Speed Control of DC Motor using Electrorheological Brake System

This study presents robust control performance of a direct current (DC) motor with brake system adopting the giant electrorheological (GER) fluid, whose distinguished feature is an extremely high value of yield stress. As a first step, Bingham characteristics of the GER fluid is experimentally investigated using the Couette type electroviscometer. A cylindrical type of electrorheological (ER) brake is then devised based on the Bingham model, and its braking torque is experimentally evaluated. The ER break is then incorporated with a DC motor. After formulating the governing equation of motion for the DC motor with ER brake system, a sliding mode control algorithm, which is very robust to external disturbances and parameter uncertainties, is synthesized and experimentally realized in order to achieve desired rotational speed trajectories. The tracking responses of the control strategy are then evaluated for various sinusoidal trajectories. In addition, their tracking errors are evaluated and compared with those obtained from traditional PID controller.