WSEAS CONFERENCES. WSEAS, Unifying the Science

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 Volume 3, 2008
Print ISSN: 1991-8763
E-ISSN: 2224-2856








Issue 1, Volume 3, January 2008

Title of the Paper:  Genetic Algorithm Optimization of Fuel Consumption in Compressor Stations


Authors: B. Fahimnia, R. Molaei, M. Ebrahimi

Abstract: Natural gas passing through pipelines is transported via compressor stations. These stations are usually installed at above 60 miles away from intervals in order to overwhelm the pressure loss generated through the friction or the heat exchanging. Different compressors have been utilized in these stations to acquire the constraint gradient pressure and maintain the required mass flow rate at the delivery. A considerable proportion of the transported gas is however consumed to supply the drift force. Since currently millions of MMSCFD gases are transferred between countries, it seems indispensable to propose a precise model to minimize the consumed fuel and to stumble on suitable decision-making variables. This paper analyzes non-linear mathematical relationships which are required to evaluate the steady, isothermal, one-dimensional and compressible flow inside the pipes. In the next stage, the study establishes the equations associated to the compressor performance and it finally evaluates the rate of fuel consumption in the power generator. The activities are divided into two categories: a) simulation by means of the computational modules, related to the fluid specifications and the main components of the transmission system, b) amelioration through the exploitation of the optimization methodology using genetic algorithms. Spread sheets are utilized as useful tools to establish a relationship among the aforementioned sections and the analysis of the system comportment. The optimization modeling aims to improve the fuel consumption in the compressor stations available in the network commensurate with the stipulations of the transmission system.

Keywords: Optimization, Genetic Algorithm, Compressor Station, Fuel Consumption, Spread Sheets

Title of the Paper: The Study of Novel Detection Approach for OCS Dynamic Parameters of High-speed Electrified Railway


Authors: Chen Tanglong, Ma Fengchao, Zhou Yan

Abstract: This paper starts with dynamic response of pantograph slider, and computes the dynamic parameters of pantograph-catenary system such as contact force, hard spot, pull-off value and contact wire height by utilizing the transfer function matrix gained beforehand and the displacements of pantograph slider measured with the laser range sensors configured at the low voltage side. The paper also deducts the numerical algorithm of response matrix and transfer function matrix, demonstrates the feasibility of reducing the number of laser range sensors, and verifies its effectiveness by simulation with a simple example.

Keywords: OCS (Overhead Contact System); Pantograph; System Response; Contact Force; Pull-off Value; Hard Spot; Contact Wire Height; Laser Testing Displacement

Title of the Paper: Original Method for Stability Analysis of Mechatronic Systems with Asynchronous Machines


Authors: Sorin Enache, Aurel Campeanu, Ion Vlad, Monica Adela Enache

Abstract: This paper details an original method for the stability analysis of mechatronic systems driven by asynchronous machines. The mathematical basis of the method and a few characteristics obtained with an adequate Matlab program are presented. The windows of the program for monitoring of the experimental tests are also depicted. Finally a series of experimental tests and the conclusions confirming the validity of the proposed method are presented.

Keywords: stability, mechatronic system, asynchronous machine, variable frequency, parameters, software.

Title of the Paper: Evaluation of Hand Grasping by Instrumented Glove


Authors: Tamara Supuk, Tadej Bajd, Vlasta Zanchi

Abstract: In this paper the evaluation of effectivenes of instrumented glove in measurement of hand opening and preshaping during reach-to-grasp movement is described. In the experiment presented in this work the reach-to-grasp movement of one healthy subject was measured by two different types of motion-tracking devices (3D optical system, Optotrak, and commercial instrumented glove, 14 sensors Ultra Data Glove) with the aim to answer if the rather simple glove-system can substitute complex and expensive optical system in assessment of hand preshaping during reach-tograsp.

Keywords: hand kinematics, reach-to-grasp movements, hand preshaping, hand model, instrumented glove, rehabilitation

Title of the Paper: Resonance at Motion of a Body in the Mars's Atmosphere under Biharmonical Moment


Authors: Vladimir S. Aslanov

Abstract: An uncontrolled motion of a reentry vehicles in the rarefied Mars's atmosphere is investigated. Such reentry vehicle has small lengthening and a blunted form for effective braking [1]. This type of Lander can have three balancing positions of a spatial angle of attack: α = 0, α* != 0, α* = π depending on the position of the center mass. The change of a dynamic pressure the descent into the atmosphere can lead to resonance. It is shown, that the numerical integration of motion equations does not give reliable results due to the probabilistic character of transients with related to resonance. The conditions of movement stability are received identified for various areas of movement under resonance. The suggestion is to calculate the top and bottom parameters of movement using averaged equations. The research shows that the resonance could cause the accident the Beagle 2 Lander.

Keywords: Uncontrolled Reentry Vehicle, Resonance, Stability, Separatrice, Atmosphere, Mars

Title of the Paper: Experimental Design and Models of Power System Optimization and Control


Authors: R. C. Berredo, L. N. Canha, P. Ya. Ekel, L. C. A. Ferreira, M. V. C. Maciel

Abstract: This paper reflects results of research into the use of factorial experimental design for rational constructing sensitivity models as well as functionally oriented models for system optimization and control. The questions of overcoming difficulties of statistical evaluating the results of experiments with models of systems, but not real systems are discussed. The results of the paper are of a universal character and are illustrated by applications to power engineering problems: coordinated voltage and reactive power control in power systems in regulated and deregulated environments, based on fuzzy logic technology with applying diverse types of sensitivity indices, and monocriteria and multicriteria optimization of network configuration in distribution systems with constructing functionally oriented models to evaluate power system reaction.

Keywords: Sensitivity Models, Functionally Oriented Models, Factorial Experimental Design, Fuzzy Logic Based Voltage and Reactive Power Control, Distribution Network Reconfigutration.

