A Comparative Study of INDI and NDI with Nonlinear Disturbance Observer for Aerial Robotics

TL;DR

This paper compares the robustness of INDI and NDI+NDO control strategies for aerial robots through extensive simulations, highlighting their respective strengths and weaknesses under various conditions.

Contribution

It provides a systematic simulation-based comparison of INDI and NDI+NDO, offering practical insights into their robustness and performance in aerial robotics.

Findings

INDI shows stronger robustness under model mismatch and stress.

NDI+NDO matches nominal performance but is more sensitive to non-ideal conditions.

Results guide the choice of control strategies for aerial robots.

Abstract

This work presents a simulation-based comparative robustness analysis of Incremental Nonlinear Dynamic Inversion (INDI) and Nonlinear Dynamic Inversion augmented with a nonlinear disturbance observer (NDI+NDO) for fully actuated aerial robots. A systematic simulation campaign across representative operating scenarios is conducted, where we compare tracking performance, robustness, control effort, under parametric variations, external disturbances, and measurement noise. Results show that INDI demonstrates stronger robustness in several model-mismatch and combined-stress cases, while NDI+NDO primarily matches nominal performance but exhibits greater sensitivity under several non-ideal conditions. These findings provide practical guidance on the relative strengths and limitations of incremental and observer-based inversion strategies for aerial robotic applications.