JP4645489B2 - Positioning device - Google Patents

Description

  The present invention relates to a positioning device that receives a radio wave radiated or reflected from a target whose position is to be known and calculates the position of the target.

  In the positioning device, radio waves radiated or reflected from the target are received by multiple sensors, and the position of the target is calculated based on the arrival time difference between the received radio waves. It is necessary to receive at the correct timing. For this purpose, it is necessary for each sensor to establish highly accurate time synchronization. The sensors are connected by a cable, and the sensors are operated in synchronization with each other with the same clock. However, when multiple sensors are installed in close proximity, they can be connected together using a wiring board, etc., but when the sensors are installed at positions separated from each other, individual cables can be connected between the sensors. It is necessary to prepare a large number of cables for the connection and connection work, which is disadvantageous in terms of cost. In addition, when the sensors themselves move, it is difficult to connect the sensors with cables. As a method for solving this problem, there is a method in which the arrival time of a radio wave is observed with each sensor including a clock error, and the clock error is corrected by subsequent processing (for example, Patent Document 1). In the method of Patent Document 1, a transmitting station is placed at a known position, radio waves from the transmitting station are received by each sensor, and a time difference between the radio waves is calculated to calculate a clock error between the sensors. Is. When calculating the target position, the arrival time difference of the radio wave from the target is corrected with the previously determined clock error, and the target position is calculated based on the correction value.

JP 2001-272448 A

  In the conventional positioning device, the arrival time difference of the radio wave from the target is corrected using a previously determined clock error, and the target position is calculated based on the correction value. In order to obtain this, it is necessary to provide a separate transmission station, and the apparatus becomes large correspondingly.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a positioning device that can correct a clock error between sensors by processing in the device itself.

A positioning device according to the present invention is a positioning device that receives a radio wave radiated or reflected from a target by a plurality of sensors and calculates a target position based on a difference in arrival time of the received radio waves, and is received by each sensor a plurality of times. An arrival time difference calculation unit that calculates the arrival time difference of the received radio wave, and a positioning unit that measures the clock error between the sensors and the target position at each time when the radio wave is received based on the calculated arrival time difference between the sensors. The positioning unit is configured to calculate a distance obtained by multiplying the corrected arrival time difference of the radio wave between the input sensors by the speed of the radio wave to be equal to the difference in the propagation distance of the radio wave for each reception time of the radio wave. And calculate the provisional position of the target at each time by solving these equations for each reception time, and divide the difference between the provisional position of this target and each sensor by the speed of the radio wave. Each time A mismatch time calculation unit that calculates a mismatch time at each time by subtracting from the difference in arrival time of radio waves between sensors, and a temporary clock error calculation unit that calculates a temporary clock error between sensors based on the calculated mismatch time Subtracting the provisional clock error calculated by the provisional clock error calculation unit from the difference between arrival times of radio waves to obtain a corrected arrival time difference of radio waves between the sensors and outputting the difference to the provisional positioning unit, and according to the determination criteria, the provisional clock error A series of positioning processes by the positioning unit, the mismatch time calculation unit, and the provisional clock error calculation unit are completed, and the target temporary position and the provisional clock error obtained in each processing are determined as the final target position and clock error. Or a positioning process control unit that performs control so that the series of positioning processes are continuously performed again .

  According to the present invention, the arrival time of radio waves is observed with a clock error included between the sensors, and the clock error is corrected in the subsequent positioning process. Accordingly, there is no need to consider cable connection for synchronization between sensors, and there is no need to separately install a transmitting station for correcting clock errors.

Embodiment 1 FIG.
1 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 1 of the present invention. In the figure, a plurality of sensors 1 ₁ to 1 _N are means for receiving a radio wave radiated from a target or reflected by the target a plurality of times. Here, N is the total number of sensors.

  The arrival time difference calculation unit 2 is a means for calculating the arrival time difference of radio waves received by each sensor a plurality of times. The positioning unit 3 is means for calculating a clock error between the sensors and a target position at each time when the radio wave is received based on the arrival time difference of the radio wave between the sensors.

  The positioning unit 3 includes a collective positioning unit 31. The collective positioning unit 31 calculates an equation that the distance obtained by multiplying the time difference of the radio waves by the time of subtracting the clock error between the sensors and the speed of the radio waves is equal to the difference in the radio wave propagation distance. It is a means for measuring the position of the target at each time at which the clock error between the sensors and the radio wave are received by creating them at each reception time and combining them.

Next, the principle of the present invention will be described. In the sensor 1 ₁ to 1 _N, emitted from the target, or when receiving the radio wave reflected by a target, the sensor observes the arrival time which has received the radio wave. This method will be described by taking sensor _n (1 ≦ n ≦ N) as an example.

First, in the sensor _n , the received signal is down-converted to a low frequency and converted into a digital signal by an A / D converter (sampling time is set to Δt). The digital received signal of the sensor 1 _n when the digital signal sampling number is i is represented as q _n (i). Here, it is assumed that the signal waveform of the radio wave from the target is known, and the known signal waveform is hereinafter referred to as a reference signal and represented by q _r (i). However, it is assumed that the reference signal has been converted to the same frequency as the signal received by the sensor. Then, the number of points (integer) in the correlation process is set to L, and the sample point h is varied to obtain h that maximizes the magnitude | f _n (h) | of the correlation function f _n (h) in the equation (1). Note that q _r (i) ^* means a complex conjugate of q _r (i).

Now, suppose that | f _n (h) | becomes maximum when h = h _n . Since this indicates that the signal received by the sensor 1 _n is similar to the reference signal, h _n · Δt is the arrival time τ _{n at} which the sensor 1 _n received the radio wave from the target.
τ _n = h _n · Δt (2)

In the following, the arrival times observed at multiple times are handled. Therefore, when the time when the radio wave from the target is observed is t _k (1 ≦ k ≦ K, k represents the order of observation with natural numbers, and K represents the total number of observations), observation is performed with the sensor 1 _n at time t _k . Is expressed as τ _n ^(k) .

Each sensor observes radio wave arrival times τ _n ^(k) (1 ≦ n ≦ N, 1 ≦ k ≦ K) at a plurality of different times t _k (1 ≦ k ≦ K) as described above. It transmits to the arrival time difference calculation unit 2. Hereinafter, t _k is referred to as observation time.

The arrival time difference calculation unit 2 calculates the arrival time difference of the radio wave from the target received by each sensor at the observation time t _k (1 ≦ k ≦ K) output from the sensors 1 ₁ to 1 _N. Now, at the observation time t _k , the arrival time of the radio wave received by the sensor 1 _n (1 ≦ n ≦ N) is τ _n ^(k) , and the radio wave received by the sensor 1 _m (1 ≦ m ≦ N, n ≠ m). Is the arrival time τ _m ^(k) . In this case, the arrival time difference calculation unit 2 calculates the arrival time difference Δτ _{n, m} ^(k) of the radio wave at the observation time t _{k according to the} equation (3).
Δτ _{n, m} ^(k) = τ _n ^(k) −τ _m ^(k) (3)

In the above description, the radio wave from the target is known. However, the arrival time can be obtained even when the radio wave is unknown. Specifically, the digital signal q _n (i) received by the sensor 1 _n and the digital signal q _m (i) received by the sensor 1 _m are transmitted, and correlation processing as shown in the equation (4) is performed. .

Then, h that maximizes f ′ _{n, m} (h) is obtained, and this is multiplied by Δt to obtain a radio wave arrival time difference Δτ _{n, m} .
Δτ _{n, m} = h · Δt

  In the description so far, the method of obtaining the arrival time difference using the correlation processing has been described. However, the present invention is not limited to this, and the arrival time difference obtained by another method may be obtained.

The positioning unit 3 generates a plurality of equations in the collective positioning unit 31 based on the arrival time difference Δτ _{n, m} ^(k) (n ≠ m, 1 ≦ k ≦ K) of the radio wave output from the arrival time difference calculation unit 2. The target position is calculated by solving them. A specific processing method will be described.

The time difference Δτ _{n, m} ^(k) of radio waves at the observation time t _k of the sensor 1 _n and the sensor 1 _m includes a clock error. If this clock error is ε _{n, m} (unknown number), (Δτ _{n, m} ^(k) −ε _{n, m} ) is the arrival time difference that does not include the clock error. For this reason, the distance obtained by multiplying (Δτ _{n, m} ^(k) −ε _{n, m} ) by the radio wave velocity c is the difference between “distance from sensor 1 _n to target” and “distance from sensor 1 _m to target”. Is equal to Therefore, equation (5) is established.

Here, [X _n , Y _n , Z _n ] are the coordinates (known) of the sensor 1 _n , [X _m , Y _m , Z _m ] are the coordinates (known) of the sensor 1 _m , and [x ^(k) y ^{(k )} z ^(k) ] is the target coordinates (unknown) at the observation time t _k . The above equation at the observation time t _k is established by the number of sensors minus one. Therefore, if the total number of sensors is N, (N-1) equations are established. In addition, the number of times the radio wave is received from the target is K times (observation time is t _k (1 ≦ k ≦ K)), and the equation like equation (5) at each observation time t _k is (N−1) Since this holds, (N−1) × K equations are established in total.

On the other hand, the unknowns in equation (5) are related to the target position [x ^(k) , y ^(k) , z ^(k) ] and related to the clock error ε _{n, m} . Among these, the unknowns [x ^(k) , y ^(k) , z ^(k) ] of the target positions are different for each observation time t _k (1 ≦ k ≦ K), and the number of observations is K × 3 × K. Become. Further, the clock error ε _{n, m} between the sensors is considered not to fluctuate abruptly, and therefore becomes constant regardless of the radio wave observation time t _k (1 ≦ k ≦ K) and becomes (N−1). Therefore, the total number of unknowns included in (N−1) × K equations is ((N−1) + 3K). Therefore, when the condition of equation (6) is satisfied, the number of unknowns is equal to the number of equations, and the unknowns can be determined. However, since the arrival time difference may include an observation error, the equation (5) does not always intersect at one point. In this case, the unknown is calculated by obtaining a least square solution.
(N−1) × K = (N−1) + 3K (6)

  For example, when the number of sensors N is 5, the number of observations K is 4, and an unknown number can be determined. If there are more equations than unknowns, the least squares solution is obtained to calculate the unknowns.

  The collective positioning unit 31 calculates the unknowns (target position and clock error) as described above.

  The positioning unit 3 may include a motion model setting unit 32 and a motion model positioning unit 33 as shown in FIG. In this case, the motion model setting unit 32 sets whether the target movement whose position is to be known is constant velocity linear motion, constant acceleration linear motion, or the like. The motion model positioning unit 33 creates a plurality of equations based on the result set by the motion model setting unit 32, and calculates the target position by combining these equations.

  An example in which the constant velocity linear motion is set by the motion model setting unit 32 will be described below.

