Maintenance is a set of organised activities that are carried out in order to keep an item in its best
operational condition with minimum cost acquired. Predictive maintenance (PdM) is one of the maintenance
program that recommends maintenance decisions based on the information collected through condition
monitoring techniques, statistical process control or equipment performance for the purpose of early detection
and elimination of equipment defects that could lead to unplanned downtime of machinery or unnecessary
expenditures. Particularly Gears and rolling element bearings are critical elements in rotating machinery, so
predictive maintenance is often applied to them. Fault signals of gearboxes or rolling-element bearings are nonstationary.
This paper concludes with a brief discussion on current practices of PDM methodologies such as
vibration analysis and Acoustic Emission analysis, which are widely used as they offers a complimentary tool
for health monitoring or assessment of gears in rotating machineries
This presentation discusses condition monitoring strategies from failures-based to predictive maintenance. It covers predictive maintenance techniques like vibration analysis, wear debris monitoring, and thermography. Vibration parameters like amplitude, frequency, and phase are explained. Common machine faults identified by vibrations are listed. Advanced vibration analysis techniques like phase analysis, Bode plots, and orbit analysis are introduced. Wear debris analysis helps predict internal machine condition by studying worn particles. Thermography uses infrared cameras to detect equipment temperature variations indicative of potential issues.
Detection of Gear Fault Using Vibration AnalysisIJRES Journal
This document presents a study on detecting gear faults in a gearbox using vibration analysis and motor current signature analysis. The experimental setup consists of a gearbox coupled to an induction motor. Vibration data is collected from the gearbox using an accelerometer under different load conditions and gear operations. Motor current is also measured using current probes. The results show that vibration parameters and motor current values change with the introduction of gear faults like removed teeth. The analysis of motor current signatures provides a non-intrusive way to monitor the condition of an inaccessible gearbox by detecting faults that cause modulations in the current waveform.
This presentation is equipped with the basic concepts of Condition Monitoring. The methods and analysis, circumscribed by Condition Monitoring, are summarized with an addition of application in this presentation.
Gearbox Noise & Vibration Prediction and ControlIRJET Journal
This document discusses techniques for reducing noise and vibration in gearboxes. It begins by reviewing common sources of gearbox noise like transmission error between gear teeth and vibration transferred to surrounding structures. Next, it examines factors that influence gear noise like torque, speed, and tooth design properties. Methods for analyzing noise like determining transmission error and time-varying gear mesh stiffness are presented. The goal is to minimize excitations from meshing gears that cause vibration of the gearbox casing and radiate noise.
Condition Monitoring of Rotating Equipment Considering the Cause and Effects ...IJMERJOURNAL
This document summarizes research on condition monitoring of rotating equipment using vibration analysis. It discusses various signal processing techniques used for fault detection and diagnosis, including time-domain analysis, frequency domain analysis, time-frequency analysis using wavelet transforms, and support vector machines. It also reviews literature on prognostics approaches that use condition data to predict failures through artificial intelligence techniques. The document aims to provide an overview of recent developments in diagnostic and prognostic models, algorithms, and technologies for processing sensor data from condition monitoring systems.
The document discusses various aspects of condition monitoring through vibration analysis. It defines condition monitoring and different types of maintenance. It explains why condition monitoring is important and some key physical parameters that are measured. It then focuses on condition monitoring through vibration analysis, discussing concepts like amplitude, frequency, causes of vibration, and analyzing case studies of different machines. Key points covered include vibration measurement and analysis, identifying issues like unbalance, misalignment, looseness and bearing defects.
This document discusses various methods of condition monitoring for machines, including vibration monitoring, lubricant analysis, acoustic emission, infrared thermography, and ultrasound emission. Vibration monitoring uses accelerometers to detect vibrations which can indicate developing faults. Lubricant analysis examines oil properties, contaminants, and wear debris to monitor machine health. Acoustic emission detects elastic waves from structural changes to identify cracks. Infrared thermography uses thermal cameras to detect temperature variations that may indicate issues. Ultrasound emission employs transducers that use the piezoelectric effect to generate and detect ultrasound waves for non-destructive testing of materials.
Condition monitoring of rotating machines pptRohit Kaushik
This document discusses condition monitoring of rotating machines. It covers various techniques for monitoring parameters like temperature, vibration, electrical signals and fluxes to detect faults in machines like motors and generators. Local temperature can be monitored using devices embedded in the insulation near hot parts like the winding or core. Vibration is commonly monitored at various frequencies to analyze faults in components. Electrical signals like current and flux are also monitored to detect issues in windings or rotors. Overall, condition monitoring aims to continuously evaluate equipment health and detect early-stage faults in machines.
This presentation discusses condition monitoring strategies from failures-based to predictive maintenance. It covers predictive maintenance techniques like vibration analysis, wear debris monitoring, and thermography. Vibration parameters like amplitude, frequency, and phase are explained. Common machine faults identified by vibrations are listed. Advanced vibration analysis techniques like phase analysis, Bode plots, and orbit analysis are introduced. Wear debris analysis helps predict internal machine condition by studying worn particles. Thermography uses infrared cameras to detect equipment temperature variations indicative of potential issues.
Detection of Gear Fault Using Vibration AnalysisIJRES Journal
This document presents a study on detecting gear faults in a gearbox using vibration analysis and motor current signature analysis. The experimental setup consists of a gearbox coupled to an induction motor. Vibration data is collected from the gearbox using an accelerometer under different load conditions and gear operations. Motor current is also measured using current probes. The results show that vibration parameters and motor current values change with the introduction of gear faults like removed teeth. The analysis of motor current signatures provides a non-intrusive way to monitor the condition of an inaccessible gearbox by detecting faults that cause modulations in the current waveform.
This presentation is equipped with the basic concepts of Condition Monitoring. The methods and analysis, circumscribed by Condition Monitoring, are summarized with an addition of application in this presentation.
Gearbox Noise & Vibration Prediction and ControlIRJET Journal
This document discusses techniques for reducing noise and vibration in gearboxes. It begins by reviewing common sources of gearbox noise like transmission error between gear teeth and vibration transferred to surrounding structures. Next, it examines factors that influence gear noise like torque, speed, and tooth design properties. Methods for analyzing noise like determining transmission error and time-varying gear mesh stiffness are presented. The goal is to minimize excitations from meshing gears that cause vibration of the gearbox casing and radiate noise.
Condition Monitoring of Rotating Equipment Considering the Cause and Effects ...IJMERJOURNAL
This document summarizes research on condition monitoring of rotating equipment using vibration analysis. It discusses various signal processing techniques used for fault detection and diagnosis, including time-domain analysis, frequency domain analysis, time-frequency analysis using wavelet transforms, and support vector machines. It also reviews literature on prognostics approaches that use condition data to predict failures through artificial intelligence techniques. The document aims to provide an overview of recent developments in diagnostic and prognostic models, algorithms, and technologies for processing sensor data from condition monitoring systems.
The document discusses various aspects of condition monitoring through vibration analysis. It defines condition monitoring and different types of maintenance. It explains why condition monitoring is important and some key physical parameters that are measured. It then focuses on condition monitoring through vibration analysis, discussing concepts like amplitude, frequency, causes of vibration, and analyzing case studies of different machines. Key points covered include vibration measurement and analysis, identifying issues like unbalance, misalignment, looseness and bearing defects.
This document discusses various methods of condition monitoring for machines, including vibration monitoring, lubricant analysis, acoustic emission, infrared thermography, and ultrasound emission. Vibration monitoring uses accelerometers to detect vibrations which can indicate developing faults. Lubricant analysis examines oil properties, contaminants, and wear debris to monitor machine health. Acoustic emission detects elastic waves from structural changes to identify cracks. Infrared thermography uses thermal cameras to detect temperature variations that may indicate issues. Ultrasound emission employs transducers that use the piezoelectric effect to generate and detect ultrasound waves for non-destructive testing of materials.
Condition monitoring of rotating machines pptRohit Kaushik
This document discusses condition monitoring of rotating machines. It covers various techniques for monitoring parameters like temperature, vibration, electrical signals and fluxes to detect faults in machines like motors and generators. Local temperature can be monitored using devices embedded in the insulation near hot parts like the winding or core. Vibration is commonly monitored at various frequencies to analyze faults in components. Electrical signals like current and flux are also monitored to detect issues in windings or rotors. Overall, condition monitoring aims to continuously evaluate equipment health and detect early-stage faults in machines.
Fault Detection and Failure Prediction Using Vibration AnalysisTristan Plante
This document discusses using vibration analysis to detect faults and predict failures in rotating equipment like electric motors. It describes an experiment where vibration data was collected from a motor under normal operation and different fault conditions (unbalance, mechanical looseness, bearing defect). The data was analyzed using spectrum analysis software and MATLAB. Specific fault frequencies were identified that corresponded to the type of fault. The results support using vibration analysis to monitor equipment condition and enable predictive maintenance by detecting issues before catastrophic failures occur.
This document provides a summary of common vibration monitoring techniques used to detect machinery failures, including:
- It introduces overall vibration monitoring and trend analysis to detect changes in machinery condition over time.
- Key aspects that affect vibration measurements are frequency range, scale factors, and sensor placement location. Consistently measuring these factors is important for meaningful trend analysis.
