JPH08136291A - Magnetic induction type underwater robot - Google Patents

Abstract

PURPOSE: To accurately position an inspecting underwater robot of the underwater outer plate of an ocean structure at the predetermined position of the plate. CONSTITUTION: A pair of magnetic sensors 5A, 5B are mounted at a robot body 3 having steering wheels 6A to 6D which can be steered while being brought into contact with the underwater outer plate 1 of an ocean structure. The wheels 6A to 6D are so controlled that the deviations of the sensors 5A, 5B from the magnetic paint film 2 coating the plate 1 becomes zero, and hence the body 3 can be traveled along the film. Thus, the plate 1 of a turret lathe 7 loaded with the outer plate inspecting unit on the body 3 can be accurately positioned at a predetermined position of the plate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater robot suitable for inspecting marine structures and the like, and more particularly to a magnetic guidance type underwater robot provided with highly accurate positioning means.

[0002]

2. Description of the Related Art An underwater inspection of an underwater structure such as an offshore structure has been conventionally performed by a diver. However, as the structure becomes larger and the operation deepens, it becomes difficult to inspect by a diver and an inspection by an underwater robot. The development of the method is progressing rapidly. In addition, the inspection content tends to become more sophisticated with the addition of measurement of the plate thickness and the condition of the coating film from the initial surface condition survey using an underwater television camera.

[0003]

By the way, in the case of the inspection method by the underwater robot, it is important to know the change of the plate thickness over time, for example, when measuring the plate thickness of the underwater outer plate. It is necessary to measure the determined position. This predetermined position range is usually not wide, for example in a circle with a diameter of 50 mm. In response to such a request, the conventional position detection of the underwater robot is provided, as shown in FIG. 4, with the ultrasonic oscillator 13 mounted on the underwater robot main body 3 and the seabed around the marine structure spaced apart from each other. This is performed by utilizing a plurality of ultrasonic receivers 14. In addition, the code | symbol 1 in FIG. 4 has shown the underwater outer skin of a marine structure.

However, such conventional techniques have the following drawbacks. (1) Since the confirmation of the inspection position on the underwater skin 1 of the marine structure is an indirect method in which an object other than the underwater part of the marine structure is used as a reference, accuracy is low. (2) The ultrasonic oscillator 13 and the ultrasonic receiver 14 are expensive and economical. (3) It is difficult to install the ultrasonic receiver 14 and the economical efficiency is low. In order to remedy some of the above drawbacks, a method of installing an ultrasonic wave receiver on the underwater outer plate 1 of the marine structure has been proposed, but in order to accurately detect the position of a vast outer plate area, There is a problem that a large number of ultrasonic receivers are required.

The present invention is intended to solve such drawbacks and problems. A magnetic induction zone is provided in advance on the underwater outer skin of a marine structure, and the underwater zone extends along the magnetic induction zone. By moving the robot, you can efficiently guide the underwater robot to the target position.
An object is to provide a magnetically guided underwater robot.

[0006]

In order to achieve the above object, a magnetically guided underwater robot according to claim 1 is an underwater robot for inspecting an underwater outer plate of a marine structure or the like.
A robot main body, a forward-backward thruster, a left-right moving thruster, and a vertical moving thruster attached to the robot main body, and a steering drive wheel attached to the robot main body and movable in contact with the underwater outer plate. With
A pair of magnetic sensors that can detect the amount of deviation from the magnetic induction band provided along the underwater outer plate are attached near the front and rear ends of the robot body, and the deviation detected by the same pair of magnetic sensors. It is characterized in that a controller for controlling the steering drive wheels is provided in order to eliminate the amount.

According to a second aspect of the magnetically guided underwater robot of the present invention, the underwater robot body is equipped with an inspection device for the underwater outer plate, and the magnetic induction band is applied to the underwater outer plate. It is characterized by being constituted by a magnetic coating film or a magnetic sheet attached to the above-mentioned underwater outer plate.

