LMS Sound Camera and Sound Source Localization · 2017-11-02 · LMS Sound Camera on LMS Test.Lab...

LMS Sound Camera andSound Source LocalizationFast & Versatile Sound Source Localization

Realize innovation.Unrestricted © Siemens AG 2017

Unrestricted © Siemens AG 20172017.MM.DD Siemens PLM Software

Sound Source LocalizationWhat is it about?

Sound Source Localization• Technique to localize and visualize

sound at the source• With a one-shot measurement

using an array of microphones• Accelerates troubleshooting and

confirms that you work on the rightproblem

Typical applications:• Acoustic transparency• Locating noise phenomena• Comparing variants of components• Quantification and ranking of

source contributions

‘Sounds like it’s comingfrom the engine’?


Introducing LMS Sound CameraThe Digital Microphone Array for Sound Source Localization

Performantover wide frequency

range

in far and nearfield

Versatilemodular design

any operatingcondition

for lab and field

Insighton Test.Lab withmore channels &

improvedperformance

Industrialfast & easy to use

robust design


• Support of 4 additional sensors on LMS Sound Camera• Parallel acquisition with LMS SCADAS using Test.Lab• Access to Advanced analysis like: iNAH, Deconvolution,

combustion analysis,…• Enhanced Productivity using Batch Processing

LMS Sound CameraFast & Versatile Sound Source Localization solutionusing digital microphone array with integrated electronics

LMS Sound CameraDigital Array SoftwareLMS Sound Camera

Digital Array Software

Accelerated Troubleshootingwith dedicated standalone software

datadata

LMS Sound CameraDigital Array

Modular microphone arraywith integrated electronics

Center part : 45 micsShort arms: 81 micsLong arms:117 mics

LMS Sound CameraDigital Array

Modular microphone arraywith integrated electronics

Center part : 45 micsShort arms: 81 micsLong arms:117 mics

LMS Test.Labsoftware

LMS Test.Labsoftware

Engineering Insightwith LMS Test.Lab & LMS SCADAS front-end

• Easy setup. Short time to first result: <5mins• Real-time results & reprocessing of recordings• In the field testing & comparison of results• Report & share results as video & pictures• Additional processing using LMS Test.Lab


LMS Sound Camera Digital ArrayVersatile and Robust

Industrial & Robust• Digital microphone array (MEMS)

with all electronics integrated• Connects directly to PC with a single

cable. No frontend required.• Robust but light industrial design• Wide frequency range 50-20kHz

All-round array• Can be extended with short

arms to increase array diameter• All-round array optimized for

farfield and nearfield• Wide angle lens allows viewing

entire object at close distance

Adapts to many applications• Can be extended with long arms to

increase array diameter• Large diameter offers excellent spatial

resolution in low frequency• Suited for far-field measurements and

quantification applications


LMS Sound Camera Digital ArrayModular array with 3 different sizes

Center Short Arms Long armsTypical Usage Trouble-shooting, handheld All-round array Advanced, outdoorTypical distance nearfield <0.5m nearfield & far field <1m nearfield & far field (~0.3 to >2m)Typical freq. range 1000*-20kHz 400*-20kHz 200*-10kHzDiameter & mics 30cm with 45 mics 60cm with 81 mics 150cm with 117 micsDynamic range** 14 dB 16 dB 12 dB

* With beamforming/nearfield focusing. Can be improved with iNAH** Simulated results. Experimental results typically 1-2dB lower.

Unrestricted © Siemens AG 20172017.MM.DDPage 8 Siemens PLM Software

Introducing: Sound Source propagation techniques


BeamformingBasic Principle in time domain

P1(t)

P2(t)

P3(t)

S(t)Propagation of source signal:

Back-propagation of measured signals:

d1

d2

d3

P1(t)

P2(t)

P3(t)

++ =

++ =

++ =

d11

d21

d31

d13

d23

d33

S1(t)

S2(t)

( ) = +

( ) = −Back propagatedmic signals

impact


Beamforming – Strength and weakness

1/3 oct. 2000 Hz

1/3 oct. 500 Hz

1/3 oct. 6000 Hz

Distance between speakers 27 cm

Measurementdistance

Overview

Beamforming

60cm

Good spatail resolution in high frrequencies

Poor spatail resolution in low frrequencies


LMS Sound Camera Digital Array softwareDedicated standalone software

Real-time source localization• Changes in interesting frequency

ranges, averaging and displaysettings are applied immediately.

