Control

Contact Force Estimation

Contact force estimation is the inference of external forces and torques acting on a robot, either from dedicated force-torque sensors or indirectly from joint torque measurements, motor currents, and dynamic models via momentum-observer or disturbance-observer techniques. Sensorless estimation enables collision detection and force control on arms without wrist sensors, though accuracy is limited by model quality and friction. Learned estimators increasingly fuse proprioception, currents, and vision.

Why it matters for physical AI

Force awareness without expensive sensing on every joint enables safe contact detection and force-conditioned policies at fleet scale, and estimated wrenches are valuable labels for training contact-rich skills.