JP4129547B2 - Means for improving accuracy of earthquake displacement calculation - Google Patents

Description

  The present invention relates to a means for improving positioning calculation accuracy when measuring a vibration displacement such as a distortion or a displacement from a reference position of a structure to be measured.

  Measuring seismic displacement of structures such as buildings on bridges and shakers is very useful for research on improving earthquake resistance and preventing fatigue failure of structures. In order to measure this seismic displacement, it is necessary to precisely measure the positions of multiple measurement points distributed throughout the structure. For example, the measurement points used for analyzing the shaking of the wall of a building are generally distributed over a wide range. Exist. As a conventional positioning device, for example, as described in Patent Document 1, there is a device that measures the vibration displacement of a structure to be measured using radio waves.

  FIG. 8 is a configuration diagram of a conventional positioning device described in Patent Document 1. This positioning device includes a plurality of transmitters 1 provided for each measurement point and transmitting radio waves having different frequencies, a plurality of receiving antennas 3 arranged at different positions, and two of the plurality of receiving antennas 3. For at least three different combinations related to one receiving antenna 3, a phase difference for detecting a phase difference of the received radio waves between the two receiving antennas 3 related to each combination for each radio wave of a different frequency transmitted from the transmitter 1 For each radio wave having a different frequency transmitted from the detection means 14 and the transmitter 1, an intersection of at least three equiphase planes respectively derived from phase differences for at least three different combinations of the two receiving antennas 3 is obtained. A positioning calculation means 16 for estimating the position of the transmitter 1 that transmits radio waves of the frequency is provided. In FIG. 8, the positioning signal processing device 7 is configured by the phase difference detection means 14 and the positioning calculation means 16.

ここに、ｑ_i ＝［Ｘ_i ，Ｙ_i ，Ｚ_i ］は第ｉ受信アンテナの位置を、ｑ_j ＝［Ｘ_j ，Ｙ_j ，Ｚ_j ］は第ｊ受信アンテナの位置を、λは電波の波長を、ｋ_ijは整数値バイアスを、Ｍは受信アンテナの個数を示す。なお，整数値バイアスｋ_ijは位相差２πのアンビギュィティ（曖昧さ）を表しているが、観測された各位相差を積算した位相差積算値を追尾すること等により整数値バイアスｋ_ijは決定される。 In this positioning signal processing device, the received signals from the plurality of receiving antennas 3 are digitally converted by the A / D converter 6, and the phase difference detecting means 14 detects the phase difference Δφ _ij (i, i, r ₎ between the digital received signals r _i and r _j . jε [1,..., M], i ≠ j) is calculated. The positioning calculation means 16 estimates the position of the measurement point, that is, the position p = [x, y, z] of the moving transmitter 1 by solving the following simultaneous equations obtained from the plurality of phase differences Δφ _ij. .

Here, q _i = [X _i , Y _i , Z _i ] is the position of the i th receiving antenna, q _j = [X _j , Y _j , Z _j ] is the position of the j th receiving antenna, and λ is the radio wave. , K _ij is an integer bias, and M is the number of receiving antennas. The integer value bias k _ij represents the ambiguity of the phase difference 2π, but the integer value bias k _ij is determined by tracking the phase difference integrated value obtained by integrating the observed phase differences. .

JP 2001-272448 A (paragraph 0007)

The conventional positioning signal processing apparatus is configured as described above, and the relationship of the above formula (1) is based on an ideal state in which the received signal consists only of a direct wave from the transmitter 1. However, when such a positioning signal processing apparatus is used indoors, in a building town, or in a mountainous area, the reception antenna 3 receives a multipath wave (reflected wave) in addition to the direct wave from the transmitter 1. There is a case. An error occurs in the observation value of the phase difference due to the interference of the multipath wave. When the observation error of the phase difference is large, there is a problem that the estimation accuracy of the position of the measurement point is greatly deteriorated.
If the phase difference observation error is large, the tracking process of the phase difference integrated value is erroneous, and the above equation (1) is solved using the integer value bias k _ij deviating from the true value. There is a problem that a large bias error may occur at the position of.

  The present invention has been made to solve the above-described problems, and is a means for improving positioning calculation accuracy capable of reducing deterioration in estimation accuracy of the position of a measurement point even when interference such as multipath waves occurs. The purpose is to obtain.

The means for improving the accuracy of vibration displacement calculation according to the present invention comprises: received power calculation means for calculating a received power level of a received signal from each receiving antenna that receives a radio wave transmitted from a position of a measurement point; From the storage means for storing the received power level of the signal, for each received signal, the received power level at the current time calculated by the received power calculating means, and the received power level at the past time stored in the storage means A determination means for comparing the obtained threshold value to determine the magnitude of the received power level at the current time, a phase difference detection means for detecting the phase difference between the received signals from the two reception antennas, and the determination means Phase difference selecting means for selecting a phase difference related to a received signal having a received power level greater than a threshold value from the phase differences detected by the phase difference detecting means based on the determination result; Is obtained by a positioning calculation means for estimating the position of the measurement point by the selected phase difference.

  The present invention has an effect that it is possible to reduce deterioration in estimation accuracy of the position of a measurement point in a three-dimensional space even when interference such as multipath waves occurs.

An embodiment of the present invention will be described below.
Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a positioning device that realizes a means for improving positioning calculation accuracy according to Embodiment 1 of the present invention. As shown in FIG. 1, a transmitter 1 and a transmission antenna 2 that transmit radio waves are installed at positions of measurement points in a three-dimensional space that is a measurement target such as a wall surface of a structure. Further, M receiving antennas 3 that receive radio waves transmitted from the position of the measurement point are arranged at different positions, and frequency conversion is performed to at least three different combinations of two receiving antennas 3 among the plurality of receiving antennas 3. The down converters 5 are connected to each other, and the two down converters 5 are connected to a local transmitter 4 that outputs a local oscillation signal. Further, each of the down converter 5, the received signal r _m analog (m = 1, ···, M ) via the A / D converter 6 for converting from the received signal r _m of the digital measurement of three-dimensional space It is connected to a positioning signal processing device 7 for estimating the position of the point, and the positioning signal processing device 7 is connected to the display means 8.