In the case of constant velocity linear motion, the target position [x ^(k) , y ^(k) , z ^(k) ] at the observation time t _k can be expressed as in equations (7) to (9).
x ^(k) = x ⁽¹⁾ + v _x · Δt _k (7)
y ^(k) = y ⁽¹⁾ + v _y · Δt _k (8)
z ^(k) = z ⁽¹⁾ + v _z · Δt _k (9)
Δt _k = t ₁ −t _k (10)
Here ^{[x (1) y (1} ) z (1)] is the target coordinates in the observation time _{t 1} (unknown), _{v x} is the velocity of the x-axis direction of the target (unknown), _{v y} is the target The speed in the y-axis direction (unknown), v _z is the target speed in the z-axis direction. An equation created by the motion model positioning unit 33 is obtained by substituting this into equation (5), and is as shown in equation (11).

These equations are obtained as in the case of the collective positioning unit 31 (N−1) × K. On the other hand, the unknowns are the target position [x ⁽¹⁾ , y ⁽¹⁾ , z ⁽¹⁾ ] at the observation time t _1, the target speed [v _x , v _y , v _z ], the clock error ε _{n, m} Become. The number of unknowns (the position of the observation time t ₁ and the target speed) regarding the target position is a constant value 6 regardless of the number of observations K ₁ , and the number of clock errors is the same as in the collective positioning unit 31 (N -1). Therefore, the condition for obtaining an equation more than the number of unknowns is as shown in equation (12). However, since the arrival time difference may include an observation error, the equation (12) does not always intersect at one point. In this case, the unknown is calculated by obtaining a least square solution.
(N−1) × K ≧ (N−1) +6 (12)

  For example, when the number of sensors N is 5, K ≧ 5/2. Therefore, it is possible to estimate the unknown even when the number of observations K = 3. Since the collective positioning unit 31 has K ≧ 4 when N = 5, the motion model setting unit 33 can calculate the target position with a smaller number of observations. If there are more equations than unknowns, the unknowns are calculated by solving a least squares solution.

  The motion model positioning unit 33 calculates a target position and a clock error by solving a large number of equations such as the equation (11) as described above and solving them. It should be noted that the conditions under which the target position can be measured shown in Expression (12) are different depending on the exercise model set by the exercise model setting unit 32.

  As described above, according to the first embodiment, based on the arrival time difference between the sensors calculated by the arrival time difference calculation unit 2, the clock error between the sensors and the target position at each time when the radio waves are received are determined. In particular, the positioning unit 3 is obtained by multiplying the time obtained by subtracting the clock error between the sensors from the difference in radio wave arrival time between the sensors in the collective positioning unit 31 by the radio wave speed. An equation that the distance is equal to the difference in the propagation distance of the radio wave is created for each reception time of the radio wave, and by combining these equations, the clock error between the sensors and the target position at each time the radio wave is received are I am trying to calculate.

  Therefore, it is possible to correct a clock error between sensors in the positioning device. Therefore, there is no need to synchronize between sensors, there is no need to consider cable connection for synchronizing sensors in accordance with sensor placement, sensor movement, etc., and to correct clock errors There is no need to install a separate transmitter station.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 2 of the present invention. In the figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted in principle. The positioning unit 3 according to the second embodiment includes a provisional positioning unit 34, a mismatch time calculation unit 35, a provisional clock error calculation unit 36, and a positioning process control unit 37.

The provisional positioning unit 34, 'with _{n, m} and ^(k), (13) a target in temporary position at the measurement time t _k by equation [x' radio wave correction TDOA Δτ outputted from the positioning process controller 37 ^{( k)} , y ' ^(k) , z' ^(k) ].

If there is no corrected arrival time difference Δτ ′ _{n, m} ^{(k) of} the radio wave output from the positioning processing control unit 37, the arrival time difference Δτ _{n, m} ^(k) itself output from the arrival time difference calculation unit 2 is used as the radio wave. Instead of the corrected arrival time difference Δτ ′ _{n, m} ^(k) , the target provisional position is calculated by substituting into the equation (13).

Unlike the formula (5) of the collective positioning unit 31 of the first embodiment, the temporary positioning unit 34 estimates a temporary target position that ignores the clock error. The unknown in equation (13) is only the target provisional position [x ′ ^(k) , y ′ ^(k) , z ′ ^(k) ], and therefore provisional if an equation such as equation (13) holds 3 or more. The position can be calculated. Since the positioning equation (13) is established with the number of sensors minus one, the target provisional position can be calculated when the number of sensors N is 4 or more. However, since the radio wave arrival time difference Δτ ′ _{n, m} ^(k) includes a clock error, the positioning equation (13) does not always intersect at one point. In that case, the target provisional position is calculated so as to obtain a least squares solution. Further, even when there are more equations than unknowns, the target provisional position is calculated by obtaining the least squares solution.

  The provisional position measurement unit 34 obtains the target provisional position as described above, and outputs the target provisional position to the mismatch time calculation unit 35.

The mismatch time calculation unit 35 subtracts the time obtained by dividing the difference between the target temporary position obtained by the temporary position measurement unit 34 and the distance between each sensor by the speed of the radio wave from the arrival time difference of the radio wave between the sensors. Then, it is calculated as a mismatch time at each time. This process is expressed by equation (14). A difference between the target temporary position output from the temporary positioning unit 34 and the distance between the sensor 1 _n and the target temporary position and the distance between the sensor 1 _m is obtained.

Next, the time (the second term of the equation) is obtained by dividing the difference between the target temporary position and the distance of each sensor by the radio wave velocity c. The obtained time (the second term of the equation) is subtracted from the arrival time difference Δτ _{n, m} ^{(k) of} the radio wave output from the arrival time difference calculation unit 2 to obtain a mismatch time ε ′ _{n, m} ^(k) .

  The mismatch time calculation unit 35 outputs the mismatch time calculated as described above to the provisional clock error calculation unit 36.

The mismatch time ε ′ _{n, m} ^(k) is due to the clock error between sensors. Therefore, the provisional clock error calculation unit 36 calculates a provisional clock error based on the mismatch time at each time. The provisional clock error calculation unit 36 includes an average processing unit 361 as shown in FIG.

The average processing unit 361 obtains an average value for the mismatch time ε ′ _{n, m} ^(k) (1 ≦ k ≦ K) of the sensor 1 _n and the sensor 1 _m as shown in the equation (15), and this is obtained as the sensor 1 _Let tentative clock error ε ″ _{n, m} for _n and sensor 1 _m .

Further, the provisional clock error calculation unit 36 may include a weighting processing unit 362 as shown in FIG. In this case, the weighting processing unit 362 performs weighting by multiplying the mismatch time ε ′ _{n, m} ^(k) output from the mismatch time calculation unit 35 by a weighting coefficient φ ^(k), which will be described later. Calculated as a clock error ε ″ _{n, m} .

As the weighting coefficient φ ^(k) , for example, “New GPS Surveying Basics”, Takuya Tsuchiya, written by Hiromichi Tsuji, edited by Japan Surveying Association, the geometric relationship between the target position and the sensor position. What is necessary is just to use a reduction rate of the target position estimation accuracy (geometric low accuracy reduction rate: GDOP) or the like. Here, a method of calculating the weighting coefficient φ ^(k) will be described.

Now, it is assumed that the number of sensors N is 4, and the provisional position of the target calculated by the provisional positioning unit 34 is [x ′ ^(k) , y ′ ^(k) , z ′ ^(k) ]. Then, the provisional position of the target, the sensor 1 ₁ and the sensor 1 ₂ and equations using the arrival time difference Δτ _1,2 ^(k) of the radio wave, the sensor 1 ₂ and the sensor 1 ₃ of a radio wave arrival time difference .DELTA..tau _2,3 to the equations using ^(k), the sensor 1 ₃ and the sensor 1 ₄ of a radio wave arrival time difference .DELTA..tau _{3, 4} equations with ^(k) are those calculated based on. Here, the function g _{n, m} (x, y, z) is defined as in equation (16).

Next, using the function g _{n, m} (x, y, z), a matrix A ^(k) shown in equation (17) is ^obtained .

Here, each component of the matrix A ^(k) is obtained using the target provisional positions [x ′ ^(k) , y ′ ^(k) , z ′ ^(k) ] output from the provisional positioning unit 34. An example is shown in equation (18).

Finally, a matrix W ^(k) shown in Equation (19) is ^obtained .
W ^(k) = (A ^{(k) H.A (k)} ) ^-1 (19)
Here, A ^{(k) H} represents the complex conjugate transpose of the matrix A ^(k) , and (A ^{(k) H} · A ^(k) ) ⁻¹ represents the matrix (A ^{(k) H} · A ^(k) ). Represents the inverse matrix of.
The weighting coefficient φ ^(k) is calculated based on the diagonal component of the matrix W ^(k) as shown in the equation (20).

Note (20) In the formula, three elements of the diagonal elements of the weighting factor phi ^(k) the matrix ^{W (k) (W (k} ) (1,1), W (k) (2,2), W ( ^{k) The} calculation is performed using (3, 3)), but one calculated using only one or two elements may be used.

The weighting processing unit 362 weights the mismatch time ε ′ _{n, m} ^(k) calculated by the mismatch time calculating unit 35 using the weighting coefficient φ ^(k) obtained by the equation (20) and the like (21 ) Calculate and output the temporary clock error ε ″ _{n, m} .

  The positioning process control unit 37 subtracts the provisional clock error calculated by the provisional clock error calculation unit 36 from the arrival time difference of the radio wave to obtain a correction value, and uses the obtained correction value for correction reception of the radio wave used by the provisional positioning unit 34. Output as time difference. In addition, the positioning process control unit 37 completes a series of positioning processes by the provisional positioning unit, the mismatch time calculation unit, and the provisional clock error calculation unit according to the determination criteria in the process of calculating the correction value of the arrival time difference, The target provisional position and provisional clock error obtained in each process are output as the final target position and clock error, or a series of positioning processes are continuously performed again to perform the positioning process again.

The positioning processing control unit 37, the arrival time difference .DELTA..tau _n of radio _waves, in order to correct the _m ^{(k), (22)} as shown in equation TDOA .DELTA..tau _n radio _{waves, m} ^(k) Provisional clock error from epsilon '_'n, subtracts the _m, radio waves corrected arrival time difference Δτ' _{n, m} ^{(k) is} determined. The corrected arrival time difference of the radio wave is used by the temporary positioning unit 34 to calculate the target temporary position at each time as described above.
Δτ ′ _{n, m} ^(k) = Δτ _{n, m} ^(k) −ε ″ _{n, m} (1 ≦ k ≦ K) (22)

Further, the positioning processing control unit 37 includes a processing number counting unit 371 as shown in FIG. 6 in order to determine whether or not the positioning processing is continued. The processing count counting unit 371 counts the number of times a series of processing has been performed by the temporary positioning unit 34, the mismatch time calculation unit 35, and the provisional clock error calculation unit 36, and the count number reaches a preset value (determination criterion). In such a case, it is determined that a series of positioning processes is completed. At this time, the positioning process control unit 37 determines the target provisional position [x ′ ^(k) , y ′ ^(k) z ′ ^(k) ] output from the temporary positioning unit 34 in the last process as the target to be obtained. The temporary clock error ε ″ _{n, m} output from the temporary clock error calculation unit 36 in the last process is output as the clock error of the sensors 1 _n and 1 _m .

