This document presents a mathematical model of ball bearing anomalies in induction machines. It begins with background on ball bearing failures accounting for around 50% of induction machine breakdowns. It then discusses modeling the kinematic frequencies of ball bearings and developing models to represent anomalies on the outer ring and inner ring. The outer ring anomaly is modeled as a series of radial pulses with a frequency equal to the ball rotation frequency around the outer ring. The inner ring anomaly is modeled in a reference frame rotating with the inner ring speed. The modeling aims to analyze the effects of anomalies on electrical and mechanical quantities of the machine and its stability during operation.
DESIGN AND DEVELOPMENT OF MACHINE FAULT SIMULATOR (MFS) FOR FAULT DIAGNOSISijmech
Recent years have seen the rise of vibration problems associated with structures, which are more delicate
and intricate, machines that are faster, more complex and production process that are automated and
interlinked. The occurred problems are directly related to demands of lower investment, running and
maintenance cost in incidence with the requirement of increase productivity and efficiency. This work
developed aMachine Fault Simulator (MFS),whichis the most comprehensive laboratory scale machine on
the market for performing rotor dynamics experiments.Also, it helps in learning vibration signature of the
most common machinery faults in a controlled manner without compromising your quality production/
profits. The bench top system has a spacious modular design featuring versatility, operational simplicity
and robustness in depth studies of a variety of faults can be conducted using over many applications. Some
examples are rolling element bearing defects, Gear defect, belt and pulley defect, motor bearing defect.
IRJET- Effect of Vibrations on Various Systems of Helicopter and its Maintena...IRJET Journal
This document summarizes a study that assessed the effect of vibration on helicopter subsystems, reliability, maintainability, and life-cycle costs. The study compared two groups of Indian Navy Advanced Light Helicopters (ALH/Dhruv) - one equipped with a rotor-mounted vibration absorber that reduces vibration, and one without the absorber. Analyses showed the helicopters with absorbers had a 48% lower failure rate, 38.5% lower corrective maintenance costs, and 10% lower life-cycle costs. At the subsystem level, most components also saw these reductions except some avionics. The results suggest reducing vibration can significantly improve reliability and reduce costs, and may extend the useful life of aircraft.
The document discusses modal analysis of a high-speed milling spindle. A finite element model of the spindle is created in ANSYS based on its specifications. Modal analysis of the model yields natural frequencies including 422 Hz. Experimental modal analysis using an FFT analyzer on a manufactured spindle specimen yields frequencies up to 401 Hz. Comparing the finite element and experimental results, 422 Hz is identified as the natural resonance frequency of the spindle, which is above the designed operating speed of 16,000 rpm. The modal analysis shows no resonance will occur during operation.
Theoretical and Software Based Comparison of Cantilever Beam: MODAL ANALYSISAM Publications
Modal analysis is a process of describing a structure in terms of its natural characteristics which are the
natural frequency and mode shape it's a dynamic property [1]. The change of modal characteristic directly provides force
excitation of structure condition based on change in frequency and mode shape of vibration. This paper presents results
of a theoretical modal analysis of beam made with different materials such as aluminium and mild steel. The beams
were excited assign impact hammer excitation frequency response functions (FRFS) were obtained using lab
view.(Signal Express). The FRFS were processed using signal express to identify the natural frequency and mode safe
of aluminium and mild steel beam.
This document presents analytical equations for rotational balancing of machines. It begins by introducing rotational unbalance as an uneven mass distribution that causes vibration. Single plane balancing with one unbalanced mass is modeled using reaction forces and moments. Equations are derived to calculate the magnitude and location of an unbalance based on measured forces. Double plane balancing, with unbalances in two planes, is more complex and the document presents novel equations to solve it analytically rather than through graphical methods. The equations were tested on examples from textbooks. The goal is to provide a simpler analytical approach to rotational balancing compared to existing graphical techniques.
Computer Science
Active and Programmable Networks
Active safety systems
Ad Hoc & Sensor Network
Ad hoc networks for pervasive communications
Adaptive, autonomic and context-aware computing
Advance Computing technology and their application
Advanced Computing Architectures and New Programming Models
Advanced control and measurement
Aeronautical Engineering,
Agent-based middleware
Alert applications
Automotive, marine and aero-space control and all other control applications
Autonomic and self-managing middleware
Autonomous vehicle
Biochemistry
Bioinformatics
BioTechnology(Chemistry, Mathematics, Statistics, Geology)
Broadband and intelligent networks
Broadband wireless technologies
CAD/CAM/CAT/CIM
Call admission and flow/congestion control
Capacity planning and dimensioning
Changing Access to Patient Information
Channel capacity modelling and analysis
Civil Engineering,
Cloud Computing and Applications
Collaborative applications
Communication application
Communication architectures for pervasive computing
Communication systems
Computational intelligence
Computer and microprocessor-based control
Computer Architecture and Embedded Systems
Computer Business
Computer Sciences and Applications
Computer Vision
Computer-based information systems in health care
Computing Ethics
Computing Practices & Applications
Congestion and/or Flow Control
Content Distribution
Context-awareness and middleware
Creativity in Internet management and retailing
Cross-layer design and Physical layer based issue
Cryptography
Data Base Management
Data fusion
Data Mining
Data retrieval
Data Storage Management
Decision analysis methods
Decision making
Digital Economy and Digital Divide
Digital signal processing theory
Distributed Sensor Networks
Drives automation
Drug Design,
Drug Development
DSP implementation
E-Business
E-Commerce
E-Government
Electronic transceiver device for Retail Marketing Industries
Electronics Engineering,
Embeded Computer System
Emerging advances in business and its applications
Emerging signal processing areas
Enabling technologies for pervasive systems
Energy-efficient and green pervasive computing
Environmental Engineering,
Estimation and identification techniques
Evaluation techniques for middleware solutions
Event-based, publish/subscribe, and message-oriented middleware
Evolutionary computing and intelligent systems
Expert approaches
Facilities planning and management
Flexible manufacturing systems
Formal methods and tools for designing
Fuzzy algorithms
Fuzzy logics
GPS and location-based app
This document provides guidance on ergonomic design principles for navigation bridges. It discusses general design considerations like defining roles, designing for human capabilities and limitations, arranging displays and controls for accessibility and usability. It also provides specific guidance on bridge functionality, arrangement, console design, display and control integration, alarm design, procedures, job aids, and the work environment regarding vibration, noise, lighting, temperature and more. The goal is to apply ergonomic data to bridge design to support safe and efficient bridge operations.
Final Year Project Report Sample for Engineers - IIT and State UniversityHitesh Sharma
A sample report for all final year college students, for Engineering and Management Branch.
Best for Mechanical and Core branch students.
Includes - First Page, Index Style, Abstract, Body, COnsclusion and Designing Methods.
Share and Support this file, thanks and also fo for my other uploads.
DESIGN AND DEVELOPMENT OF MACHINE FAULT SIMULATOR (MFS) FOR FAULT DIAGNOSISijmech
Recent years have seen the rise of vibration problems associated with structures, which are more delicate
and intricate, machines that are faster, more complex and production process that are automated and
interlinked. The occurred problems are directly related to demands of lower investment, running and
maintenance cost in incidence with the requirement of increase productivity and efficiency. This work
developed aMachine Fault Simulator (MFS),whichis the most comprehensive laboratory scale machine on
the market for performing rotor dynamics experiments.Also, it helps in learning vibration signature of the
most common machinery faults in a controlled manner without compromising your quality production/
profits. The bench top system has a spacious modular design featuring versatility, operational simplicity
and robustness in depth studies of a variety of faults can be conducted using over many applications. Some
examples are rolling element bearing defects, Gear defect, belt and pulley defect, motor bearing defect.
IRJET- Effect of Vibrations on Various Systems of Helicopter and its Maintena...IRJET Journal
This document summarizes a study that assessed the effect of vibration on helicopter subsystems, reliability, maintainability, and life-cycle costs. The study compared two groups of Indian Navy Advanced Light Helicopters (ALH/Dhruv) - one equipped with a rotor-mounted vibration absorber that reduces vibration, and one without the absorber. Analyses showed the helicopters with absorbers had a 48% lower failure rate, 38.5% lower corrective maintenance costs, and 10% lower life-cycle costs. At the subsystem level, most components also saw these reductions except some avionics. The results suggest reducing vibration can significantly improve reliability and reduce costs, and may extend the useful life of aircraft.
The document discusses modal analysis of a high-speed milling spindle. A finite element model of the spindle is created in ANSYS based on its specifications. Modal analysis of the model yields natural frequencies including 422 Hz. Experimental modal analysis using an FFT analyzer on a manufactured spindle specimen yields frequencies up to 401 Hz. Comparing the finite element and experimental results, 422 Hz is identified as the natural resonance frequency of the spindle, which is above the designed operating speed of 16,000 rpm. The modal analysis shows no resonance will occur during operation.
Theoretical and Software Based Comparison of Cantilever Beam: MODAL ANALYSISAM Publications
Modal analysis is a process of describing a structure in terms of its natural characteristics which are the
natural frequency and mode shape it's a dynamic property [1]. The change of modal characteristic directly provides force
excitation of structure condition based on change in frequency and mode shape of vibration. This paper presents results
of a theoretical modal analysis of beam made with different materials such as aluminium and mild steel. The beams
were excited assign impact hammer excitation frequency response functions (FRFS) were obtained using lab
view.(Signal Express). The FRFS were processed using signal express to identify the natural frequency and mode safe
of aluminium and mild steel beam.
This document presents analytical equations for rotational balancing of machines. It begins by introducing rotational unbalance as an uneven mass distribution that causes vibration. Single plane balancing with one unbalanced mass is modeled using reaction forces and moments. Equations are derived to calculate the magnitude and location of an unbalance based on measured forces. Double plane balancing, with unbalances in two planes, is more complex and the document presents novel equations to solve it analytically rather than through graphical methods. The equations were tested on examples from textbooks. The goal is to provide a simpler analytical approach to rotational balancing compared to existing graphical techniques.