• Allows locating sources quickly.• Single sheet application.

Easy reporting of results• Results can be stored as

picture and video• Annotated with key data and

user comments.• raw data can be also be

shared for further analysis.

Analysis and Comparison• Reference display and extended

display scales• For quick side-by-side comparison

of results and absolute levels.• Allows comparing different product

variants and operational conditions.


LMS Sound Camera Digital Array softwareDesigned for movement

Moving operator• Moving from the farfield into the

nearfield• Real-time nearfield focusing gives

best spatial resolution• Move around object to locate in

space

Moving object• Assess transient, impulsive

operational conditions• Analyze recording at high frame rate• For balanced and refined source

results apply short-timeexponentional averaging

• 25 frames per second high precision

FARFIELD picture NEARFIELD pictureNEARFIELD picture

different angle


LMS Sound Camera on LMS Test.LabMeasure more data channels

Direct connection• LMS Sound Camera connects

directly to LMS Test.Lab• Use 4 additional AC/ICP sensors

on LMS Sound Camera• Correlate source locations with

other analysis results

Multi-front-end mode• For more channels, parallel

acquisition with LMS SCADASMobile/ Recorder

• Combine with advanced tacho,digital sensors,

• Synchronization from digital irig-boutput on SCADAS Mobile.

CAN

tacho


LMS Sound Camera on LMS Test.LabIncrease engineering insight

Leveraging LMS Test.Lab platform• Test complex scenarios like engine

run-ups, tracked on rotationalspeed

• Correlate sound source locationsto analyses like orders, soundquality metrics.

Improved spatial resolution• For source separation and

increased spatial resolution inlow frequency with iNAH orDeconvolution

• Quantify source strength byaccurately estimate sound powercontribution of sources

Improved Productivity• Side-by-Side comparison of

holograms & contribution spectra• Batch processing for systematic test

approaches and high demand• Fast calculations optimized on

graphical card


Improved processingNearfield Acoustic Holography

Used byBeamforming

Used by nearfieldholography


Improved processingBeamforming – Focalization – i-NAH

► High DefinitionAcousticCamera – 3-in-1solutionBeamforming –Focalization – i-NAH

1250Hz1/3 octave

4000Hz1/3

octave

500Hz1/3 octave

Beamforming (50cm) Focalization (10cm) iNAH (10cm)

x2

x?x2

One measurement in near-field


Decomposition engine noiseusing Cyclic Wienerfilter approach

Understand contribution combustion noise& “other mechanical noises” from theengine”

Target setting & assessment duringdevelopment cycle

Alternative ‘coherence’ method in timedomain for cyclic impulsive events

engine noise = combustion noise + residue


Improved processingRotating Sources

18 copyright LMS International - 2013

Fixed geometry Rotating geometry


Improved processingDeconvolution Process

Delta

In first instance a monopole distribution, in the sourceplane, is assumed to be as indicated by thebeamforming.

With each iteration a new source distribution iscomputed to reduce the Delta between the computedpressure distribution at measurement plane and themeasured one.

ForwardPropagation

ForwardPropagation

Delta

Step 1: beamforming

Step 3 (Iterated): NewSource distribution

Step 2: Errorcalculation


Improved processing:Deconvolution Example

Beamforming Map

Using Far-Field Deconvolution it is possible toimprove the localization and increase the

dynamic range from 8dB to 20dB

Between 1kHz and2kHz


Improved productivityBatch processing

Process frequency/rpm ranges fordifferent

• Loading conditions• Configurations

All at the same time.


Improved productivityCompare different results

Thank you for yourattention!

LMS Sound Camera and Sound Source Localization · 2017-11-02 · LMS Sound Camera on LMS Test.Lab...

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