Instrumentation and signal processing methods used for machine diagnosticsVSB – Technical University of Ostrava Faculty of Mechanical Engineering Department of Control Systems and Instrumentation
Jiří TůmaMarek Babiuch, Radim Farana, David Fojtík, Petr Kočí, Petr Koňařík, Jiří Kulhánek, Petr Noskievič, Roman Pavlas, Lubomír Smutný, Pavel Smutný, Jaromír Škuta, Antonín Víteček, Miluše Vítečková, Renata Wagnerová
International Carpathian Control Conference ICCC’ 2006Rožnov pod Radhoštěm CZECH REPUBLICMay 29-31, 2006
OutlineSoftware and measurement equipmentsSoftware and signal processing methodsExamples
Angular Vibration MeasurementsExperimental DynamicsMechatronic Systems
Conclusion
Software and measurement equipments for machine diagnostics
Sensors for noise and vibration measurements
Charge amplifier NEXUS Deltatron Accelerometer 4396 & 4508, Triaxial AccelerometerFree-field ½’’ Microphone 4190 Photoelectric Tachometer Probe MM 0024 Exciter 100N (S521) & Power Amplifier 120 VA (A50112)Accelerometer 0.05 Hz 7745A – 1000 Istron EE 0111Delta Tron Impact Hammer 2302-5Force sensor 2311-10 IstronMEDIATOR 2238, Incremental rotary encoders ERN 460-500 and ERN 460-1024ACE Kit with DS 1103 PPC Controller Board
BRÜEL&KJÆR (BK)ENDEVCOHEIDENHEINTIRAdSPACE
Produced by
Signal analyzers / Lasers
9-channel analyzer of the 25,6 kHz frequency range
2-channel analyzer of the 102,4 kHz frequency range
OMETRON Laser vibrometer
angular vibrationlinear vibration
PULSE, the BK Signal Analyzer
SoftwareMatlab-Simulink and ToolboxesdSPACE Support Code Generation PULSE LabShopME’scope VES (Operational Deflection Shapes, Modal Analysis)Indoor software (Signal Analyzer, PULSE Automation Programs)
Test Stands
Mechatronic Lab
Software and signal processing methods developed at the Department of Control Systems and Instrumentation
Signal AnalyzerTime - Filtration in the Frequency Domain, DemodulationFFT - Fast Fourier TransformCPB - Constant Percentage BandAutospectrumCross-SpectrumFRF - Frequency Response FunctionOverall Level AnalysisTachometer for Impulse SignalsResamplingCorrelationFIR FiltersFIR Filter FRFLinear CombinerAutoregressive ModelAutoregressive SpectrumSignal DetrendEigenanalysis
PULSE Automation Program for Phase Demodulation
PULSE Automation Program and Database of Auxiliary Information
Automation program(Visual Basic)
Database client(MS Access)
Measurement software (PULSE)
Data file (MS Access) Data file administration
(MS Access)
Measurement control data
Component data data
Component data Measurement data
Data file definition, information about them
Newly Developed Signal Processing Methods
Methods for phase demodulation based on the Hilbert transform using digital filtersParametric methods for spectral analysis based on autoregressive modelingOrder analysis methodsVold-Kalman order tracking filtering
Vold-Kalman order tracking filtration I
( ) ( ) ( ) ( ) ( )nnxnxtnx εω =−+−∆− 21cos2
Time History : vyfuk_L_mono.wav 2 : Signal
-24000
-16000
-8000
0
8000
16000
24000
0 5 10 15Time [s]
[-]
Vold-Kalman : vyfuk_L_mono.wav 2 : Signal
-24000
-16000
-8000
0
8000
16000
24000
0 5 10 15Time [s]
[-]
2 ord4 ord6 ord8 ord
( ) ( ) ( )nnxny η+=
n = 1,2, …, Ny(n) – measured signalη(n) – error term ω(n) – angular frequencyx(n) – filter output
First generation
Solution( ) yEAAx 1−
+= T2r
Vold-Kalman order tracking filtration IITime History : vyfuk_L_mono.wav 2 : Signal
-24000
-16000
-8000
0
8000
16000
24000
0 5 10 15Time [s]
[-]( ) ( ) ( )( ) ( )nnjnxny η+Θ= exp
Vold-Kalman : vyfuk_L_mono.wav 2 : Signal
0
4000
8000
12000
16000
20000
24000
0 5 10 15Time [s]
Am
pl [-
] 2 ord4 ord6 ord8 ord
n = 1,2, …, Ny(n) – measured signalη(n) – error term ω(n) – angular frequencyx(n) – filter output
Second generation, 2-pole filter
Solution( ) yCEAAx HTr 12 −
+=
( ) ( ) ( ) ( )nnxnxnx ε=−+−− 212
Envelopes
( )( ) ( )( ){ }Njjdiag ΘΘ= exp,...,1expC
Truck Pass-By Noise Measurements
Time History : 3r : Left
-1,5-1,0-0,50,00,51,01,5
0 1 2 3 4 5 6Time [s]
[Pa]
Vold-Kalman : 3r : Left
20304050607080
-10 -5 0 5 10Position [m]
RMS
dB(A
)/ref
2E
-5
[Pa]
27 ord 54 ord 81 ord
3r : Inst Speed
5001000150020002500
0 2 4 6
Time [s]
RPM
