Observer-Based Sliding Mode Control of a 6-DOF Quadrotor UAV

A sliding mode control (SMC) strategy is presented for a 6 degrees of freedom (DOF) quadrotor unmanned aerial vehicle (UAV), which achieves asymptotic position and attitude regulation. To overcome the practical limitations of velocity measurements, a sliding mode observer (SMO) is designed to estimate both the translational and rotational velocities. A rigorous Lyapunov-based analysis is provided to prove convergence to a desired set point in the presence of model uncertainties. Computer simulation results are presented, which demonstrate the effectiveness of the control law when applied to the complete nonlinear system dynamics.