Precise position control using a PMSM with a disturbance observer containing a system parameter compensator

A deadbeat load torque observer with a system parameter compensator that can be used to improve the performance of a permanent-magnet synchronous motor in a precision position control system is presented. The compensator makes real systems work as it in a nominal parameter system. Therefore, the observer has a performance level equivalent to that obtained if there is no parameter variation. Noise effects are reduced by the use of past-filter implemented using a moving-average process. A comparison study on the system response for a convertional deadbeat gain observer and the proposed parameter-compensated deadbeat observer is performed. The proposed system can be used to cancel out any steady-state or transient position errors created by external disturbances such as friction, load torque or chattering effects.