A subcategory covering joint actuators — integrated drive units combining a motor, gearbox, encoder, and control electronics in a single module, used in the joints of robot limbs and torsos.

A PMSM (Permanent Magnet Synchronous Motor) joint actuator is an integrated drive module that uses a permanent magnet synchronous motor to provide precise position, velocity, and torque control at robot joints. It offers high power density, low losses, and deterministic torque response, making it a popular choice in robotic manipulators, exoskeletons, and humanoid robots. The unit typically integrates an encoder, gearbox, and motor controller into a single compact assembly.