Experimental Flight Testing of an Adaptive Autopilot with Parameter Drift Mitigation

TL;DR

This paper presents a modified adaptive autopilot for multicopters that mitigates parameter drift and enhances robustness through a static nonlinearity and retrospective cost adaptive control, validated by simulation and real-world tests.

Contribution

It introduces a novel modification to adaptive autopilots using static nonlinearity and retrospective cost adaptive control to prevent parameter drift and improve stability.

Findings

The modified autopilot reduces parameter drift in simulations.

Experimental tests confirm improved robustness and stability.

The approach outperforms traditional adaptive controllers in maintaining control accuracy.

Abstract

This paper modifies an adaptive multicopter autopilot to mitigate instabilities caused by adaptive parameter drift and presents simulation and experimental results to validate the modified autopilot. The modified adaptive controller is obtained by including a static nonlinearity in the adaptive loop, updated by the retrospective cost adaptive control algorithm. It is shown in simulation and physical test experiments that the adaptive autopilot with proposed modifications can continually improve the fixed-gain autopilot as well as prevent the drift of the adaptive parameters, thus improving the robustness of the adaptive autopilot.