Zeszyty czasopisma

Tom 15 (2022): Zeszyt 1 (January 2022)

Tom 14 (2021): Zeszyt 1 (January 2021)

Tom 13 (2020): Zeszyt 1 (January 2020)

Tom 12 (2019): Zeszyt 1 (January 2019)

Tom 11 (2018): Zeszyt 1 (January 2018)

Tom 10 (2017): Zeszyt 5 (January 2017)

Tom 10 (2017): Zeszyt 4 (January 2017)

Tom 10 (2017): Zeszyt 3 (January 2017)

Tom 10 (2017): Zeszyt 2 (January 2017)

Tom 10 (2017): Zeszyt 1 (January 2017)

Tom 9 (2016): Zeszyt 4 (January 2016)

Tom 9 (2016): Zeszyt 3 (January 2016)

Tom 9 (2016): Zeszyt 2 (January 2016)

Tom 9 (2016): Zeszyt 1 (January 2016)

Tom 8 (2015): Zeszyt 4 (January 2015)

Tom 8 (2015): Zeszyt 3 (January 2015)

Tom 8 (2015): Zeszyt 2 (January 2015)

Tom 8 (2015): Zeszyt 1 (January 2015)

Tom 7 (2014): Zeszyt 5 (January 2014)

Tom 7 (2014): Zeszyt 4 (January 2014)

Tom 7 (2022): Zeszyt 3 (January 2022)

Tom 7 (2022): Zeszyt 2 (January 2022)

Tom 7 (2014): Zeszyt 1 (January 2014)

Tom 6 (2013): Zeszyt 5 (January 2013)

Tom 6 (2013): Zeszyt 4 (January 2013)

Tom 6 (2013): Zeszyt 3 (January 2013)

Tom 6 (2013): Zeszyt 2 (January 2013)

Tom 6 (2013): Zeszyt 1 (January 2013)

Tom 5 (2012): Zeszyt 4 (January 2012)

Tom 5 (2012): Zeszyt 3 (January 2012)

Tom 5 (2012): Zeszyt 2 (January 2012)

Tom 5 (2012): Zeszyt 1 (January 2012)

Tom 4 (2011): Zeszyt 4 (January 2011)

Tom 4 (2011): Zeszyt 3 (January 2011)

Tom 4 (2011): Zeszyt 2 (January 2011)

Tom 4 (2011): Zeszyt 1 (January 2011)

Tom 3 (2010): Zeszyt 4 (January 2010)

Tom 3 (2010): Zeszyt 3 (January 2010)

Tom 3 (2010): Zeszyt 2 (January 2010)

Tom 3 (2010): Zeszyt 1 (January 2010)

Tom 2 (2009): Zeszyt 4 (January 2009)

Tom 2 (2009): Zeszyt 3 (January 2009)

Tom 2 (2009): Zeszyt 2 (January 2009)

Tom 2 (2009): Zeszyt 1 (January 2009)

Tom 1 (2008): Zeszyt 4 (January 2008)

Tom 1 (2008): Zeszyt 3 (January 2008)

Tom 1 (2008): Zeszyt 2 (January 2008)

Tom 1 (2008): Zeszyt 1 (January 2008)

Informacje o czasopiśmie
Format
Czasopismo
eISSN
1178-5608
Pierwsze wydanie
01 Jan 2008
Częstotliwość wydawania
1 raz w roku
Języki
Angielski

Wyszukiwanie

Tom 5 (2012): Zeszyt 3 (January 2012)

Informacje o czasopiśmie
Format
Czasopismo
eISSN
1178-5608
Pierwsze wydanie
01 Jan 2008
Częstotliwość wydawania
1 raz w roku
Języki
Angielski

Wyszukiwanie

11 Artykułów
access type Otwarty dostęp

Preparation and Characterization of Zirconia Based Thick Film Resistor as a Ammonia Gas Sensor

