Active seismic isolation by disturbance-accommodating gain-scheduled control

In this paper, we propose a design method of a disturbance-accommodating gain-scheduled control taking account of actuator saturation by seismic excitation in vibration isolation for a multi-degree-of-freedom structure. A disturbance model multiplied by an envelope function is introduced for distrubance-accommodating control in order to represent the nonstationary characteristics of seismic disturbance. We formulate a linear parameter varying system according to the amplitude of the disturbance as well as the controller output, and design a gain-scheduled controller. By carrying out simulations and experiments of seismic excitation, it is verified that the proposed controller can maintain the performance of isolation even if a large earthquake with which actuator saturation occurs comes.