System for Accurate Acoustic Presentation of Noise Sources

155 Pages·2010·4.06 MB·English

System for Accurate Acoustic
Presentation of Noise Sources
Authors:
Supervisor:
Esben MADSEN
Søren KRARUP OLESEN
Jorge COFIN˜O CO´RCOLES

AalborgUniversity
Acoustics
DepartmentofElectronicSystems
FrederikBajersVej7
9220AalborgØ
Telephone[phone]
http://acoustics.es.aau.dk/
Title: SystemforAccurateAcousticPresen-
Synopsis:
tationofNoiseSources
Projectterm:
Inthisthesis,asystemthatisabletoreproducethesound
Masterproject,springsemester2010 from noise sources as well as show the different levels
present at different distances and wind speeds has been
designed.
Projectgroup: This noise presentation system is composed by a small
10gr1063 computer (nanoLIAB) and a user interface designed for
it. An overview of the current Danish legislations re-
gardingnoiseevaluationofseveralkindsisgivensoitis
Groupmembers: knownwhattheguidelinestomeasurewindturbinenoise
EsbenMadsen are.
Next,anuserguideonhowtocarryoutmeasurementsof
JorgeCofin˜oCo´rcoles
windturbinenoiseaccordingtothestandardIEC61400
ispresentedandameasurementfollowingthisguidehas
taken place. The recorded data is evaluated to find pos-
Supervisor:
sible artifacts that may classify the signal as “corrupt”
SørenKrarupOlesen
or “clean” and a calibration of the system is done. The
designednoisepresentationsystemplaysbackthesound
Copies: 5 recordedfromawindturbineincombinationwithasetof
parameters that characterize the reproduced signal. The
Pages: 145 user interface provides a good overview of what is be-
ing played, by showing the user relevant data about the
Appendices: 1 CD with software and sourcethatisbeingplayedandenablestheusertochange
sources. thesettingsandtherebyplayingadifferentsound.
Finished3/62010
The contents of this report are freely available, but publication (with specification of source) may only be done af-
terarrangementwiththeauthors.

Thisreportismadeby:
EsbenMadsen
JorgeCofin˜oCo´rcoles
I
Contents
I InitialAnalysis 5
1 Relevantfields 6
1.1 GeneralsituationinnoiseassessmentinDenmark . . . . . . . . . . . . . . . . . 6
1.2 RoadNoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 RailwaysNoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.4 AirportNoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.5 WindTurbines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.6 Discussionandprojectlimitation . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2 PresentationofNoiselevels 19
2.1 BasicSystemRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 HardwarePlatforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3 DecisionsandProblemDefinition 24
3.1 ProblemDefinition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
II FieldMeasurementsandAnalysis 27
4 MeasurementProcedure 28
4.1 CaseStudy: WindTurbines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.2 WindTurbineNoiseMeasurementGuide . . . . . . . . . . . . . . . . . . . . . 30
5 Results 40
5.1 ConsiderationsandLimitations . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.2 Analysisoftheresults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.3 Post-processingoftheresults . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
II
III DataTreatment 51
6 EstimationofSignificantLevels 52
6.1 Sound pressure level and Equivalent A-weighted sound pressure level at a given
distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
6.2 Day-Evening-Nightlevelestimation,L . . . . . . . . . . . . . . . . . . . . 54
DEN
7 Preprocessing 57
7.1 Inspectionoftherecordings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
8 SystemEqualization 59
8.1 Gainmodification,MLSrecording . . . . . . . . . . . . . . . . . . . . . . . . . 59
8.2 Estimationofgainlinearities . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
8.3 Decisionsbasedobtainedresults . . . . . . . . . . . . . . . . . . . . . . . . . . 66
IV SystemDesignandImplementation 71
9 OverallDesign 72
9.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
9.2 DesignConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
9.3 Decisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
10 Platform 76
10.1 DescriptionofthenanoLIAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
10.2 Decisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
10.3 DesignandImplementationofthebasesystem . . . . . . . . . . . . . . . . . . 79
11 EmbeddedSoftware 83
11.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
11.2 DesignConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
11.3 UserGuide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
11.4 DesignandImplementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
12 UserInterface 89
12.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
12.2 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
12.3 DesignConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
12.4 DesignandImplementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
III
V Conclusions 99
13 SystemTest 100
13.1 Testdesign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
13.2 TestResults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
14 Conclusions 103
15 FuturePerspectives 105
Bibliography 107
ListofFigures 111
ListofTables 115
VI Appendix 117
A WindTurbineMeasurementProcedure 118
B MeasurementJournal 123
B.1 Characterizationofthewindturbine . . . . . . . . . . . . . . . . . . . . . . . . 123
B.2 Physicalenvironment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
B.3 Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
B.4 Acousticdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
B.5 Non-acousticdata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
C DevelopmentTools 134
C.1 InstallingtheCrossCompiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
C.2 MakeBaseScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
C.3 MakeWebPackageScript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
C.4 InstallWebUILocally . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
D NoiseplayProgram 137
D.1 Noiseplay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
D.2 Globalsettingsanddefinitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
D.3 Daemon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
IV
D.4 Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
D.5 WAVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
D.6 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
V
VI