Optical commutation and tilt sensing for a permanent magnet gyro

A permanent magnet two degree of freedom gyroscope (10) utilizing a single rotor (12) having a trapezoidal shaped pattern formed thereon. The trapezoidal pattern consists of a reflective segment (11) and a non reflective segment (13). Two optical sensors (14, 18) fixed with respect to the stator, obtain angular displacement information about the two axes perpendicular to the spin axis, rotor pole location information, which is used for commutation, and, rotor speed information. The present invention deals with an apparatus and method for starting, running and torquing the two degree of freedom permanent magnet gyro motor (10) based on position and displacement information obtained from the two optical detectors (14, 18). The angular displacement information is obtained by sensing differences in the optical pattern as the rotor (12) spins and is displaced about cross-axes, perpendicular to the spin axis.