JP2019191093A - Displacement analyzer, GNSS positioning analyzer, and displacement analysis method - Google Patents

Abstract

To provide a displacement analyzer with which it is possible to provide still more useful information pertaining to a position.SOLUTION: An analyzer 3 comprises: a baseline analysis unit 9a for finding observation data by GNSS positioning data acquired in a first cycle from a reference measuring device 2r and a measuring device 2 arranged at a displacement measuring point; a sensor output value acquisition unit 9b for acquiring a sensor output value outputted in a second cycle shorter than the first cycle by a movement detection sensor that moves integrally with a GNSS antenna 8 of the measuring device 2 and outputting one of displacement, speed and acceleration; a first displacement function acquisition unit 21 for finding a first measured value from the observation data; a second displacement function acquisition unit 22 for finding a second measured value from a sensor output value that is the same physical quantity as the first measured value; a correction processing unit 23 for correcting the sensor output value and outputting a sensor output value after correction so that the first and the second measured values at a prescribed timing match each other; and a composite position acquisition unit 15 for finding the displacement of a past displacement measuring point from the measured data and the sensor output value after correction.SELECTED DRAWING: Figure 1

Description

  The present invention mainly relates to a displacement analyzer that analyzes displacement based on a record of GNSS positioning performed in the past.

  Conventionally, a positioning system for monitoring the movement of a moving body is known. Patent document 1 discloses this kind of positioning system.

  Patent Document 1 calculates a position of an aircraft, a GPS receiver, an accelerometer that measures the acceleration of the aircraft, a signal synchronization unit that corrects the measured acceleration value so as to be synchronized with the measurement cycle of the GPS receiver, and A state quantity calculation unit is disclosed.

  In this measurement apparatus, the position of the aircraft is obtained by integrating the corrected acceleration data by the state quantity calculation unit in a cycle in which the signal synchronization unit performs the synchronization process.

JP 7-239236 A

  In the configuration of Patent Document 1, since the priority is given to knowing the position of the device itself in real time, the accuracy of the acquired position is often not so severe. On the other hand, a configuration that can provide more useful information regarding the position is required even when the displacement of the measurement point is precisely calculated after a while after performing GNSS observation, such as analysis of ground displacement, for example. .

  The present invention has been made in view of the above circumstances, and a main object thereof is to realize a displacement analyzer that can provide more useful information regarding the position.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to a first aspect of the present invention, a displacement analyzer having the following configuration is provided. In other words, the displacement analyzer includes an observation data calculation unit, a first calculation unit, a sensor output value acquisition unit, a second calculation unit, a sensor output value correction unit, and a displacement amount calculation unit. The observation data calculation unit is acquired at a predetermined first period by GNSS positioning data acquired at a predetermined first period by a GNSS antenna disposed at a reference measurement point, and at a predetermined first period by a GNSS antenna disposed at a displacement measurement point. Obtain observation data from GNSS positioning data. The first calculation unit obtains a first measurement value from the observation data. The sensor output value acquisition unit moves integrally with the GNSS antenna, and the movement detection sensor that outputs any one of displacement, speed, and acceleration outputs a sensor output value output in a second period shorter than the first period. To get. The second calculation unit obtains a second measurement value that is the same physical quantity as the first measurement value from the sensor output value. The sensor output value correction unit corrects the sensor output value and outputs a corrected sensor output value so that the first measurement value at a predetermined timing matches the second measurement value at the predetermined timing. The displacement amount calculation unit obtains the displacement of the past displacement measurement point based on the observation data and the corrected sensor output value.

  Thereby, based on the GNSS positioning performed in the predetermined first period and the measurement by the movement detection sensor performed in the second period shorter than the first period, the position at the time interval shorter than the GNSS positioning interval is acquired. can do.

  In the displacement analyzer, it is preferable that the predetermined timing is a positioning timing of the first period.

  Accordingly, the sensor output value is corrected so that the first measurement value and the second measurement value at the timing of GNSS positioning coincide with each other, so that the position at a time interval shorter than the GNSS positioning interval can be obtained with high accuracy.

  In the displacement analyzer, the first calculation unit obtains a first function of time and the first measurement value, and the second calculation unit calculates a second function of time and the second measurement value. Preferably, the sensor output value correction unit corrects the sensor output value so that the first function and the second function match.

  Accordingly, the sensor output value is corrected so that the first function and the second function expressed so as to interpolate the position at the timing between the positioning timing and the positioning timing match each other, so that the time shorter than the GNSS positioning interval Positions at intervals can be acquired with high accuracy.

  In the displacement analyzer, the sensor output value correction unit differentiates an error curve that is a difference between the second function and the first function, and uses the output value error curve obtained by the differentiation. It is preferable to correct the output value of the movement detection sensor.

  Thereby, it can correct | amend correctly so that the output of a movement detection sensor may correspond with the result of GNSS positioning.

  In the displacement analyzer, the first measurement value and the second measurement value are preferably displacement amounts.

  As a result, the sensor output value can be corrected using the first measurement value and the second measurement value, which are the displacement amounts.

  In the displacement analyzer, the movement detection sensor can detect speed or acceleration, and the second calculation unit can obtain the second measurement value by integrating the output value of the movement detection sensor. Is preferred.

  Accordingly, the second measurement value can be easily obtained by the process of integrating the speed or acceleration.

  In the displacement analyzer, the first measurement value and the second measurement value are preferably speed or acceleration.

  Accordingly, the sensor output value can be corrected using the first measurement value and the second measurement value, which are speeds or accelerations and are the same physical quantity.

  In the displacement analysis apparatus, it is preferable that the first calculation unit obtains the first measurement value by differentiating a displacement amount indicated by the observation data.

  Thus, the first measurement value can be easily obtained by the process of differentiating the position variation.

  In the displacement analyzer, the first calculation unit obtains a first function of time and the first measurement value that is velocity or acceleration, and the second calculation unit calculates time, velocity, or acceleration. A second function of the second measurement value is obtained, and the sensor output value correction unit uses the output value error curve that is a difference between the second function and the first function to move the movement It is preferable to correct the output value of the detection sensor.

  Thereby, it can correct | amend correctly so that the output of a movement detection sensor may correspond with the result of GNSS positioning.

  According to the 2nd viewpoint of this invention, the displacement analyzer of the following structures is provided. In other words, the displacement analysis apparatus includes a first calculation unit, a sensor output value acquisition unit, a second calculation unit, a sensor output value correction unit, and a displacement amount calculation unit. The first calculation unit obtains a first measurement value from GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a displacement measurement point. The sensor output value acquisition unit moves integrally with the GNSS antenna, and the movement detection sensor that outputs any one of displacement, speed, and acceleration outputs a sensor output value output in a second period shorter than the first period. To get. The second calculation unit obtains a second measurement value that is the same physical quantity as the first measurement value from the sensor output value. The sensor output value correction unit corrects the sensor output value and outputs a corrected sensor output value so that the first measurement value at a predetermined timing matches the second measurement value at the predetermined timing. The displacement amount calculation unit obtains the displacement of the past displacement measurement point based on the GNSS positioning data and the corrected sensor output value.

  Thereby, based on the GNSS positioning performed in the predetermined first period and the measurement by the movement detection sensor performed in the second period shorter than the first period, the position at the time interval shorter than the GNSS positioning interval is acquired. can do.

  The displacement analyzer includes an offset correction unit that corrects an output value of the movement detection sensor so as to eliminate an offset in the change when a sudden change of a predetermined value or more is detected in the second measurement value. It is preferable.

  Thereby, the position detection accuracy can be kept good.

