Stabilizing Quadrotor Helicopter Based on Controlled Lagrangians

Abstract

A stabilization controller for the quadrotor helicopter is designed based on controlled Lagrangians method in this paper. Firstly, the dynamical model of quadrotor helicopter is simplified by input transformations. With linearization at the desired equilibrium and invertible state transformations, the model can be divided to four subsystems. Then controlled Lagrangians method is applied to stabilize the two subsystems with one under-actuation degree, and the other two subsystem are stabilized by PD control laws. Finally, local asymptotic stability of the closed-loop system is proved theoretically and verified by simulation results. Different from common-used controllers, the controller presented in this paper does not depend on the outer/inner loop structure and the time-scale separate principle, which always hinder rigorous stability analysis of the controlled system and complicate control algorithm.