Self-Calibration Method for RDC System of Gimbal Servo System in SGCMG Based on Signal Reconstruction

Accurate angular position detection is indispensable for high-precision angular speed output of the gimbal servo system in single gimbal control moment gyro (SGCMG). However, the nonideal characteristics of resolver output signals introduce systematic errors in angular position detection, consequently impacting the accuracy of gimbal angular speed output. The compact structure of SGCMG prohibits the attachment of high-precision sensors for resolver calibration due to space constraints. Therefore, a self-calibration method based on signal reconstruction is proposed to suppress the resolver systematic error. The angular speed control error is fed into the co-frequency notch filter for iterating. Subsequently, the sine and cosine coefficients of the systematic error are identified, and the coefficient tables are established. The systematic error is then reconstructed according to the coefficient tables and compensated in the angular position feedback link. Simulation analysis is employed to assess the stability and dynamic performance of the closed-loop system. Experimental verification confirms that the proposed method can effectively suppress the systematic error of the resolver and improve the angular position detection accuracy, which further improve the precision of the gimbal angular speed.