  The displacement analyzer preferably includes a temperature drift correction unit that corrects the output value of the movement detection sensor based on the output value of the temperature sensor that detects the temperature of the movement detection sensor.

  Thereby, the position detection accuracy can be kept good.

  The displacement analyzer preferably includes a filter processing unit that performs low-pass filter processing on the output value of the movement detection sensor.

  Thereby, the influence of high frequency noise can be avoided and the accuracy of position detection can be kept good.

  In the displacement analyzer, it is preferable that the filter processing unit performs the low-pass filter processing in both the forward direction and the reverse direction on the output value of the movement detection sensor input in time order.

  As a result, the delays in the waveform of the output value caused by the filter processing cancel each other, so that it is possible to prevent the waveform from being shifted in the time axis direction.

  According to the 3rd viewpoint of this invention, the GNSS positioning analysis apparatus of the following structures is provided. That is, this GNSS positioning analysis apparatus includes the displacement analysis apparatus and the measurement apparatus. The measurement device performs GNSS positioning. The measurement device includes a GNSS receiver and the movement detection sensor. The GNSS receiver performs the GNSS positioning.

  Thereby, the position by a time interval shorter than a GNSS positioning interval is acquirable by measuring by a GNSS positioning and a movement detection sensor, and analyzing with a displacement analyzer later.

  The GNSS positioning analyzer is preferably configured as follows. That is, at least one of the measurement device and the displacement analysis device includes an output value conversion unit. The output value conversion unit represents the output value of the movement detection sensor with the coordinate axis based on the relationship between the direction of the detection axis of the movement detection sensor and the direction of the coordinate axis of the position information acquired by the GNSS positioning. Convert as follows.

  Thereby, since a measuring device can be installed without minding the direction of a movement detection sensor, workability | operativity can be improved.

  In the GNSS positioning analyzer, the output value conversion unit may change between the detection value of the movement detection sensor and the position indicated by the position information during the positioning timing for performing the GNSS positioning. Based on the above, it is preferable to obtain the relationship between the direction of the detection axis of the movement detection sensor and the direction of the coordinate axis of the position information by calculation.

  Thus, the relationship between the direction of the detection axis of the movement detection sensor and the direction of the coordinate axis of the position information can be obtained by calculation without requiring a special sensor.

  In the GNSS positioning analyzer, detection by the movement detection sensor is performed at a timing that is synchronized with the positioning timing for performing the GNSS positioning and that is divided into two or more equally between the positioning timing and the next positioning timing. It is preferable.

  As a result, no deviation occurs between the detection timing of the movement detection sensor and the timing of GNSS positioning, so that the error can be reduced and the calculation process for eliminating the timing deviation can be omitted.

  The GNSS positioning analyzer is preferably configured as follows. That is, the measurement device includes a clock generation unit that generates a clock signal synchronized with the GNSS time based on a signal output from the GNSS receiver. Acquisition of the output value of the movement detection sensor is performed at a timing based on the clock signal generated by the clock generation unit.

  Thereby, the shift | offset | difference between the detection timing by a movement detection sensor and the timing of GNSS positioning can be eliminated with a simple configuration.

  The GNSS positioning analyzer is preferably configured as follows. That is, the clock generation unit includes an oscillator capable of controlling the frequency. The clock generation unit generates the clock signal by the oscillator controlled to be synchronized with a timing signal input from the GNSS receiver in synchronization with GNSS time. The clock generator controls to maintain the frequency of the oscillator when the timing signal is obtained when the timing signal is not input.

  Thereby, even when the reception condition of the GNSS radio wave is bad, the detection timing by the movement detection sensor can be stabilized.

  According to a fourth aspect of the present invention, the following displacement analysis method is provided. That is, observation is performed from GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a reference measurement point and GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a displacement measurement point. Ask for data. A first measurement value is obtained from the observation data. A movement detection sensor that moves integrally with the GNSS antenna and outputs any one of displacement, velocity, and acceleration acquires a sensor output value output in a second period shorter than the first period. A second measurement value that is the same physical quantity as the first measurement value is obtained from the sensor output value. The sensor output value is corrected so that the first measurement value matches the second measurement value. Based on the observation data and the corrected sensor output value, the displacement of the displacement measurement point in the past is acquired.

The block diagram which shows the structure of an analyzer in the ground observation system which concerns on 1st Embodiment. The block diagram which shows the structure of a measuring device etc. FIG. The graph which shows the displacement based on the output value of the acceleration sensor before correction | amendment by the temperature drift correction | amendment part, and after correction | amendment. The graph which shows the displacement based on the output value of the acceleration sensor before correction | amendment by the offset correction part, and after correction | amendment. The graph explaining the correction | amendment which a sensor drift correction | amendment part performs. The graph which shows the displacement based on the output value of the acceleration sensor before correction | amendment by the sensor drift correction | amendment part, and after correction | amendment. The block diagram which shows the structure of an analyzer in the ground observation system which concerns on 2nd Embodiment. The graph explaining the correction | amendment by a sensor drift correction | amendment part. The block diagram which shows the structure of a measuring apparatus etc. in the ground observation system which concerns on 3rd Embodiment. The block diagram which shows the structure of an analyzer. The block diagram which shows the structure of an analyzer in the ground observation system which concerns on 4th Embodiment. The block diagram which shows the measuring device which concerns on a modification.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an analysis device 3 in the ground observation system 1 according to the first embodiment. FIG. 2 is a block diagram showing the configuration of the measuring device 2 and the like.

  A ground observation system (GNSS positioning analysis device) 1 shown in FIG. 1 is a device that monitors crustal movements, landslides, and the like. The ground observation system 1 includes a measurement device 2, a reference measurement device 2r, and an analysis device (displacement analysis device) 3.

  The measuring device 2 is installed at each of a plurality of measurement points determined on the ground to be observed. Each of the plurality of measuring devices 2 observes GNSS radio waves and acquires information necessary for positioning.

  The ground observation system 1 of this embodiment measures the displacement of a measurement point precisely by performing well-known GNSS interference positioning. For this purpose, the ground observation system 1 includes a reference measurement device 2r installed at a reference point whose position is known in addition to the measurement device 2 described above.

  The analysis device 3 can communicate with the measurement device 2 and the reference measurement device 2r, and can acquire observation information and the like acquired when the measurement device 2 and the reference measurement device 2r each receive a GNSS radio wave. The analysis device 3 generates and outputs information related to the displacement of the ground by analyzing the information acquired by the measurement device 2.

  The measuring device 2 will be described with reference to FIG. Each of the plurality of measuring devices 2 has the same configuration, and each measuring device 2 includes a GNSS receiver 4, a GNSS antenna 8, an acceleration sensor (movement detection sensor) 5, a temperature sensor 6, and a control unit. And a memory 7.

  The GNSS receiver 4 receives GNSS radio waves from at least four GNSS satellites via the GNSS antenna 8. The GNSS receiver 4 outputs observation information (for example, baseline analysis data including information on the carrier phase of the GNSS radio wave) obtained by analyzing the GNSS radio wave to the control unit memory 7.

  The GNSS antenna 8 is an antenna that receives a GNSS radio wave, and is fixed to an appropriate position of the measurement device 2. The GNSS antenna 8 is electrically connected to the GNSS receiver 4.

  The acceleration sensor 5 is fixed at an appropriate position of the measuring device 2. Therefore, for example, when the measurement apparatus 2 moves due to displacement in the ground, the acceleration sensor 5 moves integrally with the GNSS antenna 8.

