JP2019144120A - Indoor position estimation system, indoor position estimation method, and program for executing indoor position estimation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indoor position estimation system and an indoor position capable of deriving accurate position information of a mobile terminal from a radio wave intensity measured by a mobile terminal at an arbitrary position based on a predetermined indoor radio wave intensity distribution. A program for executing an estimation method and an indoor position estimation method is provided. SOLUTION: A radio wave intensity measuring means 20 for measuring a radio wave intensity of a radio wave transmitted from a transmitter 12 indoors 11, a data collecting means 21 for storing position information and a radio wave intensity of a plurality of measurement positions of the indoor 11 From the relationship between the position information of each measurement position and the radio wave intensity, the model building means 22 for obtaining the radio wave intensity distribution of the indoor 11 using the radiation basis function and the radio wave intensity measuring means 20 when the mobile terminal 13 is at an arbitrary position It has a position calculating means 23 for estimating the position of the mobile terminal 13 by deriving the position information of an arbitrary position from the measured radio wave intensity and the radio wave intensity distribution obtained in advance. [Selection diagram] Fig. 1

Description

The present invention relates to an indoor position estimation system that estimates the position of a mobile terminal that has received radio waves indoors, an indoor position estimation method, and a program that executes the indoor position estimation method.

In recent years, many location information services using a satellite navigation system (NSS) have been provided. However, since this system needs to receive radio waves from satellites, it cannot be used indoors where radio waves do not reach. Therefore, a technique for performing indoor position measurement (estimation) using received signal strength (RSSI: Received Signal Strength Indicator) in wireless communication such as Wi-Fi (registered trademark) or Bluetooth (registered trademark) has been proposed. Yes. This is done by installing a radio wave transmitter (radio wave light source) indoors and receiving the radio wave transmitted from this transmitter with a receiver (portable terminal) held by a person. ) Is specified. For example, Patent Document 1 obtains the distance between each of a plurality of base stations (transmitters) and a wireless mobile terminal based on the electric field strength (received signal strength) of a radio wave received by the mobile wireless terminal (receiver). A technique for forming a circle centered on the position of a base station and having a radius of a calculated distance for each of a plurality of base stations and estimating an intersection of the plurality of circles as the position of a wireless mobile terminal is disclosed. . In Patent Document 2, for each divided area obtained by dividing the detection area, the received radio wave intensity (received signal intensity) received by the receiver is measured in advance according to a plurality of states that the receiver can take, and radio wave information is obtained. The received radio wave intensity with the highest similarity is selected from the radio wave information compared to the received radio wave intensity received in a predetermined state by a receiver located in a certain divided area, and corresponding to it. A position specifying method for specifying a divided area as an area where a receiver is located is disclosed.

International Publication No. 97/33386 JP 2017-20240 A

However, since the radio wave is absorbed by the human body, even if the person with the receiver is standing at the same position, the signal strength received depending on the direction of the person's body and the way the receiver is held (angle and direction) May cause a difference in the distance between the transmitter and the receiver estimated from the difference. Therefore, as disclosed in Patent Document 1, based on the relationship between the electric field strength (signal strength) obtained using a wireless mobile terminal (receiver) and the distance in advance, the wireless strength is obtained from the electrolytic strength obtained by a certain wireless mobile terminal. In the method of estimating the position of the mobile terminal, there is a possibility that an accurate position cannot be estimated. Also, if there is an obstacle between the transmitter and the receiver, the radio wave is weakened by the obstacle, and the measured received signal strength is reduced, so the transmitter and receiver estimated from the received signal strength The distance to the aircraft will be longer than it actually is, and it may not be possible to estimate the exact position. In particular, an estimation error is likely to increase because obstacles such as furniture, desks, and shelves are installed in indoor spaces such as homes and offices. On the other hand, in Patent Document 2, since the received radio wave intensity (received signal intensity) is measured in advance in a plurality of states that the receiver can take, reception caused by differences in the direction of the person's body and how the receiver is held The measurement error of the radio field intensity can be reduced. In addition, instead of obtaining the relationship between the distance between the transmitter and the receiver and the received radio wave intensity, the area where the receiver is located is identified from the similarity of the received radio wave intensity, so transmission due to the influence of obstacles The estimation error of the distance between the receiver and the receiver can be eliminated. However, since the area where the received radio wave intensity is similar is specified as the area where the receiver is located, the accuracy of position determination depends on the size of the divided area (the number of detection areas). In other words, if the divided area is wide, the area where the receiver may exist is widened. Therefore, in order to achieve high-accuracy localization, the detection area must be divided finely. There is a problem that it takes time to measure the radio wave intensity and the amount of radio wave information to be stored increases. In addition, no matter how finely the detection area is divided, it is difficult to pinpoint the location of the receiver as long as the region with the highest similarity in received radio wave intensity is selected as the region where the receiver exists. Therefore, the accuracy of position estimation is limited.