  On the other hand, when the processing number counting unit 371 does not reach the preset value, it is determined that the series of positioning processing is to be continued again, and the positioning processing control unit 37 calculates the equation (22). To correct the arrival time difference, output the corrected arrival time difference of the radio wave to the temporary positioning unit 34, and perform a series of positioning processes again.

  Further, the positioning processing control unit 37 may include a residual processing unit 372 as shown in FIG. In this case, the residual processing unit 372 calculates a difference (residual) between the target provisional position obtained in the current process and the target provisional position obtained in the previous process, and this residual is set in advance. If it is smaller than the measured value (determination criterion), it is determined that a series of positioning processes are completed.

  At this time, the positioning process control unit 37 outputs the target temporary position and the temporary clock error obtained in the current process as the target position and the clock error to be obtained. On the other hand, in the residual processing unit 372, when the residual is larger than a preset value, it is determined that the series of positioning processing is to be continued again, and the positioning processing control unit 37 arrives according to the equation (22). The time difference is corrected, the corrected arrival time difference of the radio wave is output to the temporary positioning unit 34, and a series of positioning processes is performed again.

  Further, the continuation or completion of a series of positioning processes may be determined based on the residual of the temporary clock error obtained by the temporary clock error calculation unit 36, or the temporary clock error residual and the target provisional You may make it carry out using both of the residual of a position.

  Further, the positioning processing control unit 37 includes both a processing count counting unit 371 and a residual processing unit 372, and combines a series of positioning processing and a residual of a target position or a residual of a clock error by combining a series of positioning processing. It may be determined whether processing is continued or completed.

  As described above, according to the second embodiment, the positioning unit 3 uses the provisional positioning unit 34 to calculate the distance obtained by multiplying the corrected arrival time difference of radio waves between sensors by the speed of radio waves. Are created for each reception time of radio waves, and by calculating these equations for each reception time, the provisional position of the target at each time is calculated, and the mismatch time calculation unit 35 The time obtained by dividing the difference between the target provisional position and the distance of each sensor by the speed of the radio wave is subtracted from the difference in the arrival time of the radio wave between the sensors, and is calculated as a mismatch time at each time. The calculation unit 36 calculates a provisional clock error between the sensors based on the calculated mismatch time, and the positioning processing control unit 37 calculates the provisional clock error calculated by the provisional clock error calculation unit 36 from the arrival time difference of radio waves. The The corrected arrival time difference of the radio wave is calculated and output to the provisional positioning unit 34, and a series of positioning processes are completed according to the determination criteria, and the target provisional position and provisional clock error obtained in each process are finally obtained. The target position and clock error are output, or a series of positioning processes are controlled to continue again. Therefore, it is possible to correct the clock error between the sensors in the positioning device, and the same effect as in the first embodiment can be obtained.

  In the first embodiment and the second embodiment, the case where the sensor is fixed has been described as an example. However, even when the sensor moves, if the position is known, the expressions (5), (11), ( 13) Since the remaining number of the equation does not increase, the clock error between the target position and the sensor can be calculated.

Embodiment 3 FIG.
In the first embodiment and the second embodiment, the method of calculating the position of the target by moving a single target whose position is to be known as time passes and observing the target multiple times has been described. However, a feature of the present invention is that the radio wave from the target existing at different positions is observed, and the clock error between the target position and the sensor is calculated based on the arrival time difference obtained therefrom. Therefore, when there are multiple targets at different positions, radio waves from each target are received once by each sensor, and based on the arrival time difference of each target obtained therefrom, the clock between each target position and the sensor is It is also possible to calculate the error.

FIG. 8 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 3 of the present invention. In the figure, 7 _{1 to} 7 _J are a plurality of targets whose positions are to be known, and J is the total number of targets. A plurality of sensors 4 ₁ to 4 _N are emitted from the target 7 ₁ to _7-J, or a means for receiving the radio wave reflected by the target 7 ₁ to _7-J. The multiple arrival time difference calculation unit 5 is a means for calculating the arrival time difference of radio waves received by each sensor. Multiple positioning unit 6, based on the arrival time difference of the radio wave between the sensor, a means for calculating the clock error and the position of each target 7 ₁ to _7-J between the sensors. The multiple positioning unit 6 includes a multiple batch positioning unit 61. The multiple batch positioning unit 61 uses an equation that assumes that the distance obtained by multiplying the time of radio wave by the time obtained by subtracting the clock error between sensors from the difference in radio wave arrival time is equal to the difference in radio wave propagation distance. It is a means for measuring the clock error between sensors and the positions of the respective targets 7 _{1 to} 7 _J by creating them and making them simultaneous.

Next, the principle of the present invention will be described. When the sensors 4 ₁ to 4 _N receive radio waves radiated from the targets 7 _{1 to} 7 _J or reflected by the targets 7 _{1 to} 7 _J , each sensor observes the arrival time when the radio waves are received. The method is the same as the method described in the first embodiment. Here, as a result of observing the radio wave from the target 7 _j with the sensor 4 _n , it is assumed that the arrival time can be observed as τ _n ^(j) .

The multiple arrival time difference calculation unit 5 calculates the arrival time difference of the radio waves from the targets 7 _{1 to} 7 _J received by the sensors 4 ₁ to 4 _N. Now, as a result of observing the radio wave from the target 7 _j, it is assumed that the arrival time is τ _n ^{(j) at} the sensor _{n and} τ _m ^(j) is the arrival time at the sensor m. In this case, the multiple arrival time calculation unit 5 calculates the arrival time difference Δτ _{n, m} ^{(j) in} which the radio wave from the target 7 _j is received by the sensor n and the sensor m according to the equation (23) and outputs it to the multiple positioning unit 6. .
Δτ _{n, m} ^(j) = τ _n ^(j) −τ _m ^(j) (23)

In the multiple positioning unit 6, in the multiple batch positioning unit 61, for each target, based on the arrival time difference Δτ _{n, m} ^(j) (n ≠ m, 1 ≦ j ≦ J) of radio waves output from the multiple arrival time difference calculation unit 5. Equations are generated and the positions of each target are calculated by solving them. A specific processing method will be described.

The arrival time difference Δτ _{n, m} ^(j) obtained by observing the radio wave from the target 7 _j with the sensor 1 _n and the sensor 1 _m includes a clock error. If this clock error is ε _{n, m} (unknown number), (Δτ _{n, m} ^(j) −ε _{n, m} ) is the arrival time difference that does not include the clock error. For this reason, the distance obtained by multiplying (Δτ _{n, m} ^(j) −ε _{n, m} ) by the velocity c of the radio wave is equal to the difference between the distance from the sensor 1 _n to the target 7 _j and the distance from the sensor 1 _m to the target. Become. Therefore, equation (24) is established.

Here, [X _n , Y _n , Z _n ] are the coordinates (known) of the sensor 1 _n , [X _m , Y _m , Z _m ] are the coordinates (known) of the sensor 1 _m , and [x ^(j) y ^{(j )} z ^(j) ] is the target coordinate (unknown). With respect to one target, the above equation holds as the number of sensors minus one. Therefore, if the total number of sensors is N, (N-1) equations are established. In addition, the total number of targets to be measured is J, and (N-1) equations such as the equation (24) are established for each target, and thus (N-1) × J equations are established in total.

On the other hand, the unknowns in equation (24) include those relating to the position of the target 7 _j [x ^(j) , y ^(j) , z ^(j) ] and those relating to the clock error ε _{n, m} . Among these, the unknowns [x ^(j) , y ^(j) , z ^(j) ] of target positions are 3 × J because they differ for each target. Further, the clock error ε _{n, m} between the sensors is (N−1). Therefore, the total number of unknowns included in (N−1) × J equations is ((N−1) + 3J). Therefore, when the condition of the equation (25) is satisfied, the unknown and the equation are equal, and the unknown can be determined. However, since the arrival time difference may include an observation error, the equation (24) does not always intersect at one point. In this case, the unknown is calculated by obtaining a least squares solution.
(N−1) × J = (N−1) + 3J (25)
For example, when the number N of sensors is 5, the target total number J is 4, and an unknown number can be determined. If there are more equations than unknowns, the least squares solution is obtained to calculate the unknowns.

  The multiple batch positioning unit 61 calculates unknowns (target position and clock error) as described above.

  As described above, according to the third embodiment, based on the arrival time difference of radio waves between the sensors calculated by the plurality of arrival time difference calculation units 5, a plurality of positioning units for positioning the clock error between the sensors and each target position. In particular, in the multiple positioning unit 6, the distance obtained by multiplying the time obtained by subtracting the clock error between the sensors from the difference in radio wave arrival time between the sensors in the multiple positioning unit 61, Equations that are equal to the difference in radio wave propagation distance are created for each target, and these equations are combined to calculate the clock error between sensors and the position of each target. Therefore, it is possible to correct a clock error between sensors in the positioning device. Therefore, there is no need to synchronize between sensors, there is no need to consider cable connection for synchronizing sensors in accordance with sensor placement, sensor movement, etc., and to correct clock errors There is no need to install a separate transmitter station.

Embodiment 4 FIG.
FIG. 9 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 4 of the present invention. In the figure, portions corresponding to those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted in principle. The multiple positioning unit 6 according to the fourth embodiment includes a multiple provisional positioning unit 64, a multiple mismatch time calculation unit 65, a multiple provisional clock error calculation unit 66, and a multiple positioning process control unit 67.

Multiple provisional positioning unit 64, a radio wave correction TDOA Δτ output from a plurality positioning processing control unit 67 _'n, with _m ^{(j), (26)} the provisional position of the target 7 _j [x by equation' ^{(j )} , Y ′ ^(j) , z ′ ^(j) ].

When there is no corrected arrival time difference Δτ ′ _{n, m} ^{(j) of} the radio wave output from the multiple positioning processing control unit 67, the arrival time difference Δτ _{n, m} ^(j) itself output from the multiple arrival time difference calculation unit 5. Instead of the corrected radio wave arrival time difference Δτ ′ _{n, m} ^(j) , the target provisional position is calculated.

Unlike the formula (24) of the multiple batch positioning unit 61 of the third embodiment, the multiple temporary positioning unit 64 calculates a temporary target position that ignores the clock error. Since the unknown in equation (26) is only the provisional position [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ] of each target, if three or more equations like equation (26) hold The provisional position can be calculated. Since the positioning equation (26) is established with the number of sensors minus one, when the number of sensors N is 4 or more, the target provisional position can be calculated. However, since the radio wave arrival time difference Δτ ′ _{n, m} ^(j) includes a clock error, the positioning equation (26) does not always intersect at one point. In that case, the target provisional position is calculated so as to obtain a least squares solution. Even when there are more equations than unknowns, the provisional position of each target is calculated so as to obtain a least squares solution.

  The multiple provisional position measurement unit 64 obtains the provisional position of each target as described above, and outputs it to the multiple mismatch time calculation unit 65.