Computer Science
Active and Programmable Networks
Active safety systems
Ad Hoc & Sensor Network
Ad hoc networks for pervasive communications
Adaptive, autonomic and context-aware computing
Advance Computing technology and their application
Advanced Computing Architectures and New Programming Models
Advanced control and measurement
Aeronautical Engineering,
Agent-based middleware
Alert applications
Automotive, marine and aero-space control and all other control applications
Autonomic and self-managing middleware
Autonomous vehicle
Biochemistry
Bioinformatics
BioTechnology(Chemistry, Mathematics, Statistics, Geology)
Broadband and intelligent networks
Broadband wireless technologies
CAD/CAM/CAT/CIM
Call admission and flow/congestion control
Capacity planning and dimensioning
Changing Access to Patient Information
Channel capacity modelling and analysis
Civil Engineering,
Cloud Computing and Applications
Collaborative applications
Communication application
Communication architectures for pervasive computing
Communication systems
Computational intelligence
Computer and microprocessor-based control
Computer Architecture and Embedded Systems
Computer Business
Computer Sciences and Applications
Computer Vision
Computer-based information systems in health care
Computing Ethics
Computing Practices & Applications
Congestion and/or Flow Control
Content Distribution
Context-awareness and middleware
Creativity in Internet management and retailing
Cross-layer design and Physical layer based issue
Cryptography
Data Base Management
Data fusion
Data Mining
Data retrieval
Data Storage Management
Decision analysis methods
Decision making
Digital Economy and Digital Divide
Digital signal processing theory
Distributed Sensor Networks
Drives automation
Drug Design,
Drug Development
DSP implementation
E-Business
E-Commerce
E-Government
Electronic transceiver device for Retail Marketing Industries
Electronics Engineering,
Embeded Computer System
Emerging advances in business and its applications
Emerging signal processing areas
Enabling technologies for pervasive systems
Energy-efficient and green pervasive computing
Environmental Engineering,
Estimation and identification techniques
Evaluation techniques for middleware solutions
Event-based, publish/subscribe, and message-oriented middleware
Evolutionary computing and intelligent systems
Expert approaches
Facilities planning and management
Flexible manufacturing systems
Formal methods and tools for designing
Fuzzy algorithms
Fuzzy logics
GPS and location-based app
This document provides guidance on ergonomic design principles for navigation bridges. It discusses general design considerations like defining roles, designing for human capabilities and limitations, arranging displays and controls for accessibility and usability. It also provides specific guidance on bridge functionality, arrangement, console design, display and control integration, alarm design, procedures, job aids, and the work environment regarding vibration, noise, lighting, temperature and more. The goal is to apply ergonomic data to bridge design to support safe and efficient bridge operations.
Final Year Project Report Sample for Engineers - IIT and State UniversityHitesh Sharma
A sample report for all final year college students, for Engineering and Management Branch.
Best for Mechanical and Core branch students.
Includes - First Page, Index Style, Abstract, Body, COnsclusion and Designing Methods.
Share and Support this file, thanks and also fo for my other uploads.
Fabrication and Analysis of Fatigue Testing Machinetheijes
The document describes the fabrication and analysis of a fatigue testing machine. Key points:
- The machine subjects material specimens to repeated cyclic loading to determine their fatigue strength and create S-N curves.
- Components include a motor, bearings, frame, testing specimens of mild steel and stainless steel, a sensor, and digital counter.
- Testing of the materials generated S-N curves and estimated their endurance limits, which were within 20% of actual values.
- The design provides an affordable way to experimentally determine fatigue properties of materials through cyclic loading tests.
Detection of Static Air-Gap Eccentricity in Three Phase induction Motor by Us...IJERA Editor
This paper presents the effect of the static air-gap eccentricity on the performance of a three phase induction motor .The Artificial Neural Network (ANN) approach has been used to detect this fault .This technique depends upon the amplitude of the positive and negative harmonics of the frequency. Two motors of (2.2 Kw) have been used to achieve the actual fault and desirable data at no-load, half-load and full-load conditions. Motor Current Signature analysis (MCSA) based on stator current has been used to detect eccentricity fault. Feed forward neural network and error back propagation training algorithms are used to perform the motor fault detection. The inputs of artificial neural network are the amplitudes of the positive and negative harmonics and the speed, and the output is the type of fault. The training of neural network is achieved by data through the experiments test on healthy and faulty motor and the diagnostic system can discriminate between “healthy” and “faulty” machine.
The document summarizes a project to design a welding fixture with active positioning functions. It provides background on robotic welding, benefits over manual welding. It discusses HUST's current fixture which allows only 1 degree of freedom. The project aims to give the fixture increased versatility with 2 degrees of freedom to weld more complex parts without repositioning. Background research covered the history of robotics, benefits of automated manufacturing and welding. Current solutions were examined, including adaptive fixturing and robot controllers.
1. The document describes the design of an automobile gearbox holding device to safely remove and replace gearboxes during maintenance.
2. Currently, mechanics use dangerous methods involving multiple men lying under vehicles to support heavy gearboxes by hand, risking injury.
3. The proposed design uses a linked mechanism with a support plate, power screw, brackets, and links to lift and lower the gearbox. Rotating the power screw causes the support plate to move up and down.
4. Calculations were done to design the plate, screw, and links to withstand the required loads while keeping stresses below safe limits. The design aims to minimize risks for mechanics and be reliable, efficient, and cost-effective.
IRJET- Investigation into use of Soft Robotic End Effector for Assistive ...IRJET Journal
1) Researchers designed and fabricated a soft robotic end effector using pneumatic networks (PneuNets) for use as a low-cost assistive gripping prosthesis.
2) PneuNets made of elastomers and pressurized air channels allow for compliant finger motion similar to human hands. The researchers 3D printed molds and cast silicone fingers connected by tubes to an air supply.
3) Finite element simulations and experiments showed the fingers could grip objects through varying air pressure. Flex sensors on the prototype provided partial electronic control of grip strength. Higher air flow could improve bending range.
Modeling and Control of a Spherical Rolling Robot Using Model Reference Adapt...IRJET Journal
The document describes modeling and control of a spherical rolling robot using model reference adaptive control (MRAC). It presents the mathematical model developed for the robot based on its nonholonomic constraints. MRAC is used to control the robot by adjusting controller parameters to minimize the error between the robot's actual output and the output of a reference model for ideal behavior. Simulation results show the proposed MRAC scheme eliminates steady state error and improves transient response without requiring knowledge of the robot's dynamic equations.
This document discusses the effects of wind and seismic loading on spires through finite element analysis. It summarizes the modeling and analysis of a 100m steel spire with varying diameters. Modal analysis was conducted in ETABS to determine natural frequencies and mode shapes, which were validated against empirical calculations. The spire was then analyzed under wind loads according to different wind zones and seismic loads for Zone V. Results showed shear forces and bending moments decreased with height and wind speed, with seismic loads being much lower. Stresses were found to be within permissible limits. While the spire was found safe under wind loads, further fatigue analysis is needed due to failures of similar structures from fatigue in the past.
This document presents a method called Hybrid Linearization Method for de-noising electrocardiogram (ECG) signals. The method combines Extended Kalman Filtering (EKF) with Discrete Wavelet Transform (DWT). EKF is first used to de-noise the ECG signal and reduce noise, but DWT is then applied to further improve the quality of the de-noised signal. The algorithm and steps are described. Results show that the proposed Hybrid Linearization Method achieves a lower root mean square error than EKF alone, demonstrating its effectiveness at de-noising ECG signals.
Effect of Different Levels of Cadmium, Lead and Arsenic on the Growth Perform...IOSR Journals
This document summarizes a study on the effects of different levels of cadmium, lead, and arsenic on the growth performance of broiler and layer chickens. Sixteen one-day-old chicks were fed feeds mixed with 0ppm, 10ppm, 20ppm, or 30ppm of the heavy metals. Results showed heavy metal accumulation in organs increased with concentration. Body weights decreased remarkably as metal concentrations increased, with 30ppm chickens weighing 820-1100g versus 1800-2350g for 0ppm at 56 days. Feed intake also decreased with higher metal levels. The study concludes that increasing heavy metal concentrations in poultry feed can retard growth rates and body weights.
Synthesis of Bismuth Ferrite nano particles by sol-gel method and their chara...IOSR Journals
This document describes a study that synthesized bismuth ferrite (BiFeO3) nanoparticles using a sol-gel method. X-ray diffraction and transmission electron microscopy were used to characterize the nanoparticles. XRD analysis before and after calcination showed crystalline BiFeO3 peaks and some impurity peaks. TEM revealed nanoparticles around 200 nm in size. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles. The sol-gel synthesis produced phase-pure BiFeO3 nanoparticles without requiring high temperature treatment.
This document proposes a universal algorithm for stage switching in hypercube interconnection networks used in multi-core systems. It analyzes a 4-stage 16x16 hypercube network and derives a switching algorithm where the selection bit sequence changes at each stage in a predefined manner. This algorithm is then generalized for an n-stage hypercube network to establish relationships between the selection bit patterns at different stages. The proposed universal algorithm could be used for linear switching in hypercube networks of any size to efficiently design higher order interconnection blocks for multi-core systems.
The document summarizes a study on the effect of imbalance on the performance of an unpaced five-station production line. The study considers a situation where five operation times with exponentially distributed times are assigned to five stations. This results in 60 different assignments. The effect of assignment ordering on production rate is studied by calculating the percent improvement possible from the best ordering over the worst. At moderate imbalance degrees, the effect is found to be highly significant. A mathematical model of the production line is developed using exponential distribution assumptions and steady-state probabilities to analyze different system states and calculate production rates for different orderings.
This document discusses improving the performance of a microstrip antenna using a fractal electronic band gap (EBG) structure and vias. A fractal EBG unit cell design is presented using a square shape with nested smaller squares. Microstrip antennas were designed with and without this EBG structure, and with and without vias connecting the EBG patches to the ground plane. Measurements showed the bandwidth and S11 were improved, back radiation was reduced, and directivity was increased for the antenna with both the EBG structure and vias compared to designs without them. Specifically, bandwidth increased by 1.125% and S11 decreased by 4.188dB with the EBG structure and vias.
Dynamic Programming approach in Two Echelon Inventory System with Repairable ...IOSR Journals
This document presents a two-echelon inventory system model with repairable items. The system consists of operating sites (base stations) and a depot. Each base station has inventory to fulfill failed item demands and is replenished from the depot. Failed items arrive at base stations according to a Poisson process and are inspected. Inspection times are exponential. Inspected items are either repaired at the depot or condemned. The system aims to determine optimal ordering policies to minimize average costs using Markov decision processes and dynamic programming. Numerical examples are provided to illustrate the model.
This document discusses a study examining how beliefs held by caregivers influence help-seeking behavior in the treatment of mental illness in Nakuru municipality, Kenya. The study found that most caregivers believed traditional healers did not understand the causes of mental illness or have good counseling skills. They also believed traditional healers were not humane, did not have time for patients, and were too expensive. However, some caregivers still sought traditional treatment. The study recommends public education programs to provide knowledge on mental illness and demystify related beliefs. It also suggests replicating the study in other parts of Nakuru County and other Kenyan counties.
