Control of Parallel-Link Robot Manipulator for Pipe-Flaw Diagnosis

Abstract

We have developed a Pipe-Diagnostic Robot System with Ultrasonic Sensor. The robot is able to detect the flaws at the elbows in addition to strait pipes. This robot is composed of a six-link parallel mechanism, a ring-rail and a diagnostic end-effecter which has a ultrasonic probe. In order to measure the thickness of pipes accurately, it is important to adjust the posture of the ring-rail to the pipe elbow geometry, and to contact the ultrasonic probe to the surface of pipes closely. We have introduced schemes to control the position and posture of the ring-rail and to judge the status of the probe's contact, and shown the results of the experiments.