Title of the Paper: Synthesis of Attitude Motion of Variable Mass Coaxial Bodies


Authors: Anton V. Doroshin

Abstract: This work involves the research of a motion of a mechanical system consisting from coaxial bodies of variable mass in a translating coordinate system. The author gives a theorem on the change in the angular momentum of a system of variable mass coaxial bodies with respect to translating axes. The dynamic equations of motion are constructed using the example of two coaxial bodies. The modification of mass parameters of coaxial bodies (mass, moments of inertia) causes nontrivial changes of system angular motion. The article describes a special developed method for qualitative phase space analysis, based on the evaluation of a phase trajectory curvature. The method suggested makes it possible to determine the phase trajectory shape and to synthesize conditions for special motion modes realization (for example, nutation angle monotonous diminution or magnification). The results obtained can be used to describe the motion of a coaxial dual-spin spacecraft, performing active maneuvers with a change in mass.

Keywords: Coaxial Bodies, Unbalanced Gyrostat, Dual-Spin Spacecraft, Variable Mass, Active Maneuvers, Attitude Motion, Qualitative Method, Phase Trajectory Curvature

Title of the Paper: One Type of Controller Design for Delayed Double Integrator System


Authors: Katarina Zakova

Abstract: The aim of this paper is to present a constrained pole assignment controller that is based on the analysis of optimal settings for the double integrator system. It takes into account parasitic delays in the control structure and constraints imposed on the control signal. In addition, one can find here approximation procedure resulting to the models that were used at the controller design. The whole design is illustrated on two examples.

Keywords: Pole assignment control, constraints, saturation, double integrator model, delays, approximation.

Issue 2, Volume 3, February 2008

Title of the Paper:  Novel Approach for Detection and Tracking of Explosive Carrying Mobile Humans with Odor-Sensor based Multisensor Networks


Authors: Ahmet Kuzu, Metin Gokasan, Seta Bogosyan

Abstract: In this study, a distributed system which could be used to detect and track an explosive carrying mobile human is designed. As a novel approach to existing odor detection and tracking methods, a technique which combines odor and sound detection is proposed for increased accuracy. To this aim, a MEMS sensor network including a pressure sensor, an accelerometer, a microphone, an odor sensor and electronic unit is proposed. For the electronic unit of this system a sensor network and least square estimation based sensor fusion algorithm is developed and simulated. The results are evaluated with respect to various paths of two humans, one carrying the explosive. The results show that odor sensing alone is not sufficient for the accurate determination of the odor track, and that by adding other conventional tracking methods, accuracy could be increased.

Keywords: Odor, Tracking, Sensor networks, Sensor fusion, Least squares, Explosive

Title of the Paper: A Solution to the Continuous and Discrete-Time Linear Quadratic Optimal Problems


Authors: Corneliu Botan, Florin Ostafi

Abstract: The paper establishes a non-variational procedure in order to obtain the solution to an optimal control problem. The optimal control refers to a quadratic criterion with finite final time, regarding a time-variant linear system, for continuous and discrete time cases. The proposed solution is more convenient for implementation by comparison with the classical ones. The indicated optimal controller is advantageous especially in the time-invariant case. New solutions to Riccati differential / difference equations are also presented.

Keywords: optimal control, linear quadratic, finite final time, continuous and discrete time, Riccati equation

Title of the Paper: Specification of a Multiagent System for Planning and Management of the Production Factors for Automation based on the SCDIA Framework and MASINA Methodology


Authors: Jose Aguilar, Mariela Cerrada, Francisco Hidrobo, Jorge Chacal, Cesar Bravo

: In this work, we propose a general reference model for planning and production factors management. Then, such a model is applied for proposing a system for the ERP problem for the automation applications. This multiagent system is specified in the framework of the SCDIA reference model by using the MASINA Methodology.

Keywords: Industrial Automation, Enterprise Resource Planning (ERP), Multiagent Systems (MAS)

Title of the Paper: Optimal Adaptive Fuzzy Control for a Class of Unknown Nonlinear Systems


Authors: I. Lagrat, A. El Ougli , I. Boumhidi

Abstract: In this paper, we present an optimal adaptive fuzzy controller for a class of nonlinear systems with unknown nonlinear dynamics. The strategy of control is based on the fuzzy systems and linear matrix inequalities (LMI). The adaptive fuzzy logic system is used to approximate the unknown dynamics; we exploit the linear structure of a Takagi-Sugeno fuzzy system with constant conclusion to design an indirect adaptive fuzzy controller. The auxiliary compensation control is added to attenuate the influence of external disturbances and to remove fuzzy approximation error. The design of the auxiliary control relies on LMI and the Lyapunov technique for achieving stability and specified performance. The adaptation laws of the adjustable parameters are deduced from the stability analysis, in the sense of Lyapunov, to get a more accurate approximation level. Simulation results are given to illustrate the tracking performance.

Keywords: Nonlinear systems, Adaptive control, Fuzzy systems, Takagi-Sugeno Fuzzy Model, LMI, Lyapunov Approach.

Title of the Paper: Speed-Sensorless Nonlinear Predictive Control of a Squirrel Cage Motor


Authors: I. I. Siller-Alcala, M. Abderrahim, J. Jaimes-Ponce, R. Alcantara-Ramirez

Abstract: This paper presents a nonlinear generalised predictive control scheme for a squirrel cage motor without speed sensor. Some of the difficulties faced are due to uncertainties in the parameters measurements, high cost to obtain state measurements in addition to the inherently non-linear behaviour. The control scheme presented is composed of a positioning predictive control and an open loop observer used to obtain state measurements. The proposed control scheme allows a simple and straightforward implementation. The effectiveness of this control algorithm has been successfully verified through simulations.

Keywords: Nonlinear System, Predictive Control, Induction Motor, Speed-sensorless control, Open loop observer.

Title of the Paper: The Simulation Hybrid Fuzzy Control of SCARA Robot


Authors: Marius-Constantin Popescu, Ilie Borcosi Onisifor Olaru, Luminita Popescu, Florin Grofu

Abstract: This paper presents the simulation of a Hybrid Fuzzy Controller suitable for industrial applications. The developed Hybrid Fuzzy Controller consists of a weighted combination of the Direct Fuzzy Controller and Indirect Fuzzy Controller and a gradually activated supervisory controller. The unique feature of the Hybrid Fuzzy Controller is that no mathematical models of the plant are required and the proposed controller is able to adequately estimate the bound functions on-line, which are required for the determination of the supervisory controller. The supervisor controller in the sense that all signals are bounded guarantees global stability of the closed-loop system. The approach of rapid prototyping is utilized to implement the Hybrid Fuzzy Controller so as to control a Selectively Compliance Assembly Robot Arm. Simulink, an interactive graphical software for simulating dynamic systems, is used to model, simulate and analyse the dynamic system.

