Robust two-degree-of-freedom H∞ control of a seeker scan loop system

A parameter-dependent model of a seeker scan loop system is introduced. A new approach to modelling real-valued parameter uncertainties and designing H_∞ robust controllers is presented, considering the effect of parameter uncertainties on closed-loop stability and performance, which is formulated within the framework of the standard H_∞ optimisation problem by combining the conventional mixed sensitivity and model-matching problems with the robust stability problem. The proposed design procedure is applied to a seeker scan loop system with uncertainties in three parameter values. It is shown that the designed two-degree-of-freedom H _∞ controller offers good performance and robustness properties, and that the proposed design scheme is very effective for the robust control of a seeker scan loop system