This document presents a method for designing a globally linearized controller (GLC) for a first-order nonlinear system with dead time. Two methods are proposed - one based on Smith prediction in the transformed domain, and the other based on Newton's extrapolation method. The GLC design approach transforms the nonlinear system into a linear system through variable transformations. This allows a PI controller to be designed for the linearized system. The performance of the GLC is evaluated through simulations and experiments on a conical tank level process and is found to outperform conventional PI and Smith PI controllers.
State-Space Analysis of Control System: Vector matrix representation of state equation, State transition matrix, Relationship between state equations and high-order differential equations, Relationship between state equations and transfer functions, Block diagram representation of state equations, Decomposition Transfer Function, Kalman’s Test for controllability and observability
State-Space Analysis of Control System: Vector matrix representation of state equation, State transition matrix, Relationship between state equations and high-order differential equations, Relationship between state equations and transfer functions, Block diagram representation of state equations, Decomposition Transfer Function, Kalman’s Test for controllability and observability
Time response of continuous data systems, Different test Signals for the time response, Unit step response and Time-Domain Specifications, Time response of a first-order and second order systems for different test signals, Steady State Error and Error constants, Sensitivity, Control Actions: Proportional, Derivative, Integral and PID control. Introduction to Process Control Systems, Pneumatic hydraulics, Actuators.
Time response of continuous data systems, Different test Signals for the time response, Unit step response and Time-Domain Specifications, Time response of a first-order and second order systems for different test signals, Steady State Error and Error constants, Sensitivity, Control Actions: Proportional, Derivative, Integral and PID control. Introduction to Process Control Systems, Pneumatic hydraulics, Actuators.
실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 스포츠 실시간빙고 방법 실시간빙고 설명 실시간빙고 추천 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 라이브 실시간빙고 사이트 실시간빙고 홍보 실시간빙고 승률 실시간빙고▷아~필승코리아2◁실시간빙고 동영상 실시간빙고 동영상 실시간빙고 실시간 실시간빙고 게임장 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 하는법 실시간빙고 실시간 실시간빙고 중계 실시간빙고 전략 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 전략 실시간빙고 도박 실시간빙고 싸이트 실시간빙고 노하우 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 광고 실시간빙고 온라인 실시간빙고 생중계 실시간빙고 도박 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 노하우 실시간빙고 승률 실시간빙고 동영상 실시간빙고 생중계 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 라이브 실시간빙고 월드컵 실시간빙고 게임 실시간빙고 동영상 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 싸이트 실시간빙고 전략 실시간빙고 하는법 실시간빙고 월드컵 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 게임장 실시간빙고 채팅방 실시간빙고 라이브 실시간빙고 추천인 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 서비스 실시간빙고 전략 실시간빙고 광고 실시간빙고 하는법 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 설명 실시간빙고 홍보 실시간빙고 배트맨 실시간빙고 라이브 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 하는법 실시간빙고 승률 실시간빙고 스포츠 실시간빙고 월드컵 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 실시간 실시간빙고 승률 실시간빙고 라이브 실시간빙고 게임장 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 광고 실시간빙고 서비스 실시간빙고 규칙 실시간빙고 서비스 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 하는법 실시간빙고 하는법 실시간빙고 채팅방 실시간빙고 채팅방 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 월드컵 실시간빙고 싸이트 실시간빙고 추천인 실시간빙고 전략 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 분석 실시간빙고 싸이트 실시간빙고 노하우 실시간빙고 하는법 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 싸이트 실시간빙고 광고 실시간빙고 싸이트 실시간빙고 사이트 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 월드컵 실시간빙고 전략 실시간빙고 싸이트 실시간빙고 라이브 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 배트맨 실시간빙고 전략 실시간빙고 도박 실시간빙고 도박 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 놀이터 실시간빙고 전략 실시간빙고 라이브 실시간빙고 하는법 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 규칙 실시간빙고 사이트 실시간빙고 채팅방 실시간빙고 게임장 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 스포츠 실시간빙고 싸이트 실시간빙고 도박 실시간빙고 추천 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 배트맨 실시간빙고 놀이터 실시간빙고 서비스 실시간빙고 게임 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 스코어 실시간빙고 싸이트 실시간빙고 전략 실시간빙고 동영상 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 동영상 실시간빙고 광고 실시간빙고 분석 실시간빙고 광고 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 동영상 실시간빙고 배우기 실시간빙고 하는곳 실시간빙고 추천 실시간빙고┣〓〓┫▶SX797.COM ◀┣〓〓┫실시간빙고 방법 실시간빙고 생중계 실시간빙고 놀이터 실시간빙고 하는법
SundayKart is a local e-commerce platform that is transforming the shopping experience of consumers like you, by connecting them to local stores.
We aim to become the one-stop shop for all your daily needs. Users can order through the website/app and get everything delivered to their doorstep, quickly.
We offer a wide assortment of groceries, fruits & vegetables, bakery items, flowers and much more.
Sundaykart is providing different types of services to the customers like Electrician, Plumber etc to enrich their lives by resolving their daily problems.
If you are one of the 60% of marketers exploring how to deploy Account-Based Marketing, then you may be wondering where and how to start. Which tactics work and how can your martech stack and marketing database support your ambitious ABM efforts?
In this session, you will hear from ABM practitioners Josh Hill (author of MarketingRockstarGuides.com), Tony Yang (VP of Marketing at Mintigo), and Charlie Liang (Director of Marketing at Engagio) discuss the steps they took to build a martech stack and infrastructure that’s optimized for an ABM strategy. This hands-on session will cover:
How predictive marketing enables ABM
Building a martech infrastructure for ABM
How to structure the right ABM programs
Understanding how analytics change with ABM
Achieving marketing and sales alignment
Mais que faire avec un Smartphone en formation ?
En étant toujours dans la poche de vos apprenants, l'ère du Smart-learning arrive à grand pas pour des solutions adaptées soit complémentaires au e-learning mais également avec une approche en rupture centrée performance métier avec l'aide à la performance professionnelle en ligne. Cette nouvelle approche intéresse déjà les directions opérationnelles pour leurs nomades (commerciaux, techniciens, managers,...)
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
An intelligent hybrid control for paper machine systemeSAT Journals
Abstract
The aim of this paper is to present an intelligent hybrid controller for a paper machine system with ash content and dry weight as
outputs and filler valve and thick stock valve as inputs. Simulation studies have been carried out to check the robust performance
(10% increase in each process gain, 10% increase in each time delay, and 10% decrease in each time constant) of the system. The
improvement in the performance of proposed hybrid controller is compared with the Adaptive-neuro- fuzzy controller and Dahlin
controller and evaluated in terms of ISE.
Index Terms: Dahlin, Neuro-fuzzy, Hybrid and Robust
new optimization algorithm for topology optimizationSeonho Park
authors devise new convex approximation called DQA which utilizes information of two consecutive points at iterates. Also, to guarantee global convergence, filter method is illustrated.
Understanding High-dimensional Networks for Continuous Variables Using ECLHPCC Systems
Syed Rahman & Kshitij Khare, University of Florida, present at the 2016 HPCC Systems Engineering Summit Community Day.
The availability of high dimensional data (or “big data”) has touched almost every field of science and industry. Such data, where the number of variables (features) is often much higher than the number of samples, is now more pervasive than it has ever been. Discovering meaningful relationships between the variables in such data is one of the major challenges that modern day data scientists have to contend with.