This document provides a survey of the Internet of Things (IoT). It defines IoT from different perspectives such as things, internet, and semantics. Key enabling technologies for IoT include RFID, sensor networks, and intelligence in smart objects. Potential applications discussed are supply chain management, transportation, healthcare, and disaster alerting/recovery. Major open issues remaining are the need for further standardization and addressing security/privacy concerns as IoT becomes more pervasive.
This document proposes a key-aggregate encryption scheme called Input Cumulative Cryptosystem for secure and scalable data sharing in cloud computing. The scheme allows a data owner to generate a constant-size aggregate decryption key that can decrypt multiple ciphertexts. The key has the combined decryption power of all individual secret keys. An intrusion detection system also monitors communication between hosts to only allow data sharing between trusted hosts, improving security. The proposed system aims to address issues with existing approaches that require distributing multiple decryption keys or have fixed hierarchies for access control. It allows flexible delegation of decryption rights for dynamic sets of ciphertexts in cloud storage.
This document summarizes the design of a single edge triggered D flip flop using the Gate Diffusion Input (GDI) technique to reduce power consumption. GDI allows implementing logic functions using fewer transistors which can reduce power and delay. The proposed D flip flop uses a master-slave configuration with 4 GDI cells and samples data on the falling clock edge. Simulation results for a 180nm process show the GDI design uses 18 transistors, has average power of 1.77uw and maximum delay of 5.48ps, providing power reductions of 40% over conventional designs. Therefore, the GDI technique is suitable for low power applications requiring high performance.
1) A synthetic pseudo-source rock was prepared by depositing clay through an oil column to test for pseudo-source rock characteristics.
2) The synthetic rock showed good source rock potential through pyrolysis and biomarker analysis, matching the oil it was deposited with.
3) However, the rock was not mature enough on its own to generate hydrocarbons, showing it is a pseudo-source rock rather than a true source rock, as the kerogen incorporated was already mature rather than the rock itself reaching maturity.
This document discusses a real-time moving object detection algorithm using Speeded Up Robust Features (SURF). The algorithm first uses SURF to extract features from video frames and stitch them together to create a single background image. It then takes the difference between each video frame and the background image to detect moving objects. Experimental results show it can effectively detect moving objects in videos from both stable and moving cameras, outperforming traditional background subtraction techniques. The algorithm solves issues with modeling changing backgrounds in real-time by creating a static background image using frame registration with SURF.
This document presents a digital image watermarking technique using Hadamard transform. The key steps are:
1. The image is divided into 8x8 blocks and Hadamard transform applied to get coefficients. Breadth-first search is used to select efficient embedding points among the positive coefficients.
2. Prime numbered blocks are avoided for embedding. Two points in the first column are selected for embedding the watermark.
3. Cox's equation is used to embed the watermark in the host image coefficients. Inverse Hadamard transform generates the watermarked image.
4. To extract the watermark, the process is reversed using the visited matrix of points. Experiments show the technique provides better image
The document discusses precision controlled privacy preservation in relational data. It proposes a multilevel anonymization technique that combines generalization and suppression to provide improved security and minimum precision in retrieved data compared to previous methods. An experimental evaluation on a medical dataset shows the proposed method retrieves more tuples than previous privacy preserving access control and workload-aware anonymization methods, especially with increasing numbers of query predicates. The aim is to satisfy accuracy constraints for authorized data retrieval while preserving privacy through this combined anonymization approach.
Fabrication and Analysis of Fatigue Testing Machinetheijes
The document describes the fabrication and analysis of a fatigue testing machine. Key points:
- The machine subjects material specimens to repeated cyclic loading to determine their fatigue strength and create S-N curves.
- Components include a motor, bearings, frame, testing specimens of mild steel and stainless steel, a sensor, and digital counter.
- Testing of the materials generated S-N curves and estimated their endurance limits, which were within 20% of actual values.
- The design provides an affordable way to experimentally determine fatigue properties of materials through cyclic loading tests.
Detection of Static Air-Gap Eccentricity in Three Phase induction Motor by Us...IJERA Editor
This paper presents the effect of the static air-gap eccentricity on the performance of a three phase induction motor .The Artificial Neural Network (ANN) approach has been used to detect this fault .This technique depends upon the amplitude of the positive and negative harmonics of the frequency. Two motors of (2.2 Kw) have been used to achieve the actual fault and desirable data at no-load, half-load and full-load conditions. Motor Current Signature analysis (MCSA) based on stator current has been used to detect eccentricity fault. Feed forward neural network and error back propagation training algorithms are used to perform the motor fault detection. The inputs of artificial neural network are the amplitudes of the positive and negative harmonics and the speed, and the output is the type of fault. The training of neural network is achieved by data through the experiments test on healthy and faulty motor and the diagnostic system can discriminate between “healthy” and “faulty” machine.
The document summarizes a project to design a welding fixture with active positioning functions. It provides background on robotic welding, benefits over manual welding. It discusses HUST's current fixture which allows only 1 degree of freedom. The project aims to give the fixture increased versatility with 2 degrees of freedom to weld more complex parts without repositioning. Background research covered the history of robotics, benefits of automated manufacturing and welding. Current solutions were examined, including adaptive fixturing and robot controllers.
1. The document describes the design of an automobile gearbox holding device to safely remove and replace gearboxes during maintenance.
2. Currently, mechanics use dangerous methods involving multiple men lying under vehicles to support heavy gearboxes by hand, risking injury.
3. The proposed design uses a linked mechanism with a support plate, power screw, brackets, and links to lift and lower the gearbox. Rotating the power screw causes the support plate to move up and down.
4. Calculations were done to design the plate, screw, and links to withstand the required loads while keeping stresses below safe limits. The design aims to minimize risks for mechanics and be reliable, efficient, and cost-effective.
IRJET- Investigation into use of Soft Robotic End Effector for Assistive ...IRJET Journal
1) Researchers designed and fabricated a soft robotic end effector using pneumatic networks (PneuNets) for use as a low-cost assistive gripping prosthesis.
2) PneuNets made of elastomers and pressurized air channels allow for compliant finger motion similar to human hands. The researchers 3D printed molds and cast silicone fingers connected by tubes to an air supply.
3) Finite element simulations and experiments showed the fingers could grip objects through varying air pressure. Flex sensors on the prototype provided partial electronic control of grip strength. Higher air flow could improve bending range.
Modeling and Control of a Spherical Rolling Robot Using Model Reference Adapt...IRJET Journal
The document describes modeling and control of a spherical rolling robot using model reference adaptive control (MRAC). It presents the mathematical model developed for the robot based on its nonholonomic constraints. MRAC is used to control the robot by adjusting controller parameters to minimize the error between the robot's actual output and the output of a reference model for ideal behavior. Simulation results show the proposed MRAC scheme eliminates steady state error and improves transient response without requiring knowledge of the robot's dynamic equations.
This document discusses the effects of wind and seismic loading on spires through finite element analysis. It summarizes the modeling and analysis of a 100m steel spire with varying diameters. Modal analysis was conducted in ETABS to determine natural frequencies and mode shapes, which were validated against empirical calculations. The spire was then analyzed under wind loads according to different wind zones and seismic loads for Zone V. Results showed shear forces and bending moments decreased with height and wind speed, with seismic loads being much lower. Stresses were found to be within permissible limits. While the spire was found safe under wind loads, further fatigue analysis is needed due to failures of similar structures from fatigue in the past.
This document presents a method called Hybrid Linearization Method for de-noising electrocardiogram (ECG) signals. The method combines Extended Kalman Filtering (EKF) with Discrete Wavelet Transform (DWT). EKF is first used to de-noise the ECG signal and reduce noise, but DWT is then applied to further improve the quality of the de-noised signal. The algorithm and steps are described. Results show that the proposed Hybrid Linearization Method achieves a lower root mean square error than EKF alone, demonstrating its effectiveness at de-noising ECG signals.
Effect of Different Levels of Cadmium, Lead and Arsenic on the Growth Perform...IOSR Journals
This document summarizes a study on the effects of different levels of cadmium, lead, and arsenic on the growth performance of broiler and layer chickens. Sixteen one-day-old chicks were fed feeds mixed with 0ppm, 10ppm, 20ppm, or 30ppm of the heavy metals. Results showed heavy metal accumulation in organs increased with concentration. Body weights decreased remarkably as metal concentrations increased, with 30ppm chickens weighing 820-1100g versus 1800-2350g for 0ppm at 56 days. Feed intake also decreased with higher metal levels. The study concludes that increasing heavy metal concentrations in poultry feed can retard growth rates and body weights.
Synthesis of Bismuth Ferrite nano particles by sol-gel method and their chara...IOSR Journals
This document describes a study that synthesized bismuth ferrite (BiFeO3) nanoparticles using a sol-gel method. X-ray diffraction and transmission electron microscopy were used to characterize the nanoparticles. XRD analysis before and after calcination showed crystalline BiFeO3 peaks and some impurity peaks. TEM revealed nanoparticles around 200 nm in size. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles. The sol-gel synthesis produced phase-pure BiFeO3 nanoparticles without requiring high temperature treatment.
This document proposes a universal algorithm for stage switching in hypercube interconnection networks used in multi-core systems. It analyzes a 4-stage 16x16 hypercube network and derives a switching algorithm where the selection bit sequence changes at each stage in a predefined manner. This algorithm is then generalized for an n-stage hypercube network to establish relationships between the selection bit patterns at different stages. The proposed universal algorithm could be used for linear switching in hypercube networks of any size to efficiently design higher order interconnection blocks for multi-core systems.
The document summarizes a study on the effect of imbalance on the performance of an unpaced five-station production line. The study considers a situation where five operation times with exponentially distributed times are assigned to five stations. This results in 60 different assignments. The effect of assignment ordering on production rate is studied by calculating the percent improvement possible from the best ordering over the worst. At moderate imbalance degrees, the effect is found to be highly significant. A mathematical model of the production line is developed using exponential distribution assumptions and steady-state probabilities to analyze different system states and calculate production rates for different orderings.