Vold-Kalman : 3r : Left
0,970,980,991,001,011,02
-10 0 10Position [m]
c/(c
-v)
RPM c/(c-v)
Angular Vibration Measurements
Using a principle based on the phase demodulation of impulse signals
Phase and Frequency ModulationReal phase modulated
signal
Pω
-1,5-1,0-0,50,00,51,01,5
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1
Revolution
x(t) = A cos(ωPt+∆φM(t))
PhaseModulation signal Sideband
components
Carrying componen
t
Analytic signal
Uniformity of Electric Drill Angular Velocity
-200-100
0100200300
0,0 0,2 0,4 0,6 0,8Nominal Revolution [-]
Ang
ular
vel
ocity
[deg
/s]
LaserEncoder
Laser
Encoder
Gear Angular VibrationTime : Time (Enhanced Time(Encoder))
-0,0016
0,0000
0,0016
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0Nominal Revolution [-]
deg
Time : Time (Time (Enhanced Time(Encoder))) - 0 to 100 ord
-60000-30000
03000060000
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0Nominal Revolution [-]
deg/
s2̂
Time : Order Analyzer : Enhanced Time(Vibrace H)
-10-505
10
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0Nominal Revolution [-]
m/s
^2
Linear acceleration on the gearbox housing
Angular acceleration
Difference between actual and nominal rotation angle
Double differentiation
Instrumentation for Transmission Error (TE) Measurements
4/2 channels PULSEOrder Analysis
&Special software
Heidehain encoders of the ERN 460-500 type
I REV II III IVV
21
44
21
44
E1
E2
Axle
Engine
Car gearbox
Phase Modulation Effect TE Measurement Result
Pinion 21 T
Enhanced Spectrum, 21-Tooth Gear
-90
-70
-50
-30
-10
10
374 416 458 500 542 584 626
Order [-]
RM
S dB
/ref 1
V
Transmission Error
-4-3-2-101234
0 1 2 3
Tooth pitch rotationTE
[mic
ron]
500 RPM, +40 Nm 500 RPM, +80 Nm
Measurements of Car Engine Crankshaft Angular Acceleration
4/2 channels PULSEOrder Analysis
&tacho
crankshaft
camshaft
Impulse signals
(Divider)
Source of Impulse Signals
Angular Acceleration During Two Complete Engine Revolutions
-200
-150
-100
-50
0
50
100
150
200
250
300
0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2
Revolution
rad/s2
4-cylinder / 4-stroke engine4-cylinder / 4-stroke engine
compression cyclescompression cycles
combustion cyclescombustion cycles
-
+
Experimental Dynamics
Vehicle Structure Vibration
Time based Operational Deflection Shapes
Vehicle Structure Vibration
Modal analysis
2 Hz Mode
Vehicle Structure Vibration
Modal analysis
6 Hz Mode
Vehicle Structure Vibration
Modal analysis
9 Hz Mode
Sound Intensity Measurement
Gearbox Noise and Vibration Measurements
Drop Gearbox
Main Gearbox
Semi-unechoicroom at the TATRA Company
Effect of Teeth Surface Modification on Noise Level
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
5386
4330
3408
2740
2203
1771Noise dB
RPM
88-9284-8880-8476-8072-7668-7264-6860-64
Torque Nm
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
3831308024481968154912451001805
Noise dB
RPM
88-9284-8880-8476-8072-7668-7264-6860-64
Torque NmGear train S Gear train T2
S
T1T2
On-road operation Off-road operation
Gear trains of Drop Gearbox
Mechatronic Systems
Multirate Digital Filters for a Stand to Test Rolling Bearings
IIR120 Hz
FIR6410 kHz
2 FIR641k8 Hz
6 FIR64300 Hz
6 FIR6450 Hz
FIR641k8 Hz
FIR64300 Hz
∑ 2ix
∑ 2ix
∑ 2ix
Input
FIR6410 kHz
2
Output 2
Output 1
Snímač vibrací ložiska
Nábojový zesilovač
Frekvenční filtr1,8-10 kHz
Frekvenční filtr300-1800 Hz
Frekvenční filtr 50-300 Hz
Výpočet RMS
Výpočet RMS
Výpočet RMS
Připoslech/Analyzátor
DSP PC
A/D
Amplitudovýfiltr 2
Počet špiček
D/A
44,1 kHz
Antiimagingfiltr
Amplitudovýfiltr 1
Výpočet RPM A/D
44,1 kHz
Tacho
Vibrace
Left
Right
Tachosonda
RS 232
Analog Devices DSP
Test Stand designed by Diagnostika Brno
Functional Block Diagram
Multiratefilters
Inertial measurement unitsPlatform stabilization
LabView
cRIO - Compact Reconfigurable I/O
Analog Devices angular rate sensorADXRS300
Conclusion
The paper reviews instrumentation and software for diagnostics of machines and some of results of research work done for industryEquipments enable to do noise and vibration measurements of machines Special interest is focused at angular vibration during rotationDevelopment of measurement methods is supported by software design