The present invention has been made in view of such circumstances. A portable terminal (receiver) at an unknown position is obtained in advance by obtaining an indoor radio wave intensity distribution to be subjected to position estimation. ) Can be used to derive accurate location information of the mobile terminal, and it is possible to immediately respond to changes in the radio field intensity distribution due to indoor layout changes. An object is to provide an indoor position estimation system, an indoor position estimation method, and a program that executes the indoor position estimation method.

The indoor position estimation system according to the first aspect of the present invention is based on the radio field intensity when a portable terminal receives a radio wave transmitted from a transmitter installed indoors at an indoor position. An indoor position estimation system for estimating the position of the mobile terminal indoors,
A radio field intensity measuring means for measuring a radio field intensity when the portable terminal receives a radio wave transmitted from the transmitter indoors;
Data collection for storing the position information of each measurement position and the radio wave intensity at each measurement position when the radio wave intensity measurement means measures the radio wave intensity at a plurality of measurement positions where the indoor position information is known. Means,
From the relationship between the position information of each measurement position stored in the data collection means and the radio wave intensity at each measurement position, model building means for obtaining the indoor radio wave intensity distribution using a radiation basis function,
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the radio field intensity measured by the radio field intensity measuring unit and the radio field intensity distribution obtained in advance by the model construction unit And calculating position of the portable terminal by deriving position information of the arbitrary position.

Here, the transmitter and the portable terminal are not particularly limited, and may be any combination that allows the portable terminal to receive a radio wave (signal) transmitted by the transmitter, but a beacon device is preferable as the transmitter. As the mobile terminal, a wireless mobile terminal such as a smartphone or other personal digital assistant (PDA) is preferably used. In addition, the number of transmitters installed indoors is one or more, and 3 to 5 is preferable from the viewpoint of practicality, but it should be appropriately increased according to the indoor shape and size. (The same applies to the second and third inventions).

In the indoor position estimation system according to the first aspect of the invention, the data collection unit stores the radio field intensity measured by the radio field intensity measurement unit when the portable terminal is directed in a plurality of different directions at each measurement position. Is preferred.
Here, the direction of the mobile terminal at the time of measuring the radio field intensity at each measurement position can be selected as appropriate. However, when two or more transmitters are installed, the direction is adjusted to the direction of each transmitter. It is preferable. For example, when a transmitter is installed on each wall surface of a room formed in a rectangular or square shape in plan view, it is preferable to measure the radio field intensity with the receiver facing each wall surface (the second, and The same applies to the third invention).

The indoor position estimation system according to the first aspect of the invention preferably includes information providing means for displaying information on the position of the mobile terminal estimated by the position calculating means on a server accessible to a monitor.
Here, the number of supervisors can be selected as appropriate, and may be one or more. If you set up multiple monitors such as family (relatives), caregivers, doctors, nurses, etc. for monitoring subjects (users) such as children and elderly people who are carrying mobile terminals, The position information of the monitoring target person can be shared. The form of the server can be selected as appropriate. However, when a cloud server is used, the cost is low, the maintenance is not troublesome, and the handleability is excellent (the second and third inventions are described above). The same applies to the above).

In the indoor position estimation method according to the first invention, it is preferable that the transmitter is a beacon device and the portable terminal is a smartphone.
Here, as the beacon device, a device using Bluetooth Low Energy (BLE) excellent in power saving is preferably used, but is not particularly limited as long as the same radio wave (signal) can be transmitted (the foregoing, The same applies to the second and third inventions).

The indoor position estimation method according to the second invention according to the above object is based on the radio field intensity when a portable terminal receives a radio wave transmitted from a transmitter installed indoors at an indoor position. An indoor position estimation method for estimating the position of the mobile terminal indoors,
The radio signal transmitted from the transmitter is received by the portable terminal at a plurality of measurement positions where the indoor position information is known, the radio field intensity is measured by the radio field intensity measuring means, and the position information of each measurement position And a first step of storing the radio wave intensity at each measurement position in the data collection means,
A model construction unit obtains the indoor radio field intensity distribution using a radiation basis function from the relationship between the position information of each measurement position stored in the data collection unit and the radio field intensity at each measurement position. And the process of
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the portable terminal receives the radio wave transmitted from the transmitter, and the radio field intensity measuring means determines the radio field intensity at the arbitrary position. A third step of measuring;
The position calculating unit estimates the position of the mobile terminal by deriving position information of the arbitrary position from the radio field intensity at the arbitrary position and the radio field intensity distribution obtained in advance by the model construction unit. 4 steps.

In the indoor position estimation method according to the second aspect of the invention, in the first step, the radio field intensity measurement means measures the radio field intensity when the portable terminal is directed in a plurality of different directions at each measurement position, It is preferable to store in the data collecting means.

