JP2000283762A - Gyro apparatus for monitoring displacement of construction, ground, etc. - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separately measure the inclination angle and the displacement due to shift, using the same sensor system. SOLUTION: The apparatus comprises an accelerometer 1 having an input shaft parallel to the inclining direction of a surface to be measured, a gyro 2 having an input shaft parallel to the surface to be measured and perpendicular to the input shaft of the accelerometer 1, means for measuring the inclination angle by executing the calculation based on the outputs of the accelerometer 1 and gyro 2, means for correcting the acceleration value outputted from the accelerometer 1 according to the gravitational acceleration component of the inclination angle measured by the inclination measuring means to obtain a horizontal acceleration value, means for measuring the horizontal shift distance by twice integrating the horizontal acceleration value obtained by that means, and means for preventing the divergence of the horizontal shift distance due to errors contained in the acceleration value provided by the shift measuring means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro apparatus for monitoring the displacement of a structure used in civil engineering and construction, etc., a ground or the like. The present invention relates to a gyro device for monitoring displacement of a ground or the like.

[0002]

2. Description of the Related Art In a ground monitoring device for civil engineering or the like,
A gyro is used as an inclinometer for measuring an inclination angle of an inclination measurement surface due to ground movement. The gyro simply embeds a pipe in a hole drilled in the ground and measures the inclination of the pipe.

On the other hand, in a building monitoring apparatus such as an architectural apparatus, for example, an inclinometer for measuring an inclination angle and an acceleration of an inclination measuring surface due to shaking of a bridge through which a train or an automobile passes is used.
Gyros and accelerometers are used.

[0004]

However, in the inclinometer used in the former ground monitoring device, when the entire pipe slides with the ground, it is not detected as a tilt angle. Was not detected as abnormal even if it occurred. In particular, in the shield construction method, the inclinometer as described above is sometimes used to monitor sheet piles that shield the ground.However, when the sheet pile is displaced, the amount of movement is not detected, and the sheet pile is allowed to slide. If the amount exceeds the limit and the seam of the shield is broken, earth and sand, water, etc. may intrude into the inside of the shield and a disaster may occur.

Further, the inclinometer used in the latter building monitoring device cannot measure the movement amount of the bridge and the bridge girder or the movement amount between the bridge and the bridge girder. Although it has a structure that can absorb the displacement even if it moves about several centimeters due to an earthquake or the like, if it exceeds the allowable value, the bridge will fall from the bridge girder. In the past large earthquakes, many bridges fell, causing a great disaster.

The present invention has been made in view of the above circumstances, and provides a gyro apparatus for monitoring a displacement of a structure, a ground or the like, which can separately measure an inclination angle and a displacement due to movement by the same sensor system. The purpose is to do.

[0007]

According to the present invention, in order to achieve the above object, a gyro apparatus for monitoring a displacement of a structure, a ground or the like is constituted by the following means.

The invention according to claim 1 has an accelerometer having an input axis parallel to the tilt direction of the surface to be measured, and an input axis parallel to the surface to be measured and orthogonal to the input axis of the accelerometer. A gyro, an output of the accelerometer, an inclination angle measuring means for executing an operation based on the output of the gyro to measure an inclination angle, and an acceleration value output from the accelerometer is measured by the inclination angle measuring means. Means for obtaining a horizontal acceleration value by correcting the gravitational acceleration component of the tilt angle, a moving amount measuring means for integrating the horizontal acceleration value obtained by this means twice to measure a moving distance in the horizontal direction, Means for preventing the movement distance in the horizontal direction from diverging due to an error included in the acceleration value.

A second aspect of the present invention is a gyro apparatus for monitoring displacement of a structure, a ground, or the like according to the first aspect of the present invention, wherein the means for preventing the divergence of the horizontal movement distance uses a high-pass filter. It was what was.

According to a third aspect of the present invention, in the gyro apparatus for monitoring displacement of a structure, a ground or the like according to the first aspect of the present invention, the means for preventing the divergence of the horizontal moving distance includes an acceleration value or a speed. A predetermined range of values is set as a dead zone.

Therefore, in the gyro apparatus for monitoring a displacement of a structure, a ground or the like according to the first to third aspects of the present invention, a gravitational acceleration component obtained by calculating an output of an accelerometer and measuring a measured inclination angle. , The acceleration due to the horizontal movement is obtained, and this acceleration is integrated twice, so that the amount of movement of the measured object in the axial direction can be measured.

