Documentation

Vibration Post-Processing Module

vibEngine.framework© for iOS®/iPadOS®

Version: 1.02
Author: David Bukowitz

Created: 11 Jun, 2021
Update: 16 Nov, 2021

If you have any questions that are beyond the scope of this help file, Please feel free to email via info@rotovibes.com

Description

vibEngine© framework is an iOS®/iPadOS® library that contains experienced methods for vibration analysis. The framework includes modules for data post-processing, vibration evaluation, etc. with the following functionalities:

Time-Domain Filtering

Fast-Fourier Transform

Frequency-Domain integration

Windowing functions

DC Removal Filter

Time-Domain Overall Calculation

Frequency-Domain Overall Calculation

Frequecny Bands Overall Calculation

Time-Domain Higher Peaks

Frequency-Domain Higher Peaks

Rotor speed estimator

Bearing Damage Indicator

Fault Frequency Damage Indicator

Frequency-Domain Cross-Phase Calculation

FRF Calculations

Vibration Evaluation based on Industrial Standards, etc

Installation

Follow the steps below to install the vibeAV.framework

Drag and drop the vibeAV.framework file into your Xcode project

Select the "Embed & Sign" option in the Framworks, Libraries and Embedded Content menu

Framework Anatomy

Signal Post-Processing Module (vibePostProc module)


...

//Time-Domain Overall
+(double)timeDomainOverall:(NSArray*)signalArray withSize:(NSInteger)dataSize;
   
//Time-Domain Max Peak
+(double)timeDomainPeak:(NSArray*)signalArray withSize:(NSInteger)dataSize;
  
//Crest-Factor
+(double)crestFactor:(NSArray*)signalArray withSize:(NSInteger)dataSize;
  
//Frequency-Domain Overall
+(double)frequencyDomainOverall:(NSArray*)spectrumArray withSize:(NSInteger)spectrumSize;
                
//Frequency-Domain Overall (bins)
+(double)frequencyDomainBandOverall:(NSArray*)spectrumArray startFreqBin:(int)startBin endFreqBin:(int)endBin;
                
//Frequency-Domain Overall (Hz)
+(double)frequencyHzDomainBandOverall:(NSArray*)spectrumArray withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples startFreq:(int)startFreq endFreq:(int)endFreq;
                
//FFT for Acceleration raw data
//integrationType: 0->Acceleration, 1->Velocity, 2->Displacement
+(NSArray*)fft_calc:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples integrationType: (int)integrationType;
                
//Frequency-Domain Windowing
//windowType: 0->None, 1->Hanning, 2->Hamming, 3->Blackman, 4->Nutall, 5->Flat-Top
+(NSArray*)spectrumWindowing:(NSArray*)spectrumArray withSize:(NSInteger)spectrumSize withType:(int)windowType;
                
//Time-Domain Filters
//filterType: 0->None, 1->Low-Pass, 2->High-Pass
+(NSArray*)filteredSignal:(NSArray*)signalArray withSize:(NSInteger)dataSize withType:(int)filterType;
                
//Time-Domain DC-removal
+(NSArray*)dcRemoval:(NSArray*)signalArray withSize:(NSInteger)dataSize;
                
//Overall Velocity from Acceleration raw data
//unitsMetric: true->Metric (mm/s), false->Imperial (ips)
//isRms: true->rms, false->peak
+(double)overallVelocityFromAccTWF:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples unitsMetric:(bool)isMetric isRms:(bool)isRms;
                
//Overall Displacement from Acceleration raw data
//unitsMetric: true->Metric (microns), false->Imperial (mils)
//isRms: true->rms, false->peak
+(double)overallDisplacementFromAccTWF:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples unitsMetric:(bool)isMetric isRms:(bool)isRms;
                
//Running-Speed (RS) estimator (RPM)
+(double)rsEstimator:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples;

//Bearing Damage Indicator 0-10
+(int)bd_indicator:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples;

//Fault Frequency Damage Indicator 0-10
+(int)ff_indicator:(NSArray*)rawData withSamplingRate:(int)sampRate withNumberOfSamples:(int)numSamples withDiscreteFreqHz:(double)fault_freq withAccThreshold:(double)accLimit withVelThreshold:(double)velLimit;

...

In your project import vibEngine/vibePostProc.h and use as follow:


#import "vibEngine/vibePostProc.h"
...

// **** Time-Domain Filtering Sample ****
//filterType = 0 -> no filter
//filterType = 1 -> low pass-band filter
//filterType = 2 -> high pass-band filter

filteredSignalArray = [vibePostProc filteredSignal:signalArray withSize:dataSize withType:filterType];

...

Vibration Evaluation Standards (vibeStds module)


...

