Abstract: In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

Abstract: An actuator module for inducing the relative motion of robot members joined in a robot joint includes a Ferguson epicyclic gear train, integral motor and integrated control means. The gear train comprises a plurality of base gears connected to the robot members and a plurality of planet gear carriers, each planet gear carrier having a plurality of planet gears rotatably mounted therein. A motor integrated with certain gear train components induces the rotation of the planet gear carriers about or within the base gears. Because of the Ferguson paradox, this induces the motion of base gears connected to one robot member relative to those connected to the other robot member, which in turn causes the relative motion of the robot members. The actuator module can be configured as dual substantially symmetric systems and may comprise multiple stages of epicyclic gearing.

Abstract: A remote manipulator for a robotic system has a plurality of intercoupled manipulator links and a principal manipulator drive unit coupled to manipulate the remote position of an end-effector supported by said links in response to a manipulator control signal. Coarse adjustment of the end effector is refined by a precision control subsystem which augments the principal manipulator to achieve a "control-in-the-small" robotic manipulator system. The augmenting precision-achieving subsystem includes a coupling mechanism, coupled with one of the links, for establishing the position of one of the links relative to another link, and a precision adjustment device, associated with the coupling mechanisms for adjusting the position of the one link relative to another link as established by the coupling mechanism, independently of the action of the principal manipulator drive unit and effectively without bearing the load supported by the one of said links.