In this paper, we propose a pipe inspection robot to move automatically along the outside of piping. In recent years, such pipe inspection robots and climbing robots have been the subject of important research activity worldwide [1]-[3]. Inspection of industrial pipe is a well-known and highly practical application of robotic technology. Robots especially designed to inspect the surface of pipe have recently been realized by some companies, and are in practical use as mechanical pipe inspection devices in various plants. Some of the robots have the capability of self-propelled inspection. These robots are equipped with ultrasonic diagnostic equipment that can measure the thickness of the pipe along its surface [4]. However, they are able to move by manual operation only. Such robots cannot be applied to pipes with flanges and valves, etc. We have designed a mechanism that enables robots to traverse flanges, rise along vertical flanges, and move along the underside of the piping [5]-[8]. The proposed robot is composed of three connected units.

In an industrial plant, straight piping, vertical piping, curved piping, valves, and flanges are arranged in complex patterns. Problems regarding automated pipe inspection originate in the fact that sensors cannot scan complex piping schemes involving flanges, valves, curved piping, and vertical piping. Various types of pipes are used in industrial applications, taking into consideration the temperature and the corrosive properties of the fluid. Oil plants, for example, use mainly carbon steel, stainless steel, and chloridized vinyl pipes. In light of this, we have focused on developing a robot that can inspect carbon steel pipes, having the ability to move automatically along the outside of a length of piping. This paper describes the structure of magnetic wheels used in a pipe inspection robot. We propose a robot that has a mechanism consisting of wheel-type magnets. Using the power generated by the magnets, the robot maintains its attachment to the pipe. The mechanism of the robot is composed of three units, and is able to automatically inspect a pipe's surface, traverse flanges, and rise along vertical piping. To achieve the robot's optimum performance, the design of the magnetic wheels is important. The authors have previously designed a similar robot composed of three connected units, though the adherence power of this robot was weak and could not achieve a high level of stability while advancing along a straight length of pipe.

In this paper, we propose a robot which detects dangerous articles made of plastic. To detect plastic articles, a corona charger is installed on a robot. The corona charger consists of corona wire through which high voltage is charged. The dangerous articles are identified by the detection of different surface potential by the difference of the electrification series when the corona is applied to the object. A vehicle was developed as a prototype machine. This vehicle has two driving systems; one is the mechanism with two motors and four castors, another one is a motor which moves the sensor up and down.

A tactile sensor, which has a flexible structure for measuring contact force, is presented. This sensor has two strain gages, which measure the deformation of this sensor. This sensor can estimate a contact location and amount of contact force. A model of flexible deformation was described by stiffness equations, which include several geometric parameters of the sensor. The model was simulated and compared to experimental data. The comparison shows that the model can accurately estimate a contact location and the amount of contact force. Additional results of the model were compared with experimental data that is assumed to apply in a real environment. As the result, accuracy of the estimated results is under 10% when an upper limit is fixed.

The integrity in components of an operating nuclear power plant (NPP) is usually monitored on a daily basis by operator patrols. Currently, there is a pressing need to replace such human patrol activities by systems of automated monitoring in order to reduce radiation exposure and the workload imposed on operators. From this perspective, and under the sponsorship of the Ministry of International Trade and Industry (MITI), we embarked upon a R&D project in 1991 with the objective of developing TOSHIBA Remote Inspection System (TOSRIS) for NPPs. We built a prototype system and examined it in a mockup of a typical NPP environments. This project was completed in 1996. This paper describes the concept of TOSRIS, how the inspection position is calculated, how plans are passed using a 3D-CAD database, and mockup tests.

The integrity of components of an operating nuclear power plant (NPP) is usually monitored on a daily basis by operator patrols. Currently, there is a great need to replace such human patrol activities by systems of automated remote monitoring in order to reduce radiation exposure and the severe workload imposed on operators. From this perspective, and under the sponsorship of Ministry of International Trade and Industry (MITI), the authors embarked upon a R&D project in 1991 with the objective of developing an autonomous mobile patrol system for NPPs. The project is scheduled to be completed in 1996. This paper describes the concept of the autonomous mobile robot system, which comprises a hierarchical autonomous mobile control system, a localization system based on pattern matching between the data profile from a laser rangefinder and an environment map, a method of constructing environment maps from 3D-CAD of a NPP, and a cableless robot system.