In the indoor position estimation method according to the second invention, it is preferable that the method includes a third step of displaying information on the position of the mobile terminal estimated by the position calculation unit on a server accessible to a monitor.

In the indoor position estimation method according to the second invention, it is preferable to use a beacon device as the transmitter and a smartphone as the portable terminal.

The program for executing the indoor position estimation method according to the third invention in accordance with the above object has a radio field intensity when a portable terminal receives a radio wave transmitted from a transmitter installed indoors at an arbitrary indoor position. A program for executing an indoor position estimation method for estimating the position of the mobile terminal in the indoor,
The mobile terminal receives radio waves transmitted from the transmitter at a plurality of measurement positions where the indoor position information is known, and the radio field intensity is measured by radio field intensity measuring means. The position information of each measurement position And a first step of storing the radio wave intensity at each measurement position in the data collection means;
A model construction unit obtains the indoor radio field intensity distribution using a radiation basis function from the relationship between the position information of each measurement position stored in the data collection unit and the radio field intensity at each measurement position. And the steps
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the portable terminal is caused to receive the radio wave transmitted from the transmitter, and the radio field intensity measuring means determines the radio field intensity at the arbitrary position. A third step of measuring;
The position calculating unit estimates the position of the mobile terminal by deriving position information of the arbitrary position from the radio field intensity at the arbitrary position and the radio field intensity distribution obtained in advance by the model construction unit. 4 is executed by the portable terminal.

In the program for executing the indoor position estimation method according to the third invention, in the first step, the radio wave intensity when the portable terminal is directed in different directions at the measurement positions by the radio wave intensity measuring means. Is preferably measured and stored in the data collection means.

In the program for executing the indoor position estimation method according to the third invention, the program includes a fifth step of displaying information on the position of the mobile terminal estimated by the position calculation unit on a server accessible to a monitor. It is preferable.

In the program for executing the indoor position estimation method according to the third invention, it is preferable that the transmitter is a beacon device and the mobile terminal is a smartphone.

In the indoor position estimation system according to the first aspect of the present invention, when the radio field intensity is measured by the radio field intensity measuring means at a plurality of measurement positions whose indoor position information is known, the position information of each measurement position and each measurement position are used. The data collection means for storing the radio field intensity, and the indoor radio field intensity distribution using the radiation basis function from the relationship between the position information of each measurement position stored in the data collection means and the radio field intensity at each measurement position By having the model construction means, it is possible to obtain the indoor radio wave intensity distribution in advance. Therefore, when actually estimating the position, simply measuring the radio wave intensity with the radio wave intensity measurement means, The position of the mobile terminal can be estimated easily and accurately over time, the processing time is short, the utility is excellent, and it can be used effectively for watching over children and the elderly. In particular, when the radio wave intensity distribution is obtained in the model building means, the radiation basis function is used, so that the measurement position is added or changed as necessary, and the position information and the radio wave intensity are collected to collect the indoor information. The radio wave intensity distribution can be updated to the latest information, and it is possible to respond immediately to layout changes, etc., and it has excellent functionality. In addition, it is necessary to measure the radio field intensity at each measurement position necessary for obtaining the indoor radio field intensity distribution by the model construction means, and to estimate the position of the mobile terminal at an arbitrary indoor position by the position calculation means. In the measurement of radio field strength at any arbitrary position, radio waves are received using the same mobile terminal and the radio field intensity is measured by the radio field strength measuring means, so variations in reception characteristics (such as antenna gain) for each mobile terminal The position estimation of the mobile terminal is excellent in reliability.

In the first invention, when the radio wave intensity measured by the radio wave intensity measuring means is stored in the data collecting means when the mobile terminal is directed in a plurality of different directions at each measurement position, the orientation of the mobile terminal is determined by the model construction means. The radio field intensity distribution can be obtained in consideration of the change in the radio field intensity due to the difference between the positions, and the accuracy of position estimation by the position calculating means can be improved.

1st invention WHEREIN: When the information regarding the position of the portable terminal estimated by the position calculation means is displayed on the server which a supervisor can access, a remote family (relative), a caregiver, a doctor, a nurse Can easily use the information to confirm the position of the person being monitored, such as a child or an elderly person who is carrying a portable terminal, which is particularly useful for assisting the lives of the elderly. be able to.

1st invention WHEREIN: When a transmitter is a beacon apparatus and a portable terminal is a smart phone, a system can be constructed | assembled at low cost and the spread can be aimed at.

