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