Target spectrum matrix definition for multiple-input- multiple-output control strategies applied on direct-field- acoustic-excitation tests

Blanco, Mariano Alvarez; Janssens, Karl; Bianciardi, Fabio

doi:10.1088/1742-6596/744/1/012179

Cited by 3 publications

(7 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This phenomenon has been reported elsewhere in the literature. Alvarez Blanco et al refer to it as the "Energy sink" [15]. Experiments here showed that increasing the number of control microphones increased this effect but tightened the monitor mic spread.…”

Section: Application To Dfan Drive Map Designmentioning

confidence: 54%

“…This encapsulates the SPL and coherence requirements. The optimal drive SDM 𝐒 dd (off-diagonals of which are complex, so include relative phase) can be found by [15]:…”

Section: Resultsmentioning

confidence: 99%

“…The difference is essentially whether the system is 'set and left', as is common in audio, or continually adjusted to meet a criterion. DFAN systems do the latter, typically with a Multi-Input Multi-Output (MIMO) controller, development of which is a research area in its own right [13][14][15].…”

Section: Control and Forward Versus Adaptive 'Equalisation'mentioning

confidence: 99%

“…At each frequency, this yields a matrix 𝐇 that relates drive amplitudes to pressure at the microphones 𝐩 by 𝐩 = 𝐇𝐝. DFAN control is, however, done in terms of power statistics [13,15]. This involves squaring 𝐝 and 𝐩, which in matrix notation is 𝐒 dd = 〈𝐝𝐝 𝐻 〉 and 𝐒 pp = 〈𝐩𝐩 𝐻 〉.…”

Section: Application To Dfan Drive Map Designmentioning

confidence: 99%

“…These are square and their diagonal gives the power in each signal. The off-diagonals are the square root of the product of the powers of a pair of signals, multiplied by their coherence and a phase term [15]. Hence, the diagonal of 𝐒 pp can be used to find the SPL at the microphones.…”

Section: Application To Dfan Drive Map Designmentioning

confidence: 99%

See 4 more Smart Citations

Analysis and Control of Acoustic Modes in Cylindrical Cavities with application to Direct Field Acoustic Noise (DFAN) Testing.

Hargreaves

2023

inter noise

View full text Add to dashboard Cite

It is well known that acoustic cavities have frequencies at which certain free-response 'modes' of propagation respond especially strongly. In the absence of significant damping, these cause peaks of high SPL in the frequency response as well as spatial non-uniformity and temporal ringing. The spatial non-uniformity is especially problematic since it means the room cannot be 'EQ'd' to compensate, since the SPL is different in different positions. This phenomenon has been studied extensively in the room acoustics literature and various strategies for mitigation proposed. Many of these make use of the theoretical mode shapes for a cuboid with a rigid boundary condition, since this is a common shape of room and a reasonable approximation for a solidly constructed wall. But modes exist for other shape spaces too. Of particular interest is the cylindrical cavity that is formed when large enclosing arrays of loudspeakers are used to perform high-intensity acoustic tests on space hardware. These possess problematic modes that can cause over-testing in some positions and under-testing in others. In this work, it is investigated how a simple FEM simulation can compute Q-factors for these modes and identify which will be problematic. How this might inform control system design is discussed.

show abstract

Section: Application To Dfan Drive Map Designmentioning

confidence: 54%

“…This encapsulates the SPL and coherence requirements. The optimal drive SDM 𝐒 dd (off-diagonals of which are complex, so include relative phase) can be found by [15]:…”

Section: Resultsmentioning

confidence: 99%

Section: Control and Forward Versus Adaptive 'Equalisation'mentioning

confidence: 99%

Section: Application To Dfan Drive Map Designmentioning

confidence: 99%

Section: Application To Dfan Drive Map Designmentioning

confidence: 99%

See 3 more Smart Citations

Analysis and Control of Acoustic Modes in Cylindrical Cavities with application to Direct Field Acoustic Noise (DFAN) Testing.

Hargreaves

2023

inter noise

View full text Add to dashboard Cite

show abstract

Validation of Lightweight Antenna Reflector Model for Environmental Acoustic Testing Operating Conditions

Blanco

Hallez²,

Carrella³

et al. 2018

Model Validation and Uncertainty Quantification, Volume 3

View full text Add to dashboard Cite

Acoustic Characterization of Vega Lift-off Environment via Ray Acoustics Modelling and Direct Field Acoustic Noise Testing

Garcia De Miguel,

Trentini,

Forrier

et al. 2024

Proceedings of the 10th Convention of the European Acoustics Association Forum Acusticum 2023

View full text Add to dashboard Cite

The lift-off phase during the space launch generates an extreme acoustic environment around the rocket fairing which must be considered for the qualification of large satellites. The sound waves, whose main source is the plume of gases coming from the rocket engine exhaust, travel through the fairing and impact the satellite, generating large vibrations in components with high surface to mass ratio. Dedicated models of the acoustic sources such as Distributed Source Method can be used to characterize the sound radiation from the jet of gasses. When it comes to modelling the spatial sound environments around the fairing, numerical approaches such as FEM or BEM are not well suited due to the large geometry of the problem and the need for extensive mesh refinements at high frequencies. In this context, geometrical acoustic methods such as ray acoustics provide a solution for full frequency simulations in very large geometries by assuming that the sound propagates along rays. Using this framework, this work focuses on the lift-off environment at the Vega launch pad and provides predictions of the sound pressure levels and directivity patterns around the payload fairing. Relevant considerations about how to replicate such conditions in laboratory tests are also discussed.

show abstract

Target spectrum matrix definition for multiple-input- multiple-output control strategies applied on direct-field- acoustic-excitation tests

Cited by 3 publications

References 13 publications

Analysis and Control of Acoustic Modes in Cylindrical Cavities with application to Direct Field Acoustic Noise (DFAN) Testing.

Analysis and Control of Acoustic Modes in Cylindrical Cavities with application to Direct Field Acoustic Noise (DFAN) Testing.

Validation of Lightweight Antenna Reflector Model for Environmental Acoustic Testing Operating Conditions

Acoustic Characterization of Vega Lift-off Environment via Ray Acoustics Modelling and Direct Field Acoustic Noise Testing

Contact Info

Product

Resources

About