Numerical Optimization, System Theoretic and Software Tools for the Integrated Design of Flexible Structures and Their Control Systems.

Abstract

Abstract : This research was motivated by a growing consensus that design specifications for projected controlled flexible aerospace structures, which are becoming larger and more flexible while performance requirements are becoming more stringent, can only be satisfied through an integrated design approach in which one determines simultaneously both structural and control system parameters. The work dealt with nonsmooth optimization techniques for the integrated design of flexible structures and their control systems. Nonsmooth optimization is an ideal tool for integrated design because it allows dynamic constraints and imposes no distinction between control system and structural variables. Major accomplishment include the development and testing of an optimal control algorithm which can be used to solve both free and fixed time optimal control problems, such as the problem of moving a flexible structure, modeled by a partial differential equation, from an in initial to a final position in minimum time, while guaranteeing upper bounds on the controls and deformations of the structure over the entire maneuver; and laying the ground-work for the frequency domain design of finite dimensional feedback controllers for flexible structures, without resorting to modal truncation and suffering the resulting spillover effects.