Positioning signal processor of FIG. 1 7, A / D converter 6 received power calculating means 11 for calculating a received power level of each received signal r _m digital from, each received signal calculated by the reception power calculating means 11 storage means 12 for storing the received power level of r _m, for each received signal r _m, the received power level at the current time calculated by the reception power calculating means 11, receiving the past time stored in the storage means 12 A determination means 13 is provided for determining the magnitude of the received power level at the current time by comparing the threshold value obtained from the average value of the power level.

Furthermore, the positioning signal processor 7, the phase difference of the received signals r _m from two receiving antennas 3, i.e., the phase difference between the digital reception signal r _i and the digital received signal r _j from the A / D converter 6 The phase difference detected by the phase difference detection means 14 based on the determination result of the phase difference detection means 14 and the determination means 13 for detecting Δφ _ij (i, jε [1,..., M], i ≠ j). from the [Delta] [phi _ij, phase difference selection means 15 for receiving power level of the current time to select the phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m, the phase difference [Delta] [phi _ij selected by the phase difference selection means 15 Positioning calculation means 16 for estimating the position p of the measurement point in the three-dimensional space using the above equation (1) is provided. The digital received signals r ₁ and r ₂ input to the phase difference detection unit 14a are input to the other phase difference detection units 14, respectively. The same applies to the received signal r _m of other digital.

  When estimating the position p = [x, y, z] of the measurement point in the three-dimensional space by the above equation (1), since there are three unknown variables, three equations, that is, at least four However, here, it is assumed that the positioning device has redundancy and the number M> 4 of the receiving antennas 3.

  FIG. 2 is a diagram for explaining a received electric field vector of the receiving antenna 3 due to multipath wave interference. In FIG. 2, the horizontal axis represents the real part (Re) of the received electric field vector, and the vertical axis represents the imaginary part (Im). 2A shows a case where the multipath wave is at a small level compared to the direct wave from the transmission antenna 2, and FIG. 2B shows that the multipath wave is larger than the direct wave from the transmission antenna 2. This shows a case where the electric field vector of the multipath wave is close to the phase opposite to that of the direct wave electric field vector.

As shown in FIG. 2A, when the multipath wave is at a small level, the combined received electric field vector of the receiving antenna 3 is not significantly different from the electric field vector of the direct wave, so the phase difference detecting means 14 The observation error of the phase difference Δφ _ij calculated by is relatively small. On the other hand, as shown in FIG. 2B, when the multipath wave is at a large level and the electric field vector of the multipath wave is close in phase to the electric field vector of the direct wave, the reception antenna 3 is synthesized. The length of the received electric field vector is reduced. At this time, when the received power level is equal to or less than the noise power level, the phase value observed from the received signal r _m are not accurate values become most noise random phase obtained. As a result, the observation error of the phase difference Δφ _ij calculated by the phase difference detecting means 14 increases and the positioning accuracy is greatly deteriorated.

FIG. 3 is a diagram showing temporal changes in the reception power level calculated by the reception power calculation means 11. When the position of the measurement points in the three-dimensional space has come to a position where multipath is enhanced accordingly vibration displacement, the reception power level is decreased as described above, the received power level of the received signal r _m of a receiving antenna 3 It changes as shown in FIG. 3 with the passage of time of the vibration displacement of the measurement point in the three-dimensional space. Therefore the received power level that the use of a higher received signal r _m than the threshold without lowering is likely to need not subjected to a large observation error of the phase difference [Delta] [phi _ij.

Therefore, in the first embodiment, with the configuration shown in FIG. 1, when the received power level is smaller than the threshold value obtained from the average value of the received power levels at past times, the received signal r _{m of the} receiving antenna 3 is received. The positioning process is performed using only the remaining observation values of the phase difference Δφ _ij without using the observation values of the phase difference Δφ _ij calculated from the above.

Next, the operation will be described.
In FIG. 1, a radio wave of a predetermined frequency is transmitted from a transmitter 1 and a transmission antenna 2 installed at measurement points in a three-dimensional space, and received by M reception antennas 3 arranged at different positions. r _m is obtained.

The down converter 5 which is connected at least three different combinations to the two receiving antennas 3 of the plurality of receiving antennas 3, performs frequency conversion of a received signal r _m a local oscillation signal from the local oscillator 4, A / D converter 6 outputs a positioning signal processor 7 converts the received signal r _m analog to the received signal r _m digital. In FIG. 1, only one set of the receiving antennas 3-1 and 3-2, the local oscillator 4, the down converters 5-1 and 5-2, and the A / D converters 6-1 and 6-2 is illustrated. The reception signals r ₁ and r ₂ from the A / D converters 6-1 and 6-2 are output to the positioning signal processing device 7. The reception signals r _i and r _j from at least three different combinations are output. It outputs to the positioning signal processing device 7.

In the positioning signal processing device 7, the received power calculation means 11 calculates the received power level at each time of the digital received signal r _m from the A / D converter 6, calculated received power level is stored in the storage means 12 Is done. The judging unit 13 compares the received power level at the current time calculated by the received power calculating unit 11 with a threshold value obtained from the average value of the received power levels at the past time stored in the storage unit 12. Te, determines the magnitude of the received power level at the present time, for example, received power level and notifies the number of the respective threshold smaller received signal r _m to the phase difference selecting means 15 and positioning means 16.

