Amir Farhad Ehyaei - Assistant Professor in the Department of Electrical Engineering at Imam Khomeini International University, f.ehyaei@eng.ikiu.ac.ir, Qazvin,Iran
Kiarash Aryankia - Graduated M.Sc. student from Electrical Engineering Department at Sharif University of Technology, aryankia@alum.sharif.edu, Tehran, Iran

This paper is mainly 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. Forasmuch as filtering sliding mode outputs eliminates stimulated discontinuity of the sign function of observer, smooth results achieved. This observer will estimate the disturbances and observe the velocities (

Backstepping control, Sliding mode observer, Quadrotor, Unmanned Ariel Vehicle