JP3567583B2 - Underwater mobile robot positioning method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an underwater mobile robot that inspects a moving reactor along a vertical inner wall surface in a reactor pressure vessel filled with cooling water, and particularly to a method of positioning the underwater mobile robot with respect to the pressure vessel. is there.
[0002]
[Prior art]
Due to the nature of nuclear facilities such as nuclear power plants, high safety is required. Therefore, periodic inspections such as ISI (in-service inspection) are required, and ultrasonic inspection is one of the important inspections. There is a non-destructive inspection of the reactor pressure vessel using the method.
[0003]
As is well known, this nondestructive inspection by ultrasonic flaw detection is to send an ultrasonic wave, which is an elastic wave, into an object, and to non-destructively measure a flaw or a defect inside the object according to a state of reflection. In the method, a rail is provided outside the reactor pressure vessel, and along this rail, a method of inspecting the pressure vessel while running a mobile inspection robot equipped with an ultrasonic flaw detector and the like, and on the outer surface of the pressure vessel, There is a method in which the mobile inspection robot is directly sucked and inspected while traveling along the surface of the robot without track.
[0004]
In the case of such an inspection method using a trackless mobile inspection robot, workers often do not directly enter the vicinity of the reactor pressure vessel, and installation and control of this mobile inspection robot are performed by remote control. Because of this, the positioning of the mobile inspection robot with respect to the reactor pressure vessel becomes important. Conventionally, as a positioning method of the mobile inspection robot, an ultrasonic wave or a laser distance meter is provided at an arbitrary reference point set on the surface of the pressure vessel, and a planimeter or the like for detecting a traveling distance is provided on the robot body side. There is a method of detecting the position of the mobile inspection robot with respect to a reference point whose position is known in advance.
[0005]
[Problems to be solved by the invention]
Incidentally, the inspection by the conventional trackless mobile inspection robot as described above has been performed from the outside of the reactor pressure vessel, but in order to perform a more reliable inspection, the above-described inspection is performed on the inner surface of the reactor pressure vessel. It is being studied to install such a trackless mobile inspection robot and perform the inspection from inside.
[0006]
However, since the inside of this reactor pressure vessel is filled with reactor water, laser or ultrasonic waves that measure the direct distance as described above cause a great deal of attenuation in water and cause irregular reflection. However, it has been difficult to accurately position the mobile inspection robot in the water.
[0007]
Therefore, the present invention has been devised in order to effectively solve such a problem, and an object of the present invention is to enable easy and accurate positioning of a mobile inspection robot in reactor water of a reactor pressure vessel. An object of the present invention is to provide a novel underwater mobile robot positioning method.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides a method of positioning an underwater mobile robot that moves on an orbit along a vertical wall of a pressure vessel filled with reactor water while adsorbing on the vertical wall. If, Rutotomoni provided water depth meter for measuring the water depth, respectively and the robot body, a light beam emitter and a light reflection amount sensor provided in the robot body, detected by the depth gauge by running the water mobile robot in the vertical direction After measuring the vertical position of the robot body with respect to the pressure vessel from the difference in water depth, the underwater mobile robot is turned 90 ° along the vertical wall, and then the underwater mobile robot is turned on the vertical wall. The light beam is emitted from the light beam projector while being moved in the horizontal direction, and the light beam reflected from the furnace internal structure whose position is known in advance is reflected. The horizontal position of the robot body is detected by detecting the amount with the light reflection amount sensor, and the position of the underwater mobile robot with respect to the pressure vessel determined from the vertical position and the horizontal position is determined as the travel origin. While detecting the horizontal position while measuring the horizontal movement amount of the underwater mobile robot based on this origin, the position of the underwater mobile robot is detected by detecting the vertical position with the depth gauge It was made .
[0009]
Therefore, even in the pressure vessel filled with reactor water, the position of the underwater mobile robot with respect to the pressure vessel can be accurately detected, so that a highly reliable inspection of the pressure vessel can be performed.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.
[0011]
FIG. 1 shows an embodiment of a method for positioning a submersible mobile robot according to the present invention. In FIG. 1, 1 is a reactor pressure vessel having a substantially cylindrical shape, and 2 is filled in the pressure vessel 1. Reactor water 3 is a submersible robot that travels while adsorbing to the vertical wall surface of the pressure vessel 1, and 4 is a furnace internal structure housed in the pressure vessel 1, and particularly, the furnace internal structure 4 is a core Is composed of a shroud 4a and a plurality of cylindrical jet pumps 4b standing upright around the shroud 4a.