Keywords: SCARA Robot, Simulink, Hybrid Fuzzy Controller

Title of the Paper: Conventional Control and Fuzzy Control Algorithms for Shape Memory Alloy based Tendons Robotic Structure


Authors: Bizdoaca Nicu-George, Petrisor Anca, Bizdoaca Elvira

Abstract: Shape memory alloy offer an interesting solution, using the shape transformation of the wire/structure in the moment of applying a thermal type transformation able to offer the martensitic temperature. This thermal transformation can be inducted using electrical current and a suitable control strategy. In order to assure an efficient control of robotics SMA actuator, a mathematical model and numerical simulation of the resulting model is required. For an efficient study a Simulink block is developed (block for user configurable shape memory alloy material). Due a particular possibility SMA actuator connection, a modified dynamics for wire or tendon actuation is presented. The control possibilities are explored: PI, PD,PID and fuzzy logic controller are connected to the single link SMA actuation. Experimental results and numerical simulations are presented and observations are formulated.

Keywords: smart materials, shape memory alloy, robotics, conventional control, fuzzy logic, numerical simulation

Title of the Paper: Model-based Control and Learning Control Method for Automobile Idle Speed Control using Electric Throttle


Authors: Teruji Sekozawa

Abstract: Recently, it has become important to reduce the fuel consumption of automobile engines in order to reduce the amount of CO2 emission. Reduced consumption can be achieved by reducing the idle rotation speed. However, the idling stability at low idle speeds tends to be worse than that at higher idle speeds. Thus, more accurate idle speed control is required. In the present paper, we propose an engine model-based feed-forward idle control system. The model-based control system is demonstrated to achieve better control results. In addition, aging and environmental changes (such as temperature reduction) vary with the torque required for driving in-vehicle equipments and cause a deterioration of control for maintaining the idle speed. Regarding this problem, a new learning control method is developed and applied to an actual vehicle to verify that controllability can be improved.

Keywords: Idle speed control, Engine model, Feed-forward control, Electric throttle system, Model-based control, Environmental changes, Learning control

Issue 3, Volume 3, March 2008

Title of the Paper: Performance Evaluation of Static Transfer Switch


Authors: Ramesh Pachar, Harpal Tiwari

Abstract: This paper investigates the performance of GTO switches based STS system for improving the power quality of a sensitive three-phase RL load. Performance of the proposed system is compared with IEEE Benchmark System (STS-1). Extensive simulations are carried out to validate the use of GTO switches in medium voltage systems to achieve a lesser transfer time in network reconfiguration. Performance evaluation of GTO based STS system is carried out under various faults/disturbance conditions. Simulations are performed using simulink tool of MATLAB software package.

Keywords: Power Quality, Static Transfer Switch, Preferred Source, Alternate Source, Transfer Time, Detection Time, Sensitive load, Control Logic.

Title of the Paper: Simulation of n-r Robots


Authors: Popescu Marius-Constantin, Borcosi Iilie, Olaru Onisifor, Antonie Nicolae

: Modelling and simulation of n-DOF robots with revolute joints are presented in the paper. First, numerical effective equations to solve the direct kinematics of n-degree-of-freedom robots are derived. Following this, the dynamic model based on Lagrangian equation is developed. In the model the characteristics of robots are utilized and therefore the complexity of the model is increasing slower with the number of degrees of freedom compared with the general type of manipulators. Next, some cost functions for n-R robots and their gradients are presented. The derived models represent the basis of the software package "Robotic Toolbox" implemented in Matlab. The package allows the user to create and simulate different systems considering robots. Matlab functions and Simulink blocks provided include forward kinematics, dynamics and several utility functions.

Keywords: Modelling; Redundant robots; Simulation n-r robots.

Title of the Paper: Fuzzy Clustering Based Models Applied To Petroleum Processes


Authors: Miguel Angel Ramirez Canelon, Eliezer Colina Morles

Abstract: The application of fuzzy clustering techniques has recently become in a very useful alternative in the area of modeling and identification of complex industrial processes. In particular, fuzzy clustering techniques such as Fuzzy C-Means and the Gustafson-Kessel (GK) algorithms will be analyzed and applied in details in this paper. These algorithms will be implemented in the construction of Takagi-Sugeno fuzzy models for the gas-liquid separation process, the water-oil separation process and the oil-heating process, which are important processes in the oil industry. Validations of the obtained fuzzy models will be performed and some conclusions will be established.

Keywords: Fuzzy clustering, Fuzzy C-Means, Gustafson-Kessel (GK) algorithm, least-squares method, artificial lift production methods, production separator, washing-tanks and fired heaters.

Title of the Paper: Servo Tracking of Three-Dimensional Motion by the Parallel Trinocular


Authors: Chi-Cheng Cheng, Lan-Yuan Hsu, Gwo-Long Lin, Chien-Hung Chiang

Abstract: This study develops a novel least-squares algorithm for recovering the translational motion parameters of a moving object using a parallel trinocular vision system. Although the proposed approach overcomes the matrix singularity problem inherent in binocular observers, its implementation is somewhat complex. Accordingly, a compact closed-form version of the algorithm is proposed to facilitate real-world visual imaging applications. The closed-form scheme not only resolves the matrix singularity problem, but also avoids the requirement for matrix manipulation and is therefore computationally efficient. The validity of the closed-form scheme is verified by comparing the known translation displacements of a target object with the estimated values. The results demonstrate that the proposed scheme accurately recovers the translational motion parameters provided that the movement of the target in the depth direction is of limited magnitude only. To verify the practical applicability of the proposed scheme, a servo tracking experiment is performed in which a parallel trinocular system mounted on a servo-driven positioning platform is used to track the motion of a target object as it is moved through a series of 3D displacements. The experimental results demonstrate that the closed-form scheme enables the parallel trinocular vision system to track the target effectively.

Keywords: Machine vision, Optical flow, Signal processing, Tronocular, Visual servo.