The indoor position estimation method according to the second aspect of the invention receives radio waves transmitted from a transmitter at a plurality of measurement positions whose indoor position information is known, and measures the radio field intensity by radio field intensity measuring means. The first step of storing the position information of each measurement position and the radio wave intensity at each measurement position in the data collection means, and the position information of each measurement position stored in the data collection means by the model construction means and each measurement By having the second step of obtaining the indoor radio field intensity distribution using the radial basis function from the relationship with the radio field intensity at the position, the indoor radio field intensity distribution can be obtained in advance. When performing, the third step is to simply measure the radio field intensity with the radio field intensity measuring unit, and in the fourth step, the position calculating unit can easily and accurately estimate the position of the mobile terminal within a short time. To do Can, short processing time, excellent practicality, can be effectively used to like watching the children and the elderly. In particular, in the second step, when the radio wave intensity distribution is obtained by the model construction means, the measurement position is added or changed as necessary by using the radial basis function, and the position information and the radio wave intensity are added. It is possible to update the indoor radio field intensity distribution to the latest information, and to respond immediately to layout changes, etc., and it has excellent functionality. Further, in the first step and the third step, radio waves are received using the same portable terminal, and the radio field intensity is measured by the radio field intensity measuring means, so that reception characteristics (such as antenna gain) for each portable terminal are measured. The position estimation of the portable terminal is excellent in reliability.

In the second invention, in the first step, when the radio field intensity measurement means measures the radio field intensity when the portable terminal is directed in a plurality of different directions at each measurement position, and stores it in the data collection means, In step 2, the model construction means can obtain the radio field intensity distribution in consideration of the change in radio field intensity due to the difference in the orientation of the mobile terminal, and can improve the accuracy of position estimation in the fourth process. .

2nd invention WHEREIN: In the 4th process, when it has the 5th process which displays the information regarding the position of the portable terminal estimated by the position calculation means on the server which a supervisor can access, a remote family (Relatives), caregivers, doctors, nurses, and other monitors can easily use the information to confirm the position of the monitoring target person such as a child or an elderly person who is carrying a mobile terminal In particular, it can be used for life support of elderly people.

In the second invention, when a beacon device is used as a transmitter and a smartphone is used as a mobile terminal, indoor position estimation can be easily performed using an existing (commercially available) product.

A program for executing an indoor position estimation method according to a third aspect of the invention causes a portable terminal to receive radio waves transmitted from a transmitter at a plurality of measurement positions for which indoor position information is known, and the radio field intensity measurement means A first step of measuring radio wave intensity and storing the position information of each measurement position and the radio wave intensity at each measurement position in the data collection means, and the position of each measurement position stored in the data collection means by the model construction means Since there is a second step of obtaining the indoor radio field intensity distribution using the radiation basis function from the relationship between the information and the radio field intensity at each measurement position, the indoor radio field intensity distribution can be obtained in advance. When the position is estimated, the third step is to measure the radio field intensity only by the radio field intensity measuring unit. In the fourth step, the position calculating unit can Can estimate the end position easily and accurately, shorter processing time, excellent in practicability, it can be effectively utilized for such watch children and the elderly. In particular, when the radio wave intensity distribution is obtained in the second step, by using the radial basis function, the measurement position is added or changed as necessary, and the position information and the radio wave intensity are collected and collected indoors. The radio wave intensity distribution can be updated to the latest information, the layout can be changed immediately, and the functionality is excellent. In the first step and the third step, reception characteristics (for example, antenna gain, etc.) for each mobile terminal are received by receiving radio waves using the same mobile terminal and measuring the radio field intensity by the radio field intensity measuring means. ) And the reliability of position estimation of the mobile terminal is excellent.

In the third invention, in the first step, when the radio field intensity measurement means measures the radio field intensity when the receiver is pointed in a plurality of different directions at each measurement position and stores it in the data collection means, In step 2, the model construction means can determine the radio field intensity distribution in consideration of the change in radio field intensity due to the difference in the orientation of the mobile terminal, and can improve the accuracy of position estimation in the fourth step. .

3rd invention WHEREIN: When it has a 5th step which displays the information regarding the position of the portable terminal estimated by the position calculation means on the server which a monitor can access at a 4th step, it is a remote family (Relatives), caregivers, doctors, nurses, and other monitors can easily use the information to confirm the position of the monitoring target person such as a child or an elderly person who is carrying a mobile terminal In particular, it can be used for life support of elderly people.

In 3rd invention, when a transmitter is a beacon apparatus and a portable terminal is a smart phone, indoor position estimation can be easily performed using the existing (commercially available) product.

It is explanatory drawing of the indoor position estimation system which concerns on one embodiment of this invention. It is a top view which shows the indoor transmitter and measurement position used as the object of the position estimation by the same system. It is a block diagram which shows the structure of the system. It is a flowchart at the time of the offline operation | work of the program which performs the indoor position estimation method used with the system. It is a flowchart at the time of the online work of the program which performs the indoor position estimation method used with the system.

