Robust Tracking Control of a Quad-Rotor Helicopter Utilizing Sliding Mode Control with a Nonlinear Sliding Surface

Abstract

This paper presents a sliding mode control using a nonlinear sliding surface (NSS) to design a robust tracking controller for a quad-rotor helicopter. An NSS is designed to provide a variable damping ratio for the closed-loop dynamics of the system to achieve a quick response and low overshoot performance. The dynamics of the quad-rotor helicopter is derived by the Newton-Euler formulation for a rigid body. The global stability of the proposed control strategy is guaranteed on the basis of the Lyapunov stability theory. The robustness and effectiveness of the proposed control system are demonstrated experimentally, providing comparative results with a conventional linear sliding surface. The NSS provides robust tracking control under significant wind gusts.