- Common vibration monitoring methods are described like measuring vibration amplitude and frequency to understand failure root causes, as different issues generate unique vibration signatures.
Excessive vibration issues in two pole electric motorsAdam Bron
The effects of electric motor failure may be very severe. In case of high speed motors one of most common problems is extensive vibration and its effects. Here we look into the problem to see if it's always related to motor only.
Fault diagnosis of rotating machines using vibrationYousof Elkhouly
This document discusses a method for fault diagnosis of rotating machinery using vibration and bearing temperature measurements. An experimental rig with multiple bearings was used to collect data under healthy and various fault conditions. Vibration data alone did not provide clear diagnosis. Adding bearing temperature measurements as additional features improved diagnosis when principal component analysis was applied. Initial results found supplementing vibration data with temperature gave better fault diagnosis compared to using just vibration.
Electrical machines vibration - causes effects and mitigation - Mr Sunil NaikProSIM R & D Pvt. Ltd.
A beautiful talk by Mr. Sunil Naik - Head of product Development - TMEIC at the Vibration Analysis & Correlation 30-31 May 2016. He threw some light upon the construction of electrical machines and their operations, and also spoke about the causes of Vibration in them. Many causes of Vibration were discussed. Some mitigation techniques of vibration by Design and by practical Counter measures were also discussed in depth.
The document provides an overview of condition monitoring techniques, with a focus on vibration analysis and oil analysis. It discusses how condition monitoring allows maintenance to be scheduled before failures occur. It then describes different machine condition monitoring technologies including vibration analysis, ultrasound analysis, thermal analysis, and oil analysis. The rest of the document goes into technical details about performing vibration analysis and oil analysis to monitor machine health.
The document describes a Machinery Fault Simulator (MFS) that is designed to allow users to study the vibration signatures of common machinery faults in a controlled environment. The MFS features a modular design that can be configured to simulate different machine components and introduce various faults. It includes options like adjustable speed motors, gearboxes, belt drives, and kits to simulate faults in bearings, rotors, shafts, and other components. The document explains that the MFS provides an effective training tool for vibration analysis and predictive maintenance by enabling hands-on learning of machinery fault diagnosis in a safe offline environment.
Condition based monitoring of rotating machines using piezoelectric materialeSAT Publishing House
This document summarizes a study on using piezoelectric materials to monitor the condition of rotating machines. Piezoelectric crystals generate voltage when subjected to vibration or strain. The document details how piezoelectric sensors were attached to a lathe machine to measure voltages from vibrations during different operations. Voltage readings were taken and calibration curves were generated to relate voltages to frequencies for condition monitoring. The results demonstrate the potential of using inexpensive piezoelectric sensors as an alternative to conventional vibration sensors for machine monitoring.
Condition monitoring of rotary machinesAshish Singh
This document discusses concepts for monitoring rotary machines using vibration analysis. It describes how total vibration is the sum of individual vibrations from issues like unbalance, misalignment, and gear or bearing problems. Different parameters are selected for monitoring depending on the frequency range of interest, such as displacement for low frequencies and acceleration for higher frequencies. Signal processing techniques like fast Fourier transforms separate vibration data into individual frequency components to detect issues. Parameters, plots, and orbits are analyzed to diagnose problems and monitor machine condition.
This document discusses condition monitoring techniques including infrared thermography, electric motor testing, oil analysis, and wear particle analysis.
Infrared thermography uses infrared cameras to detect heat patterns that can indicate issues in mechanical and electrical equipment. Electric motor testing evaluates the electrical condition of motors through both static offline tests, like insulation resistance testing, and dynamic online tests using current analysis and flux coils.
Oil analysis examines lubricant condition to identify contamination or wear metal additions that serve as early failure warnings. Wear particle analysis goes further by microscopically analyzing oil samples to classify wear types like corrosive, sliding, or cutting wear and pinpoint their source.
This document provides information about vibration analysis and monitoring. It defines key vibration terms like displacement, velocity, acceleration, and frequency. It describes common applications of vibration analysis in industries. It explains how vibration analysis can be used to improve reliability by identifying root causes of faults and ensuring machines are properly maintained. The document discusses different methods of vibration data collection, from simple meters to professional analyzers. It provides an example of a vibration case study on a centrifugal fan and highlights the importance of vibration monitoring in preventing machine failures.
Condition monitoring of induction motor with a case studyIAEME Publication
This document summarizes a study on condition monitoring of an induction motor. The study utilized multiple monitoring techniques including temperature monitoring, vibration analysis, motor current signature analysis, and shaft voltage measurement. Temperature, vibration, and shaft voltage readings were found to be within normal limits, indicating the motor was in good health. Motor current signature analysis detected no issues, further confirming the healthy state of the motor. The study demonstrated how a combination of condition monitoring techniques can evaluate the overall condition and help plan preventive maintenance for motors.
Condition monitoring of rotating electrical machinesAnkit Basera
Condition monitoring of rotating electrical machines, Construction, Operation, Types, Specification Of Electrical Machines, Different Failure Modes Of Electrical Machines, Failure Modes And Root Causes In Rotating Electrical Machines
The document provides an introduction to vibration analysis, including:
1) An overview of key concepts in vibration measurement such as transducers, sampling, filtering, windows, averaging, and FFT analysis.
2) A discussion of rotating machinery analysis techniques like order tracking and synchronous signal averaging.
3) Details about vibration sources in machines, measurement techniques, and common vibration measures.
This document presents a study on using an artificial neural network technique for flux position estimation and sector selection in direct torque control of an induction motor. Direct torque control aims to provide quick torque response without complex transformations but suffers from high torque ripples. The proposed method uses a neural network for flux position estimation and sector selection to determine the optimal voltage vector, with the goal of reducing torque and flux ripples. The neural network structure is simple to facilitate short training and processing times. Simulation results show the neural network based controller provides high performance speed control of the induction motor.
This document discusses vibration monitoring and analysis techniques for machine maintenance. It covers three types of maintenance schemes: breakdown, preventive, and condition-based maintenance. Vibration monitoring is described as the most common condition monitoring method, where vibration levels are measured to predict failures. Two types of vibration monitoring systems - periodic and permanent - are outlined. Vibration analysis techniques including time-domain and frequency-domain analysis are explained. Data acquisition and interpretation methods are also summarized. The role of computers in vibration-based condition monitoring programs is briefly described.
Vibration Monitoring-Vibration Transducers-Vibration TroubleshootingDhanesh S
Vibration monitoring involves measuring machine vibrations using transducers like accelerometers and analyzing the vibration signals. This helps identify potential issues like imbalance, misalignment, bearing problems, and gear damage. Vibration is measured through devices that collect time signal data and analyze it using techniques like spectral analysis and envelope analysis to produce a vibration signature. This signature provides information on individual frequency amplitudes that can indicate machine faults and their locations. Maintaining machines involves ongoing vibration monitoring to detect issues early and ensure equipment reliability.
1) The document discusses using discrete wavelet transforms to analyze vibration signals from roller bearings to detect faults. It proposes a new feature - summing the squared wavelet decomposition coefficients at each level - and compares it to the traditional energy-based feature.
2) An experiment is described where vibration signals are collected from a test rig under normal conditions and with introduced inner race, outer race, and combined faults. The signals are decomposed using discrete wavelet transforms.
3) Features are then extracted from the wavelet decompositions using both the proposed summed squared coefficient feature and the traditional energy-based feature. A decision tree is used to classify the features and determine which feature performs better at detecting the faults.
This document summarizes a study on vibration analysis of a single row ball bearing for predictive maintenance applications. The study analyzed vibrations from the bearing under different load and speed conditions, as well as with and without a misaligned coupling. It was found that acceleration increases linearly with both load and speed for a properly aligned coupling. With a misaligned coupling, acceleration increases more significantly with load and speed. The results indicate vibration analysis can help detect faults and monitor damage by analyzing how acceleration changes with operating conditions.
Fault Detection and Failure Prediction Using Vibration AnalysisTristan Plante
This document discusses using vibration analysis to detect faults and predict failures in rotating equipment like electric motors. It describes an experiment where vibration data was collected from a motor under normal operation and different fault conditions (unbalance, mechanical looseness, bearing defect). The data was analyzed using spectrum analysis software and MATLAB. Specific fault frequencies were identified that corresponded to the type of fault. The results support using vibration analysis to monitor equipment condition and enable predictive maintenance by detecting issues before catastrophic failures occur.
This document provides a summary of common vibration monitoring techniques used to detect machinery failures, including:
- It introduces overall vibration monitoring and trend analysis to detect changes in machinery condition over time.
- Key aspects that affect vibration measurements are frequency range, scale factors, and sensor placement location. Consistently measuring these factors is important for meaningful trend analysis.
- Common vibration monitoring methods are described like measuring vibration amplitude and frequency to understand failure root causes, as different issues generate unique vibration signatures.
Excessive vibration issues in two pole electric motorsAdam Bron
The effects of electric motor failure may be very severe. In case of high speed motors one of most common problems is extensive vibration and its effects. Here we look into the problem to see if it's always related to motor only.
Fault diagnosis of rotating machines using vibrationYousof Elkhouly
This document discusses a method for fault diagnosis of rotating machinery using vibration and bearing temperature measurements. An experimental rig with multiple bearings was used to collect data under healthy and various fault conditions. Vibration data alone did not provide clear diagnosis. Adding bearing temperature measurements as additional features improved diagnosis when principal component analysis was applied. Initial results found supplementing vibration data with temperature gave better fault diagnosis compared to using just vibration.
