This document presents a comparative study of monotonic and non-monotonic phase linear time-invariant (LTI) systems using an improved analytical PID controller design. It discusses using gain crossover frequency and phase margin specifications to design controllers that ensure minimum phase margin inside the desired bandwidth. For the comparative study, it uses bode stability criterion, Nyquist stability criterion, and unit step response. It presents a case study comparing the design of controllers for a buck converter system, which exhibits a non-monotonic phase response, using both monotonic and non-monotonic design techniques. The results show that treating the non-monotonic system as monotonic leads to an overvalued proportional gain and undervalued derivative gain in the PID controller.
Design and Implementation of Discrete Augmented Ziegler-Nichols PID ControllerIDES Editor
Although designing and tuning a proportionalintegral-
derivative (PID) controller appears to be conceptually
intuitive, but it can be hard in practice, if multiple (and often
conflicting) objectives such as short transient and high
stability are to be achieved. Traditionally Ziegler Nichols is
widely accepted PID tuning method but it’s performance is
not accepted for systems where precise control is required. To
overcome this problem, the online gain updating method
Augmented Ziegler-Nichols PID (AZNPID) was proposed, with
the amelioration of Ziegler-Nichols PID’s (ZNPID’s) tuning
rule. This study is further extension of [1] for making the
scheme more generalized. With the help of fourth order
Runge-Kutta method, differential equations involved in PID
are solved which significantly improves transient performance
of AZNPID compared to ZNPID. The proposed augmented
ZNPID (AZNPID) is tested on various types of linear processes
and shows improved performance over ZNPID. The results of
the proposed scheme is validated by simulation and also
verified experimentally by implementing on Quanser’s real
time servo-based position control system SRV-02.
Load Frequency Control, Integral control, Fuzzy Logic.IJERA Editor
An analysis of digital Phase-modulated signals is performed based on frequency spectrum which consists of a continuous and a number of discrete components at multiples of clock frequencies. The analysis shows that these components depend on the pulse shape function of multi-level digital signals to be phase modulated. In this paper, the effect of duty cycle, rise and fall times of these multi-level digital signals, on the frequency spectrum is studied. It is observed that the duty cycle variation of 10% results 30 dB increase in undesired component and the 10% increase in rise & fall times increase the power of undesired component by 12 dB. The theoretical observations of the effects are applied on the Binary Offset Carrier (BOC) modulated signals as a case study, to discuss their effects in Global Navigation Satellite Systems (GNSS).
Design of Controllers for Continuous Stirred Tank ReactorIAES-IJPEDS
The objective of the project is to design various controllers for temperature control in Continuous Stirred Tank Reactor (CSTR) systems. Initially Zeigler-Nichols, modified Zeigler-Nichols, Tyreus-Luyben, Shen-Yu and IMC based method of tuned Proportional Integral (PI) controller is designed and comparisons are made with Fuzzy Logic Controller. Simulations are carried out and responses are obtained for the above controllers. Maximum peak overshoot, Settling time, Rise time, ISE, IAE are chosen as performance index. From the analysis it is found that the Fuzzy Logic Controller is a promising controller than the conventional controllers.
Performance Based Comparison Between Various Z-N Tuninng PID And Fuzzy Logic ...ijsc
The objective of this paper is to compare the time specification performance between conventional
controller and Fuzzy Logic controller in position control system of a DC motor. The scope of this research
is to apply direct control technique in position control system. Two types of controller namely PID and
fuzzy logic PID controller will be used to control the output response. This paper was written to reflect on
the work done on the implementation of a fuzzy logic PID controller. The fuzzy controller was used to
control the position of a motor which can be considered for a general basis in any project design
containing logic control. Motor parameters were taken from a datasheet with respect to a real motor and a
simulated model was developed using Matlab Simulink Toolbox. The fuzzy control was also designed using
the Fuzzy Control Toolbox provided within Matlab, with each rule consisting of fuzzy sets conditioned to
provide appropriate response times with regards to the limitations of our chosen motor. The Fuzzy
Inference Engine chosen for our control was the Mamdani Minimum Inference engine. The results of the
control provided response times suitable for our application.
Design and Implementation of Discrete Augmented Ziegler-Nichols PID ControllerIDES Editor
Although designing and tuning a proportionalintegral-
derivative (PID) controller appears to be conceptually
intuitive, but it can be hard in practice, if multiple (and often
conflicting) objectives such as short transient and high
stability are to be achieved. Traditionally Ziegler Nichols is
widely accepted PID tuning method but it’s performance is
not accepted for systems where precise control is required. To
overcome this problem, the online gain updating method
Augmented Ziegler-Nichols PID (AZNPID) was proposed, with
the amelioration of Ziegler-Nichols PID’s (ZNPID’s) tuning
rule. This study is further extension of [1] for making the
scheme more generalized. With the help of fourth order
Runge-Kutta method, differential equations involved in PID
are solved which significantly improves transient performance
of AZNPID compared to ZNPID. The proposed augmented
ZNPID (AZNPID) is tested on various types of linear processes
and shows improved performance over ZNPID. The results of
the proposed scheme is validated by simulation and also
verified experimentally by implementing on Quanser’s real
time servo-based position control system SRV-02.
Load Frequency Control, Integral control, Fuzzy Logic.IJERA Editor
An analysis of digital Phase-modulated signals is performed based on frequency spectrum which consists of a continuous and a number of discrete components at multiples of clock frequencies. The analysis shows that these components depend on the pulse shape function of multi-level digital signals to be phase modulated. In this paper, the effect of duty cycle, rise and fall times of these multi-level digital signals, on the frequency spectrum is studied. It is observed that the duty cycle variation of 10% results 30 dB increase in undesired component and the 10% increase in rise & fall times increase the power of undesired component by 12 dB. The theoretical observations of the effects are applied on the Binary Offset Carrier (BOC) modulated signals as a case study, to discuss their effects in Global Navigation Satellite Systems (GNSS).