The covariance matrix of the variables is the most fundamental quantity that can help us understand the complex multivariate relationships in the data. In addition to estimating the inverse covariance matrix, CSCS can be used to detect the edges in a directed acyclic graph, as opposed to the edges an undirected graph, which CONCORD (presented at the 2015 summit) was used for.
Similar to the CONCORD algorithm, the CSCS algorithm works by minimizing a convex objective function through a cyclic coordinate minimization approach. In addition, it is theoretically guaranteed to converge to a global minimum of the objective function. One of the main advantage of CSCS is that each row can be calculated independently of the other rows, and thus we are able to harness the power of distributed computing.
Syed Rahman
Syed Rahman is a PhD student in the Statistics department at the University of Florida working under the supervision of Dr. Kshitij Khare. He is interested in high-dimensional covariance estimation. In 2015, Syed programmed the CONCORD algorithm in ECL and presented this at the HPCC Systems Engineering Summit.
Kshitij Khare
Kshitij Khare is an Associate Professor of Statistics at the University of Florida. He earned his Ph.D. in Statistics from Stanford University in 2009. He has a variety of interests, which include covariance/network estimation in high-dimensional datasets, and Bayesian inference using Markov chain Monte Carlo methods. One of Dr. Khare's major research focus is development of novel statistical methods and algorithms for "big data" or high-dimensional data.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
ITS World Congress :: Vienna, Oct 2012László Nádai
Control of the emission rate of exhaust fumes as well as vehicle density in various road segments of freeway traffic practically is desirable. For this purpose hydrodynamic macroscopic models are used that approximate the traffic as the motion of some compressible fluid. They normally have analytical ambiguities due to using various finite element approximations of spatial partial differential operators and applying various analytical compressibility models. Further uncertainties stem from the estimation of the model parameters. The suggested approach is able to iteratively and adaptively refine the traffic control based on any version of the possible analytical forms. The controller has to measure vehicle densities and traffic velocities and applies variable traffic signs for prescribing velocities and allowed ingress rate from a ramp as control signals. Since the stationary solutions of the control problem are stable in the region investigated, instead of fast, really dynamic control it applies simple quasi-stationary process model and control that is a common practice in Classical Thermodynamics. The operation of the proposed method is illustrated via simulations.
Finite time control for nonlinear spacecraft attitude based on terminal slidi...ISA Interchange
In this paper, a fast terminal sliding mode control (FTSMC) scheme with double closed loops is proposed for the spacecraft attitude control. The FTSMC laws are included both in an inner control loop and an outer control loop. Firstly, a fast terminal sliding surface (FTSS) is constructed, which can drive the inner loop tracking-error and the outer loop tracking-error on the FTSS to converge to zero in finite time. Secondly, FTSMC strategy is designed by using Lyaponov's method for ensuring the occurrence of the sliding motion in finite time, which can hold the character of fast transient response and improve the tracking accuracy. It is proved that FTSMC can guarantee the convergence of tracking-error in both approaching and sliding mode surface. Finally, simulation results demonstrate the effectiveness of the proposed control scheme.
Implementation of Effective Code Converters using Reversible Logic Gates IJERA Editor
The development in the field of nanometer technology leads to minimize the power consumption of logic
circuits. Reversible logic design has been one of the promising technologies gaining greater interest due to less
dissipation of heat and low power consumption. In the digital design, the code converters are widely used
process. So, the reversible logic gates and reversible circuits for realizing code converters like as Binary to
Gray code, Gray to Binary code, BCD to Excess 3 code, Excess 3 to BCD codes using reversible logic gates is
proposed. Designing of reversible logic circuit is challenging task, since not enough number of gates are
available for design. Reversible processor design needs its building blocks should be reversible in this view the
designing of reversible code converters became essential one. In the digital domain, data or information is
represented by a combination of 0’s and 1’s. A code is basically the pattern of these 0’s and 1’s used to
represent the data. Code converters are a class of combinational digital circuits that are used to convert one type
of code in to another. The proposed design leads to the reduction of power consumption compared with
conventional logic circuits
An optimal general type-2 fuzzy controller for Urban Traffic NetworkISA Interchange
Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the traffic information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study, a combination of the general type-2 fuzzy logic sets and the modified backtracking search algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters of input and output membership functions are optimized simultaneously by the novel heuristic algorithm MBSA. A comparison is made between the achieved results with those of optimal and conventional type-1 fuzzy logic controllers.
Embedded intelligent adaptive PI controller for an electromechanical systemISA Interchange
In this study, an intelligent adaptive controller approach using the interval type-2 fuzzy neural network (IT2FNN) is presented. The proposed controller consists of a lower level proportional - integral (PI) controller, which is the main controller and an upper level IT2FNN which tuning on-line the parameters of a PI controller. The proposed adaptive PI controller based on IT2FNN (API-IT2FNN) is implemented practically using the Arduino DUE kit for controlling the speed of a nonlinear DC motor-generator system. The parameters of the IT2FNN are tuned on-line using back-propagation algorithm. The Lyapunov theorem is used to derive the stability and convergence of the IT2FNN. The obtained experimental results, which are compared with other controllers, demonstrate that the proposed API-IT2FNN is able to improve the system response over a wide range of system uncertainties.
State of charge estimation of lithium-ion batteries using fractional order sl...ISA Interchange
This paper presents a state of charge (SOC) estimation method based on fractional order sliding mode observer (SMO) for lithium-ion batteries. A fractional order RC equivalent circuit model (FORCECM) is firstly constructed to describe the charging and discharging dynamic characteristics of the battery. Then, based on the differential equations of the FORCECM, fractional order SMOs for SOC, polarization voltage and terminal voltage estimation are designed. After that, convergence of the proposed observers is analyzed by Lyapunov’s stability theory method. The framework of the designed observer system is simple and easy to implement. The SMOs can overcome the uncertainties of parameters, modeling and measurement errors, and present good robustness. Simulation results show that the presented estima- tion method is effective, and the designed observers have good performance.
Fractional order PID for tracking control of a parallel robotic manipulator t...ISA Interchange
This paper presents the tracking control for a robotic manipulator type delta employing fractional order PID controllers with computed torque control strategy. It is contrasted with an integer order PID controller with computed torque control strategy. The mechanical structure, kinematics and dynamic models of the delta robot are descripted. A SOLIDWORKS/MSC-ADAMS/MATLAB co-simulation model of the delta robot is built and employed for the stages of identification, design, and validation of control strategies. Identification of the dynamic model of the robot is performed using the least squares algorithm. A linearized model of the robotic system is obtained employing the computed torque control strategy resulting in a decoupled double integrating system. From the linearized model of the delta robot, fractional order PID and integer order PID controllers are designed, analyzing the dynamical behavior for many evaluation trajectories. Controllers robustness is evaluated against external disturbances employing performance indexes for the joint and spatial error, applied torque in the joints and trajectory tracking. Results show that fractional order PID with the computed torque control strategy has a robust performance and active disturbance rejection when it is applied to parallel robotic manipulators on tracking tasks.
Fuzzy logic for plant-wide control of biological wastewater treatment process...ISA Interchange
The application of control strategies is increasingly used in wastewater treatment plants with the aim of improving effluent quality and reducing operating costs. Due to concerns about the progressive growth of greenhouse gas emissions (GHG), these are also currently being evaluated in wastewater treatment plants. The present article proposes a fuzzy controller for plant-wide control of the biological wastewater treatment process. Its design is based on 14 inputs and 6 outputs in order to reduce GHG emissions, nutrient concentration in the effluent and operational costs. The article explains and shows the effect of each one of the inputs and outputs of the fuzzy controller, as well as the relationship between them. Benchmark Simulation Model no 2 Gas is used for testing the proposed control strategy. The results of simulation results show that the fuzzy controller is able to reduce GHG emissions while improving, at the same time, the common criteria of effluent quality and operational costs.