Electrical machines vibration - causes effects and mitigation - Mr Sunil NaikProSIM R & D Pvt. Ltd.
A beautiful talk by Mr. Sunil Naik - Head of product Development - TMEIC at the Vibration Analysis & Correlation 30-31 May 2016. He threw some light upon the construction of electrical machines and their operations, and also spoke about the causes of Vibration in them. Many causes of Vibration were discussed. Some mitigation techniques of vibration by Design and by practical Counter measures were also discussed in depth.
The document provides an overview of condition monitoring techniques, with a focus on vibration analysis and oil analysis. It discusses how condition monitoring allows maintenance to be scheduled before failures occur. It then describes different machine condition monitoring technologies including vibration analysis, ultrasound analysis, thermal analysis, and oil analysis. The rest of the document goes into technical details about performing vibration analysis and oil analysis to monitor machine health.
The document describes a Machinery Fault Simulator (MFS) that is designed to allow users to study the vibration signatures of common machinery faults in a controlled environment. The MFS features a modular design that can be configured to simulate different machine components and introduce various faults. It includes options like adjustable speed motors, gearboxes, belt drives, and kits to simulate faults in bearings, rotors, shafts, and other components. The document explains that the MFS provides an effective training tool for vibration analysis and predictive maintenance by enabling hands-on learning of machinery fault diagnosis in a safe offline environment.
Condition based monitoring of rotating machines using piezoelectric materialeSAT Publishing House
This document summarizes a study on using piezoelectric materials to monitor the condition of rotating machines. Piezoelectric crystals generate voltage when subjected to vibration or strain. The document details how piezoelectric sensors were attached to a lathe machine to measure voltages from vibrations during different operations. Voltage readings were taken and calibration curves were generated to relate voltages to frequencies for condition monitoring. The results demonstrate the potential of using inexpensive piezoelectric sensors as an alternative to conventional vibration sensors for machine monitoring.
Condition monitoring of rotary machinesAshish Singh
This document discusses concepts for monitoring rotary machines using vibration analysis. It describes how total vibration is the sum of individual vibrations from issues like unbalance, misalignment, and gear or bearing problems. Different parameters are selected for monitoring depending on the frequency range of interest, such as displacement for low frequencies and acceleration for higher frequencies. Signal processing techniques like fast Fourier transforms separate vibration data into individual frequency components to detect issues. Parameters, plots, and orbits are analyzed to diagnose problems and monitor machine condition.
This document discusses condition monitoring techniques including infrared thermography, electric motor testing, oil analysis, and wear particle analysis.
Infrared thermography uses infrared cameras to detect heat patterns that can indicate issues in mechanical and electrical equipment. Electric motor testing evaluates the electrical condition of motors through both static offline tests, like insulation resistance testing, and dynamic online tests using current analysis and flux coils.
Oil analysis examines lubricant condition to identify contamination or wear metal additions that serve as early failure warnings. Wear particle analysis goes further by microscopically analyzing oil samples to classify wear types like corrosive, sliding, or cutting wear and pinpoint their source.
This document provides information about vibration analysis and monitoring. It defines key vibration terms like displacement, velocity, acceleration, and frequency. It describes common applications of vibration analysis in industries. It explains how vibration analysis can be used to improve reliability by identifying root causes of faults and ensuring machines are properly maintained. The document discusses different methods of vibration data collection, from simple meters to professional analyzers. It provides an example of a vibration case study on a centrifugal fan and highlights the importance of vibration monitoring in preventing machine failures.
Condition monitoring of induction motor with a case studyIAEME Publication
This document summarizes a study on condition monitoring of an induction motor. The study utilized multiple monitoring techniques including temperature monitoring, vibration analysis, motor current signature analysis, and shaft voltage measurement. Temperature, vibration, and shaft voltage readings were found to be within normal limits, indicating the motor was in good health. Motor current signature analysis detected no issues, further confirming the healthy state of the motor. The study demonstrated how a combination of condition monitoring techniques can evaluate the overall condition and help plan preventive maintenance for motors.
Condition monitoring of rotating electrical machinesAnkit Basera
Condition monitoring of rotating electrical machines, Construction, Operation, Types, Specification Of Electrical Machines, Different Failure Modes Of Electrical Machines, Failure Modes And Root Causes In Rotating Electrical Machines
The document provides an introduction to vibration analysis, including:
1) An overview of key concepts in vibration measurement such as transducers, sampling, filtering, windows, averaging, and FFT analysis.
2) A discussion of rotating machinery analysis techniques like order tracking and synchronous signal averaging.
3) Details about vibration sources in machines, measurement techniques, and common vibration measures.
This document presents a study on using an artificial neural network technique for flux position estimation and sector selection in direct torque control of an induction motor. Direct torque control aims to provide quick torque response without complex transformations but suffers from high torque ripples. The proposed method uses a neural network for flux position estimation and sector selection to determine the optimal voltage vector, with the goal of reducing torque and flux ripples. The neural network structure is simple to facilitate short training and processing times. Simulation results show the neural network based controller provides high performance speed control of the induction motor.
This document discusses vibration monitoring and analysis techniques for machine maintenance. It covers three types of maintenance schemes: breakdown, preventive, and condition-based maintenance. Vibration monitoring is described as the most common condition monitoring method, where vibration levels are measured to predict failures. Two types of vibration monitoring systems - periodic and permanent - are outlined. Vibration analysis techniques including time-domain and frequency-domain analysis are explained. Data acquisition and interpretation methods are also summarized. The role of computers in vibration-based condition monitoring programs is briefly described.
Vibration Monitoring-Vibration Transducers-Vibration TroubleshootingDhanesh S
Vibration monitoring involves measuring machine vibrations using transducers like accelerometers and analyzing the vibration signals. This helps identify potential issues like imbalance, misalignment, bearing problems, and gear damage. Vibration is measured through devices that collect time signal data and analyze it using techniques like spectral analysis and envelope analysis to produce a vibration signature. This signature provides information on individual frequency amplitudes that can indicate machine faults and their locations. Maintaining machines involves ongoing vibration monitoring to detect issues early and ensure equipment reliability.
1) The document discusses using discrete wavelet transforms to analyze vibration signals from roller bearings to detect faults. It proposes a new feature - summing the squared wavelet decomposition coefficients at each level - and compares it to the traditional energy-based feature.
2) An experiment is described where vibration signals are collected from a test rig under normal conditions and with introduced inner race, outer race, and combined faults. The signals are decomposed using discrete wavelet transforms.
3) Features are then extracted from the wavelet decompositions using both the proposed summed squared coefficient feature and the traditional energy-based feature. A decision tree is used to classify the features and determine which feature performs better at detecting the faults.
This document summarizes a study on vibration analysis of a single row ball bearing for predictive maintenance applications. The study analyzed vibrations from the bearing under different load and speed conditions, as well as with and without a misaligned coupling. It was found that acceleration increases linearly with both load and speed for a properly aligned coupling. With a misaligned coupling, acceleration increases more significantly with load and speed. The results indicate vibration analysis can help detect faults and monitor damage by analyzing how acceleration changes with operating conditions.
This document presents a study on using acoustic signal analysis to detect faults in bearings. The study develops an experimental setup to acquire acoustic signals from bearings under different conditions, including with and without defects. The acoustic signals are processed using techniques like fast Fourier transforms and wavelet transforms to extract information about faults. Signals are analyzed from bearings with no defects, misalignment, looseness, missing balls, and combinations of defects. Results show the acoustic signal energy at different frequencies for healthy and faulty bearings. This acoustic signal analysis technique can be used to detect bearing faults and failures.
Mems Based Motor Fault Detection in Windmill Using Neural NetworksIJRES Journal
Today wind turbine technology is one of the fastest growing power generation technologies operating in large numbers at harsh and difficult environment sites and it is difficult to monitor each and every windmill separately. There are times when faults occur in motors of windmills are not detected in earlier stage and we come to know about damage when motor gets fully damaged. Here we using wireless monitoring based on MEMS accelerometer sensor which senses the vibrations occurring in the motor and based on the severity of vibrations, sensor sends the data to the controlling unit to take further action. Neural network based work is included to get the accurate and precise vibratory signals to detect fault at a very early stage to avoid full damage to the motor.
This document summarizes a research paper on using MEMS sensors and neural networks to detect faults in the motors of wind turbines. It begins with an abstract that overviews using an accelerometer sensor to detect vibrations in the motor and send the data to a control unit. It then provides background on existing vibration-based fault detection methods and proposes a new method using MEMS sensors, wavelet packet transform analysis of the sensor data, and a neural network classifier to detect faults at an early stage. The document concludes that this method allows accurate and reliable condition monitoring of wind turbines to prevent motor damage.
Fault diagnosis of rolling element bearings using artificial neural network IJECEIAES
Bearings are essential components in the most electrical equipment. Procedures for monitoring the condition of bearings must be developed to prevent unexpected failure of these components during operation to avoid costly consequences. In this paper, the design of a monitoring system for the detection of rolling element-bearings failure is proposed. The method for detecting and locating this type of fault is carried out using advanced intelligent techniques based on a perceptron multilayer artificial neural network (MLP-ANN); its database uses statistical indicators characterizing vibration signals. The effectiveness of the proposed method is illustrated using experimentally obtained bearing vibration data, and the results have shown good accuracy in detecting and locating defects.