This document discusses improving the performance of a microstrip antenna using a fractal electronic band gap (EBG) structure and vias. A fractal EBG unit cell design is presented using a square shape with nested smaller squares. Microstrip antennas were designed with and without this EBG structure, and with and without vias connecting the EBG patches to the ground plane. Measurements showed the bandwidth and S11 were improved, back radiation was reduced, and directivity was increased for the antenna with both the EBG structure and vias compared to designs without them. Specifically, bandwidth increased by 1.125% and S11 decreased by 4.188dB with the EBG structure and vias.
Dynamic Programming approach in Two Echelon Inventory System with Repairable ...IOSR Journals
This document presents a two-echelon inventory system model with repairable items. The system consists of operating sites (base stations) and a depot. Each base station has inventory to fulfill failed item demands and is replenished from the depot. Failed items arrive at base stations according to a Poisson process and are inspected. Inspection times are exponential. Inspected items are either repaired at the depot or condemned. The system aims to determine optimal ordering policies to minimize average costs using Markov decision processes and dynamic programming. Numerical examples are provided to illustrate the model.
This document discusses a study examining how beliefs held by caregivers influence help-seeking behavior in the treatment of mental illness in Nakuru municipality, Kenya. The study found that most caregivers believed traditional healers did not understand the causes of mental illness or have good counseling skills. They also believed traditional healers were not humane, did not have time for patients, and were too expensive. However, some caregivers still sought traditional treatment. The study recommends public education programs to provide knowledge on mental illness and demystify related beliefs. It also suggests replicating the study in other parts of Nakuru County and other Kenyan counties.
This document provides a survey of the Internet of Things (IoT). It defines IoT from different perspectives such as things, internet, and semantics. Key enabling technologies for IoT include RFID, sensor networks, and intelligence in smart objects. Potential applications discussed are supply chain management, transportation, healthcare, and disaster alerting/recovery. Major open issues remaining are the need for further standardization and addressing security/privacy concerns as IoT becomes more pervasive.
This document proposes a key-aggregate encryption scheme called Input Cumulative Cryptosystem for secure and scalable data sharing in cloud computing. The scheme allows a data owner to generate a constant-size aggregate decryption key that can decrypt multiple ciphertexts. The key has the combined decryption power of all individual secret keys. An intrusion detection system also monitors communication between hosts to only allow data sharing between trusted hosts, improving security. The proposed system aims to address issues with existing approaches that require distributing multiple decryption keys or have fixed hierarchies for access control. It allows flexible delegation of decryption rights for dynamic sets of ciphertexts in cloud storage.
This document summarizes the design of a single edge triggered D flip flop using the Gate Diffusion Input (GDI) technique to reduce power consumption. GDI allows implementing logic functions using fewer transistors which can reduce power and delay. The proposed D flip flop uses a master-slave configuration with 4 GDI cells and samples data on the falling clock edge. Simulation results for a 180nm process show the GDI design uses 18 transistors, has average power of 1.77uw and maximum delay of 5.48ps, providing power reductions of 40% over conventional designs. Therefore, the GDI technique is suitable for low power applications requiring high performance.
1) A synthetic pseudo-source rock was prepared by depositing clay through an oil column to test for pseudo-source rock characteristics.
2) The synthetic rock showed good source rock potential through pyrolysis and biomarker analysis, matching the oil it was deposited with.
3) However, the rock was not mature enough on its own to generate hydrocarbons, showing it is a pseudo-source rock rather than a true source rock, as the kerogen incorporated was already mature rather than the rock itself reaching maturity.
This document discusses a real-time moving object detection algorithm using Speeded Up Robust Features (SURF). The algorithm first uses SURF to extract features from video frames and stitch them together to create a single background image. It then takes the difference between each video frame and the background image to detect moving objects. Experimental results show it can effectively detect moving objects in videos from both stable and moving cameras, outperforming traditional background subtraction techniques. The algorithm solves issues with modeling changing backgrounds in real-time by creating a static background image using frame registration with SURF.
This document presents a digital image watermarking technique using Hadamard transform. The key steps are:
1. The image is divided into 8x8 blocks and Hadamard transform applied to get coefficients. Breadth-first search is used to select efficient embedding points among the positive coefficients.
2. Prime numbered blocks are avoided for embedding. Two points in the first column are selected for embedding the watermark.
3. Cox's equation is used to embed the watermark in the host image coefficients. Inverse Hadamard transform generates the watermarked image.
4. To extract the watermark, the process is reversed using the visited matrix of points. Experiments show the technique provides better image
The document discusses precision controlled privacy preservation in relational data. It proposes a multilevel anonymization technique that combines generalization and suppression to provide improved security and minimum precision in retrieved data compared to previous methods. An experimental evaluation on a medical dataset shows the proposed method retrieves more tuples than previous privacy preserving access control and workload-aware anonymization methods, especially with increasing numbers of query predicates. The aim is to satisfy accuracy constraints for authorized data retrieval while preserving privacy through this combined anonymization approach.
DSNs & X.400 assist in ensuring email reliabilityIOSR Journals
This document summarizes tools that help ensure email reliability by automatically responding to reports of undeliverability. It describes how Delivery Status Notifications (DSNs) and concepts from the X.400 protocol allow email sending software to persist in retransmitting messages or sending them to alternate recipients if the initial delivery fails or there is a report of non-delivery. The document provides background on how SMTP addresses reliability challenges and discusses implementations of active source responses, such as retransmitting messages later or to different addresses, to improve email delivery.
This document analyzes irrigation distribution networks using demand-driven analysis (DDA) and pressure-driven analysis (PDA). It summarizes the key differences between the two approaches and the results of applying each to a case study network. DDA uses fixed demands regardless of pressure, while PDA accounts for how demand varies with pressure based on sprinkler characteristics. The document finds that PDA yields higher minimum pressures and less variation across demand groups. It also allows evaluating how demands are influenced by pressure changes. Overall, PDA provides a better representation of real network operation compared to DDA.
The document discusses the utilization of foundry waste sand in the preparation of concrete. It presents the results of experiments conducted to study the compressive strength, split tensile strength, and flexural strength of M20 and M25 grade concrete containing 0%, 10%, and 100% replacement of foundry waste sand in place of fine aggregate. The tests were conducted at curing periods of 7, 28, and 56 days. The results showed that 100% replacement of foundry waste sand can be used for M20 and M25 grade concrete based on the compressive strengths achieved at different curing periods being comparable to control mixes. Flexural and split tensile strengths were also found to be comparable between control mixes and those with foundry
This document provides a review of how fuzzy logic techniques can improve the efficiency of power system stability. It begins with an introduction to fuzzy logic and how it can model human reasoning to address uncertainty. It then discusses issues with conventional power system stabilizers (PSS) and how fuzzy logic controllers (FLC) can help address their limitations in dealing with nonlinear systems. The document outlines the basic components of an FLC and steps to design one. It reviews several studies that have applied FLCs to PSS and gas turbine control and found they provide better damping and robustness compared to conventional controllers. The conclusion is that fuzzy logic is an effective approach for controlling complex, nonlinear processes in power systems.
A Wavelet Based fault Detection of Induction Motor: A Reviewijsrd.com
This paper presents a review of the researches done on fault detection and tolerant control , main aim of the fault tolerant control and fault detection of induction motor is used the wavelet transform. Wavelet transform is much better tool for the fault diagnosis point of view and a overview of the wavelet types (continuous and discrete), machine faults detection methods and their validation. The software, generality of codes, one dimensional and two dimensional DWT and frequency characteristics components of healthy as well as faulty induction motor has explained. So Finally, stator short winding , shaft fault, bearing fault ,rotor broken bar and open winding are taken as a case study to show the better diagnosis of fault by using wavelet techniques.
IRJET - Vibration Analysis Technique for the Diagnosis of Bearing Housing Vib...IRJET Journal
This document summarizes a study on analyzing vibrations in a bearing housing made of different materials. The study used mild steel and Bakelite as housing materials for a 30205 taper roller bearing tested between 500-2500 RPM. Vibration signals were collected from the housings using an FFT analyzer. Results showed Bakelite housing had more uniform vibration patterns and lower amplitudes compared to mild steel across all speeds and axes. Bakelite demonstrated better damping of vibrations. The study concluded Bakelite is a more reliable housing material than mild steel for applications like offshore pumps due to its vibration damping and chemical resistivity properties.
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.
Detection of internal and external faults of single-phase induction motor usi...IJECEIAES
The main aim of this work is to analyze the input current waveform for a single-phase induction capacitor-run motor (SIMCR) to detect the faults. Internal and external faults were applied to the SIMCR and the current was measured. An armature (broken rotor bar) and bearing faults were applied to the SIMCR. A microcontroller was used to record the motor current signal and MATLAB software was used to analyze it with the different types of fault with varying load operations. Various values of the running capacitor were used to investigate the effect of these values on the wave-current shape. Total harmonic distortion (THD) for the voltage and current was measured. A deep demonstration of the experimental results was also provided for a better understanding of the mechanisms of bearing and armature faults (broken rotor bars) and the vibration was recorded. Spectral and power analyses revealed the difference in total harmonic distortion. The proposed method in this paper can be used in various industrial applications and this technique is quite cheap and helps most of the researchers and very effectual.
Impact of Bearing Vibration on yarn quality in Ring Frameiosrjce
IOSR Journal of Polymer and Textile Engineering (IOSR-JPTE) is ambitious to disseminate information and experience in education, practice and investigation between polimer, fibric and all the sciences involved in textile.
This document summarizes research on ultrasonic motors. It discusses how ultrasonic motors can be miniaturized for use in medical devices and robots. The researchers designed three types of ultrasonic motors with decreasing size down to 4mm long and 1.6mm diameter. The motors use a hollow cylindrical stator with piezoelectric plates to generate elliptical motion from two orthogonal bending modes. Finite element analysis was used to optimize the design. The motors' performance was characterized using a transient method measuring speed and calculating torque of a loaded rotor.
Active magnetic bearings used as exciters for rolling element bearing outer r...ISA Interchange
The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft location as an exciter to apply electromagnetic force to the system. We investigate a nonlinear bearing-pedestal system model with the outer race defect under the electromagnetic force. The nonlinear differential equations are integrated using the fourth-order Runge–Kutta algorithm. The simulation and experimental results show that the characteristic signal of outer race incipient defect is significantly amplified under the electromagnetic force through the AMBs, which is helpful to improve the diagnosis accuracy of rolling element bearing's incipient outer race defect.
