STRAIN RATE SENSOR FOR VIBRATION CONTROL IN LARGE FLEXIBLE STRUCTURES

A TRANSDUCER WHICH CAN DIRECTLY MEASURE THE TIME RATE OF CHANGE OF STRAIN (STRAIN RATE) IN A VIBRATING STRUCTURE IS BEING DEVELOPED. THERE ARE PRESENTLY NO TRANSDUCERS AVAILABLE THAT CAN PRODUCE THIS STRAIN RATE INFORMATION. THIS HAS CREATED DIFFICULTIES IN VIBRATION CONTROL BECAUSE ACTIVE CONTROL CANNOT SIGNIFICANTLY AFFECT STRUCTURAL DAMPING UNLESS RATE-OF-CHANGE DATA IS ONE OF THE STRUCTURAL CONTROL FEEDBACK VARIABLES. THE TRANSDUCER DEVELOPED ON THIS PROGRAM, THE VARIABLE RELUCTANCE TRANSFORMER (VRT) STRAIN RATE SENSOR, IS A SMALL FLAT TRANSFORMER THAT MOUNTS DIRECTLY TO A STRUCTURE MUCH LIKE A CONVENTIONAL STRAIN GAUGE. SUCCESSFUL DEVELOPMENT OF THE REAL-TIME STRAIN RATE SENSOR ALLOWS THE MOTION OF LARGE SPACE STRUCTURES TO BE MEASURED MORE DIRECTLY; AND PERMITS MORE EFFECTIVE AND LIGHTER WEIGHT ACTIVE STRUCTURAL CONTROL SYSTEMS FOR MILITARY AND COMMERCIAL SPACE PLATFORMS.