JP2018031635A - Moving beacon location estimation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate a current location of a moving beacon.SOLUTION: A distance estimation part is configured to calculate one of three areas including an immediate area where the distance between a beacon and a reception terminal for distance estimation is the shortest, a near area where the distance between the beacon and the reception terminal for distance estimation is longer than that in the immediate area, and a far area where the distance between the beacon and the reception terminal for distance estimation is longer than that in the near area as an estimated distance, and change the range of each of the three areas according to the magnitude of a radio field intensity corresponding to each reference intensity signal when receiving a plurality of types of reference intensity signals from the beacon within a prescribed time. A location estimation part is configured to obtain a plurality of annular zones each of which expresses an area around a location indicated by each location information, being apart from each location by each estimated distance or an overlapping estimated area A-L which is an area where circles overlap with each other, and obtain an estimated location A-L-C from the overlapping estimated area.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a position estimation system for a moving beacon for estimating the position of a beacon that moves with a pedestrian and transmits radio waves, for example.

Conventionally, there is a desire to acquire information on the current position of a pedestrian (hereinafter referred to as “current position information”) in real time and to notify a person other than the pedestrian.
For example, there is a request that the parent of the child wants to know the current position information of the child who is a pedestrian in real time.

For example, wireless communication is possible between a portable terminal (for example, a smartphone) carried by a pedestrian and a data center, and between an information terminal (for example, a smartphone) owned by the pedestrian's family and the data center. In this case, the current position information of the pedestrian can be transmitted to the family information terminal.
That is, the mobile terminal of the pedestrian receives position information about itself from a satellite of the global positioning system (for example, GPS), and sends the received position information to the data center transmitting / receiving device together with the ID information of the mobile terminal. Wireless transmission. Further, the data center transmitting / receiving device wirelessly transmits the received position information as current position information to the family information terminal. At this time, if a map image based on the application installed on the family information terminal is displayed on the display of the information terminal, the current position of the pedestrian is displayed on the map image. Therefore, the child (pedestrian) family can know the current position information of the child in real time.

Japanese Patent Laying-Open No. 2015-224943

Mobile terminals such as smartphones are generally expensive.
On the other hand, a beacon that can transmit radio waves is cheaper than a portable terminal.
Therefore, if the pedestrian is given a beacon and the current position of the pedestrian can be specified (estimated) using the radio waves generated by this beacon, the economic burden on the pedestrian (and its family) will not be increased. The above request can be realized.

  However, until now there has been no means for estimating the current position of a moving beacon with a certain degree of accuracy.

  The present invention has been made to address the above-described problems. That is, one of the objects of the present invention is to provide a position estimation system for a moving beacon that can estimate the position of a beacon that moves together with a moving object with a certain degree of accuracy.

In order to achieve the above object, a mobile beacon position estimation system according to the present invention comprises:
A transmitter (24) that can move together with the mobile body (P1) and transmits a radio wave including a beacon ID signal that is identification information of itself and a reference intensity signal that represents the radio wave intensity, and the radio wave intensity is predetermined. A beacon (20) having an intensity adjustment unit (22) that changes at a period of
A terminal-side receiving unit (29) that receives the radio wave transmitted by the beacon together with the identification information and the reference intensity signal, and corresponds to the beacon ID signal based on the actual intensity of the received radio wave and the reference intensity signal A distance estimation unit (27) that calculates an estimated distance (L1, L2, L3) that is a distance between the beacon and itself, a terminal ID signal that is identification information of itself, its own location information, the beacon ID signal, and A plurality of distance estimation receiving terminals (25A) comprising a terminal-side transmitting section (29) for transmitting radio waves together with the estimated distance;
A radio wave receiver (16) that receives the terminal ID signal, the position information, the beacon ID signal, and the estimated distance transmitted by the plurality of distance estimation receiving terminals, and a plurality of the estimated distance and a plurality of the distances A position estimation device (15) comprising a position estimation unit (16) for obtaining an estimated position (ALC) that is the position of the beacon based on the position information;
With
The distance estimation unit is an immediate area where the distance between the beacon and the distance estimation receiving terminal is closest, a near area where the distance between the beacon and the distance estimation receiving terminal is farther than the immediate area, and the beacon and the When one of the three areas of the far area far from the near area is calculated as the estimated distance and a plurality of types of reference intensity signals are received from the beacon within a predetermined time In addition, each of the three regions is configured to change the range according to the magnitude of the radio wave intensity corresponding to each reference intensity signal,
The position estimation unit (16) has a plurality of annular bands or circles (C1, C2, C3) each representing a region centered on the position represented by the position information and separated from the position by the estimated distance. An overlap estimation area (AL) that is an overlapping area is obtained, and the estimated position is obtained from the overlap estimation area (step 1402).

For example, pedestrians, bicycles, automobiles, and the like can be moving objects.
For example, a smartphone, a tablet computer, and a notebook personal computer can be used as a distance estimation receiving terminal.

Theoretically, as the number of types of annular bands or circles used when obtaining the overlap estimation area increases, the overlap estimation area does not include a distance greatly deviating from the actual beacon position. In other words, the error between the estimated position obtained from the overlap estimation area and the actual position of the moving object is reduced.
In the present invention, by setting the “predetermined time” to a short time, a plurality of types of annular bands or circles are configured based on a plurality of types of radio waves having different radio field strengths transmitted from beacons at substantially the same time. To do. Then, the position estimation unit obtains an overlap estimation area which is an area where these annular bands or circles overlap each other, and obtains an estimated position from the overlap estimation area.

In this overlap estimation area, an area representing a distance greatly deviating from the actual beacon position is largely excluded as compared with each annular band or circle. In other words, the overlap estimation area more accurately represents the actual current position of the beacon than each annular band or circle.
Therefore, the estimated position of the beacon obtained by the position estimation unit is highly likely to represent the current position of the beacon at a certain height. That is, there is a high possibility that the error between the obtained estimated position and the actual current position of the beacon is small.

  In one aspect of the present invention, the standard of the radio wave transmitted by the transmission unit (24) of the beacon is Bluetooth Low Energy.

  If the present invention is implemented in this manner, the power consumption per unit time of the beacon can be reduced.

