Flatness-based nonlinear control strategies for trajectory tracking of quadcopter systems

TL;DR

This paper introduces flatness-based nonlinear control methods for quadcopters, enabling precise trajectory tracking through flat output parametrization and B-spline optimization, with comparative analysis of control strategies.

Contribution

It provides a novel flat output for quadcopters and leverages B-splines for optimal trajectory generation, enhancing control accuracy and flexibility.

Findings

Flat output enables full state and input parametrization.

B-splines facilitate optimal trajectory planning with way-point constraints.

Control strategies show improved tracking performance in simulations.

Abstract

This paper proposes several nonlinear control strategies for trajectory tracking of a quadcopter system based on the property of differential flatness. Its originality is twofold. Firstly, it provides a flat output for the quadcopter dynamics capable of creating full flat parametrization of the states and inputs. Moreover, B-splines characterizations of the flat output and their properties allow for optimal trajectory generation subject to way-point constraints. Secondly, several control strategies based on computed torque control and feedback linearization are presented and compared. The advantages of flatness within each control strategy are analyzed and detailed through extensive simulation results.