Optimization of an actuated flexible arm for improved control properties

A multi-objective optimization index is introduced for improving the dynamic behavior of an actuated structurally flexible arm through geometric shape design. The improvement in the dynamic behavior is achieved by defining a vector optimization cost function. This cost function is associated with the frequency of the lowest system zero when joint angles are taken as outputs, the gain sensitivity of the open-loop system modes, and the gain sensitivity of the closed-loop system modes at its transmission zeros. The cost function is utilized to optimize the structural shape for a single-link flexible arm. The optimized link is shown to yield superior robustness and performance characteristics in a closed-loop system when compared to the non-optimized uniform link