  In one aspect of the present invention, the position estimation unit (16) obtains the estimated position based on map data representing an area where the beacon and the plurality of distance estimation receiving terminals are located, and the overlap estimation area. It is configured.

For example, when the moving body is a pedestrian, the possibility that the moving body is in a river in the map data is low. For this reason, in this case, there is a high possibility that the moving body is located in a region where a portion overlapping the river is excluded from the overlap estimation region.
Therefore, for example, if an estimated position is obtained from the remaining area by excluding a portion where the moving object is unlikely to be located from the overlap estimated area by such a method, the obtained estimated position and the actual current position of the moving object are obtained. And the error can be made smaller.

  1 aspect of this invention WHEREIN: The said position estimation apparatus has an electromagnetic wave transmission part (16) which transmits the information regarding the said estimated position with respect to the receiving terminal (25B) separate from the said receiving terminal for distance estimation.

  If the present invention is implemented in this manner, it becomes possible to notify the estimated position of the beacon to the receiving terminal separate from the distance estimating receiving terminal.

  In the above description, in order to help understanding of the present invention, names and / or symbols used in the embodiment are attached to the configuration of the invention corresponding to the embodiment described later in parentheses. However, each component of the present invention is not limited to the embodiment defined by the reference numerals. Other objects, other features and attendant advantages of the present invention will be readily understood from the description of the embodiments of the present invention described with reference to the following drawings.

It is a figure which shows the position estimation system of the movement beacon which concerns on embodiment of this invention. It is a figure which shows the object pedestrian who possesses a beacon. It is a figure which shows the pedestrian who has a smart phone. It is a figure which shows the family F (target pedestrian P1) who possesses a smart phone. . It is a figure which shows the display of a data center. The figure which shows the principle which the information processing apparatus of a data center estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which two smart phones calculated based on the radio signal which the beacon transmitted in the first intensity switching cycle. It is. It is a figure which shows the principle which information processing apparatus estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which three smart phones calculated based on the radio signal which the beacon transmitted in the 1st intensity | strength switching period. It is a figure which shows the principle which information processing apparatus estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which two smart phones calculated based on the radio signal which the beacon transmitted in the 2nd intensity | strength switching period. It is a figure which shows the principle which information processing apparatus estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which three smart phones calculated based on the radio signal which the beacon transmitted in the 2nd intensity | strength switching period. It is a figure which shows the principle which information processing apparatus estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which two smart phones calculated based on the radio signal which the beacon transmitted in the 3rd intensity | strength switching period. It is a figure which shows the principle which information processing apparatus estimates the position of a beacon based on the estimated distance from each smart phone to a beacon which three smart phones calculated based on the radio signal which the beacon transmitted in the 3rd intensity | strength switching period. It is a flowchart which shows the process which the IC chip of a beacon performs. It is a flowchart which shows the process which ECU of the smart phone which a pedestrian has performs. It is a flowchart which shows the process which information processing apparatus performs. It is a flowchart which shows the process which ECU of the smart phone which a family possesses performs.

A mobile beacon position estimation system 10 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, the position estimation system 10 of the present embodiment includes a data center 15, a beacon 20, and smartphones 25A and 25B as main components.

  The data center 15 includes an information processing device 16 (computer server) and a display 18.

As shown in FIG. 1, the information processing device 16 in the data center 15 performs data communication with the smartphones 25A and 25B via the network.
This network includes a communication network of a communication carrier and an Internet network.
The smartphones 25A and 25B perform wireless communication (data communication) with the base station of the communication carrier. This base station is connected to the Internet network via the communication network of the communication carrier.
The information processing device 16 performs data communication with the Internet network.
Furthermore, as will be described later, the smartphone 25A can receive radio waves transmitted by the beacon 20.

  The information processing device 16 installed in the building of the data center 15 is an electronic control circuit having a microcomputer including a CPU, a ROM, a RAM, an interface, and the like as main components. The CPU implements various functions to be described later by executing instructions stored in a memory (ROM). In this memory, map data and various software described later are recorded. As is well known, the CPU executes each operation described later by executing instructions of each software.

A dynamic map DM shown in FIG. 5 is displayed on the display 18 connected to the information processing apparatus 16. The dynamic map DM is composed of a plurality of layers (layers) overlapped with each other. The degree of change according to the time change of the information represented by each layer is different for each layer.
The layer with the smallest change (substantially does not change) according to the time change is a map image based on the map data. The other layers represent information that changes with time. For example, one layer different from the map image represents the position information of the beacon 20 and the smartphones 25A and 25B.

This map image represents a specific area around the data center 15.
The map image includes images of two roads R1 and R2 that are parallel to each other. Furthermore, the map image includes roads R3, R4, R5, and R6 orthogonal to the roads R1 and R2. All of these roads R1, R2, R3, R4, R5, R6 (including bicycles and motorcycles) can be passed by vehicles and pedestrians.
The roads R1 and R3 are divided into a left lane and a right lane by a center separation line drawn with a one-dot chain line. The vehicle passes through the left lane of the roads R1 and R3. There is no central separation line on the roads R2, R4, R5, and R6.
Road R5 is a bridge. A river LV parallel to the roads R1 and R2 flows below the road R5.
Further, the map image includes images of a plurality of buildings (houses, buildings, factories, etc.) BL.

In addition, this map image is comprised by many grids (grid-like minimum unit). The length of each side of this grid is a distance corresponding to 2 m of actual geography.
Accordingly, when the current position of the beacon 20 (estimated position ALC) and the current position of the smartphones 25A and 25B on the map image are obtained as described later, these current positions are positions corresponding to one grid. .

  Further, the display 18 displays a map image so that the current position of the beacon 20 is included. That is, when the beacon 20 (target pedestrian P1) moves, the display 18 displays the map image while scrolling.

The beacon 20 is a small and lightweight tag.
An IC chip 22, a battery 23, and an antenna 24 are provided inside a case 21 that forms the outer shape of the beacon 20.