Design of Controllers for Continuous Stirred Tank ReactorIAES-IJPEDS
The objective of the project is to design various controllers for temperature control in Continuous Stirred Tank Reactor (CSTR) systems. Initially Zeigler-Nichols, modified Zeigler-Nichols, Tyreus-Luyben, Shen-Yu and IMC based method of tuned Proportional Integral (PI) controller is designed and comparisons are made with Fuzzy Logic Controller. Simulations are carried out and responses are obtained for the above controllers. Maximum peak overshoot, Settling time, Rise time, ISE, IAE are chosen as performance index. From the analysis it is found that the Fuzzy Logic Controller is a promising controller than the conventional controllers.
Performance Based Comparison Between Various Z-N Tuninng PID And Fuzzy Logic ...ijsc
The objective of this paper is to compare the time specification performance between conventional
controller and Fuzzy Logic controller in position control system of a DC motor. The scope of this research
is to apply direct control technique in position control system. Two types of controller namely PID and
fuzzy logic PID controller will be used to control the output response. This paper was written to reflect on
the work done on the implementation of a fuzzy logic PID controller. The fuzzy controller was used to
control the position of a motor which can be considered for a general basis in any project design
containing logic control. Motor parameters were taken from a datasheet with respect to a real motor and a
simulated model was developed using Matlab Simulink Toolbox. The fuzzy control was also designed using
the Fuzzy Control Toolbox provided within Matlab, with each rule consisting of fuzzy sets conditioned to
provide appropriate response times with regards to the limitations of our chosen motor. The Fuzzy
Inference Engine chosen for our control was the Mamdani Minimum Inference engine. The results of the
control provided response times suitable for our application.
Analysis and Design of Conventional Controller for Speed Control of DC Motor ...IJERA Editor
The objective of this paper is to control the speed of the motor using conventional controller; compensator is used to improve the steady state error. To evaluate the performance of the controller, time response analysis is carried out. The time response analysis consists of two type of analysis. One is unit step response analysis and other is performance indices analysis. The paper describes the designing of a closed loop model of the dc motor drive for controlling speed. Accuracy and the dynamic responses are better in a closed loop system. The compensator is used to compensate the parameter of the system in such a way to meet the specification, so that it improves the steady state response of the system and get desired response.
FRACTIONAL ORDER PID CONTROLLER TUNING BASED ON IMC IJITCA Journal
In this work, a class of fractional order controller (FOPID) is tuned based on internal model control
(IMC). This tuning rule has been obtained without any approximation of time delay. Moreover to show
usefulness of fractional order controller in comparison with classical integer order controllers, an
industrial PID controller tuned in a similar way, is compared with FOPID and then robust stability of both
controllers is investigated. Robust stability analysis has been done to find maximum delayed time
uncertainty interval which results in a stable closed loop control system. For a typical system, robust
stability has been done to find maximum time constant uncertainty interval of system. Two clarify the
proposed control system design procedure, three examples have been given.
Parallel control structure scheme for load frequency controller design using ...IJECEIAES
This paper presents load frequency controller design for a single area as well as the multi-area thermal power system using direct synthesis approach with parallel control structure (PCS) scheme. The set-point and load frequency controller has been designed for frequency regulation and maintains tie-line power within a pre-specified limit for LFC power system. The proposed controller has been implemented for single-area, two-area, and four-area thermal power system for frequency regulation. The proposed method shows impressive simulation results compared with existed control method. The robustness of the proposed method has been examined with the help maximum sensitivity and parametric variation in the nominal power system.
Design and optimization of pid controller using genetic algorithmeSAT Journals
Abstract Natural evolution is mimicked by Genetic Algorithms (GAs) which is a stochastic global search method used for optimization. . In missile control systems Proportional Integral Derivative (PID) control is widely used, but due to empirically selected parameters Kp, Ki, Kd it is difficult to achieve parameter optimization. Genetic algorithm is a search algorithm that is based on natural selection and genetics principles.GA is a computational algorithm which deals with genetics of the human body. It evolves with the number of iterations. After ever iteration a better result is expected. These results are checked for the error. The fittest roots or solution are considered for the next generation based on the selection criterion. GA randomly generates the initial population of the PID control parameters according to the calculation of selection (Normalized Geometric Selection), crossover (Arithmetic Crossover) and mutation (Uniform Mutation), thus optimizing the control parameters. Mean Square Error (MSE) value is chosen as the performance assessment index. For a missile altitude control Proportional Integral Derivative (PID) controller using genetic algorithm is implemented & compared with the classical method Zeigler-Nichols (Z-N) in the paper. Z-N method is classical method which tunes the parameters of PID. The parameters of PID are difficult to tune. Tuned parameters give the optimum solution. Optimum solution generally converges to a solution having minimum error. Minimum error gives a response of the system in terms of maximum over shoot, Settling time, Rise time & Steady State Error. The designed PID with the Genetic Algorithm has much faster response than the classical method.
Comparison of Stable NLMF and NLMS Algorithms for Adaptive Noise Cancellation...IJERA Editor
The least mean fourth (LMF) algorithm has several stability problems. Its stability depends on the variance and distribution type of the adaptive filter input, the noise variance, and the initialization of filter weights. A global solution to these stability problems was presented recently for a normalized LMF (NLMF) algorithm. The analysis is done in context of adaptive noise cancellation with Gaussian, binary, and uniform desired signals. The analytical model is shown to accurately predict the optimum solutions. Comparisons of the NLMF and NLMS algorithms are then made for various parameter selections. It is then shown under what conditions the NLMF algorithm is superior to NLMS algorithm for adaptive noise cancelling.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Improving Structural Limitations of Pid Controller For Unstable ProcessesIJERA Editor
PID controllers have structural limitations which make it impossible for a good closed-loop performance to be achieved. A step response with high overshoot and oscillations always results. In controlling processes with resonances, integrators and unstable transfer functions, the PI-PD controller provides a satisfactory closed-loop performance. In this paper, a simple approach to extracting parameters of a PI-PD controller from parameters of the conventional PID controller is presented so that a good closed-loop system performance is achieved. Simulated results from this formation are carried out to show the efficacy of the technique proposed.