Subsequently, an embodiment in which the present invention is embodied will be described for the understanding of the present invention.
As shown in FIG. 1, an indoor position estimation system 10 according to an embodiment of the present invention generates radio waves (signals) emitted from a transmitter (for example, a beacon device) 12 installed in a target indoor (room) 11. The position of the mobile terminal 13 in the indoor 11 is estimated based on the radio wave intensity when the mobile terminal (for example, a wireless mobile terminal such as a smartphone) 13 receives the signal at an arbitrary position in the indoor 11. The indoor position estimation system 10 can be accessed via a network by a monitor 15 such as a family (relatives) of a monitoring target person (user) carrying a mobile terminal 13, a caregiver, a doctor, a nurse, or the like. A server (for example, a cloud server) 16 is connected. Thereby, the supervisor 15 can share the information regarding the position of the portable terminal (user) 13 via the server 16. Therefore, for example, by allowing the monitoring target person such as a child or an elderly person to carry the mobile terminal 13 and confirming its position, the remote monitoring person 15 can grasp the activity status of the monitoring target person. It can be used for watching services. Note that the number of the supervisors 15 may be one or a plurality of persons, and can be appropriately selected by the person to be monitored or the family of the person to be monitored. Moreover, privacy can also be protected by setting it as the structure which a monitoring subject can set whether the position estimation by the indoor position estimation system 10 is permitted.

First, as shown in FIG. 1 and FIG. 2, the transmitter 12 is installed in the indoor 11 at a position where wireless communication with the mobile terminal 13 can be performed using, for example, Bluetooth. It is configured to transmit radio waves. In the present embodiment, as shown in FIGS. 1 and 2, with respect to the indoor 11 formed in a square shape having a side of 10 m in plan view, the wall 17 has the same height at the center in the width direction. The transmitter 12 was installed, and a total of 49 measurement positions 18 (circles in FIG. 2) were set on the two-dimensional plane of the indoor 11 at seven locations in a vertical and horizontal direction. The size can be appropriately selected. The number and arrangement of the transmitters 12 and the measurement positions 18 can be appropriately selected according to the shape and size of the indoor 11. For example, the transmitter 12 does not necessarily have to be installed on all the walls 17 as long as the mobile terminal 13 can receive radio waves from the transmitter 12 at any position in the indoor 11. Only one may be installed in each. In addition, when the indoor 11 is wide, a plurality of transmitters 12 may be installed on one wall 17, or other than the wall 17, for example, may be installed on the ceiling. When installing the some transmitter 12 in the indoor 11, the height of each transmitter 12 does not need to be the same, You may install in a different height. Note that the measurement positions 18 need not be equally spaced, and may be partially sparse or dense depending on the positional relationship with various installations installed in the indoor 11. In addition, here, a case where wireless communication is performed using Bluetooth is described, but the present invention is not limited to this. For example, wireless LAN (for example, Wi-Fi), ZigBee (registered trademark), UWB, optical You may use radio | wireless communication systems, such as radio | wireless communication (for example, infrared rays).

Next, the portable terminal 13 can receive a radio wave (received signal) transmitted from each transmitter 12 (perform wireless communication with each transmitter 12) when present in the indoor 11. It has a configuration. Further, as the mobile terminal 13, a smartphone having a RAM, a CPU, a ROM, an I / O, and a bus (not shown) for connecting these elements, which are the same as those of a conventionally known arithmetic unit (that is, a computer), is preferable. However, other portable information terminals or the like having the same configuration may be used.
As shown in FIG. 3, the indoor position estimation system 10 includes a radio wave intensity measuring unit 20, a data collecting unit 21, a model building unit 22, a position calculating unit 23, and an information sharing unit 24. A program (application) for executing the indoor position estimation method used in the position estimation system 10 is installed in the portable terminal 13, and the CPU of the portable terminal 13 executes the program, whereby the portable terminal 13 is connected to the above-described radio wave intensity measuring means. 20, function as data collection means 21, model construction means 22, position calculation means 23, and information sharing means 24.

Hereinafter, an indoor position estimation method according to an embodiment of the present invention will be described based on the operation of each means.
First, as a preparatory work (offline work), after selecting (specifying) the indoor 11 that is the target of position estimation, at a plurality of measurement positions 18 shown in FIG. The mobile terminal 13 receives radio waves transmitted from each transmitter 12. Then, the radio field intensity is measured by the radio field intensity measuring means 20 shown in FIG. 3, and the position information of each measurement position 18 (in the present embodiment, coordinates in a two-dimensional space with the lower left corner of the indoor 11 as the origin) and The radio wave intensity (RSSI) at each measurement position 18 is stored in the data collection unit 21. The measurement position 18 only needs to have known position information, and the measurement of the radio wave intensity may be performed while sequentially moving the measurement position 18 set in advance, or may be appropriately selected on the spot. (The above is the first step).
Next, from the relationship between the position information of each measurement position 18 stored in the data collection means 21 and the radio wave intensity at each measurement position 18 by the model construction unit 22, the radio field intensity distribution in the room 11 using a radiation basis function. (The second step).
The preparation stage is completed as described above. If necessary, the measurement position can be added or changed. At the added or changed measurement position, the first step is performed to After updating the position information and radio wave intensity data, the radio wave intensity distribution in the indoor 11 can be updated to the latest information by performing the second step, and the layout change etc. can be handled immediately. Can do.