  The IC chip 22 is a small electronic component having a single substrate and a large number of electronic components (for example, transistors, resistors, capacitors, and diodes) mounted on the substrate. The IC chip 22 has a function of generating a radio signal (radio wave). The standard of radio waves generated by the IC chip 22 is Bluetooth Low Energy. That is, the IC chip 22 generates a 2.4 GHz band radio wave. The IC chip 22 generates a radio signal every predetermined time (for example, every 100 milliseconds). Furthermore, every time the IC chip 22 generates a radio signal, the IC chip 22 generates a beacon ID signal for identifying the beacon 20 from other beacons.

  The battery 23 is a button type battery. The battery 23 always supplies power to the IC chip 22 and the antenna 24 until the capacity becomes zero. Since the standard of the radio wave generated by the IC chip 22 is Bluetooth Low Energy, the power consumption per unit time of the battery 23 is small.

  The antenna 24 is connected to the IC chip 22. When the IC chip 22 supplied with power from the battery 23 generates a radio signal, the antenna 24 repeatedly transmits the generated radio signal to the outside together with the beacon ID signal every predetermined time (for example, every 100 milliseconds). To do. Hereinafter, the transmission cycle of the radio signal by the beacon 20 is referred to as a “beacon transmission cycle”.

  Furthermore, the IC chip 22 changes the intensity of the radio wave generated by itself every predetermined time (for example, every second). There are three types of radio wave intensities that can be generated by the IC chip 22: Type 1, Type 2, and Type 3. Type 2 has higher radio field intensity (unit: dB) than Type 1, and Type 3 has higher radio field intensity than Type 2. Hereinafter, the radio wave intensity switching cycle by the IC chip 22 is referred to as an “intensity switching cycle”.

  Further, when the IC chip 22 generates radio waves (that is, every 100 milliseconds, for example), the IC chip 22 generates a reference intensity signal indicating the magnitude of each type of radio wave intensity. The radio wave intensity (reference intensity) represented by the reference intensity signal is the radio wave received by the receiver when the receiver (for example, a smartphone) receives the radio wave transmitted by the antenna 24 at a position 1 m away from the beacon 20. Represents radio field intensity. That is, the reference intensity corresponding to type 2 is higher than the reference intensity corresponding to type 1. Similarly, the reference intensity corresponding to type 3 is higher than the reference intensity corresponding to type 2.

Each reference intensity signal and beacon ID signal generated by the IC chip 22 are superimposed on the radio signal generated by the IC chip 22 as one set. One set having a reference strength signal and a beacon ID signal can be superimposed on a radio signal as a payload, for example.
The antenna 24 transmits a type 1 radio wave together with a beacon ID signal and a reference intensity signal corresponding to the type 1. Similarly, the antenna 24 transmits type 2 radio waves together with a beacon ID signal and a reference intensity signal corresponding to type 2. Similarly, the antenna 24 transmits type 3 radio waves together with a beacon ID signal and a reference intensity signal corresponding to type 3.

  If the IC chip 22 incorporated in the beacon 20 is replaced with another type of IC chip (not shown), the beacon 20 can generate a plurality of types of radio waves (and reference intensity signals) having different strengths from the above. . In this case, the number of types of radio waves generated by the beacon 20 may be three, or a plurality of types other than three may be used. Furthermore, the beacon transmission cycle and the intensity switching cycle can be changed by exchanging another type of IC chip.

In the present embodiment, the target pedestrian P1 shown in FIGS. 2 and 5 has the beacon 20. More specifically, the target pedestrian P1 who is a child (for example, an elementary school student) wears a bag P1a, and the beacon 20 is attached to the bag P1a.
Information such as the name, age, and address of the target pedestrian P1 is recorded in association with the beacon ID signal in the information processing device 16 of the data center 15 and the ROM of the smartphone 25B.

The basic structures of the smartphone 25A and the smartphone 25B are the same.
An ECU 27, a battery 28, a radio communication antenna 29, and a GPS reception antenna 30 are provided inside a case 26 that forms the outer shape of the smartphones 25A and 25B.

  The ECU 27 (electric control unit) is an electronic control circuit having a microcomputer including a CPU, a ROM, a RAM, an interface, and the like as main components. The CPU implements various functions to be described later by executing instructions stored in a memory (ROM). Further, various software (applications) are installed in the memory of the ECU 27. For example, a predetermined “pedestrian position display application” is installed in the memory of the smartphone 25B.

The ECU 27 can generate a radio signal.
Furthermore, the ECU 27 can repeatedly generate a terminal ID signal for identifying each smartphone 25A, 25B from other smartphones at predetermined time intervals (for example, every second).
Further, the ECU 27 records the generated terminal ID signal in the RAM in time series.

  The battery 28 is a rechargeable battery, and always supplies power to the ECU 27, the radio communication antenna 29, the GPS reception antenna 30, and the display 31 until the capacity becomes zero.

The wireless communication antenna 29 is connected to the ECU 27. When the smartphones 25 </ b> A and 25 </ b> B are located within the range where the radio signal transmitted by the beacon 20 reaches, the wireless communication antenna 29 receives the radio signal, the beacon ID signal, and the reference strength signal transmitted by the beacon 20 every predetermined time (for example, Repeatedly every 100 milliseconds). Hereinafter, the reception cycle of the radio signal, the beacon ID signal, and the reference strength signal transmitted from the beacon 20 by the radio communication antenna 29 is referred to as a “beacon transmission information reception cycle”. This beacon transmission information reception cycle can be the same as the beacon transmission cycle, for example.
Further, the ECU 27 records the received beacon ID signal and reference intensity signal in the RAM in time series.

The GPS receiving antenna 30 is connected to the ECU 27. As is well known, the GPS receiving antenna 30 receives a GPS signal transmitted from a GPS satellite, whereby information on the position of the GPS receiving antenna 30 (smartphones 25A and 25B) (hereinafter referred to as “GPS position information”). ) Repeatedly at predetermined time intervals (for example, every second). Hereinafter, the reception cycle of the GPS position information by the GPS receiving antenna 30 is referred to as “GPS information reception cycle”. For example, the GPS information reception cycle can be the same as the intensity switching cycle.
Further, the ECU 27 records the received GPS position information in the RAM in time series, for example, at the same cycle as the GPS information reception cycle.

