Autonomous Aerial Non-Destructive Testing: Ultrasound Inspection with a Commercial Quadrotor in an Unstructured Environment

TL;DR

This paper demonstrates a fully autonomous ultrasound-based non-destructive testing system using a commercial quadrotor, showcasing real-time control and software integration in unstructured environments.

Contribution

It introduces a novel integrated control architecture enabling off-the-shelf multirotors to perform autonomous contact-based NDT inspections.

Findings

Successful autonomous ultrasound inspections in unstructured environments.

Real-time multi-rate control scheme validated on a commercial quadrotor.

Retrofitting off-the-shelf drones for autonomous physical interaction.

Abstract

This work presents an integrated control and software architecture that enables arguably the first fully autonomous, contact-based non-destructive testing (NDT) using a commercial multirotor originally restricted to remotely-piloted operations. To allow autonomous operation with an off-the-shelf platform, we developed a real-time framework that interfaces directly with its onboard sensor suite. The architecture features a multi-rate control scheme: low-level control is executed at 200 Hz, force estimation at 100 Hz, while an admittance filter and trajectory planner operate at 50 Hz, ultimately supplying acceleration and yaw rate commands to the internal flight controller. We validate the system through physical experiments on a Flyability Elios 3 quadrotor equipped with an ultrasound payload. Relying exclusively on onboard sensing, the vehicle successfully performs autonomous NDT measurements within an unstructured, industrial-like environment. This work demonstrates the viability of retrofitting off-the-shelf platforms for autonomous physical interaction, paving the way for safe, contact-based inspection of hazardous and confined infrastructure.