Design and Control of Direct-Drive Arms

Electromechanial robots employ gearing mechanisms to match the impedances of drives and their corresponding loads. These mechanisms, while used extensively, degrade control performance of the robots. Direct-Drive, on the other hand, is a method in which a actuator is coupled directly to its load without gearing. This innovative design approach has shown great improvement in control performances. Its unique features meet the critcal requirements of many advanced robot applications. In this paper, the state-of-the-art of direct-drive arms is presented. Progress in arm design, motors and sensors, as well as control system design are presented. Then, the design and control of the M.I.T direct-drive arm are discussed in detail.