Robust Sliding Mode and Admittance Control of Underactuated Aerial Manipulators for Contact-Based Inspection

2026-08-11

AI Summary

This study addresses the challenge of stable interaction in contact-based industrial inspection using underactuated aerial manipulators, where dynamic coupling between vehicle attitude and force generation compromises performance. To overcome this, the authors propose a robust control framework that integrates integral-augmented sliding mode control with admittance control. A key innovation lies in mapping the measured contact force into a feedforward attitude compensation term, while actively leveraging the single-degree-of-freedom manipulator to adjust the vehicle’s tilt and maintain consistent surface contact—effectively decoupling motion from force interaction. Experimental results demonstrate that the proposed method achieves a root-mean-square error of 0.12 N in contact force regulation, reliably sustains interaction forces up to 20 N, and significantly outperforms conventional PID control in both trajectory tracking accuracy and disturbance rejection.

Abstract

Contact-based industrial inspection requires aerial platforms to maintain stable interaction while rejecting disturbances. Underactuated aerial manipulators present control challenges due to the dynamic coupling between vehicle attitude and force generation. This paper proposes a robust control framework for an underactuated hexarotor equipped with a 1-DoF manipulator to perform sustained contact inspection. The architecture integrates integral-augmented Sliding Mode Control (SMC) for trajectory tracking with an admittance control law for force regulation. The contact force is mapped to a feedforward attitude term, while the 1-DoF arm actively compensates for the tilt to maintain surface alignment. Software-in-the-loop simulations demonstrate that the SMC-based approach achieves superior tracking and coupling rejection compared to traditional PID. Furthermore, the interaction strategy achieved precise force regulation with an RMSE of 0.12N and was able to stably exert up to 20N force, confirming the system's efficacy for stable, reliable contact-based inspection.

Problem

• underactuated aerial manipulators
• contact-based inspection
• dynamic coupling
• force regulation
• disturbance rejection

Innovation

• Sliding Mode Control
• Admittance Control
• Underactuated Aerial Manipulator
• Contact-Based Inspection
• Dynamic Coupling Rejection