on. For example, in the data shown on the right side of FIG. 2, when the ID is id2, the trajectory extraction unit 21 sets the line at time t22, the line at time t21 immediately before time t22, and the time t23 immediately after time t22. Information corresponding to each row is extracted. Thus, the information extracted by the locus extraction unit 21 is also referred to as locus extraction information.

  The position estimation unit 22 calculates and estimates the coordinates of the installation position of each beacon 8 from the locus extraction information generated by the locus extraction unit 21. Detailed processing by the position estimation unit 22 will be described later.

  FIG. 3 is a diagram for explaining the correspondence between the movement trajectory of the terminal 6 and the trajectory extraction information. The beacon 8 in this embodiment shown in FIG. 3 is fixedly installed. As shown in FIG. 3, the terminal 6 can move along a path indicated by a solid line. As shown in FIG. 3, each terminal 6 receives signals from the sensor 7 and the beacon 8 along with the movement indicated by the broken line. Note that the direction of the broken arrow indicates the moving direction of the terminal. Hereinafter, the locus extraction information and the movement of the terminal 6 will be specifically described in association with each other.

  In the left diagram of FIG. 3, for example, with reference to the terminal 6 with ID 4, the terminal 6 receives a signal from the sensor 7 at or near the point A, and coordinates of the point A that is the installation position of the sensor 7. You can see that Referring to the trajectory extraction information, it can be seen that the terminal 6 of ID4 has acquired the coordinates (10, 10) of the point A from the sensor 7 at the time 0 and the point A. The unit of time is, for example, seconds or minutes. Subsequently, the terminal 6 receives a signal having an intensity of 100 from the beacon 8 when the time is 40 on the moving route. The terminal 6 acquires the coordinates (80, 30) of the point B from the sensor 7 at the time 90 and the point B. Similarly, for each of the other terminals whose IDs are 1, 2, 3, 5, and 6, the travel route, the acquired information, the time when the information is acquired, and the like are known from FIG. In this embodiment, when the terminal 6 receives a signal from the sensor 7 at a certain point, the coordinates of the sensor 7 are the coordinates of the position that is equal to the coordinates of the point or the distance from the point is sufficiently small. Suppose there is.

  As illustrated in FIG. 3, the trajectory extraction information indicates, for each terminal 6, data indicating reception of a signal from the beacon 8 and reception of a signal from the sensor 7 before and after reception of the signal from the beacon 8. It can be seen that data is extracted. For this reason, these data of a certain terminal 6 are described as locus extraction information of the terminal 6.

  FIG. 4 is a diagram illustrating an example of a position estimation method using coordinates and time intervals. Here, the position estimation method will be described with reference to the movement route, reception status, and locus extraction information of the terminal 6 of ID3 shown in FIG. The terminal 6 acquires information of coordinates (80, 70) from a certain sensor 7 at a point C at time 0. Thereafter, the terminal 6 receives a signal with an intensity of 90 from the beacon 8 with the identifier p1 at time 40. This signal is a signal related to the information of the identifier p1 of the beacon 8. Thereafter, the terminal 6 acquires information on the coordinates (10, 0) from another certain sensor 7 at a point D at time 70.

  Here, referring to the trajectory extraction information of the terminal 6 with ID 3 as shown in FIG. 4, it is not always possible to obtain information on the movement route other than the information regarding each position of the terminal 6 at time 0 and time 70. Absent. As described above, the position estimation device 2 </ b> A is not always able to acquire information on the movement route of each terminal 6. In order to estimate the position of the beacon 8, the position estimation device 2 </ b> A according to the present embodiment estimates the position of the terminal 6 when the terminal 6 receives a radio wave from the beacon 8. However, in order to estimate the position where the terminal 6 has received the radio wave from the beacon 8, the position estimation device 2 </ b> A must increase the number of sensors 7 in order to obtain information on the movement path of the terminal 6. May increase the traffic. In order to avoid such a situation, the position estimation device 2A according to the present embodiment uses the trajectory extraction information as shown in FIGS. Is used to estimate the position where the signal is received. Processing from here is performed by the position estimation unit 22 described above.

  In the case illustrated in FIG. 4, the position estimation unit 22 refers to the trajectory extraction information and approximates the movement route of the terminal 6 with ID3 by a line segment connecting the point C and the point D. Then, the position estimation unit 22 determines that the time 40 when the terminal 6 receives the signal from the beacon 8 with the identifier p1 is between the time 0 when the terminal 6 exists at the point C and the time 70 when the terminal 6 exists at the point D. To calculate where it is located. From the locus extraction information, it can be seen that the time interval until the terminal 6 moves from the point C and receives the beacon 8 signal is 40, and the terminal 6 arrives at the point D after receiving the beacon 8 signal. It can be seen that the time interval until is 30. As a position of the beacon 8 or a position at which the terminal 6 is considered to have received the signal from the beacon 8, the line segment connecting the point C and the point D is generally calculated using a linear interpolation, that is, a time interval ratio, It is possible to divide 4 to 3 internally. However, as is apparent from the illustration in FIG. 4, such an internal dividing point is not necessarily equal to the actual installation position of the beacon 8 or the position where the terminal 6 receives a signal from the beacon 8.

  Hereinafter, each point where the terminal 6 acquires coordinate information from the sensor 7 before and after receiving a signal from the beacon 8 is also referred to as a first point and a second point. Hereinafter, the time at which the terminal 6 acquires the information related to the coordinates from the sensor 7 at the first point is also referred to as the first time. Similarly, the time when the terminal 6 acquires information related to coordinates from the sensor 7 at the second point is also referred to as a second time. Similarly, the time when the terminal 6 receives a signal from the beacon 8 is also referred to as a reception time. A time interval between the first time and the reception time is also referred to as a first time interval. Similarly, the time interval between the reception time and the second time is also referred to as a second time interval. Further, in the following, the internal dividing point means a point that internally divides a line segment connecting the first point and the second point by the ratio of the first time interval and the second time interval. .

  Here, in the present embodiment, in order to accurately estimate the position of the terminal 6 at the reception time, the stay described below is considered. FIG. 5 is a diagram illustrating an example of retention of the terminal 6. Here, the stay of the terminal 6 with ID5 will be described. The left diagram in FIG. 5 shows the actual movement route of the terminal 6 with ID5. The solid line and the broken line here indicate the path and the movement route of the terminal 6, respectively, as in FIGS. Each figure such as the beacon 8 and the position at which the terminal 6 has received information from the sensor 7 is the same as in FIGS.

  When the terminal 6 does not move for a while from the range in which the radio wave from the beacon 8 can be received, the terminal 6 can receive a plurality of signals from the beacon 8. In order to facilitate understanding, it is assumed that the terminal 6 transmits received information corresponding to each of the plurality of signals to the movement history database 3. Here, a case is considered where the terminal 6 with ID 5 continuously receives a plurality of signals from the same beacon 8 and transmits a plurality of reception information corresponding to these to the movement history database 3. At this time, the trajectory extraction unit 21 arranges the reception information from the terminal 6 and the position time information in order of time, and generates data as shown in the middle part of FIG. However, the reception information transmitted to the movement history database 3 by the terminal 6 in the present embodiment only corresponds to the signal received first from the beacon 8, and the above-described assumption is for explaining the stay. .

  From the left figure in FIG. 5 and the data in the middle part, the terminal 6 of ID5 moves along the route indicated by the broken line in FIG. You can see that Subsequently, after receiving the signal from the beacon 8 at time 40, the terminal 6 moves at a speed lower than the speed up to time 40 or stays at or near the same point until time 80. I understand. Then, it can be seen that the terminal 6 moves at a speed higher than the speed from the time 40 to the time 80 from the time 80 to the time 90 and acquires coordinate information from the sensor 7 at the time 90. The trajectory extraction information extracted for such movement of the terminal 6 is shown in the lower right of FIG.

  The route derived as the movement route of the terminal 6 from this locus extraction information is a route along the line segment connecting the first point (E) and the second point (F) shown in the upper right of FIG. . The point that can be recognized as the installation position of the beacon 8 is a point obtained by internally dividing the route represented by the line segment according to the ratio (4: 5) of the first time interval 40 and the second time interval 50. It becomes the point G which is. However, the actual position of the beacon 8 is close to the point F. If the distance between the point E and the point F is not small, or if the time spent for the terminal 6 to move from the point E to the point F is not small, the point G is determined from the actual beacon 8 installation position. It can be a remote point. As described above, the estimation accuracy of the position of the beacon 8 may be deteriorated due to the influence of the moving speed of the terminal 6.

  In this embodiment, the case where the average moving speed of the terminal 6 is equal to or less than a predetermined value is defined as staying. The predetermined value is a value set in advance by the user. This predetermined value is predetermined for each type of terminal 6. For example, the terminal 6 may be a car navigation system, a mobile phone, or the like, and the predetermined value is determined in advance in each of these cases.

  The position estimation unit 22 in this embodiment refers to the locus extraction information for the terminal 6 used for position estimation of the beacon 8 and calculates the average moving speed between the first point and the second point of the terminal 6. To do. Next, the position estimation unit 22 determines whether or not the terminal 6 is staying from the average moving speed. The position estimation unit 22 determines that the terminal 6 is staying, and if the distance between the first point and the second point is a predetermined distance or more, the second time Correct the interval. This correction is performed, for example, by converting the terminal 6 into a time interval or the like that is estimated to have actually taken the movement when there is no stagnation. For this conversion, the movement history database 3, the position information master database 4, or another database has an unspecified amount of time in the range assumed as the installation position of the beacon 8 or in the vicinity of the second point. Data such as whether the terminal 6 continues to be located is held. This data was accumulated through the terminal 6 that acquired information from other beacons 8 and sensors 7 where the installation location was specified in the vicinity of the second point and in the range where the beacon 8 is estimated to be installed. It may be a thing. The data may be accumulated via a number of terminals 6 that have received signals from beacons 8 whose installation positions are not specified but are expected to be within the range. The person who makes settings for the position estimation unit 22 or the position estimation apparatus 2A uses this data to examine in advance how the time interval that should have taken the original movement changes due to staying. Determine whether to correct. For example, when there is statistical data that an unspecified number of terminals 6 continue to be located for an average of 100 minutes in a certain range of distance of about 10 minutes, the position estimation unit 22 determines the second of the terminals 6 that are staying. The time interval of 1 is multiplied by 1/10. Alternatively, if there is statistical data such that an unspecified number of terminals 6 remain in the range for an average of one hour even though the distance from end to end of a certain range is not large, the position estimation unit 22 Subtract 1 hour from the time interval.

