MUTUAL INDUCTIVE SENSING FOR IR SEEKERS

AN INNOVATIVE APPLICATION OF THE POSITION DEPENDENCE OF THE MUTUAL INDUCTANCE BETWEEN TWO COILS IS PROPOSED FOR SENSING THE ROTATIONAL PARAMETERS REQUIRED BY A FREE GYRO SEEKER OF A MULTI-SPECTRUM GUIDANCESYSTEM. A SET OF SERIES RESONANT STATIC TRANSMITTING COILS EXCITE ONE OR MORE TUNED PASSIVE COILS MOVING WITH THE GYRO. THE ROTATIONAL POSITION AND ITS RATE OF CHANGE ARE DETERMINED FROM THE MEASURED COUPLING BETWEEN MOVING AND FIXED COILS. THIS IS ACHIEVED BY CORRELATING THE MUTUAL INDUCTANCE WITH THE ANGULAR SEPARATION BETWEEN THE TWO COILS. THE COMBINATION OF REAL TIME DATA OBTAINED FROM THE COMPLETE SETOF TRANSMITTERS CAN BE DIGITALLY DECONVOLUTED TO OBTAIN POSITION ANDRATE INFORMATION OR USED DIRECTLY WITH ANALOG PROCESSING. SINCE THE COUPLING IS A FUNCTION OF GEOMETRY, ARBITRARILY PRECISE POSITION DETERMINATIONS CAN BE MADE WITH A SUITABLE COMPLEMENT OF COILS AND RESONANT FREQUENCIES PROVIDING NOISE SUPPRESSION, SIGNAL PROCESSING, AND MECHANICAL TOLERANCES ARE COMPATIBLE. THE TECHNIQUE IS INHERENTLY NOISE DISCRIMINATING SINCE ULTRASONIC FREQUENCIES ARE USED IN RESONANTCIRCUITS, YET ESPECIALLY COMPATIBLE WITH THE OPTICS ASSOCIATED WITH IR DETECTING SYSTEM. FURTHER, THESE FREQUENCIES ALLOW KILOHERTZ DATARATES. IN PHASE I, A GEOMETRICALLY APPROPRIATE, RUDIMENTARY SENSOR WILL BE DESIGFIED AND TESTED IN A PROOF OF PRINCIPLE DEMONSTRATION.