Title of the Paper: Real Time Monitoring in Web Telerobotics


Authors: Ionut Resceanu, Marius Niculescu

Abstract: There is a growing need for humans to perform complex remote operations and to extend the intelligence and experience of experts to distant applications. A blending of human intelligence, modern information technology, remote control, and intelligent autonomous systems is required. Telerobotics goes beyond autonomous control in that it blends in human intelligence and action as appropriate. It goes beyond teleoperation in that it incorporates as much autonomy as is possible or reasonable. A new approach for solving one of the fundamental problems facing teleautonomous systems is discussed: the need to overcome time delays due to telemetry and signal propagation. Optimized maintenance can reduce operating costs by demanding less resources and avoiding equipment breakdown, hence ensuring that daily manufacturing and production will not be interrupted. Web-based maintenance is one of the most efficient methods for optimizing maintenance. The Web-based monitoring system discussed provides remote sensing, monitoring, and on-line fault diagnosis for equipment, together with a collaborative maintenance platform for international experts to interactively share their experiences in maintenance.

Keywords: Telerobotics, Web, Internet, Control, TCP/IP, UDP, Real-Time, Monitoring

Title of the Paper: Advances of OPC Client Server Architectures for Maintenance Strategies - a Research and Development Area not only for Industries


Authors: Schwarz M. H, Boercsoek J.

Abstract: OPC is a matured and accepted standard in industries, but hardly used in industrial applications developed at universities, especially in Europe. Publications in this area, either using OPC-communication or developing applications have been hardly increased over the past several years. This paper reports the current state of the standard, but also describes current problems and how they can be managed and overcome. The authors also give an overview of the recently published new standard, which is called: OPC unified approach. After the fundamentals are described in this paper, the authors present their experiences with OPC to combine it with methods and procedures to develop a modern maintenance system. It also reports current developments at the Department of Computer Architecture and System Programming at the University of Kassel.

Keywords: OLE for process control, OPC, client-server architecture, condition based maintenance, unified architecture, OPC unified approach, OPC-UA

Title of the Paper: A Simple Approach to Estimate the Steady-State Performance of Self-Excited Induction Generator


Authors: K. S. Sandhu, Dheeraj Joshi

Abstract: This paper presents a new and simple model for the steady-state analysis of single and parallel operated self-excited induction generators (SEIG). In this paper an attempt has been made to incorporate the unjustified assumptions in an existing (Watson's) model. This has resulted into an improved model for the estimation of performance of SEIG. A close agreement of simulated results using proposed modeling with experimental values on test machines proves the validity and superiority of proposed model. Further proposed model is extended for the analysis of a system comprising of number of such machines operating in parallel.

Keywords: Parallel operation, steady state analysis, self-excited induction generator (SEIG), wind energy conversion.

Title of the Paper: Q-Learning Based on Hierarchical Evolutionary Mechanism


Authors: Masaya Yoshikawa, Takeshi Kihira, Hidekazu Terai

Abstract: Reinforcement learning is applied to various fields such as robotics and mechatronics control. The reinforcement learning is an efficient method to control in unknown environment. This paper discusses a new reinforcement learning algorithm which is based on Genetic Algorithm and has a hierarchical evolutionary mechanism. The proposed learning algorithm introduces new adaptive action value tables and it enables sharing knowledge among agents effectively. Regarding sharing knowledge among agents, the knowledge is inherited not only across the generations, but also in one generation. As a result, the proposed algorithm achieves effective learning, and realizes robustness learning. Computational simulations using the pong simulator which executes table tennis prove the effectiveness of the proposed algorithm.

Keywords: Q-Learning, Genetic Algorithm, Sharing knowledge among agents, Robustness of learning, Hierarchical evolutionary mechanism

Issue 4, Volume 3, April 2008

Title of the Paper: Simulation of 3D Temperature Fields of Sensors Supported by 2D IR Camera Images of Sensors' Surface Temperatures


Authors: Pavel Nevriva , Zdenek Machacek, Jan Krnavek

Abstract: In this paper, the calculation of temperature fields inside sensors' bodies is discussed. The temperature of a sensor is a function of time and spatial coordinates. Structures of mathematical models describing the temperature fields depend on the environment in which sensors operate. In this paper, temperature fields in sensors are described by the Fourier partial differential equation. Mathematical model of the particular sensor has many parameters which are known with limited accuracy. To upgrade this accuracy, the physical model incorporating both the analyzed sensor and the ambient conditions similar to the real ones is built. Mathematical model is constructed and calculated to solve tasks described by the physical model. Differences between analytical and experimental results are used for an adaptive correction of parameters of the mathematical model. In this paper, differences between models are evaluated from differences between surface temperatures of the sensors. At the physical model, sensor's surface temperature is measured by the infrared camera. At the mathematical model, sensor's temperature is obtained solving the Fourier partial differential equation by the finite element method. It is calculated by the ANSYS Workbench software. Numerical values of sensors' surface temperatures from both models can be displayed as images. To compare the experimental and analytical results, images generated by the IR camera are transformed by a set of image processing functions. Both the general method and the case study results obtained on the complex problem of the analysis of the heat transfer dynamics of the motor oil level gauge are presented.

Keywords: simulation, image processing, finite element methods, sensors.

Title of the Paper: Multiple Modeling and Fuzzy Predictive Control of A Tubular Heat Exchanger System


Authors: A. H. Mazinan, N. Sadati

Abstract: In this paper, a novel generalized predictive control (GPC) strategy using multiple models approach has been presented. The proposed strategy is realized based on the Takagi-Sugeno-Kang (TSK) fuzzy-based modeling for control of a tubular heat exchanger system. In this strategy, different operating environments of the system with varying parameters are first identified. Then for each environment, a linear model and its corresponding fuzzy predictive controller are designed. For demonstrating the effectiveness of the proposed approach, simulations are done and the results are compared with those obtained using the single model predictive control approach. The results can verify the validity of the proposed control scheme.

Keywords: Fuzzy generalized predictive control, TSK fuzzy-based modeling, multiple models control approach, tubular heat exchanger system, the best model identification, operating environments.