  Here, the reason for correcting the second time interval is as follows. First, the place where the beacon 8 is provided is often a place where the terminal 6 is considered to stay, such as a restaurant. Further, when a plurality of signals are continuously received from the same beacon 8, the terminal 6 transmits the reception information related to the first signal to the movement history database 3 and does not transmit the reception information related to other signals. For this reason, the time interval from the last reception of a signal from the same beacon 8 to the next acquisition of coordinate information from the sensor 7 is unknown. This time interval is considered to be approximately equal to the second time interval when there is no residence. For this reason, the position estimation part 22 correct | amends a 2nd time interval using statistics, such as the residence time of the said point.

  On the contrary, when the terminal 6 transmits the reception information related to the last signal among the plurality of signals continuously received from the same beacon 8 to the movement history database 3, the position estimation unit 22 Correct the time interval. In addition to these, the position estimation unit 22 may correct both the first time interval and the second time interval. Further, when the received information relates to an arbitrary one of the plurality of signals received from the beacon 8, correction corresponding to this may be performed.

  In the present embodiment, even if there is a stay, if the distance between the first point and the second point is small, for example, if the distance is less than a predetermined distance, the second time interval is corrected. I will not. This is because the range estimated as the installation position of the beacon 8 is not so wide in this case. This is because the calculation amount of the position estimation unit 22 is not increased by not performing the correction. The predetermined distance, which is a boundary between necessity of correction to the second time interval, is appropriately set by the user. For example, what is set as the predetermined distance is, for example, twice an allowable error when the distance between the actual installation position of the beacon 8 and the estimated position of the beacon 8 is an error, or It is the error plus a constant value.

  The position estimation device 2A according to the present embodiment can be obtained by linear interpolation using a ratio between the corrected second time interval and the first time interval when the second time interval is corrected. The coordinates of the internal dividing point are estimated as the position of the terminal 6 at the reception time. On the other hand, when the correction is not performed on the second time interval, the position estimation device 2A determines the internal division obtained by linear interpolation using the ratio between the original first time interval and the second time interval. The coordinates of the point are estimated as the position of the terminal 6 at the reception time. Note that the coordinates of the internal dividing points obtained by such linear interpolation are also referred to as interpolation coordinates or linear interpolation coordinates. Since the linear interpolation coordinates are obtained for each terminal 6, the linear interpolation coordinates of the terminal 6 and the interpolation coordinates of the terminal 6 are also described.

  While the terminal 6 may stay, the accuracy of estimating the position of the beacon 8 may be deteriorated because the average moving speed of the terminal 6 is high. Such a case is described as passing. FIG. 6 is a diagram illustrating an example of passage of the terminal 6. The left diagram in FIG. 6 shows the actual movement route of the terminal 6 with ID3. The solid line and the broken line here indicate the path and the movement route of the terminal 6, respectively, as in FIGS. In addition, the beacon 8 and each figure such as the position where the terminal 6 has received information from the sensor 7 are the same as those in FIGS. The trajectory extraction information of the terminal 6 with ID3 is shown in the middle of FIG. From the left diagram in FIG. 6 and the locus extraction information, it can be seen that the terminal 6 of ID3 has acquired coordinate information from the sensor 7 at the point H at time 0. Then, it can be seen that the terminal 6 moves along the moving route indicated by the broken line on the left in FIG. 6 and receives a signal of strength 90 from the beacon 8 at time 40. Next, it can be seen that the terminal 6 has acquired coordinate information from the sensor 7 at time 70. Here, when the moving speed of the terminal 6 is high, it is considered that at least one of the distance traveled from time 5 to time 40 and the distance traveled from time 40 to time 70 becomes larger. Here, both of these distances are assumed to be large.

  The route derived as the movement route of the terminal 6 from the locus extraction information is a route represented by a broken line shown in the right diagram of FIG. In this case, the distance between the route represented by the line segment connecting the point H and the point I and the actual installation position of the beacon 8 can be large. In this case, the point estimated as the installation position of the beacon 8 is a point J on the route connecting the point H and the point I, which can be a position away from the actual installation position of the beacon 8. Thus, when the moving speed of the terminal 6 is high, there is a high possibility that the accuracy of estimating the position of the beacon 8 by linear interpolation will drop.

  In order to more accurately estimate the installation position of the beacon 8, the position estimation device 2 </ b> A assigns the weights described below to the coordinates of each internal dividing point of the one or more terminals 6 that have received the signal from the beacon 8. To do. Then, the position estimation device 2A estimates the position of the beacon 8 by calculating a weighted average of the coordinates of these internal dividing points.

  First, the signal strength of the beacon 8 corresponds to the proximity from the beacon 8. Therefore, the position where the terminal 6 receives the signal from the beacon 8 is closer to the installation position of the beacon 8 as the strength is higher. For this reason, the weight in this embodiment includes the strength of the signal from the beacon 8 as a parameter.

  Also, the smaller the distance between the first point and the second point, the narrower the range to be estimated as the installation position of the beacon 8, so the weight in this embodiment includes the reciprocal of the distance as a parameter. .

  Further, when the movement speeds of the plurality of terminals 6 are the same, the movement distance becomes smaller as the terminal 6 has a smaller time interval between the first time and the second time. Can be taken into account as parameters. However, in the present embodiment, a shorter time interval (also referred to as a short time interval) out of the first time interval and the second time interval (if corrected, the second time interval after correction). The reciprocal is included in the weight as a parameter. The reason is as follows. Of the first and second time intervals, for example, when the second time interval is small, the internal dividing point is closer to the second point. Conversely, when the first time interval is smaller than the second time interval, the internal dividing point is closer to the first point. Assuming that the short time interval of each of the one or more terminals 6 having the same average moving speed is the second time interval, the inner dividing point estimated as the position at the reception time of each terminal 6 is smaller as the short time interval is smaller. Close to each second point. The coordinates of the second point are also specified. On the other hand, coordinates other than the first and second points are not specified in the movement route of the terminal 6. For this reason, among the linear interpolation coordinates of one or more terminals 6, the range assumed as the installation position of the beacon 8 is narrowed by giving a larger weight to the interpolation coordinates having a shorter short-time interval. It is thought that it will be found. For this reason, the reciprocal of the short time interval is included in the weight as a parameter. However, it is not limited to this.

From these things, in this embodiment, the weight added to a linear interpolation coordinate is defined as follows.
Weight = (x × 1 / y × 1 / z)
Here, x, y, and z represent the intensity of the signal from the beacon 8, the distance between the first point and the second point, and the short time interval, respectively.

  Note that the position estimation device 2A according to the present embodiment does not perform correction in the case of passage. The reason is as follows. Since the average moving speed of the terminal 6 is high, the movement distance becomes large, which causes deterioration in accuracy of position estimation. In the weights described above, the reciprocal of the distance between the first point and the second point is used as a parameter, and the magnitude of the movement distance that causes the deterioration of accuracy has already been taken into consideration. For this reason, the position estimation device 2A according to the present embodiment does not perform the correction as in the case of the stay in the case of passage. However, the present invention is not limited to this. For example, correction may be performed on at least one of the first time interval and the second time interval.

  Hereinafter, the operation of the position estimation device 2A according to the present embodiment will be described. FIG. 7 is a flowchart of processing by the position estimation device 2A according to the present embodiment. The data acquisition unit 20 of the position estimation device 2A acquires, from the movement history database 3, the reception information including the identifier of the beacon 8 that is the position estimation target and the position time information including the ID included in the reception information ( Step S100).

  FIG. 8 is a diagram exemplifying reception information and position time information acquired by the data acquisition unit 20. In step S <b> 100, the data acquisition unit 20 acquires reception information and position time information as exemplified in FIG. 8 from the movement history database 3. The reception information and position time information shown in FIG. 8 correspond to those obtained by substituting specific numerical values for the reception information and position time information shown in FIG.

  From the reception information shown in FIG. 8, it is understood that the position estimation device 2A estimates the installation positions of the beacons 8 with the identifiers p1 and p2 here. Further, from the reception information shown in FIG. 8, for example, it can be seen that the terminal 6 with ID 1 is receiving a signal with intensity 70 from the beacon 8 with identifier p 1 at time 0.

  Further, from the position time information shown in FIG. 8, it can be seen that, for example, the terminal 6 with ID 1 has acquired information (10, 80) that is the coordinates of the sensor from the sensor 7 at time 0.

  Refer to FIG. 7 again. The trajectory extraction unit 21 generates trajectory extraction information using the reception information and position time information acquired by the data acquisition unit 20 (step S101).

  FIG. 9 is a diagram illustrating the trajectory extraction information generated by the trajectory extraction unit 21. The trajectory extraction information shown in FIG. 9 is generated by the trajectory extraction unit 21 from the reception information and the position time information shown in FIG. Here, the information in which the reception information and the position time information are collected is divided for each ID of the terminal 6 and rearranged so that the times are in ascending order. Thereby, the locus | trajectory extraction information for every terminal 6 is produced | generated. In the locus extraction information for each terminal 6, data from position time information immediately before and immediately after receiving a signal from the beacon 8 is used. Here, for example, referring to the locus extraction information of the terminal 6 with ID1, the terminal 6 is the coordinates of the installation position of the sensor 7 from the sensor 7 at time 0 (10, It can be seen that the information 80) is acquired. Further, it can be seen that the terminal 6 has received a signal having an intensity of 70 from the beacon 8 with the identifier p1 at time 7. Furthermore, it can be seen that the terminal 6 has acquired the information (0, 60) that is the coordinates of the sensor 7 from the sensor 7 at time 60. Next, the processing by the position estimation unit 22 in step S102 will be described with reference to FIGS.

  FIG. 10 is a flowchart of processing by the position estimation unit 22 in the present embodiment. FIG. 11 is a diagram illustrating trajectory information generated based on the processing of the position estimation unit 22. The position estimation unit 22 calculates the first time interval, the second time interval, and the distance between the first point and the second point for each terminal 6 based on the trajectory extraction information. Further, the position estimation unit 22 calculates a time interval between the first point and the second point, and thereby divides the distance between the first point and the second point, and calculates the average of the terminal 6 Calculate the moving speed. If the average moving speed of the terminal 6 is greater than a predetermined value, the position estimation unit 22 determines that the terminal 6 is not staying. On the other hand, when the average moving speed of the terminal 6 is equal to or less than the predetermined value, the position estimation unit 22 determines that the terminal 6 is staying. The position estimation unit 22 corrects the second time interval when the distance is a stay and the distance between the first point and the second point is equal to or greater than a predetermined distance (step S200). In other cases, the correction is not performed (step S200).

  In the present embodiment, the position estimation unit 22 calculates the average moving speed of the terminal 6 between the two points regardless of the distance between the first point and the second point. However, the present invention is not limited to this, and the position estimation unit 22 may not calculate the average moving speed between the two points when the distance is smaller than the predetermined distance.