  The acceleration sensor 5 detects acceleration. In the present embodiment, the acceleration sensor 5 is configured as a three-axis acceleration sensor having three detection axes orthogonal to each other. The acceleration sensor 5 acquires the acceleration generated in the acceleration sensor 5 in the directions of the three detection axes, and outputs them to the control unit memory 7 as output values. Hereinafter, the output value of the acceleration sensor 5 may be simply referred to as an acceleration value.

  The temperature sensor 6 is disposed at an appropriate position of the measuring device 2 and detects the temperature of the acceleration sensor 5 or its surroundings. Although details will be described later, the temperature detected by the temperature sensor 6 is used to correct a temperature drift occurring in the detection value of the acceleration sensor 5 in the analysis device 3. The temperature sensor 6 outputs the acquired temperature to the control unit memory 7 as an output value. Hereinafter, the output value of the temperature sensor 6 may be simply referred to as a temperature value.

  The control unit memory 7 functions as a buffer memory that temporarily stores observation information output from the GNSS receiver 4, information on the output value of the acceleration sensor 5, and information on the output value of the temperature sensor 6. Observation information, acceleration values, and temperature value information stored in the control unit memory 7 are transmitted to the analysis device 3 via a communication unit (not shown).

  Observation information, acceleration value, and temperature value information are accumulated to some extent in the control unit memory 7 and then output to the analysis device 3. Correspondingly, the analysis by the analysis device 3 is not a real-time process, but a batch process that collectively processes records for a predetermined past time. The frequency at which the analysis process is performed is arbitrary, and can be, for example, every hour or every few minutes. There may be provided an information relay device that receives and collects the observation information transmitted by the plurality of measuring devices 2 and records them together and outputs the records to the analyzing device 3.

  The reference measuring device 2r has a configuration corresponding to that obtained by omitting the acceleration sensor 5 and the temperature sensor 6 from the measuring device 2. The reference measurement device 2r receives the GNSS radio wave via the GNSS antenna 8 in the same manner as the measurement device 2, and transmits the observation information output by the GNSS receiver 4 to the analysis device 3 via a communication unit (not shown). Since it is not assumed that the ground of the reference point is displaced, the reference measuring device 2r installed at the reference point includes an acceleration sensor 5 and a temperature sensor 6 for correcting the detection value of the acceleration sensor 5. Is not provided.

  The analysis device 3 is configured as a server device installed in a data analysis facility physically separated from the measurement device 2 and the reference measurement device 2r, for example. The analysis device 3 includes a communication unit (not shown) and can receive information transmitted by the measurement device 2 and the reference measurement device 2r. This communication unit can use, for example, a LAN or a WAN. Communication may be performed by wire or may be performed by radio.

  As shown in FIG. 1, the analysis device 3 includes a baseline analysis unit (observation data calculation unit) 9a, a sensor output value acquisition unit 9b, a temperature drift correction unit 10, an offset correction unit 11, and a sensor drift correction unit. 12, a first filter processing unit 13, a displacement amount acquisition unit 14, a combined position acquisition unit (displacement amount calculation unit) 15, and a second filter processing unit 16.

  Specifically, the analysis device 3 is configured as a known computer and includes a CPU, a ROM, a RAM, and the like. The ROM stores a program for realizing the displacement analysis method of the present invention. By the cooperation of the above hardware and software, the computer is converted into a baseline analysis unit 9a, a temperature drift correction unit 10, an offset correction unit 11, a sensor drift correction unit 12, a first filter processing unit 13, and a displacement amount acquisition unit. 14, the combined position acquisition unit 15, the second filter processing unit 16, and the like.

  The baseline analysis unit 9a performs baseline analysis based on observation information acquired and recorded in the past (for example, several minutes ago) by the GNSS receiver 4 included in each of the measurement device 2 and the reference measurement device 2r. Since baseline analysis is well known in GNSS interferometric positioning, detailed description is omitted. Thereby, the baseline vector which is a vector (in other words, a vector from the reference measurement device 2r to the measurement device 2) heading from the reference point to the measurement point at the time of GNSS positioning can be obtained. Since the position of the reference point is known as described above, information on the position of the measurement point (position of the measurement device 2) can be obtained based on the obtained baseline vector.

  In the following description, information on the position of the measuring device 2 obtained by GNSS positioning (interference positioning in this embodiment) may be referred to as position information.

  The baseline analysis unit 9a performs the baseline analysis for each observation information acquired from the measurement device 2 and the reference measurement device 2r (in other words, for each recording of GNSS positioning acquired in a predetermined first period). Thereby, the position of the past measuring device 2 is calculated | required one after another. The baseline analysis unit 9a outputs the obtained position information as observation data to an information storage server that is an external device, and outputs it to a sensor drift correction unit 12 and a combined position acquisition unit 15 described later.

  In the ground observation system 1 of the present embodiment, the baseline analysis unit 9a outputs the position of the measuring device 2 every second as the position information. In the interference positioning, the time interval for obtaining the position can be further shortened. However, due to the nature of GNSS positioning, etc., the baseline analysis unit 9a can only acquire the position of the measuring device 2 that is the shortest and several tens of minutes per second, and cannot determine the position at a shorter time interval. .

  On the other hand, the acceleration sensor 5 shown in FIG. 2 can detect acceleration at a frequency of, for example, thousands to tens of thousands of times per second. Therefore, when based on the output value of the acceleration sensor 5, the position of the measuring device 2 can be obtained with a sufficiently good SN ratio even at a shorter time interval than the above, for example, every hundredth of a second. That is, the acceleration sensor 5 can obtain the position of the measuring device 2 in a second period shorter than the first period. From this, the detection of the displacement using the acceleration sensor 5 is suitable for detecting a displacement (for example, vibration of a structure) on the order of 100 Hz, for example.

  On the other hand, from the viewpoint of measurement accuracy, when the displacement is obtained by accumulating the output values of the acceleration sensor 5, the error increases cumulatively with the passage of time, and the reliability decreases. On the other hand, GNSS positioning can acquire a position with stable accuracy. Thus, the detection of the displacement by GNSS positioning and the detection of the displacement by the acceleration sensor have properties that complement each other.

  The sensor output value acquisition unit 9 b acquires the sensor output value from the control unit memory 7 of the measuring device 2 and outputs the acquired sensor output value to the temperature drift correction unit 10.

  1 is measured by the acceleration sensor 5 when the above-described GNSS positioning has been performed in the past, and the temperature is calculated from the output value (the acceleration value) based on the recorded acceleration output value. Make corrections to remove the effects of drift. The temperature drift correction unit 10 includes a temperature drift correction amount acquisition unit 17 and a correction processing unit 18.

  The temperature drift correction amount acquisition unit 17 measures the temperature by measuring the temperature sensor 6 almost simultaneously with the measurement of the acceleration sensor 5 and substituting the recorded temperature output value (the temperature value) into a predetermined temperature drift function. Get the drift correction amount. The temperature drift function defines the relationship between the temperature of the acceleration sensor 5 and the amount of drift that occurs in the output value of the acceleration sensor 5 at the temperature, and is obtained in advance by experiments or the like. This temperature drift function is stored in a storage unit (not shown) included in the temperature drift correction amount acquisition unit 17. The temperature drift correction amount acquisition unit 17 calculates a temperature drift correction amount for canceling the drift amount and outputs the obtained temperature drift correction amount to the temperature drift correction unit 10.

  The correction processing unit 18 corrects the acceleration value based on the temperature drift correction amount obtained by the temperature drift correction amount acquisition unit 17. As a correction method, for example, the temperature drift correction amount may be added to or subtracted from the acceleration value. Thereby, the correction | amendment process part 18 can acquire the acceleration which removed the influence of the temperature drift. The correction processing unit 18 (temperature drift correction unit 10) outputs the obtained acceleration value to the offset correction unit 11.

