Attitude control of quad-rotor UAVs using an intuitive kinematics model

This paper presents the work on attitude control of quad-rotor UAVs applying an intuitive kinematics representation, called rotation vector. There are three elements in the rotation vector which has clear physical meaning of the rotations and avoids the singularity problem of Euler angles and the unity norm constraint problem of quaternions. Basic definition of the rotation vector and its relation with the object body angle velocity is introduced and used in the 6DOF quadrotor dynamics. Based on the property that the rotation vector rate is equivalent to the body angle velocity when the rotation is small, a simple and intuitive attitude reference is proposed. A proportional-derivative (PD) law is used by integrating the new attitude reference for the attitude control of quad-rotor UAVs. Simulation results prove the efficiency of the new method which provides a new model with intuitive physical meaning for quadrotor UAVs.