Robust DOBC for Stabilization Loop of a Two-Axes Gimbal System

In this paper, a disturbance compensation strategy based on disturbance observer control (DOBC) is proposed to solve parameter perturbation, friction, coupling and external turbulence for two-axes gimbal control system. Uncertainties, friction, coupling shortcoming of gimbal system is summed up as a disturbance suppression problem, and achieving disturbance compensation through feedforward channel of DOBC. However, the compensation effects of DOBC are determined by modeling accuracy of the nominal plant and feedforward filter design. A H∝-based filter design is adopted to guarantee robust stability of DOBC when controlled object changed. Because performance weight function of DOBC is derived from stable constraint of closed-loop system, and robust of closed-loop system can also be satisfied. Eventually, we completed proof of H∝-based robust DOBC algorithm in pod system, and stability performance of the system has been greatly improved.