  The effect of the temperature drift correction unit 10 will be described with reference to FIG. FIG. 3 is a graph showing displacement based on the output value of the acceleration sensor 5 before and after correction by the temperature drift correction unit 10.

  In FIG. 3, the acceleration sensor 5 is simply vibrated at a constant cycle in a direction parallel to one of the three detection axes, and at the same time the temperature is changed at a predetermined cycle larger than the cycle of vibration. The displacement based on the acceleration value is compared with the displacement based on the acceleration value corrected by the temperature drift correction unit 10. The horizontal axis of the graph is time, and the vertical axis is displacement or temperature.

  The graph of FIG. 3 is an experimental result by simulation calculation. The displacement based on the acceleration value can be obtained by further integrating the velocity obtained by integrating the acceleration value. The calculation for obtaining the displacement from the acceleration value substantially corresponds to the second order integration of the acceleration value. The displacement changes discontinuously in the vicinity of 0.3 on the horizontal axis, and after that, the displacement error becomes considerably large. This is a simulation of the offset described later that occurs in the displacement based on the acceleration value. It is.

  As shown in FIG. 3, it can be seen that, when the temperature drift correction is performed on the acceleration value, the undulation of the displacement at a period substantially equal to the period of the temperature change can be reduced satisfactorily as compared with the case where the acceleration value is not performed.

  The offset correction unit 11 in FIG. 1 detects a shift (offset) that suddenly occurs in the displacement obtained by integrating the acceleration value in which the temperature drift is corrected, and corrects this offset. As a cause of the occurrence of this offset, for example, it is considered that some physical change has occurred in the acceleration sensor 5.

  The offset correction unit 11 detects whether or not an offset has occurred in the displacement by monitoring the change in the displacement. More specifically, each time the acceleration value is input from the temperature drift correction unit 10, the offset correction unit 11 is between the displacement obtained from the current acceleration value and the displacement obtained from the previous acceleration value. Calculate the difference. The difference between the displacements can be regarded as a value obtained by differentiating the displacement once, and can also be regarded as a value obtained by integrating the acceleration once. The offset correction unit 11 determines that an offset has occurred when the obtained difference exceeds a predetermined threshold.

  When an offset is detected, the offset correction unit 11 calculates a difference in displacement (in other words, speed) before and after such a sudden change, and an acceleration necessary for canceling this difference. The correction value is calculated to correct the acceleration value. The correction value can be obtained by a known differential calculation. Thereby, the influence of offset can be removed from the acceleration value. The offset correction unit 11 outputs the corrected acceleration value to the sensor drift correction unit 12.

  Although the above-described offset may occur a plurality of times, the offset correction unit 11 performs correction for canceling the offset on the acceleration value every time the offset is detected.

  Processing performed by the offset correction unit 11 will be described with reference to FIG. FIG. 4 is a graph showing displacement based on the output value of the acceleration sensor 5 before and after correction by the offset correction unit 11.

  FIG. 4 shows a displacement based on the acceleration value after the temperature drift correction shown in FIG. 3 and a value obtained by differentiating the displacement. However, in order to show the change of the differentiated value in an easy-to-understand manner, the value obtained by squaring the differentiated value is plotted in the graph of FIG.

  Since the displacement changes little by little during normal times, the displacement change amount (in other words, the differential value) is a value near zero. At a timing near 0.3 on the horizontal axis, the displacement based on the acceleration value after the temperature drift correction increases discontinuously. Along with this, the amount of change in the displacement increases rapidly and exceeds a predetermined threshold. Thereby, the offset correction unit 11 detects the occurrence of the offset.

  The offset correction unit 11 that has detected the offset corrects the acceleration value so as to cancel the offset amount of the displacement. As shown in FIG. 4, the displacement based on the acceleration value after the offset correction eliminates the discontinuous change of the value as compared with the case without the offset correction, and the error can be considerably reduced.

  The sensor drift correction unit 12 in FIG. 1 corrects a drift generated in the acceleration value based on the displacement of the GNSS receiver 4 output from the baseline analysis unit 9a and the acceleration value output from the offset correction unit 11. .

  There are various causes of the drift (hereinafter sometimes referred to as sensor drift) generated in the output value of the acceleration sensor 5, but the influence of the drift caused by the temperature change has already been removed by the temperature drift correction unit 10. Yes. Therefore, the temperature drift is not included in the sensor drift to be corrected by the sensor drift correction unit 12.

  The sensor drift correction unit 12 includes a first displacement function acquisition unit (first calculation unit) 21, a second displacement function acquisition unit (second calculation unit) 22, a correction processing unit (sensor output value correction unit) 23, Is provided.

  The first displacement function acquisition unit 21 performs a curve fitting on the positions indicated by the plurality of position information input from the baseline analysis unit 9a, and approximates the transition of the position (hereinafter referred to as a first displacement function). ). This first displacement function represents a displacement amount (first measured value) based on GNSS positioning.

  The above curve fitting will be specifically described with reference to FIGS. FIG. 5 is a graph illustrating the correction performed by the sensor drift correction unit 12. FIG. 6 is a graph showing displacement based on the output value of the acceleration sensor 5 before and after correction by the sensor drift correction unit 12.

  It is assumed that the baseline analysis unit 9a outputs position information regarding a timing arbitrarily selected from past positioning timings where observation information is recorded (hereinafter also referred to as reference positioning timing). Hereinafter, the position indicated by the position information is referred to as a reference position. As shown in the graph of FIG. 5, the horizontal axis represents the elapsed time from the reference positioning timing, and the position indicated by the position information varies in each coordinate axis from the reference position (for example, the longitude direction, the latitude direction, and the altitude direction). Consider a coordinate plane whose vertical axis is the variation in each. By plotting the relationship between elapsed time and position fluctuation on this coordinate plane and performing curve fitting using, for example, a polynomial curve, an approximate curve that approximates the transition of the position information can be obtained. This approximate curve corresponds to the first displacement function. The curve fitting can be performed using, for example, a least square method.

  Since the position information is represented by positions on three coordinate axes, the approximate curve can be obtained for each of the three coordinate axes (longitude direction, latitude direction, and altitude direction). Since the position should match the reference position at the reference positioning timing (in other words, the position variation should be zero), the zero-order term of the curve used for curve fitting is zero.

  As described above, in the ground observation system 1 of the present embodiment, the time interval of the positioning timing is 1 second. In this regard, in the present embodiment, since the first displacement function representing the change in position indicated by the position information is obtained as a curve function, position interpolation between the positioning timing and the positioning timing can be realized.

  The first displacement function acquisition unit 21 outputs the acquired first displacement function to the correction processing unit 23.

  The second displacement function acquisition unit 22 performs curve fitting on the acceleration value output from the offset correction unit 11 to obtain a function that approximates the acceleration value. Thereafter, a second function (hereinafter sometimes referred to as a second displacement function) representing the displacement of the measuring device 2 is obtained by second-order integration of the function. The second displacement function represents a displacement detection amount (second measurement value) that is a displacement amount based on detection by the acceleration sensor 5.

  Hereinafter, this curve fitting will be specifically described. As shown in the graph of FIG. 5, consider a coordinate plane in which the elapsed time from the reference positioning timing is the horizontal axis, and the output values for each of the three detection axes of the acceleration sensor 5 are the vertical axes. It is assumed that the direction of each detection axis of the acceleration sensor 5 coincides with the coordinate axis of the position information in GNSS positioning. By plotting the relationship between the elapsed time and the output value (acceleration value) of the acceleration sensor 5 on this coordinate plane and performing curve fitting using, for example, a polynomial curve, an approximate curve that approximates the transition of the acceleration value can be obtained. it can. Hereinafter, the curve function obtained by this curve fitting may be referred to as an acceleration function. The curve fitting can be performed using, for example, a least square method.

