IMPROVED CONTROL DESIGN VARIABLE LINKING FOR OPTIMIZATION OF STRUCTURAL CONTROL-SYSTEMS

A method is presented to integrate the design space for structural/con trol system optimization problems in the case of linear state feedback control. To make the truly simultaneous optimization of structural/co ntrol systems tractable, without increasing the number of control desi gn variables, the conventional structural design variable linking ides is extended to the control system feedback gain matrix. In this paper a new control design variable linking scheme based on representing th e feedback gain matrix as the linear combination of component matrices corresponding to different modes is introduced. The original nonlinea r mathematical programming problem based on a finite element formulati on and linear state feedback is replaced by a sequence of explicit app roximate problems exploiting various approximation concepts such as st ructural and control design variable linkings, temporary constraint de letion, and first-order Taylor series expansion of nonlinear behavior constraints in terms of intermediate design variables. Examples that i nvolve a variety of dynamic behavior constraints (including constraint s on closed-loop eigenvalues, peak transient displacements, and peak a ctuator forces) are effectively solved by using the improved control d esign variable linking scheme presented.