JPH0712562A - Bend measuring method of hole - Google Patents

Abstract

PURPOSE:To obtain a measuring method in which the bend state of a vertical or nearly vertical hole is measured with high accuracy, continuously and in a short time. CONSTITUTION:The measuring method is a method in which the bend of a hole 12 in the vertical direction or the nearly vertical direction is measured by a probe 18 on which an accelerometer 20 and a gyro 22 have been mounted. Individual inclinations theta at the entrance 12I and the end 12E of the hole 12 are measured by the accelerometer 20, and an inclination between them is measured continuously by the gyro 22. The measuring method is constituted in such a way that the difference between the inclination value of the end 12E on the basis of the continuously measured value and the inclination value, of the end 12E of the hole 12, which has been measured by the accelerometer 20 is regarded as the drift of the gyro 22 having a definite drift rate within the continuous measuring time and that the continuously measured value is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a bend in a hole (including a pipeline) by a probe equipped with an accelerometer and a gyro. Therefore, the 3-axis accelerometer and 3
This also includes the case of using a probe equipped with an inertial sensor having a three-axis gyro that measures each angular velocity around the axis.

[0002]

2. Description of the Related Art Inclinometers have generally been used to measure the bending of holes. When measuring with this inclinometer, the inclinometer must be stopped.

[0003]

However, since the measurement is stopped at the time of measurement, it is possible to measure only discretely and it is difficult to measure the continuous curved shape of the hole. In addition, there is also a problem that it takes a lot of measurement time to follow the procedure of moving and measuring discretely.

Therefore, an object of the present invention is to provide a measuring method for measuring a bent state of a hole accurately and continuously in a short time.

[0005]

In view of the above-mentioned object, the present invention is a method for measuring the bending of a hole by a probe equipped with an accelerometer and a gyro, wherein each inclination at the entrance and the end of the hole is measured by the acceleration. A gyro, and the difference between the slope value at the end of the hole and the slope value at the end of the hole measured by the accelerometer is measured by the gyro. There is provided a hole bending measuring method characterized in that the continuous measurement value is corrected as a drift of the gyro having a constant drift rate within a continuous measurement time.

[0006]

The accelerometer measures two points, the entrance and the end of the hole, and continuously measures the gyro from the entrance to the end. This gyro is accompanied by an unavoidable measurement error called a gyro drift, but since the measurement is completed in a short time in normal measurement, this drift rate can be regarded as almost unchanged and constant. On the other hand, if there is no drift, the measured value of the tilt angle at the end of the hole by the accelerometer should match the tilt value at the end of the gyro, and if there is a difference, it can be regarded as the amount of the drift. If this drift is divided by the time required for measurement, the drift rate can be calculated. Correcting the measurement value with this drift rate enables highly accurate hole bending measurement, and because it is a gyro measurement, it is continuously short. It is possible to measure in time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail based on the embodiments shown in the accompanying drawings. FIG. 1 shows an apparatus for carrying out the hole bending measuring method according to the present invention, and a portion indicated by A is an enlarged view. A hole 12 is formed in the ground 10 in a vertical direction or a direction close to the vertical direction, and an inlet 12I is located on the surface of the ground and a terminal 12E thereof is located in the ground.

A probe 1 having a wheel 24 and an accelerometer 20 and a gyro 22 mounted therein is provided in the hole 12.
8 runs. Orthogonal three axes X, Y and Z composed of two horizontal axes X and Y and a vertical axis Z and a rotation angle φ around each axis.
θ and ψ are defined as shown in FIG. It travels in the hole 12 while being pulled by the tow rope 16 wound around the reel 14 on the surface of the earth, and the bent state of the hole 12 is continuously measured by the gyro 22. At the beginning and end of the measurement, the probe 18 is stopped and the accelerometer 20 is used to measure the hole 1
Measure the tilt angle of 2. Below, for the sake of simplicity, the hole 12
Among the bends, the tilted state that is the rotation angle θ around the Y axis will be described.

The results of this measurement are shown in FIG. The horizontal axis represents time t, and the vertical axis represents the hole bending angle θ. Curve θ1 is gyro 2
2 is a continuous measurement result of the hole 12 by 2, and the measurement time t
A point PI of = 0 and a point PE of measurement time t = t0 are measurement results at the entrance 12I and the end 12E of the hole 12 by the accelerometer 20. At the entrance 12I of the hole 12, the measurement results of the gyro 22 and the accelerometer 20 match, but the end 12
At E, there is a difference by the angle θD.