Phase difference detecting means 14 is the phase difference [Delta] [phi _ij (i digital received signal r _i and the digital received signal r _j from the A / D converter 6, j∈ [1, ···, M], i ≠ j ) And output to the phase difference selecting means 15. The phase difference selecting unit 15 receives the received signal r having a received power level at the current time smaller than each threshold value based on the determination result of the determining unit 13 from the phase difference Δφ _ij detected by the phase difference detecting unit 14. remove the phase difference [Delta] [phi _ij relates _m, the received power level of the current time by selecting the phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m and outputs for the positioning calculation unit 16.

The positioning calculation means 16 solves the above equation (1) of the simultaneous equations relating only to the observation value of the phase difference Δφ _ij selected by the phase difference selection means 15 based on the determination result of the determination means 13 to calculate the measurement points in the three-dimensional space. Estimate the position p = [x, y, z]. In the above equation (1), (Δφ _ij + 2πk _ij ) is a phase difference integrated value obtained by integrating the phase difference Δφ _ij at each time by the positioning calculation means 16, and the integer value bias k _ij is calculated from a known initial value. It is an integer value that can be determined by tracking the phase difference integrated value. The estimated position p = [x, y, z] of the measurement point in the three-dimensional space is output to the display means 8 and displayed.

As an example, the receiving by the number M = 6 antennas 3, as an observed value of the phase difference [Delta] [phi _ij, the received signal _{r 1, r 2, r 3} , r 4, r 5, the phase difference [Delta] [phi ₁₂ observed by r _6, A case where Δφ ₂₃ , Δφ ₃₄ , Δφ ₄₅ , and Δφ ₅₆ are obtained will be described. In this case, the determination by the determination unit 13 result, the received power level of the received signal r ₄ of the receiving antenna 3-4 is smaller than the threshold value. In this case, the determination means 13 notifies the phase difference selection means 15 and the positioning calculation means 16 of the received signal r ₄ that is smaller than the threshold value. The phase difference selection means 15 selects and outputs the phase differences Δφ ₁₂ , Δφ ₂₃ , Δφ ₅₆ observed by the received signals r ₁ , r ₂ , r ₃ , r ₅ , r ₆ to the positioning calculation means 16 for positioning calculation. The means 16 estimates the position p = [x, y, z] of the measurement point in the three-dimensional space by the three simultaneous equations according to the following equations (2), (3), and (4).

Furthermore, when the reception power level of the received signal r ₂ is smaller than the threshold value as a result of determination by the determination unit 13 at another time, the positioning calculation unit 16 determines the position selected by the phase difference selection unit 15. The position p = [x, y, z] of the measurement point in the three-dimensional space is estimated from the phase differences Δφ ₃₄ , Δφ ₄₅ , Δφ ₅₆ .

As described above, according to the first embodiment, calculates the received power level of the received power calculating means 11 receives signals r _m, the received power determination unit 13 is the current time calculated by the reception power calculating means 11 The level is compared with the threshold value obtained from the average value of the received power level at the past time stored in the storage means 12, the magnitude of the received power level at the current time is determined, and the phase difference detecting means 14 detects the phase difference [Delta] [phi _ij of the received signal r _m from two different receiving antennas 3, a phase difference selecting means 15, from among the detected phase difference [Delta] [phi _ij by the phase difference detecting means 14, determination means 13 the determination result the current time of the received power level based on the selected phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m, positioning calculation means 16 3 by the phase difference [Delta] [phi _ij selected by the phase difference selection means 15 Dimensional space total By estimating the position p of the measurement point, even when interference such as a multipath wave occurs, it is possible to reduce the deterioration of the estimation accuracy of the position p of the measurement point in the three-dimensional space.

  In the first embodiment, the threshold value used when the determination unit 13 determines the reception power level is obtained from the average value of the past reception power levels. The threshold value may be obtained from the excluded average value, and more stable determination can be performed. In addition, the threshold value may be obtained from a moving average over a fixed time, and when the direct wave reception power level can be estimated in advance, the threshold value may be determined based on the value.

Further, in the first embodiment, but the setting of the threshold set for each receiving antenna 3, when the reception level of the direct wave of each received signal r _m is uniform, common across the receiving antenna 3 A threshold may be set. Also, if the direct wave of the received level of the received signal r _m of each receiving antenna 3 is uniform, instead of the time average, the threshold an average value of the received power level of the received signal r _m each receive antenna 3 The same effect can be obtained.

Furthermore, in this first embodiment, although select the phase difference [Delta] [phi _ij the phase difference selecting means 15 observes, the received signal r _m received power level is small, which is input to the phase difference detecting means 14, the received power level may be configured as to switch to a larger received signal r _m.

Furthermore, in this first embodiment, although configured to perform calculation of the position p of the measurement points selected and the three-dimensional space the observed phase difference [Delta] [phi _ij, received power level of each received signal r _m The weighted least squares solution of the simultaneous equations of the above equation (1) can also be output as the position p of the measurement point in the three-dimensional space.

Although in the above-mentioned first embodiment, although estimates the position p of the measurement points in the three-dimensional space from the phase difference [Delta] [phi _ij between the received signal r _m, it is also possible to determine the arrival time difference between the received signal r _m is there.

