Impedancedriven

Impedancedriven is a control paradigm used in robotics, biomechanics, and haptics in which the interaction with the environment is governed by a programmed mechanical impedance rather than fixed position or force targets. The goal is to achieve compliant, safe, and robust contact with objects or users. It is closely related to impedance control and is often used interchangeably with that term in practice.

The controller defines a target impedance, described by virtual mass, damping, and stiffness, and the system adjusts motion in response to forces to approximate that impedance. Sensors measure contact forces and motion, and the controller modulates velocity or position to maintain the desired dynamic relationship, typically via feedback loops and virtual models.

Impedancedriven control contrasts with pure position control, which fixes trajectories, and with pure force control, which specifies forces. The impedance perspective emphasizes dynamic coupling between force and motion. Admittance control is a related scheme in which measured forces determine motion; together they form a family of impedance-based interaction strategies.

Applications include robotic manipulation with safe contact, rehabilitation devices, prosthetics, teleoperation, and surgical robotics. The concept derives from impedance control introduced in the 1980s by Hogan and colleagues and has evolved with advances in sensing and computation. Practical challenges include choosing appropriate impedance parameters, stability under delays, and robustness to modeling errors.