nvh optimisation of an electric parking brake · or used for manufacturing, without the prior...
TRANSCRIPT
NVH Optimisation of anElectric Parking Brake
H.-J. Griebel, T. Treyde, T. KasterTRW Koblenz
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EPB Noise Optimisation Process
• Use of NVH development tools
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EPB Noise Optimisation Process
• Use of NVH development tools
• Efficient development process
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EPB Noise Optimisation Process
• Use of NVH development tools
• Efficient development process
• Effective noise reduction
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Electric Parking Brake (EPB)
• parking the vehicle at 30% hill
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Electric Parking Brake
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EPB Noise
... is not a vehicle interior noise issue
... is an exterior noise concern
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Noise Characteristic
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Howlingnoise
Wavelet analysis
apply
Speed reduction
Noise Characteristic
1000 Hz
2000 Hz3000 Hz
6040
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
• Apply noise comparable torelease noise, but mirrored
• Noise annoying mainly duringapply „howling sound“
• Structural resonance at 1400Hz in combination with speedreduction
Howlingnoise
Wavelet analysis
apply release
Speed reduction
Noise Characteristic
Structural resonance
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
• Impact hammer test atthe rotor shows nosignificant resonance at1400 Hz
• The cause of thestructural resonance is notthe rotor
Noise Radiation
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
• Impact hammer test at the rotor showsno significant resonance at 1400 Hz
• The cause of the structural resonance isnot the rotor
Noise Radiation
• cause of the noise is not the caliper
• cause seems to be the actuator
Release
Laser holography0
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
release
releaseapply
=> housing cover showes big amplitudes
Laser Holography of Housing
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
=>
Modal Analysis at 1457 Hz
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
=>
Modal Analysis at 1529 Hz
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Calculated Noise Radiation
DeformedDeformedplotplot
PressurePressure
Displ, XDispl, Xcompcomp
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Housing Modification
Baseline shell meshBaseline shell meshBaseline solid meshBaseline solid mesh
Modification solid meshModification solid mesh
Improvement not sufficient
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Actuator Design
drive gear; 15 teath
motor; 5 poles
toothed belt
gear
swash plate
sliding block
cover
housing
Cover removed
connector
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Detailed Noise Analysisclearance compensation apply
structural resonance
gear meshing noise
5th motor order
rattle noise
harmonic ofgear meshing noise
speed characteristic
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
High-Speed Camera Analysis
=> Belt touches housing=> Discontinuity of rotation = cause of rattle noise
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EXCITATION IS:
a) Motor and gear orderrelated
b) Rattle noise is non-stationary
SOLUTION STRATEGYCONSEQUENTLY:
1: Optimize belt drive
2: Decoupling of motorand gear againsthousing
3: Increase of housingstiffness
Solution Strategy
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
α
helical gearing
decoupling of motor and gearfrom housing
base
helical gearing
decoupling from housingincrease of stiffness
helical gearingdecoupling from housingincrease of stiffness
EPB Noise Reduction1
2+3
1+2+3
Increase of housingstiffness
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EXCITATION IS:
� Motor and gear orderrelated
b) Rattle noise is non-stationary
SOLUTION STRATEGYCONSEQUENTLY:
1: Optimize belt drive
2: Decoupling of motor andgear against housing
3: Increase of housing stiffness
Solution Strategy
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
EXCITATION IS:
� Motor and gear orderrelated
b) Rattle noise is non-stationary
SOLUTION STRATEGYCONSEQUENTLY:
1: Optimize belt drive
2: Decoupling of motor andgear against housing
3: Increase of housing stiffness
“DoE”
Solution Strategy
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Test
Num
ber
Effe
ct 1
Effe
ct 2
Effe
ct 3
1 1 1 12 1 1 23 2 1 24 2 1 1
Rattle Noise Investigation Using DoE
Subjective ratingRating
Not acceptab le Acceptab le
Index 1 2 3 4 5 6 7 8 9 10
Noise annoying accetab le goodvery
goodexce llent
extrem ly
unp leasent
very
unp leasentunp leasent
clearly
noticab lenoticab le
hard ly
noticab le
hard ly
existing
not
existing
Ger
äusc
h N
r.
Test
pers
on 1
Test
pers
on 2
Test
pers
on 3
Test
pers
on 4
Test
pers
on 5
Test
pers
on 6
Test
pers
on 7
Test
pers
on 8
Test
pers
on 9
Test
pers
on 1
0
1 7 7 6 9 6 6 8 6 8 72 5 4 5 3 4 5 5 5 5 23 4 6 4 4 4 5 7 5 8 44 2 3 4 2 4 3 2 3 5 15 9 9 7 10 7 7 9 7 9 86 3 4 5 3 4 4 5 4 6 3
16
Testplan
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
DoE Result
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Main influences
Main factors:
• torque
• speed
• gear guiding
DoE Result
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
standard motor
stronger motor
Rattle Noise Reduction
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Comparison Before / After
� Reduced motorand gear orderrelated noise
�Reduced rattle noise
This copyrighted document is the property of TRW and is disclosed in confidence. It may not be copied, disclosed to others,or used for manufacturing, without the prior written consent of TRW. ©2006 TRW Automotive Inc.
Summary
EPB noise reduction by combining
- Multi channel sound quality system
- Laser holography
- Noise simulation
- High speed camera
- DoE philosophy and software