JPH0886606A - Apparatus for recognizing underwater mark - Google Patents

Abstract

PURPOSE: To recognize the position of an inspection mark even if a marine creature adheres to and shields the inspection mark by detecting change of the distance to a structure to be inspected. CONSTITUTION: An eddy current-type displacement detection part 54 detects a change of the position of a magnetic body from the fact that the electromagnetic induction or eddy current changes in accordance with the position of the magnetic body in a magnetic field. Since an inspection mark 92 is formed out of a magnetic material and projects, it is detected that the detection part faces the mark 92 from change of the voltage or current of the detection part 54. A moving distance detection part 55 calculates the moving distance or position of an underwater inspection robot 11 by detecting and integrating the revolution number of a driving wheel 14. A data collection device 56 obtains and stores data output from the detection part 54 and data output from the detection part 55. An inspection mark-judging circuit 57 when receiving the data obtained by the device 56 operates and processes the data to calculate the presence and position of the mark 92.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is equipped with an underwater inspection robot for measuring and inspecting the plate thickness of an underwater outer plate of a ship, a marine structure, etc. The present invention relates to a device for recognizing an inspection mark that indicates a plate thickness measurement portion that is formed by being raised.

[0002]

2. Description of the Related Art FIG. 4 shows a situation in which a conventional underwater inspection robot measures the thickness of the bottom skin of a marine structure or the like underwater.
(A) is a side view, (B) is a bottom view, and (C) is a partially enlarged side view. A plate thickness measurement point is shown by forming an inspection mark 92 in an annular shape by swelling with a weld bead on the bottom outer plate of the structure 91 to be inspected such as a marine structure. The underwater inspection robot 11 that has entered the water moves by the drive wheels 14 along the bottom skin of the structure 91 to be inspected. The video camera 41 mounted on the underwater inspection robot 11 photographs the outer plate surface and displays it on the monitor television 42. When the underwater inspection robot 11 is moved by operating the control device 31 and the image of the inspection mark 92 is projected on the monitor TV 42, the plate thickness measuring device 2
1 is stopped so as to be at a position facing the center of the inspection mark 92, and the plate thickness of this portion is measured and sent to the control device 31 for recording. The above operation is performed for many measurement points,
Check the wear condition of the outer plate.

[0003]

The mark recognition means of the conventional underwater inspection robot is the video camera 41 as described above.
However, when it is necessary to inspect the plate thickness after several years, as shown in FIG. 4 (C), marine life 93 adheres to cover the inspection mark 92, and the video camera 41
Then, there is a problem that it becomes difficult or impossible to recognize the inspection mark 92, and the plate thickness inspection cannot be performed.

The present invention has been made in order to solve the above problems. Even if the marine life 93 adheres and covers the inspection mark 92, it is possible to recognize the position of the inspection mark 92, that is, the plate thickness measurement position. The object is to obtain an underwater mark recognition device capable of

[0005]

An underwater mark recognition apparatus according to the present invention includes an electromagnetic displacement detecting section for detecting a change in facing distance to a structure to be inspected and a moving distance detecting section for detecting a moving distance of an underwater inspection robot. Unit, a data acquisition device for acquiring and accumulating data from the moving distance detection unit and the electromagnetic displacement detection unit, and an inspection mark determination device for inputting the data from the data acquisition device and performing arithmetic processing to determine an inspection mark It is equipped with and.

[0006]

The electromagnetic displacement detector of the present invention detects that the inspection mark is faced because the electromagnetic induction increases and the current or voltage changes when the inspection mark made of a magnetic material and having a protruding shape is faced. Further, the moving distance detecting unit detects the moving distance, that is, the position of the underwater inspection robot. The data acquisition device acquires the data of the position of the underwater inspection robot output from the movement distance detection unit and the data of the change in current or voltage output from the electromagnetic displacement detection unit, that is, the data indicating whether or not the inspection mark is faced. accumulate. The inspection mark determination device inputs these data from the data acquisition device and performs arithmetic processing to determine the existence and position of the inspection mark.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1A and 1B show an embodiment of an underwater mark recognition apparatus according to the present invention. FIG. 1A is a side view of a state of use, FIG. 1B is a bottom view thereof, and FIG. FIG. 2 is a partially enlarged side view of the usage state. In FIGS. 1 (A), 1 (B) and 2, 91 is a structure to be inspected such as a marine structure,
Inspection marks 92 are attached to a large number of predetermined inspection points designated on the outer plate of the inspection target structure 91. The inspection mark 92 is formed by swelling in an annular shape with a weld bead centering on the inspection point. The inspection target structure 91 and the inspection mark 92 are made of steel and are magnetic materials. Note that reference numeral 93 indicates a marine organism that is likely to be attached and generated in the underwater portion of the structure 91 to be inspected.