In the multiple mismatch time calculation unit 65, the time obtained by dividing the difference between the provisional position of each target obtained by the multiple provisional position positioning unit 64 and the distance of each sensor by the velocity of the radio wave is used as the arrival of radio waves between the sensors. Subtract from the time difference to calculate the mismatch time for each target. This process is expressed by equation (27). The difference between the “distance between each target provisional position and the sensor 1 _n ” and the “distance between each target provisional position and the sensor 1 _m ” output from the plurality of provisional positioning units 64 is obtained. Next, the time (the second term of the equation) is obtained by dividing the difference between the target temporary position and the distance of each sensor by the radio wave velocity c. The obtained time (the second term of the equation) is subtracted from the arrival time difference Δτ _{n, m} ^{(j) of} the radio waves output from the plurality of arrival time difference calculation units 2 to obtain a mismatch time ε ′ _{n, m} ^(j) . .

  The multiple mismatch time calculation unit 65 outputs the mismatch time calculated as described above to the multiple temporary clock error calculation unit 66.

The mismatch time ε ′ _{n, m} ^(j) is due to the clock error between sensors. Therefore, the multiple provisional clock error calculation unit 66 calculates a provisional clock error based on the mismatch time of each target. The multiple provisional clock error calculation unit 66 includes a multiple average processing unit 661 as shown in FIG. The multiple average processing unit 661 obtains an average value for the mismatch time ε ′ _{n, m} ^(j) (1 ≦ j ≦ J) between the sensor 1 _n and the sensor 1 _m as shown in the equation (28), and this is calculated as the sensor. _Let tentative clock error ε ″ _{n, m} for 1 _n and sensor 1 _m .

Further, the multiple provisional clock error calculation unit 66 may include a multiple weighting processing unit 662 as shown in FIG. In this case, the multiple weighting processing unit 662 performs weighting by multiplying the mismatch time ε ′ _{n, m} ^(j) output from the multiple mismatch time calculation unit 65 by a weighting coefficient φ ^(j) described later, and between the sensors. The provisional clock error ε ″ _{n, m} is calculated.

As the weighting coefficient φ ^(j) , the rate of decrease in estimation accuracy of the target position obtained from the geometric relationship between the target position and the sensor position described in the first embodiment (geometric low accuracy decrease rate: GDOP). Etc. can be used.

Now, it is assumed that the number N of sensors is 4, and the provisional position of each target calculated by the plurality of provisional positioning units 64 is [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ]. Then, the provisional position of the target, the sensor 1 ₁ and the sensor 1 ₂ and equations using the arrival time difference Δτ _1,2 ^(j) of the radio wave, the sensor 1 ₂ and the sensor 1 ₃ of a radio wave arrival time difference .DELTA..tau _2,3 to the equations using ^(j), the sensor 1 ₃ and the sensor 1 ₄ of a radio wave arrival time difference .DELTA..tau _{3, 4} equations with ^(j) those which are calculated based on.
First, using the function g _{n, m} defined in Equation (16), a matrix B ^(j) shown in Equation (29 ⁾ is obtained.

Here, each component of the matrix B ^(j) is obtained using the provisional position [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ] of each target output from the plurality of provisional positioning units 64. . An example is shown in equation (30).

Finally, a matrix U ^(j) shown in Equation (31 ⁾ is obtained.
U ^(j) = (B ^{(j) H} · B ^(j) ) ^-1 (31)
The weighting coefficient φ ^(j) is calculated based on the diagonal component of the matrix U ^(j) as shown in equation (32).

In Equation (32), the weighting coefficient φ ^(j) is expressed by three elements (U ^(j) (1,1), U ^(j) (2,2), U ^{( j)} of the matrix U ^(j) . ^{j) Although} it is calculated using (3, 3)), it is also possible to use one calculated with only one or two elements.

The multiple weighting processing unit 662 weights the mismatch time ε ′ _{n, m} ^(j) calculated by the multiple mismatch time calculating unit 65 using the weighting coefficient φ ^(j) obtained by the equation (32) or the like, The provisional clock error ε ″ _{n, m} is calculated and output by equation (33).

  The multiple positioning processing control unit 67 obtains a correction value by subtracting the temporary clock error calculated by the multiple temporary clock error calculation unit 66 from the arrival time difference of the radio waves, and uses the obtained correction value in the multiple temporary positioning unit 64. Is output as the corrected arrival time difference. Further, in the process of calculating the arrival time difference correction value, the multiple positioning processing control unit 67 performs a series of positioning processes by the multiple temporary positioning unit, the multiple mismatch time calculating unit, and the multiple temporary clock error calculating unit according to a determination criterion. And then output the provisional position and the temporary clock error of each target obtained in each process as the final position and clock error of each target, or continue the positioning process again and perform the positioning process. Control to start over.

In order to correct the arrival time difference Δτ _{n, m} ^(j) of the radio wave, the multiple positioning processing control unit 67 calculates the provisional clock error ε from the arrival time difference Δτ _{n, m} ^(j) of the radio wave as shown in the equation (34). '' _n, it subtracts the _m, radio wave correction TDOA .DELTA..tau _'n, determine the _m ^(j). The corrected arrival time difference of the radio wave is used for calculating the target provisional position at each time by the plurality of provisional positioning units 64 as described above.
Δτ ′ _{n, m} ^(j) = Δτ _{n, m} ^(j) −ε ″ _{n, m} (1 ≦ j ≦ J) (34)

  Further, the multiple positioning processing control unit 67 includes a multiple processing number counting unit 671 as shown in FIG. 12 in order to determine whether the positioning processing is continued or completed. The multiple processing number counting unit 671 counts the number of times a series of processing has been performed by the multiple provisional positioning unit 64, the multiple mismatch time calculation unit 65, and the multiple provisional clock error calculation unit 66, and the count number is a preset value (determination When the reference is reached, it is determined that a series of positioning processes is completed.

At this time, the multiple positioning processing control unit 67 obtains the temporary position [x ′ ^(j) , y ′ ^(j) z ′ ^(j) ] of each target output from the multiple temporary positioning unit 64 in the last process. The position of each target is output, and the provisional clock error ε ″ _{n, m} output from the plurality of provisional clock error calculation units 66 in the last process is output as the clock error of the sensors 1 _n and 1 _m . On the other hand, when the number of counts in the multiple processing count unit 671 has not reached the preset value, it is determined that the series of positioning processing is to be continued again, and the multiple positioning processing control unit 67 (34) ) To correct the arrival time difference and output the corrected arrival time difference of the radio wave to the plurality of provisional positioning units 64 to perform a series of positioning processes again.

  Further, the multiple positioning processing control unit 67 may include a multiple residual processing unit 672 as shown in FIG. In this case, the multiple residual processing unit 672 calculates a difference (residual) between the target provisional position obtained in the current process and the target provisional position obtained in the previous process. When it is smaller than the set value (judgment criterion), it is determined that a series of positioning processes is completed.

  At this time, the multiple positioning processing control unit 67 outputs the target provisional position and provisional clock error obtained in the current processing as the position and clock error of each target to be obtained. On the other hand, in the multiple residual processing unit 672, when the residual is larger than a preset value, it is determined that the series of positioning processing is to be continued again, and the multiple positioning processing control unit 67 performs the equation (34). Thus, the arrival time difference is corrected, and the corrected arrival time difference of the radio wave is output to the plurality of provisional positioning units 64, and a series of positioning processes is performed again.

  Further, the continuation or completion of a series of positioning processes may be determined based on the residuals of the provisional clock errors obtained by the plurality of provisional clock error calculation units 66, or the residuals of the provisional clock errors and the target You may make it carry out using both the residuals of a temporary position.

  Further, the multiple positioning processing control unit 67 includes both a multiple processing number counting unit 671 and a multiple residual processing unit 672, and combines a series of positioning processing counts with a target position residual or a clock error residual. It may be determined whether to continue or complete a series of positioning processes.

  As described above, according to the fourth embodiment, in the multiple positioning unit 6, the distance obtained by multiplying the corrected arrival time difference of the radio wave between the input sensors by the radio wave speed by the multiple temporary positioning unit 64. An equality equal to the difference in radio wave propagation distance is created for each target, and the provisional position of each target is calculated by solving these equations for each target. The time obtained by dividing the difference between the provisional position and the distance of each sensor by the speed of the radio wave is subtracted from the difference in the arrival time of the radio wave between the sensors, and is calculated as a mismatch time at each target. 66, a temporary clock error between the sensors is calculated based on the calculated mismatch time, and the multiple positioning processing control unit 67 calculates the temporary clock error calculated by the multiple temporary clock error calculation unit 66 from the arrival time difference of radio waves. Are subtracted to obtain the corrected arrival time difference of the radio wave and output to the plurality of provisional positioning units 64, and a series of positioning processes are completed in accordance with the determination standard, and the provisional position and provisional clock error of each target obtained in each process are obtained. Is output as the final target position and clock error, or a series of positioning processes are continuously performed again. Therefore, it is possible to correct the clock error between the sensors in the positioning device, and the same effect as in the third embodiment can be obtained.

  In the first embodiment and the second embodiment, the method of calculating the position of the target and the clock error at each observation time using the movement of one target has been described. In the third and fourth embodiments, the method of calculating the position of each target and the clock error using the presence of a plurality of targets has been described. Therefore, it is possible to calculate the position and clock error of each target at each observation time by using the combination of the two methods and using the existence and movement of a plurality of targets.

Embodiment 5. FIG.
In the first to fourth embodiments, a method has been described in which radio waves reflected or radiated from a target are received by a plurality of sensors and a target position is calculated using a difference in arrival times of the received radio waves. However, it is also possible to reverse the transmission / reception direction of radio waves, observe radio waves at the target, and calculate the target position using the radio wave observation results at the target. Therefore, Embodiment 5 shows an example in which the present invention is applied when the target position is calculated using the reception time of the radio wave at the target.

  In the following description, a mobile communication system such as a mobile phone is assumed as a specific example of a target for obtaining a position according to the present invention, and the target is called a mobile terminal. As a specific example of the sensor, a base station device used in a mobile communication network is assumed.

  A base station apparatus in a mobile communication system already in practical use has a function of transmitting a radio signal to a mobile terminal (transmitting station function) and a function of receiving a radio signal from the mobile terminal (receiving station function). However, here, the transmitting station and the receiving station will be described as separate units by focusing on the functional aspects of the base station apparatus. However, there is no problem even if the transmitting station and the receiving station are integrated.

FIG. 14 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 5 of the present invention. In the figure, transmitting stations 8 ₁ to 8 _N radiate radio waves to mobile terminals 10 ₁ to 10 _J , and transmit radio wave radiating time, which is time when radio waves are radiated, to base station controller 15. . Here, N is the total number of transmitting stations, and J is the total number of mobile terminals.

The mobile terminals 10 ₁ to 10 _J observe the radio wave arrival time when the radio wave radiated from the transmission station is received, transmit the received radio wave to the reception station 9, and information that can identify which transmission station the received radio wave belongs to This is means for transmitting (transmitting station information) to the receiving station 9.

  The receiving station 9 is means for receiving the radio wave arrival time and transmitting station information transmitted from the mobile terminal and transmitting them to the base station control device 15.

The base station control device 15 uses the radio wave arrival time and the transmitting station information transmitted from the receiving station 9 and the radio wave radiation time transmitted from the transmitting station 8 _n (1 ≦ n ≦ N) to set the clock between the transmitting stations. Means for calculating the error and the position of each mobile terminal. The base station control device 15 also includes a propagation time difference calculation unit 13 and a positioning unit 11.

