Multimode Control of a Large-Scale Robotic Manipulator

In this paper, the application of a piezoelectric stack actuator for vibration control in a large-scale robotic manipulator, called a macromanipulator, is studied. In this regard, mechanical design and mathematical modeling of the actuator are discussed. The structural flexibility of the macromanipulator includes deflection and torsional vibration modes. The vibration modes are detected using appropriate sensor attachments. Furthermore, a nominal transfer function matrix between the input signals to the actuators and the output voltages of the sensors is obtained. A closed-loop controller based on the obtained model is designed. Because of the presence of deflection and torsional vibration modes and model uncertainties resulting from manipulator motion, an robust controller is utilized. Experimental results are presented to validate the robustness and performance of the designed controller.