Embodiment 2. FIG.
FIG. 4 is a block diagram of a positioning signal processing apparatus for realizing a means for improving positioning calculation accuracy according to Embodiment 2 of the present invention. This positioning signal processing device 7 is obtained by adding smoothing means 17 to the positioning signal processing device 7 shown in FIG. 1 of the first embodiment. The smoothing unit 17 receives the phase difference [Delta] [phi _ij from the phase difference detecting means 14, based on an instruction determination unit 13, the received power level as much phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m and it outputs the phase difference selection unit 15, the phase difference [Delta] [phi _ij relates preset predetermined time threshold smaller than the received signal is the received power level at the (observation cycle × number of samples) in the r _m, phase difference selection means without outputting to 15, the received power level is estimated smoothing the phase difference integrated value obtained by integrating the phase difference [Delta] [phi _ij obtained by the tracking processing (memory track) of past received signals r _m greater than the threshold value The phase difference Δφ _ij is output to the phase difference selecting means 15.

In FIG. 4, the determination unit 13 calculates the received power level at the current time calculated by the received power calculation unit 11 and the average value of the received power levels at the past time stored in the storage unit 12. by comparing the threshold, to determine the magnitude of the received power level at the present time, the reception power level of a received signal r _m is at times within a preset predetermined time (observation cycle × number of samples), when it becomes smaller than the threshold value, the smoothing means 17 relates the received signal r _m, without outputting the phase difference [Delta] [phi _ij from the phase difference detector 14, the phase difference [Delta] [phi _ij estimated smoothed with issues an instruction to output, reception power level output from the smoothing means 17 to the phase difference selection unit 15 is estimated phase difference [Delta] [phi _ij and smoothing relates threshold greater than the received signal r _m a phase difference [Delta] [phi _ij Finger to select The issue.

The determination means 13, the result of the determination, the received power level of a received signal r _m is a preset predetermined time (observation cycle × number of samples) or longer, when less than the threshold value continues , determination means 12, but issues an instruction to output the phase difference [Delta] [phi _ij estimated smoothing the smoothing means 17 relates the received signal r _m, the phase difference selection unit 15, output from the smoothing means 17 have been without selecting the smoothed estimated phase difference [Delta] [phi _ij, received power level instructs to select only the phase difference [Delta] [phi _ij obtained from the threshold is greater than the received signal r _m.
The other received power calculation means 11, storage means 12, phase difference detection means 14, and positioning calculation means 16 are the same as the positioning signal processing device 7 shown in FIG.

Next, the operation will be described.
In order to correctly estimate the position of the measurement point, it is necessary to accurately estimate not only the phase difference Δφ _ij but also the integer value bias k _ij in the phase difference integrated value (Δφ _ij + 2πk _ij ) in the above equation (1). is there.

FIG. 5 is a diagram showing an example of the temporal change of the phase difference integrated value when the temporal change in the received power level of the received signal and the displacement of the position of the measurement point take a reciprocating motion due to an earthquake or the like. In FIG. 5, white circles indicate phase difference integrated values (Δφ _ij) accumulated by the positioning calculation means 16 using the observed phase difference Δφ _ij from the phase difference detection means 14 when the received power level is greater than the threshold value. + 2πk _ij ), and the black triangle points are the positions accumulated by the positioning calculation means 16 using the phase difference Δφ _ij with a large observed error from the phase difference detection means 14 when the received power level is smaller than the threshold value. The phase difference integrated value (Δφ _ij + 2πk _ij ), the white triangular point is the phase difference integrated value (Δφ _ij + 2πk _ij ) with the subsequent integer value bias error, and the black circle point is the threshold value of the received power level a phase difference integrated value positioning calculation unit 16 is integrated with the smoothed estimated phase difference [Delta] [phi _ij based on historical phase difference [Delta] [phi _ij by smoothing means 17 is smaller than (Δφ _ij + 2πk _ij).

When the displacement of the position of the measurement point takes a reciprocating motion due to an earthquake or the like, the position of the measurement point starts to move in one direction from the initial position, and at that time, the phase difference between the transmitter 1 and the two receiving antennas 3 When the distance difference between the transmitter 1 and one receiving antenna 3 is increased, the phase difference integrated value (Δφ _ij + 2πk) obtained by the positioning calculation means 16 as shown by the white circles in FIG. _ij ) changes in an increasing direction. When the position of the measurement point is displaced in the opposite direction from there, the displacement is shifted in a direction in which the distance difference between the transmitter 1 and the reception antenna 3 is reduced until the position returns to the initial position, and the phase difference integrated value ( Δφ _ij + 2πk _ij ) changes in a decreasing direction.

When the received power level is larger than the threshold value, the phase difference integrated value (Δφ _ij + 2πk _ij ) obtained by integrating the phase difference Δφ _ij output from the phase detecting unit 14 by the positioning calculation unit 16 is the white circle in FIG. However, when the received power level becomes lower than the threshold value due to multipath or the like, the noise power level becomes equal to or less than the threshold value, and the phase difference Δφ _ij output from the phase difference detecting means 14 is If a large error occurs instantaneously and the positioning calculation means 16 simply continues to accumulate the phase difference Δφ _{ij in} which the error has occurred, the phase difference integrated value (Δφ _ij + 2πk _ij ) is the black triangle or white triangle in FIG. As shown by the point, a large error occurs even in the time after the reception power level is recovered, and the integer value bias k _ij may be greatly mistaken.

Such reception phase difference accumulation value related to the received signal r _m power level drops temporarily (Δφ _ij + 2πk _ij) there is no problem in subsequently have to use temporarily, any other received signal r _m also multi If the received power level decreases due to the path, the number of received signals is insufficient at the end, and the position of the measurement point cannot be determined.

Accordingly, in the second embodiment, when the received power level becomes smaller, instead of the phase difference [Delta] [phi _ij output from the phase difference detecting means 14, the smoothed estimated position based on the past of the phase difference [Delta] [phi _ij correctly determine the integer ambiguity k _ij by interpolating the phase difference integrated value (Δφ _ij + 2πk _ij) using the phase difference [Delta] [phi _ij.

