An Adaptive Block Backstepping Controller for Attitude Stabilization of a Quadrotor Helicopter

-A new block backstepping controller is proposed to solve the attitude stabilization problem for a quadrotor helicopter. The attitude kinematical model is obtained and translated into a MIMO nonlinear system with generalized uncertainties. Under the consideration of the coupling between the attitude angles, a nominal block backstepping controller is designed. The obtained controller is then augmented by a robust adaptive function to approximate the modeling errors and external disturbance. A nonlinear tracking-differentiator is applied to reduce computer explosion which is a ubiquitous problem in backstepping controllers. The closedloop system is proved to be stable and exponential convergent through constructing appropriate Lyapunov function. Simulation results in the presence of external momentary disturbances and parametric uncertainties are presented to corroborate the effectiveness and the robustness of the proposed strategy. Key-Words: Quadrotor; Block Backstepping; Robust function; Adaptive control; tracking-differentiator