Title of the Paper: Impact of MOSFET's Performance on its Threshold Voltage and its Influence on Design of MOS Inverters


Authors: Milaim Zabeli, Nebi Caka, Myzafere Limani, Qamil Kabashi

: The aim of this paper is to research the impact of physical parameters which characterize the MOSFET transistors structure on the threshold voltage values and its influence on critical voltage values which characterize digital circuits that contain the MOSFET transistors. The results obtained emphasize the impact of each single physical parameter on the total value of the threshold voltage. By adjusting the values of MOSFET physical parameters the accepted threshold voltage can be achieved. Since the threshold voltage will have influence on critical voltage values which characterise MOS inverters and delay times during transfer logic states between stages, it must be taken into consideration during design phase of logic gates that contain the MOSFET transistors.

Keywords: Threshold Voltage, MOSFET Parameters, Enhancement-Type NMOS, Impurities, Doped Density, Short-Channel, Narrow-Channel, Voltage Level, Propagation Delay, Critical Values.

Title of the Paper: A Novel and Accelerated Genetic Algorithm


Authors: Huang Bao-Juan, Zhuang Jian, Yu De-Hong

: Genetic algorithm (GA) is very helpful when the developer does not have precise domain expertise, because GA possesses the ability to explore and learn from their domain. At present, the research of GA mainly focuses on the three operators and devotes to improve the algorithm efficiency and avoid premature convergence. This paper presents a cycle mutation operator and a novel selection operator; accordingly, an improved cycle mutation genetic algorithm (ICMGA) is schemed, The experimental results compared with other genetic algorithms validate the performance of this algorithm, such as the exploration ability in search space, the stabilization and calculation speed, are all superior to other algorithms, and ICMGA is not sensitive to the initial population distribution.

Keywords: Genetic algorithm, Evolution algorithm, mutation operator, selection operator, and cycle mutation operator

Title of the Paper: DSP-Based Two-Synchronized Motors Control System Using External FPGA Design


Authors: Omar Al-Ayasrah, Ayman Al-Lawama

Abstract: There are many applications that have more than one motor to be controlled dependently to execute the same task or independently to execute different tasks at the same time with high performance low cost control system. This paper presents a Two-Synchronized Motors Control System Using External FPGA Design with high performance and low cost for a variety of applications. The proposed technique is DSP and FPGA based system. An external FPGA structural design is interfaced with the PWM Generation Unit of the D SP board for the use of Two-Motor Control using one DSP Processor. The system is implemented using the Analog Devices Blackfin™ ADSP-BF561 dual core Digital Signal Processor (DSP). Core 1 is dedicated to implement the motor one control algorithm while core 2 mainly implements the motor two control algorithm with one PWM Generation Uni t to reduce the overall cost and complexity of the motors control system. The FPGA design is implemented using VHDL language and downloaded successfully to the XILINX VERTEX-E FPGA. The FPGA board is then interfaced successfully with the ADSP PWM Unit. Simulation and experimental results are achieved successfully and introduced in this paper.

Keywords: Blackfin ADSP-BF561, FPGA, Two Motors Control.

Title of the Paper: A Practical Approach for Position Control of a Robotic Manipulator Using a Radial Basis Function Network and a Simple Vision System


Authors: Bach H. Dinh, Matthew W. Dunnigan, Donald S. Reay

Abstract: This paper proposes a new practical approach using a RBFN (Radial Basis Function Network) to approximate the inverse kinematics function of a robot manipulator. It can be effectively applied for position control of a real robot-vision system in which robot movement in the workspace is observed by a camera. In fact, there are several traditional methods based on the known geometry of the manipulator to determine the relationship between the joint variable space and the world coordinate space. However, these traditional methods are impractical if the manipulator geometry cannot be determined easily, a robot-vision system for example. Therefore, a neural network with its inherent learning ability can be an effective alternative solution for the inverse kinematics problem. In this paper, an approach using a RBFN with predefined centres in the hidden layer (distributed regularly in the workspace) and a combination of the strict interpolation method and the LMS (Least Mean Square) algorithm is presented for effective learning of the inverse kinematic function. By using the strict interpolation method and constrained training data an appropriate approximation of the inverse kinematic function can be produced. However, this solution has the difficulty of how to collect the constrained training patterns whose inputs are selected at pre-defined positions in the workspace. Additionally, the LMS algorithm can incrementally update the linear output-layer weights through an on-line training process. Thus, the proposed idea of combining these techniques can produce the advantages of both methods to deal with the difficulties in practical applications, such as the sensitive structure of a real robot-vision system or a realistic situation where the initial setup and application environments are different. To verify the performance of the proposed approach, practical experiments have been performed using a Mitsubishi PA10- 6CE manipulator observed by a webcam. All application programmes, such as robot servo control, neural network, and image processing were written in C/C++ and run in a real-time robotic system. The experimental results prove that the proposed approach is effective.

Keywords: RBFN, robot-vision, strict interpolation, inverse kinematics, PA10-6CE manipulator.

Title of the Paper: A Robust Forced Dynamic Sliding Mode Minimum Energy Position Controller for Permanent Magnet Synchronous Motor Drives


Authors: Stephen J. Dodds, Gunaratnam. Sooriyakumar, Roy Perryman

Abstract: As a contribution towards improving the environment, a new position controller for vector controlled electric drives employing permanent magnet synchronous motors (PMSM) is presented that achieves approximately 27% less frictional energy loss than a conventional controller adjusted to give the same manoeuvre time for the same initial and final positions. The frictional energy loss minimisation is carried out within the constraint of a velocity-time profile of fixed form to achieve prescribed manoeuvre times for relatively large step reference position changes. Optimal settings of the parameters of the velocity-time profile are made to minimise the energy loss. The control system robustness is achieved through the use of two control techniques, forced dynamic control (FDC) and sliding mode control (SMC), which maintain the velocity-time profile regardless of the mechanical load presented to the motor. The closed loop system automatically enters a linear operational mode with prescribed dynamics as the demanded position is approached, enabling derivative feed forward pre-compensation techniques to eliminate dynamic lag if needed. Vector control is achieved by an FDC direct axis current control loop with zero reference input, assuming a non-salient PMSM. The only information required from the user is the reference position and the required manoeuvre time. For commissioning, no time consuming adjustment of PI controllers is needed in contrast to conventional vector controlled drives. Only the following parametric entries are needed: a) the motor power and voltage ratings, the permanent magnet flux, the number of pole pairs and an estimate of the total moment of inertia presented to the rotor, to calculate the maximum rotor angular acceleration magnitude for which no motor control torque saturation can occur and b) the settling time for the FDC direct axis current control. Since a specified manoeuvre time may be realised, the method is especially suited to applications in which more than one position control loop has to be coordinated. The performance of the new controller and its advantages over a conventional controller adjusted to yield the same settling time are demonstrated by simulations.