In FIGS. 1A, 1B and 2, 1
Reference numeral 1 denotes an underwater inspection robot that measures and measures the plate thickness of the outer plate of the structure 91 to be inspected in water. The underwater inspection robot 11 is movable by the drive wheels 14 along the bottom skin of the structure 91 to be inspected. The underwater inspection robot 11 has
In addition to the plate thickness measuring device 21 and the video camera 41, the mark recognition device 51 according to the present invention is mounted. As the plate thickness measuring device 21, for example, an ultrasonic thickness gauge may be used.
The underwater inspection robot 11 is a control device 31 installed on land.
To a tether cable 33. The tether cable 33 has required tensile strength and bending flexibility, and is internally bundled with power wires, signal wires, and the like. A monitor television 42 is attached to the control device 31.

As shown in FIG. 1C, the mark recognizing device 51 includes an eddy current type displacement detecting section (electromagnetic displacement detecting section) 54, a moving distance detecting section 55, and a computing section 53 which constitute a detecting section 52. It is composed of a data acquisition device 56 and an inspection mark discrimination circuit 57 which constitute the device. The eddy current displacement detection unit 54 detects a change in the position of the magnetic body by changing the electromagnetic induction or the eddy current depending on the position of the magnetic body in the magnetic field generated by energizing the coil. Since the inspection mark 92 is made of a magnetic material and protrudes, it is possible to detect that the inspection mark 92 is faced by a change in voltage or current of the eddy current displacement detection unit 54. Moving distance detector 5
5 is for calculating the moving distance or the position of the underwater inspection robot 11 by detecting and integrating the number of rotations of the drive wheels 14. The data acquisition device 56 acquires and stores the data output from the eddy current displacement detection unit 54 and the data output from the movement distance detection unit 55. The inspection mark determination circuit 57 inputs the data acquired and accumulated by the data acquisition device 56, performs arithmetic processing, and determines the inspection mark 92.
The existence of and the position of the.

In FIG. 1, the mark recognition device 5
1 is shown to be equipped with the underwater inspection robot 11,
Of course, the sensor part of the mark recognition device 51 has to be provided at a predetermined portion of the underwater inspection robot 11, but the parts other than the sensor part are connected by signal wires of the tether cable and installed on land. It can be provided in the control device 31.

Next, the operation of the embodiment shown in FIG. 1 will be described. The underwater inspection robot 11 is placed in water with the drive wheel 14 facing upward, and the drive wheel 14 is brought into contact with the bottom skin of the structure 91 to be inspected by using the buoyancy of the underwater inspection robot 11, for example. While instructing from the control device 31, the driving wheels 14 are rotationally driven to move the underwater inspection robot 11 along the bottom skin of the inspection target structure 91, the bottom skin of the inspection target structure 91 is moved by the video camera 41. The photograph is taken and observed on the monitor TV 42. When the inspection mark 92 is visually recognized on the monitor television 42, the control device 31 operates while observing the inspection mark 92 to move the underwater inspection robot 11 so that the plate thickness measuring device 21 faces the central portion of the inspection mark 92. Alternatively, since the relational position between the video camera 41 and the plate thickness measuring device 21 is determined, the video camera 41 displays the inspection mark 9
The underwater inspection robot 11 may be moved by a predetermined distance from the position directly facing 2. Then, the plate thickness measuring device 21 measures the plate thickness. The above operation is repeated for each inspection mark 92.

However, after several years have passed, when a thickness inspection is to be carried out, as shown in FIGS. 1 (A) and 2, marine life 93 adheres to the bottom skin of the structure 91 to be inspected. Since the inspection mark 92 is covered, the detection of the inspection mark 92 by the video camera 41 becomes difficult or impossible. At that time, the eddy current displacement detection unit 54 of the mark recognition device 51
By generating a magnetic field, marine organisms that are not magnetic materials 93
Irrespective of the presence or absence of thickness, thickness, etc., the inspection mark 92 that is a magnetic substance and has a shape protruding from the surface of the inspection target structure 91
It can be known by detecting the change in the current or voltage flowing through the coil of the eddy current displacement detection unit 54.

