Unit 44 Vibrationdata Sine Filtering.

Slides:

Advertisements

Similar presentations

Vibrationdata 1 Unit 10 Sample Rate, Nyquist Frequency & Aliasing.

Advertisements

Unit 3 Vibrationdata Sine Sweep Vibration.

1 Sine Vibration Vibrationdata Unit 2. 2 Vibrationdata Sine Amplitude Metrics.

Vibrationdata AMERICAN INSTITUTE OF AERONAUTICS AND ASTRONAUTICS 1 A Time Domain, Curve-Fitting Method for Accelerometer Data Analysis By Tom Irvine.

Vibrationdata 1 Unit 7 Fast Fourier Transform (FFT)

Unit 41 PSD Special Topics Vibrationdata Band-Splitting

Sampling and quantization Seminary 2. Problem 2.1 Typical errors in reconstruction: Leaking and aliasing We have a transmission system with f s =8 kHz.

Vibrationdata 1 Unit 4 Random Vibration. Vibrationdata 2 Random Vibration Examples n Turbulent airflow passing over an aircraft wing n Oncoming turbulent.

Vibrationdata 1 Non-Gaussian Random Fatigue and Peak Response Unit 36.

Techniques in Signal and Data Processing CSC 508 Fourier Analysis.

NESC Academy 1 Unit 27 SRS Synthesis 1. Wavelets 2. Damped Sinusoids.

Circuit Board Fatigue Response to Random Vibration Part 2

Sine-on-Random Vibration

Integration and Differentiation of Time Histories

Vibrationdata 1 SDOF Response to Power Spectral Density Base Input Unit 13.

Inputs to Signal Generation.vi: -Initial Distance (m) -Velocity (m/s) -Chirp Duration (s) -Sampling Info (Sampling Frequency, Window Size) -Original Signal.

Leakage & Hanning Windows

Vibrationdata 1 Unit 5 The Fourier Transform. Vibrationdata 2 Courtesy of Professor Alan M. Nathan, University of Illinois at Urbana-Champaign.

Vibrationdata 1 Unit 19 Digital Filtering (plus some seismology)

Power Spectral Density Function

Vibrationdata 1 Unit 17 SDOF Response to Applied Force Revision A.

Illustrative Examples, Two Different Machine Data.

Vibrationdata 1 Unit 15 SDOF Response to Base Input in the Frequency Domain.

Periodogram of a sinusoid + spike Single high value is sum of sine curves all in phase at time t 0 :

Vibrationdata 1 Unit 5 The Fourier Transform. Vibrationdata 2 Courtesy of Professor Alan M. Nathan, University of Illinois at Urbana-Champaign.

Vibrationdata 1 Unit 9 White Noise FFT. Vibrationdata 2 Fourier Transform, Sine Function A Fourier transform will give the exact magnitude and frequency.

Unit 14 Synthesizing a Time History to Satisfy a Power Spectral Density using Random Vibration.

Using Fatigue to Compare Sine and Random Environments

LPC-analysis-VOSIM-resynthesis Combined class December 18 th 2012 Johan & Peter Institute of Sonology Royal Conservatory, The Hague.

Vibrationdata 1 Unit 15 SDOF Response to Base Input in the Frequency Domain.

Vibrationdata 1 Unit 6a The Fourier Transform. Vibrationdata 2 Courtesy of Professor Alan M. Nathan, University of Illinois at Urbana-Champaign.

1 1 bd Systems, Inc. Advanced Technology Division Waveform Reconstruction via Wavelets October 2005 Revision B bd Systems, Inc. Advanced Technology Division.

Power Spectral Density Functions of Measured Data

Vibrationdata Synthesizing a Time History to Satisfy a Power Spectral Density using Random Vibration Unit 14 1.

Vibrationdata 1 Power Spectral Density Function PSD Unit 11.

Vibrationdata 1 Unit 18 Force Vibration Response Spectrum.

A NOVEL SIGNAL PROCESSING METHOD BASED ON THE FREQUENCY MODALITY FOR INTRA-BODY MEDICAL INSTRUMENT TRACKING Dr. DIMITRIS A. FOTIADIS TECHNOLOGICAL EDUCATIONAL.

