Fluidic notch filters
Abstract
Ten notch-filter circuits with biquadratic transfer functions are described. Notch filters are used in control systems to prevent instabilities due to mechanical resonances. The electronic circuit literature was searched to find circuits with biquadratic transfer functions that could be implemented with fluidic amplifiers. The amplifiers are assumed to have equal input and output impedances, and all high-gain amplifiers used are assumed to have a pressure gain of 2,000. Using these characteristics, the frequency response of the circuits is calculated using a digital, circuit-analysis program. The best circuit, based on accuracy in producing a required transfer function for the M60A1 tank control system, gain insensitivity, and least number of compliances (bellows) requires three high-gain amplifiers. Advantages and disadvantages of all the circuits are discussed.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- January 1976
- Bibcode:
- 1976STIN...7621441R
- Keywords:
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- Fluid Filters;
- Fluidic Circuits;
- Transfer Functions;
- Control Stability;
- Dynamic Response;
- Fluid Amplifiers;
- Resonant Frequencies;
- Fluid Mechanics and Heat Transfer