Leveraging Port-Hamiltonian Theory for Impedance Control Benchmarking

TL;DR

This paper introduces port-Hamiltonian based metrics for benchmarking impedance control, providing a causality-consistent model and passivity conditions that are validated through simulations, enhancing standardization in the field.

Contribution

It presents a novel port-Hamiltonian framework for impedance control benchmarking, including new metrics and passivity conditions applicable to complex robotic systems.

Findings

Metrics validated in Gazebo simulations with a six-DoF manipulator.

Port-Hamiltonian framework effectively standardizes impedance control benchmarking.

Proposed methods are force-torque sensing-independent and handle time-varying references.

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.