//-------------------------------------------------------------
//ISO-10816-3/20816 condition evaluation for velocity vibration
//measurement of non-rotating parts
//-------------------------------------------------------------
// group: 1, 2, 3, 4 per ISO specs
// isFlexible: true->flexible foundation, false->rigid foundation
// isMetric: true->mm/s, false->ips
// returns: A->Newly commisioned machines
//          B->Acceptable for unrestricted long-term operation
//          C->Unsatisfactory for long-term continuous operation
//          D->Sufficient severity to cause damage to the machine

+(NSString*)iso10816conditionWithVelocityVibration:(double)vibrationValue withMachineGroup:(int)group isFoundationFlexible:(bool)isFlexible isUnitsMetric:(bool)isMetric;


//-----------------------------------------------------------------
//ISO-10816-3/20816 condition evaluation for displacement vibration
//measurement of non-rotating parts
//-----------------------------------------------------------------
// group: 1, 2, 3, 4 per ISO specs
// isFlexible: true->flexible foundation, false->rigid foundation
// isMetric: true->microns, false->mils
// returns: A->Newly commisioned machines
//          B->Acceptable for unrestricted long-term operation
//          C->Unsatisfactory for long-term continuous operation
//          D->Sufficient severity to cause damage to the machine

+(NSString*)iso10816conditionWithDisplacementVibration:(double)vibrationValue withMachineGroup:(int)group isFoundationFlexible:(bool)isFlexible isUnitsMetric:(bool)isMetric;


//---------------------------------------------------------
//ISO-10816-3/20816 allowable values for velocity vibration
//measurement of non-rotating parts
//---------------------------------------------------------
// group: 1, 2, 3, 4 per ISO specs
// isFlexible: true->flexible foundation, false->rigid foundation
// isMetric: true->mm/s, false->ips
// returns an array with in the form [alert,danger]

+(NSArray*)iso10816allowableVibrationWithGroup:(int)group isFoundationFlexible:(bool)isFlexible isUnitsMetric:(bool)isMetric;


//-------------------------------------------------------------
//ISO-10816-3/20816 allowable values for displacement vibration
//measurement of non-rotating parts
//-------------------------------------------------------------
// group: 1, 2, 3, 4 per ISO specs
// isFlexible: true->flexible foundation, false->rigid foundation
// isMetric: true->microns, false->mils
// returns an array with in the form [alert,danger]

+(NSArray*)iso10816allowableVibrationDispWithGroup:(int)group isFoundationFlexible:(bool)isFlexible isUnitsMetric:(bool)isMetric;


//------------------------------------------------------------------
//ANSI/HI 9.6.4 Std allowable vibration values for Rotodynamic Pumps
//------------------------------------------------------------------
// pumpPowerBHP: machines BHP
// isVsPump: true->pumps type VS1, VS2, VS3, VS4, VS5, VS6, VS7, VS8;
//           false->pumps type BB1, BB2, BB3, BB4, BB5, OH1, OH2, OH3, OH4, OH5, OH7
// isMetric: true->mm/s, false->ips
// returns: allowable velocity vibration value

+(double)ansiHI964AllowableWithMachineBHP:(double)pumpPowerBHP isVsPump:(bool)isVsPump isUnitsMetric:(bool)isMetric;


//-----------------------------------------------------------------------
//ISO/TR 17243-1 Std allowable vibration values for Machine Tool Spindles
//-----------------------------------------------------------------------
// ratedPower: machines rated power in kW
// speedRPM: machine rpm
// isRollerBearing: true->Roller Bearing (line Contact), false->Ball Bearing (point vontact)
// isLTSC: true->Long Term Spindle Condition (vel) false->Short Term Spindle Condition (acc)
// isMetric: true->mm/s, false->ips
// returns an array with the theesholds in the form [alert,danger]

+(NSArray*)iso_tr_17243_allowableVibrationWithPower:(double)ratedPower speedRPM:(int)rpm isRollerBearing:(bool)isRollerBearing isLTSC:(bool)isLongTermCondition isMetric:(bool)isUnitsMetric;


//------------------------------------------------------------
//NEMA MG-1 Std allowable vibration values for Electric Motors
//------------------------------------------------------------
// speedRPM: machines rpm
// isMetric: true->mm/s, false->ips
// returns: allowable velocity vibration value

+(double)nema_mg1_allowableVibrationWithRpm:(int)speedRpm isUnitsMetric:(bool)isMetric;

...

In your project import vibEngine/vibeStds.h and use as follow:


#import "vibEngine/vibeStds.h"
...

//sample using 0.15 ips velocity reading with a flexible foundation group 2 machine

double vibrationVelocity = 0.15; //ips

NSString *condition = [vibeStds iso10816conditionWithVelocityVibration:vibrationVelocity withMachineGroup:2 isFoundationFlexible:true isUnitsMetric:false];

NSLog(@"machine condition: %@", condition);
...

For this sample the response in the console log will show:

An example to calculate the allowable vibration value for pumps based on ANSI/HI 9.6.4 is shown below:


#import "vibEngine/vibeStds.h"
...
//sample for horizontal rotodynamic pump with 50 BHP
double allowableValue = [vibeStds ansiHI964AllowableWithMachineBHP:50 isVerticalPump:false isUnitsMetric:false];
NSLog(@"allowable velocity value in ips: %.2f", allowableValue);
...

For this sample the console log will display:

Changelog

See what's new added, changed, fixed, improved or updated in the latest versions.

Version 1.02 (16 Nov, 2021)

Updated Vibration standards updated

Version 1.01 (29 Oct, 2021)

Updated Optimized for iOS®15