Decoupling flight control synthesis to helicopter in hover condition with unstructured uncertainty

This paper presents a synthesis of the decoupling compensator for multiinput multioutput systems with considerations of the robust stabilization. The restriction of constant pole number for a controlled plant with uncertainty from small gain theorem is relaxed as the robustness is considered. Both the nominal plant and the uncertain plant with varying numbers of right half plane poles could be stabilized internally and simultaneously after decoupling. The two-parameter compensator is also employed with output feedback. Furthermore, the H^∞ sub-optimal compensator can be achieved with the robust criterion of the normalized coprime factor plant. The robust bound of the system with the synthesized compensator is also evaluated. Furthermore, all the necessary state space formulae of the robust-decoupling compensator are provided. This approach will be applied to a rotorcraft flight control in hover condition. The decouple objective is achieved with internal stability. The robustness of the system is also conserved even in the severe conditions, plant with different RHP pole number with the uncertainties. The simulation illustrates the results that are inspired by the compensator synthesized in this paper.