Design and implementation of a control structure for quality products in a cr...ISA Interchange
In recent years, interest for petrochemical processes has been increasing, especially in refinement area. However, the high variability in the dynamic characteristics present in the atmospheric distillation column poses a challenge to obtain quality products. To improve distillates quality in spite of the changes in the input crude oil composition, this paper details a new design of a control strategy in a conventional crude oil distillation plant defined using formal interaction analysis tools. The process dynamic and its control are simulated on Aspen HYSYS dynamic environment under real operating conditions. The simulation results are compared against a typical control strategy commonly used in crude oil atmospheric distillation columns.
Model based PI power system stabilizer design for damping low frequency oscil...ISA Interchange
This paper explores a two-level control strategy by blending a local controller with a centralized controller for the low frequency oscillations in a power system. The proposed control scheme provides stabilization of local modes using a local controller and minimizes the effect of inter-connection of sub-systems performance through a centralized control. For designing the local controllers in the form of proportional-integral power system stabilizer (PI-PSS), a simple and straight forward frequency domain direct synthesis method is considered that works on use of a suitable reference model which is based on the desired requirements. Several examples both on one machine infinite bus and multi-machine systems taken from the literature are illustrated to show the efficacy of the proposed PI-PSS. The effective damping of the systems is found to be increased remarkably which is reflected in the time-responses; even unstable operation has been stabilized with improved damping after applying the proposed controller. The proposed controllers give remarkable improvement in damping the oscillations in all the illustrations considered here and as for example, the value of damping factor has been increased from 0.0217 to 0.666 in Example 1. The simulation results obtained by the proposed control strategy are favorably compared with some controllers prevalent in the literature.
A comparison of a novel robust decentralized control strategy and MPC for ind...ISA Interchange
Abstract: In this work we have developed a novel, robust practical control structure to regulate an industrial methanol distillation column. This proposed control scheme is based on a override control framework and can manage a non-key trace ethanol product impurity specification while maintaining high product recovery. For comparison purposes, an MPC with a discrete process model (based on step tests) was also developed and tested. The results from process disturbance testing shows that, both the MPC and the proposed controller were capable of maintaining both the trace level ethanol specification in the distillate (XD) and high product recovery (β). Closer analysis revealed that the MPC controller has a tighter XD control, while the proposed controller was tighter in β control. The tight XD control allowed the MPC to operate at a higher XD set point (closer to the 10 ppm AA grade methanol standard), allowing for savings in energy usage. Despite the energy savings of the MPC, the proposed control scheme has lower installation and running costs. An economic analysis revealed a multitude of other external economic and plant design factors, that should be considered when making a decision between the two controllers. In general, we found relatively high energy costs favor MPC.
Fault detection of feed water treatment process using PCA-WD with parameter o...ISA Interchange
Feed water treatment process (FWTP) is an essential part of utility boilers; and fault detection is expected for its reliability improvement. Classical principal component analysis (PCA) has been applied to FWTPs in our previous work; however, the noises of T2 and SPE statistics result in false detections and missed detections. In this paper, Wavelet denoise (WD) is combined with PCA to form a new algorithm, (PCA- WD), where WD is intentionally employed to deal with the noises. The parameter selection of PCA-WD is further formulated as an optimization problem; and PSO is employed for optimization solution. A FWTP, sustaining two 1000 MW generation units in a coal-fired power plant, is taken as a study case. Its operation data is collected for following verification study. The results show that the optimized WD is effective to restrain the noises of T2 and SPE statistics, so as to improve the performance of PCA-WD algorithm. And, the parameter optimization enables PCA-WD to get its optimal parameters in an auto- matic way rather than on individual experience. The optimized PCA-WD is further compared with classical PCA and sliding window PCA (SWPCA), in terms of four cases as bias fault, drift fault, broken line fault and normal condition, respectively. The advantages of the optimized PCA-WD, against classical PCA and SWPCA, is finally convinced with the results.
Model-based adaptive sliding mode control of the subcritical boiler-turbine s...ISA Interchange
As higher requirements are proposed for the load regulation and efficiency enhancement, the control performance of boiler-turbine systems has become much more important. In this paper, a novel robust control approach is proposed to improve the coordinated control performance for subcritical boiler-turbine units. To capture the key features of the boiler-turbine system, a nonlinear control-oriented model is established and validated with the history operation data of a 300 MW unit. To achieve system linearization and decoupling, an adaptive feedback linearization strategy is proposed, which could asymptotically eliminate the linearization error caused by the model uncertainties. Based on the linearized boiler-turbine system, a second-order sliding mode controller is designed with the super-twisting algorithm. Moreover, the closed-loop system is proved robustly stable with respect to uncertainties and disturbances. Simulation results are presented to illustrate the effectiveness of the proposed control scheme, which achieves excellent tracking performance, strong robustness and chattering reduction.
A Proportional Integral Estimator-Based Clock Synchronization Protocol for Wi...ISA Interchange
Clock synchronization is an issue of vital importance in applications of wireless sensor networks (WSNs). This paper proposes a proportional integral estimator-based protocol (EBP) to achieve clock synchronization for wireless sensor networks. As each local clock skew gradually drifts, synchronization accuracy will decline over time. Compared with existing consensus-based approaches, the proposed synchronization protocol improves synchronization accuracy under time-varying clock skews. Moreover, by restricting synchronization error of clock skew into a relative small quantity, it could reduce periodic re-synchronization frequencies. At last, a pseudo-synchronous implementation for skew compensation is introduced as synchronous protocol is unrealistic in practice. Numerical simulations are shown to illustrate the performance of the proposed protocol.
An artificial intelligence based improved classification of two-phase flow patte...ISA Interchange
Flow pattern recognition is necessary to select design equations for finding operating details of the process and to perform computational simulations. Visual image processing can be used to automate the interpretation of patterns in two-phase flow. In this paper, an attempt has been made to improve the classification accuracy of the flow pattern of gas/ liquid two- phase flow using fuzzy logic and Support Vector Machine (SVM) with Principal Component Analysis (PCA). The videos of six different types of flow patterns namely, annular flow, bubble flow, churn flow, plug flow, slug flow and stratified flow are re- corded for a period and converted to 2D images for processing. The textural and shape features extracted using image processing are applied as inputs to various classification schemes namely fuzzy logic, SVM and SVM with PCA in order to identify the type of flow pattern. The results obtained are compared and it is observed that SVM with features reduced using PCA gives the better classification accuracy and computationally less intensive than other two existing schemes. This study results cover industrial application needs including oil and gas and any other gas-liquid two-phase flows.
New Method for Tuning PID Controllers Using a Symmetric Send-On-Delta Samplin...ISA Interchange
In this paper we present a new method for tuning PI controllers with symmetric send-on-delta (SSOD) sampling strategy. First we analyze the conditions that produce oscillations in event based systems considering SSOD sampling strategy. The Describing Function is the tool used to address the problem. Once the conditions for oscillations are established, a new robustness to oscillation performance measure is introduced which entails with the concept of phase margin, one of the most traditional measures of relative stability in closed-loop control systems. Therefore, the application of the proposed robustness measure is easy and intuitive. The method is tested by both simulations and experiments. Additionally, a Java application has been developed to aid in the design according to the results presented in the paper.