In FIG. 4, the determination unit 13 is a threshold value obtained from the average value of the received power level at the current time calculated by the received power calculation unit 11 and the received power level at the past time stored in the storage unit 12. compared bets, to determine the magnitude of the received power level at the present time, the reception power level of a received signal r _m is at times within a preset predetermined time (observation cycle × number of samples), the threshold when is smaller than the value, it outputs the smoothing means 17 relates the received signal r _m, without outputting the phase difference [Delta] [phi _ij from the phase difference detector 14, the phase difference [Delta] [phi _ij estimated smoothed to so with instructs the received power level output from the smoothing means 17 to the phase difference selection unit 15 is estimated phase difference [Delta] [phi _ij and smoothing relates threshold greater than the received signal r _m phase difference [Delta] [phi _ij I will select It issues an instruction.

Smoothing means 17 is output to the phase difference selection unit 15 inputs the phase difference [Delta] [phi _ij from the phase difference detecting means 14, indicated received power level is about threshold smaller than the received signal r _m by determining means 13 appropriate smoothing means 17, without outputting the phase difference [Delta] [phi _ij from the phase difference detecting means 14, the phase difference received power level by integrating the phase difference [Delta] [phi _ij by previously received signal r _m greater than the threshold value The smoothed and estimated phase difference Δφ _ij obtained by tracking the integrated value (memory track) is output to the phase difference selecting means 15. Phase selection means 15 based on an instruction of the judgment unit 13, the phase difference received power level output from the smoothing unit 17 is about greater than the threshold received signal r _m [Delta] [phi _ij and smoothing the estimated phase difference [Delta] [phi _ij Is output to the positioning calculation means 16.

The positioning calculation means 16 obtains the phase difference integrated value (Δφ _ij + 2πk _ij ) using the phase difference Δφ _ij output from the phase difference selection means 15. Here, for the received power level is less than the threshold received signal r _m, the phase difference integrated value by compensating with the phase difference [Delta] [phi _ij estimated smoothed by the smoothing means 17 (Δφ _ij + 2πk _ij ) seeking. That is, as shown in FIG. 5, when the received power level is smaller than the threshold value, the phase difference integrated value (Δφ _ij) indicated by the black circle points integrated using the phase difference Δφ _ij smoothed and estimated by the smoothing means 17. + 2πk _ij ). Then, the positioning calculation means 16 correctly determines the integer value bias k _ij from the phase difference integrated value (Δφ _ij + 2πk _ij ) obtained using the smoothed and estimated phase difference Δφ _ij and uses the above equation (1). Then, the position p = [x, y, z] of the measurement point in the three-dimensional space is estimated.

Further, the determination means 13 is a threshold value obtained from the average value of the received power level at the current time calculated by the received power calculation means 11 and the received power level at the past time stored in the storage means 12. compared bets, to determine the magnitude of the received power level at the present time, there received power level of the received signal r _m is a preset predetermined time (observation cycle × number of samples) over time, continued is smaller than the threshold value Te, the determination means 13, the smoothing means 17 relates the received signal r _m, but issues an instruction to output the estimated phase difference [Delta] [phi _ij smoothed, phase difference selection unit 15 selected for, without selecting a phase difference [Delta] [phi _ij estimated output smoothed from the smoothing means 17, the received power level is only the phase difference [Delta] [phi _ij obtained from the threshold is greater than the received signal r _m Give instructions to do.

Here, instructs to determining means 13 receives power level for the phase difference selecting means 15 selects only the phase difference [Delta] [phi _ij obtained from the threshold is greater than the received signal r _m is the received power level This is because the memory track by the smoothing means 17 becomes invalid and a large error occurs in the phase difference Δφ _ij estimated for smoothing when the time when the time becomes smaller than the observation period.

Phase selection means 15 based on an instruction of the judgment unit 13, positioning the received power level output from the smoothing means 17 selects only the phase difference [Delta] [phi _ij obtained from the threshold is greater than the received signal r _m Output to means 16. The positioning calculation means 16 obtains the phase difference integrated value (Δφ _ij + 2πk _ij ) using the phase difference Δφ _ij output from the phase difference selection means 15 to determine the integer value bias k _ij , and uses the above equation (1). Then, the position p = [x, y, z] of the measurement point in the three-dimensional space is estimated.
Other operations are the same as those in the first embodiment.

As described above, according to the second embodiment, even when the received power level becomes smaller than the threshold value due to multipath or the like and the observed phase difference Δφ _ij causes a large error instantaneously, the smoothing means 17 By interpolating the phase difference integrated value (Δφ _ij + 2πk _ij ) using the phase difference Δφ _ij smoothed and estimated based on the past phase difference Δφ _ij , the integer value bias k _ij is correctly determined to accurately measure the point with the position can be estimated once, the received signal r _m which the received power level becomes smaller, then a preset predetermined time received (observation cycle × number of samples) in the power level is larger than the threshold value when recovered, by seeking to interpolation phase difference accumulation value until it (Δφ _ij + 2πk _ij), it is possible to receive power level is correctly integrates the phase difference [Delta] [phi _ij after recovery, Ma The last is the received power level is temporarily successively smaller of the received signal r _m by-path effect of but avoiding that the number of the received signal is insufficient to obtain.

  In the second embodiment, the determining unit 13 manages a predetermined time (observation period × number of samples) set in advance, and the smoothing unit 17 and the phase difference are determined depending on whether the time is within the predetermined time or more than the predetermined time. Although the selection unit 15 is controlled, the determination unit 13 determines the position of the measurement point before the reception power level estimated by the positioning calculation unit 16 decreases and the position of the measurement point after the reception power level decreases. And the smoothing means 17 and the phase difference selecting means 15 may be controlled depending on whether the calculated position change amount is less than or equal to a predetermined threshold value or greater than a predetermined threshold value.