Data publikacji: 01 Sep 2012
Zakres stron: 540 - 558

Abstrakt

Abstract

Thick film technique is popular because of low cost, simple for construction and better sensing surface area, hence for resistive gas sensor thick films of pure ZrO2 powder were prepared by Standard screen printing technique. The material was characterized by X-Ray diffraction pattern, surface morphology was observed by SEM, elemental composition were observed by EDAX and optical properties were studied with UV spectroscopy Techniques, electrical properties were studying with different applied voltages and at different working temperature. X-Ray Diffraction studies confirmed that the combinations of tetragonal and monoclinic structure. The energy band gap and the thicknesses of the films were evaluated, the crystalline grain size was determined using Scherrer’s formula. The gas sensing performances of various gases were tested with working temperatures from 100° to 500°c. The sensitivity and selectivity to different gases was tested and the resistive thick films showed highest response to NH3 (100 ppm) at 300°c. It was observed that increase in gas concentration its sensing response goes on increasing but slowly increase being still constant for higher concentration. The sensitivity and selectivity may be further enhanced by doping other element and ZrO2 can be stabilize by mixing other oxides. The quick response and fast recovery time was recorded.

Index terms

  • ZrO thick film
  • Screen printing technique
  • NH sensors
  • high sensitivity
  • fast response and recovery time
access type Otwarty dostęp

Physical and Virtual Intelligent Sensors for Integrated Health Management Systems

Data publikacji: 07 Nov 2017
Zakres stron: 559 - 575

Abstrakt

Abstract

This paper describes the development of intelligent sensors as part of an integrated systems approach. The integrated systems approach treats the sensor as a complete system with its own sensing hardware (the traditional sensor), A/D converter, processing and storage capabilities, software drivers, self-assessment algorithms and communication protocols. The immediate application is the monitoring of rocket test stands, but the technology should be generally applicable to the Integrated Systems Health Monitoring (ISHM) vision. This paper outlines progress made in the development of intelligent sensors by describing the work done to date on Physical Intelligent Sensors (PIS) and Virtual Intelligent Sensors (VIS). The PIS as discussed here consists of a thermocouple used to read temperature in an analog form which is then converted into digital values. A microprocessor collects the sensor readings and runs numerous embedded event detection routines on the digital data. If any event, i.e. spike, drift, noise, is detected, it is reported, stored and sent to a remote system through an Ethernet connection. Hence the output of the PIS is data coupled with a confidence factor in the reliability of the data. The VIS discussed here is a virtual implantation of the PIS in C++. The VIS is designed to mirror the operations of the PIS; however, the VIS works on a computer at which digital data is provided as the input and is thus portable to any sensor system. This work lays the foundation for the next generation of smart devices that have embedded intelligence for distributed decision making capabilities.

Idex Terms

  • Intelligent sensors
  • ISHM
  • anomaly detection
  • data correction
access type Otwarty dostęp

Fpga Modelling and Real-Time Embedded Control Design Via Labview Software: Application for Swinging-Up a Pendulum

Data publikacji: 01 Sep 2012
Zakres stron: 576 - 591

Abstrakt

Abstract

In this paper, Real-Time embedded control is designed via LabVIEW software for swinging-up a pendulum from its pending position to its upright position. Since the pendulum system has a typical nonlinear instable model, the control problem is achieved using the Astrom-Furuta energy control strategy. To overcome the complexities for the design and the real-Time implementation of the controller of the nonlinear system, FPGA and Real-Time Modules of LabVIEW software are used. A validation test is finally achieved using Proteus software via its Virtual Simulation Models (VSM). Simulation results show the capabilities of LabVIEW FPGA and Real-Time modules to customize control applications with flexible time control without VHDL coding or board design.

Index terms

  • Field programmable gate arrays
  • Programmable control
  • Software design
  • Inverted pendulum
access type Otwarty dostęp

Preparation of MoO3 Thin Films by Spray Pyrolysis and its Gas Sensing Performance

Data publikacji: 01 Sep 2012
Zakres stron: 592 - 605

Abstrakt

Abstract

MoO3 thin films have been prepared by a simple spray pyrolysis technique at substrate temperature 250°c. The structure and morphology of thin films are characterized by X-ray powder diffraction (XRD), scanning electron microscopy and UV-vis spectroscopy. The gas sensing properties of MoO3 thin film is studied at gas concentration 400 ppm and working temperature of 100–400 °c. It was found that the sensitivity depended on the working temperatures and also H2S gas concentration. The results show that the MoO3 thin film can be used to fabricate high performance H2S gas sensors.

