Design of mixed sensitivity H_∞ control for four-rotor hover vehicle

During the past one decade, multirotor unmanned aerial vehicles (MUAVs)'s control has become an active research area for flight control community. The reasons behind are the benefits offered by MUAV and its numerous commercial and consumer applications. In this paper, design of a robust attitude controller for four-rotor hover vehicle that is a kind of MUAV, based on H∞ mixed-sensitivity synthesis is presented. Firstly, a linear model of four-rotor hover vehicle is derived, which is formulated as a nominal plant perturbed by parameter and unstructured uncertainties. H∞ mixed-sensitivity controller is designed due to the uncertain nature of the system. The efficacy of the proposed controller is proved by simulations and experiment. Performance analysis, simulation, and experimental results show that the proposed controller guarantees stability, exhibits good performance, and robustness margins against the parameter and unstructured uncertainties.