Keywords: Forced dynamic control, sliding mode control, synchronous motor drives, minimum energy manoeuvres.

Title of the Paper: The Influence of Disturbed Measured Values and Counter Pulses on Gas Volume Control


Authors: Wacker H. D., Boercsoek J.

Abstract: Firstly the authors explain the nature of contracts between primary suppliers of gas and local suppliers. They then describe and investigate an effect observed frequently in the field of gas volume and flow control. Instead of running a straight line, the volume controller opens or closes the control valve dramatically at the end of the accounting period. The effect turns out to be caused by a relative deviation of the measured value of the gas flow rate from the actual value, and it is explained by solving an easy differential equation. Rounding errors occurring during necessary calculations may lead to the same effect. In section 2 of their paper the authors introduce a more general linear differential equation to describe various kinds of perturbations simultaneously: relative and absolute deviations of the measured values from the actual values of the gas flow rate and pulses disturbing the pulses counting the standard volume flown so far. By solving the differential equation and analyzing the solution, the authors then explain the influence of the perturbations on the behaviour of the control valve. They too discuss the risk of running a peak load, i.e. of exceeding the contracted amount of gas.

Keywords: Gas Distribution System, Gas Supplier, Third Party Contract, electronic corrector systems, Standard Volume, Volume Control, Control Valve, flow rate, PID Control, Internal Set Point

Title of the Paper: Integrated Management and Optimization of the Sanitation Cycle Using Intelligent Automation Systems and Communication Networks


Authors: Marcelo De Souza, Sergio Luiz Pereira, Caio Fernando Fontana, Eduardo Mario Dias

Abstract: The recognition of the importance of our planet’s water resources by human society increased significantly during the last decade. With a growing population and environmental degradation, an efficient management of water resources is even more vital to mankind. This article introduces a new systemic proposal for an efficient management of water treatment stations and also the entire sanitation cycle. Maximizing the efficiency of water resource management, as proposed in this article, requires the development and implementation of an automation system based on intelligent systems and communication networks. Therefore, the proposal of integrated management and optimization of the sanitation cycle presented in this article is a contribution to the improvement of sustainability for human evolution.

Keywords: Automation, Management, Sanitation, Sustainability, Intelligent, Instrumentation, Communication Networks

Issue 5, Volume 3, May 2008

Title of the Paper: Design and Fuzzy Control of Hand Prosthesis or Anthropomorphic Robotic Hand


Authors: Catrina Chivu, Catalin Chivu, Catalin Georgescu

Abstract: Hand prosthesis and anthropomorphic robotic hand can be designed starting from the same mechanical structure, actuating system and control system. Thus, it is useful to have software that helps the engineers to design the optimum system. The present paper presents such software that includes one of the possible mechanical structures used both in hand prosthesis and anthropomorphic robotic hands, the actuating system and the control system. For control system was chosen the fuzzy control.

Keywords: hand prosthesis, anthropomorphic robotic hand, fuzzy control, design and simulation.

Title of the Paper: Romanian Language and Dialog systems


Authors: Catrina Chivu, Catalin Chivu, Catalin Georgescu

Abstract: The automated dialog systems are based on natural language processing, which has as main purpose the development of language computing theory using knowledge specific to informatics field, as algorithms, data structures, knowledge representation models and automat reasoning models. For many specialists in the field, speech technology includes two main subfields: vocal synthesis and speech recognition. These two subfields are complementary. The present paper presents such a system developed for Romanian language.

Keywords: speech recognition, vocal synthesis, programming, prosthetics, neural network, MBroli, SAPI

Title of the Paper: Coordination of the Authority between the Vehicle Driver and a Steering Assist Controller


Authors: Liang-Kuang Chen, Bo-Jun Shieh

Abstract: Driver steering control performance varies with time during the vehicle driving course. A serial vehicle steering assist controller is designed to provide steering correction that can compensate the difference between the current driver and an “idealized” driver model. Using variable structure model reference adaptive control, a robust adaptive controller for lane keeping assist is developed. To reduce the complexity in control computations, a simplified version of the robust adaptive steering assist controller is also developed. Due to the significant variations in human driver behaviour, the stability of the compensated system is not guaranteed and conflict between the driver and the steering assist controller exist. A model predictive control based driver model and a dual-loop structure driver model are employed to represent the variations in driver intention, and the conflict between the controller and the driver is observed from computer simulations. A simple decision making algorithm is implemented and the conflict situations are successfully avoided for different driver behaviour modes and driving scenarios. Future work of this research will focus on implementing the designed controller on a driving simulator and experiments with human drivers on the driving simulator.

Keywords: vehicle steering assist, driver interaction

Title of the Paper: Control Systems, Smart Sensors, Controller, Elements in a Control Loop, Java Card and Security


Authors: Nderim Zeqiri, Artan Luma

Abstract: An automatic control system is a preset closed-loop control system that requires no operator action. This assumes the process remains in the normal range for the control system. Elements of automatic control. Finding a transfer function for block Diagram of CNC machine-tool control system. The control system design will attempt to evaluate the system response by determining a mathematical model for the system. We have described the generalized schematic block-diagram for a closed loop, or feedback control system. Feedback loop is the signal path from the output back to the input to correct for any variation between the output levels from the set level. Programming serial and parallel port. The broad usage of Java language and Java Cards in various different fields has made them quite applicable and implementable in different applications and systems.