The propagation time difference calculation unit 13 is based on the radio wave arrival time and the transmission station information transmitted from the reception station 9 and the radio wave emission time transmitted from the transmission station 8 _n (1 ≦ n ≦ N). It is a means for obtaining a propagation time that is a difference in radiation time and further obtaining a propagation time difference that is a difference in propagation time.

  The positioning unit 11 is means for calculating a clock error between the transmitting stations and a position of each mobile terminal based on the propagation time difference between the transmitting stations.

Next, the operation of the positioning apparatus according to Embodiment 5 of the present invention will be described. The transmitting stations 8 ₁ to 8 _N radiate radio waves to the mobile terminals 10 ₁ to 10 _J when the clocks held in the respective stations indicate predetermined times, and set the radio wave radiating time to the base station controller. 15 is notified.

In the following description, it is assumed that each of the transmitting stations 8 ₁ to 8 _N radiates radio waves when the clock in the own station indicates time t (same time). Also, the clocks held by the transmitting stations 8 ₁ to 8 _N in their own stations have their own clock errors (which may be different for each of the transmitting stations 8 ₁ to 8 _N ) because they are not time-synchronized. is doing.

Here, the time that does not include any clock error is referred to as “standard time”, and the clock error with respect to the standard time generated in the local clock of the transmitting station 8 _n (1 ≦ n ≦ N) is _expressed as ε _n (ε _n Only later than the standard time). That is, in the standard time radio emission time of the transmission station 8 _n is expressed as t + ε _n.

The mobile terminal 10 _j (1 ≦ j ≦ J) receives a radio wave radiated by any of the transmission stations 8 ₁ to 8 _N , observes the reception time (radio wave arrival time) and the transmission station information, and observes it. The received radio wave arrival time and the transmitting station information that transmitted the radio wave are transmitted to the receiving station 9.

  Here, as a method of observing the radio wave arrival time and the transmitting station information, for example, the signal waveform of the radio wave radiated from the transmitting station is stored, and the stored signal waveform (reference signal) and the received signal are correlated. There is a way to do so. The degree of correlation between the reference signal and the received signal is expressed by a numerical value (for example, a distance value), and the time when this numerical value satisfies a predetermined condition is estimated as the radio wave arrival time. The predetermined condition here may correspond to, for example, a condition indicating whether or not a numerical value indicating the degree of correlation is equal to or greater than a predetermined value. In this way, the transmitting station is identified based on the reference signal such that the numerical value indicating the degree of correlation is equal to or greater than a predetermined value, and the identified transmitting station is used as transmitting station information.

  Note that it is not necessary for the mobile terminal to sample and store the signal waveforms of all transmitting stations, and it is sufficient to store only the feature values necessary for determining the correlation of the signal waveforms of the transmitting stations. is there.

In this way, the radio wave arrival time of the transmitting station 8 _n (1 ≦ n ≦ N) observed at the mobile terminal 10 _j (1 ≦ j ≦ J) is defined as T _n ^(j) . The true value of the propagation time required for the radio wave to reach the mobile terminal 10 _j from the transmitting station 8 _n is τ ′ _n ^(j), and the clock error occurring in the clock of the mobile terminal 10 _j is ξ ^(j) . Then, the radio wave arrival time T _n ^(j) at the mobile terminal 10 _j is expressed by the equation (35).
T _n ^(j) = t + ε _n + τ ′ _n ^(j) + ξ ^(j) (35)

The mobile terminal 10 _j (1 ≦ j ≦ J) transmits the radio wave arrival time T _n ^(j) (1 ≦ n ≦ N, 1 ≦ j ≦ J) from the transmission station 8 _n and the transmission station that has transmitted this radio wave. 8 Information for identifying _n (transmitting station information) is notified to the receiving station 9.

The receiving station 9 receives the radio wave arrival time T _n ^(j) (1 ≦ n ≦ N, 1 ≦ j ≦ J) and the transmitting station information transmitted from the mobile terminal 10 _j (1 ≦ j ≦ J), The radio wave arrival time T _n ^(j) and transmitting station information are transmitted to the base station controller 15.

The base station controller 15, the propagation time difference calculator 13, the radio wave arrival time of the transmission station _{8 n} obtained from the reception station 9 _T ^{n (j),} from the radio emission time t obtained from the transmitting station _{8 n,} (36 ) To obtain the time (propagation time τ _n ^(j) ) required until the radio wave propagates from the transmitting station 8 _n to the mobile terminal 10 _j .
τ _n ^(j) = T _n ^(j) −t (1 ≦ n ≦ N, 1 ≦ j ≦ J) (36)

Next, the mobile terminal 10 _j propagation time between the transmission station _{8 n} τ _n ^(j), transmitting station _{8 m (m ≠ n, 1} ≦ m ≦ N) and the mobile terminal 10 _j propagation time τ _m ^(j) Based on the above, the difference Δτ _{n, m} ^(j) between the two propagation times is calculated by the equation (37).
Δτ _{n, m} ^(j) = τ _n ^(j) −τ _m ^(j) (37)

Note that the propagation time difference Δτ _{n, m} ^(j) (1 ≦ n ≦ N, 1 ≦ j ≦ J) is “the time required for the radio wave radiated from the transmitting station 8 _n to be received by the mobile terminal 10 _j. ”And“ time required for the radio wave radiated from the transmitting station 8 _m to be received by the mobile terminal 10 _j ”, and what is read as the arrival time difference in the first to fourth embodiments, Are the same.

In this way, the propagation time difference calculation unit 13 outputs the calculated propagation time difference Δτ _{n, m} ^(j) to the positioning unit 11.

The positioning unit 11 calculates a clock error between the mobile terminal position and the transmitting station based on the propagation time difference Δτ _{n, m} ^(j) transmitted from the propagation time difference calculating unit 13. A specific processing method for calculating the clock error will be described below.

Substituting Equations (36) and (35) into Equation (37) yields Equation (38).
Δτ _{n, m} ^(j) = τ _n ^(j) −τ _m ^{(j)
_{= T n (j) -t- (}} T m (j) -t)
= T + ε _n + τ ′ _n ^(j) + ξ ^(j) −t− (t + ε _m + τ ′ _m ^(j) + ξ ^(j) −t)
= Τ ' _n ^(j) -τ' _m ^(j) + ε _n -ε _m (38)

As apparent from the equation (38), the propagation time difference Δτ _{n, m} ^(j) transmitted from the propagation time difference calculation unit 13 is a value included in the clock errors ε _n and ε _m between the transmitting stations 8 _n and 8 _m . It is. If the difference (ε _n −ε _m ) of the clock error is removed from Δτ _{n, m} ^(j) , a propagation time difference that does not include the clock error can be obtained.

Therefore, if the clock error (ε _n −ε _m ) between two transmitting stations (transmitting stations 8 _n , 8 _m ) is represented by an unknown ε _{n, m} , (Δτ _{n, m} ^(j) −ε _{n, m} ) is obtained. This is a propagation time difference not including a clock error. The distance obtained by multiplying (Δτ _{n, m} ^(j) −ε _{n, m} ) by the velocity c of the radio wave is “the distance from the transmission station 8 _n to the mobile terminal 10 _j ” and “the transmission station 8 _m to the mobile terminal 10. _It is equal to the difference of “distance to _j ”. Therefore, equation (39) is established.

In equation (39), [X _n , Y _n , Z _n ] are the coordinates of the transmitting station 8 _n and [X _m , Y _m , Z _m ] are the coordinates of the transmitting station 8 _m . Since the coordinates of the transmitting stations 8 _n and 8 _m can be acquired in advance when the transmitting station is installed, they are known amounts here. On the other hand, [x ^(j) , y ^(j) , z ^(j) ] are the coordinates of the mobile terminal 10 _j . Since the mobile terminal 10 _j changes its position from time to time as the user moves, it is an unknown number.

For each of the mobile terminals 10 ₁ to 10 _J , depending on the combination of the transmitting stations (by replacing n and m), the number of equations obtained by subtracting 1 from the number of transmitting stations N is represented by the equation (39). can get. On the other hand, since the total number of mobile terminals is J, (N−1) × J is obtained in total as the equation shown in equation (39).

Whether (N-1) .times.J equations obtained in this way are simultaneous equations will be examined to determine whether all unknowns can be determined. In the equation (39), the position of the mobile terminal is expressed as [x ^(j) , y ^(j) , z ^(j) ], and these x, y, and z coordinates are three independent unknowns. . Since there are three unknowns per mobile terminal, there are 3 × J unknowns for J mobile terminals. The clock error ε _{n, m} between the transmitting stations is also an unknown number, and the number thereof is (N−1).

From the above, the total number of unknowns included in (N−1) × J simultaneous equations is (3 × J + (N−1)). Generally, when at least the number of equations is equal to the number of unknowns (when equation (40) holds), the unknowns can be determined from the simultaneous equations.
(N−1) × J ≧ (N−1) + 3 × J (40)

  For example, if the number of transmitting stations is N = 5 and the number of mobile terminals is J = 4, the equation (40) is satisfied, so that an unknown number can be determined. Even when there are more equations than unknowns, the unknowns are calculated by obtaining a least squares solution. In particular, since the propagation time difference includes various errors, if the number of equations exceeds the number of unknowns, different solutions may be obtained depending on the combination of equations. In such a case, the unknown may be calculated by obtaining a least square solution.

  As described above, according to the fifth embodiment, even if the base station controller 15 includes a clock error between the transmission stations, the number of clock errors between the transmission stations and the position of the mobile terminal The position of the mobile terminal can be measured by solving a sufficient equation for specifying the coordinates.

  In the positioning device according to the fifth embodiment of the present invention, for the purpose of facilitating understanding of the description, a plurality of transmitting stations are configured to radiate radio waves all at once when their own clocks indicate the same time t. It was. However, if the amount of movement of the mobile terminal is sufficiently small compared to the length of radio wave emission time of the transmitting station and the size of the clock error, each transmitting station may radiate radio waves at different times. Will be easily understood. Therefore, the features of the present invention can be applied to cases where a plurality of transmitting stations radiate radio waves at different times.

Embodiment 6 FIG.
The positioning apparatus according to Embodiment 5 combines (N−1) × J equations by combining the positions and radio wave radiation times of N transmitting stations, and the radio wave arrival times and transmitting station information at J mobile terminals. And (N-1) + 3 × J unknowns are collectively determined by treating these equations as simultaneous equations. However, the propagation time difference can be corrected by solving a smaller number of equations a plurality of times. The positioning device according to Embodiment 6 of the present invention has such a feature.

  FIG. 15 is a block diagram showing a detailed configuration of the positioning unit 11 in the positioning device according to the sixth embodiment of the present invention. Other parts are the same as those of the positioning apparatus of the fifth embodiment unless otherwise supplemented.

Also in the positioning device according to the sixth embodiment of the present invention, the propagation time difference calculation unit 13 transmits the propagation time τ _n ^(j) between the transmitting station 8 _n (1 ≦ n ≦ N) and the mobile terminal 10 _j (1 ≦ j ≦ J ^). And the propagation time difference Δτ _{n, m} ^(j) between the transmission station 8 _m (m ≠ n, 1 ≦ m ≦ N) and the propagation time τ _m ^(j) of the mobile terminal 10 _j is output.