This is because the gyro 22 is accompanied by a measurement error called a gyro drift. Since the measurement by the accelerometer 20 does not involve such an error, it is rational to correct the measurement result by the gyro 22 at the end 12E of the hole 12 to match the measurement result (point PE) by the accelerometer 20. is there.

Here, FIG. 3 shows drift caused by the gyro 22. As described above, since the drift rate may be considered to be constant, the time t required for measurement by the gyro 22 is t.
The drift rate can be calculated by dividing the angle difference θD by 0. Therefore, the drift at each time t is the origin O
And a straight line θ2 passing through the point (t0, θD). When the drift straight line θ2 is subtracted from the measurement result curve θ1 by the gyro 22 in FIG. 2, a highly accurate corrected curve θ12 of the hole bending state after the correction of the gyro drift is obtained.

The traveling time t of the probe 18 in the hole 12 and the traveling distance 1 correspond one-to-one with the moving speed of the tow rope 16. That is, l = f (t). Therefore, the curve indicating the hole bending angle θ (curve θ12 in FIG. 2) is the hole 12
It is also possible to obtain the travel distance 1 of the above as the horizontal axis. on the other hand,
Referring to a minute triangle in which each side in FIG. 1 is dZ, dX, dl, dX = dl · sin θ. Therefore, X = (integral symbol) sin θdl, and the hole bending angle θ and the traveling distance l
This integration can be performed since the relationship with and is obtained as a curve similar to that of FIG. 2 as described above. As a result, a curve HC 'as shown in FIG. 4 is obtained. 10 is the end 1 of the hole 12
It is the length (distance traveled) up to 2E.

Further, FIG. 5 shows the Cartesian coordinates X, (Y,) of FIG.
The hole bending curve HC by Z is shown. Referring to the small triangle in FIG. 1, dZ = dl · cos θ and Z =
(Integral symbol) cos θdl. Since the relationship between the hole bending angle θ and the traveling distance 1 is obtained as a curve similar to that shown in FIG. 2 as described above, this integration can be executed. as a result,
The curve HC of FIG. 5 is obtained. Z0 is the inlet 12I of the hole 12
To the end 12E (Z-axis direction).

For simplicity, the rotation angle θ around the Y-axis has been described above.
Although only the inclination of the above is described, the inclination of the rotation angle φ around the other axis can be measured in the same manner, and further, the rotation angle ψ can be measured by using the inertial sensor. You can know. In the square hole (or conduit) 12 of the cross section where the rolling of the probe 18 (the change of the azimuth angle ψ in FIG. 1) does not occur, the probe 18
Need only have a gyro 22 for two axes except the rotation angle ψ and an accelerometer 20 for two axes.

[0015]

As is apparent from the above description, according to the present invention, since the bending state of the hole in the vertical direction or the direction close to the vertical direction is measured by the gyro, the measurement can be continuously performed in a short time.
Moreover, since the inclination of the entrance and the end of the hole is measured by the accelerometer, the drift of the gyro can be corrected by comparison with this measurement data, and it is possible to provide a method that can measure the continuous inclination state with high accuracy in a short time. Becomes

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an implementation of a measuring method according to the present invention.

FIG. 2 is an explanatory diagram of a measuring method of the present invention.

FIG. 3 is an explanatory diagram of a gyro drift.

FIG. 4 is a diagram showing a hole bending state with respect to the length coordinate (1) of the hole as a result of performing the measuring method of FIG. 1.

5 is a diagram showing a hole bending state with respect to a vertical position (Z) of the hole, which is a result of performing the measuring method of FIG.

[Explanation of symbols]

 10 underground 12 hole (pipe) 12E terminal 12I inlet 14 reel 16 traction rope 18 probe 20 accelerometer 22 gyro

Claims (1)

[Claims] 1. A method for measuring the bending of a hole by a probe equipped with an accelerometer and a gyro, wherein each inclination at the entrance and the end of the hole is measured by the accelerometer, and the inclination between them is continuously measured by the gyro. The difference between the inclination value of the terminal end based on this continuous measurement value and the inclination value of the terminal end of the hole measured by the accelerometer,
A hole bending measuring method, wherein the continuous measurement value is corrected as a drift of the gyro having a constant drift rate within the continuous measurement time.