Lecture 2 BRecent advances in active noise and vibration controlein

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Recent advances in active noise and vibration control

Marie Curie Graduate School on Vehicle Mechatronics & Dynamics

February 5-8, 2013 (Heverlee, Belgium)

Thilo BeinFraunhofer LBF, Darmstadt

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Introduction

In the year 2050 more than 9 bn. humans will live on earth. (UN)

In the next 30 years 450 mill. Chinese people will live in cities, which are not existing, yet.

(Lutz Engelke, Trias Projektgesellschaft mbH, auto motor sport-Kongress 2010)

Up to the year 2030 appr. 500 cities will exist with a population over amillion citizens. 27 of them will be megacities.

(8th world congress of network Metropolis - World Ass. of Major Metropolises)

Increasing demand on urban mobility

[www.wienweb.at]www.cai.blogware.com

… with zero-emission ideally

Any public or commercial use requires the agreement of the author.

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Outline

Introduction

Brief introduction to adaptronics

Selected enabling technologies

Examples from recent projects

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Challenges for Future Mobility

[Source: Grotendorst, Continental, 2009]

Limited FuelPrice / availability of oil Increasing traffic (passenger and transport)

Reduced emissions CO2 Emissions DevelopmentC02 emission development

160130 95 70

2006 2012 2020 2025

www.in-brasilien.de

in g CO2/km

Bild: AP

Until 2030 in the transport sector, the predicted increase of fuel demand totals 55 %

US Tier2Bin5

EU 5 Sept-2009

Phase IIJan-2010

NationalJan-2010

Phase IIIJan-2013

EU6Sept-2014

PMNOX

CO

HC

§

Exh

au

st g

as

em

issi

on

s


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Lightweight as development target

-10%

Mass reduction: > 250 kg

Base data: Affenzeller, AVL Vehicle mass [kg]

The mass of the vehicle must be reduced

• to meet the CO2

targets of ICE-drivencars(-100 kg = 8.5 gCO2/km)

• to compensate forthe mass of thebattery

• to reduce the mass ofthe battery

• to extend the rangeof HEV/FEV

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Trend towards multi-material design

High Volume Maturity Phase

Po

ten

tials

of

Lig

htw

eig

ht

Desi

gn

Steel Designtoday

OptimizedSteel Structures

New Ligthweight

Designs

Fibre reinforcedPlastics

CFK-Designs

AI -Structures

Steel-ALDesign

Plastic-Metal-Hybrids

Source: M.Goede, VW Group Research, SLC


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New Demands on NVH particular for Electrified Vehicles

Quelle: Porsche

Taking out Powertrain Noise

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New Demands on NVH particular for Electrified Vehicles

X

X

X

X

X

X

loss of masking effects

more high frequentcontent or annoyingtonal contributions

new transmissionpathes

new multi-materials components with integrated functions

integration of the sound package into load carrying structures

application of smart structures


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Adaptronics (smart structures) offers solutions

50.00 200.00HzMIC: VL (CH30)

4 .00

75.00

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60.00

70.00

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s

0.00

0.30

Am

plit

ude

Pa

Spectrum MIC: VL WF 181 [0-90 s]

50.00 200.00HzMIC: VL (CH30)

4 .00

72.00

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plit

ude

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Spectrum MIC: VL WF 181 [0-90 s]

interior noise reductionby means of active systems

improved crashworthinessby means of active systems

active passive

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Noise as one of the societal challenges

stress

high blood pressure

hardness of hearingand deafness

heart attack

learning difficulties bychildren

90 dB(A)

95 dB(A)

110 dB(A)

100 dB(A)

120 dB(A)

100 Mio. people within the EU are seriously affected by noise

Junction Frankfurt-Süd is themost congested transport hub in Europe

Economic damage caused bynoise in the EU about 13 – 38 bn. € / year

noise map of the airport Frankfurt


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Adaptronics (smart structures) offers solutions

active noise insulating windows and facades

X: control off

X: control on

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Outline

Introduction





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Adaptronics ... inspired by nature...

sensor and actuatorfunctions are integratedinto structures to controltheir mechanicalproperties in a „smart“ way

learning from nature - Adaptronics

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Adaptronics ... inspired by nature ...

Application areas

Active vibration control

Active noise control (ASAC)

Active form and position control

Structure Health Monitoring

Customer‘s advantages

Optimization of structural loadings, durability, lightweight design,

Additional functions

Increase of comfort and safety

On-demand maintenance


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Example: Active vibration control

Control of thestructure-borne soundpath

Brain

Nerves Muscelsb)

Sensor Controller

Actuatorc)

a)

FS

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Example: Shunt damping


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The basic smart (multifunctional) material

PiezoceramicsPiezopolymereElectrostrict. ceramicsElectroviskose FluidsPolymergele

Magnetostrict. AlloysMagnetoviskose Fluids

Shape Memory AlloysMemorypolymereHybrid material systemsPolymergele

PolymergeleElectrostrictive materialsPhotomechanic MaterialsOptical Fibres

Electric Field

Magnetic Field

Heat

Light

ElectricCharge

Resistance, Inductivity

Resistance

Light Intensity

Actuator

SensorETREMA

LPA

Mechanical force,

deformation,etc…

Quelle: mNemoScience

Quelle: EMK, TU Darmstadt

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Some definitions (LBF)

Passive systems: systems without external energy (e.g. energy recovery, piezoelectric damping)

Semi-active systems: low external energy required to supply electronics (e.g. electrical proof mass absorber)

Active systems: external energy required to drive actuators (fully controlled active system)

Systems can be designed such that they adapt to changing environmental conditions !


