FORCE AND PRESSURE/CONTACT INSTRUMENTATION FOR PARACHUTE HARNESSES

PARACHUTE AND HARNESS DESIGNS NEED TO BE IMPROVED IN ORDER TO PERMIT PARATROOPER DROPS AT HIGHER SPEEDS AND LOW ALTITUDES. LITTLE IS KNOWN ABOUT HOW OPENING SHOCK FORCES ARE TRANSMITTED TO THE PARACHUTE USER. INSTRUMENTATION IS NEEDED TO ASSESS THE FORCES IN THE VARIOUS STRAPS OF THE HARNESS DURING OPENING SHOCK. IN ADDITION, SENSORS ARE NEEDED WHICH WILL MEASURE CONTACT PRESSURE BETWEEN THE HARNESS OCCUPANT AND THE HARNESS DURING PARACHUTE OPENING. SUCH INSTRUMENTATION SHOULD BE NON-INTRUSIVE AND ACCURATE AND LOCATED AT CRITICAL POINTS ON THE HARNESS. CONTACT PRESSURES CAN BE MEASURED USING RECENTLY-DEVELOPED AND COMMERCIALLY AVAILABLE FORCE SENSITIVE RESISTORS (FSRS) WHICH CAN BE MOUNTED ON HARDNESS WEBBING. FORCES WITHIN WEBBING ELEMENTS CAN BE SENSED BY MEANS OF LOAD LINKS USING STRAIN GAGES SEWN TO THE WEBBING. BY PROVIDING A SMALL BATTERY, BRIDGE RESISTORS, AND AN INTEGRATED-CIRCUIT DC AMPLIFIER, GOOD SIGNAL STRENGTH CAN BE OBTAINED FROM THE TRANSDUCERS, MINIMIZING THE NEED FOR BULKY MULTI-CONDUCTOR SHIELDING CABLES.