This document discusses motor current signature analysis (MCSA) for detecting faults in induction motors. MCSA analyzes current signals to identify faults by comparing signatures from healthy and faulty motors. It has advantages over other monitoring methods as it does not require additional sensors. Signal processing techniques like fast Fourier transforms (FFT), short-time Fourier transforms, and wavelet transforms are used to analyze current signals in the frequency domain and detect fault frequencies. An algorithm is presented that uses the standard deviation of wavelet coefficients to detect faults like loose connections or stator resistance unbalancing. MCSA can detect faults at an early stage to prevent further damage.
Condition monitoring of induction motor with a case studyIAEME Publication
This document summarizes a study on condition monitoring of an induction motor. It discusses various monitoring methods like temperature monitoring, vibration analysis, motor current signature analysis, and shaft voltage measurement. Temperature monitoring identified hotspots indicating potential insulation or cooling issues. Vibration analysis found peaks corresponding to unbalance, misalignment, and bearing or looseness issues. Motor current signature analysis identified rotor bar and joint issues by analyzing current waveforms. Together these methods provided a comprehensive assessment of the motor's health to guide maintenance.
The document presents a project on using nonlinear time-series analysis and machine learning algorithms to identify and predict machine faults in rotating machinery. Sensor data is collected from a machine fault simulator and analyzed using time-series analysis, FFT, recurrence plots, and a GRU machine learning model to classify data from good bearings, faulty bearings, and rubbing conditions and forecast future failures. The analysis identified a faulty bearing as the primary cause of deterioration, while the machine learning model validated the need for prompt intervention to address issues and enable proactive maintenance.
Acoustic emission condition monitoring an application for wind turbine fault ...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Acoustic emission condition monitoring an application for wind turbine fault...eSAT Journals
Abstract Low speed rotating machines which are the most critical components in drive train of wind turbines are often menaced by several technical and environmental defects. These factors contribute to mount the economic requirement for Health Monitoring and Condition Monitoring of the systems. When a defect is happened in such system result in reduced energy loss rates from related process and due to it Condition Monitoring techniques that detecting energy loss are very difficult if not possible to use. However, in the case of Acoustic Emission (AE)technique this issue is partly overcome and is well suited for detecting very small energy release rates. Acoustic Emission (AE) as a technique is more than 50 years old and in this new technology the sounds associated with the failure of materials were detected. Acoustic wave is a non-stationary signal which can discover elastic stress waves in a failure component, capable of online monitoring, and is very sensitive to the fault diagnosis. In this paper the history and background of discovering and developing AE is discussed, different ages of developing AE which include Age of Enlightenment (1950-1967), Golden Age of AE (1967-1980), Period of Transition (1980-Present). In the next section the application of AE condition monitoring in machinery process and various systems that applied AE technique in their health monitoring is discussed. In the end an experimental result is proposed by QUT test rig which an outer race bearing fault was simulated to depict the sensitivity of AE for detecting incipient faults in low speed high frequency machine. Index Terms: Low speed rotating machine, and Condition Monitoring Systems, Acoustic Emission (AE)
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Comparative Analysis of Natural Frequency of Transverse Vibration of a Cantil...IRJET Journal
This document presents a comparative analysis of the natural frequency of transverse vibration of a cantilever beam using analytical and experimental methods. Analytical calculations are performed to determine the natural frequencies of the first three modes of vibration of the cantilever beam. Experimental testing is conducted using an impact hammer, accelerometer, and FFT analyzer. The natural frequencies measured experimentally are found to be close to those calculated analytically. The results demonstrate that analytical and experimental methods can both accurately determine the natural frequencies of a cantilever beam's vibration.
A Study of Ball Bearing’s Crack Using Acoustic Signal / Vibration Signal and ...INFOGAIN PUBLICATION
The field of fault diagnostic in rotating machinery is vast, including the diagnosis of items such as rotating shafts, rolling element bearings, couplings, gears and so on. Vibration analysis is the main condition monitoring technique for machinery maintenance. The different types of faults that are observed in these areas and the methods of their diagnosis are accordingly great, including vibration analysis, model-based techniques, and statistical analysis and artificial intelligence techniques. However, they have difficulties with certain applications whose behavior is non-stationary and transient nature.
A Study of Ball Bearing’s Crack Using Acoustic Signal / Vibration Signal and ...INFOGAIN PUBLICATION
The field of fault diagnostic in rotating machinery is vast, including the diagnosis of items such as rotating shafts, rolling element bearings, couplings, gears and so on. Vibration analysis is the main condition monitoring technique for machinery maintenance. The different types of faults that are observed in these areas and the methods of their diagnosis are accordingly great, including vibration analysis, model-based techniques, and statistical analysis and artificial intelligence techniques. However, they have difficulties with certain applications whose behavior is non-stationary and transient nature.
A Study of Ball Bearing’s Crack Using Acoustic Signal / Vibration Signal and ...INFOGAIN PUBLICATION
The field of fault diagnostic in rotating machinery is vast, including the diagnosis of items such as rotating shafts, rolling element bearings, couplings, gears and so on. Vibration analysis is the main condition monitoring technique for machinery maintenance. The different types of faults that are observed in these areas and the methods of their diagnosis are accordingly great, including vibration analysis, model-based techniques, and statistical analysis and artificial intelligence techniques. However, they have difficulties with certain applications whose behavior is non-stationary and transient nature.
Vibration analysis uses sensors to measure vibrations in machines and identify potential failures or faults. Analyzing vibration data can help predict maintenance needs and improve machine reliability. Sensors are mounted on machines using various methods to measure vibrations generated by rotating components like motors, pumps and gears. The vibration measurements are analyzed to diagnose issues and plan repairs for machines before failures occur.
Performance Monitoring of Vibration in Belt Conveyor SystemIJERA Editor
We are always using some kind of machines in our daily life starting from fan, refrigerator and washing machines at home. In case of industries of industrial machinery items condition monitoring is important to know onset impending defects. There are so many types of indicating phenomenon such as vibration, heat, debris in oil, noise and sounds which emanate from these in efficiently running machines. This paper presents the vibration related fault identification and maintenance of belt conveyor systems (BCS). After analyzing the spectrum and vibration readings, it was observed that a combination of parallel and angular misalignment between motor & gear box was present causing high axial and radial vibration. The defect was rectified by mechanical maintenance activities and latter the vibration was found reduced within limit. Also the vibration readings were taken after rectification. The above results are presented in this paper.
Design of Vibration Test Fixture for Opto-Electronic EquipmentIJMERJOURNAL
ABSTRACT : In this paper an attempt is made in designing vibration test fixture for opto-electronic equipment. It can be achieved by formulating basic or preliminary 3D CAD assembled model followed by attaching material to its components. The analysis carried by defining the contact conditions of every part of it, defining the fixing conditions, applying loads virtually, good quality meshing, followed by optimization of the same by taking concurrence from the results of Linear Harmonic Structural Vibration Analysis. SolidworksSimulation premium software is used for modelling and solving the Linear Harmonic Structural vibration analysis for all Environmental Stress Screening (ESS) tests like vibration, shock for elimination of failures before physical testing. The comparison between experimental results and simulation results are presented in this paper.
Vibration analysis is used to monitor machinery health, detect deterioration, and enable predictive maintenance. The BellaDati platform collects vibration and other sensor data from equipment in real-time. Its machine learning algorithms analyze the data to identify abnormal vibration patterns and predict failures. This allows issues to be addressed before breakdowns occur, improving safety, productivity and reducing costs.
Similar to Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission Technique (20)
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
The document proposes a hybrid technique using Anisotropic Scale Invariant Feature Transform (A-SIFT) and Robust Ensemble Support Vector Machine (RESVM) to accurately identify faces in images. A-SIFT improves upon traditional SIFT by applying anisotropic scaling to extract richer directional keypoints. Keypoints are processed with RESVM and hypothesis testing to increase accuracy above 95% by repeatedly reprocessing images until the threshold is met. The technique was tested on similar and different facial images and achieved better results than SIFT in retrieval time and reduced keypoints.
This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
This document describes a wireless environment monitoring system that utilizes soil energy as a sustainable power source for wireless sensors. The system uses a microbial fuel cell to generate electricity from the microbial activity in soil. Two microbial fuel cells were created using different soil types and various additives to produce different current and voltage outputs. An electronic circuit was designed on a printed circuit board with components like a microcontroller and ZigBee transceiver. Sensors for temperature and humidity were connected to the circuit to monitor the environment wirelessly. The system provides a low-cost way to power remote sensors without needing battery replacement and avoids the high costs of wiring a power source.
1) The document proposes a model for a frequency tunable inverted-F antenna that uses ferrite material.
2) The resonant frequency of the antenna can be significantly shifted from 2.41GHz to 3.15GHz, a 31% shift, by increasing the static magnetic field placed on the ferrite material.
3) Altering the permeability of the ferrite allows tuning of the antenna's resonant frequency without changing the physical dimensions, providing flexibility to operate over a wide frequency range.