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Outline

Introduction




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Materials & Design: seismic sensor for active mounts

Source: TUD-MaWi, L. Alff & LBF

Direct pulsed-laser deposition of PZT on spring steel(transparent thin layers)

design of the seismic sensor

Frequency range: 0,7 – 100 Hz Eigenfrequency: >500 Hz)Sensitivity: 1 V / m/s²Dimension: 68 x 40 x 33,5 mm³


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Materials & Design: piezoelectret accelerometer for ASAC

Source: TUD-MaWi & TUD-SzMJ. Hillenbrand, P. Pondrom

piezoelectret, stable up to 90°C

12 mm

40 mm

shielded sensor with a seismic mass

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Materials & Design: piezoelectret accelerometer for ASAC

10 100 10001

10

100

0,1 15

6

7

8

9

10

11

12

13

14

15 Wandler LP01 - Frequenz: 100 Hz Wandler LP01 - Frequenz: 200 Hz Wandler LP01 - Frequenz: 500 Hz Wandler LP01 - Frequenz: 1000 Hz Wandler LP01 - Frequenz: 1500 Hz Wandler LP01 - Frequenz: 2000 Hz

sen

siti

vity

[pC

/g]

sen

siti

vity

[pC

/g]

frequency [Hz]

acceleration [g]

Source: TUD-MaWi & TUD-SzMJ. Hillenbrand, P. Pondrom


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Manufacturing: piezoresistive strain sensors

Source: TUD-EMK, Werthschützky & RauschTUD-IDD, Dörsam & Griesheimer

Si-Chips high degree of miniaturisation (A = 0,25 mm2)

high sensitivity

(50x higher than conventional DMS)

Printed Low-Cost-Sensors integrated in the manufacturing process

sensitivity similiar conventional DMS

characteristics under static loading

Si-Chips printed

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Integration & Manufacturing

Source: TUD-IDD, TUD-PTW & TUD-PtUDörsam, Abele, Groche, et.al.

Blech1. Schicht Iso2. Schicht Iso Silberstruktur

Use of screen printing and Inkjet to produce functional structures

Maintaining the functionality of the sensor after forming processes

Isolation: up to 35 % strainSilver: up to 33 % strain

Functionality up to 20 % strain maintained


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Integration & Manufacturing

Printed circuit pathes

Printed sensors

embedded actuators

Embedded circuit pathes

Smart (curved) panels for active structural acoustic control (ASAC)

Source: TUD-IDD, TUD-PTW & TUD-PtUDörsam, Abele, Groche, et.al.

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Selective laser melting of active struts

Source: TUD-PTW & LBF

CAD-Modell

integration of actuator

active strut

0 300 600 900 1200Kraft [N]

0

6

12

18

24

30

36

Deh

nun

g [µ

m]

50 V100 V150 V200 V


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Numerical and experimental simulation - the acoustic box

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Numerical and experimental simulation - the acoustic box

50 100 150 200 250 300 350 400-50

-40

-30

-20

-10

0

10

Frequency [Hz

G(j)

in d

B

w/o active damping

w active damping

passive

active


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Vibration measurements - example double-glaze window

3D-Scanning-Laservibrome

ter

clamped 4 mm

aluminium plate

rigid walls

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Vibration measurements of a double-glaze window

Deflection shapes of a double-glazed window

both panes in phase

both panes in antiphase

compression an decompression of air gap

no excitation of air gap


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Active Structural Acoustic Control (ASAC)

Alternative Excitation with

an electrodynamic

Shaker

Excitationwith a 6x

loudspeakerSystem

Piezoceramicpatch

Microphonefor

controller‘serror signal

Experimental Setup

view from top

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Active Structural Acoustic Control (ASAC)

Sound pressure level of the error microphonewhen excited with a rotary machine sound

28 dB

21 dB

X: control off

X: control on

Frequency Hz

So

un

d p

ress

ure

level

SPL

[dB

]


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Shunted damping of periodic structures

Adding an ohmic resistance and an inductance to the capacity of the piezo-ceramics an electric circuit can be obtained behaving like a proof-massabsorber.

each of the twelvepiezos work as a combined sensor-actuator

12x electriccircuits ascontrollers

excitationForce

Semi-passive vibration reduction of lightly damped structures (4mm aluminium plate)

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Shunted damping of periodic structures

Averaged Frequency Response Function [velocity/ force] shunt damping tuned to 1560 Hz

FrequencyHz

FR

F v

/F [

dB

]