[0012]
The underwater mobile robot 3 is an application of the one proposed by the present applicant (Japanese Patent Application No. 6-319772), and has a configuration as shown in FIGS. FIG. 4 is a partially broken plan view showing an embodiment of the underwater mobile robot, and FIG. 5 is a side sectional view thereof. As shown in the figure, the underwater mobile robot 3 is mounted on a robot main body 5 having a substantially rectangular frame 5b fixed in a substantially disc-shaped cylindrical body 5a with an open bottom, and a vertical wall surface of the pressure vessel 1. A is mainly provided with a suction means 6 for suctioning the robot body A and a traveling means 7 for moving the robot body 5 along the vertical wall surface A.
[0013]
That is, the suction means 6 drives a pair of drainage ports 6a, 6a formed in the cylindrical body 5a, the thrust fans 6b, 6b located in the drainage ports 6a, 6a, respectively, and the thrust fans 6b, 6b. As shown in FIG. 5, the thrust fans 6b, 6b forcibly drain the water in the robot body 5 from the drain ports 6a, 6a. By setting the internal pressure of the pressure vessel 5 to a pressure lower than the surrounding water pressure, the robot body 5 is attracted to the vertical wall A of the pressure vessel 1 as shown in FIG. On the other hand, the traveling means 7 comprises a pair of traveling wheels 7a, 7a attached to the frame 5b side of the robot body 5, and traveling motors 7b, 7b for driving the traveling wheels 7a, 7a respectively. By driving the wheels 7a, 7a to rotate in the forward and reverse directions or in the same direction, the vehicle travels while turning on the wall surface A at right angles, and can be moved to an arbitrary position on the vertical wall surface A. In the vicinity of the traveling means 7, there are provided planimeters 8, 8 comprising a friction roller, a rotary encoder, etc., so that the traveling distance of the robot body 5 on the vertical wall A can be detected. Note that the fan motors 6c, 6c, the power supply lines on the side of the traveling motors 7b, 7b, the control lines, the signal lines of the planimeters 8, 8 and the like are combined in a cable 9 connected to the robot body 5 and are shown in FIG. 10 side.
[0014]
As shown in FIGS. 4 and 5, a light beam projector 11 for irradiating a light beam B and a light for detecting an amount of reflection of the light beam B are provided on a flat portion of a cylindrical body 5 a constituting the robot body 5. A reflection amount sensor 12 is provided. The light beam projector 11 emits a light beam B in a horizontal direction, that is, in the direction of the furnace internal structure 4, and the light reflection amount sensor 12 detects the reflection amount of the light beam B. Then, the distance between the robot body 5 and the in-furnace structure 4 is measured. Further, a water depth gauge 13 composed of an integrated semiconductor pressure sensor, a piezoelectric pressure sensor, or the like is provided on a flat portion of the cylindrical body 5a, and detects a water pressure in the pressure vessel 1 in which the robot body 5 is located. It has become. The power supply line, the signal line, and the like of the light beam projector 11, the light reflection amount sensor 12, and the water depth gauge 13 are also collected in the cable 9 in the same manner as described above, and the light beam projector 11, the light reflection amount sensor 12 are transmitted to the control unit 10. A water depth gauge 13 is connected to the attached horizontal position detection unit 17 and a water depth measurement unit 16, respectively. In FIGS. 4 and 5, reference numeral 15 denotes a floating body filled with air. The floating body 15 is provided with an appropriate buoyancy to offset the weight of the robot main body 5 and facilitate the movement of the robot main body 5. It has become. In the figure, reference numeral 14 denotes a ball caster that rolls in contact with the vertical wall surface A, and supports the robot body 5 at three points on the vertical wall surface A together with the running wheels 7a. Although not shown, the robot main body 5 is provided with a gravity sensor for detecting its posture and inspection means such as the above-mentioned non-destructive flaw detector for detecting the vertical wall A. It is.
[0015]
Next, an embodiment of the underwater mobile robot positioning method according to the present invention using such a configuration will be described.
[0016]
First, as shown in FIG. 1, an arbitrary reference point P is set in the vicinity of the water surface in the reactor water of the pressure vessel 1, and a reference depth gauge 18 for measuring the water depth is installed at the reference point P, as described above. After the underwater moving robot 3 is put into the reactor water 2 from above the pressure vessel 1 by a manipulator (not shown) or the like, the water is adsorbed on the vertical wall A of the pressure vessel 1 and travels vertically downward along the same. The underwater mobile robot 3 is stopped at any approximate position on the vertical wall A by visual observation, an ITV camera, or the like.
