Research on an Extended State Observer based Self Tuning Control Strategy for a Two-axis Four-gimbal Servo System

In this paper, it is concerned to improve the control performance and the disturbance rejection ability of a two-axis four-gimbal system performance. An improved control structure is designed that the outer gimbal works as a positon servo system following inner gimbal, and a stabilization loop is introduced into the outer gimbal to strengthen the performance of disturbance rejection. Moreover, a pole placement self-tuning control (STC) algorithm with the extended state observer (ESO) is proposed. The ESO is applied to observe and compensate both torque and carrier angular rate disturbance. Simulation results demonstrate the effectiveness of the proposed method.