  With reference to FIG. 11, the process of step S200 performed by the position estimation part 22 is demonstrated concretely. The unit of time in FIG. 11 is second. 11 are coordinates on two coordinate axes that are parallel to the ground and orthogonal to each other, such as latitude and longitude, and the unit is meters. Moreover, the unit of the distance in FIG. 11 is a meter. Further, the position estimation unit 22 according to the present embodiment generates trajectory information that is information obtained by extending the trajectory extraction information and includes a value calculated using the trajectory extraction information. However, the position estimation unit 22 may perform the process of step S200, step S201, or step S203 using the trajectory extraction information without generating the trajectory information.

  Here, it is assumed that both the trajectory extraction information and the trajectory information are represented in tabular form. However, the trajectory extraction information or the trajectory information may not be in a tabular format as long as the data in the items in each column of the trajectory extraction information or the trajectory information is stored in association with each ID. Further, the trajectory information does not have to include all the items in the column illustrated in FIG. 11, and may include a part of these items. Alternatively, the trajectory information may have items other than the items in the column shown in FIG. It is assumed that the trajectory information and the trajectory extraction information in the present embodiment are temporarily stored in the position estimation device 2A. The stored trajectory information and trajectory extraction information need not be stored as data that can be recognized by the user, but may be stored so that the position estimation device 2A can perform processing using the data. In addition, the stored information may be updated in accordance with the processing by the position estimation device 2A. For example, when the position estimation device 2A no longer uses information that has been used in the trajectory information after a certain process, the information may be deleted and new information may be added to the trajectory information.

The case of ID1 will be described with reference to FIG. In the locus extraction information, the first time of the terminal 6 with ID 1 is 0, the reception time is 7, and the second time is 60. Here, the position estimation unit 2A calculates the first time interval as 7 and the second time interval as 53. Here, these are recorded in the time interval column of the trajectory information. In the locus extraction information, the coordinates of the first point of the terminal 6 with ID1 are (10, 80), and the coordinates of the second point are (0, 60). From here, the position estimation unit 2A calculates the distance between the first point and the second point, and 22.36 (22.36≈ {(0-10) ² + (60-80) ² } ^{1 / 2} ) is obtained. Here, the value is recorded in the distance column of the trajectory information. Next, the position estimation unit 22 divides the distance between the first point and the second point by the sum of the first time interval and the second time interval, etc., and the average movement of the terminal 6 of ID1 Calculate the speed. Here, the average moving speed is 0.37 (22.36 / 60≈0.37). Here, the average moving speed is recorded in the column of the average moving speed of the trajectory information.

  Here, the determination condition as to whether or not the terminal 6 is staying is determined as to whether or not the average moving speed is 1 or less. That is, when the average moving speed is 1 or less, the staying occurs. Here, since the average moving speed of the terminal 6 with ID1 is 0.37, the position estimation unit 22 determines that the terminal 6 is staying.

  Further, the position estimation unit 22 corrects the second time interval of the terminal 6 because the distance 22.36 between the first point and the second point of the terminal 6 of ID1 is smaller than the predetermined distance. Will not be performed. Here, the predetermined distance related to the determination condition for the distance between the first point and the second point for correcting the second time interval is 25.

  Similarly, the position estimation unit 22 calculates the distance between the first point and the second point for each ID. Moreover, the position estimation part 22 calculates an average moving speed for every ID. Here, referring to the trajectory information for the terminal 6 of ID2, in FIG. 11, the average moving speed is 0.37 which is equal to or less than a predetermined value, so that it can be understood that the terminal 6 of ID2 has stayed. Similarly, the distance between the first point and the second point in the terminal 6 of ID2 is 67.08 which is equal to or greater than a predetermined distance. From these, the position estimation part 22 correct | amends the 2nd time interval of the terminal 6 of ID2. In this correction, the second time interval is multiplied by 1/10, and the result obtained is used as a new second time interval. As a result, the second time interval of 150 of the terminal 6 with ID 2 before correction becomes 15. In the example shown in FIG. 11, the first time interval and the second time interval obtained after the correction processing are shown in the correction time interval column.

  Refer to FIG. 10 again. The position estimation unit 22 calculates an internal dividing point on a line segment connecting the first point and the second point by using a ratio between the first time interval and the second time interval by linear interpolation. (Step S201). The second time interval used here is the corrected time when the above correction is made. Referring to FIG. 11, the linear interpolation coordinates in the case of ID1 that has not been corrected in the second time interval are (8.8, 77.7), and the linear interpolation coordinates in the case of ID2 that has been corrected are ( 30, 40).

  Referring to FIG. 10, the position estimation unit 22 calculates the weight in the case of each ID following step S201 (step S202). In calculating the weight, as described above, the strength of the signal received by the terminal 6 from the beacon 8, the distance between the first point and the second point, and the short time interval are used.

  The process of step S202 will be specifically described with reference to FIG. In the example shown in FIG. 11, the short time interval and the distance between the first point and the second point used for calculating the weight are the acquisition interval / time column and the acquisition interval for each ID, respectively. / Recorded in the distance column. The “acquisition interval / time” indicates a time in the acquisition interval. Similarly, the “acquisition interval / distance” indicates a distance in the acquisition interval. In the case of ID1, since the first time interval is 7 and the second time interval is 53, the short time interval is 7. In FIG. 11, since the distance between the first point and the second point in the case of ID1 is 22.36, 22.4 obtained by rounding off the second decimal place of the value is the acquisition interval / distance. Is shown in the column.

  Similarly, in the case of ID2 in the trajectory information of FIG. 11, the second interval 15 after correction, which is a short time interval, is shown in the acquisition interval / time column, and 67 in the acquisition interval / distance column. .1 is shown.

  The calculation of the weight by the position estimation unit 22 will be described with reference to FIG. For each ID, the position estimation unit 22 substitutes the values of the intensity, the acquisition interval / distance, and the acquisition interval / time for each of x, y, and z in the formula for calculating the weight described above, and sets the weight. calculate. For example, in the case of ID1, the weight is 0.45 (0.45≈70 × 1 / 22.4 × 1/10). The same applies to other IDs.

  Referring back to FIG. 10, the position estimation unit 22 uses the linear interpolation coordinates and weights in each ID to determine the coordinates of the position estimated as the installation position of the beacon 8 (beacon 8 estimation) for each identifier of the beacon 8. (Also described as coordinates or estimated coordinates) is calculated (step S203). The position estimated as the installation position of the beacon 8 is also referred to as an estimated position. Similarly, the position of the terminal 6 in the linear interpolation coordinates is also referred to as the estimated position of the terminal. The position estimation unit 22 stores the estimated coordinates of the beacon 8 obtained in step S203 in the position information master database 4.

  Referring to FIG. 11, the position estimation unit 22 calculates the weighted average using the interpolated coordinates and the weights of IDs 1, 2, and 3 in calculating the estimated coordinates of the beacon 8 with the identifier p1. The estimated coordinates of the beacon 8 are obtained. In FIG. 11, the estimated coordinates are indicated as (9.4, 63). The same applies to the calculation of the estimated coordinates of the beacon 8 with the identifier p2.

  Note that the position estimation device 2 </ b> A may use the coordinates of the beacon 8 output to the position information master database 4 to estimate the position of another beacon 8 whose position is not specified. For example, when estimating the position of a certain beacon 8, the position estimation device 2 </ b> A includes a beacon 8 that includes the estimated position within a certain range from the installation position of the sensor 7 indicated in the position time information used at that time. The estimated coordinates may be used. In this case, the terminal 6 that has received the signal from the beacon 8 whose position is to be estimated, along with the signal from the sensor 7 used for the estimation, the beacon 8 estimated to be located in the vicinity of the sensor 7. There is a high possibility of receiving a signal from. For this reason, the position estimation device 2A uses the reception information from the beacon 8 from which such estimated coordinates are obtained, together with the estimated coordinates of the beacon 8, as position time information, and the position of other beacons 8 May be estimated. In this case, the data acquisition unit 20 acquires the estimated position of the beacon 8 from the position information master database 4. In this case, the data acquisition unit 20 or the trajectory extraction unit 21 generates position time information or trajectory extraction information from the estimated coordinates of the beacon 8 from the position information master database 4 and the reception information related to the beacon 8. In addition, in order to determine whether or not the estimated coordinates of the beacon 8 recorded in the position information master database 4 are reliable, as a result of position estimation of the beacon 8 more than a certain number of times, there is no change in the coordinates, etc. May be recorded in the database.

  FIG. 12 is a diagram illustrating a comparative example of each accuracy when position estimation is performed using the conventional technique and when position estimation is performed in the present embodiment. FIG. 12 shows the result of estimating the coordinates of the installation positions of the beacons 8 with the identifiers p1 and p2 using the trajectory extraction information shown in FIG. In FIG. 12, the case where the conventional technique that does not correct the second time interval is used is shown on the left, and the case where the position estimation method according to the present embodiment that corrects the second time interval is used is shown on the right. Here, it is assumed that the conventional technique includes calculation of the interpolation coordinates of the terminal 6 by the linear interpolation and calculation of the estimated coordinates of the beacon 8 by the weighted average of the interpolation coordinates. However, this assumption is intended to show the effect when the second time interval is corrected, and these are not necessarily included in the actual prior art.

  The estimated positions of the terminals 6 used for estimating the position of the beacon 8 are shown on the left and right in the upper part of FIG. Note that the estimated position of the terminal 6 in the case of using the conventional technique corresponds to the internal dividing point obtained without correcting the time interval. In FIG. 12, as in the case of FIG. 3 and the like, the first point and the second point of each terminal 6 are represented by small circles, and the movement route related to the estimation of each terminal 6 is represented by a broken line. IDn (n is a natural number) given to each of these broken lines indicates the ID of the terminal 6 estimated to have moved along the movement route indicated by the broken line. In addition, a mark indicating a signal (radio wave) from the beacon 8 and having an outline outlined by a broken line is written on the movement route. The point where the mark is located is an estimated position of the terminal 6. .

  In the left and right diagrams in the lower part of FIG. 12, the actual position and the estimated position of each beacon 8 are indicated by marks representing the beacon 8 in a solid line and a broken line, respectively. In addition, the solid line and the broken line ellipse described so as to surround the mark indicating the estimated position of the beacon 8 in the left and right diagrams in the lower part of FIG. 12 indicate how far the installation position of the beacon 8 is from the estimated position of the beacon 8. It is described in order to show. These ellipses indicate a range that can be further estimated as the installation position of the beacon 8 based on the estimated position of the beacon 8. In the lower part of FIG. 12, numerals are shown together with marks that represent a signal from the beacon 8 and whose outline is outlined by a wavy line, which indicates a weight.

