Control

Joint Torque

Joint torque is the rotational effort exerted at a robot joint, produced by the actuator and transmission and balanced against gravity, inertia, friction, and external contact forces. It can be estimated from motor current or measured directly with strain-gauge sensors or series elastic elements, and torque-level control interfaces enable impedance control, gravity compensation, and sensitive collision detection.

Why it matters for physical AI

Access to accurate joint torque is what separates robots that can feel and comply from those that only track positions, underpinning contact-rich skills and safe physical interaction with people.