Robust Position Control of a Synchronous Motor Using Discrete Sliding mode Model Following Controller

A synchronous motor position control system using a discrete sliding mode model following control or DSMFC is presented to achieve accurate tracking in the presence of load disturbance and plant parameter variations. The DSMFC algorithm uses the combination of model following control and sliding mode control to improve the dynamics response for command tracking. A design procedure is developed for determining the control function, the coefficients of the switching plane and the integral control gain. The control function is derived to guarantee the existence of a sliding mode. A DSP-based synchronous motor position control system using the DSMFC approach is illustrated. Experimental results indicated that DSMFC system performance with respect to the sensitivity to parameter variations is greatly reduced. Also, its can achieve a rather accurate tracking and is fairly robust to load disturbances.