JPH09211178A - Method for positioning an underwater traveling robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately position a traveling inspection robot in the reactor water in a reactor pressure vessel. SOLUTION: In a method for positioning an underwater traveling robot 3 which tracklessly travels along a vertical wall face A of a reactor pressure vessel 1 filled with the reactor water 2, while sticking to it, bathometers 13 and 18 are respectively provided at a given datum point P in the reactor water 2, and on the main body of the robot to measure the water depth of each point. The vertical position of the main body of the robot is measured to the pressure vessel 1 by the difference in the water depth detected by the bathometers 13 and 18. At the same time, the main body of the robot is equipped with a light beam projector and a light reflection amount sensor. The light beam projector irradiates light beams B in the direction of in-vessel structures 4 whose positions have already been identified, and the horizontal position of the main body of the robot is detected by the amount of reflection. The position of the underwater traveling robot 3 to the pressure vessel 1 is determined by these vertical and horizontal positions of it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater mobile robot for inspecting a reactor pressure vessel filled with cooling water while moving along a vertical inner wall surface, and more particularly to an underwater movement for the pressure vessel. The present invention relates to a robot positioning method.

[0002]

2. Description of the Related Art Since nuclear facilities such as nuclear power plants are required to have high safety by nature, periodic inspections such as ISI (in-service inspection) are obligatory. As one of them, there is a nondestructive inspection of a reactor pressure vessel using an ultrasonic flaw detection method.

As is well known, this non-destructive inspection by ultrasonic flaw detection is intended to send an ultrasonic wave as an elastic wave into the inside of an object and measure the scratches or defects inside the object non-destructively by the reflection state. Specifically, a rail is provided on the outside of the reactor pressure vessel, and a method for inspecting the pressure vessel while running a mobile inspection robot equipped with an ultrasonic flaw detector along the rail, and a method for inspecting the pressure vessel There is a method in which the mobile inspection robot is directly attracted to the surface and is inspected while running along the surface in a trackless manner.

In the case of such an inspection method using a non-orbital mobile inspection robot, an operator often does not directly enter the vicinity of the reactor pressure vessel, and the installation and control of this mobile inspection robot is not possible. Positioning of the mobile inspection robot with respect to the reactor pressure vessel is important because it is performed by remote control. As a method of positioning the movement inspection robot, conventionally, an ultrasonic wave or a laser range finder is provided at an arbitrary reference point set on the surface of the pressure vessel, and a planimeter etc. for detecting a travel distance is provided on the robot body side. , A method of detecting the position of the mobile inspection robot with respect to a reference point whose position is known in advance.

[0005]

Inspection by the conventional trackless mobile inspection robot as described above,
Although it was performed from the outside of the reactor pressure vessel, in order to perform a more reliable inspection, the trackless mobile inspection robot as described above was installed on the inner surface of the reactor pressure vessel, and the inspection was performed from the inside. Considered to do.

However, since the reactor water is filled in the reactor pressure vessel, the laser and ultrasonic waves for measuring the direct distance as described above have large attenuation in water and diffuse reflection. Therefore, it is difficult to accurately position the mobile inspection robot in water.

Therefore, the present invention has been devised in order to effectively solve such a problem, and the purpose thereof is to easily and accurately position the mobile inspection robot in the reactor water of the reactor pressure vessel. (EN) A novel underwater mobile robot positioning method capable of performing the above.

[0008]

In order to solve the above-mentioned problems, the present invention provides a positioning method for an underwater mobile robot which adsorbs on a vertical wall of a pressure vessel filled with reactor water and moves tracklessly along the same. , A reference point in the reactor water and a depth gauge for measuring the depth of the robot body, respectively, the vertical position of the robot body relative to the pressure vessel from the difference in water depth detected by these depth gauges In addition to measuring, the robot body is equipped with a light beam projector and a light reflection amount sensor, and from this light beam projector, a light beam is emitted in the direction of the internal structure whose position is known in advance, and from that reflection amount the The horizontal position of the robot body is detected, and the position of the underwater mobile robot with respect to the pressure vessel is determined from these vertical position and horizontal position. It is intended.

Therefore, since the position of the underwater mobile robot with respect to the pressure vessel can be accurately detected even in the pressure vessel filled with the reactor water, highly reliable inspection of the pressure vessel can be performed. Become.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a positioning method for an underwater mobile robot according to the present invention.
Is a reactor pressure vessel having a substantially cylindrical shape, 2 is reactor water filled in the pressure vessel 1, 3 is an underwater mobile robot which runs while adsorbing on a vertical wall surface of the pressure vessel 1, 4 is the pressure vessel 1 It is an internal structure housed inside, and in particular, the internal structure 4 comprises a core of a shroud 4a, and a plurality of cylindrical jet pumps 4b ... Standing around the shroud 4a.

