US Patent 7296486 Hydraulic motor drive sensor adapter

Angular movement detectors may be disposed within or proximate to joints in one or more members of articulated arms and linked via one or more communications networks to a controller to provide angular movement data to the controller for use in controlling movement of the articulated arm. The communications networks may be redundant. In an embodiment, the angular movement detector comprises a hydraulic motor drive sensor adapter which uses an eccentrically rotating main shaft to rotate a drive shaft to which the main shaft is loosely connected to further rotate a socket housing about a constant central axis. A trigger mounted in the socket housing generates a detectable field.