Load estimator-based hybrid controller design for two-interleaved boost conve...ISA Interchange
This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller. Mathematical proofs are provided with simulations to illustrate the effectiveness and the robustness of the proposed controller despite different disturbances. Furthermore, a fuel cell system supplying a resistive load through a two-interleaved boost converter is also highlighted.
Effects of Wireless Packet Loss in Industrial Process Control SystemsISA Interchange
Timely and reliable sensing and actuation control are essential in networked control. This depends on not only the precision/quality of the sensors and actuators used but also on how well the communications links between the field instruments and the controller have been designed. Wireless networking offers simple deployment, reconfigurability, scalability, and reduced operational expenditure, and is easier to upgrade than wired solutions. However, the adoption of wireless networking has been slow in industrial process control due to the stochastic and less than 100% reliable nature of wireless communications and lack of a model to evaluate the effects of such communications imperfections on the overall control performance. In this paper, we study how control performance is affected by wireless link quality, which in turn is adversely affected by severe propagation loss in harsh industrial environments, co-channel interference, and unintended interference from other devices. We select the Tennessee Eastman Challenge Model (TE) for our study. A decentralized process control system, first proposed by N. Ricker, is adopted that employs 41 sensors and 12 actuators to manage the production process in the TE plant. We consider the scenario where wireless links are used to periodically transmit essential sensor measurement data, such as pressure, temperature and chemical composition to the controller as well as control commands to manipulate the actuators according to predetermined setpoints. We consider two models for packet loss in the wireless links, namely, an independent and identically distributed (IID) packet loss model and the two-state Gilbert-Elliot (GE) channel model. While the former is a random loss model, the latter can model bursty losses. With each channel model, the performance of the simulated decentralized controller using wireless links is compared with the one using wired links providing instant and 100% reliable communications. The sensitivity of the controller to the burstiness of packet loss is also characterized in different process stages. The performance results indicate that wireless links with redundant bandwidth reservation can meet the requirements of the TE process model under normal operational conditions. When disturbances are introduced in the TE plant model, wireless packet loss during transitions between process stages need further protection in severely impaired links. Techniques such as re-transmission scheduling, multi-path routing and enhanced physical layer design are discussed and the latest industrial wireless protocols are compared.
Fault Detection in the Distillation Column ProcessISA Interchange
Chemical plants are complex large-scale systems which need designing robust fault detection schemes to ensure high product quality, reliability and safety under different operating conditions. The present paper is concerned with a feasibility study of the application of the black-box modeling method and Kullback Leibler divergence (KLD) to the fault detection in a distillation column process. A Nonlinear Auto-Regressive Moving Average with eXogenous input (NARMAX) polynomial model is firstly developed to estimate the nonlinear behavior of the plant. Furthermore, the KLD is applied to detect abnormal modes. The proposed FD method is implemented and validated experimentally using realistic faults of a distillation plant of laboratory scale. The experimental results clearly demonstrate the fact that proposed method is effective and gives early alarm to operators.
Neural Network-Based Actuator Fault Diagnosis for a Non-Linear Multi-Tank SystemISA Interchange
The paper is devoted to the problem of the robust actuator fault diagnosis of the dynamic non-linear systems. In the proposed method, it is assumed that the diagnosed system can be modelled by the recurrent neural network, which can be transformed into the linear parameter varying form. Such a system description allows developing the designing scheme of the robust unknown input observer within H1 framework for a class of non-linear systems. The proposed approach is designed in such a way that a prescribed disturbance attenuation level is achieved with respect to the actuator fault estimation error, while guaranteeing the convergence of the observer. The application of the robust unknown input observer enables actuator fault estimation, which allows applying the developed approach to the fault tolerant control tasks.
A KPI-based process monitoring and fault detection framework for large-scale ...ISA Interchange
Large-scale processes, consisting of multiple interconnected sub-processes, are commonly encountered in industrial systems, whose performance needs to be determined. A common approach to this problem is to use a key performance indicator (KPI)-based approach. However, the different KPI-based approaches are not developed with a coherent and consistent framework. Thus, this paper proposes a framework for KPI-based process monitoring and fault detection (PM-FD) for large-scale industrial processes, which considers the static and dynamic relationships between process and KPI variables. For the static case, a least squares-based approach is developed that provides an explicit link with least-squares regression, which gives better performance than partial least squares. For the dynamic case, using the kernel re- presentation of each sub-process, an instrument variable is used to reduce the dynamic case to the static case. This framework is applied to the TE benchmark process and the hot strip mill rolling process. The results show that the proposed method can detect faults better than previous methods.
An adaptive PID like controller using mix locally recurrent neural network fo...ISA Interchange
Being complex, non-linear and coupled system, the robotic manipulator cannot be effectively controlled using classical proportional integral derivative (PID) controller. To enhance the effectiveness of the conventional PID controller for the nonlinear and uncertain systems, gains of the PID controller should be conservatively tuned and should adapt to the process parameter variations. In this work, a mix locally recurrent neural network (MLRNN) architecture is investigated to mimic a conventional PID controller which consists of at most three hidden nodes which act as proportional, integral and derivative node. The gains of the mix locally recurrent neural network based PID (MLRNNPID) controller scheme are initi- alized with a newly developed cuckoo search algorithm (CSA) based optimization method rather than assuming randomly. A sequential learning based least square algorithm is then investigated for the on- line adaptation of the gains of MLRNNPID controller. The performance of the proposed controller scheme is tested against the plant parameters uncertainties and external disturbances for both links of the two link robotic manipulator with variable payload (TL-RMWVP). The stability of the proposed controller is analyzed using Lyapunov stability criteria. A performance comparison is carried out among MLRNNPID controller, CSA optimized NNPID (OPTNNPID) controller and CSA optimized conventional PID (OPTPID) controller in order to establish the effectiveness of the MLRNNPID controller.
A method to remove chattering alarms using median filtersISA Interchange
Chattering alarms are the most found nuisance alarms that will probably reduce the usability and result in a confidence crisis of alarm systems for industrial plants. This paper addresses the chattering alarm reduction using median filters. Two rules are formulated to design the window size of median filters. If the alarm probability is estimated using process data, one rule is based on the probability of alarms to satisfy some requirements on the false alarm rate, or missed alarm rate. If there are only historical alarm data available, the other rule is based on percentage reduction of chattering alarms using alarm duration distribution. Experimental results for industrial cases testify that the proposed method is effective.
Personal Brand Statement:
As an Army veteran dedicated to lifelong learning, I bring a disciplined, strategic mindset to my pursuits. I am constantly expanding my knowledge to innovate and lead effectively. My journey is driven by a commitment to excellence, and to make a meaningful impact in the world.
What is the TDS Return Filing Due Date for FY 2024-25.pdfseoforlegalpillers
It is crucial for the taxpayers to understand about the TDS Return Filing Due Date, so that they can fulfill your TDS obligations efficiently. Taxpayers can avoid penalties by sticking to the deadlines and by accurate filing of TDS. Timely filing of TDS will make sure about the availability of tax credits. You can also seek the professional guidance of experts like Legal Pillers for timely filing of the TDS Return.
Unveiling the Secrets How Does Generative AI Work.pdfSam H
At its core, generative artificial intelligence relies on the concept of generative models, which serve as engines that churn out entirely new data resembling their training data. It is like a sculptor who has studied so many forms found in nature and then uses this knowledge to create sculptures from his imagination that have never been seen before anywhere else. If taken to cyberspace, gans work almost the same way.