Next, at the stage where the position is actually estimated (online work), the mobile terminal 13 carried by the person being monitored is transmitted from each transmitter 12 when the position information of the indoor 11 is at an unknown arbitrary position. 3 is received by the portable terminal 13, and the radio field intensity measuring means 20 in FIG. 3 measures the radio field intensity at an arbitrary position (the third step).
Then, based on the radio wave intensity at the arbitrary position measured in the third step and the radio wave intensity distribution obtained in advance by the model construction unit in the second step, the position calculating unit 23 in FIG. Is derived to estimate the position of the mobile terminal 13 (the fourth step).
In the fourth step, information relating to the position of the mobile terminal 13 estimated by the position calculating means 23 is a server that can be accessed by a plurality of supervisors 15 by the information sharing means 24 of FIG. 3, as shown in FIG. 16 can be displayed (the fifth step).
Therefore, the monitoring person 15 using the indoor position estimation system 10, such as a family (relatives) of a monitoring target person (user), a caregiver, a doctor, a nurse, etc., uses the position information of the monitoring target person shared on the server 16. It can be easily confirmed, and it is possible to watch over a monitoring target person such as a child or an elderly person carrying the mobile terminal 13. Note that the position information data displayed on the server 16 by the information sharing means 24 can be stored in the server 16, confirming the movement history of the mobile terminal 13 (monitored person), analyzing the behavior pattern, and predicting the behavior. It can also be used as such data.

In the first step, the radio field intensity when the portable terminal 18 is directed in a plurality of different directions at each measurement position 18 by the radio field intensity measuring unit 20 and stored in the data collecting unit 21. The radio field intensity distribution can be obtained in consideration of the change in the radio field intensity due to the difference in direction of the mobile terminal 13, and the accuracy of position estimation in the fourth step can be improved.
Further, in performing the first step and the second step, a floor plan (plan view) of the indoor 11 is displayed on the display unit (screen) of the mobile terminal 13, and a table, bed, and sofa installed in the indoor 11 are displayed. , Furniture such as shelves, and other furniture, etc. can be displayed together. Thereby, a 1st process and a 2nd process can be performed in consideration of the position of an installation thing. In addition, in the fifth step, when the information regarding the position of the mobile terminal 13 is displayed on the server 16, if the position of the installation object is displayed together with the floor plan of the indoor 11, the supervisor 15 can monitor It is easy to grasp the behavior of the target person and is excellent in functionality and practicality. In addition, as a means (method) for displaying the position information of the installation object on the floor plan, the name of the installation object or the like may be input to the portable terminal 13 with characters or symbols, or the installation object registered in the list in advance. A name or the like may be selected on the screen of the mobile terminal 13.

Hereinafter, a program for executing an indoor position estimation method according to an embodiment of the present invention will be specifically described.
First, in the preparation stage work (offline work), as shown in FIG. 4, the indoor 11 to be subjected to position estimation is selected.
Next, at each measurement position 18 in the indoor 11, the mobile terminal 13 receives a radio wave transmitted from each transmitter 12 and measures the radio wave intensity by the radio wave intensity measuring means 20. The position information of 18 is stored in the matrix P, and the radio wave intensity at each measurement position 18 is stored in the matrix S. Since the signal (radio wave) received by the mobile terminal 13 includes noise, the measured radio wave intensity data is filtered and stored in the matrix S. For example, since the value (radio wave intensity) of the signal received by the mobile terminal 13 varies with time, noise can be reduced by performing processing such as averaging the values of a plurality of (for example, five) signals received at a predetermined interval. The accuracy of the position estimation can be improved by removing. When the measurement position 18 is M places (i = 1 to M), the above operation is repeated M times. The position information of each measurement position 18 thus obtained and the radio wave intensity at each measurement position 18 are stored in the data collection means 21 (the first step).
Since the position information (coordinates) of each measurement position 18 in the indoor 11 is a function of radio wave intensity (RSSI), it can be expressed as the following equation (1).

Here, P is a matrix representing the position information of each measurement position 18 in the indoor 11, S is a matrix representing the radio wave intensity at each measurement position 18 in the indoor 11, and C is the relationship between the position information and radio wave intensity in the indoor 11. This is a coefficient matrix.
In order to derive position information at an arbitrary position (unknown position) in the indoor 11 from the above relationship, a radial basis function (RBF) is applied. The radial basis function depends on the distance from the measurement position 18, and is interpolated between a plurality of measurement positions 18 whose position information is known, and at the time of position estimation, new position information is measured at an arbitrary position where the position information is unknown. The position information of an arbitrary position can be specified from the received radio wave intensity. Further, the radial basis function is characterized by a difference g in radio wave intensity at two measurement positions 18 and is expressed by the following equation (2).