  The second displacement function acquisition unit 22 obtains a second displacement function by performing second order integration on the obtained acceleration function. Similarly to the first displacement function, the acceleration function and the second displacement function can be obtained for each of the three coordinate axes of the position information. The second displacement function acquisition unit 22 outputs the obtained second displacement function to the correction processing unit 23.

  Based on the difference between the first displacement function and the second displacement function, the correction processing unit 23 corrects the acceleration value so as to cancel the difference.

  This will be specifically described below. The correction processing unit 23 subtracts the second displacement function input from the second displacement function acquisition unit 22 from the first displacement function input from the first displacement function acquisition unit 21. FIG. 5 shows a function that is an error curve thus obtained (hereinafter may be referred to as “difference function”). This difference function represents an error between displacement due to GNSS positioning using the GNSS receiver 4 and displacement due to acceleration detected by the acceleration sensor 5.

  The correction processing unit 23 acquires a plurality of plots indicating the relationship between the elapsed time and the error by substituting some appropriate elapsed time values into the difference function. And the correction | amendment process part 23 calculates | requires the function showing the error between displacement by performing curve fitting with respect to the said some plot. Hereinafter, this function may be referred to as a displacement error function. The curve of the displacement error function substantially matches the curve shape of the difference function.

  In the present embodiment, a curve of a polynomial that is not very high order, for example, a cubic polynomial is used for curve fitting when obtaining a displacement error function. As a result, a curve that is substantially the same as the difference function can be expressed in a simple form, and the process of calculating the second-order derivative described later is simplified.

  The correction processing unit 23 performs second-order differentiation on the displacement error function and converts the function into a function (output value error curve) indicating an acceleration error. Hereinafter, this function may be referred to as an acceleration error function. The correction processing unit 23 obtains an acceleration error by substituting the elapsed time into the acceleration error function, and adds the obtained acceleration error to the acceleration value to obtain a corrected acceleration value.

  In this way, the sensor drift correction unit 12 can correct the output value of the acceleration sensor 5. The sensor drift correction unit 12 outputs the corrected acceleration value to the first filter processing unit 13.

  In the graph of FIG. 5, curves corresponding to the first displacement function, the second displacement function, the difference function (displacement error function), and the acceleration error function are drawn, and the acceleration value after correction by the sensor drift correction unit 12 is drawn. Is plotted. However, in FIG. 5, the corrected acceleration value is not the output value input to the sensor drift correction unit 12, but an acceleration error function is added to the acceleration function obtained by curve fitting the output value. It is assumed that

  In this specification, “curve” is synonymous with a function representing the curve. A second-order derivative of a displacement error function curve (displacement error curve) corresponds to an acceleration error function curve (acceleration error curve, output value error curve). Although only one curve is shown in FIG. 5, each actual curve exists for each of the three coordinate axes of the position information.

  Further, in FIG. 5 and FIG. 6, the results of calculating the displacement based on the acceleration value corrected by the sensor drift correcting unit 12 are plotted. Referring to the graph of FIG. 5, the displacement based on the corrected acceleration value agrees well with the position variation obtained by the GNSS positioning as compared with the displacement based on the acceleration value before correction (second displacement function). I understand that. Furthermore, it can be seen from the graph of FIG. 6 that the displacement based on the acceleration value corrected by the sensor drift correcting unit 12 is in good agreement with the displacement actually applied to the acceleration sensor 5.

  The timing target for obtaining the displacement error function may be, for example, from the first positioning timing appropriately selected from the past positioning timing to the subsequent second positioning timing. The length between the first positioning timing and the second positioning timing may be one time of the GNSS positioning interval, or may be two times or more. By correcting the acceleration value so that the displacement detection amount in the corresponding period coincides with the fluctuation of the position information between the first positioning timing and the second positioning timing, the same effect as described above can be obtained. Obtainable.

  The first filter processing unit 13 in FIG. 1 performs an appropriate low-pass filter process on the acceleration value output from the correction processing unit 23 (sensor drift correction unit 12) to remove high-frequency noise. As the low-pass filter, a known filter such as an IIR filter, an FIR filter, a section curve fit, or a Kalman filter can be used. Thereby, since the high frequency component contained in the acceleration value is suppressed, it can be expected that the displacement error shown in FIG. 6 is further reduced.

  The first filter processing unit 13 preferably performs the same low-pass filter process in the reverse direction after performing the low-pass filter process in the forward direction on the acceleration values input in time order. By performing filter processing in opposite directions in this way, delays that occur in the waveform of the acceleration value due to the filter processing cancel each other, so that deviation of the waveform in the time axis direction can be prevented. The first filter processing unit 13 outputs the filtered acceleration value to the information storage server and also to the displacement amount acquisition unit 14.

  The displacement amount acquisition unit 14 obtains the displacement amount by second-order integration of the acceleration value input from the first filter processing unit 13. The displacement amount acquisition unit 14 outputs the obtained displacement amount value to the information storage server and also outputs it to the composite position acquisition unit 15.

  The combined position acquisition unit 15 combines the position indicated by the position information obtained from the baseline analysis unit 9a and the displacement amount input from the displacement amount acquisition unit 14, thereby indicating the position information indicating the position of the measuring device 2. Is calculated. Thereby, the positional information by GNSS positioning and the displacement amount by the acceleration sensor 5 can be integrated. The composite position acquisition unit 15 outputs the obtained position to the second filter processing unit 16.

  The second filter processing unit 16 performs low-pass filter processing on the position acquired from the combined position acquisition unit 15 in the same manner as the first filter processing unit 13 to remove high frequency noise. Similarly to the first filter processing unit 13, the second filter processing unit 16 preferably performs the same low-pass filter processing in the forward direction and the reverse direction. The second filter processing unit 16 outputs the obtained position as position information to the information storage server.

  In the analysis device 3, the position information D1 output from the baseline analysis unit 9a is, for example, the position of the measurement device 2 every second. On the other hand, the displacement amount D2 output from the displacement amount acquisition unit 14 and the position information D3 output from the second filter processing unit 16 are, for example, displacements or positions of the measuring device 2 every hundredth of a second. Can do. Further, the acceleration CA output from the first filter processing unit 13 can also be an acceleration per hundredths of a second, for example. Thus, the analysis device 3 can acquire a change in the position of the measurement device 2 at a considerably short time interval, and thus is suitable for use in analyzing fine vibrations and the like.

  As described above, the analysis device 3 of the present embodiment includes the baseline analysis unit 9a, the sensor output value acquisition unit 9b, the first displacement function acquisition unit 21, the second displacement function acquisition unit 22, and the correction process. Unit 23 and composite position acquisition unit 15. The baseline analysis unit 9a includes the GNSS positioning data acquired in the first cycle by the reference measurement device 2r arranged at the reference measurement point, and the GNSS positioning acquired in the first cycle by the measurement device 2 arranged at the displacement measurement point. Obtain observation data from the data. The sensor output value acquisition unit 9b moves integrally with the GNSS antenna 8 of the measurement device 2, and acquires the acceleration value output by the acceleration sensor 5 that outputs acceleration in a second period shorter than the first period. The first displacement function acquisition unit 21 obtains a first measurement value from the observation data. The second displacement function acquisition unit 22 obtains a second measurement value that is the same physical quantity as the first measurement value from the acceleration value. The correction processing unit 23 corrects the acceleration value so that the first measurement value at a predetermined timing matches the second measurement value at the predetermined timing, and outputs a corrected sensor output value. The composite position acquisition unit 15 obtains the displacement of the past displacement measurement point based on the observation data and the corrected sensor output value.