IRJET- Review paper on Stator and Rotor Fault Diagnosis of 3-Phase Induct...IRJET Journal
This document reviews methods for diagnosing faults in 3-phase induction motors. It discusses the main types of faults including stator faults, rotor faults, bearing failures, eccentricity, and mechanical vibrations. Various techniques are presented for fault detection such as vibration analysis, current and voltage monitoring, temperature measurements, and spectral analysis. The review emphasizes the need for effective fault diagnosis methods to improve reliability and prevent catastrophic motor failures.
Condition Monitoring and Vibrational Analysis of Proposed Shaft through Exper...IJERA Editor
The document summarizes research on condition monitoring and vibrational analysis of rotating shafts. It discusses how vibration monitoring is an important technique for monitoring shaft health and diagnosing faults like cracks. The research aims to analyze shaft vibration frequencies using experimental and finite element analysis approaches. Accelerometers and fast Fourier transform analysis are used to measure vibrations and identify frequencies. The research seeks to minimize shaft vibration amplitudes to reduce noise and detect cracks in rotating shafts. Correlating experimental and simulation results can help optimize shaft design for durability and performance.
SELF-ALIGNED BEARING FAULT DETECTION USING VIBRATION SIGNALS ANALYZED BY SPEC...Journal For Research
Over the past decades there have been many major advances in the development of fault diagnosis of deep grove ball bearing and roller bearing had taken placed. in this paper an effort is made to study the performance of Self aligned ball bearings. Self-aligned ball bearings are widely used in industry from home appliances to aerospace industry. Proper functioning of these machine elements is extremely important in order to prevent catastrophic damages. It is therefore, important to monitor the condition of the bearings and to know the severity of the defects before they cause serious catastrophic damages. Hence, the study of vibrations generated by these defects plays an important role in quality inspection as well as for condition monitoring of the self-aligned ball bearing/machine element. This paper describes the vibration analysis technique to detect the defects in the self-aligned ball bearing. The Fast Fourier Transform (FFT) detected the frequencies of damage present during the vibration analysis of a ball bearing. This faults and their related frequency is simulated with MATLAB software.
Vibration analysis of lathe structrure due to gear defect using fem 02THANMAY JS
The document discusses vibration analysis of lathe structures due to gear defects using finite element modeling. It aims to analyze the effects of unbalanced forces generated by machine elements like spindles and gears on the lathe structure. Both frequency domain and time domain analyses will be conducted using FEM. Experiments will also be conducted to measure vibration velocities on critical points of a lathe for different spindle speeds using a vibration tester. The results of experimental and theoretical analyses will be discussed to monitor machine elements and understand the effects of vibration on the lathe structure.
THE EFFECTS OF BOLT PRELOAD ON VIBRATION AMPLITUDE OF GANTRY CNC ROUTERIAEME Publication
The joint properties significant affect on the dynamic performance and spindle
vibration of gantry CNC router structure. This paper presents the relationship
between the vibration amplitude of the spindle nose of a gantry CNC router and a bolt
pre-tightening force. The dynamic model from machine structures with bolt joints was
developed to consider the impact of a bolt pre-tightening force to spindle vibration of
CNC router structures and dynamic behavior. Based on the dynamic model, harmonic
analysis is conducted to specify the spindle nose’s displacement corresponding to the
different bolt pre-tightening force. The FE analysis results indicate that bolt pretightening
forces have great influence on the spindle nose vibration amplitude and
when the pre-tightening force of bolt joints was increased, the dynamic stiffness of the
spindle also increases while the vibration amplitude decreases. The accuracy and
effectiveness of the model have also been confirmed by experimental results. The
achieved result will enhance the rigidity, improve the vibration resistance of the
machine structure to improve the reliability as well as machining precision, and attain
the best surface quality
Fluid Structural Modal Coupled Numerical Investigation of Transonic Flutterin...IJERA Editor
Flutter is an unstable oscillation which can lead to destruction. Flutter can occur on fixed surfaces, such as blades, wing or the stabilizer. By self-excited aeroelastic instability, flutter can lead to mechanical or structural failure of aircraft engine blades. The modern engines have been designed with increased pressure ratio and reduced weight in order to improve aerodynamic efficiency, resulting in severe aeroelastic problems. Particularly flutter in axial compressors with transonic flow can be characterized by a number of aerodynamic nonlinear effects such as shock boundary layer interaction, rotating stall, and tip vortex instability. Rotating blades operating under high centrifugal forces may also encounter structural nonlinearities due to friction damping and large deformations. In the future work a standard axial flow compressor blade will be taken for analysis, both Subsonic and Transonic range are taken for analysis. Fluid and Structure are two different domains which will be coupled by full system coupling technique to predict the fluttering effect on the compressor blade. ANSYS is a commercial simulation tool, which will be deployed in this work to perform FSI (Fluid Structure Interaction) and FSI coupled Modal to predict the flutter in the compressor blades
Fluid Structural Modal Coupled Numerical Investigation of Transonic Flutterin...IJERA Editor
Flutter is an unstable oscillation which can lead to destruction. Flutter can occur on fixed surfaces, such as blades, wing or the stabilizer. By self-excited aeroelastic instability, flutter can lead to mechanical or structural failure of aircraft engine blades. The modern engines have been designed with increased pressure ratio and reduced weight in order to improve aerodynamic efficiency, resulting in severe aeroelastic problems. Particularly flutter in axial compressors with transonic flow can be characterized by a number of aerodynamic nonlinear effects such as shock boundary layer interaction, rotating stall, and tip vortex instability. Rotating blades operating under high centrifugal forces may also encounter structural nonlinearities due to friction damping and large deformations. In the future work a standard axial flow compressor blade will be taken for analysis, both Subsonic and Transonic range are taken for analysis. Fluid and Structure are two different domains which will be coupled by full system coupling technique to predict the fluttering effect on the compressor blade. ANSYS is a commercial simulation tool, which will be deployed in this work to perform FSI (Fluid Structure Interaction) and FSI coupled Modal to predict the flutter in the compressor blades
This document summarizes research on vibrations that occur during chip removal mechanical processing. It discusses the types of vibrations that can appear, including forced vibrations caused by external factors and self-excited vibrations caused by factors related to the cutting process itself. The document presents theories on modeling the vibratory movement of the cutting tool as an oscillating system. Equations are provided that describe the oscillation frequency, amplitude, phase angle, and amplitude ratio based on parameters like the cutting force, tool and workpiece geometry, and system stiffness. The energy consumed in maintaining vibratory movement is also analyzed. Causes of self-excited vibrations are explored, and how vibrations can affect surface quality is described.
Sensitivity Analysis on Variation of Vane Natural Frequency of a Typical Aero...IJERA Editor
Centrifugal compressors are widely used in small and medium class turbo shaft and turbo prop aero engines. Inevitably the variation in the manufacturing process will lead to variation in natural frequency of blade vanes in an impeller which usually termed as Mistuning. The variation in natural frequency will increase the forced frequency response of the vanes than the tuned vanes. In-service deterioration of vanes dimension due to erosion, corrosion and FOD also adds to further variation in natural frequency. The amplification factor of the response will lead to reduced HCF life of the vanes than the tuned vanes. It is important for the designer to envisage the variation of natural frequency of the vanes to estimate the life of the impeller to avoid premature failure. This also helps in monitoring the health of the impeller during service. This paper deals with prediction of the effects of manufacturing/geometry variation and variation in material properties on impeller vane natural frequency of a turbo shaft engine. FEM model is created to accommodate the geometry variation of the impeller. The parameters influencing the natural frequency are varied and its corresponding variation in frequency is predicted. Several conditions are also simulated and sensitivity analysis is carried out with the above result to predict the order of influencing parameters. Influencing parameters are ranked and the most influencing parameter is found to be the Young’s Modulus of the material for this case of impeller. Maximum influencing parameter Young’s modulus contributes to 5.8% variation and the least contributing factor density to 0.6% variation in natural frequency. This result enables the designer to forecast the possible range of natural frequencies in the design phase, so that he can limit the analysis to predict the response due to mistuning to the estimated range of frequencies.
Condition Monitoring of Ball Bearing Using Vibration Analysis and Feature Ext...IRJET Journal
This document discusses condition monitoring of ball bearings using vibration analysis and feature extraction. It presents an experimental setup to analyze ball bearing vibration under different loads using an FFT analyzer. Frequency spectra are obtained for healthy and defective bearings, showing higher peaks for defective cases. Features like RMS, variance, mean and standard deviation are extracted from the spectra and plotted against load to identify defects in the outer race, inner race and balls of bearings. The goal is to detect bearing faults early through vibration monitoring and feature analysis.
This document summarizes research on using vibration signal analysis to detect wear and identify multiple faults in rolling element bearings operating under harsh conditions. A test rig was used to accelerate wear in bearings filled with contaminated grease. Vibration signals were analyzed in the time and frequency domains. Frequency analysis clearly identified faults developing on bearing raceways over time as peaks emerged at the expected fault frequencies, regardless of noise from random particle contamination. Post-test inspections verified the vibration analysis results had correctly identified the fault sources.
IRJET- Modelling and Condition Monitoring of 3훟 Induction Motor using Fuzzy L...IRJET Journal
This document presents a MATLAB model and simulation of a 3-phase induction motor for condition monitoring using fuzzy logic. The model monitors for common faults like stator winding issues, voltage imbalances, and phase faults. Fuzzy logic membership functions and rules are used to assess the motor's health based on stator current values. Simulations show the motor operating normally and with introduced faults like turn-to-turn shorts and broken windings. In fault cases, the stator current becomes unbalanced and the fuzzy logic output indicates the motor health deteriorating from good to damaged or seriously damaged states.
Theoretical and experimental studies on vibrations produced by defects in dou...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
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.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
5th LF Energy Power Grid Model Meet-up SlidesDanBrown980551
5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.
This presentation provides valuable insights into effective cost-saving techniques on AWS. Learn how to optimize your AWS resources by rightsizing, increasing elasticity, picking the right storage class, and choosing the best pricing model. Additionally, discover essential governance mechanisms to ensure continuous cost efficiency. Whether you are new to AWS or an experienced user, this presentation provides clear and practical tips to help you reduce your cloud costs and get the most out of your budget.
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
Generating privacy-protected synthetic data using Secludy and MilvusZilliz
During this demo, the founders of Secludy will demonstrate how their system utilizes Milvus to store and manipulate embeddings for generating privacy-protected synthetic data. Their approach not only maintains the confidentiality of the original data but also enhances the utility and scalability of LLMs under privacy constraints. Attendees, including machine learning engineers, data scientists, and data managers, will witness first-hand how Secludy's integration with Milvus empowers organizations to harness the power of LLMs securely and efficiently.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
Dive into the realm of operating systems (OS) with Pravash Chandra Das, a seasoned Digital Forensic Analyst, as your guide. 🚀 This comprehensive presentation illuminates the core concepts, types, and evolution of OS, essential for understanding modern computing landscapes.
