Fast control allocation algorithm for tilt-rotor VTOL aircraft

TL;DR

This paper presents a novel control allocation algorithm for tilt-rotor VTOL aircraft that manages complex propeller-wing interactions using Groebner basis algorithms, enabling linear control laws despite non-linear dynamics.

Contribution

It introduces a control allocation method that masks non-linearity in tilt-rotor dynamics, allowing simpler linear control strategies to be used effectively.

Findings

High accuracy in modeling propeller-wing interactions.

Effective linear control law implementation for tilt-rotor aircraft.

Quantified performance improvements over existing methods.

Abstract

Control algorithms initially developed for tilt-wing vertical take-off and landing (VTOL) aircraft are adapted to the tilt-rotor design. The main difference between the two types of planes is the more complicated interaction between propellers and wings in the tilt-rotor design. Unlike tilt-wing design, the tilt-rotor case varies the angle between the propeller disk and wing cord line, thus introducing a non-linear dependency of lift on thrust and tilt angle. In this paper we develop a precise control allocation method, utilizing Groebner basis algorithms to mask the non-linearity of the control action and allow the use of linear time-invariant control laws for attitude and velocity control architectures. The performance of our approach is discussed and quantified w.r.t. the accuracy of the developed propeller-wing interaction model.