Simultaneous Optimum Design of Structure and Control Systems based on Closed Loop Pole Assignment.

Abstract

This paper aims at proposing a new simultaneous optimum design method of structure and control system: such as several types of mechanical systems equipped with vibration control system in order to suppress the structural vibration of the mechanical system. When the proposed method is applied to the design of a structure-control combined system, the closed loop pole assignment of the lower order model of the combined system is specified in advance as a design requirement. Proposed method is constructed from two steps: in the first step, output feedback control system is designed for the initial structure in order to realize the specified closed loop pole assignment; and next step, structure and control system design parameters are simultaneously optimized to minimize the objective function subject to constraints on the pole assignment. Scalar objective function is defined as a linear combination of several measures of the optimality of structure design and control system design. According to the proposed method, the closed loop pole assignment of the lower order model is preserved through the iterative optimum design process. The effect of the proposed method will be shown by the numerical simulation results of the cantilever beam design example. Not only structural configuration but also control system are successfully optimized under the objective function minimization.