Index terms

  • MoO thin film
  • spray pyrolysis
  • sensor
access type Otwarty dostęp

Effect of Ceo2 Doping on the Structure, Electrical Conductivity and Ethanol Gas Sensing Properties of Nanocrystalline Zno Sensors

Data publikacji: 01 Sep 2012
Zakres stron: 606 - 623

Abstrakt

Abstract

Nanocrystalline sensors having the general formula ZnO + x wt% CeO2, where x = 0, 2, 4 and 6 were prepared by chemical precipitation method and sintered at 400, 600 and 800 °c for 2h in static air atmosphere. The crystal structure and the morphology of the prepared samples were investigated and characterized by using XRD, IR, SEM and TEM techniques. The investigation revealed that the average crystallites size increases with increasing the sintering temperature. The electrical conductivity is found to increase with CeO2 additions and sintering temperature. Gas sensing properties of the prepared samples were also investigated. The effect of CeO2 content and sintering temperature on the structure, electrical conductivity and ethanol gas sensing properties of the prepared samples are discussed.

Index terms

  • ZnO nanoparticles
  • Ce-doping
  • ethanol gas sensor
access type Otwarty dostęp

Modeling and Controller Design of Pneumatic Actuator System with Control Valve

Data publikacji: 01 Sep 2012
Zakres stron: 624 - 644

Abstrakt

Abstract

Pneumatic actuators offer several advantages over electromechanical and hydraulic actuators for positioning applications. Nonetheless, pneumatic actuators are subject to high friction forces, dead band and dead time, which make fast and accurate position control difficult to achieve. This research paper presents the process of controller identification, design, modeling and control for pneumatic actuator system. System Identification approach is used with the purpose to estimate the mathematical model of pneumatic actuator system and for controller design. Data collection of input and output signal of the system has been performed from experiment procedure. This data is used for estimate the model by selecting Auto-Regressive Exogenous (ARX) model as a model structure. The accepted model is based validation test namely as residual correlation, Akaike Final Prediction Error and best fit percentage. Different control schemes such as PID and LQR (Linear Quadratic Regulator) have been applied for controller design. PID controllers with Ziegler Nichols tuning are enabled to provide good performance in various systems. The effects of Tustin transformation, zero order hold and discrete model are tested in PID controller designed. The methodology for this paper combines off-line model based on analysis with on-line iteration. Different external loads are added in order to investigate the effectiveness to the designed controllers in real time system. The tracking performance of the closed loop system is satisfied which offers considerable robustness even on a slight increase in load. The results obtained in the experiment are successful to prove that the output signals which with the controller are almost the same for both simulation and experimental modes.

Index terms

  • Pneumatic actuator system
  • ARX model
  • System identification
  • PID controller
  • LQR controller
access type Otwarty dostęp

Transient Dynamic Behavior of Two Phase Magneto-Electro-Elastic Sensors Bonded to Elastic Rectangular Plates

Data publikacji: 01 Sep 2012
Zakres stron: 645 - 672

Abstrakt

Abstract

Transient dynamic behavior of Magneto-electro-elastic (MEE) sensors bonded to a mild steel plate using 3D magnetic vector potential approach is presented. The electric field induced by time varying magnetic field is non-conservative and can be described by electric scalar potential and magnetic vector potentials. The aim of the study is to find how different volume fractions of the MEE composite behave in sensor applications at various locations on the plate subjected to different boundary conditions. The 3D plate and the sensor are modeled using eight nodded brick element with sufficient numbers of elements across the thickness direction to capture the bending behavior of the plate correctly. The four boundary conditions chosen are one symmetric boundary condition (CCCC), one free edge (CCFC), two adjacent free edges (CFFC) and two opposite free edges (FCFC). It is seen that the electric response is maximum when volume fraction vf=0.2 for all sensor locations with different boundary conditions. The boundary conditions significantly influence the magnetic response; volume fraction vf=0.4 gives noticeably higher values of magnetic potential in almost all the cases except for CFFC boundary condition with sensor near the edge and FCFC boundary condition with sensor at an off set distance from the edge.

