Semi-autonomous Teleoperation using Differential Flatness of a Crane Robot for Aircraft In-Wing Inspection

TL;DR

This paper introduces a differential flatness-based control method for a crane robot used in aircraft wing inspections, significantly reducing oscillations and collisions during teleoperation, thereby enhancing safety and efficiency.

Contribution

It presents a novel application of differential flatness to design collision-free, low-oscillation trajectories for crane robots in confined space inspections, improving teleoperation performance.

Findings

Oscillations reduced by 89%

Collisions eliminated from 33% to 0%

Task efficiency improved by 18.7%

Abstract

Visual inspection of confined spaces such as aircraft wings is ergonomically challenging for human mechanics. This work presents a novel crane robot that can travel the entire span of the aircraft wing, enabling mechanics to perform inspection from outside of the confined space. However, teleoperation of the crane robot can still be a challenge due to the need to avoid obstacles in the workspace and potential oscillations of the camera payload. The main contribution of this work is to exploit the differential flatness of the crane-robot dynamics for designing reduced-oscillation, collision-free time trajectories of the camera payload for use in teleoperation. Autonomous experiments verify the efficacy of removing undesired oscillations by 89%. Furthermore, teleoperation experiments demonstrate that the controller eliminated collisions (from 33% to 0%) when 12 participants performed an inspection task with the use of proposed trajectory selection when compared to the case without it. Moreover, even discounting the failures due to collisions, the proposed approach improved task efficiency by 18.7% when compared to the case without it.