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National Instruments LabVIEW User Manual
Summary of LabVIEW
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Labview tm order analysis toolset user manual labview order analysis toolset user manual august 2003 edition part number 322879b-01.
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Support worldwide technical support and product information ni.Com national instruments corporate headquarters 11500 north mopac expressway austin, texas 78759-3504 usa tel: 512 683 0100 worldwide offices australia 1800 300 800, austria 43 0 662 45 79 90 0, belgium 32 0 2 757 00 20, brazil 55 11 326...
Page 3: Important Information
Important information warranty the media on which you receive national instruments software are warranted not to fail to execute programming instructions, due to defects in materials and workmanship, for a period of 90 days from date of shipment, as evidenced by receipts or other documentation. Nati...
Page 4: Contents
© national instruments corporation v labview order analysis toolset user manual contents about this manual how to use this manual ...............................................................................................Vii conventions ..............................................................
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Contents labview order analysis toolset user manual vi ni.Com chapter 3 gabor transform-based order tracking overview of gabor order analysis............................................................................... 3-1 extracting the order components ..............................................
Page 6: About This Manual
© national instruments corporation vii labview order analysis toolset user manual about this manual this manual provides information about the labview order analysis toolset, including system requirements, installation, and suggestions for getting started with order analysis and the toolset. The man...
Page 7: Related Documentation
About this manual labview order analysis toolset user manual viii ni.Com bold bold text denotes items that you must select or click in the software, such as menu items and dialog box options. Bold text also denotes the names of parameters, dialog boxes, sections of dialog boxes, windows, menus, pale...
Page 8: Introduction to The
© national instruments corporation 1-1 labview order analysis toolset user manual 1 introduction to the labview order analysis toolset this chapter introduces the labview order analysis toolset and the order analysis start-up kit, outlines system requirements, and gives installation instructions. Ov...
Page 9: Machinery
Chapter 1 introduction to the labview order analysis toolset labview order analysis toolset user manual 1-2 ni.Com application is built with components found in the labview order analysis toolset. The order analysis application provides an example of how the labview order analysis toolset can help y...
Page 10: System Requirements
Chapter 1 introduction to the labview order analysis toolset © national instruments corporation 1-3 labview order analysis toolset user manual system requirements you must have labview 6.1 or later full development system or professional development system installed to run the labview order analysis...
Page 11: Example Vis
Chapter 1 introduction to the labview order analysis toolset labview order analysis toolset user manual 1-4 ni.Com example vis if you have experience with order analysis, the example vis, located in the examples\order analysis directory, can help you learn how to use the labview order analysis tools...
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Chapter 1 introduction to the labview order analysis toolset © national instruments corporation 1-5 labview order analysis toolset user manual set to daq and you click the run button on the front panel of the example vi, one of the following vis opens: • acquire data (analog tach) vi • acquire data ...
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Chapter 1 introduction to the labview order analysis toolset labview order analysis toolset user manual 1-6 ni.Com tachometer signal and s&v for the sound or vibration sensor. After choosing data acquisition settings, enter the number of pulses you want the tachometer to generate per revolution in t...
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Chapter 1 introduction to the labview order analysis toolset © national instruments corporation 1-7 labview order analysis toolset user manual figure 1-3. Acquire data with pxi 4472 and tio vi configuration tab use the configuration tab of the acquire data with pxi 4472 and tio vi, shown in figure 1...
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Chapter 1 introduction to the labview order analysis toolset labview order analysis toolset user manual 1-8 ni.Com figure 1-4. Acquire data with pxi 4472 and tio vi acquisition tab the acquisition tab, shown in figure 1-4, allows you to acquire and observe data. Click the acquire button to acquire d...
Page 16: Order Analysis
© national instruments corporation 2-1 labview order analysis toolset user manual 2 order analysis this chapter gives brief descriptions of the need for order analysis, the basic concepts of order analysis, the effect of rotational speed on order identification, and the different order analysis meth...
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Chapter 2 order analysis labview order analysis toolset user manual 2-2 ni.Com vibration signals. The frequency-domain representations of noise and vibration behave as harmonics of the machine rotational speed. In many industries, the harmonics related to the rotational speed are referred to as orde...