Index terms

  • Magneto-electro-elastic
  • sensor
  • magnetic vector potential
  • transient response
  • finite element
access type Otwarty dostęp

Synthesis of Nanostructured ZrO2 for Gas Sensing Application

Data publikacji: 01 Sep 2012
Zakres stron: 673 - 684

Abstrakt

Abstract

Nanocrystalline ZrO2 (Zirconia) has been synthesized by a conventional precipitation method. The structural, morphological, microstructural, optical and gas-sensing properties of ZrO2 were investigated by using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and static gas sensing unit, respectively. X-ray diffraction pattern and TEM of the synthesized product reveal their nano-crystalline nature with grain size 18 nm and 20 nm, respectively. Gas sensing properties of their thick films, which were fabricated by screen-printing to various gases (O2, NO2, C2H5OH, CO, CO2, NH3, LPG, H2S and H2) were tested in ambient air. The ZrO2 thick films showed a high response and selectivity to H2S gas. The effect of operating temperature, gas concentration on the sensing characteristics of these films towards H2S was discussed..

Index terms

  • zirconia nanopowder
  • conventional precipitation method
  • characterization
  • HS sensor
access type Otwarty dostęp

An Appropriate Procedure for Detection of Journal-Bearing Fault using Power Spectral Density, K-Nearest Neighbor and Support Vector Machine

Data publikacji: 01 Sep 2012
Zakres stron: 685 - 700

Abstrakt

Abstract

Journal-bearings play a significant role in industrial applications and the necessity of condition monitoring with nondestructive tests is increasing. This paper deals a proper fault detection technique based on power spectral density (PSD) of vibration signals in combination with K-Nearest Neighbor and Support Vector Machine (SVM). The frequency domain vibration signals of an internal combustion engine with three journal-bearing conditions were gained, corresponding to, (i) normal, (ii) corrosion and (iii) excessive wear. The features of the PSD values of vibration signals were extracted using statistical and vibration parameters. The extracted features were used as inputs to the KNN and SVM for three-class identification. The roles of PSD technique and the KNN and SVM classifiers were investigated. Results showed that the accuracy rate of fault diagnosis was 100%. Also, the results demonstrated that the combined PSD-SVM model had the potential for fault diagnosis of engine journal-bearing.

Index terms

  • condition monitoring
  • power spectral density
  • k-nearest neighbor
  • support vector machine
  • vibration signal
  • fault diagnosis
access type Otwarty dostęp

Comparative Study of Maximum Power Point Tracking using Linear Kalman Filter & Unscented Kalman Filter for Solar Photovoltaic Array on Field Programmable Gate Array

Data publikacji: 01 Sep 2012
Zakres stron: 701 - 716

Abstrakt

Abstract

The paper proposes comparative study of Field Programmable Gate Array implementation of 2 closely related approaches to track maximum power point of a solar photovoltaic array. The current work uses 2 versions of kalman filter viz. linear kalman filter and unscented kalman filter to track maximum power point. Using either of these approach the maximum power point tracking (MPPT) becomes much faster than using the conventional Perturb & Observe approach specifically in case of sudden weather changes. In this paper comparative analysis of both the algorithms being implemented on FPGA is presented. Experiments have been performed under optimal conditions as well as under cloudy conditions i.e. falling irradiance levels. Using the linear kalman filter the maximum power point of a solar PV array has been tracked with an efficiency of 97.11% while using the unscented kalman filter technique the maximum power point of the same solar PV array is tracked with higher efficiency of 98.3%. However, the maximum power point has been tracked at a much faster rate i.e. 4.5 ms using the linear kalman filter approach as compared to the unscented kalman filter approach which tracks maximum power point at 11 ms which is in turn faster than existing generic Perturb and Observe approach which takes 15ms to track the maximum power point. The system has been implemented on Altera EP2C20F484C7 FPGA board.