Keywords: Automation, Control, System, Serial port, Parallel port, Java, Security

Title of the Paper: Design and Analysis of GA based Neural/Fuzzy Optimum Adaptive Control


Authors: Jaswinder Singh, Aman Ganesh

Abstract: Process changes, such as flow disturbances and sensor noise, are common in the chemical and metallurgical industries. To maintain optimal performance, the controlling system has to adapt continuously to these changes. This is a difficult problem because the controller also has to perform well while it is adapting. The Adaptive Neural Controller (ANC) developed in this paper satisfies these goals. Using a neural network controller, ANC modifies the network parameters through Genetic Algorithms. Along with this a Fuzzy logic Controller is also implemented for the on-line tuning of PID controller even in the presence of noise. The performance of these approaches has been evaluated using data of different plants on a common set of performance indices. The simulations results show that identified GA based Adaptive neuro-controller along with PID controller was able to adapt to process changes while simultaneously avoiding hard constraints. The identified ANC balances the need to adapt with the need to preserve generalization, and constitutes a general tool for adapting neural controllers on-line. While the fuzzy system which is rather simple to build and implement (because of small computational efforts) considerably improves the system dynamics.

Keywords: Proportional-Integral-Derivative controller, Adaptive Neuro Controller, Genetic Algorithms

Title of the Paper: Possibility to Continuously Control the Tilt of Excavators with an Inclinometer


Authors: Florin Dumitru Popescu, Marin Silviu Nan

Abstract: The main problem, on which emphasis is laid, is how to maintain the stability of rotor excavators, the main machinery of a technological extracting system employed for coal mining, or any other extraction machinery, in balance. The balance survey, respectively that of the stability of these machineries is compulsory because the bearing surface is rather small compared to the other building sub-systems outside the range of the surface, onto which much higher forces operate. The lack of correct balance for the rotor excavators determines their operation in an inadequate dynamic mode, or in extreme cases, there is the danger of losing stability by tilting over the excavator respectively suffering huge material and human loss. Thus, these excavators have a mass of balance theoretically measured during the production process. It is compulsory for the correctness of the position and mass value of balance to be checked because there might be substantial error sources leading to compromise the operation. For the machineries and installations that have a small bearing surface compared to their height, an efficient control of balance can be done only if the angle of tilt of the superstructure is known, and if the angle does not exceed certain values. The limit values of the angle of tilt are determined by one condition, i.e. the composite force of both the interior and the exterior forces should pierce the plan, which is bounded by the props of the machinery. In order to continuously measure the angle of tilt of the superstructure, in any direction possible, recent studies highlight the possibility of using inclinometer to be able to control the balance and respectively the stability of rotor excavators. By measuring the angle of tilt for a structure considered rigid with the help of inclinometers, we are looking to evaluate the movement of the center of gravity toward the interior of the bearing surface, which may have consequences on the stability of the machinery. Thus a continuous control using computers over the tilt of the structure can be made considering the two perpendicular directions, so as the limit value of the angle of stability is not exceeded.

Keywords: Barycentre, Inclinometers, Data acquisitioning card, Artificial horizon, Excavator

Title of the Paper: Controls Ways of the Transportation Capacity Variation for the Canvas Conveyer


Authors: Florin Dumitru Popescu

Abstract: Mining transportation is an important element of the economic efficiency rising in mining sector, because the transportation average included in the cost of production for one tone of extracted coal, represents approximately half of it. In order to control the transportation system and to have enough information about the below-ground and the above-ground manufacturing process, it is necessary to keep a close look on the transported output through the canvas conveyer. The permanent measurement of the mining material volume controlled by continuous transporting equipment machines implies knowing its transversal section profile at a given moment and the instantaneous velocity of the transporting belt conveyor. The approximation of the material profile section is done by measuring the level of the transporting material in different points and afterwards by approximating the corresponding curve through methods of numerical interpolation. In this paper two approximation (interpolation) methods are presented: Lagrange and the spline functions method. The present study wants to solve the problem by using some unconventional methods, in order to assure reliability, precision, as well as the possibility of integrating it into the mining monitoring system. The constant measurement of the cross section of the transported material through the canvas conveyer, as well as of the belt speed, leads to the determination of the transported volume, and depending on it, knowing the average density, you can determine the output.

Keywords: Interpolation, Lagrange, Spline, Polynomial, Function, Ultrasound Transducers

Title of the Paper: New PWM Switching Technique for an Optimum Inverter Operation


Authors: Jasim. A. Ghaeb, Osama. M. Aloquili

Abstract: The main purpose of Pulse-Width –Modulation (PWM) technique in power inverters is to control the output voltage. The most familiar techniques: uniform-pulse-width-modulation and sinusoidal-pulse-width-modulation. A Small Boundary-Pulse-Width (SBPW) technique for improving the inverter performance is proposed. The new method is based on pulse-width technique. Varied pulse-widths for the middle and boundary pulses are produced, to obtain an improved inverter operation with less generation of harmonics. Simulation results show that the SBPW technique outperforms some of the traditional methods.

Keywords: Pulse-width–modulation (PWM) control, DC to AC inverters, Harmonic control, Energy conversion.

Title of the Paper: A Practical Approach to Control and Self-Localization of an Omni- Directional Mobile Robot


Authors: S. Ziaei-Rad, F. Janabi-Sharifi, M. Daneshpanah, A. Abdollahi, H. Ostadi, H. Samani

Abstract: Due to their advantages, omni-directional mobile robots have found many applications especially in robotic soccer competitions. Despite recent advances, effective control and self-localization of omni-directional mobile robots remain as important and challenging issues. In this work, a practical approach for control and self-localization of an omni-directional robot is proposed. For this purpose, a simplified model of the system is derived for fast tuning of the control system parameters. In particular, strategies for fast tuning of PID/PD coefficients for position and orientation control are devised. A vision-based self-localization and the conventional odometry systems are fused for robust self-localization. The methods have been tested in the RoboCup competition field using three Persia middle size omni-directional robots. The experimental results are shown to demonstrate the effectiveness of the proposed system and its comparison with a few other compatible approaches.

Keywords: Omni-directional, Mobile robot, Control, Self-localization.

Title of the Paper: Contact Force-Controlled SPM System Design with Fuzzy Controller


Authors: Po-Kuang Chang, Jium-Ming Lin

Abstract: This research applied both the traditional PI (Proportion and Integration) compensator and the PD (Proportion and Derivation) type fuzzy controller for a ccontact force-controlled Scanning Probe Microscope (SPM) system design. In addition, the actuator hysteresis effect was taken into consideration. It can be seen that the system performance obtained by the proposed fuzzy controller was much better, especially in eliminating the actuator hysteresis effect. This improvement has been verified by MATLAB simulation and practical implementation of a surface profiler.