X: control off

X : electrical resistance = 1 kΩ

X : electrical resistance = 1 Ω


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Adaptive Helmholtz resonator

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Measurement at a defined frequency of 197 Hz

w/o HR w HR

100 150 200 250 300 350 400 450 50010

5

106

107

108

109

Frequenz in Hz

FR

F in

Pa/

m3

Referenz

197 Hz

-13 dB


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acoustic box

Adaptive Helmholtz-Resonator

CAN Bus

Measurement ofthe interior acoustic

Power supplyof the motor

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100 150 200 250 300 350 400 450 50010

5

106

107

108

109

Frequenz in Hz

FR

F in

Pa/

m3

Referenz

adaptiver HR

100 150 200 250 300 350 400 450 50010

5

106

107

108

109

1010

Frequenz in Hz

FR

F in

Pa/

m3

ohne HR

mit HR

FDTD simulation

measurements


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Adaptive lightweight absorbers

Source: h_da & LBF

design testingmanufacturing

0.00 300.00Hz

-20.00

30.00

dBU

nkno

wn

()

0.00

1.00

Am

plitu

de

72.5470.70

F Sum FRF Kontakte kurzgeschlossenF Sum FRF Kontakte offen

Tra

nsm

issi

bili

tät

[(m

/s²)

/N]

Frequenz [Hz]0.00 300.00Hz

-20.00

30.00

dBU

nkno

wn

()

0.00

1.00

Am

plitu

de

72.5470.70

F Sum FRF Kontakte kurzgeschlossenF Sum FRF Kontakte offen

Tra

nsm

issi

bili

tät

[(m

/s²)

/N]

Frequenz [Hz]

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High performing active mounts

Source: LBF

hybrid, active mount with parallel load application


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Outline

Introduction




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Application of Smart Structures - Examples

discrete elastic mountingse.g. suspension strutAVC / ASAC

planar actuatorse.g. damping of side-door

ASACswitching systems

e.g. variable stiffness for side-crash Safety

Vibration-based condition monitoringe.g. tie rod

SHM

Concept

• AVC – Active Vibration Control - Vibrations

• ASAC – Active Structural Acoustic Control – Vibro-Acoustics

• SHM – Structural Health Monitoring

• Safety


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discrete interfaces to isolate / damp motors, aggregates, etc.

distributed flat transducers to damp plate-like structures e.g. for oil pan, door, housing

add-on systems e.g. for active or adaptive absorption or broad band vibration reduction with proof mass absorbers, inertial exciters / compensators

new actuators e.g. for switching / modification of the load situation in structures e.g. for crash applications and load control, substitution of conventional drives (electric flap drives), smart fluid dampers

Structure integrated damage (health) monitoring (vibration based)

Systems for energy harvesting

via active, semi-active or passive approaches – both adaptronic and mechatronic

Prominent active structure solutions from market view

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Concepts for active engine mounts

Passive Semi-passive Active Active Active

Adaptive neutralizer

Active mount Active mount Inertial mass actuator

Disturbance Adaptive stiffness

Host structure Viscous element

Inertial mass Active element (force generator)


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Hybrid engine mount

Assembled ActiveEngine Mount

Installation of Active Mount in the Car

ControlSensor

Monitoring Sensors

piezo based active engine mount for 2nd order attenuation

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Hybrid engine mount

results for SPL controlresults for acceleration control (z)

test at chassis dynacontrol system


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Next Generation Hybrid Mount – Opel Astra

Mounting point acceleration 2nd gear Run-up (60 sec) 30% throttle position Error sensor – mounting point acceleration

2000 2500 3000 3500 4000-40

-35

-30

-25

-20

-15

-10

-5

0

rpm [1/min]

Mo

un

tin

g p

oin

t acc

ele

rati

on

[d

B r

e 1

m/s

2]

Second Order Cut

Serial mount

Active mount - uncontrolled

Active mount - controlled

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2000 2500 3000 3500 400035

40

45

50

55

60

65

70

rpm 1/min

sou

nd

pre

ssu

re [

dB

(A)

re 2

0

Pa]

Sound pressure dB(A)

Serial mount

Active mount - uncontrolled

Active mount - controlled

Driver’s ear sound pressure 2nd gear Run-up (60 sec) 30% throttle position Error sensor – driver’s ear sound pressure


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driver’s ear sound pressuremounting point acceleration

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Sub-Frame with Smart Mountings


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Sub-Frame with Smart Mountings

Test drives at constant speed of 40 km/h Accelerations at two points at the car body

control ofcontrol on

control ofcontrol on

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Active Engine Mount – Torque Arm

stroke amplified actuator bending beam disk spring


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Measurement with 1.5 kg mass

- Resonance frequency 24 Hz

- Block force 6,75N (at 250 V pp)


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Step sine excitation

Acceleration at the exciter = 1st engine order

Error signal = Acceleration chassis side

2…8 dB vibration reduction from 50Hz to 90Hz

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Recent advances in active noise and vibration control

Thank you for your attention!


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Lecture 2 BRecent advances in active noise and vibration controlein