  Thereby, based on the GNSS positioning performed in the predetermined first period and the measurement by the acceleration sensor 5 performed in the second period shorter than the first period, the position at the time interval shorter than the GNSS positioning interval is acquired. can do.

  Next, a second embodiment will be described with reference to FIG. FIG. 7 is a block diagram showing a configuration of the analysis device 3x in the ground observation system 1x according to the second embodiment. FIG. 8 is a graph illustrating correction by the sensor drift correction unit 12x. In the following description of the present embodiment, members that are the same as or similar to those of the above-described embodiment are denoted by the same reference numerals in the drawings, and description thereof may be omitted.

  In the ground observation system 1x of the second embodiment shown in FIG. 7, the sensor drift correction unit 12x included in the analysis device 3x includes a first acceleration function acquisition unit (first calculation unit) 21x and a second acceleration function acquisition unit (first 2 calculation unit) 22x and a correction processing unit (sensor output value correction unit) 23x.

  The first acceleration function acquisition unit 21x obtains an acceleration function (first acceleration function) representing a change in position based on a plurality of pieces of position information input from the baseline analysis unit 9a.

  Specifically, the first acceleration function acquisition unit 21x first approximates the transition of the position as shown in the graph of FIG. 8 by performing curve fitting with respect to the position indicated by the plurality of input position information. Find the displacement function to be used. In the above curve fitting, for example, a power function can be used. Furthermore, the first acceleration function acquisition unit 21x obtains the first acceleration function by performing second order differentiation of the displacement function. The first acceleration function acquisition unit 21x outputs the obtained first acceleration function to the correction processing unit 23x in FIG.

  The second acceleration function acquisition unit 22x performs curve fitting on the acceleration value input from the offset correction unit 11, and obtains a second acceleration function that is a function approximating the acceleration value as shown in FIG. The acceleration value that is the target of curve fitting is the acceleration value (corresponding to the acceleration value measured by the acceleration sensor 5 at the same time as the GNSS positioning related to the position information curve-fitted by the first acceleration function acquisition unit 21x). Sensor output value). In this curve fitting, for example, a curve corresponding to the second derivative of the curve used for approximation by the first acceleration function acquisition unit 21x can be used. The second acceleration function acquisition unit 22x outputs the obtained second acceleration function to the correction processing unit 23x in FIG.

  The correction processing unit 23x obtains a difference between the first acceleration function obtained from the first acceleration function acquisition unit 21x and the second acceleration function obtained from the second acceleration function acquisition unit 22x. In the present embodiment, this difference function may be referred to as an acceleration error function. FIG. 8 shows curves of the acceleration error function (acceleration error curve, output value error curve). The correction processing unit 23x obtains an acceleration error by substituting the elapsed time into the acceleration error function, and adds the obtained acceleration error to the acceleration value to obtain a corrected acceleration value. The correction processing unit 23x (sensor drift correction unit 12x) outputs the corrected acceleration value to the first filter processing unit 13.

  In the graph of FIG. 8, curves corresponding to the first acceleration function, the second acceleration function, and the acceleration error function are drawn, and the acceleration values corrected by the sensor drift correction unit 12x are plotted.

  Further, FIG. 8 plots the result of calculating the displacement based on the acceleration value corrected by the sensor drift correcting unit 12x. According to the graph of FIG. 8, it can be seen that also in the present embodiment, the displacement based on the corrected acceleration value is in good agreement with the position variation obtained by the GNSS positioning.

  As described above, the analysis device 3x of the present embodiment includes the baseline analysis unit 9a, the sensor output value acquisition unit 9b, the second acceleration function acquisition unit 22x, the first acceleration function acquisition unit 21x, and the correction process. Unit 23 and composite position acquisition unit 15. The baseline analysis unit 9a obtains observation data from the GNSS positioning data acquired in the first period. The sensor output value acquisition unit 9b acquires the sensor output value output by the acceleration sensor 5 in the second period. The second acceleration function acquisition unit 22x obtains an acceleration value that is an output value at the time of the GNSS positioning from a record of an output value measured by the acceleration sensor 5 at the past GNSS positioning. The first acceleration function acquisition unit 21x acquires the acceleration at which the position indicated by the position information varies. The correction processing unit 23x corrects the output value of the acceleration sensor 5 acquired from the recording so that the acceleration value matches the acceleration acquired by the first displacement function acquisition unit 21. Based on the position information and the output value of the acceleration sensor 5 corrected by the correction processing unit 23, the combined position acquisition unit 15 obtains the displacement of the past displacement measurement point.

  Thereby, based on the GNSS positioning performed in the predetermined first period and the measurement by the acceleration sensor 5 performed in the second period shorter than the first period, the position at the time interval shorter than the GNSS positioning interval is acquired. can do.

  Next, a third embodiment will be described. FIG. 9 is a block diagram showing the configuration of the measuring device 2y in the ground observation system 1y according to the third embodiment. FIG. 10 is a block diagram illustrating a configuration of the analysis apparatus 3y.

  In the ground observation system 1y according to the third embodiment, the measuring device 2y includes an orientation sensor 28 as shown in FIG. 9, and the analysis device 3y includes an inclination angle acquisition unit 29 and an output value conversion unit 30 as shown in FIG. It differs from the above-mentioned embodiment by providing.

  The azimuth sensor 28 of FIG. 9 is configured as a magnetic azimuth sensor that acquires the azimuth by detecting geomagnetism, and is fixed at an appropriate position of the measuring device 2y. The direction sensor 28 outputs the detected direction to the control unit memory 7. The output value of the azimuth sensor 28 is once stored in the control unit memory 7 and then transmitted to the analysis device 3.

  In the present embodiment, the acceleration value output from the temperature drift correction unit 10 is input to the tilt angle acquisition unit 29 in the analysis device 3y of FIG.

  The inclination angle acquisition unit 29 obtains the inclination angle of the acceleration sensor 5 with respect to the vertical direction based on the acceleration value. Specifically, using the fact that the gravitational acceleration is always directed to the center of the earth, the acceleration sensor 5 detects the inclination of the acceleration sensor 5 based on the acceleration values at the three detection axes on which the gravitational acceleration is detected. It can be obtained by a calculation formula.

  Based on the inclination angle of the acceleration sensor 5 acquired by the inclination angle acquisition unit 29 and the output value of the azimuth sensor 28, the output value conversion unit 30 determines the direction of the detection axis of the acceleration sensor 5 and the coordinate axis of the position information. Find the relationship between direction. Thereafter, the output value conversion unit 30 converts the output value of the acceleration sensor 5 based on the relationship of the axis directions so that the coordinate axis of the position information is used as a reference. Since the calculation for this conversion is well-known, description is abbreviate | omitted.

  In FIG. 10, the temperature drift correction unit 10 and the sensor drift correction unit 12 are simply illustrated, but each configuration is the same as that in the first embodiment.

  In the configuration of the present embodiment, since the detection axis of the acceleration sensor 5 does not have to be aligned with the coordinate axis of the position information, the installation work at the measurement point of the measurement device 2y is simplified.

  Next, a fourth embodiment will be described. FIG. 11 is a block diagram illustrating a configuration of the analysis device 3z in the ground observation system 1z according to the fourth embodiment.

  The analysis device 3z of the present embodiment shown in FIG. 11 is replaced with a forced tilt detection unit 31, an azimuth / tilt angle acquisition unit 32, instead of the tilt angle acquisition unit 29 and the output value conversion unit 30 of the third embodiment. Is provided.