Further, as will be described later, the radio communication antenna 29 repeats the beacon ID signal, the GPS position information, the terminal ID signal, and the like recorded in the RAM repeatedly according to a command from the ECU 27, for example, at the same period as the GPS information reception period. Wireless transmission.
Furthermore, the radio communication antenna 29 can receive a radio signal transmitted from the base station.

Further, a display 31 is provided on the surface of the case 26. This display 31 is also connected to the ECU 27.
Furthermore, input means (not shown) connected to the ECU 27 is provided on the surfaces of the smartphones 25A and 25B. The format of this input means does not matter. That is, the input unit may be, for example, a mechanical button that can be moved relative to the case 26, or may be a touch panel that forms part of the display 31.

In the present embodiment, the smartphone 25A is possessed by a plurality of pedestrians P2 shown in FIGS.
Furthermore, as shown in FIG. 4, the smartphone 25B is possessed by the family F (one person) of the target pedestrian P1.

Next, an outline of the operation of the position estimation system 10 will be described. In the following description, it is assumed that the following states 1 to 4 are realized.
State 1: The capacities of the battery 23 of the beacon 20 and the batteries 28 of the smartphones 25A and 25B are not zero.
State 2: The power switches of the smartphones 25A and 25B are in the ON state.
State 3: The ECU 27 of the smartphone 25B reads the pedestrian position display application (in other words, the map image of the pedestrian position display application is displayed on the display 31 of the smartphone 25B).
State 4: A plurality of pedestrians P2 are located in a circle (predetermined area) with a predetermined radius centered on the beacon 20.

  In the present embodiment, the intensity of the radio signal transmitted by the beacon 20 possessed by the target pedestrian P1 is changed at a predetermined intensity switching period (for example, 1 second). However, regardless of the strength of the radio signal, the radio signal transmitted from the beacon 20 reaches several tens of meters from the beacon 20. In other words, when the smartphone 25A (pedestrian P2) is located inside a circle with a radius of several tens of meters centered on the beacon 20, a wireless signal transmitted by the beacon 20 is received by the smartphone 25A.

  When the wireless communication antenna 29 of the smartphone 25A receives the wireless signal transmitted by the beacon 20, the beacon ID signal, and the reference strength signal, the ECU 27 actually receives the strength of the received wireless signal (hereinafter referred to as “actual strength”) and The reference intensity represented by the reference intensity signal is compared. Then, the ECU 27 calculates (estimates) an estimated distance that is a distance between the smartphone 25A and the beacon 20 based on the actual intensity and the reference intensity.

Specifically, the ECU 27 calculates the estimated distance as follows.
For example, when the actual intensity is significantly larger than the reference intensity, the ECU 27 estimates that “the estimated distance is in the immediate area”. This immediate area is an area where the distance between the beacon 20 and the smartphone 25A is extremely close.
When the actual intensity is slightly larger than the reference intensity, the ECU 27 estimates that “the estimated distance is in the near region”. This near area is an area where the distance between the beacon 20 and the smartphone 25A is short and far from the immediate area.
When the actual intensity is smaller than the reference intensity, the ECU 27 estimates that “the estimated distance is in the far region”. This far area is an area where the distance between the beacon 20 and the smartphone 25A is farther than the near area.
However, the magnitude relationship between the actual intensity and the reference intensity and the relation between the three estimated distances are not limited to this relation.

The ranges of the immediately area, the near area, and the far area vary depending on the magnitude of the reference intensity represented by the reference intensity signal received by the smartphone 25A. That is, the immediate area, near area, and far area of each radio wave intensity (type 1, type 2, and type 3) generated by the IC chip 22 have the following sizes.

(Type 1)
immediately area: 1m or less
Near area: greater than 1m and less than 3m
Far area: greater than 3m and less than 10m (Type 2)
immediately area: 2m or less
Near area: greater than 2m and less than 5m
Far area: greater than 5m and less than 15m (Type 3)
immediately area: 2.5m or less
Near area: greater than 2.5m and less than 8m
Far area: greater than 8m and less than 20m

  When the ECU 27 of the smartphone 25A repeatedly calculates the estimated distance every predetermined time (for example, every 100 milliseconds), the ECU 27 calculates the calculated estimated distance together with the reference intensity signal and the beacon ID signal every predetermined time (for example, 100 milliseconds). Every time) in the RAM in time series.

By the way, as described above, the ECU 27 records the received GPS position information in the RAM in time series in the same cycle as the GPS information reception cycle.
When the ECU 27 records one GPS position information in the RAM, the estimated distance calculated by the ECU 27 during the GPS information reception period when the GPS position information is received by the GPS receiving antenna 30, and wireless communication The beacon ID signal and the reference intensity signal received by the antenna 29 are recorded in the RAM as a set with this GPS position information. As described above, the GPS information reception cycle is longer than the beacon transmission information reception cycle, and a plurality of beacon transmission information reception cycles elapse while one GPS information reception cycle elapses. Therefore, one GPS position information, a plurality of estimated distances, a plurality of reference intensity signals, and a plurality of beacon ID signals are recorded in the RAM as one set. For example, when the GPS information reception cycle is 1 second and the beacon transmission information reception cycle is 100 milliseconds, one GPS position information, 10 estimated distances, 10 reference strength signals, and 10 beacon IDs Signals are recorded in RAM as a set. Hereinafter, this one set is referred to as “estimated distance and GPS information set”.

  Further, the radio communication antenna 29 is based on a command from the ECU 27, and includes GPS position information (or estimated distance and GPS information set) and a terminal ID signal as a set to the information processing device 16 in the data center 15. For example, it repeatedly transmits at a predetermined cycle (for example, 1 second) that is the same as the GPS information reception cycle.

The information processing device 16 receives, for example, GPS position information (or estimated distance and GPS information set) and a terminal ID signal from a plurality of smartphones 25 for each center reception cycle having the same length as the GPS information reception cycle, and The GPS position information (or estimated distance and GPS information set) and the terminal ID signal are recorded in the RAM at a predetermined cycle (for example, the same cycle as the center reception cycle).
When the estimated distance and the GPS information set are received from each smartphone 25, the information processing apparatus 16 determines the current position of the beacon 20 (target pedestrian P1) corresponding to the received beacon ID signal based on the information regarding the plurality of estimated distances. The estimation is based on the following principle.