Embodiment 3 FIG.
FIG. 6 is a configuration diagram of a positioning signal processing apparatus according to Embodiment 3 of the present invention. This positioning signal processing device 7 is obtained by adding a smoothing means 17 and a phase difference estimating means 18 to the positioning signal processing device 7 shown in FIG. 1 of the first embodiment, and other configurations are the same as those of the first embodiment. This is the same as the positioning signal processing device 7 shown in FIG.

Here, phase difference estimation unit 18, the position p = [x of measurement points positioning calculation means 16 receives the power level is estimated using the phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m, y, z ] enter the received power level to estimate the phase difference [Delta] [phi _ij for each received signal r _m smaller than the threshold. Further, the smoothing unit 17 receives the phase difference [Delta] [phi _ij from the phase difference detecting means 14, based on an instruction determination unit 13, the received power level as it is the phase difference [Delta] [phi _ij relates threshold greater than the received signal r _m output to the phase difference selection unit 15, the received power level for the phase difference [Delta] [phi _ij for thresholds smaller received signal r _m, without outputting the phase difference selection unit 15, estimated by the phase difference estimating means 18 The phase difference Δφ _ij is output to the phase difference selecting means 15 as the smoothed and estimated phase difference Δφ _ij .

Next, the operation will be described.
FIG. 7 is a diagram showing an example of the temporal change of the phase difference integrated value when the temporal change of the received power level of the received signal and the displacement of the position of the measurement point take a reciprocating motion due to an earthquake or the like. 2 of the received power level of the received signal r _m than 5 indicates a case where the time becomes smaller than the threshold value is longer than the observation period.

In the second embodiment, the received signal r _m of the received power level is determined to be smaller than the threshold value, the smoothing unit 17, tracks the past retardation integrated value received power level is greater than the threshold value The smoothed and estimated phase difference Δφ _ij obtained by processing (memory track) was output. However, as shown in FIG. 7, when the time when the received power level is reduced is longer than the observation period, The memory track by the smoothing means 17 becomes invalid, and an error may occur in the integer value bias obtained by the positioning calculation means 16, and the position of the measurement point may not be accurately estimated.

Therefore, in the third embodiment, when the received power level is less than the threshold, smoothing means 17, the received power level is estimated using the phase difference [Delta] [phi _ij by greater than a threshold received signal r _m By outputting the phase difference Δφ _ij obtained by the phase difference estimation means 18 from the measured position p = [x, y, z], the positioning calculation means 16 correctly determines the integer value bias k _ij and accurately measures it. The position of a point is estimated.

In FIG. 7, white circles indicate phase difference integrated values (Δφ _ij) accumulated by the positioning calculation means 16 using the observed phase difference Δφ _ij from the phase difference detection means 14 when the received power level is greater than the threshold value. + 2πk _ij ), and the black triangle points are the positions accumulated by the positioning calculation means 16 using the phase difference Δφ _ij with a large observed error from the phase difference detection means 14 when the received power level is smaller than the threshold value. The phase difference integrated value (Δφ _ij + 2πk _ij ), the white triangular point is the phase difference integrated value (Δφ _ij + 2πk _ij ) with the subsequent integer value bias error, and the black circle point is the threshold value of the received power level The phase difference integrated value (Δφ _ij + 2πk _ij ) integrated by the positioning calculation means 16 using the phase difference Δφ _ij estimated by the phase difference estimating means 18 from the smoothing means 17 when it is smaller.

In the positioning signal processing means 7, the determination unit 13 determines the magnitude of the received power level at the present time, when the received power level of a received signal r _m is smaller than the threshold value, relative to smoothing means 17 with instructs not to output the phase difference selection unit 15 as the phase difference [Delta] [phi _ij from the phase difference detecting means 14, the received power level to the phase difference selection means 15 is obtained from the threshold is greater than the received signal r _m An instruction is issued to select only the phase difference Δφ _ij .

Phase selection means 15 based on an instruction of the judgment unit 13, the phase difference [Delta] [phi _ij from the phase difference detecting means 14 for outputting received power level is obtained from the threshold is greater than the received signal r _m from the smoothing means 17 Is output to the positioning calculation means 16. Positioning means 16, based on the instruction of the judgment unit 13 obtains the phase difference integrated value (Δφ _ij + 2πk _ij) using the phase difference [Delta] [phi _ij obtained from the received power level is greater than the threshold received signal r _m Then, the integer value bias k _ij is determined, the position p of the measurement point is estimated, and the determination means 13 is notified that the position p of the measurement point has been estimated.

The phase difference estimation means 18 calculates the distance from the estimated measurement point position p to the transmission antenna 2 and each reception antenna 3 at the measurement point, and the received signal r _m having a received power level smaller than the threshold value from the distance. phase difference integrated value relates to estimate the phase difference [Delta] [phi _ij seeking (Δφ _ij + 2πk _ij), he outputs the phase difference [Delta] [phi _ij estimated to smoothing means 17 for the received signal r _m of the received power level becomes smaller than the threshold value To do. The corresponding smoothing means 17 stores the phase difference Δφ _ij output from the phase difference estimating means 18 and prepares for the timing of the next observation period.

If the state where the received power level is smaller than the threshold value continues at the timing of the next observation period, the determination unit 13 makes the phase difference Δφ _ij from the phase difference detection unit 14 to the corresponding smoothing unit 17. Rather than instructing to output the phase difference Δφ _ij estimated by the phase difference estimating means 18, the received power level output from the smoothing means 17 is more than the threshold value to the phase difference selecting means 15. instructs to select the phase difference [Delta] [phi _ij and smoothing the estimated phase difference [Delta] [phi _ij relates larger received signal r _m.