  For example, immediately after the measurement device 2 is installed at the measurement point and the GNSS positioning is started, the forced inclination detection unit 31 records that the operator has artificially inclined the measurement device 2 as a result of the GNSS interference positioning. If so, this inclination is detected from the output of the baseline analysis unit 9a. The forced inclination detection unit 31 outputs to the azimuth / tilt angle acquisition unit 32 whether or not there is a forced inclination (detection result).

  When the forced tilt of the measuring device 2 is detected in the forced tilt detection unit 31, the azimuth / tilt angle acquisition unit 32 changes the position information due to the GNSS positioning at this time, the detection value of the acceleration sensor 5, and The relationship between the direction of the detection axis of the acceleration sensor 5 and the direction of the coordinate axis of the position information that minimizes the difference between the two is calculated. This calculation can be performed based on a geometrical relationship by utilizing the fact that the positional relationship between the acceleration sensor 5 and the GNSS antenna 8 is maintained constant during the tilting process. The azimuth / tilt angle acquisition unit 32 outputs information related to the direction of the detection axis of the acceleration sensor 5 to the output value conversion unit 30.

  According to this configuration, the relationship between the detection axis of the acceleration sensor 5 and the direction of the coordinate axis of the position information can be obtained without providing the azimuth sensor 28 in the measuring device 2 as in the third embodiment. it can. For this reason, in this embodiment, the orientation sensor 28 is not provided in the measuring device 2. Thereby, reduction of cost and simplification of a structure are realizable.

  Next, a modification of the above embodiment will be described. FIG. 12 is a block diagram illustrating a measurement device 2v according to a modification. In the description of this modification, the same or similar members as those in the above-described embodiment may be denoted by the same reference numerals in the drawings, and description thereof may be omitted.

  A measurement device 2v of this modification shown in FIG. 12 includes a clock generation unit 41 and an AD converter 44 in addition to the GNSS receiver 4, the acceleration sensor 5, the temperature sensor 6, and the control unit memory 7 described above.

  The GNSS receiver 4 outputs baseline analysis data obtained by GNSS positioning to the control unit memory 7. Further, the GNSS receiver 4 outputs GNSS time information obtained by GNSS positioning to the first time counter 46. Further, the GNSS receiver 4 outputs a reference timing signal (timing signal), which is a pulse signal once per second synchronized with the GNSS second, to the clock generation unit 41.

  The clock generation unit 41 includes a PLL circuit 42 and a frequency control oscillator 43.

  A clock signal generated by the frequency controlled oscillator 43 and a reference timing signal output by the GNSS receiver 4 are input to the PLL circuit 42. The PLL circuit 42 outputs a control signal to the frequency control oscillator 43 to control so that the phase of the timing obtained by appropriately dividing the input clock signal matches the phase of the reference timing signal from the GNSS receiver 4. . Thereby, the frequency controlled oscillator 43 can generate a clock signal synchronized with the reference timing signal.

  The frequency control oscillator 43 oscillates at a frequency (for example, 10 MHz) corresponding to the control signal from the PLL circuit 42 and outputs a clock signal. The clock signal generated by the frequency controlled oscillator 43 is input to the PLL circuit 42 and also input to the AD converter 44 and the second time counter 47.

  The AD converter 44 samples the acceleration sensor 5 and the temperature sensor 6 at an appropriate sampling frequency to obtain respective output values. The sampling timing is determined so as to be synchronized with the timing at which GNSS positioning is performed and to equally divide between the positioning timing and the next positioning timing into a plurality.

  A clock signal synchronized with the reference timing signal is supplied from the frequency controlled oscillator 43 (clock generation unit 41) to the AD converter 44. Therefore, by determining the timing at which the AD converter 44 performs sampling to acquire the output value with reference to the clock signal, the sampling timing and the GNSS positioning timing can be easily and accurately synchronized. The AD converter 44 outputs the output value of the sampled acceleration sensor 5 and the output value of the temperature sensor 6 to the control unit memory 7.

  With the above configuration, the output value of the acceleration sensor 5 and the output value of the temperature sensor 6 are sampled by the AD converter 44 at the timing when the phase is aligned (coherent) with respect to the GNSS positioning timing, and the values of the time counters 46 and 47 are sampled. At the same time, it can be stored in the control unit memory 7. Accordingly, since it is possible to eliminate the deviation between the acceleration acquisition timing and the GNSS positioning timing, it is possible to prevent a decrease in accuracy based on the time deviation. Further, since processing such as interpolation that takes time deviation into account is unnecessary, calculation can be simplified.

  The temperature sensor 6 outputs the detected temperature to the PLL circuit 42 in addition to the AD converter 44. The PLL circuit 42 keeps the frequency of the clock signal generated by the frequency controlled oscillator 43 constant without the reference timing signal when it becomes impossible to acquire the reference timing signal from the GNSS receiver 4 for some reason such as deterioration of radio wave reception conditions. Try to keep (holdover). In the holdover state, the PLL circuit 42 generates a control signal so as to cancel the temperature drift of the frequency controlled oscillator 43 based on the temperature input from the temperature sensor 6. Thereby, even when the reception of the GNSS radio wave is not good, the acceleration value and the like can be acquired at a timing well synchronized with the timing of the GNSS positioning.

  The measuring device 2 includes a first time counter 46 and a second time counter 47. The first time counter 46 functions as a high-order counter and outputs a count value corresponding to the GNSS time information input from the GNSS receiver 4 to the control unit memory 7. The second time counter 47 functions as a low-order counter, and outputs a count value obtained by counting the clock signals input from the frequency control oscillator 43 to the control unit memory 7.

  The first time counter 46 is a second counter, and the second time counter 47 is a second counter. Since the clock signal input to the second time counter 47 is synchronized with the reference timing signal, the upper digit count value and the lower digit count value do not contradict each other. The control unit memory 7 stores the sampling result of the output value of the acceleration sensor 5 or the like in association with the time represented by the two time counters 46 and 47.

  The preferred embodiments and modifications of the present invention have been described above, but the above configuration can be modified as follows, for example.

  In the measurement apparatus 2 of the first embodiment, a displacement sensor or a speed sensor can be changed to include a movement detection sensor instead of the acceleration sensor 5. In the measurement apparatus 2 of the second embodiment, a speed sensor can be used instead of the acceleration sensor 5.

  The analysis device 3 is configured to include both the sensor drift correction unit 12 described in the first embodiment and the sensor drift correction unit 12x described in the second embodiment, and there is little error due to curve fitting, for example. The correction value may be selected to correct the acceleration value.

  Both the third embodiment and the fourth embodiment may be combined with the configuration of the second embodiment instead of the first embodiment.

  The acceleration CA output by the analysis device 3 may be a value obtained by second-order differentiation of the output of the second filter processing unit 16 instead of the value output by the first filter processing unit 13.

  The analysis device 3 may output the speed. In this case, the speed may be a value obtained by integrating the value output from the first filter processing unit 13 or may be a value obtained by differentiating the value output from the second filter processing unit 16. The analysis device 3 may be included in the reference measurement device 2r or the measurement device 2.

  The GNSS interference positioning may be performed by a virtual reference point method (VRS). In this case, the installation of the reference measurement device 2r can be omitted.

  Further, when the positioning is performed by the high-accuracy single positioning method (PPP) instead of the interference positioning, the installation of the reference measuring device 2r can be omitted. In this case, the baseline analysis unit 9 a of the analysis device 3 is omitted, and the result of the single positioning is directly input to the sensor drift correction unit 12 and the combined position acquisition unit 15.

