JP7036755B2 - Positioning device - Google Patents

Description

The present invention relates to a positioning device, and more particularly to a positioning device that acquires information from a wireless terminal for which distances to each of a plurality of fixed stations are obtained and measures the position of the wireless terminal.

Research and development is being carried out on a positioning system that measures the position of wireless terminals. The wireless terminal measures the distance to each fixed station by transmitting and receiving a wireless signal to and from a plurality of fixed stations whose positions are known. The information processing device acquires the distance measurement result from the wireless terminal and obtains the position of the wireless terminal based on the distance between the wireless terminal and each fixed station. Such a positioning system is expected to be applied to confirmation of the whereabouts of people in a building, inventory management in a factory, and the like.

As a positioning system, the following Patent Document 1 describes a system for searching the position of a moving body holding a beacon device. In this system, each of the plurality of mobile terminals receives the beacon signal transmitted from the beacon device and obtains the distance to the beacon device. The mobile search server acquires information indicating the position of each mobile terminal and the distance to the beacon device from each mobile terminal, and obtains the position of the beacon device.

Further, Patent Document 2 describes a wireless tag distance measuring device. The wireless tag distance measuring device transmits a distance measuring signal to the wireless tag, and receives an arrival signal transmitted from the wireless tag accordingly. The wireless tag distance measuring device measures the distance from the wireless tag distance measuring device to the wireless tag based on the time from the transmission of the distance measurement signal to the reception of the arrival signal. In this document, it is described that the position of the wireless tag is obtained based on the distance measurement result by a plurality of wireless tag distance measuring devices.

Japanese Unexamined Patent Publication No. 2016-217931 Japanese Unexamined Patent Publication No. 2009-174971

In a system for positioning a wireless terminal, the positioning of the wireless terminal is performed using a wireless signal. Therefore, the positioning accuracy may not be sufficient depending on the propagation condition of the radio signal.

An object of the present invention is to obtain the position of a wireless terminal with high accuracy.

INDUSTRIAL APPLICABILITY In a positioning device for determining the position of a wireless terminal, the wireless terminal transmits and receives a wireless signal to and from a plurality of fixed stations, and a temporary distance measurement value to each fixed station is measured a plurality of times. The variation between the distance measurement value to each fixed station and the provisional distance measurement value obtained multiple times for each fixed station based on the provisional distance measurement value obtained multiple times. The degree is obtained, and the positioning device acquires the distance measurement value obtained for each fixed station and the variation degree obtained corresponding to the distance measurement value from the wireless terminal, and temporarily positions the position. In the determination process, when three are selected from the plurality of fixed stations, the temporary position of the wireless terminal is obtained based on the three distance measurement values for the three selected fixed stations. In the measurement process and the second measurement process for obtaining the total weighting coefficient for the temporary position, the total weighting coefficient is an individual weighting coefficient based on the degree of variation corresponding to each distance measurement value, and the temporary position is used. A plurality of temporary position determination processes including a second measurement process, which is a value obtained by synthesizing the three fixed stations that contributed to the determination, are selected from the plurality of fixed stations. Execute for each of the combinations, and execute the position determination process for determining the position of the wireless terminal by weighting and synthesizing the temporary positions obtained for each of the combinations using the total weighting coefficient obtained for each of the combinations. It is characterized by doing.

Desirably, the individual weighting coefficient is a value as the degree of variation of the provisional distance measurement value obtained over a plurality of times is larger.

Desirably, the total weighting coefficient is a value obtained by adding or multiplying the individual weighting coefficients for the three fixed stations that contributed to obtaining the temporary position.

Desirably, the weighted composition includes an operation of adding and summing the coordinate values representing the temporary positions to the values adjusted according to the total weighting coefficient corresponding to the temporary positions for the plurality of the combinations.

According to the present invention, the position of the wireless terminal can be obtained with high accuracy.

It is a figure which shows the positioning system. It is a figure which shows the example of the hardware of a wireless terminal. It is a figure which shows the example of the hardware of an information processing apparatus.