This document summarizes a research paper that presents a speech enhancement method using stationary wavelet transform. The method first classifies speech into voiced, unvoiced, and silence regions based on short-time energy. It then applies different thresholding techniques to the wavelet coefficients of each region - modified hard thresholding for voiced speech, semi-soft thresholding for unvoiced speech, and setting coefficients to zero for silence. Experimental results using speech from the TIMIT database corrupted with white Gaussian noise at various SNR levels show improved performance over other popular denoising methods.
This document reviews the design of an energy-optimized wireless sensor node that encrypts data for transmission. It discusses how sensing schemes that group nodes into clusters and transmit aggregated data can reduce energy consumption compared to individual node transmissions. The proposed node design calculates the minimum transmission power needed based on received signal strength and uses a periodic sleep/wake cycle to optimize energy when not sensing or transmitting. It aims to encrypt data at both the node and network level to further optimize energy usage for wireless communication.
This document discusses group consumption modes. It analyzes factors that impact group consumption, including external environmental factors like technological developments enabling new forms of online and offline interactions, as well as internal motivational factors at both the group and individual level. The document then proposes that group consumption modes can be divided into four types based on two dimensions: vertical (group relationship intensity) and horizontal (consumption action period). These four types are instrument-oriented, information-oriented, enjoyment-oriented, and relationship-oriented consumption modes. Finally, the document notes that consumption modes are dynamic and can evolve over time.
The document summarizes a study of different microstrip patch antenna configurations with slotted ground planes. Three antenna designs were proposed and their performance evaluated through simulation: a conventional square patch, an elliptical patch, and a star-shaped patch. All antennas were mounted on an FR4 substrate. The effects of adding different slot patterns to the ground plane on resonance frequency, bandwidth, gain and efficiency were analyzed parametrically. Key findings were that reshaping the patch and adding slots increased bandwidth and shifted resonance frequency. The elliptical and star patches in particular performed better than the conventional design. Three antenna configurations were selected for fabrication and measurement based on the simulations: a conventional patch with a slot under the patch, an elliptical patch with slots
1) The document describes a study conducted to improve call drop rates in a GSM network through RF optimization.
2) Drive testing was performed before and after optimization using TEMS software to record network parameters like RxLevel, RxQuality, and events.
3) Analysis found call drops were occurring due to issues like handover failures between sectors, interference from adjacent channels, and overshooting due to antenna tilt.
4) Corrective actions taken included defining neighbors between sectors, adjusting frequencies to reduce interference, and lowering the mechanical tilt of an antenna.
5) Post-optimization drive testing showed improvements in RxLevel, RxQuality, and a reduction in dropped calls.
This document describes the design of an intelligent autonomous wheeled robot that uses RF transmission for communication. The robot has two modes - automatic mode where it can make its own decisions, and user control mode where a user can control it remotely. It is designed using a microcontroller and can perform tasks like object recognition using computer vision and color detection in MATLAB, as well as wall painting using pneumatic systems. The robot's movement is controlled by DC motors and it uses sensors like ultrasonic sensors and gas sensors to navigate autonomously. RF transmission allows communication between the robot and a remote control unit. The overall aim is to develop a low-cost robotic system for industrial applications like material handling.
This document reviews cryptography techniques to secure the Ad-hoc On-Demand Distance Vector (AODV) routing protocol in mobile ad-hoc networks. It discusses various types of attacks on AODV like impersonation, denial of service, eavesdropping, black hole attacks, wormhole attacks, and Sybil attacks. It then proposes using the RC6 cryptography algorithm to secure AODV by encrypting data packets and detecting and removing malicious nodes launching black hole attacks. Simulation results show that after applying RC6, the packet delivery ratio and throughput of AODV increase while delay decreases, improving the security and performance of the network under attack.
The document describes a proposed modification to the conventional Booth multiplier that aims to increase its speed by applying concepts from Vedic mathematics. Specifically, it utilizes the Urdhva Tiryakbhyam formula to generate all partial products concurrently rather than sequentially. The proposed 8x8 bit multiplier was coded in VHDL, simulated, and found to have a path delay 44.35% lower than a conventional Booth multiplier, demonstrating its potential for higher speed.
This document discusses image deblurring techniques. It begins by introducing image restoration and focusing on image deblurring. It then discusses challenges with image deblurring being an ill-posed problem. It reviews existing approaches to screen image deconvolution including estimating point spread functions and iteratively estimating blur kernels and sharp images. The document also discusses handling spatially variant blur and summarizes the relationship between the proposed method and previous work for different blur types. It proposes using color filters in the aperture to exploit parallax cues for segmentation and blur estimation. Finally, it proposes moving the image sensor circularly during exposure to prevent high frequency attenuation from motion blur.
This document describes modeling an adaptive controller for an aircraft roll control system using PID, fuzzy-PID, and genetic algorithm. It begins by introducing the aircraft roll control system and motivation for developing an adaptive controller to minimize errors from noisy analog sensor signals. It then provides the mathematical model of aircraft roll dynamics and describes modeling the real-time flight control system in MATLAB/Simulink. The document evaluates PID, fuzzy-PID, and PID-GA (genetic algorithm) controllers for aircraft roll control and finds that the PID-GA controller delivers the best performance.
Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
- An overly permissive IAM role configuration can lead to privilege escalation by creating a role with administrative privileges and allow a user to assume this role.
- Objective: Show how overly permissive IAM roles can lead to privilege escalation.
- Steps:
- Create role with administrative privileges.
- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
Try at [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELijaia
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Generative AI Use cases applications solutions and implementation.pdfmahaffeycheryld
Generative AI solutions encompass a range of capabilities from content creation to complex problem-solving across industries. Implementing generative AI involves identifying specific business needs, developing tailored AI models using techniques like GANs and VAEs, and integrating these models into existing workflows. Data quality and continuous model refinement are crucial for effective implementation. Businesses must also consider ethical implications and ensure transparency in AI decision-making. Generative AI's implementation aims to enhance efficiency, creativity, and innovation by leveraging autonomous generation and sophisticated learning algorithms to meet diverse business challenges.
https://www.leewayhertz.com/generative-ai-use-cases-and-applications/
Accident detection system project report.pdfKamal Acharya
The Rapid growth of technology and infrastructure has made our lives easier. The
advent of technology has also increased the traffic hazards and the road accidents take place
frequently which causes huge loss of life and property because of the poor emergency facilities.
Many lives could have been saved if emergency service could get accident information and
reach in time. Our project will provide an optimum solution to this draw back. A piezo electric
sensor can be used as a crash or rollover detector of the vehicle during and after a crash. With
signals from a piezo electric sensor, a severe accident can be recognized. According to this
project when a vehicle meets with an accident immediately piezo electric sensor will detect the
signal or if a car rolls over. Then with the help of GSM module and GPS module, the location
will be sent to the emergency contact. Then after conforming the location necessary action will
be taken. If the person meets with a small accident or if there is no serious threat to anyone’s
life, then the alert message can be terminated by the driver by a switch provided in order to
avoid wasting the valuable time of the medical rescue team.
Digital Twins Computer Networking Paper Presentation.pptxaryanpankaj78
A Digital Twin in computer networking is a virtual representation of a physical network, used to simulate, analyze, and optimize network performance and reliability. It leverages real-time data to enhance network management, predict issues, and improve decision-making processes.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
Tools & Techniques for Commissioning and Maintaining PV Systems W-Animations ...Transcat
Join us for this solutions-based webinar on the tools and techniques for commissioning and maintaining PV Systems. In this session, we'll review the process of building and maintaining a solar array, starting with installation and commissioning, then reviewing operations and maintenance of the system. This course will review insulation resistance testing, I-V curve testing, earth-bond continuity, ground resistance testing, performance tests, visual inspections, ground and arc fault testing procedures, and power quality analysis.
Fluke Solar Application Specialist Will White is presenting on this engaging topic:
Will has worked in the renewable energy industry since 2005, first as an installer for a small east coast solar integrator before adding sales, design, and project management to his skillset. In 2022, Will joined Fluke as a solar application specialist, where he supports their renewable energy testing equipment like IV-curve tracers, electrical meters, and thermal imaging cameras. Experienced in wind power, solar thermal, energy storage, and all scales of PV, Will has primarily focused on residential and small commercial systems. He is passionate about implementing high-quality, code-compliant installation techniques.
Supermarket Management System Project Report.pdfKamal Acharya
Supermarket management is a stand-alone J2EE using Eclipse Juno program.
This project contains all the necessary required information about maintaining
the supermarket billing system.
The core idea of this project to minimize the paper work and centralize the
data. Here all the communication is taken in secure manner. That is, in this
application the information will be stored in client itself. For further security the
data base is stored in the back-end oracle and so no intruders can access it.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Mechatronics is a multidisciplinary field that refers to the skill sets needed in the contemporary, advanced automated manufacturing industry. At the intersection of mechanics, electronics, and computing, mechatronics specialists create simpler, smarter systems. Mechatronics is an essential foundation for the expected growth in automation and manufacturing.
Mechatronics deals with robotics, control systems, and electro-mechanical systems.
Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission Technique
1. IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 7, Issue 4 (Jul. - Aug. 2013), PP 52-60
www.iosrjournals.org
www.iosrjournals.org 52 | Page
Assessment of Gearbox Fault DetectionUsing Vibration Signal
Analysis and Acoustic Emission Technique
Vimal Saxena1
Nilendu Kar Chowdhury2
S. Devendiran3
1
B-tech, School of Mechanical and Building Science, VIT University, India
2
B-tech, School of Mechanical and Building Science, VIT University, India
3
Asst. Professor, School of Mechanical and Building Science, VIT University, India
Abstract: Maintenance is a set of organised activities that are carried out in order to keep an item in its best
operational condition with minimum cost acquired. Predictive maintenance (PdM) is one of the maintenance
program that recommends maintenance decisions based on the information collected through condition
monitoring techniques, statistical process control or equipment performance for the purpose of early detection
and elimination of equipment defects that could lead to unplanned downtime of machinery or unnecessary
expenditures. Particularly Gears and rolling element bearings are critical elements in rotating machinery, so
predictive maintenance is often applied to them. Fault signals of gearboxes or rolling-element bearings are non-
stationary. This paper concludes with a brief discussion on current practices of PDM methodologies such as
vibration analysis and Acoustic Emission analysis, which are widely used as they offers a complimentary tool
for health monitoring or assessment of gears in rotating machineries.
Keywords:Acoustic emission, Data mining, Signal processing, Vibration Analysis
I. INTRODUCTION
The ever growing need to condition monitor a gear box, which plays a significant role as a machine
element and finds its usage in wide variety of domestic and industrial application, especially in power
transmission system, has promoted research in designing and implementing a rapid and accurate valuation of
non-destructive techniques so as to prevent performance degradation of machinery or even catastrophic failure
of the same. It is a well noticed fact that fault in a machine can be well noticed by the kind of noise it makes and
same can be detected from its vibration. The ability to monitor the condition of machines in operating condition
is one of major breakthrough in this area of research which is referred as "predictive" maintenance. The method
can vitalize continuously operating plant such as the power generating and chemical industries, and can also be
of considerable use in development of various machines. The present paper is a general discussion of the
different analysis techniques which have been and can be applied in vibration signature analysis as well as in
acoustic emission.
TYPES OF DEFECT
Gears and gearboxes are generally substantially made for high performance and reliability. However,
problems do occur, and many are caused by static as well as dynamic reasons. Static causes which comprises of
manufacturing defects and setting up errors, which can be observed even when the object is still whereas
dynamic errors are those which can only be detected if either the object or the viewpoint is moving. Vibration
signature analysis and Acoustic emission are the most popular techniques for gear fault diagnostics. In a
machine under operation, vibration is always present. The levels of vibration usually increase with deterioration
in the condition of the machine.
Table 1: Gear Failure Mechanisms
Failure
Mechanisms Reason for damage Name of the process Result
Mechanical
damage
Permanent indentation creating
gear meshing
Brinelling Indentation
Crack damage Manufacturing defect orstress
due to overload
Crack Loss of dimensioning
Wear damage Gradual deterioration Scuffing -
Insufficient
lubrication and
contamination
Friction
- Accelerate scuffing
2. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 53 | Page
Incorrect design Poor choice of bearing type or
sizefor required operation.
- Low load carrying capacity
or low speed rating
Thermal
instability
Large temperature difference
builds up
- It causes the bearings to
lose internal clearance and
become pre-loaded which
results in increase in heat
generation.
Misalignment
Manufacturing or setting up
errors, elastic deflection of
component under load , thermal
expansion
-
Leads to premature pitting,
cage wear and finally
failure.
Fatigue damage Material fatigue after
certain running
-
Formation of minute crack
propagated
Faulty
installation
Excessive pre loading and
misalignment
- Noise running
The above defects are common in rotating gears. Vibration and acoustic emission are two important
parameters which must be taken into consideration while examining a machine or its parts for defects. Both
the techniques have their own importance in different working conditions. Various sensors records vibration
signatures and acoustic emissions [1].
II. FAULT DETECTION TECHNIQUES
There are several techniques that can be employed to predict the condition of gears; these
includevibration monitoring, acoustic emission, oil analysis, etc.
Methods of analysis
Acoustic
emission
Oil
Analysis Vibration SPM meter
Misalignment X
Gear damage X X X
Mechanical looseness X X
Mechanical rubbing X X X
Noise X X
Cracking X X
Minute gear damage X
Minute Cracking X
III. VIBRATIONAL ANALYSIS
The vibrational signals so obtained should first be converted into an electrical signal by a suitable
transducer. Transducers are of mainly three types each of which measures velocity, relative displacement, and
acceleration respectively. Acceleration transducers namely “accelerometers” are preferred over the other two as
they have a very wide frequency range and dynamic range. There show a great deal of physical stability as they
are very rugged and have no moving parts. With very small mass and physical dimension the accelerometer aces
the other two methods.
The high impedance accelerometers can be minimized by using by using transistorized preamplifiers
which convert from high impedance to low impedance and which at the same time can be used for signal
conditioning such as amplification and integration.
The complex vibration signals, composed of mixtures of sinusoidal waveform of different waveform
of different amplitudes, frequencies and phase differences can be broken down to vibration signals onto
frequency components as shown in fig 1.
The process of breaking down of vibration signals into individual frequency component is called
frequency analysis. Time domain consists of amplitude that varies with time and frequency is where the
magnitude varies with frequency.
3. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 54 | Page
Fig 1: Typical vibration signals in time and frequency domains (Bruel&Kjaer2)
Once the signal is acquired by the accelerometer, it gives a voltage reading that corresponds to the
level of vibration. The analog signals given by the accelerometer are then collected by the Data Acquisition
Card and transform them into digital signals so that it can read by an analyzing interface. The analyzing
interface (computer software) is used to perform and use the analysis methods [3].
The figure 2 shown below shows the various steps involved in the vibration signature analysis
of a sample and the synchronized order of its principle of working.
FLOW CHART OF VIBRATION SIGNATURE ANALYSIS
Fig.2Vibration signature analysis
IV. ACOUSTIC EMISSION TECHNIQUE:
Acoustic Emission(AE) is defined as the class of phenomenon whereby transient elastic waves are
generated by the rapid release of energy from localized sources like places transient relaxation of stress and
strain fields. Fracture, plastic deformation crack initiation and growth are a few examples of the phenomenon
resulting in AE. This dynamic nature of AE makes it highly potential technique for monitoring the integrity
of critical structures and components.
First step of AE is to collect the signals from the gears. The sensing element for collecting the
signals will be AE sensor. The analog signals so obtained are then collected by the Data Acquisition Card
and transform them into digital signals so that it can read by an analyzing interface. The analyzing interface
(computer software) is used to perform and use the analysis methods[4].
The following fig.3 shows us the various steps in ordered fashion to be followed during the acoustic
emission analysis of samples.
4. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 55 | Page
FLOW CHART OF ACOUSTIC EMISSION TECHNIQUE
Fig. 3 Acoustic Emission technique
The process flow of the two techniques mentioned above can be summarized as follows:
GENERAL SETUP USED
V. ANALOG TO DIGITAL CONVERSION:
The process of converting analog signal (time domain) into digital form for further processing of the
acquired signal can be achieved by microprocessors and works in power of two, refer to as binary numbers. A
12-bit ADC processor provides 4096 (212
) and a 16-bit ADC processor has a 65536 discrete intervals. The
analog wave form is sampled at a fixed time interval and reconstructed to produce a digitized waveform. This
ability of reproducing the original waveform totally depends on the spacing between the time interval and the
number of samples points per unit time. This process is called sampling rate of sampling frequency.
Nyquist sampling theory states that in ADC conversion, the sampling must be twice the highest frequency
component of interest. Fig 2 shows an example of undersampling (aliasing), which can be defined as a
phenomenon which arises when sampling rate is less than double the wave frequency. With four sample points
in 3ms, a wave of lower frequency (represented as dotted lines) appears and is not a valid representation of the
signals. This can be corrected by allowing the low frequency signals to pass and blocking the high frequency
signals. This is achieved by fixing an anti-aliasing filter.
A/C (with
VFD)
or D/C
motor
Gear box
(any type of
gear) setup
Load using
dynamometer/brak
e system/others
Vibration/A
.Esensor
Signal
processing
using unit
Classifier
(soft
tool)unit
5. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 56 | Page
Fig 4: An example of aliasing (undersampling) [5]
VI. SIGNAL PROCESSING
Signal processing is the enabling technology for the generation, transformation, andinterpretation of
information and it‟s a very promising tool for the researchers in the field of non-destructive techniques. It
comprises the theory, algorithms, architecture, implementation, and applications related to processing
information contained in many different formats broadlydesignated as signals. It is the mathematical
manipulation of an information signal to modify or improve it in some way. It is characterized by the
representation of discrete time, discrete frequency, or other discrete domain signals by a sequence of numbers or
symbols and the processing of these signals.
SIGNAL PROCESSING TECHNIQUES:
Time Domain Techniques
Frequency Domain Technique
Time Frequency Analysis
Envelope Analysis
6.1 TIME DOMAIN TECHNIQUES
Time domain is the analysis of different parameters with respect to time. These parameters may include
mathematical functions, physical signals, or time series of economic and environmental data. Commonly used
tool to visualize real world signals in the time domain is oscilloscope.