Index Terms

  • Maximum Power Point Tracking (MPPT)
  • Kalman Filter
  • Unscented Kalman Filter
  • Perturb and Observe (P&O)
  • Photovoltaic (PV)
  • FPGA
access type Otwarty dostęp

Imperialist Competitive Algorithm-Based Fuzzy Pid Control Methodology for Speed Tracking Enhancement of Stepper Motor

Data publikacji: 01 Sep 2012
Zakres stron: 717 - 741

Abstrakt

Abstract

Precise control of the stepper motor has always been a topic of interest and also a challenging issue among control engineering researchers due to the nonlinear nature of the motor dynamic. Abrupt influences of the uncertainties on the model’s dynamic and control performance, on the other hand, must be taken into account for providing a control methodology including the characteristics of adaption and flexibility. Lack of these items in most of the classic control approaches results in degradation of the control action. The main purpose of this paper is to provide an intelligent approach for improving the functionality of conventional PID controller in the problem of trajectory tracking in permanent magnet stepper motor (PMSM). Combination of a meta-heuristic algorithm called imperialist competitive algorithm (ICA) and fuzzy logic is employed for online tuning of PID controller. This, consequently, establishes an intelligent structure, fuzzy-PID controller (FPID), which is more flexible and accurate both in certain and uncertain situations. Using a systematic approach in designing the optimal fuzzy structure based on the ICA is our contribution here which leads to better performance of PMSM. Comparing the results of simulations, done in Matlab Simulink, between the suggested control strategy and performance of the PID, expresses the remarkable capability of FPID in overcoming the complexity of control of the nonlinear and uncertain systems.

Index terms

  • PMSM
  • trajectory tracking
  • ICA
  • FPID controller
  • perturbation
11 Artykułów
access type Otwarty dostęp

Preparation and Characterization of Zirconia Based Thick Film Resistor as a Ammonia Gas Sensor

Data publikacji: 01 Sep 2012
Zakres stron: 540 - 558

Abstrakt

Abstract

Thick film technique is popular because of low cost, simple for construction and better sensing surface area, hence for resistive gas sensor thick films of pure ZrO2 powder were prepared by Standard screen printing technique. The material was characterized by X-Ray diffraction pattern, surface morphology was observed by SEM, elemental composition were observed by EDAX and optical properties were studied with UV spectroscopy Techniques, electrical properties were studying with different applied voltages and at different working temperature. X-Ray Diffraction studies confirmed that the combinations of tetragonal and monoclinic structure. The energy band gap and the thicknesses of the films were evaluated, the crystalline grain size was determined using Scherrer’s formula. The gas sensing performances of various gases were tested with working temperatures from 100° to 500°c. The sensitivity and selectivity to different gases was tested and the resistive thick films showed highest response to NH3 (100 ppm) at 300°c. It was observed that increase in gas concentration its sensing response goes on increasing but slowly increase being still constant for higher concentration. The sensitivity and selectivity may be further enhanced by doping other element and ZrO2 can be stabilize by mixing other oxides. The quick response and fast recovery time was recorded.

Index terms

  • ZrO thick film
  • Screen printing technique
  • NH sensors
  • high sensitivity
  • fast response and recovery time
access type Otwarty dostęp

Physical and Virtual Intelligent Sensors for Integrated Health Management Systems

