Control of sliding-isolated buildings using sliding-mode control

Based on the theory of continuous sliding-mode control, control methods are presented for seismicexcited buildings isolated by a frictional-type sliding-isolation system. The dynamic behavior of the building equipped with a base-sliding-isolation system is highly nonlinear, and the sliding-mode-control method is ideal for such nonlinear systems. In addition to full-state-feedback controllers, a simple static-output-feedback controller using only the measured information from a few sensors installed at strategic locations without an observer is presented. The continuous sliding-mode controllers presented do not have undesirable chattering effect. Simulation results for an eight-story building indicate that (1) the control methods are robust; and (2) the control performance is outstanding. A shaking-table experimental program was conducted to verify the proposed static output control method. For the shaking-table tests, a three-story quarter-scale building model was mounted on a base mate that was supported by four frictional bearings. Experimental test results indicate that the control performance is quite remarkable, although a slight degradation was observed due to noise pollution and system time delays.