Robust control of small-scale unmanned helicopter with matched and mismatched disturbances

In this paper, a novel robust control method for small-scale unmanned helicopter with matched and mismatched disturbances is investigated. The control objective is to make the helicopter track the predefined position and yaw angle reference trajectories. First, the helicopter model is linearized with approximate feedback linearization technique. Then, by using the estimation of the mismatched disturbances and their derivatives, the helicopter system is reconstructed to an equivalent system, where the mismatched disturbances are turned into the major matched component and minor mismatched component. These disturbances are suppressed by feedforward technique and H∞ feedback control algorithm. Finally, simulation results demonstrate the effectiveness and robustness of the proposed control strategy for small-scale unmanned helicopter in the presence of both matched and mismatched disturbances. The proposed novel robust control method can attenuate the mismatched disturbances from the state variables of the reconstructed system.