Data publikacji: 07 Nov 2017
Zakres stron: 559 - 575

Abstrakt

Abstract

This paper describes the development of intelligent sensors as part of an integrated systems approach. The integrated systems approach treats the sensor as a complete system with its own sensing hardware (the traditional sensor), A/D converter, processing and storage capabilities, software drivers, self-assessment algorithms and communication protocols. The immediate application is the monitoring of rocket test stands, but the technology should be generally applicable to the Integrated Systems Health Monitoring (ISHM) vision. This paper outlines progress made in the development of intelligent sensors by describing the work done to date on Physical Intelligent Sensors (PIS) and Virtual Intelligent Sensors (VIS). The PIS as discussed here consists of a thermocouple used to read temperature in an analog form which is then converted into digital values. A microprocessor collects the sensor readings and runs numerous embedded event detection routines on the digital data. If any event, i.e. spike, drift, noise, is detected, it is reported, stored and sent to a remote system through an Ethernet connection. Hence the output of the PIS is data coupled with a confidence factor in the reliability of the data. The VIS discussed here is a virtual implantation of the PIS in C++. The VIS is designed to mirror the operations of the PIS; however, the VIS works on a computer at which digital data is provided as the input and is thus portable to any sensor system. This work lays the foundation for the next generation of smart devices that have embedded intelligence for distributed decision making capabilities.

Idex Terms

  • Intelligent sensors
  • ISHM
  • anomaly detection
  • data correction
access type Otwarty dostęp

Fpga Modelling and Real-Time Embedded Control Design Via Labview Software: Application for Swinging-Up a Pendulum

Data publikacji: 01 Sep 2012
Zakres stron: 576 - 591

Abstrakt

Abstract

In this paper, Real-Time embedded control is designed via LabVIEW software for swinging-up a pendulum from its pending position to its upright position. Since the pendulum system has a typical nonlinear instable model, the control problem is achieved using the Astrom-Furuta energy control strategy. To overcome the complexities for the design and the real-Time implementation of the controller of the nonlinear system, FPGA and Real-Time Modules of LabVIEW software are used. A validation test is finally achieved using Proteus software via its Virtual Simulation Models (VSM). Simulation results show the capabilities of LabVIEW FPGA and Real-Time modules to customize control applications with flexible time control without VHDL coding or board design.

Index terms

  • Field programmable gate arrays
  • Programmable control
  • Software design
  • Inverted pendulum
access type Otwarty dostęp

Preparation of MoO3 Thin Films by Spray Pyrolysis and its Gas Sensing Performance

Data publikacji: 01 Sep 2012
Zakres stron: 592 - 605

Abstrakt

Abstract

MoO3 thin films have been prepared by a simple spray pyrolysis technique at substrate temperature 250°c. The structure and morphology of thin films are characterized by X-ray powder diffraction (XRD), scanning electron microscopy and UV-vis spectroscopy. The gas sensing properties of MoO3 thin film is studied at gas concentration 400 ppm and working temperature of 100–400 °c. It was found that the sensitivity depended on the working temperatures and also H2S gas concentration. The results show that the MoO3 thin film can be used to fabricate high performance H2S gas sensors.

Index terms

  • MoO thin film
  • spray pyrolysis
  • sensor
access type Otwarty dostęp

Effect of Ceo2 Doping on the Structure, Electrical Conductivity and Ethanol Gas Sensing Properties of Nanocrystalline Zno Sensors

Data publikacji: 01 Sep 2012
Zakres stron: 606 - 623

Abstrakt

Abstract

Nanocrystalline sensors having the general formula ZnO + x wt% CeO2, where x = 0, 2, 4 and 6 were prepared by chemical precipitation method and sintered at 400, 600 and 800 °c for 2h in static air atmosphere. The crystal structure and the morphology of the prepared samples were investigated and characterized by using XRD, IR, SEM and TEM techniques. The investigation revealed that the average crystallites size increases with increasing the sintering temperature. The electrical conductivity is found to increase with CeO2 additions and sintering temperature. Gas sensing properties of the prepared samples were also investigated. The effect of CeO2 content and sintering temperature on the structure, electrical conductivity and ethanol gas sensing properties of the prepared samples are discussed.

