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Decentralized control of sound radiation using iterative loop recovery
Noah H Schiller1, Randolph H Cabell, Chris R Fuller
1Structural Acoustics Branch, NASA Langley Research Center, Mail Stop 463, Hampton, Virginia 23681, USA. noah.h.schiller@nasa.gov
The Journal of the Acoustical Society of America
|October 26, 2010
Summary
A new iterative control strategy effectively reduces low-frequency sound radiation from stiffened panels, like those in aircraft. This robust method minimizes modeling errors without needing inter-unit communication, enhancing acoustic performance.
Area of Science:
- Acoustics and structural dynamics
- Control systems engineering
- Vibration analysis
Background:
- Decentralized model-based control is scalable but susceptible to performance degradation from unmodeled interactions between control units.
- Ensuring robustness in decentralized systems is challenging due to unknown modeling error bounds, often leading to overly conservative controllers.
- Periodic stiffening of panels is employed in structures like aircraft to enhance stiffness and reduce weight.
Purpose of the Study:
- To design a decentralized model-based control strategy for reducing low-frequency sound radiation from periodically stiffened panels.
- To develop an iterative approach utilizing frequency-shaped loop recovery to address modeling errors from neighboring control units.
- To evaluate the proposed control strategy's effectiveness and robustness on a representative stiffened aluminum panel model.
Main Methods:
- A decentralized model-based control strategy was designed.
- An iterative approach employing frequency-shaped loop recovery was developed to account for unmodeled interactions.
- Numerical simulations were conducted using a model of a stiffened aluminum panel, representative of aircraft sidewalls.
Main Results:
- The iterative control approach successfully reduced radiated sound power from the stiffened panel.
- The strategy achieved significant noise reduction without destabilizing adjacent control units.
- The method demonstrated robustness against modeling errors introduced by neighboring control loops.
Conclusions:
- The proposed iterative, decentralized control strategy is effective for reducing low-frequency sound radiation from stiffened panels.
- Frequency-shaped loop recovery provides a robust and relatively simple method to manage modeling errors in decentralized control systems.
- This approach offers a practical solution for acoustic performance enhancement in structures such as aircraft panels.
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