Katsumi Kubo

Development of Nuclear Power Plant Automated Remote Patrol System

Abstract An Automated Remote Patrol System was developed for a remote inspection, observation and monitoring of nuclear power plant’s components. This automated remote patrol system consists of; a vehicle moving along a monorail; three rails mounted in a monorail for data transmission and for power supply; an image fiber connected to a TV camera; an arm type mechanism (manipulator) for moving image fiber; a computer for control and data processing and operator’s console. Special features of this Automated Remote Patrol System are as follows: 1. The inspection vehicle runs along horizontal and vertical (up/down) monorails. 2. The arm type mechanism (manipulator) on the vehicle is used to move image fiber. 3. Slide type electoric collectors are used for data transmission and power supply. 4. Time-division multiplexing is adapted for data transmission. 5. Voice communication is used for controlling mechanisms. 6. Pattern recognition is used for data processing. The experience that has been obtained from a series of various tests is summarized.

Monitoring and Analysis of Welder's Behavior in Manual Welding

Abstract Welding is an essential process in fabricating a variety of products in industry. Although most of the welding works have already been automated, high reliability of the manual welding fabrication is still demanded. In this paper the necessity of the in-process monitoring of manual welders performance is addressed in order to clarify the skill for manual welding in workshop. The behavior of welders at different skill levels during manual welding fabrication was monitored. It was confirmed through the analysis that the parameters like movement of the welding torch and the viewpoint of the welders appropriately reflected the welders skill level.

Visualization of diffused gases in an open space using photoacoustic technique

A new method, using the photoacoustic technique, is proposed for detection and location of gases leaked to an open space. Photoacoustic signals which are emitted by laser/gas interaction along a laser beam have a typical frequency of 40kHz and travel along the perpendicular to the laser beam. Arrayed ultrasonic microphones are used to locate a sound sources on the laser beam; a two-dimensional laser scanning mechanism is employed to reconstruct the distribution of a diffused gas. Applying the method, a three-dimensional distribution of leaked methane gas to an open space is successfully visualized.

Real-time processor for 3-D information extraction from image sequences by a moving area sensor

This paper presents a real time image processor for obtaining threedimensional( 3-D) distance information from image sequence caused by a moving area sensor. The processor has been developed for an automated visual inspection robot system (pilot system) with an autonomous vehicle which moves around avoiding obstacles in a power plant and checks whether there are defects or abnormal phenomena such as steam leakage from valves. The processor detects the distance between objects in the input image and the area sensor deciding corresponding points(pixels) between the first input image and the last one by tracing the loci of edges through the sequence of sixteen images. The hardware which plays an important role is two kinds of boards: mapping boards which can transform X-coordinate (horizontal direction) and Y-coordinate (vertical direction) for each horizontal row of images and a regional labelling board which extracts the connected loci of edges through image sequence. This paper also shows the whole processing flow of the distance detection algorithm. Since the processor can continuously process images ( 512x512x8 [pixels*bits per frame] ) at the NTSC video rate it takes about O. 7[sec] to measure the 3D distance by sixteen input images. The error rate of the measurement is maximum 10 percent when the area sensor laterally moves the range of 20 [centimeters] and when the measured scene including complicated background is at a distance of 4 [meters] from

DEVELOPMENT OF NUCLEAR POWER PLANT AUTOMATED REMOTE PATROL SYSTEM

An Automated Remote Patrol System was developed for a remote inspection, observation and monitoring of nuclear power plants components. This automated remote patrol system consists of; a vehicle moving along a monorail; three rails mounted in a monorail for data transmission and for power supply; an image fiber connected to a TV camera; an arm type mechanism (manipulator) for moving image fiber; a computer for control and data processing and operators console. Special features of this Automated Remote Patrol System are as follows: 1. The inspection vehicle runs along horizontal and vertical (up/down) monorails. 2. The arm type mechanism (manipulator) on the vehicle is used to move image fiber. 3. Slide type electoric collectors are used for data transmission and power supply. 4. Time-division multiplexing is adapted for data transmission. 5. Voice communication is used for controlling mechanisms. 6. Pattern recognition is used for data processing. The experience that has been obtained from a series of various tests is summarized.