Constrained Imitation Learning for a Flapping Wing Unmanned Aerial Vehicle

TL;DR

This paper develops a constrained imitation learning approach to control a flapping wing UAV, improving stability and computational efficiency by avoiding online trajectory generation and handling nonlinear coupled dynamics.

Contribution

It introduces a novel constrained imitation learning framework that stabilizes nonlinear coupled dynamics of flapping wing UAVs without online trajectory computation.

Findings

Enhanced stability of the control system.

Reduced computational complexity.

First nonlinear control for coupled dynamics without linearization.

Abstract

This paper presents a data-driven optimal control policy for a micro flapping wing unmanned aerial vehicle. First, a set of optimal trajectories are computed off-line based on a geometric formulation of dynamics that captures the nonlinear coupling between the large angle flapping motion and the quasi-steady aerodynamics. Then, it is transformed into a feedback control system according to the framework of imitation learning. In particular, an additional constraint is incorporated through the learning process to enhance the stability properties of the resulting controlled dynamics. Compared with conventional methods, the proposed constrained imitation learning eliminates the need to generate additional optimal trajectories on-line, without sacrificing stability. As such, the computational efficiency is substantially improved. Furthermore, this establishes the first nonlinear control system that stabilizes the coupled longitudinal and lateral dynamics of flapping wing aerial vehicle without relying on averaging or linearization. These are illustrated by numerical examples for a simulated model inspired by Monarch butterflies.