# Attitude Tracking Control for Aerobatic Helicopters: A Geometric Approach

## TL;DR

This paper develops a geometric control method for small aerobatic helicopters, effectively handling rotor-fuselage coupling to achieve precise attitude tracking with proven stability and experimental validation.

## Contribution

Introduces a novel geometric and backstepping control approach for coupled rotor-fuselage dynamics in small helicopters, ensuring global stability on SO(3).

## Key findings

- Controller achieves aggressive roll attitude tracking.
- Validated through simulation and real-world experiments.
- Ensures local exponential stability of the system.

## Abstract

We consider the problem of attitude tracking for small-scale aerobatic helicopters. A small scale helicopter has two subsystems: the fuselage, modeled as a rigid body; and the rotor, modeled as a first order system. Due to the coupling between rotor and fuselage, the complete system does not inherit the structure of a simple mechanical system. The coupled rotor fuselage dynamics is first transformed to rigid body attitude tracking problem with a first order actuator dynamics. The proposed controller is developed using geometric and backstepping control technique. The controller is globally defined on $SO(3)$ and is shown to be locally exponentially stable. The controller is validated in simulation and experiment for a 10 kg class small scale flybarless helicopter by demonstrating aggressive roll attitude tracking.