Enhanced Resolver Angle Tracking Observer via Error-Input Active Disturbance Rejection Control

This paper proposes an angle tracking observer based on a first-order decoupled active disturbance rejection controller with error input (FDADRC-ATO) to eliminate the steady-state position error in resolver soft decoding during the acceleration process of permanent magnet synchronous motors. Due to uncompensated higher-order dynamics, the traditional PI-ATO exhibits a steady-state error of 0.56° under uniform acceleration. The FDADRC-ATO offers three advantages: first, direct angular error input; second, an enhanced first-order ESO for zero-error angle tracking without additional phase delay; third, single bandwidth parameter tuning. Theoretical analysis confirms that compared to error-input SADRC-ATO and ESDOF-ADRC-ATO, the position tracking bandwidth is increased while phase lag is reduced. The simplified structure ensures efficient MCU implementation, providing high-dynamic position sensing for permanent magnet synchronous motor drives.