Further, the acceleration caused by the horizontal movement is 2
In the process of consolidation, DC components such as accelerometer bias are removed by a high-pass filter or dead zone, so that the integrated output does not diverge and the displacement can be measured with high accuracy. .

According to a fourth aspect of the present invention, in the gyro apparatus for monitoring a displacement of a structure, a ground or the like according to the first aspect of the present invention, the inclination angle measuring means calculates the inclination angle of the measurement surface from the output of the accelerometer. Calculating means, subtracting means for calculating the difference between the tilt angle and the measured tilt angle, multiplying means for multiplying the difference by a gain, integrating the difference and adding the result to the output of the multiplying means, and the added value And an integrating means for integrating the difference between the gyro and the output of the gyro and outputting the result as a measured inclination angle.

Therefore, in the invention corresponding to claim 4, the inclination angle of the measurement surface is calculated from the output of the accelerometer,
The difference between the tilt angle and the measured tilt angle is multiplied by a gain to obtain a difference between the output of the gyro and the difference is integrated and output as a measured tilt angle. Even in this case, the inclination measurement surface inclination angle can be accurately measured.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a gyro apparatus for monitoring displacement of a structure, ground or the like according to the present invention.

In FIG. 1, reference numeral 1 denotes an accelerometer having an input axis parallel to the tilt direction of the tilt measuring surface to be measured, and 2 denotes an input axis parallel to the tilt measuring surface and orthogonal to the input axis of the accelerometer 1. Gyro having (here optical fiber gyro, F
OG).

Reference numeral 3 denotes a calculation unit to which the output a of the accelerometer 1 and the output dθ / dt of the gyro 2 are input. The calculation unit 3 calculates the movement amount based on the outputs of the accelerometer 1 and the gyro 2. It has a moving amount calculating means, an angular velocity calculating means for obtaining an angular velocity, and an inclination angle calculating means for obtaining an inclination angle.

The accelerometer 1, the gyro device 2, the angular velocity calculating means for obtaining the angular velocity, and the inclination angle calculating means for obtaining the inclination angle have been established as a patent (Japanese Patent No. 2733597).

FIG. 2 is a block diagram showing a detailed configuration example of the arithmetic unit 3 in FIG.

As shown in FIG. 2, the calculating unit 3 includes a calculating means 21 and a first calculating means 21 for calculating the inclination angle θ and the angular velocity.
, A multiplying means 23, a second integrating means 24, and subtracting means 25 and 26, and calculating means 27, subtracting means 28, high-pass filter 2
9, a third integration means 30, a high-pass filter 31, and a fourth integration means 32.

In FIG. 2, when the output a of the accelerometer 1 is input to the calculating means 21, the calculating means 21 calculates the inclination measurement surface from the output a of the accelerometer 1 and the gravitational acceleration g according to equation (1). The inclination angle (temporary inclination angle) θ ′ is calculated, and the inclination angle θ is output.

Θ ′ = sin ⁻¹ (a / g) (1) The tilt angle θ ′ and the measured tilt angle θ output from the first integrating means 22 are input to the subtracting means 25, Difference Δ
θ is output. When the difference Δθ is input to the multiplying means 23, the multiplying means 23 multiplies Δθ by the gain K1.

Further, the difference Δθ between the inclination angle θ ′ output from the subtraction means 25 and the measured inclination angle θ is input to the second integration means 24, and the output of the second integration means 24 and the multiplication means 2
3 are added and input to the subtraction means 26. The second integrating means 24 exemplifies a case in which Δθ is integrated and multiplied by the gain K2.

The subtraction means 23 obtains the difference between the sum of the output of the second integration means 24 and the output of the multiplication means 23 and the output dθ / dt of the gyro 2, and this difference is sent to the first integration means 22. Is entered. The first integrating means 22 integrates the difference (1 / S) and outputs a measured inclination angle θ.

On the other hand, the measured inclination angle θ outputted from the first integrating means 22 is inputted to the calculating means 27. The calculating means 27 calculates a gravitational acceleration component from the measured inclination angle θ and the gravitational acceleration g.

The gravitational acceleration component obtained by the calculating means 27 and the output a of the accelerometer 1 are input to the subtracting means 28 to compensate for the gravitational acceleration component from the output a of the accelerometer 1 and the output is converted to a high-pass filter 29. Through the third integrating means 3
Enter 0. Further, the output of the third integration means 30 is input to the fourth integration means 32 through the high-pass filter 31, and the fourth integration means 32 outputs the movement amount L.

Next, the operation of the gyro device configured as described above will be described.

First, an angular velocity calculating means for obtaining an angular velocity;
The tilt angle calculating means for obtaining the tilt angle will be described.

