Globally Defined Dynamic Modelling and Geometric Tracking Controller Design for Aerial Manipulator

This study presents a globally defined dynamics for a conventional multirotor equipped with a single n-DOF manipulator using modified Lagrangian dynamics. This enables the reformulation of entire dynamics directly on SO(3) without exploiting any local coordinates, and thus problems such as the singularity of Euler angles can be avoided. Since skew- symmetric property of Coriolis matrix C and inertia matrix facilitates stability analysis, we propose a method to compute C which guarantees the skew-symmetric property by considering C as a summation of two sub-matrices. Then, a geometric tracking controller is designed based on decoupled dynam- ics applying passive decomposition. The proposed controller guarantees almost global region of attraction. We validate our method via consecutive aerial flipping experiments.