OUTPUT-FEEDBACK SLIDING-MODE CONTROL WITH GENERALIZED SLIDING SURFACEFOR CIVIL STRUCTURES UNDER EARTHQUAKE EXCITATION

The paper presents a control scheme based on the sliding-mode-control approach. The analytical formulation focuses on the development of (1) a convenient, systematic and general scheme to achieve the so-called regular form of the equations of motion required to uncouple the contr ol actions from the sliding motion description, (2) a systematic treat ment of control redundancy where the number of sliding constraints imp osed are less than the number of independent control actions, and (3) a method to improve sliding surface design by incorporating auxiliary dynamic systems. Both full-state-feedback and output-feedback cases ar e considered. In the output-feedback formulation, a generalized proced ure is developed so that arbitrary combinations of unavailable system states (unmeasured displacements or velocities, for example) need not participate in the design of the sliding surface or the controller. A controller design utilizing only bounding information on the intensity of ground motion and the unmeasured states is proposed. The analytica l formulation developed herein is applied to a 10-storey building stru cture to obtain the numerical results. The advantages of introducing a uxiliary systems in the design of the sliding surface and the correspo nding controller are noted. The results for both full-state-feedback a nd output-feedback cases are presented and compared to demonstrate app licability of the proposed control scheme. (C) 1998 John Wiley & Sons, Ltd.