Senior Seismic Response Stochastic Optimal Control Study

Active structural control technique has shown promising prospect in the field of earthquake/wind resistane. However, more researches on theoretical problems and practical implement consideration are to be developed before the technique is extensively applied to actual engineering. In this dissertation, theoretical problems of active control of tall building stuctures under strong earthquake are studied.First, for state feedback control system all state variables should be obtained so as to materialize state feedback control. Since the number of state variables is large for tall building structures, measuring all those state variables will lead to a huge sophisticate measure system. In order to surmount the technical difficulty application of state observers to structural control is discussed , and full/reduced order state observers with external excitation driving term which is distinguished from classical observers are investigated. Those observers can be incorporated in computers which act as control pivot. So observers will not necessitate an additional complicate measure system. Based on theory of structural dynamics and differential equation, the requirement of state complete observability is infered related to vibration modes, which is more acceptable for engineering than the counterpart of modern control theory related to rank of matrix in algebra. On the light of requirement sensors can be conveniently arranged to guarantee state observability. Analysis of closed loop system has demonstrated that classical Luenberger observers without external excitation driving term are not appropriate to structural control systems.Second, stochastic optimal structural control under earthquake excitation is investigated in discrete time form. In the case of complete information, instantaneous optimal control law with respect to time variant index functional is developed. As this control law needs much less compuation and storage than linear quadratic optimal control law, it is especially suitable for vibration con-...