Controller Design and Load Frequency Control for Single Area Power System wit...IJERA Editor
The performance of power systems gets worsening due to the presence of sudden load changes, uncertainties of
parameters etc. Therefore the design of load frequency control is very important in the modern power systems.
This paper presents LFC control technique to reject the typical disturbance as well as control the large-scale
system problems. Parameter uncertainty and load disturbance approach has been proposed to LFC design on the
purpose of rejection of typical disturbances. This paper presents the model order reduction technique of Transfer
function of the single area power system by using Routh approximation. The Second-order reduced system
model has proposed instead of full order system to effectively improve the performance of the closed loop
system. This entire approach is simulated in MATLAB environment for a single –area power system. In
addition to this the reduced order power system is converted into digital domain for digital implementation of
load frequency controller.
An approach to Measure Transition Density of Binary Sequences for X-filling b...IJECEIAES
Switching activity and Transition density computation is an essential stage for dynamic power estimation and testing time reduction. The study of switching activity, transition densities and weighted switching activities of pseudo random binary sequences generated by Linear Feedback shift registers and Feed Forward shift registers plays a crucial role in design approaches of Built-In Self Test, cryptosystems, secure scan designs and other applications. This paper proposed an approach to find transition densities, which plays an important role in choosing of test pattern generator We have analyze conventional and proposed designs using our approache, This work also describes the testing time of benchmark circuits. The outcome of this paper is presented in the form of algorithm, theorems with proofs and analyses table which strongly support the same. The proposed algorithm reduces switching activity and testing time up to 51.56% and 84.61% respectively.
“Proposed Model for Network Security Issues Using Elliptical Curve Cryptography”IOSR Journals
Abstract: Elliptic Curve Cryptography (ECC) plays an important role in today’s public key based security
systems. . ECC is a faster and more secure method of encryption as compared to other Public Key
Cryptographic algorithms. This paper focuses on the performance advantages of using ECC in the wireless
network. So in this paper its algorithm has been implemented and analyzed for various bit length inputs. The
Private key is known only to sender and receiver and hence data transmission is secure.
Filtering Unwanted Messages from Online Social Networks (OSN) using Rule Base...IOSR Journals
Online Social Networks (OSNs) are today one of the most popular interactive medium to share,
communicate, and distribute a significant amount of human life information. In OSNs, information filtering can
also be used for a different, more responsive, function. This is owing to the fact that in OSNs there is the
possibility of posting or commenting other posts on particular public/private regions, called in general walls.
Information filtering can therefore be used to give users the ability to automatically control the messages
written on their own walls, by filtering out unwanted messages. OSNs provide very little support to prevent
unwanted messages on user walls. For instance, Facebook permits users to state who is allowed to insert
messages in their walls (i.e., friends, defined groups of friends or friends of friends). Though, no content-based
partialities are preserved and therefore it is not possible to prevent undesired communications, for instance
political or offensive ones, no matter of the user who posts them. To propose and experimentally evaluate an
automated system, called Filtered Wall (FW), able to filter unwanted messages from OSN user walls
Analysis and Design of Conventional Controller for Speed Control of DC Motor ...IJERA Editor
The objective of this paper is to control the speed of the motor using conventional controller; compensator is used to improve the steady state error. To evaluate the performance of the controller, time response analysis is carried out. The time response analysis consists of two type of analysis. One is unit step response analysis and other is performance indices analysis. The paper describes the designing of a closed loop model of the dc motor drive for controlling speed. Accuracy and the dynamic responses are better in a closed loop system. The compensator is used to compensate the parameter of the system in such a way to meet the specification, so that it improves the steady state response of the system and get desired response.
FRACTIONAL ORDER PID CONTROLLER TUNING BASED ON IMC IJITCA Journal
In this work, a class of fractional order controller (FOPID) is tuned based on internal model control
(IMC). This tuning rule has been obtained without any approximation of time delay. Moreover to show
usefulness of fractional order controller in comparison with classical integer order controllers, an
industrial PID controller tuned in a similar way, is compared with FOPID and then robust stability of both
controllers is investigated. Robust stability analysis has been done to find maximum delayed time
uncertainty interval which results in a stable closed loop control system. For a typical system, robust
stability has been done to find maximum time constant uncertainty interval of system. Two clarify the
proposed control system design procedure, three examples have been given.
Parallel control structure scheme for load frequency controller design using ...IJECEIAES
This paper presents load frequency controller design for a single area as well as the multi-area thermal power system using direct synthesis approach with parallel control structure (PCS) scheme. The set-point and load frequency controller has been designed for frequency regulation and maintains tie-line power within a pre-specified limit for LFC power system. The proposed controller has been implemented for single-area, two-area, and four-area thermal power system for frequency regulation. The proposed method shows impressive simulation results compared with existed control method. The robustness of the proposed method has been examined with the help maximum sensitivity and parametric variation in the nominal power system.
Design and optimization of pid controller using genetic algorithmeSAT Journals
Abstract Natural evolution is mimicked by Genetic Algorithms (GAs) which is a stochastic global search method used for optimization. . In missile control systems Proportional Integral Derivative (PID) control is widely used, but due to empirically selected parameters Kp, Ki, Kd it is difficult to achieve parameter optimization. Genetic algorithm is a search algorithm that is based on natural selection and genetics principles.GA is a computational algorithm which deals with genetics of the human body. It evolves with the number of iterations. After ever iteration a better result is expected. These results are checked for the error. The fittest roots or solution are considered for the next generation based on the selection criterion. GA randomly generates the initial population of the PID control parameters according to the calculation of selection (Normalized Geometric Selection), crossover (Arithmetic Crossover) and mutation (Uniform Mutation), thus optimizing the control parameters. Mean Square Error (MSE) value is chosen as the performance assessment index. For a missile altitude control Proportional Integral Derivative (PID) controller using genetic algorithm is implemented & compared with the classical method Zeigler-Nichols (Z-N) in the paper. Z-N method is classical method which tunes the parameters of PID. The parameters of PID are difficult to tune. Tuned parameters give the optimum solution. Optimum solution generally converges to a solution having minimum error. Minimum error gives a response of the system in terms of maximum over shoot, Settling time, Rise time & Steady State Error. The designed PID with the Genetic Algorithm has much faster response than the classical method.