For example, when the estimated distance and the GPS information set are received together with the corresponding terminal ID signal from only the two smartphones 25A (25A-1 and 25A-2) in one center reception cycle, the information processing device 16 is shown in FIG. Based on the principle shown in Fig. 4, a range that is estimated to include the current position of the beacon 20 (target pedestrian P1) is obtained.
That is, the information processing apparatus 16 includes the annular band C1 centered on the smartphone 25A-1 and having the upper limit value of the estimated distance L1 (far region) calculated by the smartphone 25A-1 as the outer diameter and the lower limit value as the inner diameter, and the smartphone. A temporary estimated area A-2 is obtained in which the upper limit value of the estimated distance L2 (far area) calculated by the smartphone 25A-2 is the outer diameter and the annular band C2 having the lower limit value is the inner diameter. . This temporary estimation area A-2 is a range in which the current position of the beacon 20 is estimated to be included. For example, when the estimated distance L1 is an immediate area, the area where the circle C1 having the radius of the upper limit of the estimated distance L1 and the annular band C2 overlaps is the temporary estimated area A-2.

Note that one estimated distance and GPS information set received by the information processing apparatus 16 from each of the smartphones 25A-1 and 25A-2 usually includes a plurality of estimated distances. Therefore, when the information processing apparatus 16 receives one estimated distance and GPS information set from each of the smartphones 25A-1 and 25A-2, it usually calculates four or more temporary estimated areas A-2.
These temporary estimation areas A-2 are calculated based on a radio signal having the same radio wave intensity transmitted from the beacon 20. Therefore, the shapes of these temporary estimation areas A-2 are almost the same.

Further, when the estimated distance and the GPS information set are received together with the corresponding terminal ID signal from the three smartphones 25 (25A-1, 25A-2, 25A-3) in one center reception cycle, the information processing device 16 Obtains a range estimated to include the current position of the beacon 20 based on the principle shown in FIG.
In other words, the information processing device 16 uses the annular band C1, the annular band C2, and the smartphone 25A-3 as the center, the upper limit value of the estimated distance L3 calculated by the smartphone 25A-3 as the outer diameter, and the lower limit value as the inner diameter. A temporary estimation area A-3 overlapping with the annular band C3 (near area) is obtained. This temporary estimation area A-3 is a range in which the current position of the beacon 20 is estimated to be included.
Since the temporary estimation area A-3 is an area based on three estimated distances, there is a high possibility that the current position of the beacon 20 is more accurately represented than the temporary estimation area A-2.
Also in this case, since the normal information processing device 16 receives a plurality of estimated distances from the three smartphones 25A for each center reception cycle, the information processing device 16 normally has six or more temporary estimation regions A− for each center reception cycle. 3 is determined.

When the information processing device 16 receives the estimated distance and the GPS information set together with the corresponding terminal ID signal from four or more smartphones 25A in one center reception cycle, the information processing device 16 has four smartphones 25A. Areas corresponding to the temporary estimation areas A-2 and A-3 are obtained based on the estimated distance and the GPS information set received from.
As the number of smartphones 25 that transmit the estimated distance and the GPS information set to the information processing device 16 increases, the information processing device 16 more accurately obtains a range estimated to include the current position of the beacon 20. It becomes possible.

By the way, as described above, the beacon 20 repeatedly transmits radio waves while changing the radio wave intensity every intensity switching period. Therefore, when one intensity switching period (hereinafter referred to as “first intensity switching period”) ends and the next intensity switching period (hereinafter referred to as “second intensity switching period”) arrives, each beacon 20 Change the signal strength. That is, the beacon 20 switches the radio field intensity from type 1 to type 2, type 2 to type 3, or type 3 to type 1.
Therefore, when the information processing device 16 receives the estimated distance obtained by each smartphone 25A based on the wireless signal transmitted by the beacon 20 and the reference strength signal in the second strength switching period, as shown in FIGS. The processing device 16 calculates a plurality of temporary estimation areas A-2 ′ and A-3 ′.

Then, the estimated distance (that is, the shape of the annular band, circles C1, C2, and C3) obtained by each smartphone 25A based on the wireless signal transmitted by the beacon 20 and the reference intensity signal in the second intensity switching period is the first intensity switching. This is different from the estimated distance obtained by each smartphone 25A based on the radio signal transmitted by the beacon 20 and the reference intensity signal in the cycle.
Therefore, there is a high possibility that the shapes of the temporary estimation areas A-2 ′ and A-3 ′ are different from the temporary estimation areas A-2 and A-3.

  Further, the estimated distance obtained by each smartphone 25A based on the radio signal and the reference intensity signal transmitted by the beacon 20 in the intensity switching period (hereinafter referred to as “third intensity switching period”) following the second intensity switching period is information. When the processing device 16 receives the information, the information processing device 16 calculates a plurality of temporary estimation regions A-2 ″ and A-3 ″ as illustrated in FIGS. 10 and 11.

Then, the estimated distance (that is, the shape of the annular band, circles C1, C2, and C3) obtained by each smartphone 25A based on the wireless signal transmitted by the beacon 20 and the reference intensity signal in the third intensity switching period is the second intensity switching. This is different from the estimated distance obtained by each smartphone 25A based on the radio signal transmitted by the beacon 20 and the reference intensity signal in the cycle.
Therefore, there is a high possibility that the shapes of the temporary estimation areas A-2 ″ and A-3 ″ are different from the temporary estimation areas A-2 ′ and A-3 ′.

  Then, the information processing device 16 uses the wireless signal and the reference intensity signal transmitted from the beacon 20 in the continuous first intensity switching period, second intensity switching period, and third intensity switching period to obtain a temporary estimation area A-2. (A-3), A-2 ′ (A-3 ′), and A-2 ″ (A-3 ″) are overlapped with each other to calculate the overlap estimation region AL. The overlap estimation area A-L is an area indicated by a two-dot chain line in FIG.