Index terms

  • ZnO nanoparticles
  • Ce-doping
  • ethanol gas sensor
access type Otwarty dostęp

Modeling and Controller Design of Pneumatic Actuator System with Control Valve

Data publikacji: 01 Sep 2012
Zakres stron: 624 - 644

Abstrakt

Abstract

Pneumatic actuators offer several advantages over electromechanical and hydraulic actuators for positioning applications. Nonetheless, pneumatic actuators are subject to high friction forces, dead band and dead time, which make fast and accurate position control difficult to achieve. This research paper presents the process of controller identification, design, modeling and control for pneumatic actuator system. System Identification approach is used with the purpose to estimate the mathematical model of pneumatic actuator system and for controller design. Data collection of input and output signal of the system has been performed from experiment procedure. This data is used for estimate the model by selecting Auto-Regressive Exogenous (ARX) model as a model structure. The accepted model is based validation test namely as residual correlation, Akaike Final Prediction Error and best fit percentage. Different control schemes such as PID and LQR (Linear Quadratic Regulator) have been applied for controller design. PID controllers with Ziegler Nichols tuning are enabled to provide good performance in various systems. The effects of Tustin transformation, zero order hold and discrete model are tested in PID controller designed. The methodology for this paper combines off-line model based on analysis with on-line iteration. Different external loads are added in order to investigate the effectiveness to the designed controllers in real time system. The tracking performance of the closed loop system is satisfied which offers considerable robustness even on a slight increase in load. The results obtained in the experiment are successful to prove that the output signals which with the controller are almost the same for both simulation and experimental modes.

Index terms

  • Pneumatic actuator system
  • ARX model
  • System identification
  • PID controller
  • LQR controller
access type Otwarty dostęp

Transient Dynamic Behavior of Two Phase Magneto-Electro-Elastic Sensors Bonded to Elastic Rectangular Plates

Data publikacji: 01 Sep 2012
Zakres stron: 645 - 672

Abstrakt

Abstract

Transient dynamic behavior of Magneto-electro-elastic (MEE) sensors bonded to a mild steel plate using 3D magnetic vector potential approach is presented. The electric field induced by time varying magnetic field is non-conservative and can be described by electric scalar potential and magnetic vector potentials. The aim of the study is to find how different volume fractions of the MEE composite behave in sensor applications at various locations on the plate subjected to different boundary conditions. The 3D plate and the sensor are modeled using eight nodded brick element with sufficient numbers of elements across the thickness direction to capture the bending behavior of the plate correctly. The four boundary conditions chosen are one symmetric boundary condition (CCCC), one free edge (CCFC), two adjacent free edges (CFFC) and two opposite free edges (FCFC). It is seen that the electric response is maximum when volume fraction vf=0.2 for all sensor locations with different boundary conditions. The boundary conditions significantly influence the magnetic response; volume fraction vf=0.4 gives noticeably higher values of magnetic potential in almost all the cases except for CFFC boundary condition with sensor near the edge and FCFC boundary condition with sensor at an off set distance from the edge.

Index terms

  • Magneto-electro-elastic
  • sensor
  • magnetic vector potential
  • transient response
  • finite element
access type Otwarty dostęp

Synthesis of Nanostructured ZrO2 for Gas Sensing Application

Data publikacji: 01 Sep 2012
Zakres stron: 673 - 684

Abstrakt

Abstract

Nanocrystalline ZrO2 (Zirconia) has been synthesized by a conventional precipitation method. The structural, morphological, microstructural, optical and gas-sensing properties of ZrO2 were investigated by using X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectroscopy and static gas sensing unit, respectively. X-ray diffraction pattern and TEM of the synthesized product reveal their nano-crystalline nature with grain size 18 nm and 20 nm, respectively. Gas sensing properties of their thick films, which were fabricated by screen-printing to various gases (O2, NO2, C2H5OH, CO, CO2, NH3, LPG, H2S and H2) were tested in ambient air. The ZrO2 thick films showed a high response and selectivity to H2S gas. The effect of operating temperature, gas concentration on the sensing characteristics of these films towards H2S was discussed..

