Evaluation of Control Methods on a Structural System

In this study, PID, LQR and sliding mode controllers are designed as active seismic isolation devices on a multi degrees of freedom structure. At first PID control is applied as a conventional method. Since this control method can be applied easily and well known widely, it has an important role in control applications. Secondly, a LQR is designed to suppress the vibrations of the structural system. But these methods are not insensitive to parameter changes. Since the model might have uncertainties and/or parameter changes. sliding mode control has been introduced because of its well-known robust character and superior performance. Additionally, this control method can easily be applied to non-linear systems. The simulated system has four stories. A disturbance input representing earthquake is applied to the base. At the end of the study, the Lime history of the storey displacements, control voltage and frequency responsc of the both uncontrolled, PID, LQR and sliding mode controlled structures have been presented and results have been compared.