The underwater mobile robot 3 is an application of the one previously proposed by the present applicant (Japanese Patent Application No. 6-319972), and has a structure as shown in FIGS. 4 and 5. 4 is a partially cutaway 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 includes a robot main body 5 in which a substantially rectangular frame 5b is fixed in a substantially disk-shaped cylindrical body 5a having an opening at the bottom, and this is mounted on a vertical wall surface of the pressure vessel 1. It is mainly provided with a suction means 6 for adsorbing to A and a traveling means 7 for traveling the robot main body 5 along the vertical wall surface A.

That is, the suction means 6 has a pair of drainage ports 6a, 6a formed in the cylindrical body 5a, and the drainage ports 6a, 6a, 6a.
Thrust fans 6b, 6b respectively located in 6a
And the fan motors 6c, 6c for driving the thrust fans 6b, 6b. As shown in FIG. 5, the thrust fans 6b, 6b are used to discharge the water in the robot body 5 from the drain port 6a. , 6a is forcibly drained to make the internal pressure of the robot body 5 negative than the surrounding water pressure, so that the robot body 5 is attracted to the vertical wall surface A of the pressure vessel 1 as shown in FIG. It is like this. On the other hand, the traveling means 7 includes a pair of traveling wheels 7a, 7a attached to the frame 5b side of the robot body 5,
These traveling wheels 7a, 7a are composed of traveling motors 7b, 7b for rotationally driving the traveling wheels 7a, 7a, respectively.
By rotating and driving a and 7a in the forward and reverse directions or in the same direction, it is possible to travel while turning on the wall surface A at right angles and move to any position on the vertical wall surface A. Further, in the vicinity of the traveling means 7, there are provided planimeters 8 including a friction roller and a rotary encoder, so that the traveling distance of the robot body 5 on the vertical wall surface A can be detected.
The fan motors 6c, 6c, the traveling motor 7b,
The power supply line on the 7b side, the control line, the signal lines of the planimeters 8 and 8 and the like are put together in a cable 9 connected to the robot body 5 and connected to the control unit 10 side shown in FIG.

Further, as shown in FIGS. 4 and 5, the light beam B is formed on the plane portion of the cylindrical body 5a constituting the robot body 5.
A light beam projector 11 for irradiating the light beam and a light reflection amount sensor 12 for detecting the reflection amount of the light beam B are provided,
The light beam projector 11 irradiates the light beam B in a horizontal direction, that is, in the direction of the in-core structure 4, and the light reflection amount sensor 12 detects the reflection amount of the light beam B to detect the robot body 5 and the in-core structure. The distance to the object 4 is measured. Further, a water depth gauge 13 including an integrated semiconductor pressure sensor, a piezoelectric pressure sensor, etc. is provided on the flat surface of the cylindrical body 5a to detect the water pressure in the pressure vessel 1 in which the robot body 5 is located. It is like this. Then, the light beam projector 11, the light reflection amount sensor 12,
The power line, the signal line, etc. of the water depth meter 13 are also bundled in the cable 9 in the same manner as above, and the light beam projector 11 and the light reflection amount sensor 1
2 is on the side of the horizontal position detector 17 attached to the controller 10,
The water depth gauge 13 is connected to the water depth measurement unit 16 side. It should be noted that reference numeral 15 in FIGS. 4 and 5 denotes a floating body that is filled with air. By giving an appropriate buoyancy to the robot body 5, the weight of the robot body 5 is offset and the movement of the robot body 5 is facilitated. It has become. In addition, reference numeral 14 in the drawing denotes a ball caster that rolls in contact with the vertical wall surface A,
The robot main body 5 is supported at three points on the vertical wall surface A together with the traveling wheels 7a, 7a described above. Although not shown, the robot body 5 is of course provided with a gravity sensor for detecting its posture and an inspection means such as the nondestructive flaw detection device as described above for flaw detection on the vertical wall surface A. Is.

Next, an embodiment of the positioning method for the underwater mobile robot, which is the method of the present invention, will be described using such a configuration.

