SBIR-STTR Award

The objective of this project is to determine the feasibility of developing Class 28 IO KW (12.5 EVA) and 30 KW (37.5 KVA) auxiliary power units that are lighter than present M D inventory with 120 volt A.C. - 3% at 60 HZ at a .8 power factor that have maximum noise levels of 7SdB (A) at one meter outside of the shelter and SSdB (A) inside the human factors compartment. Vibrational oscillation is not to exceed 2 ft/sec 2 peak-to-peak. The objective will be achieved by use of turbocharged light weight diesel engines with a 3600 RPM .8 power factor designed alternator for the IO KW APU, and an 1800 RPM .8 power factor designed alternator for the 30 KW APU. All mechanical and electronic gear for vibration and sound cancellation will be integrated with complex software interfaced to mechanical actuators to achieve the objective set forth above.

Benefits:
Maximize the use of military shelters relative to weight vibration and noise as these negative factors now relate to payload., human comfort, and sophisticated on board equipment performance and utilization. Commercial application of the developed system in whole or part would apply to the automotive industry, commercial vehicles, mining equipment, transport refrigeration equipment, railroad equipment, aircraft, recreational vehicle sleeping quarters, and high noise level work stations in industry on a potentially universal basis.

Keywords:
Shelter Weight APU Active Vibration Cancellation Noise Computerized

The Phase II effort will be to design and build a light weight three Phrase 10 KW API in accordance with MIL-STD 1332B Class 2B with integrated subsystems that: (1) reduce noise at points one meter outside of the shelter from 85 dB(A) to less than a maximum of 55 dB(A), and inside the shelter workspace to less than a maximum of 55 dB(A); (2) reduce vibration inside the shelter work space to less than 0.04 g P-P at frequencies below 8 Hz, and at frequencies of 8 Hz and above reduce vibration in accordance with MIL-STD-1472D, Page 179, Figure 43. The integrated active noise and vibration cancellation subsystem will use DSP hardware with emphasis on adaptive nonlinear polynomial neural network algorithms, and will utilize electrical control actuators and sensing accelerometers mounted on the APU and the shelter/vehicle, plus a shelter/vehicle inertial displacement sensor for vibration sensing and control. The noise cancellation approach planned will eliminate the conventional upstream reference microphone and make direct use of feedback from the error microphone. The fee forward microphone will be replaced by an electrical reference signal from the alternator.