A Comparative Study of Simple Dynamic Models and Control Schemes for Elastic Manipulators

Maniplators with highly elastic links are currently being studied for both terrestrial and space applications. As opposed to manipulator with rigid links, however, elastic manipulators have extremely complex dynamical behaviors and require sophisticated control schemes. The purpose of this investigation is to study modeling techniques and control algorithms for elastic manipulators. In this study, a one-link elastic manipulator is modeled using both lumped-parameter and assumed-modes methods. Equations of motion for two lumped-parameter models are derived using the multibody dynamics program AUTOLEV, and those of a distributed-parameter model are formulated manually with Kane's method. These equations are incorporated into simulation programs to evaluate the performance of various control schemes. The results obtained from this investigation provide insights into the issues and problems involved in modeling and controlling the motions of elastic manipulators.