Skye Residences | Extended Stay Residences Near Toronto Airportmarketingjdass
Experience unparalleled EXTENDED STAY and comfort at Skye Residences located just minutes from Toronto Airport. Discover sophisticated accommodations tailored for discerning travelers.
Website Link :
https://skyeresidences.com/
https://skyeresidences.com/about-us/
https://skyeresidences.com/gallery/
https://skyeresidences.com/rooms/
https://skyeresidences.com/near-by-attractions/
https://skyeresidences.com/commute/
https://skyeresidences.com/contact/
https://skyeresidences.com/queen-suite-with-sofa-bed/
https://skyeresidences.com/queen-suite-with-sofa-bed-and-balcony/
https://skyeresidences.com/queen-suite-with-sofa-bed-accessible/
https://skyeresidences.com/2-bedroom-deluxe-queen-suite-with-sofa-bed/
https://skyeresidences.com/2-bedroom-deluxe-king-queen-suite-with-sofa-bed/
https://skyeresidences.com/2-bedroom-deluxe-queen-suite-with-sofa-bed-accessible/
#Skye Residences Etobicoke, #Skye Residences Near Toronto Airport, #Skye Residences Toronto, #Skye Hotel Toronto, #Skye Hotel Near Toronto Airport, #Hotel Near Toronto Airport, #Near Toronto Airport Accommodation, #Suites Near Toronto Airport, #Etobicoke Suites Near Airport, #Hotel Near Toronto Pearson International Airport, #Toronto Airport Suite Rentals, #Pearson Airport Hotel Suites
Premium MEAN Stack Development Solutions for Modern BusinessesSynapseIndia
Stay ahead of the curve with our premium MEAN Stack Development Solutions. Our expert developers utilize MongoDB, Express.js, AngularJS, and Node.js to create modern and responsive web applications. Trust us for cutting-edge solutions that drive your business growth and success.
Know more: https://www.synapseindia.com/technology/mean-stack-development-company.html
Putting the SPARK into Virtual Training.pptxCynthia Clay
This 60-minute webinar, sponsored by Adobe, was delivered for the Training Mag Network. It explored the five elements of SPARK: Storytelling, Purpose, Action, Relationships, and Kudos. Knowing how to tell a well-structured story is key to building long-term memory. Stating a clear purpose that doesn't take away from the discovery learning process is critical. Ensuring that people move from theory to practical application is imperative. Creating strong social learning is the key to commitment and engagement. Validating and affirming participants' comments is the way to create a positive learning environment.
VAT Registration Outlined In UAE: Benefits and Requirementsuae taxgpt
Vat Registration is a legal obligation for businesses meeting the threshold requirement, helping companies avoid fines and ramifications. Contact now!
https://viralsocialtrends.com/vat-registration-outlined-in-uae/
Discover the innovative and creative projects that highlight my journey throu...dylandmeas
Discover the innovative and creative projects that highlight my journey through Full Sail University. Below, you’ll find a collection of my work showcasing my skills and expertise in digital marketing, event planning, and media production.
RMD24 | Retail media: hoe zet je dit in als je geen AH of Unilever bent? Heid...BBPMedia1
Grote partijen zijn al een tijdje onderweg met retail media. Ondertussen worden in dit domein ook de kansen zichtbaar voor andere spelers in de markt. Maar met die kansen ontstaan ook vragen: Zelf retail media worden of erop adverteren? In welke fase van de funnel past het en hoe integreer je het in een mediaplan? Wat is nu precies het verschil met marketplaces en Programmatic ads? In dit half uur beslechten we de dilemma's en krijg je antwoorden op wanneer het voor jou tijd is om de volgende stap te zetten.
Cracking the Workplace Discipline Code Main.pptxWorkforce Group
Cultivating and maintaining discipline within teams is a critical differentiator for successful organisations.
Forward-thinking leaders and business managers understand the impact that discipline has on organisational success. A disciplined workforce operates with clarity, focus, and a shared understanding of expectations, ultimately driving better results, optimising productivity, and facilitating seamless collaboration.
Although discipline is not a one-size-fits-all approach, it can help create a work environment that encourages personal growth and accountability rather than solely relying on punitive measures.
In this deck, you will learn the significance of workplace discipline for organisational success. You’ll also learn
• Four (4) workplace discipline methods you should consider
• The best and most practical approach to implementing workplace discipline.
• Three (3) key tips to maintain a disciplined workplace.
[Note: This is a partial preview. To download this presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
Sustainability has become an increasingly critical topic as the world recognizes the need to protect our planet and its resources for future generations. Sustainability means meeting our current needs without compromising the ability of future generations to meet theirs. It involves long-term planning and consideration of the consequences of our actions. The goal is to create strategies that ensure the long-term viability of People, Planet, and Profit.
Leading companies such as Nike, Toyota, and Siemens are prioritizing sustainable innovation in their business models, setting an example for others to follow. In this Sustainability training presentation, you will learn key concepts, principles, and practices of sustainability applicable across industries. This training aims to create awareness and educate employees, senior executives, consultants, and other key stakeholders, including investors, policymakers, and supply chain partners, on the importance and implementation of sustainability.
LEARNING OBJECTIVES
1. Develop a comprehensive understanding of the fundamental principles and concepts that form the foundation of sustainability within corporate environments.
2. Explore the sustainability implementation model, focusing on effective measures and reporting strategies to track and communicate sustainability efforts.
3. Identify and define best practices and critical success factors essential for achieving sustainability goals within organizations.
CONTENTS
1. Introduction and Key Concepts of Sustainability
2. Principles and Practices of Sustainability
3. Measures and Reporting in Sustainability
4. Sustainability Implementation & Best Practices
To download the complete presentation, visit: https://www.oeconsulting.com.sg/training-presentations
"𝑩𝑬𝑮𝑼𝑵 𝑾𝑰𝑻𝑯 𝑻𝑱 𝑰𝑺 𝑯𝑨𝑳𝑭 𝑫𝑶𝑵𝑬"
𝐓𝐉 𝐂𝐨𝐦𝐬 (𝐓𝐉 𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬) is a professional event agency that includes experts in the event-organizing market in Vietnam, Korea, and ASEAN countries. We provide unlimited types of events from Music concerts, Fan meetings, and Culture festivals to Corporate events, Internal company events, Golf tournaments, MICE events, and Exhibitions.
𝐓𝐉 𝐂𝐨𝐦𝐬 provides unlimited package services including such as Event organizing, Event planning, Event production, Manpower, PR marketing, Design 2D/3D, VIP protocols, Interpreter agency, etc.
Sports events - Golf competitions/billiards competitions/company sports events: dynamic and challenging
⭐ 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐝 𝐩𝐫𝐨𝐣𝐞𝐜𝐭𝐬:
➢ 2024 BAEKHYUN [Lonsdaleite] IN HO CHI MINH
➢ SUPER JUNIOR-L.S.S. THE SHOW : Th3ee Guys in HO CHI MINH
➢FreenBecky 1st Fan Meeting in Vietnam
➢CHILDREN ART EXHIBITION 2024: BEYOND BARRIERS
➢ WOW K-Music Festival 2023
➢ Winner [CROSS] Tour in HCM
➢ Super Show 9 in HCM with Super Junior
➢ HCMC - Gyeongsangbuk-do Culture and Tourism Festival
➢ Korean Vietnam Partnership - Fair with LG
➢ Korean President visits Samsung Electronics R&D Center
➢ Vietnam Food Expo with Lotte Wellfood
"𝐄𝐯𝐞𝐫𝐲 𝐞𝐯𝐞𝐧𝐭 𝐢𝐬 𝐚 𝐬𝐭𝐨𝐫𝐲, 𝐚 𝐬𝐩𝐞𝐜𝐢𝐚𝐥 𝐣𝐨𝐮𝐫𝐧𝐞𝐲. 𝐖𝐞 𝐚𝐥𝐰𝐚𝐲𝐬 𝐛𝐞𝐥𝐢𝐞𝐯𝐞 𝐭𝐡𝐚𝐭 𝐬𝐡𝐨𝐫𝐭𝐥𝐲 𝐲𝐨𝐮 𝐰𝐢𝐥𝐥 𝐛𝐞 𝐚 𝐩𝐚𝐫𝐭 𝐨𝐟 𝐨𝐮𝐫 𝐬𝐭𝐨𝐫𝐢𝐞𝐬."
