Joint drive development for the Space Station Remote Manipulator System

Parts of the design of the Space Station Remote Manipulator System's joint drive (the motor and drive electronics) have reached the proof of concept phase, while other parts (the joint drive module, joint housing, and joint electronic unit packaging) exist at present only as mockups of design concepts. The system requirements for the joint drive are outlined and the drive system architectures are described. Drive electromechanics are located within each joint and drive electronics are physically distributed over the length of the manipulator arm. The drives system has a modular design for ready maintainability in orbit. Equipment features are also described along with the considerations that led to their incorporation. These include the brushless motors, friction disc brakes, compound differential planetary gear train, and resolver based position and velocity sensing devices.