JP3384463B2 - Pipeline displacement measurement device using inertial sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus for measuring a displacement of a pipeline from a reference position using an inertial sensor having an accelerometer and a gyroscope. . Therefore, it can be used for measurement of the deformation state of the ground in civil engineering work. [0002] Conventionally, in order to monitor the deformation state of the ground or the like under construction, a pipe for measurement is buried in the ground.
The amount of displacement of this line from the initial reference position is measured by various devices. In this measurement, a method of measuring the amount of displacement using an inertial sensor has recently been developed. Regarding this inertial sensor, one of the applicants
Patent application No. 4-11 dated April 14, 1992 by the applicant
No. 9600, "Hole Bending Measurement Apparatus and Hole Bending Measurement Method" has a detailed description. This measurement method is performed by running an inertial sensor on a measurement target pipeline. [0003] In this case, however, there is some gap between the inner surface of the pipeline to be measured and the casing of the inertial sensor and its wheels. In contrast,
It is also conceivable to eliminate the gap between the inner surface of the pipeline and the casing or wheels of the inertial sensor by the spring support. However, when a very long traction cable is used to pull the casing of the inertial sensor, the length of the long cable extending from the end of the casing to the take-up reel hangs due to its weight. [0004] For this reason, the casing of the inertial sensor is pulled downward by the weight of the pulling cable connected to the end of the casing of the inertial sensor, and travels in the pipeline while being inclined. This is the same when the wheels and the like are supported by springs. [0005] When the duct is bent, the traction cable changes the direction of the traction first, so that a traction force is applied to the casing of the rear inertial sensor in a direction different from the traveling direction of the casing. Therefore, the casing which is still traveling on a straight pipeline tends to be pulled in the left-right direction or the like, and is not necessarily pulled straight along the pipeline. [0006] As described above, a traction force acts on the casing in each direction, which causes pitching and yawing.
Since the amount of this jump appears in the measurement result, there is a problem that the displacement amount of the pipe to be measured cannot be measured correctly. Therefore, an object of the present invention is to provide a measuring device capable of measuring the displacement of a pipe to be measured with high accuracy. SUMMARY OF THE INVENTION In view of the above-mentioned object, the present invention is a displacement measuring device for measuring a displacement of a pipeline relative to a reference position by an inertial sensor running on the pipeline,
A traveling body disposed in front of the casing of the inertial sensor in the traveling direction and capable of traveling along the pipeline; and a traveling body disposed between the traveling body and the casing of the inertial sensor and connecting the traveling body and the casing. to a freely connecting body of the connecting way bend along with pulling the casing by the running forward of the traveling body, is connected to the traveling member comprises a cable for pulling the running body, the inertial Sensor casing
A long cable such as the cable above
Provided is an apparatus for measuring the amount of displacement of a pipeline using an inertial sensor characterized in that no cables are connected . The object to which the traction cable is directly towed is the traveling body, and the traveling body itself is moved in the traveling direction of the traveling body by the traction cable in the same manner as the above-described problem such as the inclination of the casing.
That is, it receives a traction force in a direction different from the direction of the pipeline. Therefore, pitching and yawing occur. However, the inertial sensor is housed in a casing behind it that is connected through a connecting body that can freely bend in the connecting direction, and the influence of the inclination of the traveling body is absorbed by this connecting body and the inertial sensor in the rear Not reachable. Therefore, pitching and yawing based on running direction fluctuations irrespective of the pipeline state do not occur, and the measurement accuracy is improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a vertical cross-sectional view showing a state in which an inertial sensor 12 is running in a pipeline 10 to be measured. Referring to FIG. 1, the inertial sensor 12 is covered by a casing 14, and wheels 16 are attached to the casing in front and rear. On the other hand, in front of the inertial sensor 12, a traveling body 18 having wheels 20 and capable of traveling in the pipeline 10 is provided. The rear end central position B of the traveling body 18 and the casing front end central position A of the inertial sensor 12 are connected by a rope 22 as a connecting body that can be bent in the connecting direction. One end of a cable 26 for towing is attached to a front end position of the traveling body 18. The rope 22 may be a rod or the like,
Is required to be rotatable. The freedom of bending in the connecting direction means this. The cable 26 is wound in the direction of the arrow A by a cable winding reel 24 installed outside the outlet 10B of the pipeline 10 to be run. Since it is necessary to move the inertial sensor 12 from the entrance 10A to the vicinity of the exit 10B of the pipeline 10 to be measured and measure the displacement from the reference position when the pipeline 10 is buried, the cable 26 is generally very long. Accordingly, while the inertial sensor 12 and the traveling body 18 are being pulled, the cable 26 hangs as shown. Therefore, as shown in the enlarged view of FIG.
