Passivity-Based Control

Passivity-based control studies how to use energy storage, supply, and dissipation to keep interacting dynamical systems stable, even when models or environments are uncertain. Common approaches include port-Hamiltonian modeling and energy shaping, impedance and admittance control, energy tanks and passivity filters, and wave-based methods for delayed teleoperation. These methods are used in contact-rich robotics, haptics, exoskeletons, and human-robot interaction, with growing work that builds passivity guarantees into learned models and reinforcement-learning controllers. A central tension is preserving stability under contact, delay, or learned dynamics while avoiding overly conservative behavior that limits tracking, transparency, or energy efficiency.