Application of nonlinear observers for elevator vibration control

In this paper, an application of an extended nonlinear observer is introduced in order to implement a vibration suppression controller for an elevator. A proposed observer enables the observation of system states and the identification of system parameter simultaneously. The estimation of the cage acceleration and the identification of rope parameter are obtained by an extended nonlinear observer and using this acceleration signal a vertical vibration suppression controller is designed for a good ride quality. The two nonlinear observers are presented and compared by computer simulation based upon the linearized elevator model. Simulation proves the feasibility of a speed controller with a vertical vibration suppression controller.