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Chapter 2 order analysis © national instruments corporation 2-3 labview order analysis toolset user manual assuming that speed remains constant during data acquisition, you can use the following equations to switch between the frequency domain and the order domain. Orders often reflect the physical ...
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Chapter 2 order analysis labview order analysis toolset user manual 2-4 ni.Com like classical harmonic analysis, order analysis is a powerful tool for gaining a better understanding of the condition of rotating machinery. However, compared to harmonic analysis, order analysis is more effective for t...
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Chapter 2 order analysis © national instruments corporation 2-5 labview order analysis toolset user manual figure 2-3. Pc fan running at constant speed the bottom plot in figure 2-3 depicts the tachometer pulses and the signal from an accelerometer mounted on the pc fan. The plot on the left in figu...
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Chapter 2 order analysis labview order analysis toolset user manual 2-6 ni.Com variable rotational speed in addition to testing rotating machinery running at a constant speed, researchers often perform tests involving run-up and run-down. Like a swept-sine stimulus, testing run-up and run-down provi...
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Chapter 2 order analysis © national instruments corporation 2-7 labview order analysis toolset user manual time, the overall frequency bandwidth, as measured from the conventional power spectrum, is the minimum. Figure 2-5 depicts a signal whose frequency changes as a function of time. Figure 2-5. F...
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Chapter 2 order analysis labview order analysis toolset user manual 2-8 ni.Com harmonics overlap in the conventional power spectrum, you are unable to identify different harmonics by using the conventional power spectrum. Figure 2-6 shows the signal from the same pc fan as the one depicted in figure...
Page 24: Order Analysis Methods
Chapter 2 order analysis © national instruments corporation 2-9 labview order analysis toolset user manual orders overlap, you are unable to derive meaningful information about the individual orders. Harmonic analysis harmonic analysis is suitable for the analysis of rotating machinery only when the...
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Chapter 2 order analysis labview order analysis toolset user manual 2-10 ni.Com currently, the following methods generally are used to perform order analysis: • gabor transform • resampling • adaptive filter the labview order analysis toolset provides the gabor-transform-based method and the resampl...
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Chapter 2 order analysis © national instruments corporation 2-11 labview order analysis toolset user manual figure 2-7. Padding schemes in zero padding, shown in figure 2-7(a), the first window and the last window only cover one data block each. The remaining area in the range of the window is fille...
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Chapter 2 order analysis labview order analysis toolset user manual 2-12 ni.Com figure 2-8 shows two examples of padding. Figure 2-8. Padding examples refer to appendix a, gabor expansion and gabor transform , for more information about the gabor transform and the gabor expansion. Refer to chapter 3...
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Chapter 2 order analysis © national instruments corporation 2-13 labview order analysis toolset user manual resampling resampling is a widely used method of order analysis. Figure 2-9 illustrates the resampling method. Figure 2-9. Resampling in the resampling method, time-samples are converted to an...
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Chapter 2 order analysis labview order analysis toolset user manual 2-14 ni.Com after acquiring angle samples with either hardware or software, you can perform a fourier transform on the angle samples to analyze them. Because the time domain has changed into the angle domain, the frequency domain no...
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Chapter 2 order analysis © national instruments corporation 2-15 labview order analysis toolset user manual after the resampling process takes place, recovering a time waveform at a specific order might be difficult. Refer to chapter 4, resampling-based order analysis , for information about how the...
Page 31: Gabor Transform-Based Order
© national instruments corporation 3-1 labview order analysis toolset user manual 3 gabor transform-based order tracking this chapter discusses a new order analysis method based on the gabor transform and provided by the labview order analysis toolset that enables you to complete the following tasks...
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Chapter 3 gabor transform-based order tracking labview order analysis toolset user manual 3-2 ni.Com in figure 3-1, the magnitudes of coefficients are shown as gray scale, with full white indicating a maximal magnitude and full black indicating a minimal magnitude. Because the rotational speed chang...
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Chapter 3 gabor transform-based order tracking © national instruments corporation 3-3 labview order analysis toolset user manual complete the following steps to perform gabor order analysis. 1. Acquire data samples from the tachometer and noise or vibration sensors synchronously at some constant sam...