  In FIG. 12, attention is paid to the beacon 8 with the identifier p2 and the terminals 6 with IDs 4, 5, and 6 used for position estimation of the beacon 8. Referring to the upper left part of FIG. 12, that is, the figure showing the estimated position of each terminal 6 obtained by using the prior art, the second time interval is not corrected. As shown in FIG. 11, the terminals 6 having IDs 4, 5, and 6 all have a stay. However, such a stay is not reflected in the estimated position of each terminal 6 in the case of the prior art shown in the upper left part of FIG. For this reason, there is a possibility that the estimated position of the terminal 6 obtained by using the conventional technique is greatly different from the position of the terminal 6 at the actual reception time. Thus, in the case of the prior art, an error may occur from the stage of obtaining the estimated position of the terminal 6 before calculating the estimated coordinates of the beacon 8. And the range used as the estimation object of the installation position of the beacon 8 is not narrowed by this. The estimated coordinates of the beacon 8 calculated from the coordinates of the estimated position of the terminal 6 obtained without taking into account the stay are likely to be different from the coordinates of the actual installed position of the beacon 8, and the error is also high. It cannot be ignored. In the example shown in FIG. 12, the error (the distance between the installation position of the beacon 8 and the estimated position) when this conventional technique is used is 13.7 m.

  On the other hand, when the position estimation method according to the present embodiment is used, the fact that the terminals 6 with IDs 4, 5, and 6 have stayed is reflected in each of these interpolation coordinates. Thereby, there is a high possibility that the estimated position at the reception time of the terminal 6 is closer to the actual position. In addition, as a result, the range in which the beacon 8 is expected to be present, as indicated by the dashed ellipse in each of the upper left stage and the upper right stage in FIG. 12, is narrower in the case of using the correction in the present embodiment than in the prior art. Specific to the range. And it is thought that the error in estimation of the installation position of beacon 8 becomes small by performing a weighted average to the interpolation coordinates calculated using this correction. As shown in the lower right of FIG. 12, when the position estimation method according to the present embodiment is used, the estimated position of the beacon 8 is closer to the actual installation position of the beacon 8 than in the conventional case. The error in this case was 6.1 m, which is smaller than that in the case of using the prior art.

  According to this embodiment, even if the movement of the terminal 6 before and after reception of the signal from the beacon 8 includes staying, it is possible to prevent deterioration in accuracy of position estimation.

(Second Embodiment)
In 1st Embodiment, the identifier given to the beacon 8 used as the object of position estimation demonstrated the case where the identifier was uniquely determined for every beacon 8. FIG. However, there may be other beacons 8 (also referred to as spoofed beacons 8F) that illegally have the same identifier as a certain beacon 8. When the impersonation beacon 8F having a certain identifier exists in this way, the following problem may occur in the estimation of the installation position of the beacon 8 having the identifier (also referred to as a valid beacon 8T). In the estimation, the position estimation device 2A can acquire each reception information from the terminal 6 that has received the signal from the legitimate beacon 8T and the terminal 6 that has received the signal from the spoofing beacon 8F. Then, the position estimation device 2 </ b> A can acquire position time information including the IDs of these terminals 6. Thereby, the position estimation device 2A may generate the trajectory extraction information based on the reception information regarding the spoofing beacon 8F as the legitimate beacon 8T. Then, the position estimation device 2A assumes that the terminal 6 that has received a signal from each of these beacons 8 has received a signal from the same beacon 8, and performs weighted averaging with the interpolation coordinates of each terminal 6 combined. there is a possibility. As a result of such weighted average, there is a possibility that the estimated position of the legitimate beacon 8T is shifted from the actual installation position to the installation position of the impersonation beacon 8F.

  In the estimation of the installation position of the beacon 8 having a certain identifier, the position estimation device 2B according to the present embodiment has an error in the position of the estimated beacon 8 when there is another beacon 8 having the same identifier. Can be determined.

  FIG. 13 is a diagram illustrating an example of a configuration of the position estimation system 1B according to the present embodiment. Since elements other than the position estimation device 1B included in the position estimation system 1B in FIG. 13 are the same as those in the first embodiment, description thereof will be omitted. However, the beacon 8 in FIG. 13 is a valid beacon 8T or a spoofed beacon 8F. The position information master database 4 according to the present embodiment stores information on whether or not the estimated position of the beacon 8 is incorrect in addition to the information stored in the case of the above embodiment. The connection relationship between devices included in the system is the same as the connection relationship in the above embodiment regardless of the reference numerals.

The position estimation device 2B includes an error determination unit 23 in addition to the functional blocks described above. The error determination unit 23 is connected to the position estimation unit 22 and acquires the estimated coordinates of the beacon 8 calculated by the position estimation unit 22, the interpolation coordinates of the terminal 6, and the weight. The error determination unit 23 calculates a distance (also referred to as a difference distance) between the estimated position of the beacon 8 and the estimated position of the terminal 6, and calculates an error score using the distance and the weight. Here, the error score is defined as follows in the present embodiment.
Error score = weight x difference distance

  The error score will be described. Since the error score is calculated for each terminal 6, the error score calculated using the interpolation coordinates of a certain terminal 6 is also referred to as the error score of the terminal 6. When the weight given to the interpolation coordinates of the terminal 6 having a certain ID used for estimating the installation position of the beacon 8 having a certain identifier is large, the estimated position of the terminal 6 is normally It is considered close to the installation position. However, when the difference distance is large despite the large weight, it is considered that the terminal 6 has received a signal from the spoofed beacon 8F having the same identifier as the beacon 8. For this reason, the error determination unit 23 has a function of determining that the estimated position of the beacon 8 is incorrect when the error score of a certain terminal 6 is larger than the threshold in estimating the installation position of the beacon 8 with a certain identifier. .

  In addition, this threshold value shall be a value suitably set by the user based on, for example, an average value of the distance between two beacons 8 out of a plurality of arbitrary beacons 8 whose installation positions are specified.

  In addition, the error score is not limited to the above definition, and may be, for example, the sum of the weight and the difference distance in which the numbers of digits are combined, or a smaller value of the weight and the difference distance in which the numbers of digits are combined with each other. But you can.

  The position estimation device 2 </ b> B records the result determined by the error determination unit 23 in the position information master database 4 together with the estimated coordinates of the beacon 8 calculated by the position estimation unit 22.

  FIG. 14 is a diagram for explaining the processing content of each functional block of the position estimation device 2B according to the present embodiment. Here, the processing by the data acquisition unit 20, the trajectory extraction unit 21, and the position estimation unit 22 and the information collected or derived by these are the same as those in the first embodiment, and a description thereof will be omitted.

  The error determination unit 23 acquires the estimated coordinates of the beacon 8 and the interpolation coordinates and weights of the terminal 6 as described above, calculates an error score based on these, and determines whether the error score is greater than a threshold value. . In the estimation of the installation position of the beacon 8 having a certain identifier, the error determination unit 23 determines that the estimated coordinates of the beacon 8 calculated by the position estimation unit 22 are inaccurate when the error score of at least one terminal 6 is larger than the threshold. It is determined that Further, the error determination unit 23 generates error determination information including the result of such determination. Referring to the error determination information shown in FIG. 14, it can be seen that the estimated coordinates of the beacon 8 with the identifier p1 are determined to have an error. In addition, the determination result “−” in the case of the beacon 8 with the identifier p2 indicates that there is no error in estimating the position of the beacon 8. Note that the data stored in the error determination information as a determination result indicating that there is no error in estimating the position of the beacon 8 is not particularly limited as long as it is data indicating no error, such as an initial value or a Nill value.

  FIG. 15 is a flowchart of processing by the position estimation device 2B according to the present embodiment. In the flowchart, the subject of each process from step S100 to step S102 and the content of the process are the same as in the case of the first embodiment described with reference to FIG. In step S103, processing by the error determination unit 23 of the position estimation device 2B is executed.

  FIG. 16 is a flowchart of processing by the error determination unit 23 in the present embodiment. The error determination unit 23 is a difference distance that is a distance between the estimated position of the beacon 8 obtained by the position estimation unit 22 in step S102 and the estimated position of the terminal 6 used for estimating the installation position of the beacon 8. Is calculated (step S300). Subsequently, the error determination unit 23 calculates an error score using the difference distance calculated in step S300 and the weight calculated by the position estimation unit 22 in step S202 (FIG. 10) in step S102 (step S301). The error determination unit 23 compares the calculated error score with a threshold value. If the error score is larger than the threshold, the error determination unit 23 determines that the estimated coordinates of the beacon 8 calculated in step S203 in step S102 are incorrect. If not, the error determination unit 23 estimates the position of the beacon 8. It is determined that there is no mistake (step S303). The error determination unit 23 stores the error determination result by the processing in step S303 in the position information master database 4.

  FIG. 17 is a diagram for describing an example of an error determination process performed by the position estimation device 2B according to the present embodiment. Here, consider a case where the position estimation device 2B acquires the position time information and the reception information shown on the left in FIG. The position time information here is equal to the position time information illustrated in FIG. 8 for the explanation of the processing by the position estimation apparatus 2A according to the first embodiment. The received information here is the same as the received information illustrated in FIG. 8 for the explanation of the processing by the position estimation device 2A, except for the identifier. In the reception information in FIG. 17, it is assumed that the identifier included in the information related to the signal from the beacon 8 received by the terminals 6 having IDs 1 to 6 is p1.

  The data acquisition unit 20 of the position estimation device 2B reads the position time information and the reception information shown on the left in FIG. 17 from the movement history database 3 by the process in step S100 (FIG. 7) in the first embodiment. In step S101, the locus extraction unit 21 generates locus extraction information from the position time information and the reception information. The position estimation unit 22 derives a determination result as to whether correction is to be performed by the processing in step S200 (FIG. 10) described above. Further, based on the determination result, the position estimation unit 22 appropriately corrects the second time interval of each terminal 6 in step S201 described above. Then, the position estimation unit 22 uses the first and second time intervals after correction when the correction is performed, and the original first and second time intervals when the correction is not performed. Interpolated coordinates are calculated. Further, in step S202, the position estimation unit 22 uses the distance between the first point and the second point, the short time interval, and the strength of the signal received from the beacon 8, and linear interpolation coordinates of each terminal 6. The weight added to is calculated. In step S <b> 203, the position estimation unit 22 calculates the weighted average of the linear interpolation coordinates of the terminals 6 having IDs 1 to 6 used for the beacon 8 with the identifier p <b> 1, and uses this as the estimated coordinates of the beacon 8.

  In the case illustrated in FIG. 17, the estimated coordinates of the beacon 8 with the identifier p1 are calculated as (55.4, 39.6).

  FIG. 18 is a diagram for describing an example of an error determination process performed by the position estimation device 2B according to the present embodiment. The error determination unit 23 acquires the estimated coordinates (55.4, 39.6) of the beacon 8 with the identifier p1 and the linear interpolation coordinates of each terminal 6 from ID1 to ID6, and calculates the difference distance between these ( Step S300). In the example shown in FIG. 18, the difference distance value in the case of ID1 is 60.2, and the difference distance in the case of ID2 is 25.4.

  Using the calculated difference distance, the error determination unit 23 calculates an error score for each ID (step S301). In FIG. 18, the error score for ID1 is 26.9, and the error score for ID2 is 2.5.

