Self-Attenuating Real-Time Vibration Control of a Flexible Long-Reach Robot Manipulator via Η Synthesis
We address the critical challenge of vibration con trol of flexible long-reach robot manipulators used in nuclear decommissioning. The research is motivated by the urgent need to ensure precision and safety during the deployment of robotic systems in confined and hazardous environments, such as the through-wall deployment (TWD) system for the Sellafield nuclear site. The TWD system, featuring a rigid manipulator on a flexible two-link boom, is designed to maneuver through small openings in containment vessels. While this design avoids the need for bulky structures, the slenderness of the boom makes it prone to significant vibrations, potentially compromising the system’s stability and accuracy. To address these challenges, we propose a novel real-time flexible control system that suppresses vibrations using only the robot manipulator’s own actuation, without requiring additional actuators. The control strategy is based on the mixed-sensitivity H∞ synthesis for a dedicated dynamics model via inertial sensing, enhancing the robustness and adaptability over the multi-modal flexibilities. Experimental validation demonstrated the control system’s effectiveness in reducing vibrations, thereby improving operational efficiency and safety. These findings have broader implications for deploying flexible, intelligent control systems in other high-stakes envi ronments, such as the Fukushima Daiichi site, where similar vibration-related challenges are encountered.