For the analysis of recorded vibration and acoustic emission, time domain technique is one of the simpler
approaches to detect and diagnose the same. There are n numbers of statistical parameters associated with the
time domain technique. Some of which are RMS, Peak, Crest factor, Kurtosis,Clearancefactor, Impulse factor.
ROOT MEAN SQUARE VALUE(RMS): The RMS value is computed by taking into account the time history of
wave.It is a measure of the energy content in the vibration signature and hence is one of the most relevant
statistical parameter.
𝑅𝑀𝑆 =
1
𝑛
𝑥2(𝑡)𝑛
PEAK(MAXIMUM VALUE):The peak value of signal is one of the important features for diagnosis.
The value indicates the maximum value without any consideration of the time history of the wave.
𝑃𝑒𝑎𝑘 =
1
2
(max 𝑥 𝑡 − min 𝑥 𝑡 )
CREST FACTOR:The crest factor also sometimes called the „peak-to-rms‟ ratio is defined as the ratio of peak
value of a waveform to its RMS value.
𝐶𝑟𝑒𝑠𝑡𝑓𝑎𝑐𝑡𝑜𝑟 =
𝑝𝑒𝑎𝑘
𝑅𝑀𝑆
KURTOSIS:Kurtosis is obtained from the fourth order central moment(moment about the mean) of amplitude
probability distribution and is defined as-
𝐾𝑢𝑟𝑡𝑜𝑠𝑖𝑠 =
1
𝑁
𝑥 𝑖 −𝑥 4𝑁
𝑖=1
𝑅𝑀𝑆 4
IMPULSE FACTOR:The impulse factor which is also found to be an indicator of bearing faults is defined as the
ratio of the peak value to mean value of the time signal.
𝐼𝑚𝑝𝑢𝑙𝑠𝑒𝑓𝑎𝑐𝑡𝑜𝑟 =
𝑝𝑒𝑎𝑘
1
𝑁
𝑥 𝑖𝑁
𝑖=1
SHAPE FACTOR: Shape factor is defined as the ratio of the RMS to mean value.It represents changes under
unbalance and misalignment.
6. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 57 | Page
𝑆𝑎𝑝𝑒𝑓𝑎𝑐𝑡𝑜𝑟 =
𝑅𝑀𝑆
1
𝑁
𝑥 𝑖𝑁
𝑖=1
Where𝑥denotes the mean value of the discrete time signal x (t) having N data points. Other time domain
parameters are the clearance factor, impulse factor and shape factor. These three non-dimensional vibration
amplitude parameters were found to be useful under simulation conditions using a Gaussian probability density
function model of fatigue spalling. The clearance and impulse factors were the most useful with the clearance
factor being the most sensitive and generally robust for detection of incipient fatigue spalling.
P.D.McFadden used the time domain technique in his Interpolation techniques for time domain
averagingvibration of gear, Mechanical System and signal Processing(1989),Examination of a technique for the
early detection of failure in gears by signal processing of the time domain average of the meshing
vibration(1987) [6].
K.Umezawa.T.Ajima and H.Houjoh in their work “An acoustic method to predict tooth surface failure of in
service gears” used the time domain technique to predict the failure analysis of gear mechanism [7].
6.2 FREQUENCY DOMAIN TECHNIQUE
Frequency domain is the domain for analysis of mathematical functions or signals with respect to
frequency, rather than time. To analyse the frequency distribution of vibration waveforms it is necessary to
transform the time domain signal into frequency domain. Fourier transform is used to process the vibration
signals obtained from time domain into the frequency domain in the form of Fast Fourier Transform [FFT].
Fig 5: Fourier transformation to time domain signal to frequency domain.
The principal advantage of the method is that the repetitive nature of the vibration signals is clearly
displaced as peaks in the frequency spectrum at the frequency where the repetition takes place.A frequency
domain representation can also include information on the phase shift that must be applied to each sinusoid in
order to be able to recombine the frequency components to recover the original time signal.
If adiscrete time signal x (t) represents a sampled periodic function with period T, the Fourier series
expansion of x (t) can be obtained from the Fourier integral
𝑋 𝑓 =
1
𝑇
𝑥 𝑡 𝑒
𝑇/2
−𝑇/2
^−𝑖2𝜋𝑓𝑡
𝑑𝑡
Where f represents discrete equally spaced frequencies being multiples of the reciprocal of the period
T.The power spectrum P(f)can be defined as the magnitude or power obtained from the Fourier integral and can
beobtained by:
P( f ) = E[X( f )X*( f )]
Where*represents complex conjugation and E [ ] represents the expected value.
Spectra Analysis provides frequency domain amplitude in terms of displacement, velocity, acceleration
or phase. Auto-spectrum or power spectrum is a similarity measurement in the frequency domain; the
7. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 58 | Page
amplitudes are expressed as the square of their magnitudes. Cross-spectrum is a similarity measurement of two
functions in the frequency domain.
Cepstrum analysis proves to be advantageous as the periodic harmonics, which are commonly
experienced in gearboxes, can be detected even when they are covered within a high background noise.
Cepstrum analysis may not work when more than two signals have been convolved in time domain.
CheeKeongTan,PhilIrving,DavidMba studied the prognosis of gear life using AE technique by
allowing natural pitting of spur gears.In their test they monitored vibration,AE and SOA throughout the test
period to correlate it to the natural degradation of the gear box.They found that based on the analysis of rms
levels AE is more sensitive than the either of the rest[8].
Tim Toutountzakis,CheeKeong Tan and David Mba applied the AE technique to seeded gear fault
detection and investigated the effectiveness of AE for gear defect identification and also its difficulties[9].
Bispectrumis yet another technique which is mainly employed to detect gear fault and have an edge over Fourier
transform as cited by Zheng et al.., 2002that fourier transform is based on the assumption that the vibration
signals are stationary. This bispectrum analysis has been proven to be effective in this situation. It can capture
characteristic frequency, identify the phasic information and express nonlinear advantages (Huang et al., 2006).
Liu et al. (2008) used the bispectrum and 1(1/2)-dimension spectrum to diagnose a gearbox with various pitting
faults. They concluded that bispectral analysis was very sensitive to the gear faults.
Fu et al. (2009) applied the bispectrum technique to the gear wear fault detection and identification and
Zhang (2006) to the gear crack fault diagnosis. Their studies showed that the bispectrum could be used as a
diagnostic tool for gear faults detection.
6.3 TIME FREQUENCY TECHNIQUE
Time Frequency analysis is the technique in which both frequency and time domains are studied to
represent a signal processing. Instead of the conventional method of studying a 1-dimensional analysis and some
transform, time frequency analysis studies a 2-dimensional signal whose function is a 2-dimensional real plane.
The most basic form of time–frequency analysis is the short-time Fourier transform (STFT), but more
sophisticated techniques have been developed, notably wavelets.
The Short Time Fourier Transform of a signal x( t ) using a window function g( t ) is defined as
follows-
𝑆𝑇𝐹𝑇(𝑓, 𝑠) = 𝑥 𝑡 𝑔(𝑡 − 𝑠)𝑒
∞
−∞
^−𝑖2𝜋𝑓𝑡
𝑑𝑡
The wavelet families are:
CONTINUOUS WAVELET TRANSFORM: A continuous wavelet transform (CWT) is used to divide a
continuous-time function into wavelets. Unlike Fourier transform, the continuous wavelet transform possesses
the ability to construct a time-frequency representation of a signal that offers very good time and frequency
localization. In mathematics, the continuous wavelet transform of a continuous, square-integrable
function at a scale and translational value is expressed by the following integral
MORLET WAVELET TRANSFORM:A continuous function in both the time domain and the frequency
domain is called the mother wavelet. The main purpose of the mother wavelet is to provide a source function to
generate the daughter wavelets which are simply the translated and scaled versions of the mother wavelet.
DISCRETE WAVELET:In numerical analysis and functional analysis, a discrete wavelet
transform (DWT) is any wavelet transform for which the wavelets are discretely sampled. As with other wavelet
transforms, a key advantage it has over Fourier transforms is temporal resolution: it captures both frequency and
location information (location in time).They are of two types:
(a)Haar wavelets
(b)Daubechies wavelets
M.Elforjani,D.Mba,A,Sire and A.Muhammad worked on the condition monitoring of key components
in rotating machinery such as gear box with AE and made comparisons with vibration analysis. Their
observations revealed that AE parameters such as r.m.s and energy are more reliable, robust and sensitive to the
detection of faults and defects [10].
8. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 59 | Page
K.Umezawa,T.Ajima and H.Houjoh diagnosed the extent of pitting fatigue on the basis of a frequency
fluctuating analyzing method. The results obtained by them are by pitting fatigue increased, the fluctuation
become stronger and the F/V output increased. This increases correlates with the number of load cycles by using
AE techniques [11].
6.4 ENVELOPE ANALYSIS (HIGH FREQUENCY RESONANCE TECHNIQUE – HFRT)
The technique is extensively used in vibration analysis for rolling element fault diagnosis. The
technique utilizes the high frequency region of the frequencyspectrum.The interaction of the defect in the gear
produces pulses of very short duration, whereas the defect strikes the rotation motion of the system. These
pulses excite the natural frequency of the gear elements, resulting in the increase in the vibration energy at these
high frequencies.The resonant frequencies can be calculated theoretically. Each gear element has a characteristic
rotational frequency. With a defect on a particular bearing element, an increase in the vibration energy at this
element rotational frequency may occur. This defect frequency can be calculated from the geometry of the
bearing and element rotational speed.
