An insightful approach to H∞ position controller design for an electric motor attached to a flexible structure

Although there is much literature concerning the control of electric motors, less attention has been devoted to the practical problem of controlling electric motors when they are attached to mechanical supports with structural resonances that interact with the controlled motor. This paper focuses on the use of classical Bode analysis techniques to gain insight into the development of an H_∞ controller for an electric motor attached to a flexible structure. Bode plots are used to provide a meaningful guide to adjusting control weightings in the H_∞ problem formulation such that performance objectives are achieved. This approach is applied to the inertial position regulation of a gimballed pointing payload with significant structural resonances. Both theoretical and real-time experimental results are presented