First, as shown in FIG. 1, an arbitrary reference point P is set near the water surface in the reactor water of the pressure vessel 1, and a reference water depth gauge 18 for measuring the water depth is installed at the reference point P. After the above-mentioned underwater mobile robot 3 is put into the reactor water 2 from above the pressure vessel 1 by a manipulator or the like (not shown), it is adsorbed on the vertical wall surface A of the pressure vessel 1 and runs vertically downward along this. While doing so, the underwater mobile robot 3 is stopped at an arbitrary approximate position on the vertical wall surface A by visual inspection or an ITV camera.

Next, the water depth gauge 1 provided at this reference point P
The water pressure is detected at 8, 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 input to the water depth measurement unit 16 attached to the control unit 10. In the water depth measuring unit 16, these two water depth gauges 13,
The water pressure difference detected at 18 is calculated, the distance between any underwater mobile robot 3 from an arbitrary reference point P of the pressure vessel 1 is calculated, and the value is input to the control unit 10. In the control unit 10,
Underwater movement with respect to the pressure vessel 1 based on the distance between the arbitrary underwater mobile robot 3 calculated from the water depth measuring unit 16 and the data such as the shape and size of the pressure vessel 1 which are known in advance. The vertical position of the robot 3 can be specified. That is, in the present invention, not only the single water depth gauge 13 provided on the underwater mobile robot 3 but also the water depth gauge 18 is provided on the reference point P side to detect the difference between these water depth gauges 13, 18. Even if the water pressure fluctuates greatly due to fluctuations and shaking of reactor water, accurate water depth measurement becomes possible. As a result of comparing the measured water depth obtained by such a method and the actual water depth, the error of the water depth is only 0.
It was 02%, and it was found that the water depth could be measured with extremely high accuracy.

Next, in this way, the underwater mobile robot 3
When the vertical position of the underwater mobile robot 3 is specified with respect to the pressure vessel 1, the underwater mobile robot 3 is turned by 90 ° along the vertical wall surface A, and then the light beam projector 1 is turned on, as shown in FIG.
While irradiating the light beam B from 1 to the internal structure 4 direction,
The pressure vessel 1 is slowly moved along the horizontal direction of the vertical wall surface A and the change in the reflection amount of the light beam B is also detected by the light reflection amount sensor 12. Generally, as the reactor 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 thereof. 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 in 10. In the control unit 10, the relationship between the output value from the horizontal position detection unit 17 and the traveling distance of the underwater mobile robot 3 detected by the planimeter etc. is made into a graphic as shown in FIG.
Calculate the center position of the cylinder. 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 previously known installation dimension drawing of the jet pump 4b,
The horizontal position of the underwater mobile robot 3 with respect to the pressure vessel 1 can be specified.

If 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 with respect to the vertical direction of the pressure vessel 1 and the position with respect to the horizontal direction thus obtained, this position is determined. The underwater mobile robot 3 is positioned as the traveling origin, and then the movement of the underwater mobile robot 3 is measured based on this origin, but the vertical direction continues to be measured by the depth gauges 13 and 18, while the gravity sensor is used thereafter. And the trajectory with the planimeter, the underwater mobile robot 3 for the pressure vessel 1
The position of can be detected accurately.

[0020]

In summary, according to the present invention, a plurality of water depth gauges are used for vertical positioning, and the amount of reflection of the light beam applied to the reactor internal structure is used for horizontal positioning. Therefore, the underwater mobile robot can be accurately positioned with respect to the pressure vessel.

[Brief description of 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 cutaway 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 an embodiment of an underwater mobile robot used in the method of the present invention.

[Explanation of symbols]

 1 Reactor pressure vessel 2 Reactor water 3 Underwater mobile robot 4 Reactor internal structure 5 Robot body 11 Light beam projector 12 Light reflection sensor 13,18 Depth gauge A Vertical wall B Light beam P Reference point

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G21C 17/013 B62D 57/02 D 19/02 G21C 17/00 H

Claims (1)

[Claims] 1. A method of positioning a submersible mobile robot which adsorbs on a vertical wall of a pressure vessel filled with reactor water and moves tracklessly along the vertical wall, wherein an arbitrary reference point in the reactor water and the robot body are provided. Each of them is equipped with a water depth gauge to measure the water depth, and the vertical position of the robot body with respect to the pressure vessel is measured from the difference in water depth detected by these water depth gauges. A quantity sensor is provided, a light beam is emitted from this light beam projector in the direction of the internal structure whose position is known in advance, and the horizontal position of the robot body is detected from the amount of reflection, and the vertical direction A positioning method for an underwater mobile robot, characterized in that the position of the underwater mobile robot with respect to the pressure vessel is determined from a position and a horizontal position.