The temporary positioning unit 114 is either the corrected propagation time difference Δτ ′ _{n, m} ^(j) calculated by the positioning processing unit 117 by a method described later or the propagation time difference Δτ _{n, m} ^(j) output from the propagation time difference calculating unit 13. Is used to calculate the temporary position [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ] of the mobile terminal 10 _{j according to} the equation (41).

The expression (41) is expressed when the corrected propagation time difference Δτ ′ _{n, m} ^(j) is used. However, when the propagation time difference Δτ _{n, m} ^(j) is used, Δτ ′ _{n, m} ⁽ Replace ^j) with Δτ _{n, m} ^(j) . The case where the propagation time difference Δτ _{n, m} ^(j) is used is a state where the positioning unit 11 is in the initial state and other states, and the effective corrected propagation time difference Δτ ′ _{n, m} ^(j) has not yet been calculated. .

The temporary positioning unit 114 calculates a temporary mobile terminal position ignoring the clock error. Since the unknown in equation (41) is only the provisional position [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ] of each mobile terminal, three or more equations such as equation (41) hold. For example, the provisional position can be calculated. Since the positioning equation (41) can be created (number of usable transmitting stations −1), when the number of transmitting stations N is 4 or more, the number of equations becomes larger than the unknown, A provisional position is calculated.

Since the corrected propagation time difference Δτ ′ _{n, m} ^(j) includes a clock error, the positioning equation (41) does not always intersect at one point, but in this case, a least square solution is obtained. In this way, the provisional position of the mobile terminal is calculated. Also, even when there are more equations than unknowns, the provisional position of each mobile terminal is calculated by obtaining the least square solution.

The mismatch time calculation unit 115 calculates the mismatch time ε ′ _{n, m} ^(j) by the equation (42). The mismatch time is a difference in propagation time caused by a clock error between transmitting stations. First, the difference between the “provisional position of each mobile terminal and the distance between the transmitting stations 8 _n ” and the “distance between the temporary position of each mobile terminal and the transmitting station 8 _m ” output from the temporary positioning unit 114 is obtained. Next, the time (second term on the right side of equation (42)) is obtained by dividing the difference between the provisional position of the mobile terminal and the distance between each transmitting station by the radio wave velocity c. The obtained time (the second term on the right side of the equation (42)) is subtracted from the propagation time difference Δτ _{n, m} ^{(j) of} the radio wave output from the propagation time difference calculation unit 13 to obtain a mismatch time ε ′ _{n, m} ^{(j )} .

  The provisional clock error calculation unit 116 calculates a provisional clock error based on the mismatch time of each mobile terminal calculated by the mismatch time calculation unit 115. As a method of calculating the provisional time error, a method of estimating an average value of mismatch times in a plurality of mobile terminals as a provisional time error, or a weighting factor is set for each mobile terminal, and the mismatch time for each mobile terminal is weighted. Thus, a method for calculating a provisional time error may be used. The specific processing procedure of these methods is shown below.

(Method of estimating average value as provisional time error)
In this method, as shown in the equation (43), an average value is obtained for the mismatch time ε ′ _{n, m} ^(j) (1 ≦ j ≦ J) between the transmitting station 8 _n and the transmitting station 8 _m , and this is obtained. 8 _n and a temporary clock error ε ″ _{n, m} for the transmitting station 8 _m .

(Method of weighting mismatch time for each mobile terminal)
This method performs weighting by multiplying the mismatch time ε ' _{n, m} ^(j) by the weighting coefficient φ ^(j) for each mobile terminal, and calculates it as a temporary clock error ε'' _{n, m} between transmitting stations. Is the way to do.

As the weighting coefficient φ ^(j) , the rate of decrease in estimation accuracy of the mobile terminal location obtained from the geometric relationship between the location of the mobile terminal and the transmission station described in Embodiment 2 (geometric accuracy decrease rate: GDOP) ) Etc. Hereinafter, an example of a method for calculating the weighting coefficient φ ^(j) will be described.

Assume that the number N of transmitting stations is 4, and the temporary position of each mobile terminal calculated by the temporary positioning unit 114 is [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ]. The provisional position of the mobile terminal is calculated by the provisional positioning unit 114. In order to make the description more specific, the provisional positions of these mobile terminals are the equations using the propagation time difference Δτ _1,2 ^(j) between the transmitting station 8 ₁ and the transmitting station 8 ₂ , the transmitting station 8 ₂ and the transmission and equations using the station 8 ₃ transit time .DELTA..tau _2,3 of ^_(j), which has been calculated on the basis of the equation using the transit time .DELTA..tau _{3, 4} of the transmission station 8 ₃ and the transmission station 8 _{4 ^(j)} Suppose there is.

First, the function g _{n, m} is defined by equation (44).

Next _, using the function gn _{, m} defined in Equation (44), a matrix B ^(j) shown in Equation (45 ⁾ is obtained.

Here, each component of the matrix B ^(j) is obtained using the provisional positions [x ′ ^(j) , y ′ ^(j) , z ′ ^(j) ] of each mobile terminal output from the provisional positioning unit 114. . An example is shown in equation (46).

Finally, a matrix U ^(j) shown in Equation (47 ⁾ is obtained.
U ^(j) = (B ^{(j) H} · B ^(j) ) ^-1 (47)
B ^H represents a complex conjugate transpose of the matrix B, and B ⁻¹ represents an inverse matrix of the matrix B. The weighting coefficient φ ^(j) is calculated based on the diagonal component of the matrix U ^(j) as shown in the equation (48).

In equation (48), the weighting coefficient φ ^(j) is expressed by three elements (U ^(j) (1,1), U ^(j) (2,2), U ^{( j)} of the matrix U ^(j) . ^{j) Although} it is calculated using (3, 3)), it may be calculated using only one or two elements.

The previously calculated mismatch time ε ″ _{n, m} ^(j) is weighted using the weighting coefficient φ ^(j) obtained in this way, and the provisional clock error ε ″ _{n, m is expressed} by the equation (49). Is calculated.

  This completes the description of the provisional clock error calculation method in the provisional clock error calculation unit 116.

  Subsequently, the positioning processing control unit 117 obtains a correction value by subtracting the temporary clock error calculated by the temporary clock error calculation unit 116 from the propagation time difference.

  If the predetermined criterion is satisfied, the provisional position and provisional clock error of each mobile terminal obtained in the processes so far are output to the external device (not shown) as the final mobile terminal position and clock error. . On the other hand, when the determination criterion is not satisfied, the obtained correction value is output as a radio wave correction propagation time difference to the temporary positioning unit 114 to repeat the positioning process.

Correcting transit time .DELTA..tau calculated in the positioning processing control unit 117 _{'n, m} ^(j), as shown in equation (50), the propagation time difference .DELTA..tau _n, provisional clock error from ^{_{m (j) ε''n}} , m Is obtained by subtracting
Δτ ′ _{n, m} ^(j) = Δτ _{n, m} ^(j) −ε ″ _{n, m} (1 ≦ j ≦ J) (50)

The corrected propagation time difference Δτ ′ _{n, m} ^(j) obtained by the equation (50) is used as a final clock error or correction of the radio wave input to the temporary positioning unit 114 according to the predetermined determination criterion. It is either used as a propagation time difference. Then, the example of this predetermined determination criterion is shown next.

(Example of criteria 1)
The simplest configuration example of the determination criterion is to determine the end (satisfy the determination criterion) / continuation (does not satisfy the determination criterion) based on the number of times the corrected propagation time difference is calculated. That is, when the number of calculations so far reaches a predetermined number, the measurement is temporarily stopped, the measurement result is output to an external device, and the number of calculations is returned to zero. If the number of calculations so far has not reached the predetermined number, the number is increased by one each time the corrected propagation time difference is calculated, and is output to the temporary positioning unit 114 as the corrected propagation time difference of the radio wave.

(Example 2 of criteria)
Also, the difference (residual) between the provisional position of the mobile terminal obtained in the current process and the provisional position of the mobile terminal obtained in the previous process is calculated, and whether or not this residual is included in a predetermined range. The determination criterion may be determined based on the above. That is, for example, when the residual is smaller than a preset value (judgment criterion), a series of positioning processing is completed, otherwise, it is output to the temporary positioning unit 114 as a radio wave correction propagation time difference and the positioning processing is repeated. It is.

  In addition to the residual of the temporary position of the mobile terminal, there is a method of using a residual of a temporary clock error, or a combination of both may be used.

  Further, determination of the end condition based on the residual and determination of the end condition based on the number of times may be combined. As a combination method, it may be such that it does not end until both the condition based on the residual and the condition based on the number of times are satisfied at the same time, and if either one is satisfied, it ends even if the other is not satisfied, It may be said that.

  As described above, in the positioning device according to the sixth embodiment of the present invention, the conditions necessary for determining the clock error of the transmitting station and the mobile terminal position are not sufficiently satisfied (the number of equations is insufficient). Even in such a case, it is possible to estimate the clock error of the transmitting station and the position of the mobile terminal by repeating the process of tentatively determining the clock error of the transmitting station and the position of the mobile terminal.

  In mobile communication systems such as mobile phones and wireless LAN systems, a sufficient number of transmission stations (base stations) are not always available for measuring mobile terminal positions. Even in such a case, the positioning device according to the sixth embodiment of the present invention enables positioning of the mobile terminal position.

  In the sixth embodiment of the present invention, each transmitting station may radiate radio waves at different times as in the fifth embodiment.

Embodiment 7 FIG.
In Embodiment 5 and Embodiment 6, it is assumed that there are a plurality of mobile terminals in an area covered by a plurality of transmission stations in a superimposed manner, and the position of the transmission station and the radio wave arrival time at each mobile terminal are used. It is characterized in that the position of each mobile terminal is estimated.

  By the way, in the case of a mobile communication system, the mobile terminal changes its position from moment to moment as the user moves. On the other hand, the clock error between transmitting stations does not change in such a short time. Based on this knowledge, if the mobile terminal travel time is sufficiently short compared to the period in which the clock error between the transmitting stations changes, a plurality of radio wave arrival times at different positions are acquired from one mobile terminal. It will be understood that the principle of the present invention can be applied by regarding these radio wave arrival times as radio wave arrival times of a plurality of mobile terminals. The positioning device according to Embodiment 7 of the present invention has such a feature.

  FIG. 16 is a block diagram showing a functional configuration of a positioning apparatus according to Embodiment 7 of the present invention. In this configuration, it is assumed that only one mobile terminal 10 exists. Other components having the same reference numerals as those in FIG. 14 are the same as those in the fifth embodiment except for those specifically described in the description of the seventh embodiment.

Next, the operation of the positioning apparatus according to Embodiment 7 of the present invention will be described. The transmitting stations 8 ₁ to 8 _N radiate radio waves to the mobile terminal a plurality of times. Here, it is assumed that the number of times radio waves are radiated is K, and the time at which the transmitting station radiates radio waves is t _k (1 ≦ k ≦ K).