  Next, the error determination unit 23 determines whether or not the error score for each ID calculated in step S301 is greater than a threshold value. If at least one of the error scores in the case of the same identifier is larger than the threshold value, the error determination unit 23 determines that the estimated coordinates of the beacon 8 of the identifier calculated by the position estimation unit 22 are incorrect (step S302). ).

  In the case of FIG. 18, if the threshold is 7, the error score 26.9 in the case of ID1 is larger than the threshold 7. Thereby, it can be seen that the estimated coordinates of the beacon 8 of the identifier p1 obtained by performing the weighted calculation using the linear interpolation coordinates of the terminal 6 of ID1 are highly likely to be incorrect. The error determination unit 23 generates error determination information as illustrated in the lower right of FIG. 18 and stores this in the position information master database 4.

  FIG. 19 is a diagram illustrating an example of an effect obtained by performing the error determination process in the present embodiment. Here, the results of the position estimation process and the error determination process are shown based on the reception information and position time information shown in FIG. The lines, circles, marks, etc. in FIG. 19 are the same as those described above.

  The estimated position of each terminal 6 is shown in the upper left of FIG. Here, two beacons 8 having the same identifier p1 are shown.

  In the upper right part of FIG. 19, the estimated position of the beacon 8 of the identifier p1 obtained by the weighted average is shown. In addition, the number beside the mark indicating the signal from the beacon 8 estimated that each terminal 6 has received at the estimated position represents the weight. For example, in the case of ID1, the weight is 0.45. Here, the weight in the case of ID1 is larger than the weight in the case of other IDs even though the estimated position of the terminal 6 of ID1 is far from the estimated position of the beacon 8. The weight should be larger as it is closer to the beacon 8, thereby causing a question as to whether the signal received by the terminal 6 with ID 1 is from the beacon 8 located at the estimated coordinates calculated by the position estimation unit 22.

  Further, the error determination process will be described with reference to the lower diagram of FIG. Here, among the numbers beside the mark indicating the signal from the beacon 8, those outside [] represent the weight, and those inside [] represent the error score. For example, in the case of ID1, the weight is 0.45 and the error score is 26.9. The error score for ID1 is greater than the threshold value 25. Similarly, the error scores for IDs 5 and 6 are also larger than the threshold. For this reason, it can be recognized that the estimated position of the beacon 8 obtained by the position estimation unit 22 may be incorrect. As a result, the position estimation device 2B can prevent erroneous information from being stored in the position information master database 4 as correct information.

(Third embodiment)
The position estimation device 2B according to the second embodiment takes into consideration the case where two or more beacons 8 having the same identifier exist, and determines whether or not the position of the beacon 8 estimated by itself is correct. be able to. However, even if the position estimation device 2B can determine that there is an error in the estimated position of the beacon 8, it cannot estimate the installation positions of two or more beacons 8 having the same identifier. The position estimation device 2C according to the present embodiment can estimate the installation positions of two or more beacons 8 having the same identifier, in addition to being able to determine whether or not the estimated position of the beacon 8 is correct. .

  FIG. 20 is a diagram illustrating an example of the configuration of the position estimation system 1C according to the present embodiment. The position estimation system 1 </ b> C includes the terminal 6, the sensor 7, the beacon 8, the movement history database 3, and the position information master in the first and second embodiments described above and the etabase 4. Since these are the same as those in the above embodiment, the description thereof is omitted. The beacon 8 is a legitimate beacon 8T or a spoofed beacon 8F. The position estimation system 1C includes a position estimation device 2C. The connection relationship between devices included in the system is the same as the connection relationship in the above embodiment regardless of the reference numerals.

  The position estimation device 2C includes a data acquisition unit 20, a trajectory extraction unit 21, and a position estimation unit 22, similarly to the position estimation devices 2A and 2B in the above embodiment. In addition to these, the position estimation device 2 </ b> C includes an error position estimation unit 24. Here, the functional blocks other than the error position estimation unit 24 in the position estimation apparatus 2C are the same as those in the above embodiment, and thus description thereof is omitted. However, although the position estimation unit 22 in the above embodiment is connected to the position information master database 4, the position estimation unit 22 in this embodiment may not be connected to the position information master database 4. The error position estimation unit 24 is connected to the position estimation unit 22 and the position information master database 4.

  The error position estimation unit 24 acquires the estimated coordinates of the beacon 8, the interpolation coordinates of the terminal 6, and the weight to each interpolation coordinate calculated by the position estimation unit 22. Based on these, the error position estimation unit 24 calculates each estimated coordinate of a plurality of beacons 8 having the same identifier as described later. The error position estimation unit 24 is connected to the position information master database 4 and outputs the calculated estimated coordinates of the beacon 8 to the position information master database 4.

  FIG. 21 is a diagram for explaining the processing content of each functional block of the position estimation device 2C according to the present embodiment. Here, each process by the data acquisition unit 20, the trajectory extraction unit 21, and the position estimation unit 22 and information collected or derived by these functional blocks are the same as those in the first and second embodiments. Description is omitted.

  The error position estimation unit 24 acquires the weights to be assigned to the estimated positions of the beacon 8 and the terminal 6 and the interpolation coordinates of the terminal 6 calculated by the position estimation unit 22. The error position estimation unit 24 calculates the estimated coordinates of each of these beacons 8 when there are a plurality of beacons 8 having the same identifier, using the acquired information. In the lower right of FIG. 21, the estimated coordinates of the beacon 8 calculated by the error position estimating unit 24 are shown. It can be seen that there are two beacons 8 with the identifier p1, and that these estimated coordinates are X'1-1 and X'1-2.

  FIG. 22 is a flowchart of processing by the position estimation device 2C according to the present embodiment. Here, the processing from step S100 to step S102 is the same as in the case of the above-described embodiment, and thus description thereof is omitted. However, in step S102, the position estimation unit 22 in the above embodiment outputs the estimated coordinates of the beacon 8 to the position information master database 4, but from the position estimation unit 22 according to the present embodiment to the position information master database 4. There is no such output. However, the present invention is not limited to this, and the estimated coordinates of the beacon 8 may be output from the position estimation unit 22 to the position information master database 4. In this case, after the output by the position estimation unit 22, the error position estimation unit 24 outputs the estimated coordinates of the beacon 8 to the position information master database 4, and the position information master database 4 updates the estimated coordinates of the beacon 8 based on this. May be. Alternatively, when the error score of the terminal 6 used for estimating the position of the beacon 8 with a certain identifier is larger than the threshold, the error position estimation unit 24 uses the position information master to calculate the estimated coordinates of the beacon 8 with the identifier. You may output to the database 4.

  FIG. 23 is a flowchart of the process (step S104 in FIG. 22) by the error position estimation unit 24 in the present embodiment. 24, 25, 26, and 27 are diagrams illustrating an example of error position estimation processing in the present embodiment. Hereinafter, the error position estimation process will be described with reference to FIGS. 23 and 24 to 27. 24 to 27 relate to the error position estimation process when the position estimation apparatus 2C reads the position time information and the reception information shown on the left in FIG.

  The error position estimation unit 24 calculates a difference distance from the estimated coordinates of the beacon 8 and the terminal 6 calculated by the position estimation unit 22 using the trajectory information (step S400). Referring to FIG. 24, for example, the difference distance in the case of ID1 is obtained as 60.2, and the difference distance in the case of ID2 is obtained as 25.4.

  Returning to FIG. Subsequent to step S400, the error position estimation unit 24 calculates an error score (step S401). Referring to FIG. 24, it can be seen that the error position estimation unit 24 calculates an error score of 26.9 for ID1 and 2.5 for ID2.

  Returning to FIG. Subsequent to step S401, the error position estimation unit 24 determines whether the error score of each terminal 6 is greater than a threshold (step S402).

  Referring to FIG. 24, in the case of ID1, the error score is 26.9, which is larger than the threshold value of 7. Therefore, the error position estimation unit 24 assumes that the signal received by the terminal 6 with ID1 is from the beacon 8 estimated to be installed at a position corresponding to the coordinates (55.4, 39.5). Is determined to be erroneous. Accordingly, in the trajectory information illustrated in FIG. 24, the determination result in the case of ID1 is “error”. Similarly, in the case of ID2, the error score is 2.5, which is smaller than the threshold value of 7. For this reason, it is determined that there is a high possibility that the signal received by the terminal 6 of ID2 is from the beacon 8 estimated to be at a position corresponding to the coordinates (55.4, 39.5). For this reason, in the trajectory information illustrated in FIG. 24, the determination result in the case of ID2 is indicated by “−”.

  Returning to FIG. Subsequent to step S402, when there is a terminal 6 whose error score is larger than the threshold for the beacon 8 of a certain identifier (step S403: Yes), the error position estimation unit 24 determines the terminal 6 having the highest error score. The estimated position (interpolated coordinates) is classified into another cluster (step S404). Subsequently, the error position estimation unit 24 calculates a weighted average of the interpolation coordinates of the terminal 6 for each cluster. The position corresponding to the coordinates obtained by the calculation is also described as the center of gravity. The error position estimation unit 24 calculates a distance between the estimated position of each terminal 6 and the center of gravity of each cluster (the distance is also described as a difference distance). Then, the error position estimation unit 24 reclassifies the estimated position of the terminal 6 into a cluster having the smallest difference distance between the estimated position of the terminal 6 and the center of gravity (step S406). The error position estimation unit 24 determines whether or not the classification destination of the estimated position of each terminal 6 has changed before and after step S406, and if it has changed (step S407: Yes), returns to the process of step S405. . On the other hand, if the classification destination of the interpolated coordinates of each terminal 6 has not changed before and after step S406 (step S407: No), the error position estimating unit 24 returns to the process of step S400. Note that the error position estimating unit 24 may return to the process of step S401 instead of returning to the process of step S400.

  The process of step S404 will be described with reference to FIG. FIG. 25 shows processing following the processing specifically illustrated in FIG. Referring to the determination result of the trajectory information shown in the upper part of FIG. 25, “error” exists (step S403: Yes). As a result, the error position estimation unit 24 classifies the interpolation coordinates (8.8, 77.7) of the terminal 6 with ID 1 having the highest error score of 26.9 into another cluster (step S404). In the case of FIG. 25, the cluster name is associated with the identifier of the beacon 8, but the cluster into which the interpolation coordinates (8.8, 77.7) are classified is defined as p1-2, and other interpolation coordinates are included. The cluster is designated as p1-1. Next, the error position estimation unit 24 calculates the weighted average of the interpolation coordinates in each of the clusters p1-1 and p1-2, and the coordinates (76.1, 22.5) of the center of gravity of the cluster p1-1 and the cluster The coordinates (8.8, 77.7) of the center of gravity of p1-2 are obtained (step S405).