  It is estimated that the distance that the target pedestrian P1 carrying the beacon 20 and the pedestrian P2 carrying the smartphone 25A can move during the first intensity switching period, the second intensity switching period, and the third intensity switching period is very small. The In other words, it is estimated that the distance that the target pedestrian P1 and the pedestrian P2 can move during this time is equal to or less than the actual distance (2 m) corresponding to each side of one grid. Accordingly, each of the temporary estimation areas A-2 (A-3), A-2 ′ (A-3 ′), and A-2 ″ (A-3 ″) is the target at substantially the same time. It can be said that it represents an area where the pedestrian P1 may be located. In other words, each radio signal transmitted by the beacon 20 in the first intensity switching period, the second intensity switching period, and the third intensity switching period can be treated as being transmitted by the beacon 20 at substantially the same time. .

When the moving speed of the target pedestrian P1 and / or pedestrian P2 is fast, the target pedestrian P1 and / or walking during the continuous first intensity switching period, second intensity switching period, and third intensity switching period. The person P2 may move a distance longer than 2 m.
However, as long as the moving distance is not significantly longer than 2 m, each radio signal transmitted by the beacon 20 in the first intensity switching period, the second intensity switching period, and the third intensity switching period is substantially equal to the beacon at the same time. 20 can be treated as a transmission.

Furthermore, when at least one of the estimated distances transmitted from each smartphone 25A to the information processing device 16 is a “near region” or a “far region”, the overlap estimation region A-L is a large region. In particular, when any of the estimated distances is a “far region”, the overlap estimation region AL may be a very large region. In other words, in these cases, the overlap estimation area A-L is likely to represent a (substantially) wider area than one grid. Therefore, in these cases, it is inappropriate to treat the overlap estimation area A-L as the current position of the beacon 20 (target pedestrian P1).
Therefore, the information processing device 16 performs the following filtering process on the obtained overlap estimation area A-L.

The overlap estimation area A-L shown in FIG. 5 overlaps a part of the river LV and a part of the building BL.
However, it is considered that the possibility that the target pedestrian P1 is in the river LV is low. Furthermore, it is considered that the possibility that the target pedestrian P1 is in the building BL having an address different from the address of the target pedestrian P1 represented by the beacon ID signal of the beacon 20 is low.
For this reason, the information processing apparatus 16 calculates a post-exclusion overlapping area A-Le in which an area overlapping the river LV and the building BL in the overlapping estimation area A-L is excluded from the overlapping estimation area A-L. The post-exclusion overlapping area A-L-e is an area shown by hatching in FIG.
The filtering process by the information processing device 16 is executed in this way.

Further, the information processing device 16 calculates an estimated position ALC that is the center position of the post-exclusion overlapping area ALE. That is, the information processing device 16 treats the calculated estimated position ALC as the current position of the target pedestrian P1 (beacon 20).
Then, the information processing apparatus 16 displays each beacon 20 estimated position A-C on one grid on the display 18 in association with the beacon ID signal, as shown in FIG.

The information processing device 16 uses the radio signal and the reference intensity signal transmitted by the beacon 20 in the next consecutive first intensity switching period, second intensity switching period, and third intensity switching period to estimate the position ALC. Is calculated. That is, the information processing device 16 repeatedly performs the calculation operation of the estimated position ALC at the same cycle as the center reception cycle, for example. Further, the information processing device 16 records the calculated estimated positions ALC in the RAM in time series at the same cycle as the center reception cycle.
The display 18 repeatedly displays the estimated position ALC of the target pedestrian P1 at the same cycle as the center reception cycle, for example. That is, when the target pedestrian P1 moves, the position of the target pedestrian P1 on the map image changes.

In the ROM of the information processing device 16 in the data center 15, the terminal IDs of the smartphones 25A and 25B are recorded.
Therefore, the information processing apparatus 16 displays the position based on the GPS position information of the smartphones 25 </ b> A and 25 </ b> B corresponding to the received terminal ID signal on the map image of the dynamic map DM. That is, the positions of the corresponding smartphones 25A and 25B are displayed so as to overlap with the positions represented by the GPS position information on the map image.

  Furthermore, the information processing device 16 transmits information related to the beacon ID signal of the beacon 20 and the estimated position A-LC to the smartphone 25B every predetermined cycle (for example, the same cycle as the center reception cycle).

For example, when the smartphone 25B receives information related to the beacon ID signal of the beacon 20 (target pedestrian P1) and the estimated position ALC in a predetermined cycle (for example, the same cycle as the center reception cycle), the pedestrian position display application The ECU 27 of the smartphone 25 </ b> B reading “” displays the estimated position ALC on the map image on the display 31. The map image displayed on the display 31 is substantially the same as the map image of FIG. When the beacon 20 further moves, the display 31 displays the map image while scrolling.
Therefore, the family F who has seen the display 31 of the smartphone 25B can recognize in real time where the target pedestrian P1 is currently located.

As described above, the estimated distances (immediately region, near region, and far region) calculated by each smartphone 25A based on the radio signal transmitted from the beacon 20 and the reference intensity signal are not a specific distance. In other words, each estimation area has a width. Therefore, each temporary estimation area calculated by the information processing device 16 based on the estimated distance may include a distance that is greatly deviated from the actual position of the beacon 20.
However, theoretically, the temporary estimation regions A-2 (A-3), A-2 ′ (A-3 ′), and A-2 ″ (A-3) used when obtaining the overlap estimation region A-L. As the number of types ″) increases, the overlap estimation area A-L is less likely to include a distance greatly deviated from the actual beacon 20 position. In other words, the error between the center position of the post-exclusion overlap area ALE obtained from the overlap estimation area A-L and the current position of the pedestrian P1 (beacon 20) is reduced.

  In the present embodiment, the information processing device 16 has various provisional estimation areas A-2 (A-3) of various shapes based on three types of radio signals transmitted from the beacon 20 at substantially the same time and having different radio field intensities. ), A-2 ′ (A-3 ′), and A-2 ″ (A-3 ″). The information processing apparatus 16 overlaps each temporary estimation area A-2 (A-3), A-2 ′ (A-3 ′), and A-2 ″ (A-3 ″) with each other, thereby estimating the overlap. The area A-L is obtained.

Accordingly, it can be estimated that the overlap estimation area A-L includes almost no area representing a distance greatly deviated from the actual position of the beacon 20. In other words, the overlap estimation area A-L represents the actual current position of the beacon 20 more accurately than each temporary estimation area.
Therefore, the estimated position ALC of the beacon 20 finally obtained by the information processing device 16 is highly likely to represent the current position of the beacon 20 at a certain height. That is, there is a high possibility that the error between the obtained estimated position ALC and the actual current position of the beacon 20 is small.