Transmitting station 8 ₁ to 8 _N emits simultaneously radio waves at time t _k relative to the clock of the own transmission station. However, since the time synchronization is not performed between the transmitting stations 8 ₁ to 8 _N, there is a difference corresponding to a clock error in the radio wave emission time of each transmitting station. If the clock error of the transmitting station 8 _n (1 ≦ n ≦ N) is ε _n at the standard time t ₁ , the standard time at which the transmitting station 8 _n radiates radio waves is t ₁ + ε _n .

Here, it is assumed that the variation of the clock error is performed sufficiently gently so as to be negligible with respect to the moving speed of the mobile terminal. If the time t _K -t ₁ during which the transmitting station radiates radio waves is short, the clock error of the transmitting station 8 _n (1 ≦ n ≦ N) at time t _K is equal to the clock error ε _{n at} time t ₁ . . Therefore, in the following, in order to discuss between times t _{1 to} t _K , the clock error of the transmitting station 8 _n is assumed to be ε _n (constant).

By the way, the transmitting stations 8 ₁ to 8 _N also have a role of transmitting the radio wave radiation time during which radio waves are radiated to the base station controller 15. For reference this radio emission time is clocks of each transmission station, the transmission station 8 _n to standard time t _{k +} epsilon _n although a can radiate radio wave transmitting station 8 _n is transmitted to the base station controller 15 radio emission time remains t _k.

The mobile terminal 10 observes the radio wave arrival time when receiving radio waves radiated from the transmission stations 8 ₁ to 8 _N and the transmission station information, and transmits the observed radio wave arrival time and transmission station information to the reception station 9. Since the method of specifying the radio wave arrival time and the transmitting station in the mobile terminal 10 has already been described in the fifth embodiment, a description thereof will be omitted.

It is assumed that the mobile terminal 10 observes the arrival time of radio waves radiated from the transmitting station 8 _n (1 ≦ n ≦ N) at time t _k as T _n ^(k) . Τ ′ _n ^(k) is the true value of the propagation time required for radio waves to reach the mobile terminal 10 from the transmitting station 8 _n, and ξ is the clock error of the mobile terminal 10 that is the difference between the clock of the mobile terminal 10 and the standard time. Then, since the standard time when the radio wave is radiated is t _k + ε _n , the radio wave arrival time T _n ^(k) is expressed by equation (51).
T _n ^(k) = t _k + ε _n + τ ′ _n ^(k) + ξ (51)

In the mobile terminal 10, the radio wave arrival time T _n ^(k) (1 ≦ n ≦ N, 1 ≦ k ≦ K) and the radio wave arrival time T _n ^(k) are radio waves from the transmission station 8 _n. Information is transmitted to the receiving station 9.

The base station controller 15, the propagation time difference calculating portion 13 first radio wave arrival time of the transmission station 8 _n transmitted from the receiving station 9 T _{n ^(k),} is transmitted from the transmitting station 8 _n radio wave radiation time t _k Based on the above, the propagation time τ _n ^(k) , which is the time required for the radio wave to propagate from the transmitting station 8 _n to the mobile terminal 10 at the time t _k , is calculated by the equation (52).
τ _n ^(k) = T _n ^(k) −t _k (52)

At the same time, the propagation time difference calculation unit 13 determines the propagation time τ _n ^(k) between the transmission station 8 _n and the mobile terminal 10, the transmission station 8 _m (m ≠ n, 1 ≦ m ≦ N), and the propagation time between the mobile terminals 10. The propagation time difference Δτ _{n, m} ^(k) _, which is the difference in τ _m ^(k) , is calculated by the equation (53).
Δτ _{n, m} ^(k) = τ _n ^(k) −τ _m ^(k) (53)

Finally, the propagation time difference Δτ _{n, m} ^(k) obtained as described above is output to the positioning unit 11.

Thereafter, the positioning unit 11 measures the mobile terminal position in the same manner as in the fifth embodiment. In calculating the mobile terminal position, the calculation formula of the positioning unit 11 in the fifth embodiment (below formula (39)) is used to calculate the positions [x ^(j) , y ^(j) , z ^(j) ] of a plurality of mobile terminals. It will be easily understood that the processing may be performed by replacing [x ^(k) , y ^(k) , z ^(k) ] in ^k .

  As is clear from the above, according to the positioning apparatus according to the seventh embodiment of the present invention, even when there is only one mobile terminal in the area covered by the transmitting station, this mobile terminal If the mobile terminal moves together, the position of the mobile terminal can be estimated by using the radio wave arrival times at different times in the mobile terminal.

In the description of the positioning apparatus according to the seventh embodiment of the present invention, the number of mobile terminals is 1, but it is not necessarily limited to this. When the equation (40) is modified, the following equation (54) is obtained for the number J of mobile terminals.

  According to this condition, for example, when N = 5, J is required to be 4 or more. However, it will be easily understood that the effect of the positioning device according to the seventh embodiment of the present invention is exhibited even when there are only a number of mobile terminals that do not satisfy this condition.

  In the positioning device according to the seventh embodiment of the present invention, each transmitting station radiates radio waves a plurality of times, but it is not necessary to make the radio wave radiating time the same as other transmitting stations. That is, even if the radio wave emission time is different between the transmitting stations, the influence of the radio wave emission time shift can be ignored if the mobile terminal moves sufficiently gently during that time.

Embodiment 8 FIG.
The positioning unit 11 of the positioning device according to the seventh embodiment includes a motion model assumed in advance according to the movement method of the mobile terminal that is the target of the positioning processing, and performs the positioning processing based on this motion model. You may do it. The motion model predefines the relationship between the position of the mobile terminal and time. For example, using information such as whether the movement of the mobile terminal is constant velocity linear motion or constant acceleration linear motion, Used to predict the positional relationship between different times.

  By introducing such a motion model, the scope of application of the present invention can be further expanded. Specifically, the number of radio wave emissions from the transmitting station can be reduced, and the position of the mobile terminal can be estimated in a short time.

Hereinafter, a case where the mobile terminal is performing a uniform linear motion as an exercise model will be described as an example. In the case of constant-velocity linear motion, the mobile terminal position [x ^(k) , y ^(k) , z ^(k) ] at time t _k can be expressed as in equations (55) to (58).
x ^(k) = x ⁽¹⁾ + v _x · Δt _k (55)
y ^(k) = y ⁽¹⁾ + v _y · Δt _k (56)
z ^(k) = z ⁽¹⁾ + v _z · Δt _k (57)
Δt _k = t _k −t ₁ (58)

Here, [x ⁽¹⁾ , y ⁽¹⁾ , z ⁽¹⁾ ] are the coordinates (unknown) of the mobile terminal at time t ₁ , v _x is the speed (unknown) of the mobile terminal in the x-axis direction, and v _y Is the speed of the mobile terminal in the y-axis direction (unknown), and v _z is the speed of the mobile terminal in the z-axis direction. An equation created by the motion model positioning unit 123 is obtained by substituting this into the equation (39) as shown in equation (59).

These equations are obtained as (N−1) × K. On the other hand, the unknowns are the position [x ⁽¹⁾ , y ⁽¹⁾ , z ⁽¹⁾ ] of the mobile terminal at time t _1, the speed [v _x , v _y , v _z ] of the mobile terminal, and the clock error between the transmitting stations. ε _{n, m} The number of unknowns related to the position of the mobile terminal (the position of the observation time t ₁ and the speed of the mobile terminal) is a constant value 6 regardless of the number of observations K 1, and the number of clock errors between transmitting stations is (N−1). It becomes. Therefore, the condition for obtaining an equation equal to or greater than the number of unknowns is given by equation (60).
(N−1) × K ≧ (N−1) +6 (60)

  However, since the propagation time difference may include an observation error, the equation (59) does not always intersect at one point. In this case, the unknown is calculated by obtaining a least square solution. Even when there are more equations than unknowns, the unknowns are calculated by solving the least squares solution.

  For example, when the number of transmitting stations N is 5, K ≧ 5/2, so that the unknown can be estimated even when the number of observations K = 3. In Embodiment 7 of the present invention, when N = 5, K ≧ 4, so that the mobile terminal position can be calculated even when the number of radio waves emitted from the transmitting station is smaller.

  In the positioning device according to the eighth embodiment of the present invention, the radio wave radiation time of each transmitting station does not need to be the same as that of other transmitting stations for the same reason as the positioning device of the seventh embodiment.

Embodiment 9 FIG.
In addition, the positioning unit 11 of the sixth embodiment may be adopted instead of the positioning unit 11 of the positioning device having the configuration of the seventh and eighth embodiments. In this way, the position of the mobile terminal can be estimated even in an environment where the number of equations with the clock error of the transmitting station and the position of the mobile terminal as unknowns are not sufficiently established.

  This is particularly the case when the number of transmitting stations covering the area where the mobile terminal to be measured is present is small (when N is a small value) or when the number J of mobile terminals is not sufficient relative to the number N of transmitting stations. However, if the radio wave arrival time of the mobile terminal at different times is used, and the process of temporarily calculating the clock error and the position of the mobile terminal is repeated, and if a certain standard is satisfied, transmission is performed, Even when there is a clock error between stations, the position of the mobile terminal can be measured.

  In addition, although the positioning method shown in Embodiments 1 to 9 has been described by taking the case of using radio waves as an example, the present invention is not limited to this, and this method can be applied even when used for sound waves or light waves. It is. Further, the case where the position of the mobile terminal is measured in three dimensions has been described, but even in the case of two dimensions, the altitude direction can be calculated by using conditions such as the presence of the mobile terminal on the surface of the ground. Furthermore, the functions of the positioning unit of the present invention described above can be executed by operating the CPU based on a software program.

  As an application example of the present invention, for example, in cellular communication using an unsynchronized base station, a clock error between base stations is calculated using radio waves from a mobile terminal, and synchronization between base stations is established. It is possible to do.

It is a block diagram which shows the function structure of the positioning apparatus by Embodiment 1 of this invention. It is a block diagram which shows the other function structure of the positioning part which concerns on Embodiment 1 of this invention. It is a block diagram which shows the function structure of the positioning apparatus by Embodiment 2 of this invention. It is a block diagram which shows the structural example of the temporary clock error calculation part which concerns on Embodiment 2 of this invention. It is a block diagram which shows the other structural example of the temporary clock error calculation part which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structural example of the positioning process control part which concerns on Embodiment 2 of this invention. It is a block diagram which shows the other structural example of the positioning process control part which concerns on Embodiment 2 of this invention. It is a block diagram which shows the function structure of the positioning apparatus by Embodiment 3 of this invention. It is a block diagram which shows the function structure of the positioning apparatus by Embodiment 4 of this invention. It is a block diagram which shows the structural example of the multiple provisional clock error calculation part which concerns on Embodiment 4 of this invention. It is a block diagram which shows the other structural example of the multiple temporary clock error calculation part which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structural example of the multiple positioning process control part which concerns on Embodiment 4 of this invention. It is a block diagram which shows the other structural example of the multiple positioning process control part which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structural example of the positioning apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structural example of the positioning apparatus which concerns on Embodiment 6 of this invention. It is a block diagram which shows the structural example of the positioning apparatus which concerns on Embodiment 7 of this invention.