2. 82 Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91
present paper, it is shown that how transforma-
tions may be found which transform the nonlinear
system with dead time into one that is ideally lin-
ear. The approach is based on the hypothesis that a
system which is nonlinear with dead time in its
original variables is linear in some transformation
of the predicted future original variables. Con-
structive methods for finding the appropriate trans-
formations are presented. The design of a control-
ler for the linear transformed system may then be
carried out with a great deal of facility. The result-
Fig. 1. Conceptual configuration of the GLC controller.
ing controller will of course be nonlinear when
recast in terms of the original system variables. In
the present work, the specific problem of a conical
tank level process system having dead time is used
to illustrate the potentials of this approach. An ex- where a and b are constants, v is a state variable,
ample simulation and real time implementation of and g ( • ) is a function to be determined. Differen-
the controller on a conical tank laboratory level tiating Eq. ͑3͒ with respect to t,
process are presented.
dz dg dx
ϭ . ͑5͒
dt dx dt
From Eqs. ͑1͒ and ͑2͒
2. Design of globally linearized controller
„GLC… dx
ϭc 1 f 1 ͑ x ͒ ϩc 2 f 2 „x,u ͑ tϪT d͒ …. ͑6͒
dt
2.1. Variable transformation
Substituting Eq. ͑6͒ in Eq. ͑5͒,
A single-input, single-output nonlinear control
dz dg dg
system with dead time can be represented in gen- ϭc 1 f 1 ϩc 2 f 2 . ͑7͒
eral by dt dx dx
dx Let
ϭF„x,u ͑ tϪT d͒ …, ͑1͒
dt dg
c 1 f 1͑ x ͒ ϭa ͑8͒
where F ( • ) is an arbitrary nonlinear function of x, dx
the system state variable, and u, the control vari- and
able, and T d is the dead time in the process. The
function F„x,u ( tϪT d) … is split up as dg
c 2 f 2 „x,u ͑ tϪT d͒ … ϭb v . ͑9͒
F„x,u ͑ tϪT d͒ …ϭc 1 f 1 ͑ x ͒ ϩc 2 f 2 „x,u ͑ tϪT d͒ …, dx
͑2͒ The nonlinear system is thus mapped to
where f 1 ( x ) is a function of x alone and dz
f 2 „x,u ( tϪT d) … is a function of both x and ϭaϩb v . ͑10͒
u ( tϪT d) . Both f 1 and f 2 are taken to be nonlin- dt
ear. c 1 and c 2 are constants. A linear system may be effectively controlled with
zϭg ͑ x ͒ ͑3͒ a PI controller as in Fig. 1. From Eq. ͑8͒, the trans-
formation g ( x ) which transforms the given non-
is a transformation for mapping the nonlinear sys- linear system with dead time into a linear system
tem F ( • ) to a linear system is
dz
dt
ϭaϩb v , ͑4͒ g͑ x ͒ϭ
a
c1
• ͵ f dxx ͒ .
͑
1
͑11͒
3. Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91 83
2.2. Prediction of process variable and controller
output
A conventional PI controller gives an output
v ( t ) which effectively controls z. The future value
of f 2 is predicted either by using Newton’s method
or by using the transformed model of the system.
Since f 2 is a function of v , once f 2 is predicted, v
can be easily obtained. The nonlinear control law
can be obtained using Eq. ͑12͒.
Fig. 2. Block diagram representation of the nonlinear con-
troller with Newton’s predictor method ͑NEM͒. The PI con-
troller is designed for the linear system ͓Eq. ͑10͔͒. 2.3. Newton’s extrapolation method
Newton’s extrapolation formula, used to predict
the future value, is
Substituting the value of dg/dx from Eq. ͑8͒ into
Eq. ͑9͒ yields f ͑ pϩh ͒ ϭ f ͑ p ͒ ϩhٌ f ͑ p ͒ ϩhigher-order terms,
͑13͒
c 1 f 1 b v ͑ tϩT d͒
u͑ t ͒ϭ . ͑12͒
c 2 a f 2 „x ͑ tϩT d͒ … where f ( pϩh ) is the future value to be predicted
after an interval of h sec and p is the sampling
Let time at which the latest value is available. ٌ is the
difference operator. ٌ f ( p ) is the difference be-
u ͑ t ͒ ϭq ͑ • ͒ , tween the latest sampled value and the previous
sampled value. The number of terms that has to be
where v ( tϩT d) is the predicted manipulated vari- considered in the above formula depends on the
able and f 2 „x ( tϩT d) … is the predicted function of number of past data available and the designer’s
state variable. In deriving Eq. ͑12͒, the specific interest. In their work, only the first two terms are
case of f 2 ( x ) •u ( tϪt d) is considered than considered ͓8͔. This method may be called New-
f 2 „x,u ( tϪt d) …. In general case u has to be solved ton’s extrapolation method ͑NEM͒.
numerically.
Thus a nonlinear controller u ( t ) is designed
based on a variable transformation for the first- 2.4. Variable transformation predictor
order nonlinear process with dead time. The con-
troller performance is tested by simulation of the The nonlinearity in the process and hence in the
conical tank level process. The proposed control- model limits the prediction. The model which is
ler is expected to be highly robust when the oper- used to map the nonlinear process by variable
ating point of the process is shifted over the entire transformation is linear and this model is used
span of the tank. q ( • ) is the transformation which here to predict the future variable as shown in Fig.
transforms the linear controller output in the trans- 3. The configuration is a combination of Smith
formed domain into the nonlinear controller out- predictor and variable transformation and hence
put in the original domain. may be called the variable transformation predic-
A PI controller is designed and interfaced with tor ͑VTP͒. The transfer function model of the
the pseudolinear system shown in Fig. 2. This is transformed pseudolinear system ͑10͒ is
made possible by the use of the transformations z ( s ) / v ( s ) ϭb/s. The transfer function model b/s
g ( x ) and u ( t ) . x * is the set point and z * is the set will give the predicted transformed process vari-
point in the transformed domain. Thus the entire able z Ј . The model prediction error e m is the dif-
design procedure boils down to the determination ference between the predicted output and the
of g ( x ) to compute the corresponding u ( t ) by us- transformed process variable z. e m is added in the
ing Eq. ͑12͒. feedback path as an additional error.
4. 84 Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91
Fig. 3. Block diagram representation of the variable trans-
formation predictor. The PI controller is designed for the
linear system ͓Eq. ͑10͔͒. Fig. 4. Block diagram of the Smith PI controller.
but practically it is found that selection of large
3. Application of GLC to conical tank level
values of a and b end up with overflow error in the
process
transformed variable.
