Servo Controlled Rapid Response Anti-G Valve

摘要

Current anti-G suits inflate under control of an anti-G valve and apply pressure to the abdominal and leg areas to prevent blood pooling in the lower portions of the body. The anti-G valves employ a spring and mass construction which regulates air flow to the suit in direct proportion to the amount by which the applied G force exceeds a nominal 2G breakout force. This mechanical method, however, does not permit rapid filling of the suit required during high onset G profiles generated by high performance VA/VF aircraft. This Center has designed, constructed, and tested a prototype servo controlled rapid response anti-G valve system. This system, which employs a pressure transducer located in the valve outlet line but modified to represent the pressure in the anti-G suit as the feedback signal, is capable of pressurizing the suit on a schedule which closely coincides with that of a rapidly applied G profile. In addition, this new valve is capable of improved system reliability. A series of manned tests were conducted on the NAVAIRDEVCEN human centrifuge to compare the protection provided to relaxed and straining subjects exposed to rapid onset G-profiles by the current mechanical valve system and the servo valve system. The servo valve system proved superior to the mechanical system exhibiting an average 0.5G tolerance improvement when the subjects were in a relaxed state and an average 1.3G tolerance improvement when the subjects were in an M-1 straining state.