Receives a force F1 in the direction of gravity (downward). Incidentally, the inertial sensor 12 is also connected to the traveling body 18.
Also, each of the wheels 1 is adjusted so as to substantially match the inner diameter of the pipeline so that the vehicle can travel smoothly when traveling in the pipeline 10.
6, 20 are attached. However, it is unavoidable to have a small gap, and therefore, when the traveling body 18 receives the force F1 from the cable 26 as described above, the traveling body 18 travels with a forward inclination as shown in FIG. This slope is exaggerated. In this case, the lift amount of the rear end center position B of the traveling body 18 due to the lifting of the rear wheel of the traveling body 18 is Δ
Assuming that h, the inclination angle θ1 of the rope 22 with respect to the central axis 10C of the conduit 10 is substantially expressed by the following equation. θ1 = Δh / L Here, L is the length of the rope 22. Originally, the lift amount Δh is at most about the gap between the inner periphery of the pipeline 10 and the wheels 20 of the traveling body 18 and is very small. Therefore, unless the length L of the rope 22 is extremely reduced, the inclination angle θ1 of the rope 22 is very small. Here, the inclination angle θ1 of the rope 22 is calculated on the assumption that the inertial sensor 12 does not rise, but if the inertia sensor 12 rises, the inclination angle θ1 becomes even smaller. Therefore, the inclination angle θ1 of the rope 22 is estimated to be large and is based on the above equation. However, as described above, the inclination angle θ1 still has a very small value, and the inclination angle θ0
(Eg, 10 degrees or more) is negligible. Therefore, the force for pulling the inertial sensor 12 in the upward or downward direction due to the very small inclination of the rope 22 hardly acts, and the traveling body 18 travels incline, but the inertial sensor 12 does not incline. , The pipeline 10 can be correctly measured. This is a characteristic advantage of the device of the present invention. Next, the advantages of the present invention will be described with reference to FIG. 3 for the case of a bent pipe 10 '. This pipe line 10 'is formed so as to extend from the straight pipe 10a to the other straight pipe 10c via a bent portion 10b. The traveling body 18 connected by a rope 22 in front of the inertial sensor 12 is pulled by a cable 26. In this case, if the vehicle 18 is not present, the inertial sensor 12 will still
Although the vehicle is traveling in a, it is attempted to be towed by the cable in the direction of the two-dot chain line 26 '. Accordingly, the vehicle travels in an inclined state by the gap between the wheel 16 and the straight pipe 10a by receiving the upward force F2 'in FIG. However, in the present invention, the traveling body 18 exists,
FIG. 3 shows a state immediately before the traveling body 18 has finished entering the front straight pipe 10c. Until this state, the inertial sensor 12 is still located at the rear straight pipe 10a, and the rope 22 is still almost inclined. Absent. Therefore, the inertial sensor 12 can travel so far without tilting. This is also because the traveling body 18 is traveling before the inertial sensor 12. Next, FIG. 4 shows a state in which the traveling body 18 travels in the straight pipe 10c, and the inertia sensor 12 finishes traveling of the straight pipe 10a and is about to enter the bent portion 10b. In this case, the straight pipe 10a and the straight pipe 1 are connected to the running direction of the inertial sensor 12 (the direction of the center axis of the straight pipe 10a).