(A) When there is no change in the oscillating acceleration and the inclination angle of the object to be measured The output angle a of the accelerometer 1 is obtained by the arithmetic means 21 based on the equation (1). Represents an existing tilt angle. Further, since there is no change in the tilt angle, the output dθ / dt of the gyro 2 is zero, and the initial value of the measured tilt angle θ is zero.

At this time, the difference .DELTA..theta. Between the inclination angle .theta. 'Output from the subtraction means 25 and the measured inclination angle .theta. Is negatively fed back to the first integrating means 22 with a gain K1 so that the measured inclination angle .theta. gradually approaching θ ′, and when θ = θ ′, Δθ = 0
And the input to the first integration means 22 becomes zero. That is, θ maintains the value of θ ′.

(B) When the tilt angle changes in the absence of the oscillating acceleration When the tilt angle of the measured surface changes from θ1 to θ2, the output dθ / dt of the gyro 2 indicates the angular velocity from θ1 to θ2. Therefore, the measured inclination angle θ correctly changes from θ1 to θ2. On the other hand, since the inclination angle θ ′ output from the calculating means 21 does not have the oscillating acceleration, it correctly changes from θ1 to θ2.

From the above, it follows that θ = θ ′ and Δ
θ = 0. That is, the output of the multiplying means 23 becomes zero, and no feedback is made to the first integrating means 22. Therefore, the measured tilt angle θ always indicates the correct tilt angle even if the tilt angle changes.

(C) When the swaying acceleration is applied in the swaying inclination direction while the inclination angle of the surface to be measured does not change at θ1, the output dθ / dt of the gyro 2 does not change because the inclination angle does not change.
Is zero.

The output a of the accelerometer 1 is a combination of the inclination component a1 of the gravitational acceleration g and the sway acceleration a1H.
a = a1 + a1H = a1 + Asinωt.

Accordingly, the inclination angle θ ′ is as follows: θ ′ = sin ⁻¹ {(a1 + Asinωt) / g} (2) The maximum value A of the swaying speed aH is generally 1/10 or less of the gravitational acceleration g, that is, A << g.

Therefore, equation (2) can be approximated as equation (3).

Θ ′ ≒ sin ⁻¹ (a1 / g) + tan ⁻¹ {Asinωt / (g ² −a1 ² ) ^1/2 } = θ1 + tan ⁻¹ {Asinωt / (g ² −a1 ² ) ^1/2 } ( 3) The relationship between the tilt angle θ ′ and the measured tilt angle θ is dθ / dt = 0.
It is represented more like FIG. 3 and takes the form of a first-order filter. The time constant is 1 / K1, and the cutoff frequency f0 of this filter is f0 = K1 / 2π.

Therefore, the gain K is set so that the cutoff frequency f0 is sufficiently smaller than the angular frequency ω of the sway acceleration a1H.
If 1 is set, the fluctuation of the tilt angle θ ′ is reduced by the low-pass filter effect and is not output to the measured tilt angle θ. That is, when the two terms on the right side of the above equation (3) decrease, θ ′ ≒ θ1, and the measured tilt angle θ maintains the value of θ ′, indicating the correct tilt angle θ1.

(D) The case where the tilt measurement surface actually fluctuates, and both the change in the tilt angle and the vibration acceleration are present. In this case, the combination of the above-mentioned actions (b) and (c) is obtained. Similarly, the measured tilt angle θ indicates the correct tilt angle.

On the other hand, the difference Δθ between the inclination angle θ ′ output from the subtraction means 25 and the measured inclination angle θ is input to the second integration means 24, and the output of the second integration means 24 and the multiplication means 23
Has a function of automatically estimating and correcting the magnitude of the drift error by adding the output to the subtraction means 26.

Here, the operation will be described. The relationship between the drift error δdθ / dt of the gyro 2 and the measured tilt angle error δθ due to the drift error δdθ / dt can be shown in FIG.

In FIG. 4, δθ is the second integration means 24
And is negatively fed back to the first integrating means 22, so that δθ decreases. When the output of the second integration means 24 becomes equal to δθ / dt, the first integration means 22
Becomes zero, and the output of the second integration means 24 becomes δ
Maintain θ / dt. That is, the second integrating means 24 has estimated the drift error δθ / dt, which is the first error.
The drift error δθ / dt is corrected.

Therefore, since the measured tilt angle error δθ becomes zero, the measured tilt angle θ is equal to the drift error δdθ / gyro 2
It shows the correct tilt angle without being affected by dt.