  In FIG. 25, the error position estimation unit 24 further calculates a difference distance between the estimated position of the terminal 6 corresponding to each linear interpolation coordinate and the center of gravity of each cluster, and the estimated position of each terminal 6 is calculated based on the difference distance. Reclassify into smaller clusters. The trajectory information shown in the lower part of FIG. 25 indicates the difference distance between the estimated position of each terminal 6 and each center of gravity. For example, the estimated position of the terminal 6 corresponding to the interpolation coordinates (30, 40), the cluster The difference distance from the center of gravity of p1-1 is 49.3. The distance between the estimated position of the terminal 6 and the center of gravity of the cluster p1-2 is 43.2. From this, it can be seen that the estimated position of the terminal 6 is closer to the center of gravity of the cluster p1-2 than the center of gravity of the cluster p1-1. For this reason, the error position estimation unit 24 reclassifies the estimated position of the terminal 6 into the cluster p1-2 (step S406). Referring to the classification destination clusters of the interpolation coordinates (30, 40) in the upper and lower trajectory information in FIG. 25, the clusters are classified into clusters p1-1 and p1-2 before and after step S405, respectively. It can be seen that a change has occurred (step S407).

  FIG. 26 is a continuation of the processing by the error position estimating unit 24 shown in FIG. 25, and the error position estimating unit 24 when the processing moves from step S407 to step S405 (step S407: Yes in FIG. 23). The content of the processing by is shown. The error position estimation unit 24 recalculates the weighted average of each interpolated coordinate in each of the clusters p1-1 and p1-2 using the reclassified trajectory information shown in the upper part of FIG. 26 (step S405). . As a result, the coordinates of the center of gravity of each of the clusters p1-1 and p1-2 are (81.2, 20.6) and (12.7, 70.8) as shown in the middle of FIG. The error position estimation unit 24 calculates again the distance between the estimated position of the terminal 6 corresponding to each interpolation coordinate and each center of gravity. Thus, for example, the difference distance between the estimated position of the terminal 6 corresponding to the interpolation coordinates (30, 40) and the center of gravity of the cluster p1-1 is 54.8, and the estimated position of the terminal 6 and the cluster p1-2 The difference distance from the center of gravity is 35.4. The error position estimation unit 24 classifies each interpolated coordinate into a cluster having a small difference distance from the center of gravity. In the lower part of FIG. 26, trajectory information storing the results when classification is performed again for each interpolation coordinate is shown. Here, it can be seen that there is no change in the classification result of the interpolated coordinates after the processing of the immediately preceding step S405 (step S407: No in FIG. 23). Thereby, the error position estimation part 24 returns a process to step S400.

  FIG. 27 shows the continuation of the processing by the error position estimation unit 24 shown in FIG. The error position estimation unit 24 uses the coordinates of the center of gravity of each cluster shown in the middle part of FIG. 27, and the difference distance between the estimated position of the terminal 6 and the center of gravity of the cluster into which the interpolation coordinates of the terminal 6 are classified. Is calculated (step S400). The error position estimation unit 24 may update the difference distance in the trajectory information by using a shorter one of the difference distances calculated in step S406 instead of calculating the difference distance in step S400. At this time, the error position estimation unit 24 may delete the longer one of the difference distances calculated in step S406. In the case of ID1, for example, in the trajectory information shown in the upper part of FIG. 27, a difference distance of 7.9 is shown.

  The error position estimation unit 24 calculates an error score from the difference distance and weight in each ID obtained in the immediately preceding step S400 (step S401). In FIG. 27, in the case of ID1, it can be seen that the error score is 3.5. The error score is smaller than 7, which is a threshold value. Similarly, in each case of ID2, 3, 4, 5, and 6, it can be seen that the error score is equal to or less than the threshold value. Thereby, the error position determination unit 24 determines that there is no error score greater than the threshold (No in step S403). At this time, the coordinates (81.2, 20.6) and (12.7, 70.8) of the center of gravity of each cluster calculated in the immediately preceding step S405 are used as the estimated coordinates of the two beacons 8 whose identifiers are p1. Can be considered. Thereby, the contradiction that the beacon 8 that is said to have transmitted the signal received by the terminal 6 exists in the distance despite the large weight is resolved.

  Also, here, in step S404, the interpolation coordinates of one terminal 6 having the highest error score are separated from each estimated position of two or more terminals 6 having an error score greater than the threshold value, as a group. Classified into clusters. This is because even if the estimated positions of two or more terminals 6 are grouped together into another cluster, these terminals 6 do not always receive signals from the same beacon 8. Then, in step S404, one interpolated coordinate is classified into another cluster for each processing in step S403, and subsequent processing is performed to collect a situation in which an error score exceeding the threshold value is generated. Are organized into clusters to be classified.

  When there is no error score greater than the threshold (step S403: No), the error position estimation unit 24 outputs the calculated estimated position of the beacon 6 to the position information master database 4 and ends the process. Accordingly, the position estimation device 2C ends the series of processes as shown in FIG.

  FIG. 28 is a diagram illustrating an example of an effect obtained in position estimation by the position estimation device 2C according to the present embodiment. The weights, error scores, estimated travel routes, estimated beacon positions, etc. of each terminal 6 shown in the left diagram of FIG. 28 are the same as in FIG. The process illustrated in FIG. 28 shows a case where the error position estimation unit 24 performs a process using the trajectory information in FIGS. The diagram shown on the left side of FIG. 28 shows a state in which the error score of each terminal 6 is first calculated after the error position estimating unit 24 starts processing. In the case of ID1, the error score is 26.9, which is larger than the threshold 7 and is the highest value among the error scores in ID1 to ID6. Thereby, as shown in the middle of FIG. 28, the estimated position in the case of ID1 is divided into clusters different from the estimated positions of the terminals 6 of other IDs. If the center of gravity for each cluster is considered as the estimated position of the beacon 8 at this time, the estimated position of the beacon 8 in the cluster p1-2 in the middle diagram of FIG. 28 is equal to the estimated position of the terminal 6 of ID1. The estimated position of the beacon 8 in the cluster p1-1 is the position indicated by the graphic indicating the estimated position of the other beacon 8 in the middle diagram of FIG. In this case, when the error score is calculated, it is a number in [] in the middle diagram of FIG. For example, the error score in the case of ID2 of linear coordinates (30, 40) is the difference distance 49.3 between the center of gravity of the cluster p1-1 and the estimated position of the terminal 6 of ID2 from the trajectory information shown in the lower part of FIG. And 4.9, the product of the weight 0.1.

  The error position estimation unit 24 further classifies the estimated position of the terminal 6 of each ID so that the distance from the center of gravity becomes smaller. The center of gravity of each cluster calculated based on the classification is indicated by the mark of the estimated position of the beacon 8 in the right diagram of FIG. In addition, the error score of each terminal 6 is shown in [] in this figure, and it can be seen that all the error scores are below the threshold value. As a result, it can be seen that the position of the center of gravity of each cluster corresponds to the estimated position of each of the two beacons 8 having the same identifier.

  As described above, according to the position estimation device 2C according to the present embodiment, even when two or more beacons 8 having the same identifier exist, the position of each of these beacons 8 is estimated without degrading accuracy. Can do.

(Other embodiment 1)
The position estimation devices 2 </ b> A, 2 </ b> B, and 2 </ b> C according to the above embodiment estimated the position of the beacon 8 based on the reception information and the position time information from the terminal 6 that has received signals from the beacon 8 and the sensor 7. The position estimation device 2D according to the present embodiment uses data in SNS (social networking service) including a word as a keyword instead of the reception information based on the signal from the beacon 8. The word used as the keyword here is, for example, a dish name such as “ramen” or “pasta”, or a product name such as “sole” or “shoes”. Here, data including such words is referred to as SNS data.

  FIG. 29 is a diagram illustrating a position estimation method according to another embodiment. Here, the position estimation device 2D reads SNS data from the cloud or the like instead of the reception information described above. The SNS data shown in FIG. 29 includes the ID of the terminal 6 used for inputting the word included in the SNS data, the time when the word was written on the SNS home page, the character data of the word, Contains the reliability of the input content. The reliability of the input content is a numerical value indicating how reliable the content written from the terminal 6 is. The reliability can vary depending on the terminal 6 and can also vary depending on the written contents. The reliability corresponds to the strength of the signal from the beacon 8 in the above embodiment, and therefore, the reliability is also described as strength below.

  In the above embodiment, the time at which the terminal 6 receives a signal from a transmitter such as the beacon 8 is set as the reception time. However, here, the time at which the word is written on the SNS home page or the person who wrote the word writes it. The time at which the information that triggered the acquisition is acquired corresponds to this. Therefore, these times are collectively described as reception times.

  In addition, the signal from the beacon 8 in the above embodiment corresponds to information on a store that the person who wrote to the SNS finds during movement or the like. In the present embodiment, a store or the like corresponds to the beacon 8 or the like in the above embodiment.

  Referring to the SNS data shown in FIG. 29, it can be seen that the word “ramen” is written on the SNS home page from the terminals 6 of IDs 1, 2, and 3 at times 7, 30, and 40, respectively. Further, it can be seen that the reliability of the writing from the terminal 6 with ID 1, 2, 3 is 70, 100, 90, respectively. The position estimation device 2D estimates the location of the ramen shop, for example, using these SNS data and position time information.

  First, the position estimation device 2D generates information that corresponds to the above-described trajectory extraction information, and that summarizes the position time information and SNS data for each ID and arranges these in ascending order of time. At this time, the position estimation device 2D combines the position time information relating to the time immediately before and after the time of the SNS data and the SNS data. Information generated in this way also describes trajectory extraction information.

  Similarly to the above-described embodiment, the position estimation device 2D has the movement path of the terminal 6 of each ID and the estimated position of the terminal 6 at the reception time, that is, the position where the word is estimated to be written on the SNS homepage (writing (Also referred to as estimated position). 29 shows the derived movement route of each terminal 6 and the estimated writing position of each terminal 6 in the figure shown on the left from the middle of the upper stage of FIG. Here, it is presumed that “ramen” was written on the SNS homepage at the cloud mark point where hatching was not performed, and “pasta” was the SNS homepage at the cloud mark point where hatching was performed. Presumed to have been written above.

  The position estimation device 2D calculates a weighted average for each word for these estimated writing positions, and estimates the position of a store or the like related to the word. The weights in this embodiment are defined in the same way as in the above embodiment. The word here corresponds to the identifier of the beacon 8 in the above embodiment.

  In the upper right of FIG. 29, a specific example of the estimation result is shown. Here, (14.1, 68.7) are obtained as the coordinates of the estimated position of the ramen shop.

  FIG. 30 is a diagram illustrating functional blocks of the position estimation device 2D according to the present embodiment. Each functional block of the position estimation device 2D according to the present embodiment is the same as the functional block of the position estimation device 2A according to the first embodiment. However, the data acquisition unit 20 in the present embodiment is connected to the cloud or the like in addition to the movement history database 3 and the position information master database 4 or directly connected to the network 5.

