Compensation of time-delay for control of civil engineering structures

Time-delay is an important issue in structural control. Applications of uns ynchronized control forces due to time-delay may result in a degradation of the control performance and it may even render the controlled structures t o be unstable. In this paper, a state-of-the-art review for available metho ds of time-delay compensation is presented. Then, five methods for the comp ensation of fixed time-delay are presented and investigated for active cont rol of civil engineering structures. These include the recursive response m ethod, state-augmented compensation method, controllability based stabiliza tion method, the Smith predictor method and the Fade approximation method, all are applicable to any control algorithm to be used for controlled desig n. Numerical simulations have been conducted for MDOF building models equip ped with an active control system to demonstrate the stability and control performance of these time-delay compensation methods. Finally, the stabilit y and performance of the phase shift method, that is well-known in civil en gineering applications, have also been critically evaluated through numeric al simulations. Copyright (C) 2000 John Wiley & Sons, Ltd.