Preliminary results of a MIMO Harmonic Controller to perform active sound power attenuation with a RHAPSODI
Bibliographic record
Abstract
A Harmonic Acoustic Pneumatic Source (HAPS) is an acoustic device developed to perform active harmonic sound control in turbofans. In order to develop a demonstrator, a ring of multiple HAPS (RHAPSODI) is assembled around a cylindrical duct and a dedicated MIMO harmonic controller was developed to perform active sound power attenuation. The control objective is to develop a MIMO feedback controller adapted to multiple HAPS and using in-duct microphones close to them. Three points are addressed : the control of HAPS as a mechanical modulator, the in-duct error microphones located in the near field of HAPS, and the tuning of the controller. The presented method is based on a dedicated MIMO feedback controller of complex envelops with compensation of near field. The compensation matrix of the near field is tuned during a learning phase based on the measurement of a set of optimal commands experimentally obtained with a dedicated controller using the out-duct microphones. When the matrix of compensation is estimated, the MIMO controller using induct microphones can be used. Preliminary experimental results show that a RHAPSODI of 5 HAPS can attenuate the first harmonic of a radiated tonal sound power by more than 20dB.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".