Explanation of symbols

1 ₁ to 1 _N sensor, 2 arrival time difference calculation unit, 3 positioning unit, 31 collective positioning unit, 32 motion model setting unit, 33 motion model positioning unit, 34 provisional positioning unit, 35 mismatch time calculation unit, 36 provisional clock error calculation Unit, 37 positioning processing control unit, 361 average processing unit, 362 weighting processing unit, 371 processing number counting unit, 372 residual processing unit, 4 ₁ to 4 _N sensor, 5 multiple arrival time difference calculating unit, 6 multiple positioning unit, 61 Multiple batch positioning unit, 64 Multiple provisional positioning unit, 65 Multiple mismatch time calculation unit, 66 Multiple temporary clock error calculation unit, 67 Multiple positioning processing control unit, 661 Multiple average processing unit, 662 Multiple weighting processing unit, 671 Multiple processing count Unit, 672 multiple residual processing unit, 7 targets, 8 ₁ to 8 _N transmitting station, 9 receiving station, 10 mobile terminal, 10 ₁ to 10 _J mobile terminal, 11 positioning unit, 13 transmission Transport time difference calculation unit, 15 Base station control device.

Claims (16)

In a positioning device that receives radio waves radiated or reflected from a target by a plurality of sensors and calculates the position of the target based on the arrival time difference of the received radio waves,
An arrival time difference calculation unit for calculating an arrival time difference of radio waves received by each sensor multiple times;
Based on the calculated arrival time difference between each sensor, a clock error between the sensors and a positioning unit that calculates a target position at each time the radio wave is received,
The positioning unit is
Create an equation for each radio wave reception time that the distance obtained by multiplying the corrected arrival time difference of the radio wave between the input sensors by the speed of the radio wave is equal to the difference in the propagation distance of the radio wave. A temporary positioning unit that calculates a temporary position of a target at each time by solving for each reception time;
The goal of the provisional position and the difference between the time obtained by dividing the radio wave speed of the distance of each sensor, is subtracted from TDOA of a radio wave between the sensor, the mismatch time calculation unit for calculating a mismatch time at each time When,
A provisional clock error calculation unit for calculating a provisional clock error between the sensors based on the calculated mismatch time;
The provisional clock error calculated by the provisional clock error calculation unit is subtracted from the radio wave arrival time difference to obtain a corrected radio wave arrival time difference between the sensors and output to the provisional positioning unit. parts, to complete the series of positioning processing by the mismatch time calculation unit and the provisional clock error calculating unit, the provisional clock error and provisional position of the target obtained by the respective processes as the final target position and clock error A positioning process control unit that outputs or controls the series of positioning processes to be continued again. The provisional positioning portion, when there is no correction TDOA of radio waves between the sensor input, the positioning device according to claim 1, wherein the creating equations using the arrival time difference of the radio wave between the sensor . The provisional clock error calculating unit, the positioning of claim 1, wherein the average value of the mismatching time calculated by the mismatch time calculation unit, with an average processing unit for calculating a provisional clock error between the sensor apparatus. The provisional clock error calculating unit, further comprising a weighting processing unit for calculating a provisional clock error between sensors by weighting the mismatch time calculated by the mismatch time calculating unit using a weighting factor calculated by a predetermined method The positioning device according to claim 1 . The positioning processing control unit counts the number of times of execution of the series of positioning process determines that to complete the series of positioning processing when the count reaches a predetermined count value, whereas, the number of counts any of claims one of claims 4, characterized in that it comprises a process of determining the number of times counting unit and is implemented to continue the series of positioning process again if does not reach the predetermined count value 1 The positioning device described in the item. The positioning processing control unit, interim calculated in residuals and / or the previous treatment of the provisional position of the target obtained in the above and the provisional position of the target determined by the provisional positioning unit currently being processed by the previous treatment When the residual between the clock error and the provisional clock error obtained by the current process is smaller than a predetermined value, it is determined that the series of positioning processes is completed, and when the residual is larger than the predetermined value. positioning device according to any one of claims 1 to 4, characterized in that with a residual processing unit determines that is performed to continue the series of positioning process again. In a positioning device that receives radio waves radiated or reflected from a target by a plurality of sensors and calculates the position of the target based on the arrival time difference of the received radio waves,
A plurality of arrival time difference calculation units for calculating the arrival time difference of radio waves from a plurality of targets received by each sensor;
Based on the calculated time difference of arrival of radio waves between each sensor, a plurality of positioning units that calculate the clock error between each sensor and each target position,
The plurality of positioning units are
Create an equation for each target that the distance obtained by multiplying the corrected arrival time difference of the radio wave between the input sensors by the velocity of the radio wave is equal to the difference in the propagation distance of the radio wave. Multiple provisional positioning units that calculate the provisional position of each target by solving,
The difference time obtained by dividing the radio wave speed of the distance of each target temporary position and the sensor, is subtracted from TDOA of a radio wave between the sensor, a plurality mismatches time is calculated as the mismatch time in each target A calculation unit;
A plurality of provisional clock error calculation units for calculating a provisional clock error between the sensors based on the calculated mismatch time;
Subtract the provisional clock error calculated by the plurality of provisional clock error calculation unit from the arrival time difference of the radio wave to obtain a corrected arrival time difference of the radio wave between the sensors and output to the plurality of provisional positioning unit, multiple provisional positioning portion, said plurality mismatches to complete the series of positioning processing by the time calculation unit and the plurality provisional clock error calculating unit, each final interim clock error and tentative positions of each target obtained by this the process A positioning apparatus comprising: a plurality of positioning processing control units that output a target position and a clock error, or perform control so that the series of positioning processing is continued again. The positioning according to claim 7, wherein the plurality of provisional positioning units create an equation using the difference in arrival time of radio waves between sensors when there is no difference in correction arrival time of radio waves between the input sensors. apparatus. Wherein the plurality provisional clock error calculating unit according to claim wherein the average value of a plurality mismatched mismatched time calculated by the time calculation unit, provided with a plurality averaging processor that calculates a provisional clock error between sensors 7 The described positioning device. Wherein the plurality provisional clock error calculating unit, a plurality weighting processing unit for calculating a provisional clock error between sensors by weighting the plurality mismatch mismatch time calculated by the time calculating unit using a weighting factor calculated by a predetermined method The positioning device according to claim 7 , wherein the positioning device is provided. Wherein the plurality positioning processing control unit counts the number of times of execution of the series of positioning process determines that to complete the series of positioning processing when the count reaches a predetermined count value, whereas, the number of counts of claims 1 0 to claim 7, characterized in that it comprises a plurality number of times of processing count unit determines that is performed to continue the series of positioning process again but if does not reach the predetermined count value The positioning device according to any one of claims. Wherein the plurality positioning processing control unit, the previous treatment with the plurality provisional positioning unit in residual and / or the previous treatment of the provisional location of each target determined by the temporary position and the current process of each target determined When the residual between the temporary clock error obtained in step 1 and the temporary clock error obtained in the current process is smaller than a predetermined value, it is determined that the series of positioning processes is completed, while the residual is smaller than the predetermined value. claims 7, characterized in that it comprises a plurality residual processing unit determines that is performed to continue the series of positioning process again in the case is large according to any one of claims 1 0 Positioning device. A plurality of transmitting stations installed at a predetermined position, and transmitting a radio wave toward a mobile terminal when a predetermined radiation time is reached based on a clock unique to the own station; and
A reception station transmitted from the mobile terminal, an arrival time of radio waves from the transmission station observed in the mobile terminal and identification information of a transmission station that is a radiation source of the incoming radio waves identified in the mobile terminal;
Based on the radiation time of the plurality of transmitting stations, the radio wave arrival time acquired by the receiving station, the identification information of the transmitting station, and the positions of the plurality of transmitting stations, the clock error inherent to the plurality of transmitting stations and the movement A base station controller that calculates the position of the terminal, and a positioning device comprising:
The base station controller is
The propagation time difference that calculates the radio wave propagation time difference between each transmitting station using the arrival time of the radio wave at the mobile terminal, the identification information of the transmitting station that is the radiation source of this radio wave, and the radio wave radiation time by the clock unique to that transmitting station A calculation unit;
A positioning unit that calculates a position of the mobile terminal and a clock error between the plurality of transmitting stations based on the calculated propagation time difference of radio waves between the transmitting stations;
The positioning unit is
Create an equation for each mobile terminal that the distance obtained by multiplying the radio wave velocity by the radio wave correction propagation time difference between the input transmitting stations is equal to the radio wave propagation distance difference, and move these equations A temporary positioning unit that calculates a temporary position of each mobile terminal by solving for each terminal;
The time obtained by dividing the difference between the temporary position of each mobile terminal and each transmitting station by the speed of the radio wave is subtracted from the radio wave propagation time difference between each transmitting station to calculate the mismatch time at each mobile terminal. A mismatch time calculation unit,
A provisional clock error calculation unit for calculating a provisional clock error between the transmitting stations based on the calculated mismatch time;
The provisional clock error calculated by the provisional clock error calculation unit is subtracted from the propagation time difference of the radio wave to obtain a corrected propagation time difference of the radio wave between the transmitting stations and output to the temporary positioning unit. A series of positioning processes by the positioning unit, the mismatch time calculation unit, and the provisional clock error calculation unit are completed, and the provisional position and the provisional clock error of each mobile terminal obtained in each processing are determined for each final mobile terminal. A positioning processing control unit which outputs a position and a clock error, or controls to continuously execute the series of positioning processing again . Wherein the plurality of transmission stations, radiates radio waves to a plurality of said mobile terminal in a predetermined radiation time,
The receiving station receives the radio wave arrival time from the transmitting station observed at the plurality of mobile terminals and the identification information of the transmitting station that is the radiation source of the incoming radio wave identified at the plurality of mobile terminals. positioning device according to claim 1 3, wherein the benzalkonium transmitted from the mobile terminal. Wherein the plurality of transmission stations, radiates radio waves toward the mobile terminal in a plurality of predetermined radiation time,
The receiving station transmits, from the mobile terminal, radio wave arrival times from the transmitting station observed at the mobile terminal a plurality of times and identification information identifying the transmitting station that is the radiation source of each incoming radio wave. ,
The base station control device includes: a plurality of transmitting station emission times; a plurality of radio wave arrival times acquired by the receiving station; identification information of a transmitting station that is a source of each incoming radio wave; 14. The positioning apparatus according to claim 13 , wherein a clock error specific to the plurality of transmitting stations and a position of the mobile terminal are calculated based on the position. Wherein the plurality of transmission stations, toward the mobile terminal radiates radio waves in each of the first radiation time and the second radiation time,
The receiving station has a first radio wave arrival time and a second radio wave arrival time from the transmission station observed in the mobile terminal, and further a transmission station that is a radiation source of the incoming radio wave in the first radio wave arrival time. The identified identification information and the identification information that identifies the transmitting station that is the radiation source of the incoming radio wave at the second radio wave arrival time are transmitted from the mobile terminal,
The base station control device includes: a plurality of transmitting station emission times; a plurality of radio wave arrival times acquired by the receiving station; identification information of a transmitting station that is a source of each incoming radio wave; Based on the movement model that defines the position, the positional relationship of the mobile terminal at each of the first radio wave arrival time and the second radio wave arrival time, The positioning device according to claim 15, wherein the positioning device is calculated.

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