Active seismic isolation control taking account of actuator saturation

In this paper we propose a design method for active seismic isolation control taking account of actuator saturation. By using a hyperbolic tangential function that is differentiable to controller output, we formulate the linear parameter varying system according to the controller output and design a gain-scheduled controller. By carrying out simulations and experiments of seismic excitation, our proposed gain-scheduled controller is compared with an H∞. fixed controller or a sliding mode controller. It is verified that the proposed controller maintains performance of isolation even if a large earthquake with which the actuator saturation occurs comes, although the other controllers lower the performance than uncontrolled case.