Next, a description will be given of a movement amount calculation function for obtaining the movement amount.

The output a of the accelerometer 1 and the first integrating means 2
The gravitational acceleration component obtained by calculating the inclination angle θ obtained from 2 by the calculating means 27 is input to the subtracting means 28, and the gravitational acceleration component is corrected from the output a of the accelerometer 1 so that the horizontal movement is obtained. The acceleration at is output. That is, the output a of the accelerometer 1 can be expressed by a = at · cos θ + g · sin θ (3) as is clear from the vector diagram shown in FIG. Here, g is the gravitational acceleration.

From the above equation (3), at = (ag−sin θ) / cos θ (4)

The horizontal acceleration at obtained by the subtraction means 28 is input to a third integration means 30 through a high-pass filter 29, and the output of the third integration means is passed through a high-pass filter 31 to a fourth integration means 32. , The horizontal acceleration at is respectively integrated twice.

As described above, when the horizontal acceleration at is integrated twice, the horizontal displacement L can be found from equation (5).

L = ∫∫ (at) dtdt (5) Here, the third integration means 30 and the fourth integration means 3
If the integration operation is continuously performed in step 2, the error component such as the bias signal of the accelerometer 1 included in the output a of the accelerometer 1 is also integrated together, so that the error increases with time, May diverge.

In the present embodiment, the high-pass filters 29 and 31 are provided before the third integration means 30 and the fourth integration means 32, respectively, so that DC components such as a bias signal of the accelerometer 1 are eliminated. It is cut and the integrated output does not diverge.

FIG. 6 is a time chart showing the acceleration when the high-pass filter is provided, the velocity output from the third integrating means 30, and the displacement obtained from the fourth integrating means 32.

As can be seen from this figure, even if the output of the accelerometer 1 contains a DC component such as a bias signal,
Since the cut is made by passing through the high-pass filters 29 and 31, it is possible to measure the changing moving amount without diverging the measured value of the moving amount.

As described above, in the first embodiment, the accelerometer 1 having the input axis parallel to the tilt direction of the measurement surface of the measured object, and the input axis of the accelerometer 1 parallel to the tilt measurement surface. A gyro 2 having an input axis orthogonal to the axis, and an arithmetic means 21 for calculating the inclination angle θ ′ of the measurement surface from the output a of the accelerometer 1
Subtracting means 25 for calculating the difference between the inclination angle θ 'and the measured inclination angle θ; multiplication means 23 for multiplying the difference by a gain; and integrating the difference and adding the result to the output of the multiplication means. The difference between the obtained value and the output of the gyro 2 is integrated to obtain the measured inclination angle θ.
As a result, even when the tilt measurement surface is fluctuating, the tilt measurement surface tilt angle can be accurately measured.

Further, since the drift error of the gyro 2 is estimated and corrected, the error of the tilt angle caused by the drift error is eliminated, and a highly accurate tilt angle can be obtained.

On the other hand, the output a of the accelerometer 1 is corrected by the gravitational acceleration component obtained by calculating the measured inclination angle θ to obtain the acceleration at due to the horizontal movement.
Since t is integrated by the third integrating means 30 and the integrated output is output by the fourth integrating means 32, the moving amount (moving displacement) L of the measured object in the axial direction can be measured. .

Further, the acceleration at due to the horizontal movement at
Before the third integration means 30 and the fourth integration means 32 are used, DC components such as the bias of the accelerometer 1 are removed by the high-pass filters 29 and 31, so that the integrated output diverges. And the displacement can be measured with high accuracy.

In the first embodiment, the third integrating means 30 and the fourth integrating means 32 are used as the moving amount calculating means.
And the input stages thereof are provided with the high-pass filters 29 and 31, respectively. However, a dead zone may be provided instead of the high-pass filters 29 and 31.

FIG. 7 shows the acceleration when the dead zone is provided and the third acceleration.
The speed output from the integrating means 30, the fourth integrating means 3
6 is a time chart showing the movement displacement obtained from FIG.

As can be seen from this figure, even if the output of the accelerometer 1 contains a DC component such as a bias signal,
By providing the dead zone, the normal acceleration at is within the dead zone, so that the integration result does not diverge. Further, the acceleration value is integrated only when the acceleration exceeds the dead zone, so that the movement amount in that period can be obtained.

The following effects can be obtained by applying the gyro device according to the present invention having such a structure to a ground monitoring device for civil engineering or a building monitoring device for architecture.

