Hybrid Impedance-Admittance Control with Multi-Link Aerial Robot for Contact-Rich Surface Sliding Task

2026-08-03

AI Summary

This work addresses the challenge of simultaneously achieving disturbance rejection and compliance with unknown curved surfaces in sliding contact tasks for multi-link aerial robots. To this end, a hybrid impedance–admittance control strategy is proposed, which enables coordinated control through functional decoupling between joints and propellers: the joints implement admittance control to conform to unknown contact geometries, while the propellers execute impedance control to ensure motion stability. This approach represents the first implementation on a single aerial robotic platform that overcomes the longstanding limitation of incompatibility between impedance and admittance control due to their opposing force–motion causality when sharing actuators. Experimental results demonstrate that the proposed architecture significantly enhances both robustness and compliance during sliding manipulation on unknown surfaces.

Abstract

Multi-link aerial robots can actively deform their articulated structures during flight, giving them strong potential for aerial manipulation. However, they still face substantial challenges in contact-rich aerial manipulation tasks such as surface sliding, which requires both disturbance robustness and compliance to uncertain surface geometry. Force-control strategies such as impedance and admittance control are commonly employed to address these requirements. Although impedance control can provide disturbance-resistant interaction and admittance control can offer compliant adaptation, their opposite force--motion causalities prevent their simultaneous implementation when applied through the same actuation source, such as the rotor thrusts used by conventional aerial robots. To overcome this limitation, we propose a hybrid impedance--admittance control strategy for a multi-link aerial robot. The articulated morphology enables a functional separation of force and motion regulation across joint and rotor actuation sources. In this framework, admittance behavior is generated through joint angle regulation to enhance adaptive interaction, while impedance behavior is achieved by modulating rotor thrust to regulate the sliding motion. This structural coordination allows the robot to leverage the complementary strengths of both control paradigms. As a result, the multi-link aerial robot achieves resilient and adaptive surface sliding. Experimental results demonstrate robust and compliant sliding performance on unknown surfaces.

Problem

• multi-link aerial robot
• surface sliding
• contact-rich manipulation
• impedance control
• admittance control

Innovation

• hybrid impedance-admittance control
• multi-link aerial robot
• contact-rich manipulation
• surface sliding
• articulated morphology