Beginning with the foundational definition, Das clarifies the pivotal role of OS as system software orchestrating hardware resources, software applications, and user interactions. Through succinct descriptions, he delineates the diverse types of OS, from single-user, single-task environments like early MS-DOS iterations, to multi-user, multi-tasking systems exemplified by modern Linux distributions.
Crucial components like the kernel and shell are dissected, highlighting their indispensable functions in resource management and user interface interaction. Das elucidates how the kernel acts as the central nervous system, orchestrating process scheduling, memory allocation, and device management. Meanwhile, the shell serves as the gateway for user commands, bridging the gap between human input and machine execution. 💻
The narrative then shifts to a captivating exploration of prominent desktop OSs, Windows, macOS, and Linux. Windows, with its globally ubiquitous presence and user-friendly interface, emerges as a cornerstone in personal computing history. macOS, lauded for its sleek design and seamless integration with Apple's ecosystem, stands as a beacon of stability and creativity. Linux, an open-source marvel, offers unparalleled flexibility and security, revolutionizing the computing landscape. 🖥️
Moving to the realm of mobile devices, Das unravels the dominance of Android and iOS. Android's open-source ethos fosters a vibrant ecosystem of customization and innovation, while iOS boasts a seamless user experience and robust security infrastructure. Meanwhile, discontinued platforms like Symbian and Palm OS evoke nostalgia for their pioneering roles in the smartphone revolution.
The journey concludes with a reflection on the ever-evolving landscape of OS, underscored by the emergence of real-time operating systems (RTOS) and the persistent quest for innovation and efficiency. As technology continues to shape our world, understanding the foundations and evolution of operating systems remains paramount. Join Pravash Chandra Das on this illuminating journey through the heart of computing. 🌟
Nunit vs XUnit vs MSTest Differences Between These Unit Testing Frameworks.pdfflufftailshop
When it comes to unit testing in the .NET ecosystem, developers have a wide range of options available. Among the most popular choices are NUnit, XUnit, and MSTest. These unit testing frameworks provide essential tools and features to help ensure the quality and reliability of code. However, understanding the differences between these frameworks is crucial for selecting the most suitable one for your projects.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-und-domino-lizenzkostenreduzierung-in-der-welt-von-dlau/
DLAU und die Lizenzen nach dem CCB- und CCX-Modell sind für viele in der HCL-Community seit letztem Jahr ein heißes Thema. Als Notes- oder Domino-Kunde haben Sie vielleicht mit unerwartet hohen Benutzerzahlen und Lizenzgebühren zu kämpfen. Sie fragen sich vielleicht, wie diese neue Art der Lizenzierung funktioniert und welchen Nutzen sie Ihnen bringt. Vor allem wollen Sie sicherlich Ihr Budget einhalten und Kosten sparen, wo immer möglich. Das verstehen wir und wir möchten Ihnen dabei helfen!
Wir erklären Ihnen, wie Sie häufige Konfigurationsprobleme lösen können, die dazu führen können, dass mehr Benutzer gezählt werden als nötig, und wie Sie überflüssige oder ungenutzte Konten identifizieren und entfernen können, um Geld zu sparen. Es gibt auch einige Ansätze, die zu unnötigen Ausgaben führen können, z. B. wenn ein Personendokument anstelle eines Mail-Ins für geteilte Mailboxen verwendet wird. Wir zeigen Ihnen solche Fälle und deren Lösungen. Und natürlich erklären wir Ihnen das neue Lizenzmodell.
Nehmen Sie an diesem Webinar teil, bei dem HCL-Ambassador Marc Thomas und Gastredner Franz Walder Ihnen diese neue Welt näherbringen. Es vermittelt Ihnen die Tools und das Know-how, um den Überblick zu bewahren. Sie werden in der Lage sein, Ihre Kosten durch eine optimierte Domino-Konfiguration zu reduzieren und auch in Zukunft gering zu halten.
Diese Themen werden behandelt
- Reduzierung der Lizenzkosten durch Auffinden und Beheben von Fehlkonfigurationen und überflüssigen Konten
- Wie funktionieren CCB- und CCX-Lizenzen wirklich?
- Verstehen des DLAU-Tools und wie man es am besten nutzt
- Tipps für häufige Problembereiche, wie z. B. Team-Postfächer, Funktions-/Testbenutzer usw.
- Praxisbeispiele und Best Practices zum sofortigen Umsetzen
HCL Notes und Domino Lizenzkostenreduzierung in der Welt von DLAU
C010321630
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 3 Ver. II (May – Jun. 2015), PP 16-30
www.iosrjournals.org
DOI: 10.9790/1676-10321630 www.iosrjournals.org 16 | Page
Modeling and effect of the anomaly of a ball rolling on the
stability of the induction machine operating
Néjib Khalfaoui 1
, Salhi Mohamed Salah 2
, Hamid Amiri 3
1
(LR SITI, ENIT/ ISET Of JENDOUBA, Tunisia)
2
(LR SITI, ENIT / SAAT MATEUR, Tunisia)
3
( Director LR SITI Lab, ENIT /ENIT, Tunisia)
Abstract: This paper deals with statistics related to the distribution of causes of anomalies affecting the
induction machines and in particular ball rolling, besides presenting the kinematic anomalies characteristic
frequencies of the rolling elements. It also presents a mathematical modeling of the anomaly (indentation) on
the outer ring and inner ring of the ball rolling. In this paper, we do not only do a spectral analysis of the
transmitted signal, but also we study the effects of the anomaly on the electrical quantities (stator currents) and
mechanical quantities (load torque) as well as its spread between the elements of the machine and the structure
of the resonance phenomenon that appears around specific frequencies, particularly the effect of the anomaly
on the stability of the operating of the machine. Also a simulation performed by matlab with spectral analysis
and an experimental monitoring by vibration analysis in the laboratory of NDC (Non Destructive Control) will
be the object of a more synthetic analysis.
Keywords: Anomaly modeling, Induction machine, Rolling anomaly, Spectral analysis, Stability of operating.
I. Introduction
In many industrial areas, the monitoring and the diagnosis of the systems play an important role and
allow to know the types of the origins of defects that can affect the systems. Indeed, the electrical drive systems
based on induction machine are widely used in industrial applications thanks to their low cost, their performance
and robustness. In fact, this induction machine is omnipresent in many applications, particularly in high-tech
sectors such as aerospace, nuclear, chemical industries, in transport (metro, trains, propulsion of vehicles and
ships, elevators ), in industry (machine tools, winches), in appliances. It was originally used only in motor but,
again thanks to the development of power electronics, it is increasingly often used as a generator, in the case of
wind turbines for example. Operating costs, mainly related to maintenance, have been increasing [1]. However,
degraded operating modes can occur during the life of the machine. One of the main reasons for these failures
remains ball rolling anomalies. To improve the operating safety of machines, monitoring systems can be
implemented in order to ensure a preventive and systematic maintenance [2] [3]. In this regard, several studies
have been conducted on the reliability of electrical machines made by different industry groups. The main study,
conducted by the company "General Electric", was published in EPRI (Electric Power Research Institute) in
1982; It covers about 5000 engines, of which approximately 97% were induction machines. This study shows
that the ball rolling anomalies account for about 50% of breakdowns of the induction machine (Fig.1).
Many published researches [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], deal with
mechanical anomalies of electrical drive systems based on induction machine, mainly ball rolling defects, but do
not have their mathematical modeling either on the outer or inner ring to subsequently analyze their effects on
electrical and mechanical quantities of the machine and this is where the very objective of this paper which aims
at developing the efficiency of this modeling and the effects of anomalies on the machine. Thus, the creation of
vibration measurements to detect mechanical anomalies rolling type requires the use of vibration sensors often
piezoelectric type conditioners and data acquisition channels. In addition, the spatial positioning of the sensors
must be studied according to the mechanical member to be monitored. As part of the electrical workouts based
induction machine, many researches have been conducted to replace the detection of mechanical anomalies
based on the measurement of vibration magnitudes, by detection based on the measurement of electrical
quantities, such as stator currents of the machine [4]. Furthermore, the stator currents of the induction machine
are often already measured for the control and protection devices.
II. Heading s Statistical study of the induction machine anomalies
Anomalies can be of various origins: electrical, mechanical, thermal, environmental or even magnetic. Their
causes are multiple and can be classified into three groups [3] [4]:
1) Failure generators or anomaly initiators: engine overheating, electrical fault (short circuit), power boost,
electrical insulation problem, wear of mechanical parts (ball rolling), fixations breaking, etc.
2. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 17 | Page
2) Faults amplifiers: frequent overloading, mechanical vibrations, wet environment, continuous heating, poor
lubrication, aging, etc.
3) Manufacturing defects and human errors: manufacturing defects, defective parts, inadequate protections,
bad sizing of the machine, etc [1].
The distribution of defects in the different parts of the engine is shown in Fig.1:
Fig.1: Distribution of anomaly causes in induction machines
The mechanical constraints are high, which explains the high rate of failure entailed by rolling [2]. These
require an increased mechanical maintenance.
III. Mechanical Defects
1. Rolling anomalies
The ball rolling act as an electromechanical interface between the stator and the rotor. In addition, they
represent the holding element of the machine axis, allowing to ensure a proper rotation of the rotor. Most faults
occur in rolling of induction motors as well as the reasons of their aging. This kind of fault is most common in
medium and high power machines. It is usually related to rolling wear and specifically beads degradation, or
tread. Their possible causes are [1][5][6]:
• Wear due to aging,
• High operating temperature,
• Loss of lubrication,
• Contaminated oil
• Mounting defaults
• Tree currents (Shaft Current)
The direct consequences of this failure on the rolling are:
• Holes in the inner and outer raceway grooves.
• The ripple of their tread.
• Corrosion due to water.
• Lubrication fault problem due to the temperature.
• Separation, surface erosion caused by overload.
For the system, this type of defect results in oscillations of the load torque, additional losses and a clearance
between the inner ring and the outer ring of the rolling causing vibrations coming from displacements of the
rotor around the longitudinal machine axis. In the worst case, the presence of a defective rolling can lead to
engine lock
3. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 18 | Page
2. Modeling of rolling anomalies
Consider a rolling in a fixed reference (Oy0z0) [1] [6] [7].
d: ball diameter; Ω: angular velocity
Re: outer radius; Ri: inner radius
Fig.2: Repositories related to a rolling element
2.1. kinematic frequencies:
Defects, cracks, flaking etc..... may exist on the inner rings, outer, on the balls; they generate shock, so the
periodic vibrations when the rotational speeds are constant.