[0008]

In the magnetically guided underwater robot of the present invention described above,
A pair of magnetic sensors placed in front of and behind the underwater robot body detect the amount of deviation from the magnetic induction zone, and the front (rear) steering drive wheel is set so that the amount of deviation of the front (rear) magnetic sensor becomes zero. Control drive. This allows the underwater robot to move accurately along the magnetic induction zone.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetically guided underwater robot as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view thereof, and FIG. 2 is a table showing characteristic examples of its magnetic sensor.
FIG. 3 is a graph showing the results of the experimental example.

The magnetically guided underwater robot of this embodiment is
This is for inspecting the underwater outer panel 1 of the marine structure (hereinafter also abbreviated as "outer panel 1"). As shown in FIG. 1, the underwater robot body 3 has an underwater television camera for visual inspection. 11
And the lighting fixtures 10A and 10B are installed. The luminaires 10A and 10B are projected so as to surround the outer peripheral portion of the underwater robot body 3 and fixed to a guard pipe 4 for protecting the underwater robot body 3.

Further, in the underwater robot body 3, thrusters 12A, 12B for forward and backward movement which generate thrust in the forward and backward directions, and thrusters 8A, 8 for horizontal movement which generate thrust in the left and right directions.
B, vertical movement thrusters 9A and 9B that generate thrust in the vertical direction are mounted so as to be located inside the guard pipe 4, respectively. The vertical movement thrusters 9A and 9B move the underwater robot body 3 to the outer plate 1 of the marine structure when the underwater robot body 3 moves while contacting the outer plate 1 of the marine structure (details will be described later). It also acts to press.

Further, a pair of front and rear magnetic sensors 5A, 5
B is fixed to the guard pipe 4 and arranged at the front and rear ends on the center line in the lateral width direction on the upper surface of the underwater robot body 3. A pair of left and right steering drive wheels 6A, 6B and 6 capable of rolling contact with the outer plate 1 of the marine structure so as to be positioned near the front end and the rear end of the upper surface of the underwater robot body 3.
C and 6D are attached to the guard pipe 4. It should be noted that the steering drive wheels 6A to 6D are all arranged inside the guard pipe 4 and between the underwater robot body 3.

A magnetic coating film 2 is applied to the outer plate 1 of the marine structure. Reference numeral 7 in FIG. 1 indicates a rotary turret board equipped with an inspection device for the underwater outer plate 1. In addition,
The turret board 7 is attached to the upper surface of the underwater robot body 3. Further, reference numeral 15 indicates a multi-core cable for supplying electric power as a power source of each of the above-mentioned thrusters and inspection equipment and for taking out inspection result signals.

The movement to the magnetic coating film 2 applied to the outer plate 1 of the marine structure is performed by the horizontal movement of the underwater robot body 3 by the thrusters 12A and 12B for forward and backward movement and the thrusters 8A and 8B for horizontal movement. In addition, the underwater robot body 3
The diving is performed by the vertical movement thrusters 9A and 9B. When the underwater robot body 3 reaches the magnetic coating film 2, the underwater robot body 3 is pressed against the outer plate 1 of the marine structure by the vertical movement thrusters 9A and 9B. As a result, the drive wheels of the steering drive wheels 6A, 6B, 6C, 6D are brought into contact with and pressed against the outer plate 1 of the marine structure. Therefore, the underwater robot body 3 can be moved by the steering drive wheels 6A to 6D.

While the underwater robot body 3 is moving, the magnetic sensors 5A and 5B detect the magnetic coating film 2. The magnetic sensors 5A and 5B detect the amount of deviation of magnetism in the left-right direction as shown in FIG. Therefore, the magnetic sensor 5
A turret board 7 equipped with inspection equipment by detecting the amount of deviation of A (5B) (the amount of lateral displacement from the magnetic coating film 2) and controlling the driving wheels 6A, 6B (6C, 6D).
The underwater robot body 3 equipped with the above can be advanced along the magnetic coating film 2.