Furthermore, since the radio signal generated by the beacon 20 is a 2.4 GHz band radio wave, this radio signal is easily affected by the surrounding environment. That is, for example, when it is raining in the area represented by the map image, it becomes difficult for each smartphone 25A to receive this radio signal.
However, the beacon 20 transmits a radio signal a plurality of times in each intensity switching period (for example, when the IC chip 22 generates a radio signal every 100 milliseconds and the intensity switching period is 1 second).
Therefore, even if it is raining in the area represented by the map image, there is a high possibility that each smartphone 25A can receive a radio signal transmitted by the beacon 20 in one intensity switching cycle. That is, there is a high possibility that the information processing apparatus 16 can calculate the estimated position ALC of the beacon 20 even if it is raining in the area represented by the map image.

  Note that some temporary estimation areas A-2 (A-3), A-2 ′ (A-3 ′), and A-2 ″ (A-3 ″) do not overlap with other temporary estimation areas. In this case, the information processing apparatus 16 may obtain the overlap estimation area A-L after excluding this part of the temporary estimation area.

In addition, the estimated distances calculated by the plurality of smartphones 25A based on the wireless signals transmitted by the beacon 20 in the first intensity switching period, the second intensity switching period, and the third intensity switching period may all be in the immediately region. For example, this is a case where C1 and C2 shown in FIG. 6 are immediate areas. In this case, the temporary estimation area obtained by the information processing device 16 based on these estimated distances is approximately the same size as one grid.
However, in this case, when the linear distance between the two smartphones 25A calculated by the information processing device 16 based on the GPS position information is longer than twice the upper limit value of the immediate area, at least one smartphone 25A It can be considered that there is an error in the calculation result. Therefore, in this case, the information processing apparatus 16 may obtain the overlap estimation area A-L by excluding this temporary estimation area.

  Next, specific operations executed by the beacon 20, the ECU 27 of each smartphone 25, the ECU 27 of the smartphone 25B, and the information processing device 16 of the data center 15 will be described using the flowcharts of FIGS.

  The IC chip 22 of the beacon 20 repeatedly executes the routine shown in the flowchart of FIG. 12 every time a predetermined time elapses.

First, the IC chip 22 generates a beacon ID signal in step 1201.
Further, the IC chip 22 proceeds to step 1202 and generates a reference intensity signal.
Further, the IC chip 22 proceeds to step 1203 and transmits the beacon ID signal and the reference intensity signal as a set together with the radio signal (radio wave) from the antenna 24 to the outside. The radio field intensity of the radio signal at this time is the magnitude represented by the reference intensity signal.
The IC chip 22 that has finished the processing of step 1203 once ends this routine.

  The ECU 27 of the smartphone 25A possessed by the pedestrian P2 repeatedly executes the process of the flowchart shown in FIG. 13 every time a predetermined time elapses.

  In step 1301, the ECU 27 determines whether the wireless communication antenna 29 has received a beacon ID signal and a reference strength signal from the beacon 20.

  If YES in step 1301, the ECU 27 proceeds to step 1302, and the beacon corresponding to the beacon ID signal received from the smartphone 25A based on the actual strength and the reference strength signal of the radio signal received by the antenna 24 from the beacon 20. An estimated distance up to 20 is calculated.

  The ECU 27 that has finished the processing of step 1302 proceeds to step 1303, and records the beacon ID signal, the reference intensity signal, and the estimated distance together in the RAM.

After completing the processing in step 1303, the ECU 27 proceeds to step 1304, and determines whether or not the GPS receiving antenna 30 receives a GPS position signal.
When it is determined No in step 1304, the ECU 27 once ends this routine.

  If it is determined Yes in step 1304, the ECU 27 proceeds to step 1305 and generates a terminal ID signal.

After completing the processing in step 1305, the ECU 27 proceeds to step 1306 and controls the radio communication antenna 29. As a result, the estimated distance and GPS information set (or GPS position information) recorded (accumulated) in the RAM from the previous reception of the GPS position signal to the reception of the GPS position signal in step 1304 of this routine, and The terminal ID signal is transmitted from the radio communication antenna 29.
The ECU 27 that has finished the processing of step 1306 once ends this routine.

  The information processing device 16 of the data center 15 repeatedly executes the processing of the flowchart shown in FIG. 14 every time a predetermined time elapses.

In step 1401, the information processing apparatus 16 determines whether or not the estimated distance and the GPS information set and the terminal ID signal are received from the plurality of smartphones 25A.
If it is determined No in step 1401, the information processing apparatus 16 once ends this routine.

  When it determines with Yes at step 1401, the information processing apparatus 16 progresses to step 1402, and calculates | requires the estimated position ALC of the beacon 20 according to the above-mentioned procedure.

  The information processing apparatus 16 that has finished the process of step 1402 proceeds to step 1403 and displays the estimated position A-LC on the map image on the display 18.

The information processing apparatus 16 that has finished the process of step 1403 proceeds to step 1404, and transmits information related to the estimated position A-LC to the smartphone 25B.
The information processing apparatus 16 that has finished the processing of step 1404 once ends this routine.

  The ECU 27 of the smartphone 25B repeatedly executes the process of the flowchart shown in FIG. 15 every time a predetermined time elapses.

In step 1501, the ECU 27 determines whether or not a map image is displayed on the display 31. In other words, the ECU 27 determines whether or not the pedestrian position display application is read.
When it is determined No in step 1501, the ECU 27 once ends this routine.

If the determination in step 1501 is Yes, the ECU 27 proceeds to step 1502 and determines whether or not the estimated position ALC of the beacon 20 is received from the information processing device 16.
When it is determined No in step 1502, the ECU 27 once ends this routine.

When it determines with Yes at step 1502, ECU27 progresses to step 1503 and displays the estimated position ALC on the map image of the display 31. FIG.
The ECU 27 that has finished the processing of step 1503 once ends this routine.

  The present invention is not limited to the above embodiments, and various modifications can be employed within the scope of the present invention.