  In addition to the position information master database 4, the position estimation unit 22 may be connected to the cloud or the like or directly connected to the network 5. Alternatively, the position information master database 4 may be connected to the network 5, for example, a database in the cloud.

  Processing related to position estimation by the position estimation device 2D according to the present embodiment is the same as that shown in FIGS. However, the data acquisition unit 20 acquires SNS data instead of the reception information in step S100. Moreover, the position estimation part 20 estimates the position of the shop etc. which provide the thing etc. which a word means instead of the process of step S203 of FIG. 10, and calculates the coordinate. In step S203, the position estimation unit 22 may store the estimated position of the store or the like in the cloud or the like instead of the position information master database 4.

  According to the position estimation apparatus 2D according to the present embodiment, the user of the terminal 6 sees the provided product from the store or the like while moving and writes the data written on the homepage of the SNS, It can be effectively used for estimating the position of the store or the like. As a result, it is possible to provide the user having the terminal 6 connected to the network 5 with information on the location of the target store and where to obtain the target product.

(Other embodiment 2)
In the other embodiment 1 described above, there are the following problems when there are a plurality of stores that provide the same product or the like. As a result of the same word being written on the SNS homepage by each user of one or more terminals 6 that passed in front of a plurality of stores, etc., SNS data that should be related to a plurality of stores, etc. Can be treated. The estimated coordinates of the store or the like calculated by the position estimation device 2D using such SNS data may be different from the actual position.

  The position estimation device 2E according to the present embodiment estimates the position of each of a plurality of stores that provide the same product or the like.

  The position estimation apparatus 2E according to the present embodiment acquires position time information and SNS data acquired by the position estimation apparatus 2D according to the other embodiment 1 described above. Then, the position estimation device 2E creates trajectory extraction information based on these, and estimates the position of a store or the like as in the above embodiment. At this time, the distance between the estimated position at the reception time of the terminal 6 used for estimating the position of the store or the like and the estimated position of the store or the like (the distance is also described as the difference distance) and the weight are secondly calculated. The error score similar to that in the third embodiment is calculated. And the position of several stores etc. matched with the same word is estimated similarly to 3rd Embodiment.

  FIG. 31 is a diagram illustrating functional blocks of the position estimation device 2E according to the present embodiment. Each functional block of the position estimation device 2E according to the present embodiment is the same as the functional block of the position estimation device 2C according to the third embodiment. However, the data acquisition unit 20 in the present embodiment may be connected to the cloud or the like in addition to the movement history database 3 and the position information master database 4 or may be directly connected to the network 4.

  In addition to the position information master database 4, the error position estimation unit 24 in the present embodiment may be connected to a cloud or the like, or may be directly connected to the network 5. Alternatively, the position information master database 4 may be connected to the network 5, for example, a database in the cloud.

  Processing related to position estimation by the position estimation device 2E according to the present embodiment is the same as that shown in FIGS. However, the data acquisition unit 20 in the present embodiment acquires SNS data instead of the reception information in step S100. Further, the position estimation unit 22 in the present embodiment calculates the coordinates of the estimated position of a store or the like that provides an object or the like that means a word instead of obtaining the coordinates of the estimated position of the beacon 8 instead of the process of step S102. To do. The processing in step S104 by the error position estimation unit 24 in the present embodiment is performed by using the estimated position coordinates of a plurality of stores and the like associated with the same word instead of the estimated position coordinates of the beacon 8 calculated in the above embodiment. calculate. Further, in the case where there is no error score larger than the threshold value in step S403, the error position estimation unit 24 in the present embodiment replaces the estimated position of the beacon 8 with the position information master database 4 or the cloud instead of the estimated position coordinates of the beacon 8. Remember.

  FIG. 32 is a diagram illustrating an example of processing by the position estimation device 2E according to the present embodiment. The position estimation device 2E acquires position time information and SNS data shown on the left in FIG. This position time information is the same as that in the above embodiment. The SNS data is the same as the SNS data in the above embodiment except for the word, and all the words are “ramen”.

  In the figure on the left side from the center of the upper stage in FIG. In the upper right diagram in FIG. 32, the estimated positions of the plurality of ramen shops derived by the error position estimating unit 24 are shown. Here, it can be seen that there are two ramen shops that triggered the word “ramen” on the SNS website. It can be seen that (82.2, 20.6) was calculated as one estimated coordinate of these ramen stores and (12.7, 70.8) was calculated as the estimated coordinate of the other.

  According to the position estimation device 2E according to the present embodiment, even when there are a plurality of stores that provide the same product or the like, the position of each of the plurality of stores is estimated using short words in the SNS data. be able to.

(Other embodiment 3)
In the above embodiment, the position of the fixed beacon 8 or the store is estimated based on information received from the moving terminal 6 or the like. However, the position estimation device 2A or the like may estimate the position of the mobile terminal instead of the fixed beacon 8 by using a receiver such as a fixed gateway instead of the terminal 6. In this case, a receiver such as a fixed gateway corresponds to the terminal 6 in the above embodiment, and a mobile terminal corresponds to a transmitter such as the beacon 8 in the above embodiment. The sensor 7 used at this time may or may not be fixed as long as the position is specified.

(Other embodiment 4)
In the above embodiment, the average moving speed of the terminal 6 is calculated, and it is determined whether or not the terminal 6 has a stay. However, when the sensor 7 or the beacon 8 can acquire information such as the relative speed and the relative direction with the terminal 6, the terminal 6 acquires such information from the sensor 7 or the beacon 8. Also good. The position estimation device 2 </ b> A or the like that has acquired information such as the relative speed from the terminal 6 may use this for estimation of the position of the beacon 8.

  FIG. 33 is a diagram illustrating an example of a hardware configuration for realizing each function of each position estimation apparatus according to the first, second, and third embodiments and the other embodiments 1, 2, 3, and 4. In addition, here, each position estimation apparatus has hardware as a general computer, and the process by each position estimation apparatus is performed by specifically using the hardware 9 shown below. The hardware 9 includes a processor 91, a memory 92, a storage device 93, a network interface circuit 94, and an input device 95 that are connected to each other by a bus 90.

  The processor 91 is, for example, a single core, dual core, or multi-core processor.

  The memory 92 is, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), or a semiconductor memory.

  The processor 91 executes various programs stored in the memory 92 using information stored in the memory 92 or information read from the storage device 93 into the memory 92, whereby the locus extraction unit 21 and the position estimation unit 22 are executed. The function is realized. Similarly, the functions of the error determination unit 23 in the second embodiment and the error position estimation unit 24 in the third embodiment are realized by the processor 91 and the memory 92 or the processor 91 and the memory 92 and the storage device 93. Can.

  The storage device 93 is, for example, a hard disk drive or an optical disk device, and may be an external storage device or a portable storage medium. The movement history database 3 and the position information master database 4 may be realized by the storage device 93.

  The network interface circuit 84 is an interface for enabling the position estimation device to communicate with other nodes via a LAN (Local Area Network), the Internet, an intranet, or the like. When the movement history database 3 or the position information master database 4 exists outside the position estimation device, or when the position estimation device collects information from the cloud or the like, the network interface circuit 23 collects data from the data acquisition unit 20. Function is realized. When the data acquisition unit 20 selects the beacon 8 whose position is to be estimated, the function of the data acquisition unit 20 is realized by the processor 91, the memory 92, and the like.

  The input device 95 is, for example, a keyboard or a touch panel, and is used for the user to select a beacon 8 whose position is to be estimated and to input an identifier of the beacon 8. Note that the input device 95 may be omitted when the position estimation device automatically eliminates the line t from the beacon 8 whose position is to be estimated.

  In addition to the cases described above, all or some of the functional blocks in FIGS. 1, 13, 20, 30, and 31 can be realized by dedicated hardware as appropriate.