Smoothing means 17, the received power level is output a phase difference [Delta] [phi _ij by greater than a threshold received signal r _m as the phase difference selection unit 15, the phase difference received power level is about threshold smaller than the received signal r _m Δφ _ij is not output to the phase difference selecting unit 15, but the phase difference Δφ _ij estimated by the phase difference estimating unit 18 is output to the phase difference selecting unit 15 as a smoothed estimated phase difference Δφ _ij .

Phase selection means 15, based on an instruction from the determination unit 13, a phase difference related to the output received power level is greater than the threshold received signal r _m from the smoothing means 17 [Delta] [phi _ij and smoothing the estimated phase difference [Delta] [phi _ij is selected and output to the positioning calculation means 16. The positioning calculation means 16 also uses the estimated phase difference to determine the integer value bias based on the instruction from the determination means 13, but the received power level is larger than the threshold value in the positioning process in order to increase the positioning accuracy. only by estimating the position p of the measurement point phase difference [Delta] [phi _ij obtained from the received signal r _m.

Phase difference estimation unit 18, the position p = the received power level is estimated by the positioning calculating means 16 using the phase difference [Delta] [phi _ij by greater than a threshold received signal r _m measurement points [x, y, z] from Then, the distance between the transmitting antenna 2 and each receiving antenna 3 at the measurement point is calculated, the phase difference integrated value (Δφ _ij + 2πk _ij ) is estimated from the distance, and the tracking of the phase difference Δφ _ij is continued.

Thereafter, when the received power level becomes higher than the threshold and recovers, the determination means 13 outputs the phase difference Δφ _ij from the phase difference detection means 14 to the phase difference selection means 15 to the smoothing means 17. And instruct the phase difference selecting means 15 to select the phase differences Δφ _ij from all the smoothing means 17.
Other operations are the same as those in the first embodiment.

Next, for example, when the number of receiving antennas 3 is M = 6, Δφ ₁₂ , Δφ ₂₃ , Δφ ₃₄ , Δφ ₄₅ , Δφ ₅₆ are obtained as observed phase differences output from the phase difference detecting means 14. The operation when the received signal r _{4 of} the fourth receiving antenna 3-4 is smaller than the threshold value will be described.
In this case, the determination unit 13 instructs the smoothing unit 17 not to output the phase differences Δφ ₃₄ and Δφ ₄₅ related to the _fourth received signal r ₄ which is smaller than the threshold value, and other threshold values. Instructs to output phase differences Δφ ₁₂ , Δφ ₂₃ , Δφ ₅₆ relating to larger received signals, and instructs phase difference selecting means 15 to detect phase differences Δφ ₁₂ , Δφ ₂₃ , relating to received signals larger than the threshold value. Instruct to select Δφ ₅₆ . The phase difference selection means 15 outputs the observed phase differences Δφ ₁₂ , Δφ ₂₃ , Δφ ₅₆ to the positioning calculation means 16, and the positioning calculation means 16 is an expression determined by Δφ ₁₂ , Δφ ₂₃ , Δφ ₅₆ as described above. The position p = [x, y, z] of the measurement point is estimated by the simultaneous equations (2) to (4).

上記式（５）、式（６）において、右辺の｛ ｝内の値が、観測された他の受信信号の位相差Δφ₁₂，Δφ₂₃，Δφ₅₆より推定した計測点の位置ｐ＝［ｘ，ｙ，ｚ］に基づき推定した送信アンテナ２と各受信アンテナ３までの距離を示している。位相差推定手段１８は、推定した位相差積算値（Δφ₃₄＋２πｋ₃₄），（Δφ₄₅＋２πｋ₄₅）より、位相差Δφ₃₄，Δφ₄₅を求めて該当する平滑手段１７に出力する。 The phase difference estimating means 18 inputs the estimated position p = [x, y, z], and calculates the phase difference integrated value (Δφ ₃₄ + 2πk ₃₄ ) and (Δφ ₄₅ + 2πk ₄₅ ) from the above equation (1). It is estimated from the following transformed equations (5) and (6).

In the above equations (5) and (6), the value in {} on the right side is the position of the measurement point p = [x estimated from the phase differences Δφ ₁₂ , Δφ ₂₃ , Δφ _{56 of} other observed received signals. , Y, z], the distance between the transmitting antenna 2 and each receiving antenna 3 estimated. The phase difference estimating means 18 obtains the phase differences Δφ ₃₄ and Δφ ₄₅ from the estimated phase difference integrated values (Δφ ₃₄ + 2πk ₃₄ ) and (Δφ ₄₅ + 2πk ₄₅ ) and outputs them to the corresponding smoothing means 17.

Output appropriate smoothing means 17 and the phase difference [Delta] [phi ₃₄ estimated by the phase difference estimating means 18, [Delta] [phi ₄₅ and outputs respectively, the phase difference [Delta] [phi _34, [Delta] [phi ₄₅ is selected by the phase difference selection unit 15 to the positioning computation unit 16 Then, the positioning calculation means 16 obtains the phase difference integrated values (Δφ ₃₄ + 2πk ₃₄ ) and (Δφ ₄₅ + 2πk ₄₅ ) using the phase differences Δφ ₃₄ and Δφ ₄₅ as shown by the black circles in FIG. The integer value bias is correctly determined, and the position p = [x, y, z] of the measurement point is estimated.