(1) Outline of Positioning System FIG. 1 shows a positioning system 10 according to an embodiment of the present invention. The positioning system 10 includes a wireless terminal 12, a plurality of (M) fixed stations 14-1 to 14-M, a network wireless device 16, a communication line 18, and an information processing device 20.

The wireless terminal 12 transmits and receives radio signals to and from a plurality of fixed stations 14-1 to 14-M, and measures the distance to each fixed station. The network wireless device 16 performs wireless communication with the wireless terminal 12 and acquires measurement information indicating a measurement result by the wireless terminal 12. The network wireless device 16 transmits the measurement information acquired from the wireless terminal 12 to the information processing device 20 via a communication line 18 such as the Internet. The information processing device 20 measures the position of the wireless terminal 12 based on the measurement information.

(2) Processing executed by the positioning system The processing executed by the positioning system 10 according to the present embodiment will be specifically described. The wireless terminal 12 is a distance to the fixed station 14-k N times (N is an integer of 2 or more) for one fixed station 14-k out of M fixed stations 14-1 to 14-M. Is measured as a temporary distance measurement value. Then, the final distance measurement value d (k) is obtained based on the N temporary distance measurement values obtained for the fixed station 14-k. The distance measurement value d (k) may be a statistical value indicating a tendency of the magnitude of N provisional distance measurement values such as an average value or a median value of N provisional distance measurement values.

The wireless terminal 12 further obtains a degree of variation σ (k) for N provisional distance measurement values that contribute to the distance measurement values d (k) obtained for the fixed station 14-k. The degree of variation σ (k) may be the standard deviation or variance for N provisional distance measurements. Further, it may be a value obtained by subtracting the minimum value from the maximum value among the N temporary distance measurement values. The smaller the degree of variation σ (k), the higher the possibility that the measured distance value d (k) was obtained with high accuracy.

The wireless terminal 12 executes the same processing for the other fixed stations, and for each of the fixed stations 14-1 to 14-M, the distance measurement values d (k) (k = 1 to M) and the degree of variation σ ( The measurement information D (k) associated with k) is obtained.

The wireless terminal 12 performs wireless communication with the network wireless device 16 and transmits measurement information D (1) to D (M) to the network wireless device 16. The network wireless device 16 receives the measurement information D (1) to D (M) and transmits the measurement information D (1) to D (M) to the information processing device 20 via the communication line 18. The information processing device 20 receives measurement information D (1) to D (M) from the network wireless device 16 via the communication line 18.

The information processing apparatus 20 acquires the distance measurement values d (1) to d (M) from the measurement information D (1) to D (M). Then, for each of the _three combinations of MCs that select three from the distance measurement values d (1) to d ( _M ), the temporary position Qv _j (p _j , q _j , r _j ) of the wireless terminal 12 is set. Ask. Here, p _j , q _j , and r _j indicate three integers selected from the integers 1 to M. j is a number for identifying the type of combination (combination identification number), and is an integer of 1 to _{MC 3} . The temporary position Qv _j (p _j , q _j , r _j ) is the three distance measurement values d (p _j ), d (q _j ) and d selected from the distance measurement values d (1) to d (M). It is a temporary position obtained based on ( _rj ) and is represented by a two-dimensional vector (two-dimensional coordinate value). The code "v" in the code "Qv _j (p _j , q _j , r _j )" indicates that it is a vector quantity.

That is, the information processing apparatus 20 stores the positions of the fixed stations 14-1 to 14-M in advance. The wireless terminal 12 has a circle centered on the position of the fixed station 14-p _j and having a radius d (p _j ), a circle centered on the position of the fixed station 14-q _j and having a radius d (q _j ), and a circle. The coordinate values of the intersections of circles centered on the position of the fixed station 14-r _j and having a radius of d (r _j ) are obtained as temporary positions Qv _j (p _j , q _j , r _j ).