0c, and a force F2 acts on the inertial sensor 12 in the upward direction in FIG. Therefore, the inertial sensor 12 can travel along the bent portion 10b. As described above, the inertial sensor 12 can correctly travel along the shape of the pipeline even if it is a curved pipeline due to the presence of the traveling body 18 ahead, and can accurately measure the displacement of the pipeline. Note that the present invention can be applied to the case where the bending direction of the bending line 10 'in FIGS. 3 and 4 is horizontal or vertical. Therefore, according to the present invention, the inertial sensor 12 can accurately measure the amount of displacement of the pipeline without causing pitching or yawing due to variations in the pipeline that do not originally exist. In the case of the bent pipe 10 ', the rope 2
The shorter the rope 22 is, the easier it is to see that if 2 is too long it will be like a two-dot chain line 26 'cable as shown in FIG. In the case of the straight pipe 10 described above, the longer the length L of the rope 22 is, the better the measurement accuracy is for the inertial sensor 12, so that the straight pipe 10a is connected to the straight pipe 10c by the bent portion 10b. In case, each straight pipe 1
It is better that the length of the rope L is longer when traveling on the roads 0a and 10c, but is shorter when traveling on the bend 10b. Therefore, in the case of an actual pipeline, the length of the rope 22 must be appropriately selected. As is apparent from the above description, according to the present invention, the traveling body located in front of the inertial sensor is directly connected to the cable, and the traveling body and the inertial sensor are connected in the connecting direction. The inertial sensor is not affected by a change in the pulling direction of the cable, and the displacement of the pipeline can be measured with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a state in which a pipeline is measured and traveled using a measuring device according to the present invention. FIG. 2 is an enlarged view of a main part of FIG. FIG. 3 is an explanatory view of another operation of the device according to the present invention. FIG. 4 is an explanatory diagram of an operation supplementing FIG. 3; [Description of Signs] 10, 10 'Measurement target pipes 10a, 10c Straight pipe 10b Bent portion 10C Pipe center axis 12 Inertial sensor 14 Casing 16 Wheel 18 Running body 22 Coupling body 26 Cable

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masaaki Kakura 2-5-1 Minamisuna, Koto-ku, Tokyo Inside Takenaka Corporation Technical Research Institute (72) Inventor Koji Matsuo 2-5-1 Minamisuna, Koto-ku, Tokyo No. Takenaka Corporation, Technical Research Institute (72) Inventor Takashi Kimura 8-21-1, Ginza, Chuo-ku, Tokyo Tokyo, Japan Inside (72) Inventor Hiroyuki Kikuchi 8-21 Ginza, Chuo-ku, Tokyo No. 1 Takenaka Corporation Tokyo Main Store (72) Inventor Junji Hori 8-21-1, Ginza, Chuo-ku, Tokyo Incorporated Takenaka Civil Engineering Company (72) Inventor Yoshiaki Hayakawa 345 Kamimachiya, Kamakura City, Kanagawa Prefecture Mitsubishi Inside Precision Co., Ltd. (72) Inventor Hiroshi Takagi 345 Kamimachiya, Kamakura City, Kanagawa Prefecture Inside Mitsubishi Precision Co., Ltd. (56) References JP JP-A-63-265107 (JP, A) JP-A-4-344414 (JP, A) JP-A-57-136101 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21 / 00 E21B 47/02 G01C 7/06 G01C 15/00

Claims (1)

(57) A displacement measuring device for measuring a displacement of a pipeline with respect to a reference position by an inertial sensor traveling on the pipeline, wherein a traveling direction of a casing of the inertial sensor is measured. A traveling body disposed in front of the traveling body and capable of traveling on the pipeline; and a traveling body disposed between the traveling body and a casing of the inertial sensor to connect the traveling body and the casing to each other. and a connecting body capable of bending of the connection direction while pulling the casing by traveling to, coupled to said traveling body includes a cable for pulling the running body, the travel direction rear side of the casing of the inertia sensor
Connect a long cable like the one above.
An apparatus for measuring the displacement of a pipeline using an inertial sensor.