Sliding Mode Control of Hysteretic Structural Systems

Sliding mode control systems have been recognized to be robust in the presence of exogenous perturbations. For a sliding mode control design, a known upper bound of the perturbation is usually assumed. In this paper, we present an adaptive algorithm for the estimation of this upper bound, and consequently there is no need for the exact knowledge of this quantity. Moreover, we have applied the proposed controller for the perturbation rejection of seismically excited hysteretic structural systems. A key contribution presented in this work is that, although the hysteretic structural system considered is a nonlinear third-order model, the sliding mode control has been designed using a reduced second-order dynamic system. The performance and robustness of the controller are then analyzed by means of numerical simulations.