The transfer function of Eq. ͑15͒ is
The mathematical model of the conical tank liq-
uid level system considered for the study is ex- G ͑ s ͒ ϭb/s. ͑16͒
pressed as
The forward path transfer function of the closed-
dh ͓ u ͑ tϪT d͒ ϩu d͑ tϪT d͒ Ϫc ͱh ͔ loop system with a PI controller is
ͫ ͬ
ϭ , ͑14͒
dt R2 2 G f͑ s ͒ ϭbK c͑ 1ϩT is ͒ /T is 2 . ͑17͒
2h
H T i and K c can be obtained by assuming a closed-
where H, R, c are total height, top radius, and out- loop time constant and damping factor ͓9͔. Inter-
flow valve coefficient of the conical tank, respec- estingly, the tuning parameters are independent of
tively. h, u, and u d are liquid level, inflow rate, and local time constant and local gain of the process.
disturbance of the conical tank level process, re- The transformation which transforms the present
spectively. The transformation g ( h ) transforms process in to a linear system is
the nonlinear system represented by Eq. ͑14͒ into
Ϫ2a⌸R 2
a linear system. The transformed system is a g͑ h ͒ϭ h 5/2. ͑18͒
pseudolinear system, whose mathematical model 5H 2 c
is
4. Tuning of controllers
dz
ϭaϩb v . ͑15͒
dt The responses are compared with a conventional
The values of a and b are assumed as Ϫ0.7657 PI controller tuned about nominal operating point
and 0.0177, respectively. Mathematically there is of 39%. The time constant and gain of linearized
no restriction on the selection of values of a and b model are 76 sec and 1.2, respectively. The pro-
cess dead time is 32 sec. The Ziegler and Nichols
Table 1 Table 2
ISE of Regulatory responses for 15% decrease in load. ISE of Regulatory responses for 15% increase in load.
Operating ZN Smith Operating ZN Smith
point PI PI GLC point PI PI GLC
39% 1285 3269 928 39% 1236 3367 807
24% 2324 2762 1492 24% 1780 2991 2162
54% 1224 3740 518 54% 1221 3779 448
5. Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91 85
Table 3
ISE of servo responses for 20% increase in set point.
Operating ZN Smith
point PI PI GLC
39% 23670 35480 16090
24% 19260 27530 15780
54% 32030 47660 16260
͑ZN͒ tuning parameters for the linearized model
are K cϭ0.95 and T iϭ0.020. The tuning param-
eters for the Smith PI controller as shown in Fig. 4
are based on Haalman’s tuning rule. They are K c
ϭ0.5747 and T iϭ0.022 ͓10͔. Similarly for both
GLC’s are K cϭ2.87 and T iϭ0.025.
The simulation and experimentation are carried
out by taking 39% as nominal level. 24% and 54%
are other operating points used to test the robust- Fig. 5. Regulatory responses for a 15% decrease in load at
ness of the controller tuned at 39% nominal level. 39% nominal operating point.
The integral square error ͑ISE͒ values are pre-
sented in the Tables 1– 4. Regulatory responses for
a 15% decrease in load at nominal operating point a better response ͑26% lesser ISE͒ than the con-
39% ͑refer to Fig. 5͒ show that the proposed con- ventional Smith predictor. The ZN-PI controller
troller gives an improved response ͑28% lesser gives an oscillatory response. Regulatory re-
ISE͒ while the conventional Smith predictor sponses for a 15% decrease in load at 54% oper-
͑150% higher ISE͒ gives a poorer performance ating point but tuned at 39% ͑refer to Fig. 9͒ show
than the ZN-PI controller. that the proposed controller gives an improved
Regulatory responses for a 15% increase in load performance ͑58% lesser ISE͒ while the conven-
at nominal operating point 39% ͑refer to Fig. 6͒ tional Smith predictor ͑205% higher ISE͒ provides
show that the proposed controller improves the re- a poorer performance than the ZN-PI controller.
sponse ͑35% lesser ISE͒ while the conventional
Smith predictor ͑172% higher ISE͒ gives a poorer
performance than the ZN-PI controller.
Regulatory responses for a 15% decrease in load
at 24% operating point but tuned at 39% ͑refer to
Fig. 7͒ show that the proposed controller provides
a better response ͑36% lesser ISE͒ than the con-
ventional Smith predictor ͑19% higher ISE͒. The
ZN-PI controller gives an oscillatory response.
Regulatory responses for a 15% increase in load
at 24% operating point but tuned at 39% ͑refer to
Fig. 8͒ show that the proposed controller provides
Table 4
ISE of servo responses for 20% decrease in set point.
Operating ZN Smith
point PI PI GLC
39% 46920 28900 20030
24% 18918 14260 10930
Fig. 6. Regulatory responses for a 15% increase in load at
54% 28980 36270 18420
39% nominal operating point.
6. 86 Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91
Fig. 7. Regulatory responses for a 15% decrease in load at Fig. 9. Regulatory responses for a 15% decrease in load at
24% operating point. 54% operating point.
Regulatory responses for a 15% increase in load proved response ͑31% lesser ISE͒ than the con-
at 54% operating point but tuned at 39% ͑refer to ventional Smith predictor. The ZN-PI controller
Fig. 10͒ show that the proposed controller im- provides an oscillatory response. Servo responses
proves the performance ͑63% lesser ISE͒ while for a 20% increase in the set point at nominal op-
the conventional Smith predictor ͑209% higher erating point 39% ͑refer to Fig. 12͒ show that the
ISE͒ gives a poorer response than the ZN-PI con- proposed controller improves the response ͑32%
troller. lesser ISE͒ while the conventional Smith predictor
Servo responses for a 20% decrease in the set ͑50% higher ISE͒ gives a poorer performance than
point at nominal operating point 39% ͑refer to Fig. the ZN-PI controller.
11͒ show that the proposed controller gives an im-
Fig. 8. Regulatory responses for a 15% increase in load at Fig. 10. Regulatory responses for a 15% increase in load at
24% operating point. 54% operating point.
7. Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91 87
Fig. 11. Servo responses for a 20% decrease in set point at
39% nominal operating point. Fig. 13. Servo responses for a 20% decrease in set point at
24% operating point.
Servo responses for a 14% decrease in the set domain are lesser than the tolerance that can be
point at 24% operating point but tuned at 39% handled by the computer.
͑refer to Fig. 13͒ show that the proposed controller Servo responses for a 20% increase in set point
improves the response ͑33% lesser ISE͒ more than at 24% operating point but tuned at 39% ͑refer to
the conventional Smith predictor. The ZN-PI con- Fig. 14͒ show that the proposed controller im-
troller gives an oscillatory response. At this oper- proves the response ͑18% lesser ISE͒ while the
ating point it is not possible to decrease the set conventional Smith predictor ͑43% higher ISE͒
point greater than 14% because of numerical gives a poorer performance than the ZN-PI con-
round-off error. Some values in the transformed troller.
Fig. 12. Servo responses for a 20% increase in set point at Fig. 14. Servo responses for a 20% increase in set point at
39% nominal operating point. 24% operating point.
8. 88 Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91
Fig. 15. Servo responses for a 20% decrease in set point at
54% operating point.
Fig. 17. Servo responses of conical tank level process for
Ϫ8% step change at nominal operating point 39% using
GLC ͑VTP͒ and GLC ͑NEM͒ with the same PI settings.
