Abstract:

Robust vibration control of lightweight flexible structures, in recent years, has been a subject of interest in both research and industry, particularly in the aerospace field. Flexible structures, such as spacecraft and robots, are constrained by permissible deflection levels, of their flexible appendages, which ensure they are not permanently deformed during a maneuver. The methods developed in this thesis provide controller designs for a wide range of slewing structures and are robust to model uncertainties.

The focus of this thesis is on the design of time optimal control strategies which limit the maximum magnitude of transient deformation experienced in a maneuvering flexible structure. Essentially this thesis consist of three primary sections. Firstly, deformation-limited control strategies for rest-to-rest maneuvering of undamped structures are developed. Analytical and numerical approaches are formulated and the proposed techniques are studied on benchmark problems. In the second section, a thorough investigation on the effects of structural damping is performed and studied across a vast span of damping coefficients. The third section introduces several methods for ameliorating the robustness of the deformation-limited time-optimal control strategy; traditional robustification methods and minimax approaches are performed.