Comparison of Stable NLMF and NLMS Algorithms for Adaptive Noise Cancellation...IJERA Editor
The least mean fourth (LMF) algorithm has several stability problems. Its stability depends on the variance and distribution type of the adaptive filter input, the noise variance, and the initialization of filter weights. A global solution to these stability problems was presented recently for a normalized LMF (NLMF) algorithm. The analysis is done in context of adaptive noise cancellation with Gaussian, binary, and uniform desired signals. The analytical model is shown to accurately predict the optimum solutions. Comparisons of the NLMF and NLMS algorithms are then made for various parameter selections. It is then shown under what conditions the NLMF algorithm is superior to NLMS algorithm for adaptive noise cancelling.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Improving Structural Limitations of Pid Controller For Unstable ProcessesIJERA Editor
PID controllers have structural limitations which make it impossible for a good closed-loop performance to be achieved. A step response with high overshoot and oscillations always results. In controlling processes with resonances, integrators and unstable transfer functions, the PI-PD controller provides a satisfactory closed-loop performance. In this paper, a simple approach to extracting parameters of a PI-PD controller from parameters of the conventional PID controller is presented so that a good closed-loop system performance is achieved. Simulated results from this formation are carried out to show the efficacy of the technique proposed.
Controller Design and Load Frequency Control for Single Area Power System wit...IJERA Editor
The performance of power systems gets worsening due to the presence of sudden load changes, uncertainties of
parameters etc. Therefore the design of load frequency control is very important in the modern power systems.
This paper presents LFC control technique to reject the typical disturbance as well as control the large-scale
system problems. Parameter uncertainty and load disturbance approach has been proposed to LFC design on the
purpose of rejection of typical disturbances. This paper presents the model order reduction technique of Transfer
function of the single area power system by using Routh approximation. The Second-order reduced system
model has proposed instead of full order system to effectively improve the performance of the closed loop
system. This entire approach is simulated in MATLAB environment for a single –area power system. In
addition to this the reduced order power system is converted into digital domain for digital implementation of
load frequency controller.
An approach to Measure Transition Density of Binary Sequences for X-filling b...IJECEIAES
Switching activity and Transition density computation is an essential stage for dynamic power estimation and testing time reduction. The study of switching activity, transition densities and weighted switching activities of pseudo random binary sequences generated by Linear Feedback shift registers and Feed Forward shift registers plays a crucial role in design approaches of Built-In Self Test, cryptosystems, secure scan designs and other applications. This paper proposed an approach to find transition densities, which plays an important role in choosing of test pattern generator We have analyze conventional and proposed designs using our approache, This work also describes the testing time of benchmark circuits. The outcome of this paper is presented in the form of algorithm, theorems with proofs and analyses table which strongly support the same. The proposed algorithm reduces switching activity and testing time up to 51.56% and 84.61% respectively.
“Proposed Model for Network Security Issues Using Elliptical Curve Cryptography”IOSR Journals
Abstract: Elliptic Curve Cryptography (ECC) plays an important role in today’s public key based security
systems. . ECC is a faster and more secure method of encryption as compared to other Public Key
Cryptographic algorithms. This paper focuses on the performance advantages of using ECC in the wireless
network. So in this paper its algorithm has been implemented and analyzed for various bit length inputs. The
Private key is known only to sender and receiver and hence data transmission is secure.
Filtering Unwanted Messages from Online Social Networks (OSN) using Rule Base...IOSR Journals
Online Social Networks (OSNs) are today one of the most popular interactive medium to share,
communicate, and distribute a significant amount of human life information. In OSNs, information filtering can
also be used for a different, more responsive, function. This is owing to the fact that in OSNs there is the
possibility of posting or commenting other posts on particular public/private regions, called in general walls.
Information filtering can therefore be used to give users the ability to automatically control the messages
written on their own walls, by filtering out unwanted messages. OSNs provide very little support to prevent
unwanted messages on user walls. For instance, Facebook permits users to state who is allowed to insert
messages in their walls (i.e., friends, defined groups of friends or friends of friends). Though, no content-based
partialities are preserved and therefore it is not possible to prevent undesired communications, for instance
political or offensive ones, no matter of the user who posts them. To propose and experimentally evaluate an
automated system, called Filtered Wall (FW), able to filter unwanted messages from OSN user walls
Perishable Inventory Model Having Weibull Lifetime and Time Dependent DemandIOSR Journals
In this paper we develop and analyse an inventory model for deteriorating items with Weibull rate of decay and time dependent demand. Using the differential equations, the instantaneous state of inventory at time‘t’, the amount of deterioration etc. are derived. With suitable cost considerations the total cost function and profit rate function are also obtained by maximizing the profit rate function, the optimal ordering and pricing policies of the model are derived. The sensitivity of the model with respect to the parameters is discussed through numerical illustration. It is observed that the deteriorating parameters have a tremendous influence on the optimal selling price and ordering quantity.
