Adaptive control of a UAV with continuously time varying center of gravity

In this paper we apply the concept of adaptive control to an Unmanned Aerial Vehicle (UAV) with time varying center of gravity (CG). Continuous change of payload mass and CG's location happens in several real-world applications, e.g., transportation of a package which has moving parts in it or a UAV spraying disinfectant or pesticide. Control of UAVs with varying CG location is challenging since the changed dynamics require adaptation in controller parameters for stable and effective flight. The research carried out in literature have focused on solution for an offset (but fixed) CG or for CG varying at certain time instants. However, for scenarios in which the CG continuously varies with time, existing schemes are ineffective. We first derive the dynamics of the entire system with time varying CG. Following this, the proposed feedback linearization and adaptive control strategies are presented. Extensive results from numerical simulation for trajectory tracking and waypoint navigation are provided for constant CG versus time varying CG cases. The results demonstrate the effectiveness of the proposed work over existing work on constant CG case. Copyright (c) 2022 The Authors. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0)