Polytopic Attitude Control System for Nonlinear Unmanned Rotorcraft

Attitude control of unmanned rotorcrafts (UR) is most critical phase of flight control system design since it has main role in system stability and maneuverability. This paper presents a novel attitude control scheme for an UR. In this research, a polytypic linear parameter varying (PLPV) model of unmanned helicopter is derived based on its nonlinear dynamic model and a set of linear matrix inequalities is defined to design the attitude control system. The PLPV model is generated by linearization of the nonlinear dynamic model around several trim points. The proposed control system design is evaluated by applying generated control inputs in perturbing and non-perturbing environment condition and also affected by uncertainty. The stability performance of the system has been analyzed in different modes and positions. The results clearly show that the PLPV control system can maintain complete stability of unmanned helicopter in different scenarios.