Force Vibration Response Spectrum

Biomathematics seminar Application of Fourier to Bioinformatics Girolamo Giudice.

Unit 9 White Noise FFT.

CS 591 S1 – Computational Audio -- Spring, 2017

National Mathematics Day

(plus some seismology)

Unit 3 Vibrationdata Sine Sweep Vibration.

SDOF Response to Applied Force Revision A

Sassan Tabatabaei, Freddy Ben-Zeev and Michael Lee

Sassan Tabatabaei, Freddy Ben-Zeev and Michael Lee

Unit 5 The Fourier Transform.

Fast Fourier Transform (FFT)

Fast Fourier Transform (FFT)

1 Vocoders. 2 The Channel Vocoder (analyzer) : The channel vocoder employs a bank of bandpass filters,  Each having a bandwidth between 100 HZ and 300.

Fundamentals Data.

Data Analysis in Particle Physics

Fast Fourier Transform (FFT)

Lab 1: (i) TIMS introduction (ii) Modeling an Equation

Universitas Islam Indonesia

Sound & Sound Waves.

SLOPE: A MATLAB Revival

Net 222: Communications and networks fundamentals (Practical Part)

Measured Period VOICE SIGNAL

Any type of vibration can be defined by

Hanning and Rectangular Windows

Lecture 2: Frequency & Time Domains presented by David Shires

Leakage Error in Fourier Transforms

(plus some seismology)

8.6 Autocorrelation instrument, mathematical definition, and properties autocorrelation and Fourier transforms cosine and sine waves sum of cosines Johnson.

Uses of filters To remove unwanted components in a signal

Introduction: How to use Audacity to generate and analyze a signal.

Unit 2 Vibrationdata Sine Vibration.

Presentation transcript:

Unit 44 Vibrationdata Sine Filtering

Introduction Vibrationdata We have covered time-domain, sine curve-fitting in previous units for signal identification This unit will use this method for a new purpose, to separate sine and random components of a signal The curve-fitting is done using random number generation and trial-and- error, with some convergence built-in A measured sine vibration typically has some slight variation in amplitude and frequency, thus require a few sinusoids to match the data The following method works best for “short “ time segments Could be used to remove 60 Hz noise from measured data

Vibrationdata Exercise 1 Generate white noise Add sine component Then separate sine and random components

Vibrationdata Save as: white

Displacement Vibrationdata

Displacement Vibrationdata Save as: combined

Sine-on-Random Signal Vibrationdata

Sine-on-Random Histogram Vibrationdata

Vibrationdata Displacement Time History > Filters, Various > Remove Sine Tones

Vibrationdata Comparison Results Case Amplitude fn(Hz) Phase(rad) 1 1.0169 99.9989 0.0471 Standard Deviations original: 1.232 synthesis: 0.7191 residual: 1

Comparison, Close-up Vibrationdata

Original minus Sine Synthesis Vibrationdata

Vibrationdata Exercise 2 Bombardier Q400 Turboprop Acoustics The PW150A engine/propeller rotation rate during takeoff and climb is 1020 RPM, but is throttled back at cruise altitude to 850 RPM, or 14.17 Hz There are six blades on each engine, so the blade passing frequency is 85 Hz

Displacement Vibrationdata Read in file: Q400

Vibrationdata

Vibrationdata Spectral Peaks Next step: Separate blade passing frequencies from background noise

Displacement Vibrationdata

Vibrationdata Results for 85 Hz Component Results Case Amplitude fn(Hz) Phase(rad) 1 0.4765 85.0661 4.5830 2 0.1591 85.1877 1.7794 3 0.1311 85.0024 1.1945 4 0.0601 84.8849 0.9296 5 0.0541 85.3313 4.5783 6 0.0328 85.5232 5.4033 7 0.0269 85.1293 4.7223 8 0.0264 85.8288 3.8821 9 0.0249 84.7275 4.0180 10 0.0188 84.4948 0.4494 Diminishing returns effect as additional cases are included for a given frequency

Vibrationdata Comparison Difference is due to background noise and some spectral components unrelated to blade passing frequency

Original minus Synthesis Vibrationdata

Vibrationdata Residual FFT Peak at 354.2 Hz is unrelated to blade passing frequency Could repeat exercise with more aggressive sine removal