Servo responses for a 20% decrease in set point
at 54% operating point but tuned at 39% ͑refer to
Fig. 15͒ show that the proposed controller im- ler and the conventional Smith predictor ͑49%
proves the response ͑36% lesser ISE͒ while the higher ISE͒ provides a very poor response.
conventional Smith predictor ͑25% higher ISE͒ The servo responses of the conical tank level
gives a poorer response than the ZN-PI controller. process for a 8% decrease in set point at the nomi-
Servo responses for a 20% increase in set point at nal operating point of 39% using GLC
54% operating point but tuned at 39% as in Fig. controllers—one with NEM prediction and the
16 show that the proposed controller improves the other with proposed VTP prediction but both with
response ͑51% lesser ISE͒ than the ZN-PI control- same tuning parameters—are shown in Fig. 17.
The response given by NEM has slight oscilla-
tions. The magnitude of oscillations increases as
the step magnitude increases. This indicates that
the prediction by NEM is very poor compared
with the proposed GLC with VTP.
Figure 18 shows the experimental servo re-
sponses for various set point changes at 39%
nominal level. The responses are slightly oscilla-
tory. Figures 19 and 20 show the experimental
regulatory responses for various magnitudes of
load changes at the nominal operating point. The
regulatory responses are found to have small os-
cillations as compared to the servo responses. Fig-
ure 21 shows a block diagram of the experimental
setup.
5. Conclusion
Fig. 16. Servo responses for a 20% increase in set point at A nonlinear controller is designed based on the
54% operating point. variable transformation for the first-order nonlin-
9. Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91 89
Fig. 18. Experimental servo responses of conical tank level process for set point changes at nominal operating point 39%
using GLC ͑VTP͒.
ear process with dead time. The performances of worse when the operating point is shifted to 54%.
proposed GLC ͑VTP͒ are tested by simulation and On the other hand, the proposed controller gives
compared with ZN PI and Smith PI controllers. better dynamics.
The ZN PI controller gives an oscillatory response Consider the regulatory responses at 24% oper-
for decrease in set point even at a nominal operat- ating point for decrease in load as shown in Fig. 7.
ing point. The situation becomes worse when the The ZN-PI controller gives a highly oscillatory re-
operating point is shifted to 24%. For any increase sponse. On the other hand, Smith PI and GLC give
in the set point the Smith PI controller gives a an oscillation free response. Similarly, consider
very poor response due to a very small dead time the regulatory responses at 24% operating point
to time constant ratio. This situation becomes for an increase in load as shown in Fig. 8. Here
Fig. 19. Experimental regulatory responses of conical tank level process for increase in load changes at nominal operating
point 39% using GLC ͑VTP͒.
10. 90 Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91
Fig. 20. Experimental regulatory responses of conical tank level process for decrease in load changes at nominal operating
point 39% using GLC ͑VTP͒.
also the ZN-PI controller gives a highly oscillatory controller gives oscillatory responses and the
response but the Smith PI gives an oscillation-free Smith PI gives sluggish responses, GLC gives os-
response. GLC gives an oscillatory response but cillation free responses with quick rise time. The
quickly settles unlike that of the ZN-PI controller. simulation results show the robustness of the
In this case the drawback with the GLC is the GLC.
large undershoot. But it has less ISE than that of The proposed controller outperforms the Smith
Smith PI. Consider the regulatory responses at PI and the ZN-PI controllers when the operating
54% operating point ͑refer to Figs. 9 and 10͒. The point of the process is shifted over the entire span
Smith PI controller gives a large undershoot and a of the tank. While comparing VTP and NEM, VTP
large overshoot compared to that of the ZN-PI gives better dynamics than NEM. As a future
controller. But GLC gives a very small overshoot work, the GLC can be tested on other nonlinear
and undershoot compared to that of the ZN-PI systems; the work in this direction is ongoing.
controller. Consider the servo responses at 39%
and 24% ͑refer to Figs. 11 and 13͒. The ZN-PI Acknowledgments
We are grateful to Professor K. Ethirajulu for his
constant encouragement and providing the facili-
ties. We thank Professor P. Dhananjayan for his
encouragement.
References
͓1͔ Meyer, C., Seborg, D. E., and Wood, R. K., A com-
parison of the Smith predictor and conventional feed-
back control. Chem. Eng. Sci. 31, 775–778 ͑1976͒.
͓2͔ Hagglund, T., A predictive PI controller for processes
with long dead times. IEEE Control Syst. Mag. 12 ͑1͒,
57– 60 ͑1992͒.
͓3͔ Tan, K. K., Lee, T. H., and Leu, F. M., Predictive PI
versus Smith control for dead-time compensation. ISA
Trans. 40, 17–29 ͑2001͒.
͓4͔ Schneider, D. M., Control of process with time delays.
IEEE Trans. Ind. Appl. 24 ͑2͒, 186 –191 ͑1988͒.
͓5͔ Ray, W. H., Advanced Process Control. McGraw-Hill,
Fig. 21. Block diagram of experimental setup. New York, 1981.
11. Anandanatarajan, Chidambaram, Jayasingh / ISA Transactions 44 (2005) 81–91 91
͓6͔ Vrecko, D., Vrancic, D., Juricic, D., and Strmcnik, S.,
A new modified Smith predictor: The concept, design M. Chidambaram obtained
and tuning. ISA Trans. 40, 111–121 ͑2001͒. his B.E. ͑Chemical͒ from An-
namalai University, M.E.
͓7͔ Ogunnalke, B. A., Controller design for nonlinear pro- ͑Chemical͒ and Ph.D. from In-
cess systems via variable transformations. Ind. Eng. dian Institute of Science in
Chem. Process Des. Dev. 25, 241–248 ͑1986͒. 1977 and 1984, respectively.
͓8͔ Chidambaram, M., Anandanatarajan, R., and Jayas- He was faculty member in IIT-
ingh, T., Controller design for nonlinear process with Bombay during 1984 to 1991.
dead time via variable transformations. Proceedings of Since September 1991 he has
been a faculty member in IIT-
the International Symposium on Process Systems En- Madras. He had been head of
gineering and Control ͑ISPSEC’03͒, IIT, Mumbai, the Department of Chemical
2003, pp. 223–228. Engineering during the period
͓9͔ Chidambaram, M., Applied Process Control. Allied October 2000 to October 2003.
Publishers, New Delhi, India, 1998. He has authored three books: Nonlinear Process Control. John Wiley,
͓10͔ Tian, Y. C. and Gao, F., Double-controller scheme for 1996; Applied Process Control. Allied Publishers, 1998; Computer
Control of Processes. Narosa Publishers, 2002. He has published 135
control of processes with dominant delay. IEE Proc.: research publications in journals and 45 papers in conferences pro-
Control Theory Appl. 145 ͑5͒, 479– 484 ͑1998͒. ceedings. His areas of interest in process control are PID control, relay
tuning, and nonlinear control.
R. Anandanatarajan ob-
tained his B.Sc. ͑Mathematics͒
from Madras University in
1984, Bachelor degree in Elec- T. Jayasingh obtained his
trical from the Institution of Ph.D. in Control and Instru-
Engineers ͑India͒ in 1989, mentation from IIT-Delhi. He
M.Sc. ͑Mathematics͒ and M.E. has more than two decades of
͑Process control and Instru- experience in teaching and re-
mentation͒ from Annamalai search at Anna University,
University in 1994 and 1998, Chennai, India. Presently he is
respectively, Ph.D. from Anna a visiting professor at St.
University in 2003. Presently Xaviers College of Engineer-
he is assistant professor of the ing, Nagercoil, India. His areas
Department of Instrumentation of interest include process con-
Engineering, Pondicherry Engineering College. He has authored two trol, computer based instru-
books titled Signals & Systems and Computer Peripherals and Inter- mentation, and sensor model-
facing. ing.