Robust tracking of an unknown trajectory with a multi-rotor UAV: A high-gain observer approach

TL;DR

This paper presents a high-gain observer-based control method for multi-rotor UAVs to robustly track unknown trajectories despite modeling errors and disturbances, validated through numerical simulations.

Contribution

It introduces an extended high-gain observer framework combined with output feedback control for unknown trajectory tracking in multi-rotors, with rigorous stability analysis.

Findings

Successful estimation of trajectory, states, and disturbances using EHGO.

Stable tracking performance demonstrated in numerical simulations.

Effective handling of modeling errors and external disturbances.

Abstract

We study a trajectory tracking problem for a multi-rotor in the presence of modeling error and external disturbances. The desired trajectory is unknown and generated from a reference system with unknown or partially known dynamics. We assume that only position and orientation measurements for the multi-rotor and position measurements for the reference system can be accessed. We adopt an extended high-gain observer (EHGO) estimation framework to estimate the feed-forward term required for trajectory tracking, the multi-rotor states, as well as modeling error and external disturbances. We design an output feedback controller for trajectory tracking that comprises a feedback linearizing controller and the EHGO. We rigorously analyze the proposed controller and establish its stability properties. Finally, we numerically illustrate our theoretical results using the example of a multi-rotor landing on a ground vehicle.