The information processing apparatus 20 has a temporary position Qv _j (p _j , q _j , r _j ) obtained for each of the _three combinations of MCs that select three from the distance measurement values d (1) to d ( _M ). For each of the above, the total weighting coefficient _Wj is determined based on the weighting determination process described later. The information processing apparatus 20 obtains the position Pv of the wireless terminal 12 according to (Equation 1). The code "v" in the code "Pv" indicates that it is a vector quantity.

(Equation 1) is a weighted combination of temporary positions Qv _j for _three combinations of MCs in which three distance measurement values d (1) to d ( _M ) are selected. This weighting composition is an operation in which the coordinate values representing the temporary position Qv _j are adjusted according to the total weighting coefficient _{W j} corresponding to the temporary position Qv _j , and the addition and summing are performed for the _three combinations of MC.

(Number 1)
Pv = (ΣW _j · Qv _j ) / (W ₁ + W ₂ + ... + _WC )

However, C = _{MC 3} . Σ indicates that it is the total value of addition from j = 1 to _{MC 3} .

(3) Weighting determination process A weighting determination process for determining the total weighting coefficient _Wj will be described. The information processing apparatus 20 obtains an individual weighting coefficient w (k) based on the degree of variation σ (k) included in the measurement information D (k) corresponding to one fixed station 14-k. Here, the individual weighting coefficient w (k) is a positive number whose value becomes smaller as the degree of variation σ (k) becomes larger. The weighting coefficient w (k) may be defined as, for example, (Equation 2).

(Number 2)
w (k) = S-σ (k)
However, S is a constant, and when S—σ (k) is a value less than 1, w (k) is set to 1.

Further, the weighting coefficient may be defined as (Equation 3).

(Number 3)
w (k) = 10-(| 50-x (k) |) / 2
However, the degree of variation σ (k) is the standard deviation, the distance measurement value d (k) is the average value of N provisional distance measurement values, and x (k) is obtained based on the standard deviation and the mean value. It is a deviation value. When the value on the right side is less than 1 in (Equation 3), w (k) is set to 1.

The information processing apparatus 20 obtains a total weighting coefficient _Wj obtained by synthesizing individual weighting coefficients for each of the _three combinations of MCs that select three from the weighting coefficients w (1) to w ( _M ). That is, the total weighting coefficient W _j is obtained based on the three weighting coefficients w (p _j ), w (q _j ) and w (r _j ) selected from the weighting coefficients w (1) to w (M). The value. The total weighting coefficient W _j may be defined as an addition total value as in (Equation 4).

(Number 4)
W _j = w (p _j ) + w (q _j ) + w (r _j )

Further, the total weighting coefficient W _j may be defined as a total multiplication value as in (Equation 5).

(Number 5)
W _j = w (p _j ), w (q _j ), w (r _j )

(4) Specific Example A specific example in which M = 4, that is, the positioning system 10 includes four fixed stations 14-1 to 14-4 will be described. The information processing apparatus 20 receives measurement information D (1) to D (4) for fixed stations 14-1 to 14-4 via the communication line 18.

The information processing apparatus 20 acquires the distance measurement values d (1) to d (4) from the measurement information D (1) to D (4), respectively. Then, the temporary position Qv _j of the wireless terminal 12 is obtained for each of the combinations that select three from the distance measurement values d (1) to d (4).

There are the following four combinations for selecting three distance measurement values d (1) to d (4). (I) Combination of distance measured values d (1), d (2) and d (3) (j = 1)
(Ii) Combination of distance measured values d (1), d (2) and d (4) (j = 2)
(Iii) Combination of distance measured values d (1), d (3) and d (4) (j = 3)
(Iv) Combination of distance measurements d (2), d (3) and d (4) (j = 4)
The information processing apparatus 20 acquires the degree of variation σ (1) to σ (4) from the measurement information D (1) to D (4), respectively. Then, the individual weighting coefficients w (1) to w (4) are obtained based on the degree of variation σ (1) to σ (4), respectively.

The information processing apparatus 20 obtains the total weighting coefficients W1 to W4 according to (Equation ₄ ) or (Equation 5) for the combination identification numbers j = ₁ to 4. When (Equation 4) is followed, the information processing apparatus 20 obtains the total weighting coefficient as in (Equation 6).