Mathematical Modelling: A Comparatively Mathematical Study Model Base between...IOSR Journals
In this paper, we have studied on the topic of „Corruption‟. Also, I will try to find or study the effect of corruption on the Development of the country or any country of the world. Therefore, how find the solution of the problem of corruption will be destroyed completely from the society. We have observed that the Development of the country depends upon Corruption. That is, when the Corruption increases, Development decreases automatically of any country of the world. Therefore, I will try to find the formula on the problem of „Relation between the Corruption and Development of any field or any country of the world‟. Also, I have to highlight the concept of „Application of Mathematical modeling in the interesting problem “corruption” in every field of our country or world .Also, Applied Mathematics focuses on the formulation and study of Mathematical Models .Thus the activity of Applied Mathematics is vitally connected with Research in Pure Mathematics. So I will try to study on it and find, what is corruption and quantity of corruption and also find the growth of corruption and how it will decay? Now we convert this areal world problem to mathematics problem and find some formulae on it such as Mathematical Corruption Growth formula, Mathematical Constant corruption level formula and Mathematical decay of corruption formula.
Fluorescence technique involves the optical detection and spectral analysis of light emitted by a substance undergoing a transition from an excited electronic state to a lower electronic state. The aim of this study is to assess the -amino levulinic acid (-ALA) uptake. Based on image processing technique, Matlab was used to analyze the fluorescence images resulted from activation of (-ALA) and follow its uptake along one week. Analyzing the RGB colours pixel profile from obtained results showed different profiles for malignant tissues, normal tissues, treated just after PDT and finally at one week post PDT. The treated tissues fluorescence profile showed changes from closer to malignant tissue profile till been closed to normal one.
Intelligent Fault Identification System for Transmission Lines Using Artifici...IOSR Journals
Transmission and distribution lines are vital links between generating units and consumers. They are
exposed to atmosphere, hence chances of occurrence of fault in transmission line is very high, which has to be
immediately taken care of in order to minimize damage caused by it. This paper focuses on detecting the faults
on electric power transmission lines using artificial neural networks. A feed forward neural network is
employed, which is trained with back propagation algorithm. Analysis on neural networks with varying number
of hidden layers and neurons per hidden layer has been provided to validate the choice of the neural networks
in each step. The developed neural network is capable of detecting single line to ground and double line to
ground for all the three phases. Simulation is done using MATLAB Simulink to demonstrate that artificial
neural network based method are efficient in detecting faults on transmission lines and achieve satisfactory
performances. A 300km, 25kv transmission line is used to validate the proposed fault detection system.
Hardware implementation of neural network is done on TMS320C6713.
The Effects of Industrial Environment, Innovation, and Government Policy on B...IOSR Journals
This research aims to provide information about the effects of industrial environment on business performance, industrial environment on business performance with innovation as moderating variable, innovation on business performance and innovation on business performance with government policy as moderating variable. The population of this research is all small industries especially Tenun Songket Riau in Pekanbaru City, Bengkalis Sub District, and Siak Sub District, as many as 330 business units. Sampling method used is proportional sampling with total sample of 110 business units. Structural Equation Modeling (SEM) is used as data analysis and to be processed with AMOS 16 software. The findings of this study are as follows: (1) the more dynamic industrial environment results better business performance of small industry of Riau Songket Weaving; (2) the more dynamic industrial environment supports innovation capability and impacts better business performance of small industry of Riau Songket Weaving; (3) the higher innovation capability of the business results better business performance of small industry of Riau Songket Weaving, and (4) the higher innovation capability and to be supported by conducive government policy impacts better business performance of small industry of Riau Songket Weaving.
The Effect Service Quality to Customer Satisfaction and Customer Loyalty of A...IOSR Journals
Customer Loyalty is important for cultivated by the company, therefore the aim of this study to prove
how the effect of Service Quality and Customer Satisfaction in enhancing Customer Loyalty. Samples were
service users Railway Transport Argo Bromo Anggrek Jakarta Surabaya by using purposive side. Sample size of
300 respondents. Data analysis using Structural Equation Model (SEM). The results showed that Services
Quality significantly influence to customer satisfaction. Customer Satisfaction significant effect on Customer
Loyalty. Service Quality is not yet significant effect on Customer Loyalty, so that Customer Satisfaction is a
mediator of the relationship Service Quality on Customer Loyalty to PT Argo Bromo Anggrek Train Jakarta-
Surabaya. The implications that Customer Satisfaction is capable of mediating the quality of care in improving
Customer Loyalty.
Implementation of XOR Based Pad Generation Mutual Authentication Protocol for...IOSR Journals
In RF link, without security the messages exchange between the two devices are monitoring by an
eavesdropper. So the exclusive-OR (XOR) based pad generation protocol is used to safely transfer the data to
the other point with necessary security and it maintaining confidentiality. This protocol produce the cover
coding pad to mask the access password before the datas are transmitted. A specially designed pad generation
will be implemented in digital domain to solve the insecurity problem in data communication RF link. This
protocol developed under regulation of ISO 18000 – 6 type C protocol also known as EPC C1G2 RFID
protocol. The linear feed back shift register (LFSR) generate the pseudo random binary sequence (PRBS) and it
is used as data source to the pad generation function. The Xilinx 13.x software is used for synthesize and
modelsim SE6.0 is used for simulating the result. The pad generation algorithm has been implemented in FPGA
Spartan 3 PQ208-4 board to verify the result
PID controller using rapid control prototyping techniquesIJECEIAES
To analyze the performance of the PID controller in a buck type converter implemented in real time. We begin by designing a continuous controller using the analytical method for calculating PIDs. Pulse width modulation is then used and bifurcation diagrams analyzed to reveal some problems of switching and sampling time. The model converter is then implemented with a PID controller in dSPACE. The experimental results provide detailed requirements of sampling frequency and switching speed, and show the performance of the PID controller. Converters are used in power generation solar systems and conmuted power sources for feed telecommunication devices, smart grids, and other applications.
COMPARATIVE ANALYSIS OF CONVENTIONAL PID CONTROLLER AND FUZZY CONTROLLER WIT...IJITCA Journal
All the real systems exhibits non-linear nature,conventional controllers are not always able to provide good and accurate results. Fuzzy Logic Control is used to obtain better response. A model for simulation is designed and all the assumptions are made before the development of the model. An attempt has been made to analyze the efficiency of a fuzzy controller over a conventional PID controller for a three tank level control system using fuzzification & defuzzification methods and their responses are compared. Analysis is done through computer simulation using Matlab/Simulink toolbox. This study shows that the application of Fuzzy Logic Controller (FLC) gives the best response with triangular membership function and centroid defuzzification method.
