Abstract: A modular robotic snake-arm assembly is described which is animated principally by an articulated drive shaft that threads the length of the snake-arm. The articulated drive shaft is driven by a motor in the fixed base. One or more clutch mechanisms in each segment couple with the articulated drive shaft so as to cause all snake arms further from the base to reorient in either one or two angles, in either direction. Snake-arm segments can be coupled end-to-end to form a robotic snake arm of great length.

Abstract: A modular robotic snake-arm assembly is described which is animated principally by an articulated drive shaft that threads the length of the snake-arm. The articulated drive shaft is driven by a motor in the fixed base. One or more clutch mechanisms in each segment couple with the articulated drive shaft so as to cause all snake arms further from the base to reorient in either one or two angles, in either direction. Snake-arm segments can be coupled end-to-end to form a robotic snake arm of great length.

Abstract: A system is disclosed that determines a spatial position of a tracker device relative to an object sending a return signal to the tracker. Such a system advantageously maintains phase accuracy between a forward signal from the tracker device and the return signal from the object. The system can include, as part of a tracker device, a reference signal generator, a transmitter, a receiver, and a spatial position computer. The reference signal generator is responsive to and phase-stabilized by a broadcast signal, e.g., a signal received from a commercial AM broadcast transmitter. The transmitter and receiver are both coupled to and phase-stabilized by the tracker reference signal generator. Variations and methods with different advantageous features are also described.