Case Study: Window Regulator Assembly Line
Hankinson Inc.
Julian Hankinson
www.hankinsoninc.com
Performance & NVH Test Station
Accelerometer Actuators
Rail Bracket Motor
Example Data & Test Criteria
Rail Vibration Data for Cable Grinding Issue
1.4 1.45 1.5 1.55 1.61
0
1
0
1
0
1
Time [sec]
Acce
l [G
]
Cable Pass Period
Cable Pass Period
Good Unit
Moderate Cable Grinding
Severe Cable Grinding
Rail Vibration Spectrums
0 200 400 600 800 10000
0.01
0.02
0.03
0.04
0.05
Frequency [Hz]
G r
ms
Cable GrindingNo Cable Grinding
Band of ConsistentDifference
Filtered & Enveloped Rail Vibration Data
1.4 1.45 1.5 1.55 1.61
0
1
0
1
0
1
Time [sec]
Acce
l [G
]
Cable Pass Period
Cable Pass Period
Good Unit
Moderate Cable Grinding
Severe Cable Grinding
Spectrums of Enveloped Data
0 50 100 150 2000
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
Frequency [Hz]
G r
ms
Good UnitModerate Cable GrindingSevere Cable Grinding
Cable Coil Pass Frequency
Statistical Analysis of Envelope Criteria
for Cable Grinding Issue
0 0.02 0.04 0.060
10
20
30
40
50
Envelope Magnitude @ Cable Pass Frequency
Nu
mb
er
of U
nits
"Good" Units ( 3 )"Bad" Units
Moderate Cable Grinding
Severe CableGrinding
Statistical Analysis of Kurtosis Criteria
for Cable Grinding Issue
2 3 4 5 60
20
40
60
80
100
120
140
Kurtosis
Nu
mb
er
of U
nits
"Good" Units ( 3 )"Bad" Units
Acoustic Spectrum Comparison
for Motor Noise Issue
0 1000 2000 3000 4000 50000
0.5
1
Vo
lts p
ea
k
0 1000 2000 3000 4000 50000
0.5
1
Frequency [Hz]
Vo
lts p
ea
k
Quiet Motor
Loud Motor High FrequencyContent
Statistical Analysis of High Frequency
Energy Band Criteria for Motor Noise Issue
0 0.1 0.2 0.3 0.4 0.5 0.60
20
40
60
80
100
Frequency Band Energy, Motor Microphone
Nu
mb
er
of U
nits
"Good" Units ( 3 )"Bad" Units