DESIGN OF FAST TRANSIENT RESPONSE, LOW DROPOUT REGULATOR WITH ENHANCED STEADY...ijcsitcejournal
Design and implementation of control systems for power supplies require the use of efficient techniques that
provide simple and practical solutions in order to fulfill the performance requirements at an acceptable cost.
Application of manual methods of system identification in determining optimal values of controller settings is
quite time-consuming, expensive and, sometimes, may be impossible to practically carry out. This paper
describes an analytical method for the design of a control system for a fast transient response, low dropout
(LDO) linear regulated power supply on the basis of PID compensation. The controller parameters are
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B010411016
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 4 Ver. I (July – Aug. 2015), PP 10-16
www.iosrjournals.org
DOI: 10.9790/1676-10411016 www.iosrjournals.org 10 | Page
Comparative Study of Monotonic and Non- Monotonic Phase LTI
systems using Improved Analytical PID controller
Monica U. Waikar1
, Nishij G. Kulkarni2
, Dr. Ravindrakumar M. Nagarale3
1
(PG student, M.B.E. Society’s college of engineering, Ambajogai, Maharashtra, India)
2,3
(PG Department, M.B.E. Society’s College of engineering, Ambajogai, Maharashtra, India)
Abstract : A comparative study of monotonic and non monotonic phase LTI systems using analytical design of
PID controller, by means of gain cross over frequency and phase margin specifications, is presented in the
paper. The proposed methodology ensures minimum phase margin inside desired bandwidth giving accurate
performance to step response for closed loop system. Concept of phase margin needs to be redefined when
uncontrolled process presents minimum phase inside bandwidth. For comparative study, bode stability
criterion, nyquist stability criterion and unit step response is used.
Keywords: Improved analytical controller , linear system compensation, monotonic and non-monotonic phase
LTI system.
I. Introduction
A system that maintains a prescribed relationship between the output and the reference input by
comparing them and using the difference as a means of control is called a feedback control system. In case of
feedback control system for monotonically decreasing phase inside bandwidth, phase margin can be defined as
distance between open loop phase at gain crossover frequency and stability limit of−180°. After using bode
stability criterion, if phase margin is positive then closed loop system is stable [1]
In case of classical frequency response it can be considered that phase margin can be defined on gain
cross-over frequency. Whereas this assumption is not valid in general practice, because even for a minimum
phase system with a left half-plane zero located near the dominant- poles, its frequency response will present a
non-monotonic phase.
This abrupt technique shows an improved frequency response design technique for monotonic or non-
monotonic phase (inside the bandwidth) dynamical systems based on gain crossover frequency and phase
margin specifications, which is an expansion of the technique shown by Phillips and Harbor [2], by using this
feature comparative study of monotonic and non-monotonic phase LTI system is possible. To achieve this
feature concept of phase margin can be redefined when the system frequency response shows a non-
monotonically decreasing phase inside the bandwidth. The study of phase margin is necessary due to two
reasons such as it can be considered as good robustness indicator and which allows bode stability criterion for
monotonic and non-monotonic minimum phase systems.
The detailed organization is as follows: section 2 presents problem formulation, some remarks about non-
monotonically decreasing phase can be addressed, for that purpose considered the DC-DC buck regulator.
Section 3 explains detailed study of PID controller design. Section 4 is concerned about simulation and results
where comparative study of monotonic and non-monotonic systems is also explained. Section 5 has conclusion.
II. Problem Formulation
Continuous LTI dynamical system is considered which is given by differential equation,
y(t) + a1 y(t)a0y t = b1u(t) + b0 u t (1)
Here LC low pass filter is to be considered which is commonly used in different type of power
electronics. Hence assume synchronous buck regulator having model no. IRU 3038 used as voltage tracking
application such as DC-DC converter and DDR memory [3]. Buck regulator is taken into considerations which
are combination of power stage given by LC low pass filter and pulse width modulation based controller. The
transfer function of buck converter is output(regulated voltage) to input(PWM input voltage) is,
G s =
VIN
VOSC
1+sRC C
LCS
2 +s RC C+
L
R
+1
(2)
Where ,L is the output inductance, C is the output capacitance, R is the load resistance, RC is the output
capacitor intrinsic resistance,VOSC is the PWM oscillator reference voltage and VIN is the power stage input
voltage. Here assume typical application for buck regulator [3], RC=40ohm, gives transfer function,
G s =
4(1+1.2×10−5s)
3×10−9 s2 +3.6×10−5 s+1
(3)
2. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 11 | Page
Where the un-damped frequency is approximately 18 Krad/s and the damping ratio is approximately 0.33.
Using this transfer function for buck regulator we can find out bode plot shown in fig.1. Here a valley in phase
curve close to un-damped frequency is to be seen. From this we can conclude that left half-plane zero due to the
output capacitor intrinsic resistance is not located far enough from the poles. Hence this leads to non monotonic
phase compensation because bandwidth is located after zero frequency. Due to this transfer function is in
minimum phase and use of bode plot is not possible. Hence we have to study the improved technique of design
of PID controller[4].
Fig.2 Bode plot for Buck regulator
III. Design Of PID Controller
he PID controller is the most common form of feedback. It was an essential element of early governors
and it became the standard tool when process control emerged in the 1940s. In control system today, more than
95% of the control loops are of PID type, most loops are actually PI control. PID controllers are today found in
all areas where control is used. The controllers come in many different forms[5]. PID control is an important
ingredient of a distributed control system. The controllers are also embedded in many special-purpose control
systems. For improving PID control there are various methods such as empiric method by Ziegler and Nichols
and analytical compensation based on pole-placement and frequency response method[6] [7] due to this
popularity of PID controller is tremendously increased.