[0017]
Next, the water pressure is detected by the water depth gauge 18 provided at the reference point P, the water pressure at the position is detected by the water depth gauge 13 of the underwater mobile robot 3, and the output value is attached to the control unit 10. Is input to the measured water depth measurement unit 16. The water depth measurement unit 16 calculates the difference between the water pressures detected by the two water depth gauges 13 and 18, calculates the distance between the arbitrary reference point P of the pressure vessel 1 and the underwater mobile robot 3, and calculates the value. Input to the control unit 10. The control unit 10 determines the pressure based on the distance between the arbitrary reference point P calculated by the water depth measurement unit 16 and the underwater mobile robot 3 and data such as the shape and size of the pressure vessel 1 which is known in advance. The position of the underwater mobile robot 3 with respect to the container 1 in the vertical direction can be specified. That is, in the present invention, not only the single depth gauge 13 provided on the underwater mobile robot 3 but also the depth gauge 18 is provided on the reference point P side, and the difference between the depth gauges 13 and 18 is detected. Accurate water depth measurement is possible even if the water pressure fluctuates greatly due to fluctuations or shaking of the reactor water. In addition, as a result of comparing the measured water depth obtained by such a method with the actual water depth, the error of the water depth was only 0.02%, and it was found that the water depth could be measured with extremely high accuracy.
[0018]
Next, when the position of the underwater mobile robot 3 in the vertical direction with respect to the pressure vessel 1 was specified in this way, the underwater mobile robot 3 was turned 90 ° along the vertical wall A as shown in FIG. After that, while irradiating the light beam B from the light beam projector 11 toward the furnace internals 4, the light beam B is slowly moved along the horizontal direction of the vertical wall A of the pressure vessel 1 to change the amount of reflection of the light beam B. Is also detected by the light reflection amount sensor 12. In general, as the furnace internal structure 4 of the pressure vessel 1, a cylindrical jet pump 4b as shown in the figure is installed at a position closest to the vertical wall surface A. 4b is a target structure to be measured by the light beam B. Then, since the reflection amount of the light beam B changes in proportion to the distance from the surface of the jet pump 4b, the horizontal position detection unit 17 to which the output value is input measures the reflection amount and controls the control unit. Enter 10 The control unit 10 graphically displays the relationship between the output value from the horizontal position detection unit 17 and the travel distance of the underwater mobile robot 3 detected by a planimeter or the like as shown in FIG. Is calculated. Further, the control unit 10 calculates the offset distance between the center position of the cylinder and the current position of the underwater mobile robot 3, and based on the installation dimensions of the jet pump 4b known in advance, etc. , The horizontal position of the underwater mobile robot 3 can be specified.
[0019]
When the position of the underwater mobile robot 3 with respect to the pressure vessel 1 is specified from the position of the underwater mobile robot 3 in the vertical direction and the position in the horizontal direction of the pressure vessel 1 thus determined, this position is determined. 3 is determined as the traveling origin, and thereafter the movement of the underwater mobile robot 3 is measured based on this origin. In the vertical direction, the measurement is continued by the depth gauges 13 and 18, and thereafter, by the gravity sensor and the planimeter. By obtaining the trajectory, the position of the underwater mobile robot 3 with respect to the pressure vessel 1 can be accurately detected.
[0020]
【The invention's effect】
In short, according to the present invention, a plurality of depth gauges are used for vertical positioning, and the amount of reflection of a light beam applied to a furnace internal structure is used for horizontal positioning. The underwater mobile robot can be accurately positioned with respect to.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an embodiment of the present invention.
FIG. 2 is a view taken in the direction of arrows AA in FIG.
FIG. 3 is a graph showing a relationship between a light reflection amount sensor and a traveling distance of an underwater mobile robot.
FIG. 4 is a partially broken plan view showing an embodiment of an underwater mobile robot used in the method of the present invention.
FIG. 5 is a side sectional view showing one embodiment of an underwater mobile robot used in the method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 2 Reactor water 3 Underwater moving robot 4 Reactor internal structure 5 Robot main body 11 Light beam projector 12 Light reflection amount sensor 13, 18 Water depth gauge A Vertical wall surface B Light beam P Reference point

Claims (1)

In a positioning method of an underwater mobile robot that moves along an orbit along a vertical wall of a pressure vessel filled with reactor water while moving along the track, an arbitrary reference point in the reactor water and a depth of the water are respectively set to the robot body. Rutotomoni provided water depth meter for measuring the light beam emitter and a light reflection amount sensor provided in the robot body, by running the water mobile robot in the vertical direction above with respect to the pressure vessel from the difference in depth which is detected by the depth gauge After measuring the position of the robot body in the vertical direction, the underwater mobile robot is turned 90 ° along the vertical wall surface, and then the light beam is moved while moving the underwater mobile robot along the horizontal direction of the vertical wall surface. A light beam is emitted from the light projector, and the amount of reflection of the light beam reflected from the furnace internal structure whose position is known in advance is detected by the light reflection amount sensor. And the horizontal position of the robot body is detected, and the position of the underwater mobile robot with respect to the pressure vessel determined from the vertical position and the horizontal position is used as the traveling origin, and the underwater mobile robot is based on this origin. An underwater mobile robot, wherein the position of the underwater mobile robot is detected by detecting a vertical position with the depth gauge while measuring a horizontal position while measuring a horizontal movement amount of the underwater mobile robot. Positioning method.

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