Regarding the embodiments including the above-described Embodiments 1 to n, the following additional notes are further disclosed.
(Appendix 1)
The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal An acquisition unit for acquiring position time information and second position time information acquired at a second point by the terminal at a second time after the reception time;
An average moving speed between the first point and the second point of the terminal is calculated from the first position time information and the second position time information, and the average moving speed is less than a predetermined value. And when the distance between the first point and the second point is a predetermined distance or more, a first time interval between the first time and the reception time, Correction is performed on at least one of the second time intervals between the reception time and the second time, and at least one of the first time interval and the second time interval after the correction is performed. A position estimation unit that estimates the position of the terminal at the reception time and estimates the position of the transmitter based on the estimation;
A position estimation apparatus comprising:
(Appendix 2)
The position estimation apparatus according to appendix 1, wherein the position estimation unit performs the correction on the second time interval.
(Appendix 3)
The position estimation unit
When the average moving speed is less than or equal to a predetermined value and the distance between the first point and the second point is less than a predetermined distance, the correction is performed, and the first after the correction The position of the terminal (6) at the reception time is estimated based on at least one of the time interval and the second time interval.
The position estimation apparatus according to Supplementary Note 1 or 2, characterized in that:
(Appendix 4)
The position estimation unit
When the average moving speed is less than or equal to a predetermined value and the distance between the first point and the second point is less than a predetermined distance, the correction is not performed and the first time Estimating the position of the terminal at the reception time based on at least one of an interval and the second time interval;
The position estimation apparatus according to Supplementary Note 1 or 2, characterized in that:
(Appendix 5)
The position estimation unit
In the case of performing the correction, the position of the terminal at the reception time is estimated by performing linear interpolation using at least one of the first time and the second time after the correction,
When the correction is not performed, the position of the terminal at the reception time is estimated by performing linear interpolation using at least one of the first time and the second time.
The position estimation apparatus according to any one of appendices 1 to 4, characterized in that:
(Appendix 6)
The position estimation unit
In the case of performing the correction, the position of the terminal at the reception time is estimated based on a shorter time interval between the first time interval and the second time interval after the correction,
When the correction is not performed, the position of the terminal at the reception time is estimated based on a shorter time interval out of the first time interval and the second time interval.
The position estimation apparatus according to any one of appendices 1 to 5, characterized in that:
(Appendix 7)
The position estimation unit
A weight is applied to the estimated position coordinates of the terminal to calculate the position coordinates of the transmitter;
The weight is
When the correction is performed by the position estimation unit, it is calculated using at least one of the first time interval and the second time interval after the correction,
When the correction is not performed by the position estimation unit, it is calculated using at least one of the first time interval and the second time interval.
The position estimation device according to any one of appendices 1 to 6, characterized in that:
(Appendix 8)
The position according to appendix 7, wherein the weight is further calculated using at least one of the signal strength and the distance between the first point and the second point. Estimating device.
(Appendix 9)
The position estimation device further includes:
Calculating the difference distance between the estimated position of the transmitter and the estimated position of the terminal used to estimate the position of the transmitter;
An error determination unit that calculates an error score based on the difference distance and the weight, and determines that the signal is not transmitted from the transmitter when the error score is greater than a threshold value;
The position estimation apparatus according to appendix 7 or 8, characterized by comprising:
(Appendix 10)
The position estimation device further includes an error position estimation unit,
The error position estimation unit includes:
Calculating a difference distance between the estimated position of the transmitter and each estimated position of one or more of the terminals used for estimating the position of the transmitter;
For each terminal, calculate an error score based on the difference distance and the weight,
When at least one of the error scores of the one or more terminals is greater than a threshold, the signal received by the terminal having the highest error score among the error scores of the one or more terminals is the transmitter. It is determined that the call originated from a different transmitter,
Based on the estimated position of the terminal determined to have received the signal transmitted from the transmitter among the one or more terminals, the estimated position of the transmitter is derived again,
Deriving the estimated position of the other transmitter based on the estimated position of the terminal determined to have received the signal transmitted from the other transmitter among the one or more terminals,
The position estimation device according to appendix 7 or 8, characterized in that.
(Appendix 11)
The error position estimation unit includes:
Calculating a difference distance between each estimated position of the one or more terminals and the estimated position of the transmitter;
Calculating a difference distance between each estimated position of the one or more terminals and an estimated position of the other transmitter;
When the difference distance between the estimated position of the terminal and the estimated position of the transmitter is equal to or less than the difference distance between the estimated position of the terminal and the estimated position of the other transmitter, the terminal And determines that a signal has been received from the transmitter,
When the difference distance between the estimated position of the terminal and the estimated position of the transmitter is larger than the difference distance between the estimated position of the terminal and the estimated position of the other transmitter, the terminal And determines that a signal has been received from the other transmitter,
Based on the estimated position of the terminal determined to have received the signal transmitted from the transmitter among the one or more terminals, the estimated position of the transmitter is derived,
Deriving the estimated position of the other transmitter based on the estimated position of the terminal determined to have received the signal transmitted from the other transmitter among the one or more terminals,
The position estimation apparatus according to Supplementary Note 10, wherein:
(Appendix 12)
The error position estimation unit includes:
The terminal determined to have received a signal transmitted from the transmitter is classified into a first cluster, and the terminal determined to have received a signal transmitted from the other transmitter is defined as a second cluster. Classified into
Deriving the estimated position of the transmitter based on the estimated position of the terminal in the first cluster;
Deriving an estimated position of the other transmitter based on an estimated position of the terminal in the second cluster;
The position estimation apparatus according to Supplementary Note 10 or 11, characterized in that.
(Appendix 13)
The position estimation device according to any one of appendices 1 to 12, wherein the transmitter is a beacon.
(Appendix 14)
The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal Obtaining location time information and second location time information obtained at a second point at a second time after the reception time by the terminal;
From the first position time information and the second position time information, an average moving speed between the first point and the second point of the terminal is calculated,
Between the first time and the reception time when the average moving speed is not more than a predetermined value and the distance between the first point and the second point is not less than a predetermined distance At least one of the first time interval and the second time interval between the reception time and the second time, and the first time interval and the second time after the correction are corrected. Based on at least one of the time intervals, the position of the terminal at the reception time is estimated, and the position of the transmitter is estimated based on the estimation.
A position estimation program that causes a position estimation device to execute processing.
(Appendix 15)
The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal Obtaining location time information and second location time information obtained at a second point at a second time after the reception time by the terminal;
From the first position time information and the second position time information, an average moving speed between the first point and the second point of the terminal is calculated,
Between the first time and the reception time when the average moving speed is not more than a predetermined value and the distance between the first point and the second point is not less than a predetermined distance At least one of the first time interval and the second time interval between the reception time and the second time, and the first time interval and the second time after the correction are corrected. Based on at least one of the time intervals, the position of the terminal at the reception time is estimated, and the position of the transmitter is estimated based on the estimation.
A position estimation method executed by the position estimation apparatus.

DESCRIPTION OF SYMBOLS 1 Position estimation system 2A, 2B, 2C, 2D, 2E Position estimation apparatus 3 Movement history database 4 Position information master database 5 Network 6 Terminal 7 Sensor 8 Beacon 8F Impersonation beacon 8T Legitimate beacon 9 Hardware 20 Data acquisition part 21 Trajectory extraction Unit 22 position estimation unit 23 error determination unit 24 error position estimation unit 90 bus 91 processor 92 memory 93 storage device 94 network interface circuit 95 input device

Claims (15)

The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal An acquisition unit for acquiring position time information and second position time information acquired at a second point by the terminal at a second time after the reception time;
An average moving speed between the first point and the second point of the terminal is calculated from the first position time information and the second position time information, and the average moving speed is less than a predetermined value. And when the distance between the first point and the second point is a predetermined distance or more, a first time interval between the first time and the reception time, Correction is performed on at least one of the second time intervals between the reception time and the second time, and at least one of the first time interval and the second time interval after the correction is performed. A position estimation unit that estimates the position of the terminal at the reception time and estimates the position of the transmitter based on the estimation;
A position estimation apparatus comprising:   The position estimation apparatus according to claim 1, wherein the position estimation unit performs the correction on the second time interval. The position estimation unit
When the average moving speed is less than or equal to a predetermined value and the distance between the first point and the second point is less than a predetermined distance, the correction is performed, and the first after the correction Estimating the position of the terminal at the reception time based on at least one of the time interval and the second time interval;
The position estimation apparatus according to claim 1 or 2, wherein The position estimation unit
When the average moving speed is less than or equal to a predetermined value and the distance between the first point and the second point is less than a predetermined distance, the correction is not performed and the first time Estimating the position of the terminal at the reception time based on at least one of an interval and the second time interval;
The position estimation apparatus according to claim 1 or 2, wherein The position estimation unit
In the case of performing the correction, the position of the terminal at the reception time is estimated by performing linear interpolation using at least one of the first time and the second time after the correction,
When the correction is not performed, the position of the terminal at the reception time is estimated by performing linear interpolation using at least one of the first time and the second time.
The position estimation apparatus according to any one of claims 1 to 4, wherein the position estimation apparatus is characterized in that The position estimation unit
In the case of performing the correction, the position of the terminal at the reception time is estimated based on a shorter time interval between the first time interval and the second time interval after the correction,
When the correction is not performed, the position of the terminal at the reception time is estimated based on a shorter time interval out of the first time interval and the second time interval.
The position estimation apparatus according to any one of claims 1 to 5, wherein The position estimation unit
A weight is applied to the estimated position coordinates of the terminal to calculate the position coordinates of the transmitter;
The weight is
When the correction is performed by the position estimation unit, it is calculated using at least one of the first time interval and the second time interval after the correction,
When the correction is not performed by the position estimation unit, it is calculated using at least one of the first time interval and the second time interval.
The position estimation apparatus according to any one of claims 1 to 6, wherein   The weight is calculated using at least one of the signal strength and the distance between the first point and the second point. Position estimation device. The position estimation device further includes:
Calculating the difference distance between the estimated position of the transmitter and the estimated position of the terminal used to estimate the position of the transmitter;
An error determination unit that calculates an error score based on the difference distance and the weight, and determines that the signal is not transmitted from the transmitter when the error score is greater than a threshold value;
The position estimation apparatus according to claim 7 or 8, further comprising: The position estimation device further includes an error position estimation unit,
The error position estimation unit includes:
Calculating a difference distance between the estimated position of the transmitter and each estimated position of one or more of the terminals used for estimating the position of the transmitter;
For each terminal, calculate an error score based on the difference distance and the weight,
When at least one of the error scores of the one or more terminals is greater than a threshold, the signal received by the terminal having the highest error score among the error scores of the one or more terminals is the transmitter. It is determined that the call originated from a different transmitter,
Based on the estimated position of the terminal determined to have received the signal transmitted from the transmitter among the one or more terminals, the estimation of the estimated position of the transmitter is derived again,
Based on the estimated position of the terminal determined to have received the signal transmitted from the other transmitter among the one or more terminals, the estimated position of the another transmitter is derived.
The position estimation apparatus according to claim 7 or 8, wherein The error position estimation unit includes:
Calculating a difference distance between each estimated position of the one or more terminals and the estimated position of the transmitter;
Calculating a difference distance between each estimated position of the one or more terminals and an estimated position of the other transmitter;
When the difference distance between the estimated position of the terminal and the estimated position of the transmitter is equal to or less than the difference distance between the estimated position of the terminal and the estimated position of the other transmitter, the terminal And determines that a signal has been received from the transmitter,
When the difference distance between the estimated position of the terminal and the estimated position of the transmitter is larger than the difference distance between the estimated position of the terminal and the estimated position of the other transmitter, the terminal And determines that a signal has been received from the other transmitter,
Based on the estimated position of the terminal determined to have received the signal transmitted from the transmitter among the one or more terminals, the estimated position of the transmitter is derived,
Deriving the estimated position of the other transmitter based on the estimated position of the terminal determined to have received the signal transmitted from the other transmitter among the one or more terminals,
The position estimation apparatus according to claim 10. The error position estimation unit includes:
The terminal determined to have received a signal transmitted from the transmitter is classified into a first cluster, and the terminal determined to have received a signal transmitted from the other transmitter is defined as a second cluster. Classified into
Deriving the estimated position of the transmitter based on the estimated position of the terminal in the first cluster;
Deriving an estimated position of the other transmitter based on an estimated position of the terminal in the second cluster;
The position estimation apparatus according to claim 10 or 11, characterized in that   The position estimating device according to any one of claims 1 to 12, wherein the transmitter is a beacon. The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal Obtaining location time information and second location time information obtained at a second point at a second time after the reception time by the terminal;
From the first position time information and the second position time information, an average moving speed between the first point and the second point of the terminal is calculated,
Between the first time and the reception time when the average moving speed is not more than a predetermined value and the distance between the first point and the second point is not less than a predetermined distance At least one of the first time interval and the second time interval between the reception time and the second time, and the first time interval and the second time after the correction are corrected. Based on at least one of the time intervals, the position of the terminal at the reception time is estimated, and the position of the transmitter is estimated based on the estimation.
A position estimation program that causes a position estimation device to execute processing. The reception time when the terminal received the signal from the transmitter, the strength of the signal received by the terminal, and the first acquired at the first point at the first time before the reception time by the terminal Obtaining location time information and second location time information obtained at a second point at a second time after the reception time by the terminal;
From the first position time information and the second position time information, an average moving speed between the first point and the second point of the terminal is calculated,
Between the first time and the reception time when the average moving speed is not more than a predetermined value and the distance between the first point and the second point is not less than a predetermined distance At least one of the first time interval and the second time interval between the reception time and the second time, and the first time interval and the second time after the correction are corrected. Based on at least one of the time intervals, the position of the terminal at the reception time is estimated, and the position of the transmitter is estimated based on the estimation.
A position estimation method executed by the position estimation apparatus.