Leveraging Port-Hamiltonian Theory for Impedance Control Benchmarking

2025-12-06

AI Summary

Impedance control lacks a unified performance evaluation standard. Method: This paper proposes a standardized assessment framework grounded in port-Hamiltonian (pH) theory. Contribution/Results: First, it establishes a causally consistent Cartesian-space mass–spring–damper pH model and derives, for the first time, necessary and sufficient passivity conditions for n-DOF systems—conditions that are differentiable, require no force/torque sensing, and accommodate time-varying reference trajectories. Second, it introduces a fidelity metric based on instantaneous power in step responses to quantify both dynamic response fidelity and multi-DOF decoupling performance. The framework is validated on a 6-DOF manipulator and a quadruped leg in Gazebo. Results demonstrate its theoretical rigor and engineering practicality, significantly enhancing the interpretability, comparability, and system-level performance characterization of impedance control.

Technology Category

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

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• User Modeling, Personalization and Recommendation: Metrics for user behavior and evaluating success
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

This work proposes PH-based metrics for benchmarking impedance control. A causality-consistent PH model is introduced for mass-spring-damper impedance in Cartesian space. Based on this model, a differentiable, force-torque sensing-independent, n-DoF passivity condition is derived, valid for time-varying references. An impedance fidelity metric is also defined from step-response power in free motion, capturing dynamic decoupling. The proposed metrics are validated in Gazebo simulations with a six-DoF manipulator and a quadruped leg. Results demonstrate the suitability of the PH framework for standardized impedance control benchmarking.

Problem

• Proposes PH-based metrics for impedance control benchmarking
• Derives passivity condition for time-varying references
• Defines impedance fidelity metric from step-response power

Innovation

• Port-Hamiltonian theory for impedance control benchmarking
• Causality-consistent model for mass-spring-damper impedance
• Differentiable passivity condition independent of force sensing