Research of NSMDOB-Based Compound Control for Photoelectric Tracking Platform

Disturbance compensation is an important criteria to evaluate the performance of a photoelectric tracking servo control system. In order to effectively compensated disturbance in high frequency, a novel sliding mode disturbance observer (NSMDOB) is proposed in this paper. The dynamic performance of the system is improved by the design of the compound control scheme with the NSMDOB and additive decomposition theory. According to the additive decomposition theory, the photoelectric tracking platform servo system was decomposed into the main system and the auxiliary system. The tracking control and disturbance compensation were considered respectively in two systems. A rapid switching technique of the sliding mode was used to estimate the high frequency disturbance in the NSMDOB and the compensator of the auxiliary system. Finite-time control (FTC) was used to design the sliding mode compensator, which could maintain the state of auxiliary system asymptotically stable. Experiment results prove that the proposed method may offer the fast convergence rate, the high tracking accuracy, and the strong robustness of the control system.