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Chapter 3 gabor transform-based order tracking labview order analysis toolset user manual 3-4 ni.Com processed by a gabor transform, the index of the n th order is given by the following equation. , where rpm is the averaged instantaneous rotational speed in the time interval, n is the number of fre...
Page 35: Masking
Chapter 3 gabor transform-based order tracking © national instruments corporation 3-5 labview order analysis toolset user manual figure 3-3(b) illustrates constant order bandwidth. The neighborhood is considered as the region between and . While the frequency bandwidth varies in time, the order band...
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Chapter 3 gabor transform-based order tracking labview order analysis toolset user manual 3-6 ni.Com vi to perform the mask operation. Refer to the labview order analysis toolset help for information about the template to mask vi. You can consider the mask operation a time-variant bandpass filter in...
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Chapter 3 gabor transform-based order tracking © national instruments corporation 3-7 labview order analysis toolset user manual figure 3-4(b) shows a mask array around the fourth order with a constant frequency bandwidth. The true values comprise the white area, while the false values comprise the ...
Page 38: Displaying Spectral Maps
Chapter 3 gabor transform-based order tracking labview order analysis toolset user manual 3-8 ni.Com time-variant filters. Figure 3-6 shows an original signal and the spectrum of the reconstructed signal. Figure 3-6. Spectrum of reconstructed signal in figure 3-6, one row is selected from the joint ...
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Chapter 3 gabor transform-based order tracking © national instruments corporation 3-9 labview order analysis toolset user manual figure 3-7. 2d spectral maps figure 3-7(a) is the frequency-time spectral map generated directly from the gabor coefficients. The magnitudes of coefficients are shown as g...
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Chapter 3 gabor transform-based order tracking labview order analysis toolset user manual 3-10 ni.Com figure 3-7(c) shows the frequency-rpm spectral map. The horizontal axis represents rpm, or rotational speed. You can map the rpm axis from the time axis in the frequency-time spectral map by the rpm...
Page 41: Resampling-Based Order
© national instruments corporation 4-1 labview order analysis toolset user manual 4 resampling-based order analysis this chapter describes the resampling method provided by the labview order analysis toolset, determining the time instance for resampling, resampling vibration data, and slow roll comp...
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Chapter 4 resampling-based order analysis labview order analysis toolset user manual 4-2 ni.Com complete the following steps to perform resampling-based order analysis. 1. Acquire data samples from tachometer and noise or vibration sensors synchronously at some constant sample rate. 2. Use the labvi...
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Chapter 4 resampling-based order analysis © national instruments corporation 4-3 labview order analysis toolset user manual a larger margin of samples for analysis and need to resample 2.5 k samples in one revolution. Most of the time, a tachometer does not produce enough pulses in one revolution. T...
Page 44: Resampling Vibration Data
Chapter 4 resampling-based order analysis labview order analysis toolset user manual 4-4 ni.Com figure 4-2. Original time sequence and cic interpolation filter with an interpolation factor of eight resampling vibration data the resampling operation converts a vibration signal from the time domain in...
Page 45: Slow Roll Compensation
Chapter 4 resampling-based order analysis © national instruments corporation 4-5 labview order analysis toolset user manual according to the nyquist sampling theorem, you can exactly reconstruct the time signal x ( t ) from samples x ( nt s ) with the following equation. (4-1) where h s is a sinc fu...
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Chapter 4 resampling-based order analysis labview order analysis toolset user manual 4-6 ni.Com when monitoring shaft vibration with a proximity probe, the acquired signal contains not only the vibration of the shaft but also the shaft runout, such as a nonconcentric shaft condition at the probe mea...
Page 47: Calculating Rotational Speed
© national instruments corporation 5-1 labview order analysis toolset user manual 5 calculating rotational speed this chapter describes the digital differentiator method used by the labview order analysis toolset to calculate rotational speed and describes averaging pulses to smooth noisy calculated...
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Chapter 5 calculating rotational speed labview order analysis toolset user manual 5-2 ni.Com figure 5-1. Tachometer signal and rotation angle the arrival time t k of the pulses p ( k ) in the tachometer signal correspond to the cumulative rotation angle θ ( t k ). The cumulative rotation angle funct...
