Experimental examination of non-stationary robust vibration control for an elevator rope

In this paper, a method to suppress the transverse vibrations of an elevator rope is verified through an experimental approach and its feasibility for practical use is explored. Since the elevator rope has time-varying characteristics and flexibility, it is difficult to reduce its vibrations caused by the resonance due to building sway using conventional active control methods. Therefore, the vibration control problem of elevator rope is resolved using a non-stationary robust control method in this research. The proposed method positively considers the time-varying parameters due to the change in length of the elevator rope and the uncertainties due to modelling errors. The suppression device for the vibrations of the elevator rope is deployed by the traction sheave located at its boundary to control movements through the experiments. Furthermore, time-varying output feedback control is performed with a few sensors using an estimator. In addition, solutions are developed to resolve practical problems such as the packaging of the time-varying controller and the compensation for frictions in an actuator system.