Auto-compensation of torque ripple of DD motor by torque observer

A torque control system for DDM (direct drive motor) with a permanent magnet rotor equipped with a torque observer implemented by software of a digital signal processor is proposed. The speed fluctuation against a disturbance can be fully removed with a torque feedforward loop. It is shown that the direct motor control system with a torque observer gives a superior speed control characteristics. Furthermore, the system has a robustness against disturbing torque and a variation of mechanical parameters.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>