Development and experimental study of a vibration controller for a robotic system interfaced with machining operations.
Robotic arms are used extensively in machining applications due to a large working envelope and easy access to restricted areas. However, low stiffness of the robot arm caused by joint flexibility introduces additional degrees-of-freedom and vibration modes, which leads to the deterioration of positioning performance. To attenuate these induced motion tracking errors and vibrations, this research presents the development and experimental study of an adaptive control scheme, which combines a state feedback and an adaptive feedforward controller to shape robot dynamics into a desired dynamics that does not produce link oscillations. The proposed method is demonstrated on a six-joint robot manipulator, namely SCOMPI developing at Hydro-Québecs research institute, performing machining tasks in situ maintenance of hydro turbine runners. Reliability and robustness of the proposed method allow the SCOMPI robot to maximize machining performance and to move SCOMPI technology forward over competitive products.