The fundamental frequencies of these vibrations are related to the so-called basic kinematic frequencies:
fc: the cage rotation frequency compared to a fixed reference.
2
c
cf
(1)
fb: rotational frequency of an element with respect to an axis passing through its center:
2
b
bf
(2)
The speeds of relative displacements null at C1 and C2 contact points. Using the frequencies fi of rotation of the
inner ring, fe of the outer ring and the contact angle α, the cage frequency is expressed as:
eic f
Dm
d
f
Dm
d
f
cos
1
2
1cos
1
2
1 (3)
By introducing the frequency and angle α contact, the ball frequency fb is expressed as :
1 cos cos
1 1
2
b e i
Dm d d
f f f
d Dm Dm
(4)
Forms 3 and 4 define the basic kinematic frequencies (cage and ball) from the rotation frequencies of the fi
inner and fe outer rings.
At frequencies fc and fb base associated defects:
-Frequency of rotation of the cage, cage defects:
1 cos 1 cos
1 1
2 2
cagedefects c i e
d d
f f f f
Dm Dm
(5)
- Rotation frequency of a rolling element; Z number of rolling elements:
2
2
cos1
2
1
Dm
d
ff
d
Dm
ff iebelement
(6)
-Frequency due to a defect on the inner ring:
cos1
2
f intb,
Dm
d
ff
Z
f eiringinner
(7)
-Frequency due to a defect on the outer ring:
4. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 19 | Page
cos1
2
f extb,
Dm
d
ff
Z
f ieringouter
(8)
In keeping with calculating arrangements, research works and industrial experts have the following expressions
(9)
(10)
(11)
(12)
With:
fr is the rotor rotation frequency
fb is the rotational frequency of the ball
fc is the cage rotation frequency
fb int the rotational frequency of the inner ring
fb ext the rotational frequency of the outer ring
Z is the number of balls
d is the ball diameter
Dm is the average diameter of the rolling
α is the contact angle.
2.2. Modeling anomaly on the outer ring:
Suppose chipping (indentation) of small size; the passage of a ball on this peeling causes a force in a radial
plane perpendicular to the rotation line with a contact angle α Fig.3 [1][7][12]:
Fig.3: Anomaly on the fixed outer ring
The set of rolling elements causes a series of pulses described in a fixed reference frame (Oxoyo) by a line series;
the pulse frequency is equal to fbext:
1SHA
k
1/fbext
bextf
k
(13)
With SHA : Dirac distribution
These assumptions allow relatively simple mathematical developments to.
A rotating force to the speed (2πfr) of the rotor due to an imbalance, an arrow, to a defect of coaxiality. The
turning force causes a variation in the force between the rolling element and the fault, this force models pulse
amplitude of the series.
The radial force, applied in the stead of the anomaly, is written:
1/( ) (1 cos 2 ).SHA ( )bextr ff t A f t (14)
5. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 20 | Page
with 𝛄 is the rate modulation.
The signal h (t) output from the sensor disposed on the structure of Fig.3 in a radially pulse applied to the right
defect the pulse comb signal is:
S( ) h(t)*f(t) ( ) ( ). ( )t S v H v F v (15)
ν frequency : -∞ < ν <∞
H(ν) : transfer function of sensor structure
( ) ( ) ( ) ( ) * . ( )
2
r r bext fbextF v A v v f v f f SHA v
(16)
fbext
m
SHA ( ) bextv v mf
(17)
With 𝛅 : Dirac distribution
( ) ( )
2( ) . . ( ).
( )
2
fbext fbext bext r
bext
fbext bext r
SHA v SHA v kf f
S v A f H v
SHA v mf f
(18)
The SHAfbext(ν) comb repeats the frequency fbext the Dirac distribution δ (ν) for ν = 0 (convolution). The comb
)( rbextfbext fkfvSHA result of the convolution by )( rfv by SHAfbext(ν) , and
for )( rbextfbext fmfvSHA .
Fig.4: Radial force applied to the right defect.
Fig.5: Spectrum S(ν)
In fact, the spectrum S (ν) contains components whose frequencies are defined by fig.5 .We note that
the impulsive of excitement introduced nfbext components to higher frequencies ; nfbext ; nfbext ± fr, when the
pulses are not Dirac distributed pulses, the components of the pulses become negligible as n increases. nfbext ± fr;
in deed, the faults are represented by periodic pulses of finite length, which does not substantially alter the
components nfbext ± fr .
6. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 21 | Page
2.3. Modeling anomaly on the rotating inner ring .
If we consider the indentation to small size, the passage of a rolling element on this indentation causes a
force in a radial plan perpendicular to the rotation line [1] [3] [7]. This force is in a repository ( oxizi ) in rotation
speed Ω ; its frequency is equal to f bint ( Fig. 6).
Fig.6 : Anomaly on the inner ring
The anomaly in rotation speed Ω = 2πfr rotor encounters a zone between ϑ1 and ϑ2 in which the radial load is not
zero (Fig.7).
Fig.7 : Radial load between ϑ1 and ϑ2
The anomaly due to the indentation in the rotating reference imposes a radial force f (t) represented by a series of
pulses (Fig.8), the ratio τd/Td is independent of Ω . This force meets the radial load q (t) defined in Fig. 9.
Fig.8 : Form of the radial force
Fig.9 : Form of the radial load
7. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 22 | Page
In the fixed reference ( ox0z0 ) the radial force fradiale (t) is defined by the following expression:
(19)
With SHA : Dirac distribution
The application management point of the radial force on the fixed structure varies over time in the speed
Ω = 2πfr This can result in a transfer function whose input varies with the speed of rotation and thus modulates
average transfer function associated to an impulse response ho( t).
(20)
The sensor output signal may be written:
(21)
With:
(22)
And
(23)
Then :
(24)
-The First term in equation:
(25)
This term is independent of the frequency; within the meaning of frequencies it does not alter the spectrum
(kfb int ± qfr ) resulting from the second factor . To avoid overlapping, it is necessary that the spectral width of Q
(v) is lower to fb int .
- The second term of the equation :
the term Q (v). SHAfr(v ) defines a discretization frequency fr of the Fourier Transform of the radial load q
(t).
the term [Q (v). SHA fr ( v) ] * SHA fb int (v ) defines a periodization at frequency fb int from a Q ( v)
.SHA fr ( v) discrete ( figure5);This spectrum contains components at frequencies: kfb int ± qfr :k, q = 1, 2,3 ,
...... .
Fig.10 : Spectrum components of the anomaly
IV. Effect of anomaly '' indentation '' of the inner ring on size electrical and mechanical .
Anomaly rolling the induction machine causes failures depending on how the torque is exerted mechanical load
, it can be destructive to the mechanical parts[6], [8], [11], . Poor working conditions can lead to faulty
mechanical loads causing :
- Torque jerk ,
- On the couples ,
8. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 23 | Page
- A mechanical balance load and torque oscillations ,
- Unbalance phenomena
- Misalignment of rotating shafts
These failures can be classified into two main families :
• the first failure of family succession creating a mechanical eccentricity.
• the second concerns the load torque becomes disrupted.
That during this anomaly will be transferred to the rotor current via the gap permeance and the mechanical
position of the rotor , on the other hand the rotor flux will transmit this discrepancy to the stator current .
Fig.11: Transfer of anomaly in electrical and mechanical quantities
V. Effects of anomaly ‘’indentation’’ in the inner ring on the load torque
During the running rotation having an anomaly indentation on the inner ring , there are shocks causing
vibrations but also the torque jolts that are repeated periodically in time by inducing oscillations of load torque
(Fig. 6) which are measured by a torque meter[4]. Fig. 7 shows a reduced frequency range of the load torque
spectrum comparing the harmonic content for a healthy machine and a machine with a rolling with localized
anomaly on the inner ring[13], [18]. The rotation speed is nominal, is close to 25Hz .
The expression of the load torque (26) may be represented by a DC component C0 amplitude equal to
the electromagnetic torque Cem of the machine and by a series of n harmonic Cn amplitude and pulsation ωn for
anomaly rolling [8] [11] [19].
(26)
The load torque is also expressed in the frequency domain by the following expression :
(27)
With: frequency of oscillation
In this approach, the viscous friction bearings will be neglected, only the inertia of the rotor being
considered . The difference between the electromagnetic torque and the load torque is applied to the inertial
mechanical system that constitutes the rotor of the machine. Thus, the equation of the mechanical model of the
machine is given by the following expression:
9. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 24 | Page
(28)
With: Jr is the inertia of the rotor
Ω(t) angular speed of the rotor
1. Simulation results:
The Fig.12 shows the evolution of load torque versus time and the spectral representation is given in Fig.13,
in the presence of an anomaly on the rolling inner ring.
Fig.12: Instant torque of evolution
Fig.13 : DSP oscillating torque
1.1. Interpretation:
It may be noted in Figure 13, on the pair of spectra in the presence of an abnormality in the rolling, the
occurrence of harmonic lines at frequencies characteristics of anomalies inner ring. However, note that all
possible combinations of characteristic frequencies do not exist. Therefore, the spectral content of the load
torque on working anomalies can not be predicted completely and theoretically.
VI. Effects of oscillation of the torque on the stator currents
The expression of the angular position (29) of the rotor Θ (t) of the induction machine also comprises
oscillations to the same frequencies fn .
(29)
With H(jωn) : mechanical transfer function of the machine is assumed to be known
10. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 25 | Page
Mechanical position to calculate the magnetomotive force (MMF ) rotor which is phase-modulated [3],
[12], . Furthermore, the stator MMF is purely sinusoidal. Multiplying these MMF by the airgap permeance
considered constant at the angular position and time, leads to the expression of the magnetic field , the integral
of this field on the gap surface leads to the magnetic flux and thus the electromotive force (EMF ) across one
phase temporal tap . Given a linear relationship between the EMF phase current is obtained an expression of the
current Is with the amplitude of the stator current , the amplitude Ir of the rotor current , the fundamental angular
frequency ωs of the stator currents and p the number of pairs of poles of the machine
(30)
With
The first term of (30) is related to the contribution of the stator MMF and the second term, phase-
modulated , is related to the contribution of MMF rotor . By considering small amplitude phase modulation is
obtained a simplified expression of the Fourier transform module ( FT ) of the current (31 ) as a function of the
frequency f with and .