Therefore, the model construction unit 22 normalizes the matrix S (stored in the data collection unit 21) obtained by measuring the radio field intensity in advance at the M measurement positions 18 in the indoor 11, and each measurement position 18 is normalized. Compute a matrix G describing the RBF representation of This matrix G is expressed by the following equation (3).

Here, s ⁱ and s ^j are the radio wave intensities at the i-th and j-th measurement positions 18, respectively, and this matrix G represents the radio wave intensity distribution in the indoor 11 (the second step).
Therefore, Formula (1) can be expressed as the following Formula (4).

Then, if the inverse matrix G (S) ^{−1 of the} matrix G (S) is obtained, the matrix C can be calculated by the following equation (5). This completes the preparation stage. The program according to the present embodiment can obtain and store the radio field intensity distribution in different indoors. And if necessary, as described above, it is possible to add or change the measurement position, collect the position information of the added or changed measurement position, and the radio wave intensity data, By redoing the above calculation, the radio field intensity distribution in the indoor 11 can be updated to the latest information.

Next, in the stage of actually performing position estimation (online work), as shown in FIG. 5, the indoor 11 that is the target of position estimation is selected.
Thereafter, the mobile terminal 13 carried by the monitoring subject receives radio waves transmitted from each transmitter 12 by the mobile terminal 13 in a state where the position information of the indoor 11 is unknown, The radio wave intensity at an arbitrary position is measured by the intensity measuring means 20. The measured radio wave intensity at an arbitrary position is stored in the matrix s. At this time, similarly to the first step, the measured radio wave intensity data is filtered and stored in the matrix s (the third step).
Next, the position calculation means 23 normalizes the matrix s obtained by measuring the radio wave intensity at an arbitrary position, and calculates a vector g for comparison with the previously obtained radio wave intensity distribution. This vector g represents the RBF effect of the radio wave intensity at an arbitrary position with respect to the radio wave intensity at each measurement position 18, and is expressed by the following equation (6).

Therefore, the position information p (s) at an arbitrary position can be expressed by the following equation (7).

Here, since the matrix C has already been obtained from the radio field intensity distribution in the room 11 by the equation (5), the position calculation means 23 substitutes the equation (5) into the equation (7), so that the position of the arbitrary position is obtained. Information can be derived and the position of the mobile terminal 13 can be estimated (the fourth step).
The information regarding the position of the mobile terminal 13 estimated in the fourth step can be displayed on the server 16 accessible by a plurality of supervisors 15 as shown in FIG. )
In the first step, the radio wave intensity measurement means 20 measures the radio wave intensity when the portable terminal 13 is directed in a plurality of different directions at each measurement position 18 and stores it in the data collection means 21. The radio field intensity distribution can be obtained in consideration of the change in the radio field intensity due to the difference in direction of the mobile terminal 13, and the accuracy of position estimation in the fourth step can be improved.
By executing a program for executing the indoor position estimation method according to the present embodiment on the mobile terminal 13, it is possible to estimate position information without using a computer separately. It can be provided at low cost.
The radial basis function (RBF) used for the interpolation of the radio wave intensity can be selected as appropriate. For example, the thin plate spline of Expression (8), the linear spline of Expression (9), and the three-dimensional expression of Expression (10) A function such as a spline or a multiple square of Equation (11) is preferably used. Here, c in Expression (11) is a tuning coefficient that is appropriately selected.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
In the above embodiment, when a program for executing the indoor position estimation method is installed in a portable terminal, the portable terminal functions as a radio wave intensity measuring unit, a data collecting unit, a model building unit, a position calculating unit, and an information sharing unit. However, for example, a computer that functions only as a radio wave intensity measuring unit and a data collecting unit and is connected to the portable terminal by wire or wirelessly so as to be able to communicate with the portable terminal is model building unit, position calculating unit, and information sharing unit. It can also function as. In that case, the portable terminal performs the first step and the third step, and transmits the acquired position information of each measurement position, radio wave intensity at each measurement position, and radio wave intensity data at an arbitrary position to the computer. Then, the second step, the fourth step, and the fifth step are performed on the computer side.

