Robust nonlinear observer design for twin rotor control system

This paper presents a robust nonlinear observer for twin rotor control system (TRCS). The TRCS is a class of nonlinear uncertain system having unstable and coupled dynamics. The dynamics of TRCS are similar to a helicopter in certain aspects. Due to high coupling effect, the controller design of TRCS is challenging as well as interesting. The proposed robust observer is designed using sliding mode approach. Coulomb friction is introduced in the TRCS to demonstrate the robustness of the proposed observer. Finally simulation results highlight the performance of the proposed observer to compensate the nonlinear friction term in the system.