Sliding Mode Path following and Control Allocation of a Tilt-Rotor Quadcopter

Abstract

A tilt-rotor quadcopter (TRQ) equipped with four tilt-rotors is more agile than its under-actuated counterpart and can fly at any path while maintaining the desired attitude. To take advantage of this additional control capability and enhance the quadrotor system’s robustness and capability, we designed two sliding mode controls (SMCs): the typical SMC exploits the properties of the rotational dynamics, and the modified SMC avoids undesired chattering. Our simulation studies show that the proposed SMC scheme can follow the planned flight path and keep the desired attitude in the presence of variable deviations and external perturbations. We demonstrate from the Lyapunov stability theorem that the proposed control scheme can guarantee the asymptotic stability of the TRQ in terms of position and attitude following via control allocation.