This technique allows a small bandwidth in the high frequency region to be reproduced in lower
frequency waveform. Other high frequency commercial analysis techniques include PeakVue, Spike Energy
(gSE), Spectral Emission Energy (SEE) and the Shock Pulse Method (SPM).
VII. DATA MINING TECHNIQUES
Data Mining, also called as data or knowledge discovery, is a process used in different manufacturing
industries to analyze data from different views and derive the useful information from them. It is one of the
many analytical tools for analyzing data yet the most efficient one. It helps the user to find correlation and
patterns among variety of different fields in large relational databases. The use of data mining techniques began
in the early 1990s and has paved its path ever since. Now a days data mining is used to extract useful data that
finds useful in predictive maintenance, fault maintenance, quality assurance, scheduling, and decision support
systems. Many signal processing techniques have been developed and applied for machine diagnosis in this
area.Decision trees one of the most important techniques of data mining are tree shaped structures that
represents set of decisions. Rules are generated from these decisions to classify the dataset. Specific decision
tree methods include Classification and Regression Trees (CART) and Chi Square Automatic Interaction
Detection (CHAID).For classification of dataset CART and CHAID are used. Rules can be established for a
new dataset which would predict which records will have which outcome. A two way splits is created by the
CART to segments a dataset while multi way splits are created by CHAID to segment a dataset using square
tests. CART typically requires less data preparation than CHAID.He et al. (2011) used decision tree method to
identify fault in of mean shifts in bivariate processes inrealtime[12]. Artificial neural networks and Fuzzy Logic
Systems establish a nonlinear I/O relationship which promotes mapping the input of the system to its output.
The complex nonlinear relation is reconstructed using simple functions such as sigmoid or radial which
could be adjusted by means of appropriate parameter and synaptic weight.Artificial neural network is considered
to be a star technique as it can readjust as per the requirement automatically during the training phase based on
the I/O data.On the contrary in FLSs, the I/O spaces gets partitioned into several typically overlapping areas
whose shapes can be determined by assigned memberships functions and its mapping relation is governed by
simple IF-THEN rule. The major advantages of FLSs are that it can handle imprecise data, its physical
transparency and the interpretability offered by it. When the inputs are the decision variables and the I/O space
is seen as a searching space and the outputs are the performance indicator of the search problem, GAs proves a
versatile tool for evaluating a best input solution.Kasabov,Marzi,Markou and Singh used many different
methods based on artificial neural network which were developed for online surveillance, fault detection and
learning abilities[13] [14] [15]. Wang (2002), used Artificial neural network (ANN), Fuzzy Logic System
(FLS), Genetic Algorithms (GA) and Hybrid Computational Intelligence (HCI) in fault diagnosis[16]. Zhenyou
Zhang et al., used WPD, FFT and BP neural network for fault diagnosis and prognosis. The analysis was
focused on the vibration signals collected from sensors mounted on the critical component. The features
extracted from the frequency domain were used to train ANN. Trained ANN then predicted the degradation and
identified the faults of component[17]. Saravanan et al. 2008 used support vector machine (SVM) for fault
diagnosis of spur bevel gear box and this is a popular machine learning application due to its high accuracy and
good generalization capabilities[18]. Huang et al.(2008) used probability based Bayesian network methods to
identify vehicle fault which can be used to diagnose single-fault and multi-fault[19]. Zhixiong Li et al, usedthe
back propagation neural network (BPNN) and the radial-basis function neural network (RBFNN) to identify the
states of the gearbox.The numeric and experimental test results showed that the ANN classification method has
achieved high detection accuracy[20]. Weixiang Sun, Jin Chen and Jiaqing Li used data mining technology after
conventional fault testing.They proposed a new method based on C4.5 decision tree and principal component
9. Assessment of Gearbox Fault DetectionUsing Vibration Signal Analysis and Acoustic Emission
www.iosrjournals.org 60 | Page
analysis(PCA).It was found that compared to BPNN C4.5 extracts knowledge quickly from the testing and is
even superior to neural networks[21].
There are several other techniques like nearest neighbor method that classifies each record in a dataset
based on a combination of the classes of the k record(s) most similar to it in a historical dataset. Data
visualization is a visual interpretation of complex relationship in multidimensional data. It makes use of
graphics tools to illustrate data relationships. Yaguo Lei and Ming J. Zuo used a two stage feature selection and
weighting technique(TFSWT) via Eucledian distance evaluation technique(EDET) to select sensitive features
and remove fault unrelated features. They used a weighted K nearest neighbor(WKNN) classification algorithm
to identify the egar crack levels. The resolutionshowed that this method had higher identification accuracy[22].
VIII. CONCLUSION:
In this review paper the various types of defects related to gear boxes have been discussed. It was
clearly stated that vibration signature analysis and acoustic emission are two very efficient techniques for
early fault detection. Vibration signature analysis is used for detect major defects whereas acoustic analysis is
used to detect very minute cracks occurring in the gear box. Various signal processing techniques were
discussed. The importance of wavelet transformation has also been mentioned which is now a day‟s widely
used for feature extraction as waves associated to the gear boxes are non stationary nature. Various other
data mining techniques have been mentioned for a clear understanding of feature extraction. Relevant
research work carried out related to each have been discussed in brief.
REFERENCES
[1]. Assessment of Bearing Fault Detection Using Vibration Signal Analysis by Amit R. Bhende, GK Awari and SP Untawale
[2]. Sound and Vibration Measurement A/S,Bruel&Kjaer
[3]. Vibration-based fault diagnosis of spur bevel gear box using fuzzy techniqueN. Saravanan, S. Cholairajan, K.I. Ramachandran
[4]. A comparison of Acoustic Emission and Vibration on Bearing Fault Detection by Xiaoqin Liu, Xing Wu, Chang Liu.Faculty of
Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming, China.
[5]. Practical Machinery Vibration Analysis and Predictive Maintenance,(Scheffer and Gridhar)
[6]. Interpolation techniques for time domain averaging vibration of gear, Mechanical System and signal Processing(1989),Examination
of a technique for the early detection of failure in gears by signal processing of the time domain average of the meshing
vibration(1987) by P.D.McFadden
[7]. An acoustic method to predict tooth surface failure of in service gears by K.Umezawa.T.Ajima and H.Houjoh.
[8]. A comparative experimental study on the diagnostic and prognostic of acoustic emission,vibration and spectrometric oil
analysis(2005) by CheeKeongTan ,Phil Irving,DavidMba.
[9]. Application of Acoustic Emission to seeded gear fault detection (2005)by Tim Toutountzakis,CheeKeong Tan and David Mba.
[10]. Condition monitoring of worm gears (2012) by M.Elforjani,D.Mba,A,Sire and A.Muhammad.
[11]. An acoustic method to predict tooth surface failure of in servicegears(1982) by K.Umezawa,T.Ajima and H.Houjoh.
[12]. He, S., He, Z.,& Wang, G. (2011). Online monitoring and fault identification of mean shifts in bivariate processes using decision
tree learning techniques. Journal of Intelligent Manufacturing, 1–10. doi:10.1007/s10845-011-0533-5.
[13]. Kasabov, N. (2001). Evolving fuzzy neural networks for supervised/ unsupervised online knowledge-based learning.IEEE
Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics, 31, 902–918.
[14]. Markou, M., & Singh, S. (2003). Novelty detection: A review–part 2:Neural network based approaches. Signal Processing, 83,
2499–2521.
[15]. Marzi, H. (2004). Real-time fault detection and isolation in industrial machines using learning vector quantization. Proceedings of
the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 218, 949–959.
[16]. Wang, K. (2002). Intelligent condition monitoring and diagnosis systems.
[17]. Zhixiong Li, Xinping Yan, Chengqing Yuan, Jiangbin Zhao and ZhongxiaoPeng. Fault Detection and Diagnosis of a Gearbox in
Marine Propulsion Systems Using Bispectrum Analysis and Artificial Neural Networks.Article ID: 1671-9433(2011)01-0017-08
[18]. Saravanan, N. K., Sidddabattuni, V. N. S., &Ramachandran, K. I. (2008). A comparative study on classification of features by SVM
and PSVM extracted using Morlet wavelet for fault diagnosis of spur bevel gearbox. Expert System with Applications, 35, 1351–
1366
[19]. Huang, Y., Mcmurran, R., Dhadyalla, G., & Jones, R. P. (2008). Probabilitybased vehicle fault diagnosis: Bayesian networkmethod.
Journal of Intelligent Manufacturing, 19(3), 301–311.
[20]. Zhixiong Li, Xinping Yan, Chengqing Yuan, Jiangbin Zhao and ZhongxiaoPeng. Fault Detectionand Diagnosis of a Gearbox in
Marine Propulsion Systems Using Bispectrum Analysis and Artificial Neural Networks.Article ID: 1671-9433(2011)01-0017-08
[21]. Decision tree and PCA-based fault diagnosis of rotating machinery(2006) by Weixiang Sun, Jin Chen, Jiaqing Li.
[22]. Gear crack level identification based on weighted K nearest neighbor classification algorithm(2009) by YaguoLei, MingJ.Zuo