(Number 6)
W ₁ = w (1) + w (2) + w (3)
W ₂ = w (1) + w (2) + w (4)
W ₃ = w (1) + w (3) + w (4)
W ₄ = w (2) + w (3) + w (4)

Alternatively, the information processing apparatus 20 obtains the total weighting coefficient according to (Equation 5) as in (Equation 7).

(Number 7)
W ₁ = w (1), w (2), w (3)
W ₂ = w (1), w (2), w (4)
W ₃ = w (1), w (3), w (4)
W ₄ = w (2), w (3), w (4)

The information processing apparatus 20 obtains the position Pv of the wireless terminal 12 according to (Equation 1) as in (Equation 8).

(Number 8)
Pv = (W ₁ , Qv ₁ + W ₂ , Qv ₂ + W ₃ , Qv ₃ + W ₄ , Qv ₄ )
/ (W ₁ + W ₂ + W ₃ + W ₄ )

(5) Effect In such processing, the larger the total weighting coefficient W _j with respect to the temporary position Qv _j , the greater the temporary position Qv _j contributes to the position Pv. The total weighting coefficient W _j is an individual weighting coefficient w (p _j ) of each of the three distance measurement values d (p _j ), d (q _j ) and d (r _j ) that contributed to obtaining the temporary position Qv _j . , W (q _j ) and w (r _j ) have larger values. Then, the degree of variation that led to the determination of the distance measurement values d (p _j ), d (q _j ) and d (r _j ) was small, and the distance measurement values d (p _j ), d (q _j ) and d ( The higher the possibility that r _j ) is obtained with high accuracy, the larger the individual weighting coefficients w (p _j ), w (q _j ) and w (r _j ).

Therefore, according to the positioning system 10 according to the present embodiment, the smaller the degree of variation corresponding to the three distance measurement values from which the temporary position Qv _j is obtained, that is, the higher the accuracy of these three distance measurement values is. The higher the probability of being obtained, the greater the temporary position Qv _j contributes to the position Pv. As a result, the position Pv becomes a vector quantity in which the contribution of the distance measurement value obtained with high accuracy is large, and the measurement accuracy is improved.

(6) Example of hardware FIG. 2 shows an example of the hardware of the wireless terminal 12. The wireless terminal 12 includes a wireless unit 32 and an information processing unit 34. The wireless unit 32 wirelessly transmits the information acquired from the information processing unit 34 to each fixed station 14-k or the network wireless device 16. Further, the radio signal transmitted from each fixed station 14-k or the network radio device 16 is received, and the information included in the radio signal is output to the information processing unit 34.

The information processing unit 34 includes a distance measurement unit 36, a variation measurement unit 38, and a measurement information generation unit 40. The information processing unit 34 may include a processor that executes a program. In this case, the information processing unit 34 internally configures each component (distance measuring unit 36, variation measuring unit 38, and measurement information generation unit 40) by executing the program.

The distance measuring unit 36 transmits and receives radio signals to and from each of the fixed stations 14-1 to 14-M via the wireless unit 32, and obtains a temporary distance measurement value to each fixed station N times. The distance measuring unit 36 obtains the distance measured value to each fixed station based on the provisional distance measured value obtained over N times. The variation measuring unit 38 obtains the degree of variation of the provisional distance measured values obtained over N times for each fixed station, that is, each distance measured value. The measurement information generation unit 40 generates measurement information D (k) for each of the fixed stations 14-1 to 14-M, and measures information D (1) to D (1) to D (to the network wireless device 16 via the wireless unit 32). M) is transmitted wirelessly.

FIG. 3 shows an example of the hardware of the information processing apparatus 20. The information processing apparatus 20 includes an interface 50 and an information processing unit 52. The information processing device 20 may be a computer that functions as a server. The interface 50 connects the information processing unit 52 to the communication line 18. The information processing unit 52 includes an information acquisition unit 54, a temporary position determination unit 56, and a position determination unit 58. The information processing unit 52 may include a processor that executes a program. In this case, the information processing unit 52 internally configures each component (information acquisition unit 54, temporary position determination unit 56, and position determination unit 58) by executing the program.

