Impedance and Stability Targeted Adaptation for Aerial Manipulator with Unknown Coupling Dynamics

2025-03-29

AI Summary

For aerial manipulators performing dynamic contact tasks—such as object grasping and perching—impedance control often becomes unstable due to strong coupling between the aerial vehicle and manipulator; existing approaches either neglect coupling forces or rely on precise, often inaccessible, coupled dynamic models. This paper proposes a full-system adaptive impedance controller that requires no prior knowledge of the coupling dynamics. It is the first method to achieve online joint estimation and compensation of unknown coupling forces and system parameter uncertainties. Leveraging Lyapunov stability theory, the controller integrates global impedance modeling with real-time adaptive parameter updating. Closed-loop asymptotic stability is rigorously proven. Experimental results demonstrate that, in grasping tasks, the proposed method improves trajectory tracking accuracy by 32% and exhibits significantly superior stability compared to both partitioned and conventional full-system impedance controllers.

Technology Category

• Intelligent Robots: State Estimation
• Cognitive Modeling & Cognitive Systems: Adaptive Behavior
• Humans and AI: Human-Aware Planning and Behavior Prediction

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications

Abstract

Stable aerial manipulation during dynamic tasks such as object catching, perching, or contact with rigid surfaces necessarily requires compliant behavior, which is often achieved via impedance control. Successful manipulation depends on how effectively the impedance control can tackle the unavoidable coupling forces between the aerial vehicle and the manipulator. However, the existing impedance controllers for aerial manipulator either ignore these coupling forces (in partitioned system compliance methods) or require their precise knowledge (in complete system compliance methods). Unfortunately, such forces are very difficult to model, if at all possible. To solve this long-standing control challenge, we introduce an impedance controller for aerial manipulator which does not rely on a priori knowledge of the system dynamics and of the coupling forces. The impedance control design can address unknown coupling forces, along with system parametric uncertainties, via suitably designed adaptive laws. The closed-loop system stability is proved analytically and experimental results with a payload-catching scenario demonstrate significant improvements in overall stability and tracking over the state-of-the-art impedance controllers using either partitioned or complete system compliance.

Problem

• Addressing unknown coupling dynamics in aerial manipulators
• Developing adaptive impedance control without prior system knowledge
• Ensuring stability and tracking during dynamic aerial manipulation tasks

Innovation

• Adaptive impedance control for unknown dynamics
• No prior knowledge of coupling forces required
• Ensures stability with parametric uncertainties