Stable, Sensor-less and Compliance-less Module Connection for Automated Construction System of a Modularized Rail Structure

Abstract

Unmanned robots have been proposed for the decommissioning of Fukushima Dai-ichi Nuclear Power Plant. To achieve efficient movement of robots in the high-radiation environment, we propose an “automated construction system of a modularized rail structure.” In the high-radiation environment, the rail structure must be constructed by a remotely controlled robot using minimal sensors. In addition, a compliant mechanism that allows small misalignments is not feasible in the module connection task due to multiple load conditions. Therefore, this study aims to achieve stable, sensor-less, and compliance-less construction using a remotely controlled robot. To achieve this goal, a geometrical model of a connection mechanism is generated and used for contact analysis of the kinematic chain transition. An analysis of the relative angle and distance between the connection surfaces of the modules effectively illustrates the conditions of connection success and failure. Based on the analysis results, the design is modified to stabilize the connection task and employed to update the constructor robot. Thus, the stability of the module connection is improved, even under various load conditions.