Consider equation for PID controller,
K s = KP 1 +
1
T1s
TDs (5)
Where KP is the proportional gain,KI is the integral action time or reset time, and TD is known as the derivative
action time or rate time [1], [3].
Fig.1 Design of PID control of plant
For designing of PID controller one tuning method is used i.e. Ziegler Nichols tuning method. This
process of selecting the controller parameters to meet given performance specifications is known as controller
tuning. Ziegler and Nichols suggested rules for tuning PID controllers based on experimental step responses or
based on the value of that results in marginal stability when only proportional control action is used. Ziegler–
Nichols rules, are useful when mathematical models of plants are not known. However, the resulting system
may exhibit a large maximum overshoot in the step response, which is unacceptable. In such case we need series
of fine tunings until an acceptable result is obtained. In fact, the Ziegler–Nichols tuning rules give an educated
guess for the parameter values and provide a starting point for fine tuning, rather than giving the final settings in
a single shot.[6]-[7]. It should be noted that worst case frequency is exactly the gain crossover frequency i.e., it
defines a monotonic phase system, then the set of (4) becomes the well-known compensating equations shown
by Phillips and Harbor [2].
3. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 12 | Page
KP =
1
G(jωn ) 1+ ωu TD −
1
ωu TI
(5a)
ωuTD −
1
ωu TI
= tan φ (5b)
φ ≜ −180° + ∅m −< G(jωm ) (5c)
One major drawback of PID controller is that, it has less equations than variables therefore it is very
important to characterize equations having TIand TD values. By rewriting eq (5) in terms of KP and TD gives,
KP =
1
G(jωn ) 1+Ω2 tan φ+
1−Ω−2
ωm TI
2
(6a)
TD =
tan φ
ωm
+
1
ωm
2 TI
(6b)
By using above equations, variations in PI and PD are occurred having a single unique solution each. In
general practice, the PID controller should not be usually used to compensate non-monotonic phase dynamical
systems since these systems, by their own natural behaviour, already present left half-plane zeros in the open-
loop transfer function, yielding a phase-lead effect very similar to the derivative term present in the standard
form in (6). Therefore, the next subsections will present the equations and some comments on the PI and PD
variations.
3.1 PD controller
Assume TI equal to infinity in eq 5(a,b) we obtain,
KP =
1
G(jωn ) 1+Ω2 tan φ2
(7a)
TD =
tan φ
ωm
(7b)
or KD = KPTD =
ωu
−1
G(jωn ) 1+Ω2 cot φ2
(7c)
Now, it should be noted that if monotonicity ratio is larger than KP gain will be smaller and KD gain will be
larger..
3.2 PI controller
Consider TD equal to zero in eq 5(a,b),
KP =
1
G(jωn ) 1+Ω−2 tan φ2
(8a)
TI = −
cot φ
ωm
(8b)
KI =
KP
TI
=
ωu
G(jωn ) 1+Ω2 cot φ2
(8c)
Here, if monotonicity ratio is larger then KP gain will be larger and KI gain will be smaller. In case of non
monotonic phase system as monotonic phase one should lead overvalued KP gain and to an undervalued KD
gain..Due to this reason compensation of non monotonic phase system as monotonic system is avoided in case
of integral action.
IV. Results And Simulation
In this section tools are presented such as fundamental tools and robustness tools which are widely used in
literature.
4.1 Fundamental tools
In fundamental tools consider the factors which are very important for analytical design procedure.
This procedure gives gain crossover frequency and phase margin for stable and minimum phase using transfer
function which can be obtained from bode criterion. Here damping ratio and un-damped frequency is necessary
having transfer function of second order system.
Let us consider negative feedback system into a low-pass behaviour in the open-loop frequency
response, then define four parameters which can be used in frequency response compensation for dynamical LTI
4. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 13 | Page
systems with non monotonic phase inside bandwidth such as worst case frequency ωm, gain cross over phase
margin ∅u, gain crossover frequency ωu, worst case phase margin ∅m .
The characteristic equation is gain cross over frequency and stability limit of −180° is ωu . For bode
stability criterion if ∅u is positive then system is stable, when system response represents lowest phase inside
bandwidth which is smaller than or equal to the gain crossover frequency ωu whereas worst case phase
margin∅m is distance between open loop phase in worst case frequencyωm, and stability limit of −180°. Solve
equation for frequency domain
K(jωu)G(jωu ∠K jωu G jωu = 1∠ − 180° + ∅u (9a)
With ∅m ≤ ∅u (9b)
If the worst case phase margin ∅ 𝑚 is positive then gain crossover phase margin∅ 𝑢 is positive then system
becomes stable, then 𝜔𝑢 is always larger than or equal to𝜔 𝑚 . Apply bode stability criterion for above equation
it gives,
K(jωu =
1
G(jωu )
(10a)
∠K jωm = −180° + ∅m − ∠G jωm (10b)
With ωm ≤ ωu (10c)
Here to check how system is monotonic then we have to define monotonicity ratio is given by,
Ω ≜
ωu
ωm
(11)
Ω is always greater than or equal to 1. This ratio indicates that if values of is larger then system tends to
non monotonic phase. In next section find the parameters which are useful to shape open loop feedback system
into low pass behaviour inside bandwidth and step response for closed loop system in case of gain cross over
frequency and phase margin.
4.2 Robustness tools
The analytical design procedure includes various characteristics such as stability, performance and robustness.
