A New Robust Adaptive-Fuzzy Control Method Applied to Quadrotor Helicopter Stabilization

A new method for adaptive-fuzzy control achieves stabilization of a quadrotor helicopter in the presence of sinusoidal wind disturbance. Techniques traditionally used in adaptive control for robust parameter updates may not be sufficient for fuzzy schemes. In particular, e-modification may result in the fuzzy-membership centers drifting to large values when persistent oscillations are present in the input. These large values can cause control signal chatter, which can be undesirable or even cause instability if they excite unmodeled dynamics. A new method for robust updates is proposed that prevents this drift in the fuzzy membership centers. In the new method, a set of alternate membership function centers guides the adaptation process in order to prevent drift. A Lyapunov-stability proof ensures the uniform ultimate boundedness of all signals. A simulation of a quadrotor helicopter demonstrates the high performance and robust stability of the new method