That is, when the ground monitoring apparatus monitors a sheet pile that shields the ground by a shield method or the like, the inclination angle and the movement amount can be obtained from the same sensor system. Even if there is an abnormality in the movement amount, it is possible to determine that the sheet pile of the shield method is slipping due to the action of the external pressure or the internal pressure, and to be notified as an abnormal value before the sheet pile is largely inclined. Therefore, evacuation and the like of the worker working inside the shield can be carried out at an early stage, so that a personal injury can be reduced and a great effect on disaster prevention can be obtained.

In a building monitoring apparatus, when monitoring the moving amount of a bridge fixed on a bridge girder in a bridge through which a railway vehicle or an automobile passes, in addition to the inclination angle, the moving amount from a first point is monitored. Can be measured by the same sensor system, and it is possible to determine whether or not the bridge and the bridge girder have been displaced beyond an allowable value by arranging the sensors at appropriate locations. Therefore, when the movement amount of the bridge exceeds the allowable value, it is possible to immediately stop traffic and the like, and a great effect on disaster prevention can be obtained.

[0064]

As described above, according to the present invention, it is possible to provide a gyro apparatus for monitoring a displacement of a structure, a ground or the like, which can separately measure an inclination angle and a displacement due to movement by the same sensor system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a gyro apparatus for monitoring displacement of a structure, a ground or the like according to the present invention.

FIG. 2 is a block diagram showing a detailed configuration example of a calculation unit 3 of FIG.

FIG. 3 is a diagram showing a relationship between a tilt angle θ ′ when a gyro output is zero and a measured tilt angle θ in the embodiment.

FIG. 4 shows a drift error δdθ /
The figure which shows the relationship between dt and measurement inclination-angle error (delta) (theta).

FIG. 5 is a vector diagram showing a relationship among an output of an accelerometer, a gravitational acceleration component, and an acceleration due to horizontal movement in the embodiment.

FIG. 6 is a time chart showing acceleration, velocity, and movement displacement when a high-pass filter is provided in a movement calculation function based on double integration in the embodiment.

FIG. 7 is a time chart showing acceleration, velocity, and movement displacement when a dead zone is provided in the movement calculation function by double integration in the embodiment.

[Explanation of symbols]

 1: Accelerometer 2: Gyro 3: Operation part 21, 27: Operation means 22: First integration means 23: Multiplication means 24: Second integration means 25, 26, 28: Subtraction means 29, 31: High-pass filter 30 : Third integration means 32: Fourth integration means

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Junichi Ito 3-1-1 Musashino, Akishima City, Tokyo Japan Aviation Electronics Industry Co., Ltd. (72) Inventor Kiichiro Taguchi 2-3-18 Fujisawa, Fujisawa City, Kanagawa Kanto Airways Within Keiki Co., Ltd. (72) Inventor Takashi Ogawara 66-2 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa F-term (reference) 2F076 BA15 BB09 BD00 BE05 2F105 AA10 BB08 BB17

Claims (4)

[Claims] 1. An accelerometer having an input axis parallel to a tilt direction of a surface to be measured, a gyro having an input axis parallel to the surface to be measured and orthogonal to an input axis of the accelerometer, An inclination angle measuring means for performing an operation based on the output and the output of the gyro to measure an inclination angle, and an acceleration value output from the accelerometer is calculated by a gravitational acceleration component of the inclination angle measured by the inclination angle measuring means. Means for correcting to obtain a horizontal acceleration value, movement amount measuring means for integrating the horizontal acceleration value obtained by this means twice to measure a horizontal movement distance, and said movement amount measurement means provided in said movement amount measurement means. Means for preventing divergence of the horizontal movement distance due to an error included in the acceleration value,
A gyro device for monitoring displacement of the ground. 2. The gyro apparatus according to claim 1, wherein said means for preventing the divergence of the horizontal movement distance is a high-pass filter. Gyro device for displacement monitoring. 3. The gyro device according to claim 1, wherein
The means for preventing the divergence of the horizontal movement distance has a predetermined range of an acceleration value or a speed value as a dead zone. 4. A gyro apparatus for monitoring displacement of a structure, a ground or the like according to claim 1, wherein the inclination angle measuring means calculates an inclination angle of a measurement surface from an output of the accelerometer, and the inclination angle and the measured inclination angle. Subtraction means for calculating a difference between the difference, a gain means for multiplying the difference by a gain, and the difference is integrated and added to an output of the multiplication means, and a difference between the added value and an output of the gyro is integrated. A gyro device for monitoring displacement of a structure, a ground or the like, which comprises an integrating means for outputting the measured inclination angle.