In FIG. 1 and FIG. 2, while detecting the data of the current or voltage flowing through the coil of the eddy current type displacement detecting section 54 corresponding to the facing distance to the magnetic body, the moving distance detecting section 55 detects the underwater inspection robot 11. Of the inspection mark discriminating circuit 57 by detecting the moving distance or position of the data and sending each data to the inspection mark discriminating circuit 57 through the data acquisition device 56.
As shown in FIG. 3, reference numeral 7 continuously indicates the points at each time point every predetermined second with the moving distance or position as the abscissa and the facing distance as the ordinate. If the lower convex portion P1 shown in the figure appears, it is estimated that it has exceeded one annular portion of the inspection mark 92, and if the lower convex portion P2 appears within a distance within the diameter of the inspection mark 92, another portion of the inspection mark 92 will appear. It is estimated to have exceeded. If necessary, the position of the inspection mark 92 can be confirmed by changing the traveling path of the underwater inspection robot 11 and moving the underwater inspection robot 11 to create a diagram as shown in FIG. If the position of the inspection mark 92 can be confirmed, the inspection mark 9
The underwater inspection robot 11 is moved so as to pass through the center of 2, and from the position of P0 which is the center of P1 and P2 in FIG.
The plate thickness measuring device 21 is moved toward the plate thickness measuring device 21 in the direction and distance from the eddy current displacement detector 54, and the plate thickness measuring device 21 is faced to the center of the inspection mark 92 to measure the plate thickness. By repeating the above operation and measuring the plate thickness of the central portion of each inspection mark 92, it is possible to know the condition of the plate thickness of the outer plate of the inspection target structure 91 in water.

In FIG. 1, the plate thickness measuring device 21 and the mark recognizing device 51 are shown to be provided at the head of the underwater inspection robot 11, but the surface of the marine organism 93 attached to the structure 91 to be inspected is Since there is unevenness, it is desirable to provide it in the central portion of the underwater inspection robot 11 so that the face-to-face distance between the plate thickness measuring device 21 and the mark recognition device 51 changes with the movement of the underwater inspection robot 11 as little as possible.

[0015]

As described above, according to the present invention, the electromagnetic displacement detecting section, the moving distance detecting section, and the data acquisition even if the inspection mark is covered by the marine organisms attached to the structure to be inspected underwater. With the device and the inspection mark discriminating circuit, it is possible to detect the existence of the inspection mark and the position thereof by performing data detection, collection and arithmetic processing to measure the plate thickness. This allows
The thickness of offshore structures can be inspected without any problems.

[Brief description of drawings]

FIG. 1 shows an underwater mark recognition apparatus according to an embodiment of the present invention, (A) is a side view showing a usage state, (B) is a bottom view thereof, and (C) is a block diagram.

FIG. 2 is a partially enlarged side view showing a usage state of the underwater mark recognition apparatus according to the embodiment of the present invention.

FIG. 3 is a mark discrimination diagram of the underwater mark recognition device according to the embodiment of the present invention.

FIG. 4 (A) is a side view of a conventional underwater inspection robot,
(B) is a bottom view and (C) is a partially enlarged side view.

[Explanation of symbols]

11: Underwater inspection robot, 14: Drive wheel, 21: Plate thickness measuring device, 31: Control device, 33: Tether cable,
41: video camera, 42: monitor TV, 51: mark recognition device, 54: eddy current displacement detection unit, 55: moving distance detection unit, 56: data acquisition device, 57: inspection mark discrimination circuit, 91: inspection target structure Object, 92: inspection mark, 93: marine organism.

Claims (1)

[Claims] 1. A device equipped on an underwater inspection robot for recognizing a protruding inspection mark made of a magnetic material attached to a structure to be inspected, and detecting a change in facing distance to the structure to be inspected. An electromagnetic displacement detecting unit, and a moving distance detecting unit that detects a moving distance of the underwater inspection robot,
A data acquisition device that acquires and stores data from the moving distance detection unit and the electromagnetic displacement detection unit, and an inspection mark determination device that inputs the data from the data acquisition device and performs arithmetic processing to determine an inspection mark. An underwater mark recognition device characterized in that