Above section present stability term now consider factors for designing compensator such as performance and
robustnesss. For future procedure ϰ∞ theory is considered[1]. By using this theory sensitivity function is given
by,
S(jω) ∞ = maxm S(jω) ≤ Ms (12a)
Where
S s = 1 + K s G(s) −1
(12b)
Which is more acceptable as robustness measure [1],[9]. Here Nyquist plot is used where S(jω) ∞ is inverse of
minimum distance from loop transfer function to critical point(-1,0). Therefore if nyquist plot avoids circle
having centre point (-1,0) and radius 1 by MS then it is said that system is robust related to sensitivity function
which are explained in [1],[8],[9]. To obtain better performance of robustness tools consider another
complimentary sensitivity function,
T(jω) ∞ = maxω T(jω) ≤ MT (13a)
where
T s = K s G(s) 1 + K s G(s) −1
(13b)
Here nyquist plot having centre −MT
2
/(MT
2
− 1),0 and radius (MT/MT
2
− 1) is used. If nyquist plot
avoids circle then it is said that system is robust related to complimentary function. For future work use values
given by Skogestad and Postlethwaite as MS =2 and MT=1.25 and Kristiansson and Lennartson suggest
valuesMS =1.7 and MT=1.4 [1],[9]. After comparison we have final conclusion that values suggested by
Skogestad and Postlethwaite are more accurate.
4.3 Comparison of monotonic and non-monotonic system
It describes the results obtained from proposed methodology and buck regulator which is shown in
section 2. The results can be verified by using MATLAB simulink method. In this case it can be found that the
un-damped frequency is near about or equal to 18 krad/s and left half-plane zero frequency is near about or
equal to 83 krad/s[6]. Assume switching frequency of the converter to be equal to 200 kHz (approximately 1250
krad/s), by using reference it is said that gain cross-over frequency is about fifth times the switching
frequency[3]. Therefore the specified gain cross-over frequency is near about 250 krad/s, from this it concludes
5. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 14 | Page
that system leads to non-monotonic phase where gain-crossover frequency is beyond the left half-plane zero
frequency.
Now the desired phase margin is 40, therefore desired specifications follows the closed loop system
performance having overshoot equal to 25% and a settling time equal to 40 s. In this case the feedback system
must in second order system.
In case of buck regulator non-monotonic phase system is obtained inside desired bandwidth, here PI
controller is superior than PID controller[3]. In this case two parameters for PI controller is studied, first can be
studied by using technique of Phillips and Harbor[2] and another from non-monotonic technique and finally
both results were compared. The values for compensator are shown in Table 1.
Table 1: Comparison of monotonic and non-monotonic compensation
Parameters Monotonic Non-Monotonic
𝐊 𝐏 12.19 14.76
𝐓𝐈[µsec] 5.86 223.05
From Table 1, worst case frequency is 40 krad/s which is close to frequency of buck regulator for non-
monotonic compensation. After comparing values for monotonic and non-monotonic, larger KP and larger TI
(smaller KI) value is found for non monotonic systems. For the monotonic compensation (dashed line) and for
the non-monotonic compensation (solid line), bode plot is presented in fig.3
It should be noticed that from fig.3, bandwidth is same for both compensation, where non-monotonic
system gives larger steady-state error for ramp response and it gives phase margin of at least 40 for all frequency
inside bandwidth whereas monotonic compensation only guarantees the phase margin required for the gain
crossover frequency[4]. It should be remembered that frequencies inside bandwidth only makes control action.
Monotonic compensation does not guarantees the phase margin inside desired bandwidth, since
systems are stable according to Routh–Hurwitz criterion[2],[7]. By using Routh–Hurwitz criterion integral
action time TI is 5.86 microsec and range of gain KP is located in between 0.023 and 2.646. Therefore there is
no real and positive gain able to give the non-monotonically compensated system to instability for the integral
action time equal to 223.05 s
Fig 3. Bode plots for the monotonic compensation (dashed line) and the non-monotonic compensation
(solid line)
From future analysis, monotonic compensation gives two openloop gains which cross the stability limit
of−180°, hence bode plot[1] is not sufficient for analysis. Therefore to check stability limit of both
compensation, we have to use Nyquist plot in frequency response. For the monotonic compensation (dashed
line) and for the non-monotonic compensation (solid line) is presented for Nyquist plot in fig.4
6. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 15 | Page
Fig 4. Nyquist plots for the monotonic compensation (dashed line) and the non-monotonic compensation
(solid line).
Applying stability criterion for both compensation in Nyquist plot, it should be obtained that monotonic
system is not useful for phase margin as it gives one encirclement around the -1 critical point. Whereas it does
not happened in case of non-monotonic phase systems. Fig.4 also shows that robustness boundaries (lighter
lines) of the sensitivity function (smaller circle) withMS =2 and complementary sensitivity function (larger
circle) withMT= 1.25[1]. From above fig.4 it is seen that monotonic systems are not robust regarding to
complimentary sensitivity function MT whreas non-monotonic system is robust in case of sensitivity
functionMS . Hence for non-monotonic system Nyquist plot gives accurate shape and results.
To find out accurate performance use of Step response is necessary, unit step response for the monotonic
compensation (dashed line) and of the non-monotonic compensation (solid line) is shown in Fig. 4. For unit step
response, monotonic phase system use second order system where non-monotonic phase system use first order
system. The settling time for the non-monotonically compensated system is approximately 40 s and for
monotonically compensated system is approximately 60 s. Whereas overshoot in case of non-monotonic system
is smaller than monotonic system, therefore non-monotonic system completes all robustness properties. From
above analysis, it should be noticed that non-monotonic phase gives accurate performance measure and its
Nyquist plot avoids the circle created by the robustness boundary, which the monotonic compensation does
not[1].
Fig 5. Unit step response of the monotonic compensation (dashed line) and the non-monotonic compensation
(solid line).
V. Conclusion
The comparative study of monotonic and non-monotonic phase LTI systems are presented in paper by
using improved analytical PID controller design using gain cross-over frequency and phase margin
specification. Using this methodology accurate results are obtained. Where minimum phase margin is obtained
inside desired bandwidth for closed loop system. Here non-monotonic phase gives more desirable results than
monotonic phase results for closed loop system. For comparative study Bode stability criterion, Nyquist
criterion and Unit step response are used, whereas nyquist plot are used for stability checking and results
obtained by using MATLAB simulink.
7. Comparative Study Of Monotonic And Non-Monotonic Phase Lti Systems Using
DOI: 10.9790/1676-10411016 www.iosrjournals.org 16 | Page
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