Control

Zero-Torque Mode

Zero-torque mode is an operating mode in which a robot's actuators are commanded to exert no torque beyond, in most implementations, compensation for gravity and friction, so a person can move the arm freely by hand. It is the basis of kinesthetic teaching, where demonstrations are recorded by physically guiding the robot, and requires torque-controlled or backdrivable joints to feel genuinely transparent.

Why it matters for physical AI

Hand-guiding is one of the most natural demonstration interfaces for manipulation data collection, and the quality of a robot's zero-torque behavior directly shapes how smooth and human-like the recorded trajectories are.