“…[8][9][10] In such type, the significant represent is quadrotor that has four symmetric rotorcrafts in each couple. 8,9,11 The proportional-integral-derivative (PID) controllers 3,8,9,[12][13][14][15] are of low cost, uncomplicated structure, and easy design, which are applied to many hi-tech fields, from industrial machine to biped robot, and especially in UAV systems. However, the controller methods such as PID, backstepping, and fuzzy PID approaches for the UAVs 10,11,16 have problems in practical applications for better performance, robustness, and less oscillation.…”