10: Indoor position estimation system, 11: Indoor, 12: Transmitter, 13: Portable terminal, 15: Monitor, 16: Server, 17: Wall, 18: Measurement position, 20: Radio wave intensity measuring means, 21: Data collection Means 22: model construction means 23: position calculation means 24: information sharing means

Claims (12)

An indoor position estimation system for estimating the position of the mobile terminal in the indoor based on the radio field intensity when the mobile terminal receives a radio wave transmitted from a transmitter installed indoors at the indoor arbitrary position. And
A radio field intensity measuring means for measuring a radio field intensity when the portable terminal receives a radio wave transmitted from the transmitter indoors;
Data collection for storing the position information of each measurement position and the radio wave intensity at each measurement position when the radio wave intensity measurement means measures the radio wave intensity at a plurality of measurement positions where the indoor position information is known. Means,
From the relationship between the position information of each measurement position stored in the data collection means and the radio wave intensity at each measurement position, model building means for obtaining the indoor radio wave intensity distribution using a radiation basis function,
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the radio field intensity measured by the radio field intensity measuring unit and the radio field intensity distribution obtained in advance by the model construction unit A position calculation means for estimating the position of the portable terminal by deriving position information of the arbitrary position from the indoor position estimation system. 2. The indoor position estimation system according to claim 1, wherein the data collection unit stores the radio field intensity measured by the radio field intensity measurement unit when the portable terminal is directed in a plurality of different directions at each measurement position. A featured indoor position estimation system. 3. The indoor position estimation system according to claim 1, further comprising information sharing means for displaying information on the position of the mobile terminal estimated by the position calculating means on a server accessible to a monitor. Indoor position estimation system. The indoor position estimation system according to any one of claims 1 to 3, wherein the transmitter is a beacon device, and the portable terminal is a smartphone. An indoor position estimation method for estimating a position of the mobile terminal in the indoor based on a radio wave intensity when the mobile terminal receives a radio wave transmitted from a transmitter installed indoors at the indoor arbitrary position. And
The radio signal transmitted from the transmitter is received by the portable terminal at a plurality of measurement positions where the indoor position information is known, the radio field intensity is measured by the radio field intensity measuring means, and the position information of each measurement position And a first step of storing the radio wave intensity at each measurement position in the data collection means,
A model construction unit obtains the indoor radio field intensity distribution using a radiation basis function from the relationship between the position information of each measurement position stored in the data collection unit and the radio field intensity at each measurement position. And the process of
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the portable terminal receives the radio wave transmitted from the transmitter, and the radio field intensity measuring means determines the radio field intensity at the arbitrary position. A third step of measuring;
The position calculating unit estimates the position of the mobile terminal by deriving position information of the arbitrary position from the radio field intensity at the arbitrary position and the radio field intensity distribution obtained in advance by the model construction unit. 4. An indoor position estimation method comprising: four steps. 6. The indoor position estimation method according to claim 5, wherein, in the first step, the radio field intensity measuring means measures radio field intensity when the portable terminal is directed in a plurality of different directions at each measurement position, An indoor position estimation method characterized by storing in a data collection means. 7. The indoor position estimating method according to claim 5, further comprising a fifth step of displaying information on the position of the mobile terminal estimated by the position calculating unit on a server accessible to a monitor. An indoor position estimation method. The indoor position estimation method according to any one of claims 5 to 7, wherein a beacon device is used as the transmitter and a smartphone is used as the portable terminal. An indoor position estimation method for estimating a position of the mobile terminal in the indoor based on a radio field intensity when the mobile terminal receives a radio wave transmitted from a transmitter installed indoors at the indoor arbitrary position A program to
The mobile terminal receives radio waves transmitted from the transmitter at a plurality of measurement positions where the indoor position information is known, and the radio field intensity is measured by radio field intensity measuring means. The position information of each measurement position And a first step of storing the radio wave intensity at each measurement position in the data collection means;
A model construction unit obtains the indoor radio field intensity distribution using a radiation basis function from the relationship between the position information of each measurement position stored in the data collection unit and the radio field intensity at each measurement position. And the steps
When the portable terminal is in an arbitrary position where the indoor position information is unknown, the portable terminal is caused to receive the radio wave transmitted from the transmitter, and the radio field intensity measuring means determines the radio field intensity at the arbitrary position. A third step of measuring;
The position calculating unit estimates the position of the mobile terminal by deriving position information of the arbitrary position from the radio field intensity at the arbitrary position and the radio field intensity distribution obtained in advance by the model construction unit. 4. A program for executing an indoor position estimation method characterized by causing the portable terminal to execute step 4. 10. The program for executing the indoor position estimation method according to claim 9, wherein in the first step, the radio field intensity measurement means calculates radio field intensity when the portable terminal is directed in a plurality of different directions at each measurement position. A program for executing an indoor position estimation method that measures and stores the data in the data collection means. The program for executing the indoor position estimation method according to claim 9 or 10, wherein a fifth step of displaying information on the position of the mobile terminal estimated by the position calculation means on a server accessible to a monitor. A program for executing an indoor position estimation method characterized by comprising: The program which performs the indoor position estimation method of any one of Claims 9-11 WHEREIN: The said transmitter is a beacon apparatus, The said portable terminal is a smart phone, The program which performs the indoor position estimation method characterized by the above-mentioned. .

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