Index terms

  • zirconia nanopowder
  • conventional precipitation method
  • characterization
  • HS sensor
access type Otwarty dostęp

An Appropriate Procedure for Detection of Journal-Bearing Fault using Power Spectral Density, K-Nearest Neighbor and Support Vector Machine

Data publikacji: 01 Sep 2012
Zakres stron: 685 - 700

Abstrakt

Abstract

Journal-bearings play a significant role in industrial applications and the necessity of condition monitoring with nondestructive tests is increasing. This paper deals a proper fault detection technique based on power spectral density (PSD) of vibration signals in combination with K-Nearest Neighbor and Support Vector Machine (SVM). The frequency domain vibration signals of an internal combustion engine with three journal-bearing conditions were gained, corresponding to, (i) normal, (ii) corrosion and (iii) excessive wear. The features of the PSD values of vibration signals were extracted using statistical and vibration parameters. The extracted features were used as inputs to the KNN and SVM for three-class identification. The roles of PSD technique and the KNN and SVM classifiers were investigated. Results showed that the accuracy rate of fault diagnosis was 100%. Also, the results demonstrated that the combined PSD-SVM model had the potential for fault diagnosis of engine journal-bearing.

Index terms

  • condition monitoring
  • power spectral density
  • k-nearest neighbor
  • support vector machine
  • vibration signal
  • fault diagnosis
access type Otwarty dostęp

Comparative Study of Maximum Power Point Tracking using Linear Kalman Filter & Unscented Kalman Filter for Solar Photovoltaic Array on Field Programmable Gate Array

Data publikacji: 01 Sep 2012
Zakres stron: 701 - 716

Abstrakt

Abstract

The paper proposes comparative study of Field Programmable Gate Array implementation of 2 closely related approaches to track maximum power point of a solar photovoltaic array. The current work uses 2 versions of kalman filter viz. linear kalman filter and unscented kalman filter to track maximum power point. Using either of these approach the maximum power point tracking (MPPT) becomes much faster than using the conventional Perturb & Observe approach specifically in case of sudden weather changes. In this paper comparative analysis of both the algorithms being implemented on FPGA is presented. Experiments have been performed under optimal conditions as well as under cloudy conditions i.e. falling irradiance levels. Using the linear kalman filter the maximum power point of a solar PV array has been tracked with an efficiency of 97.11% while using the unscented kalman filter technique the maximum power point of the same solar PV array is tracked with higher efficiency of 98.3%. However, the maximum power point has been tracked at a much faster rate i.e. 4.5 ms using the linear kalman filter approach as compared to the unscented kalman filter approach which tracks maximum power point at 11 ms which is in turn faster than existing generic Perturb and Observe approach which takes 15ms to track the maximum power point. The system has been implemented on Altera EP2C20F484C7 FPGA board.

Index Terms

  • Maximum Power Point Tracking (MPPT)
  • Kalman Filter
  • Unscented Kalman Filter
  • Perturb and Observe (P&O)
  • Photovoltaic (PV)
  • FPGA
access type Otwarty dostęp

Imperialist Competitive Algorithm-Based Fuzzy Pid Control Methodology for Speed Tracking Enhancement of Stepper Motor

Data publikacji: 01 Sep 2012
Zakres stron: 717 - 741

Abstrakt

Abstract

Precise control of the stepper motor has always been a topic of interest and also a challenging issue among control engineering researchers due to the nonlinear nature of the motor dynamic. Abrupt influences of the uncertainties on the model’s dynamic and control performance, on the other hand, must be taken into account for providing a control methodology including the characteristics of adaption and flexibility. Lack of these items in most of the classic control approaches results in degradation of the control action. The main purpose of this paper is to provide an intelligent approach for improving the functionality of conventional PID controller in the problem of trajectory tracking in permanent magnet stepper motor (PMSM). Combination of a meta-heuristic algorithm called imperialist competitive algorithm (ICA) and fuzzy logic is employed for online tuning of PID controller. This, consequently, establishes an intelligent structure, fuzzy-PID controller (FPID), which is more flexible and accurate both in certain and uncertain situations. Using a systematic approach in designing the optimal fuzzy structure based on the ICA is our contribution here which leads to better performance of PMSM. Comparing the results of simulations, done in Matlab Simulink, between the suggested control strategy and performance of the PID, expresses the remarkable capability of FPID in overcoming the complexity of control of the nonlinear and uncertain systems.

Index terms

  • PMSM
  • trajectory tracking
  • ICA
  • FPID controller
  • perturbation

Zaplanuj zdalną konferencję ze Sciendo