That is, the controller (not shown) controls the steering and speed of the front (rear) steering drive wheels so that the amount of deviation detected by the front (rear) magnetic sensor becomes zero. The underwater robot body 3 can be advanced along the magnetic coating film 2. The driving wheels 6A to 6D have a structure in which each of the driving wheels can independently rotate and change direction, as in the case of the 4WDS of an automobile. A small (area) inspection position arranged around the magnetic coating film 2 can be easily detected by magnetically guiding the underwater robot in this way. Similar results are obtained when a magnetic sheet attached to the underwater outer plate 1 is used instead of the magnetic coating film.

FIG. 3 shows the result of an experimental example in which the underwater robot of the above-mentioned embodiment is moved along the magnetic sheet. In FIG. 3, the first and second stages are the displacement amount of the magnetic sensor, the third to fourth stages are the steering angles of the steering drive wheels, the fifth stage is the wheel speed of the steering drive wheels, and the sixth stage is the vertical direction. It shows the operating amount of the thruster.

From the data shown in FIG. 3, it can be seen that when the magnetic sensor detects the amount of deviation, the angle of the steering wheel corresponding thereto changes, resulting in a smaller amount of deviation of the magnetic sensor. That is, the underwater robot can be moved along the magnetic sheet, and as a result, the underwater robot can detect a small inspection position arranged around the magnetic sheet. The data in FIG. 3 shows that it is effective as a robot for inspecting outer panels of objects.

[0019]

As described above in detail, according to the magnetically guided underwater robot of the present invention, the following effects and advantages can be obtained. (1) The underwater robot is controlled by controlling the driving wheels so that the amount of deviation between each magnetic sensor detected by the pair of magnetic sensors disposed in the underwater robot body and the magnetic induction zone is zero. Can be accurately moved along the magnetic induction zone. (2) According to the above (1), the inspection device mounted on the underwater robot body can be efficiently and accurately positioned at a predetermined position of the underwater outer plate.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic induction type underwater robot as an embodiment of the present invention.

FIG. 2 is a table showing a characteristic example of the magnetic sensor.

FIG. 3 is a graph showing the results of the same experimental example.

FIG. 4 is a conceptual diagram showing a conventional position detection technology for an underwater robot.

[Explanation of symbols]

 1 Underwater outer plate of marine structure 2 Magnetic coating film (or magnetic sheet) 3 Underwater robot body 4 Guard pipe 5A, 5B Magnetic sensor 6A, 6B, 6C, 6D Steering drive wheel 7 Turret board for mounting inspection equipment 8A, 8B Horizontal movement thruster 9A, 9B Vertical movement thruster 10A, 10B Underwater light 11 Underwater video camera 12A, 12B Forward movement thruster 13 Ultrasonic oscillator 14 Ultrasonic receiver

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B63B 35/44 A 8408-3D

Claims (2)

[Claims] 1. An underwater robot for inspecting an underwater skin of a marine structure or the like, and a robot body, a forward-backward thruster, a left-right moving thruster, and a vertical moving thruster attached to the robot main body, and the robot. A pair of magnetic sensors that are attached to the main body and have a steering drive wheel that is movable in contact with the underwater outer plate and that can detect the amount of deviation from a magnetic induction band provided along the underwater outer plate. Is attached to the front and rear ends of the robot body, and a controller for controlling the steering drive wheels is provided in order to eliminate the amount of deviation detected by the same pair of magnetic sensors. Underwater robot. 2. The magnetically guided underwater robot according to claim 1, wherein the underwater robot body is equipped with an inspection device for the underwater outer plate, and the magnetic induction band is applied to the underwater outer plate. A magnetic induction type underwater robot comprising a magnetic coating film or a magnetic sheet attached to the underwater outer plate.