FT (31)
The appearance of working anomalies can be identified by analyzing the energy variations in frequency
components fs ± fn in the current spectrum ( fig.20 ) . The βn parameter is obtained under restrictive conditions
as does consider the electromagnetic torque of the constant machine.
VII. Experimental Results
1. Anomaly on the outer ring
The Induction machine on which the experimental tests were carried out presents an anomaly "indentation" of
small dimension on the outer ring of the rolling SKF6208 reference.
Fig.14: Speed of force movement
Fig.15: Spectre of vibration amplitude
For simultaneous representation of Fig. 16 spectrum load torque in the case of an anomaly and healthy
case showing lines and their frequency characteristics.
The DSP of the torque on the shaft of the machine equipped with a rolling with an anomaly on the
outer ring, for a supply frequency fs = 50 Hz machine (rotational frequency of rotor fr=25Hz). We notice the
appearance of harmonics located but focused around a combination of characteristic frequencies. This
characteristic of harmonic variations torque amplitudes is due to the anomaly of the rolling.
11. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 26 | Page
Fig.16: DSP torque for rolling healthy and contaminated
1.2. Interpretation:
The obtained signals given by fig. 14 and 15 show the vibration of a ball rolling, the outer ring is fixed;
the rotational speed of the inner ring is equal 630 rev / min
fbint = fr → 10,60Hz → 94,13ms .
The spectrum contains lines of: ≈ k 65Hz; k = 1, 2, 3, ...... n; Theoretical kinematic frequency 65,38Hz
differs kinematic measured frequency.
Around the first 3 harmonics, lines at ± 8 Hz are observed. This set of lines expresses a defect on the outer ring
and a theoretical frequency of modulation amplitude 65,38Hz.
2. Anomaly on the inner ring
The following results show the vibrations of the ball rolling due to an anomaly „‟ indentation‟‟ on the
inner ring of a rotating induction machine speed 1480 rev/ min , the zoom mode around 680.2Hz fig.17,
(characterizing the anomaly by the fifth harmonic of the fbin frequency due to an indentation on the inner ring )
shows lateral stripes spaced from the rotational frequency ( 25 Hz ) that reflect an amplitude modulation.
Fig.17 : Zoom mode spectrum of the bearing vibrations of induction machine of an anomaly on the inner ring .
The spectrum of this fig.18 Zoom mode structure of the resonance that appears around 780 Hz can be attributed
to the 31st harmonic resonance of the rotation . 780.2 / 25 = 31.2.
12. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 27 | Page
Fig.18 : Zoom mode spectrum around the bearing of the vibration resonance of the induction machine .
The fig.19 shows a simultaneous representation of the load torque spectrum in the case of anomaly and
healthy case by displaying the lines and their characteristic frequencies.
The DSP of the torque on the shaft of the machine equipped with a rolling with an anomaly on the
inner ring for a supply frequency of fs = 50 Hz machine. We notice the appearance of harmonics located but also
to a harmonic package centered around a combination of characteristic frequencies. This packet is characteristic
harmonic torque variations due to the anomaly of the rolling.
Fig.19: DSP torque for rolling healthy and contaminated
The results of experimental measurements of the amplitude of the torque harmonics at the frequency fbint for
different rotational speeds of the machine in the case of a localized defect on the inner ring and given by the
following table1:
Rotation speed (rev / min) 300 600 900 1480
Amplitude of the harmonic torque
(Nm)
0.0018 0.00215 0.00364 0.00656
Table 1: the amplitude of the harmonic torque based on the speed of the machine
2.1.interpretation:
• the evolution of the amplitudes of the harmonic components to ( 605 + k25 ) Hz, k = 0,1,2,3 , ..., frequency due
to the passage of the balls on the notch .
• The evolution of amplitudes close to 100dB around 780 Hz that represent resonances of the structure.
• In addition, regardless of the type of anomaly or location , experimental studies show that the magnitude of the
torque variations caused by rolling defects increases with the mechanical rotation speed . We can then see that
the amplitude of this harmonic varies generally quadratically with the rotational speed.
13. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 28 | Page
3 . Effects of anomaly on the stator currents
The anomaly of the inner ring induces an oscillation of the torque at the frequency fosc , which affect the stability
of operating of the induction machine , this is shown by the experimental results given in Fig.20.
Fig.20: DSP of stator current
The torque oscillation primarily induce harmonics in stator currents of frequency of the lines in the spectrum
|fs ± fosc| with fosc ≈ 21Hz .
VIII. Experimental bench
The experimental bench is composed of:
A three-phase induction machine, the machine is controlled by an inverter ' OMRON ' , the rotor shaft is
coupled to a DC generator which feeds into a rheostat to control the load.
Characteristic of the induction machine:
Nominal power 4 Kw
Nominal speed 1480tr/min
Moment of inertia J= 0.013kgm2
Number of pair of stove P =2
Rolling type ball SKF 6208, to a mechanical rotational frequency from fr = 25Hz, les frequency outer
ring , inner ring , and ball cage are respectively fbext =89.4Hz, fbint =136Hz,
fc = 9.94Hz et fbille = 58.4Hz.
A light Microlog portable terminal for acquiring and storing from the sensor measurements.
Fig.21: Schematic block diagram of the experimental bench
14. Modeling and effect of the anomaly of a ball rolling on the stability of the induction ….
DOI: 10.9790/1676-10321630 www.iosrjournals.org 29 | Page
Fig.22: Photography machines of experimental bench
IX. Conclusion
The experimental measured kinematic frequencies may differ from theoretical ones, especially when
the degradation of raceways is important. This difference may also result from insufficient or excessive load or
accidental rotation of the fixed ring. Anomalies on the outer ring, the inner ring, the rolling elements, and the
cage cause forces or movements, which generate vibrations measured by a sensor generally disposed on the non-
rotating structure. The analysis of the signals delivered by the sensor provides elements in the temporal and
frequency domains. These elements allow us to generate frequency components which are useful for the
monitoring systems that facilitate diagnosis.
During the operating of the machine, a leakage current can pass through the rolling elements; electric
arcs cause hot spots or mergers by rapid cooling after the metal quenching and craters are formed characterized
by light spots with dark edges. For low currents alteration is less marked identified; it results in the grooves ''
indentation ''. To this effect, the Shocks produced by the passage of the balls on the indentation provoke the
structures to respond through their own frequencies, which are particularly high. Thus, the evolution of the
amplitudes of the received signal around these frequencies represents the resonances of the structure, detecting
rolling anomalies by analysis of electrical current is relevant, but the major problem of current analysis is that
mechanical defects are often embedded in noise or masked by strong electrical contribution, which does not
allow a proper diagnosis from the electric current. To overcome these problems of resonance and noise, some
methods, so-called high frequency resolution (HRF) were applied to help anomaly detection and diagnosis of
the machines. However, the vibration monitoring method is often expensive because of the measurement chain.
Through extensive researches conducted in order to compensate for vibration analysis, an approach based on the
analysis and treatment of stator currents by intelligent modern techniques, has involved neural networks with
genetic algorithm.
References
[1]. N. Khalfaoui, M. S Salhi, H Amiri ‟‟Anomaly Detection in Induction Machines‟‟ 2nd International Conference on Automation,
Control, Engineering and Computer Science; ACECS-2015 Sousse, Tunisia.
[2]. B Trajin, J. Regnier, J. Faucher, Indicator for bearing fault detection in asynchronous motors using stator current spectral analysis,
International Symposium on Industrial Electronics, Juin-Juillet 2008, pp. 570-575.
[3]. F. Immovilli, C. Bianchini, M. Cocconcelli, A. Bellini, R. Rubini, "Bearing Fault Model for Induction Motor With Externally
Induced Vibration," IEEE Trans. ind. Electron., vo1.60, no. S, pp. 340S-341S, Aug. 2013. ,
[4]. B. Trajin, Détection automatique et diagnostic des défauts de roulements dans une machine asynchrone par analyse spectrale des
courants statoriques, Conférence des jeunes chercheurs en génie électrique (JCGE), Décembre 2008, pp. 220-225.
[5]. R. N. Andriamalala, H. Razik, L. Baghli, F. M. Sargos, Eccentricity fault diagnosis of a dual-stator winding induction machine
drive considering the slotting effects, IEEE Transactions on Industrial Electronics, vol. 55, no. 12, D´ecembre 2008, pp. 4238-4251.
[6]. R.BIGRET, J. L. FERON " Diagnostic- Maintenance disponibilité des machines tournantes " COLLECTION TECHNIQUES Ed.
MASSON pp. 293-294-295.
[7]. Y. Gritli, L. Zarri, C. Rossi, F. Filippetti, G.-A. Capolino, and D. Casadei, “Advanced diagnosis of electrical faults in wound rotor
induction machines,” IEEE Trans. Ind. Electron., vol. 60, no. 9, pp. 4012–4024, Sept. 2013.
[8]. Javier A. Rosero, Antonio García , Luis Romeral ,and Jordi Cusidó "Fault Detection in Induction Machines Using Power Spectral
Density in Wavelet Decomposition " IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 55, NO. 2,
FEBRUARY 2008
[9]. A. Bellini, F. Filippetti, C. Tassoni, and G.-A.Capolino, “Advances in diagnostic techniques for induction machines,” IEEE Trans.
Ind. Electron., vol. 55, no. 12, pp. 4109–4126, 2008.
[10]. Blodt, M. Chabert, J. Regnier, J. Faucher, Mechanical load fault detection in Induction motors by stator current time-frequency
analysis, IEEE Transactions on Industry Applications, vol. 42, no. 6, Novembre - Décembre 2006, pp. 1454-1463.
[11]. M. Blodt, P. Granjon, B. Raison, G. Rostaing, Models for bearing damage detection in induction motors using stator current
monitoring, IEEE Transactions on Industrial Electronics, vol. 55, no. 4, Avril 2008, pp. 1813-1822.
[12]. J .R Stack, T.G. Habetler and R.G. Harley, „‟Fault classification and fault signature production for rolling element bearings in
electric machines, IEEE Trans. On Industry Applications, vol. 40 n. 3, pp.735-739, May- Jun. 2004.
[13]. O. V. Thorsen, M. Dalva, "A survey of fault on induction motors in offshore oil industry, petrochemical industry, gas terminals, and
oil refineries" IEEE Transactions on Industry Applications, Vol.31, no.5, pp.1186-1196, September1995.