Nonlinear sliding-mode controller for sensorless speed control of DC servo motor using adaptive backstepping observer

In this paper, the robust nonlinear sliding-mode speed sensorless speed controller for a dc servo motor is proposed. Based on state-space model representing the speed and current dynamics, the nonlinear sliding mode control is designed to track a linear reference model. An observer based on adaptive backstepping approach is used to estimate speed and uncertain parameters. With the proposed speed controller, the controlled dc servo motor possesses the advantages of good transient performance and robustness for parameters deviations, and transient dynamics of dc servo motor can be regulated through the design of a linear reference model which has the desired dynamic behaviors for the drive system. Finally, simulation results are demonstrated to validate the proposed controller.