As described above, according to the third embodiment, even when the received power level becomes smaller than the threshold due to multipath or the like and the observed phase difference Δφ _ij causes a large error in a relatively long time, retardation estimating means 18, the measurement points are estimated by using the phase difference [Delta] [phi _ij received power level by greater than a threshold received signal r _m position p = [x, y, z ] estimates the phase difference [Delta] [phi _ij from and, positioning means 16, by interpolating the phase difference integrated value (Δφ _ij + 2πk _ij) using the estimated phase difference [Delta] [phi _ij, the position of accurately measured points to determine the correct integer ambiguity k _ij it is possible to estimate the once the received signal r _m which the received power level becomes smaller, then, when the received power level is restored is larger than the threshold value, the phase difference accumulation value so far (Δφ _ij + 2πk _ij) to interpolate By seeking can receive power level is correctly integrates the phase difference [Delta] [phi _ij after recovery, finally received signal received power level becomes temporarily successively smaller of the received signal r _m Multipath The effect of avoiding the shortage of numbers is obtained.

Incidentally, in the third embodiment, by using the position of the measurement points which are estimated from the observed phase difference [Delta] [phi _ij by another reception signal _{r m p = [x, y} , z], strong by multipath or the like interference While receiving and phase difference [Delta] [phi _ij estimate of the received signal r _m and the, when the moving speed of the measurement point is sufficiently slower than the observation period, the phase difference [Delta] [phi _ij observed by other received signal r _m instead of the estimated position of the measuring point, by using the position of the estimated measurement points immediately before, it is also possible to estimate the phase difference [Delta] [phi _ij of the received signal r _m which receives strong interference.

  Although the first to third embodiments have been described with the configuration performed by digital processing, a part or all of the configuration may be performed by analog processing.

It is a block diagram of the positioning apparatus which implement | achieves the positioning calculation precision improvement means by Embodiment 1 of this invention. It is a figure explaining the received electric field vector of the receiving antenna by interference of a multipath wave. It is a figure which shows the time change of the reception power level which the reception power calculation means of the positioning signal processing apparatus which implement | achieves the positioning calculation precision improvement means by Embodiment 1 of this invention calculates. It is a block diagram of the positioning signal processing apparatus which implement | achieves the positioning calculation accuracy improvement means by Embodiment 2 of this invention. In the positioning signal processing apparatus that realizes the means for improving the positioning calculation accuracy according to the second embodiment of the present invention, the temporal change in the received power level of the received signal and the displacement of the position of the measuring point take a reciprocating motion due to an earthquake or the like. It is a figure which shows the example of the time change of a phase difference integrated value. It is a block diagram of the positioning signal processing apparatus which implement | achieves the improvement means of the positioning calculation precision by Embodiment 3 of this invention. In the positioning signal processing apparatus that realizes the means for improving the positioning calculation accuracy according to Embodiment 3 of the present invention, the temporal change in the received power level of the received signal and the displacement of the position of the measuring point take a reciprocating motion due to an earthquake or the like. It is a figure which shows the example of the time change of a phase difference integrated value. It is a block diagram of the conventional positioning apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Transmitter, 2 Transmitting antenna, 3 Receiving antenna, 4 Local transmitter, 5 Down converter, 6 A / D converter, 7 Positioning signal processing apparatus, 8 Display means, 11 Received power calculation means, 12 Storage means, 13 Determination Means, 14 phase difference detection means, 15 phase difference selection means, 16 positioning calculation means, 17 smoothing means, 18 phase difference estimation means.

Claims (4)

Received power calculation means for calculating the received power level of the received signal from each receiving antenna that receives the radio wave transmitted from the position of the measurement point;
Storage means for storing the received power level of each received signal calculated;
For each received signal, the received power level at the current time calculated by the received power calculating means is compared with the threshold value obtained from the received power level at the past time stored in the storage means, and the current time Determining means for determining the magnitude of the received power level;
Phase difference detection means for detecting a phase difference between received signals from two receiving antennas;
Based on the determination result of the determination unit, a phase difference selection unit that selects a phase difference related to a received signal having a reception power level greater than a threshold value from the phase differences detected by the phase difference detection unit;
Means for improving the accuracy of vibration displacement calculation comprising positioning calculation means for estimating the position of the measurement point based on the selected phase difference. Based on the instruction from the determination means, the phase difference relating to the received signal whose received power level detected by the phase difference detection means is larger than the threshold value is output to the phase difference selection means as it is, and is detected in advance by the phase difference detection means. A smoothing estimation obtained by tracking the phase difference integrated value obtained by integrating the phase difference of the past received signal with respect to the phase difference related to the received signal whose received power level is smaller than the threshold value within the set predetermined time. Smoothing means for outputting the phase difference to the phase difference selecting means,
The phase difference selecting means selects, based on an instruction from the determining means, a phase difference and a smoothing estimated phase difference related to a received signal whose received power level output from the smoothing means is greater than a threshold value. The means for improving the vibration displacement calculation accuracy according to claim 1. The phase difference selection unit is configured to apply a phase difference from the smoothing unit to a phase difference related to a received signal having a reception power level smaller than a threshold value for a predetermined time or more detected by the phase difference detection unit based on an instruction from the determination unit. 3. The means for improving the accuracy of calculation of vibration displacement position according to claim 2, wherein the output smoothed estimated phase difference is not selected. Phase difference estimating means for estimating a phase difference relating to a received signal having a received power level smaller than the threshold from a position of a measurement point estimated by the positioning calculation means using a phase difference relating to the received signal having a received power level larger than the threshold value When,
Based on the instruction from the judging means, the phase difference relating to the received signal whose received power level detected by the phase difference detecting means is larger than the threshold value is output to the phase difference selecting means as it is, and the reception detected by the phase difference detecting means is also received. A smoothing unit that outputs the phase difference estimated by the phase difference estimation unit to the phase difference selection unit as a smoothed estimated phase difference for a phase difference related to a received signal having a power level smaller than a threshold value,
The phase difference selecting means selects, based on an instruction from the determining means, a phase difference and a smoothing estimated phase difference related to a received signal whose received power level output from the smoothing means is greater than a threshold value. The means for improving the vibration displacement calculation accuracy according to claim 1.

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