Full state backstepping control of quadrotor using sliding mode observer

This paper is concerned about backstepping control by running parallel sliding mode observer for a quadrotor Unmanned Ariel Vehicle. This sliding mode observer is filtered by a low pass filter to improve the performance of the observer. By filtering sliding mode outputs side effect caused by discontinuity of the sign function of observer is compensated and smooth results achieved. This observer will estimate the disturbances and observe the velocities (𝑥̇,𝑦̇,𝑧̇,𝜙̇,𝜃̇,𝜓̇) of the quadrotor. The controller is intended to reach desired position (𝑥,𝑦,𝑧) and yaw angle (𝜓) while tilt angles (𝜙,𝜃) remains stable and velocities are affected by bounded external disturbances; however, whole system is stable. In addition to verifying efficiency of the method simulation results show the good performances of tracking and robustness of the studied observer-controller.