Page 49: Averaging Pulses
Chapter 5 calculating rotational speed © national instruments corporation 5-3 labview order analysis toolset user manual of an equally spaced sequence requires fewer computations than calculating the first derivative of an unequally spaced sequence. For the evenly separated function series t k , you...
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Chapter 5 calculating rotational speed labview order analysis toolset user manual 5-4 ni.Com figure 5-2 shows an example of the rotational speed calculated from the tachometer pulses. Figure 5-2. Cumulative revolution and rotational speed in figure 5-2, the dotted line represents the results of calc...
Page 51: Gabor Expansion and
© national instruments corporation a-1 labview order analysis toolset user manual a gabor expansion and gabor transform this appendix presents an overview of the gabor expansion and the gabor transform methods used in the labview order analysis toolset. This appendix also describes application issue...
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Appendix a gabor expansion and gabor transform labview order analysis toolset user manual a-2 ni.Com the sampled stft is also known as the gabor transform and is represented by the following equation. (a-2) where ∆ m represents the time sampling interval and n represents the total number of frequenc...
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Appendix a gabor expansion and gabor transform © national instruments corporation a-3 labview order analysis toolset user manual corresponding dual window function from ∆ m independent linear systems with the following equation. (a-4) where l denotes the window length. Denotes a periodic auxiliary f...
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Appendix a gabor expansion and gabor transform labview order analysis toolset user manual a-4 ni.Com discrete gabor-expansion-based time-varying filter initially, discrete gabor expansion seems to provide a feasible method for converting an arbitrary signal from the time domain into the joint time-f...
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Appendix a gabor expansion and gabor transform © national instruments corporation a-5 labview order analysis toolset user manual 4. Compute the new gabor coefficients after you obtain the time waveform. 5. Repeat steps 1 through 4 until the time waveforms converge. Without a loss of generality, rewr...
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Appendix a gabor expansion and gabor transform labview order analysis toolset user manual a-6 ni.Com c k and converge. With . For with , the support of c k in the time-frequency domain is inside the masked area if and only if the following equation is true. (a-6) for 0 ≤ k n and 0 ≤ m . Two trivial ...
Page 57: References
© national instruments corporation b-1 labview order analysis toolset user manual b references this appendix lists the reference material used for the labview order analysis toolset. • albright, michael, and shie qian. Comparison of the new proposed gabor order tracking technique vs. Other order tra...
Page 58: Technical Support and
© national instruments corporation c-1 labview order analysis toolset user manual c technical support and professional services visit the following sections of the national instruments web site at ni.Com for technical support and professional services: • support —online technical support resources i...
Page 59: Glossary
© national instruments corporation g-1 labview order analysis toolset user manual glossary numbers/symbols infinity. 2d two-dimensional. A adaptive filter a type of filter that operates on a recursive algorithm to achieve the goal of optimum. It is self-designing and suitable for tracking time varia...
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Glossary labview order analysis toolset user manual g-2 ni.Com f fft fast fourier transform. Fundamental component portion of a signal whose frequency is at the fundamental frequency. G gabor coefficient the result of gabor transform. Gabor expansion the inverse gabor transform used on gabor coeffic...
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Glossary © national instruments corporation g-3 labview order analysis toolset user manual order curves the high power density curves in a spectral map which indicate order components. Orthogonal-like gabor transform pair the pair is composed of a gabor transform and a gabor expansion when the gabor...
Page 62: Index
© national instruments corporation i-1 labview order analysis toolset user manual index a adaptive filter, 2-15 analysis of rotating machinery, using the toolset, 1-2 applying an iteration to reconstruct a time waveform, a-4 c calculating rotational speed, 5-1 averaging pulses, 5-3 digital different...
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Index labview order analysis toolset user manual i-2 ni.Com k knowledgebase, c-1 m masking, 3-5 extracting orders, 3-6 reconstructing a signal, 3-7 n national instruments customer education, c-1 professional services, c-1 system integration services, c-1 technical support, c-1 worldwide offices, c-1...