Analysis and Control of Quasi Distributed Parameter Systems

Citation

Goh, Chuen Jin (1983) Analysis and Control of Quasi Distributed Parameter Systems. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/96PH-6521. https://resolver.caltech.edu/CaltechETD:etd-08092005-091223

Abstract

As engineering systems become larger and more flexible, serious consideration must be given to the very high order, and consequently very high bandwidth, of these so called quasi-distributed parameter systems. In particular, as practical active control devices such as sensors and actuators have finite bandwidth, great care must be exercised so that control of low frequency modes does not cause instability of intermediate and high frequency modes. In this report, the nature of these stability problems is investigated in the context of direct velocity feedback control, and approximate bounds on the diagonal elements of the modal gain matrix are derived. Two velocity feedback techniques are proposed to alleviate potential instability, but these are dependent on the natural damping of the system, which remains uncertain in practice. Another technique using position feedback is considered. Despite certain additional complications, position feedback control proves to be more advantageous in many ways than velocity feedback. Some preliminary analyses on a quasi-linear vibration suppression technique via damping matrix modification are also presented. The feasibility of these theoretical techniques are confirmed by means of a numerical simulation on a simply supported discrete shear beam.

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