  A GNSS radio wave transmitted from the quasi-zenith satellite may be used for the GNSS positioning. In the present invention, the term “GNSS positioning” includes a case where a quasi-zenith satellite system (QZSS) is used.

  The displacement analyzer and the GNSS positioning analyzer of the present invention are not limited to the ground, and can be used, for example, to analyze the displacement of various structures.

1 Ground observation system (GNSS positioning analyzer)
2 Measurement device 3 Analysis device (Displacement analysis device)
5 Acceleration sensor (movement detection sensor)
8 GNSS antenna 9a Baseline analysis unit (observation data calculation unit)
9b Sensor output value acquisition unit 15 Composite position acquisition unit (displacement amount calculation unit)
21 1st displacement function acquisition part (1st calculation part)
22 Second displacement function acquisition unit (second calculation unit)
23 Correction processing unit (sensor output value correction unit)

Claims (21)

Observation data from GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a reference measurement point and GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a displacement measurement point An observation data calculation unit for
A first calculation unit for obtaining a first measurement value from the observation data;
A sensor output value acquisition unit that acquires a sensor output value output in a second period shorter than the first period, by a movement detection sensor that moves integrally with the GNSS antenna and outputs any one of displacement, speed, and acceleration. When,
A second calculation unit that obtains a second measurement value that is the same physical quantity as the first measurement value from the sensor output value;
A sensor output value correction unit that corrects the sensor output value and outputs a corrected sensor output value so that the first measurement value at a predetermined timing matches the second measurement value at the predetermined timing;
Based on the observation data and the corrected sensor output value, a displacement amount calculation unit for obtaining a displacement of the displacement measurement point in the past,
A displacement analysis apparatus comprising: The displacement analyzer according to claim 1,
The displacement analyzer according to claim 1, wherein the predetermined timing is a positioning timing of the first period. The displacement analyzer according to claim 1 or 2,
The first calculation unit obtains a first function of time and the first measurement value,
The second calculation unit obtains a second function of time and the second measurement value,
The sensor output value correcting unit corrects the sensor output value so that the first function matches the second function. The displacement analyzer according to claim 3,
The sensor output value correction unit differentiates an error curve that is a difference between the second function and the first function, and uses an output value error curve obtained by the differentiation to calculate an output value of the movement detection sensor. A displacement analyzer characterized by correcting. The displacement analyzer according to any one of claims 1 to 4,
The displacement analyzer is characterized in that the first measurement value and the second measurement value are displacement amounts. The displacement analyzer according to any one of claims 1 to 5,
The movement detection sensor detects speed or acceleration,
The second analysis unit obtains the second measurement value by integrating the output value of the movement detection sensor. The displacement analyzer according to any one of claims 1 to 3,
The displacement analyzer according to claim 1, wherein the first measurement value and the second measurement value are velocity or acceleration. The displacement analyzer according to claim 7,
The first calculation unit obtains the first measurement value by differentiating a displacement amount indicated by the observation data. The displacement analyzer according to claim 7 or 8,
The first calculation unit obtains a first function of time and the first measurement value that is speed or acceleration;
The second calculation unit obtains a second function of time and the second measurement value that is speed or acceleration,
The sensor output value correction unit corrects the output value of the movement detection sensor using an output value error curve that is a difference between the second function and the first function. . A first calculation unit for obtaining a first measurement value from GNSS positioning data acquired at a predetermined first period by a GNSS antenna disposed at a displacement measurement point;
A sensor output value acquisition unit that acquires a sensor output value output in a second period shorter than the first period, by a movement detection sensor that moves integrally with the GNSS antenna and outputs any one of displacement, speed, and acceleration. When,
A second calculation unit that obtains a second measurement value that is the same physical quantity as the first measurement value from the sensor output value;
A sensor output value correction unit that corrects the sensor output value and outputs a corrected sensor output value so that the first measurement value at a predetermined timing matches the second measurement value at the predetermined timing;
Based on the GNSS positioning data and the corrected sensor output value, a displacement amount calculation unit for obtaining a displacement of the displacement measurement point in the past,
A displacement analysis apparatus comprising: The displacement analyzer according to any one of claims 1 to 10,
A displacement analyzer comprising an offset correction unit that corrects an output value of the movement detection sensor so as to eliminate an offset in the change when a sudden change of a predetermined value or more is detected in the second measurement value. . The displacement analyzer according to any one of claims 1 to 11,
A displacement analysis apparatus comprising: a temperature drift correction unit that corrects an output value of the movement detection sensor based on an output value of a temperature sensor that detects the temperature of the movement detection sensor. The displacement analyzer according to any one of claims 1 to 12,
A displacement analysis apparatus comprising a filter processing unit that performs low-pass filter processing on an output value of the movement detection sensor. The displacement analyzer according to claim 13,
The displacement analysis apparatus characterized in that the filter processing unit performs the low-pass filter processing in both the forward direction and the reverse direction on the output values of the movement detection sensor input in time order. The displacement analyzer according to any one of claims 1 to 14,
A measuring device for performing GNSS positioning;
With
The measuring device is
A GNSS receiver for performing the GNSS positioning;
The movement detection sensor;
A GNSS positioning analysis apparatus comprising: A GNSS positioning analyzer according to claim 15,
At least one of the measurement device and the displacement analyzer includes an output value conversion unit,
The output value conversion unit represents the output value of the movement detection sensor with the coordinate axis based on the relationship between the direction of the detection axis of the movement detection sensor and the direction of the coordinate axis of the position information acquired by the GNSS positioning. GNSS positioning analyzer characterized by converting as follows. A GNSS positioning analyzer according to claim 16,
The output value conversion unit is configured to detect the movement based on a detection value of the movement detection sensor during a positioning timing at which the GNSS positioning is performed and a change in the position indicated by the position information between the positioning timings. A GNSS positioning analysis apparatus characterized in that a relationship between a direction of a detection axis of a sensor and a direction of a coordinate axis of the position information is obtained by calculation. A GNSS positioning analyzer according to any one of claims 15 to 17,
The GNSS positioning analyzer is characterized in that the detection by the movement detection sensor is performed at a timing that is synchronized with the positioning timing for performing the GNSS positioning and is equally divided into two or more between the positioning timing and the next positioning timing. . A GNSS positioning analyzer according to claim 18,
The measurement apparatus includes a clock generation unit that generates a clock signal synchronized with the GNSS time based on a signal output from the GNSS receiver.
The GNSS positioning analyzer is characterized in that the output value of the movement detection sensor is acquired at a timing based on the clock signal generated by the clock generation unit. The GNSS positioning analyzer according to claim 19,
The clock generation unit includes an oscillator capable of controlling the frequency,
The clock generation unit generates the clock signal by the oscillator controlled to be synchronized with a timing signal input from the GNSS receiver in synchronization with GNSS time;
The GNSS positioning analyzer, wherein the clock generator controls to maintain the frequency of the oscillator when the timing signal is obtained when the timing signal is not input. Observation data is obtained from GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a reference measurement point and GNSS positioning data acquired at a predetermined first period by a GNSS antenna arranged at a displacement measurement point. Seeking
A first measurement value is obtained from the observation data,
A movement detection sensor that moves integrally with the GNSS antenna and outputs any one of displacement, velocity, and acceleration acquires a sensor output value output in a second period shorter than the first period,
A second measurement value that is the same physical quantity as the first measurement value is obtained from the sensor output value;
Correcting the sensor output value so that the first measurement value and the second measurement value match,
A displacement analysis method characterized in that a displacement of the displacement measurement point in the past is acquired based on the observation data and the corrected sensor output value.

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