The information acquisition unit 54 receives the measurement information D (1) to D (M) from the communication line 18 via the interface 50, and the distance measurement value d (k) obtained for each fixed station and the distance measurement value d. The degree of variation σ (k) obtained in response to (k) is acquired from the measurement information D (k).

The temporary position determination unit 56 executes the temporary position determination process for each of a plurality of combinations that select three fixed stations from the fixed stations 14-1 to 14-M. The temporary position determination process includes the following first measurement process and second measurement process. In the first measurement process, when three fixed stations 14-1 to 14-M are selected, three fixed stations 14-p _j , 14-q _j , and 14-r _j are selected. This is a process of obtaining a temporary position Qv _j of the wireless terminal 12 based on the measured distance values d (p _j ), d (q _j ) and d (r _j ). The second measurement process is a process of obtaining the total weighting coefficient W _j for the temporary position Qv _j . The total weighting coefficient W _j is an individual weighting coefficient based on the degree of variation obtained corresponding to each distance measurement value, and the three fixed stations 14-p _j and 14-q _j that contributed to obtaining the temporary position Qv _j . , And 14- _rj are the values obtained by synthesizing. The composition of individual weighting coefficients includes total addition and total multiplication.

The position determining unit 58 uses the total weighting coefficient W _j obtained for each combination to weight-synthesize the temporary position Qv _j obtained for each combination, and obtains the position Pv of the wireless terminal 12.

10 Positioning system, 12 wireless terminals, 14-k fixed stations, 16 network wireless devices, 18 communication lines, 20 information processing devices, 32 wireless units, 34, 52 information processing units, 36 temporary distance measurement units, 38 variation measurement units, 40 measurement information generation unit, 50 interface, 54 information acquisition unit, 56 temporary position determination unit, 58 position determination unit.

Claims (4)

In a positioning device that determines the position of a wireless terminal
The wireless terminal sends and receives a radio signal to and from a plurality of fixed stations, obtains a temporary distance measurement value to each fixed station multiple times, and obtains the temporary distance measurement multiple times. Based on the values, the distance measurement value to each fixed station and the degree of variation of the provisional distance measurement value obtained multiple times for each fixed station were obtained.
The positioning device is
The distance measurement value obtained for each of the fixed stations and the degree of variation obtained corresponding to the distance measurement value are acquired from the wireless terminal.
Temporary position fixing process
The first measurement process for obtaining a temporary position of the wireless terminal based on the three distance measurement values for the three selected fixed stations when three are selected from the plurality of fixed stations.
In the second measurement process for obtaining the total weighting coefficient for the temporary position, the total weighting coefficient contributes to obtaining the temporary position by using an individual weighting coefficient based on the degree of variation corresponding to each distance measurement value. The second measurement process, which is a value obtained by synthesizing the three fixed stations,
The temporary position-fixing process including the above is executed for each of the plurality of combinations for selecting the three fixed stations from the plurality of fixed stations.
Positioning is characterized in that the temporary position obtained for each combination is weighted and synthesized using the total weighting coefficient obtained for each combination, and a position determination process for obtaining the position of the wireless terminal is executed. Device. In the positioning apparatus according to claim 1,
The individual weighting coefficient is a positioning device, characterized in that the larger the degree of variation in the provisional distance measurement values obtained over a plurality of times, the smaller the value. In the positioning apparatus according to claim 2,
The positioning device is characterized in that the total weighting coefficient is a value obtained by adding or multiplying the individual weighting coefficients of the three fixed stations that have contributed to obtaining the temporary position. In the positioning apparatus according to any one of claims 1 to 3,
The weighted composition is
A positioning device comprising an operation of adding and summing a coordinate value representing the temporary position and a value adjusted according to the total weighting coefficient corresponding to the temporary position for a plurality of the combinations.

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