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

13th International Conference on Motion and Vibration Control; 12th International Conference on Recent Advances in Structural Dynamics

Blanco, M. Alvarez^1 ; Janssens, K.^1 ; Bianciardi, F.^1

Division Manager RTD, Siemens Industry Software NV, Leuven, Belgium^1

关键词: Control strategies;    Environmental acoustics;    Initial conditions;    Interference patterns;    Qualification testing;    Sound pressure level;    System configurations;    Target definitions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012179/pdf
DOI  :  10.1088/1742-6596/744/1/012179

来源: IOP

【 摘 要 】

During the last two decades there have been several improvements on environmental acoustic qualification testing for launch and space vehicles. Direct field excitation (DFAX) tests using Multiple-Input-Multiple-Output (MIMO) control strategies seems to become the most cost-efficient way for component and subsystem acoustic testing. However there are still some concerns about the uniformity and diffusivity of the acoustic field produced by direct field testing. Lately, much of the documented progresses aimed to solve the non-uniformity of the field by altering the sound pressure level requirement, limiting responses and adding or modifying control microphones positions. However, the first two solutions imply modifying the qualification criteria, which could lead to under-testing, potentially risking the mission. Furthermore, adding or moving control microphones prematurely changes the system configuration, even if it is an optimal geometric layout in terms of wave interference patterns control. This research investigates the target definition as an initial condition for the acoustic MIMO control. Through experiments it is shown that for a given system configuration the performance of a DFAX test strongly depends on the target definition procedure. As output of this research a set of descriptors are presented describing a phenomenon defined as "Energy- sink".