  The standard of the radio wave generated and transmitted by the beacon 20 is not limited to Bluetooth Low Energy. For example, this radio wave standard may be Bluetooth (registered trademark).

  The information terminal for distance estimation and / or the receiving terminal is not limited to the smartphones 25A and 25B. For example, a tablet computer and a notebook personal computer can be used as a distance estimation information terminal and / or a reception terminal.

  The distance estimation information terminal (for example, the smartphone 25A) may include an antenna that can receive information from a satellite of a global navigation satellite system (for example, Galileo) other than GPS.

  Installed in an area represented by the map image of the dynamic map DM as a distance estimation information terminal that calculates an estimated distance to the beacon 20 based on a radio signal transmitted by the beacon 20 and transmits information on the estimated distance to the information processing device 16 A fixed distance estimation information terminal may be used.

  The type of the moving body that moves together with the beacon 20 is not limited to the target pedestrian P1. For example, the moving body may be a bicycle.

Further, a person other than the pedestrian P2 may have a distance estimation information terminal (for example, the smartphone 25A). For example, an occupant of a car may carry a distance estimation information terminal.
However, the moving speed of the bicycle and the car is faster than the target pedestrian P1 and the pedestrian P2. Therefore, when the beacon 20 and / or the distance estimation information terminal moves together with the automobile and / or the bicycle, the beacon transmission period and the intensity switching period of the beacon 20, the beacon transmission information reception period of the distance estimation information terminal and the GPS It is necessary to make the information reception cycle and the center reception cycle of the information processing device 16 shorter than those in the above embodiment. For example, when the driver of a car has an information terminal for distance estimation, the general speed of the car (for example, 50 km / h) is changed to the general speed of the pedestrian (for example, 0.6 m / sec. .16 km / h) divided by each period (for example, “23”) is used as each period. In this way, each radio transmitted by the beacon 20 in the first intensity switching period, the second intensity switching period, and the third intensity switching period even when the driver of the automobile has the distance estimation information terminal. The signal can be treated as being transmitted by the beacon 20 at substantially the same time.

  Further, an information terminal (for example, an information terminal having a car navigation function) fixed to a vehicle (for example, an automobile or a motorcycle) may be used as a distance estimation receiving terminal.

Further, the information processing device information 16 of the data center 15 may transmit the estimated position ALC of the beacon 20 to the distance estimation receiving terminal that moves together with the vehicle (for example, an automobile or a motorcycle). .
In this case, for example, when the distance estimation receiving terminal calculates the distance from its own position to the beacon 20 based on its own position and the estimated position ALC, and this distance is shorter than a predetermined threshold distance In addition, the distance estimation receiving terminal may send an operation signal to a speaker provided in the vehicle. In this case, the speaker issues an alarm when the distance is shorter than the threshold distance, so that the driver of the vehicle can be alerted that the target pedestrian P1 is nearby.

  Further, when this distance is shorter than the threshold distance, the distance estimation receiving terminal may send an operation signal to the vehicle brake device to automatically operate the brake device.

DESCRIPTION OF SYMBOLS 10 ... Position estimation system, 15 ... Data center (position estimation part), 16 ... Information processing apparatus (position estimation apparatus) (radio wave receiving part), 18 ... Display, 20 ... Beacon ( Tag), 22 ... IC chip (strength adjusting unit), 24 ... antenna (transmitting unit), 25A ... smartphone (receiving terminal for distance estimation), 25B ... smartphone (receiving terminal), 27. ..ECU (distance estimation unit), 29... Antenna for wireless communication (terminal side reception unit) (terminal side transmission unit), A-L... Overlap estimation area, A-Le. Rear overlap area, ALC ... estimated position,
P1 ... object pedestrian (moving body), P2 ... pedestrian.

Claims (4)

A transmitter that can move with a mobile body and that transmits a radio wave including a beacon ID signal that is identification information of itself and a reference intensity signal that represents the radio field intensity, and an intensity that changes the radio field intensity at a predetermined period A beacon having an adjustment unit;
A terminal-side receiving unit that receives the radio wave transmitted by the beacon together with the identification information and the reference strength signal; the beacon corresponding to the beacon ID signal based on the actual strength of the received radio wave and the reference strength signal; A distance estimation unit that calculates an estimated distance that is a distance from itself, and a terminal-side transmission that transmits a radio wave together with the terminal ID signal that is identification information of itself, the position information of itself, the beacon ID signal, and the estimated distance A plurality of distance estimation receiving terminals,
The terminal ID signal transmitted by the plurality of distance estimation receiving terminals, the position information, the beacon ID signal, and a radio wave receiving unit that receives the estimated distance together, and the plurality of estimated distances and the plurality of position information. A position estimation unit comprising a position estimation unit for obtaining an estimated position that is the position of the beacon based on
With
The distance estimation unit is an immediate area where the distance between the beacon and the distance estimation receiving terminal is closest, a near area where the distance between the beacon and the distance estimation receiving terminal is farther than the immediate area, and the beacon and the When one of the three areas of the far area far from the near area is calculated as the estimated distance and a plurality of types of reference intensity signals are received from the beacon within a predetermined time In addition, each of the three regions is configured to change the range according to the magnitude of the radio wave intensity corresponding to each reference intensity signal,
The position estimation unit obtains an overlap estimation region that is a region in which a plurality of annular bands or circles representing regions that are centered on the position represented by the position information and separated from the position by the estimated distance are overlapped with each other. And configured to obtain the estimated position from the overlap estimation region,
Mobile beacon location estimation system. The position estimation system for mobile beacons according to claim 1,
The standard of the radio wave transmitted by the transmitter of the beacon is Bluetooth Low Energy.
Mobile beacon location estimation system. In the position estimation system for mobile beacons according to claim 1 or claim 2,
The position estimation unit;
The map data representing an area where the beacon and the plurality of distance estimation receiving terminals are located, and the estimated position based on the overlap estimation area,
Mobile beacon location estimation system. In the position estimation system of the mobile beacon according to any one of claims 1 to 4,
The position estimation device is
A radio wave transmitter that transmits information related to the estimated position to a receiving terminal separate from the receiving terminal for distance estimation,
Mobile beacon location estimation system.

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