Keywords: Scanning probe microscope, Force actuator, Hysteresis effect, Fuzzy controller

Title of the Paper: Mobile Satellite Antenna Tracking System Design with Intelligent Controller


Authors: Po-Kuang Chang, Jium-Ming Lin

Abstract: This research applied an intelligent controller for mobile satellite antenna tracking system design. The intelligent controller is with both the traditional PI and the fuzzy control methods. The antenna tracking and the stabilization loops were designed firstly according to the bandwidth and phase margin requirements. However, the performance would be degraded if the tacking loop gain is reduced due to parameter variation. On the other hand a PD type of fuzzy controller was also applied for tracking loop design. It can be seen that the system performance obtained by the fuzzy controller was better for low antenna tracking gain. Thus this research proposed an intelligent controller by taking both traditional PI and fuzzy controllers for antenna tracking system design with appropriate weighting factors. The results show that the performances are better, and the tracking gain parameter variation effect can be reduced.

Keywords: Antenna tracking loop, Stabilization loop, Fuzzy controller, PI compensator, Intelligent controller

Title of the Paper: Quality Evaluation Based Fuzzy Residual Modelling. Application in Hot Rolling


Authors: Salah Bouhouche, Mostefa Yahi, Benjam Hocine, Jurgen Bast

Abstract: On line quality evaluation is an important domain particularly in the complex processes where the characteristic of the product quality is difficult to measure directly. Evaluation based modelling techniques can be considered as an alternative to solve such complex problem. We consider in this work a contribution for product quality evaluation in hot rolling using fuzzy models. Residual changes are used to obtain an evaluation of product quality. Fuzzy rules are implemented in basis of the residual and first derivative changes. Application in hot rolling shows that this approach can be recommended as part of a tool of on line quality evaluation and classification.

Keywords: Fuzzy reasoning, On-line Quality Control, Quality Classification, Hot Rolling Process

Title of the Paper: Robust Control Strategy to Parameter Variations for an Interior PM Synchronous Machine


Authors: Vasile Horga, Dorin Lucache, Marcel Ratoi, Alecsandru Simion, Mihai Albu

Abstract: The interior permanent magnet (IPM) synchronous machines have several desirable features for automotive, tools machines and residential drive applications. When operating over a wide speed range, the main problem is to assure a proper and automatically set flux weakening. The paper presents a control structure of an IPM synchronous machine proper to be used also in the motoring regime, generating regime or in an integrated starter-generator regime. The control algorithm assures insensitivity to the load parameters variation. Experimental results for both cranking and generation are shown and analyzed.

Keywords: synchronous machine, interior permanent magnet, flux weakening, vector control

Title of the Paper: Reconfigurable Machine Tool Programming– A New Approach


Authors: A. Epureanu, F. B. Marin, V. Marinescu, M. Banu, I. Constantin

Abstract: This paper presents a new programming approach based on a proposed hardware and control architecture for the reconfigurable manufacturing tool machine. A new CAM is described based on virtual machining algorithm that optimizes feedrate scheduling based on geometric simulation and aims to improve the efficiency of cutting process developed using a reconfigurable machine, configured as lathe with a specific architecture. A searching procedure is proposed to find the parameter values corresponding to cutter locations along tool path during generation of the final surface.

Keywords: RMT programming, feedrate scheduling, reconfigurable machining system, numerical control, optimal control, virtual machining

Title of the Paper: Online Adaptive Learning System for Reconfigurable Machine Tool


Authors: V. Marinescu, I. C. Constantin, A. Epureanu, M. Banu, F. B. Marin

Abstract: Batch manufacturing is a widely used technique in today economy. The conceptual change of the way in which the manufacturing machines are controlled is the most important aspect in which is possible to conform with the market demands so their reconfigurability would not affect competitiveness. The problem to be solved in this paper consists in a control method development for predictive control based on prediction of the controlled variables deviation values in respect with their programmed values and also to predict the process parameters for which chatter will appear. . The basic idea is to use the data set obtained by monitoring the process during the manufacturing of the previous workpieces and during the current workpiece in order to predict the controlled variable value and to train a clasiffier algorithm. The method proposed consists in determining of the causal relation between one controlled variable and the monitored variables and then predicting its value in order to compensate the deviation from the program.

Keywords: online learning system, reconfigurable machining system, adaptive control, predictive control, error compensation, chatter, turning

Issue 6, Volume 3, June 2008

Title of the Paper: 3D Atmospheric Modeling based on MODTRAN4


Authors: Ge Li, Zhifeng Lu, Gang Guo, Kedi Huang

Abstract: All the factors of atmospheric environment that influence the transmission of infrared radiation were analyzed in detail in the paper. Taking horizontally varying atmospheric property into consideration, a 3D model of atmospheric transmission of infrared radiation is established based on MODTRAN4. Moreover, the methods of calculating the ratio of atmospheric transmission, path radiation and single scatter solar radiation are presented. This 3D model is running by using the spectral database generated by MODTRAN4. It can handle attenuation of infrared radiation through the 3D atmosphere when target is below 60km. Implementation details are also presented.

Keywords: Infrared Radiation, Model, MODTRAN4, Path Radiation, Ratio of Atmospheric Transmission, Simulation, Single Scatter Solar Radiation

Title of the Paper: Structure Design and Indirect Adaptive General Predictive Temperature Control of a Class of Passive HVAC


Authors: Tawegoum Rousseau

Abstract: This study focuses firstly on the numerical investigation of an air conditioning unit prototype developed to guarantee a microclimate with controlled temperature and relative humidity set points for crop growth chambers. Numerical techniques based on Computational Fluid Dynamics (CFD) were implemented to estimate component size and to analyze the flow characteristics of the mixed air produced by the device. Simulations disclose a non-linear relationship between the air flow rate and the aperture opening, and also show that the mixing zone was not perfect but could be improved by the addition of baffles. The promising results obtained from CFD were used to improve the automation of the device for potential application in closed greenhouses. Secondly, the indirect adaptive generalized predictive control strategy (IAGPC) with a decentralized architecture was used to control the temperature of the air conditioning unit. As the process involves time-varying, the use of a recursive estimation approach with a fixed forget factor was adopted to estimate in real time the system parameters, and to adapt simultaneously the GPC controller parameters. In order to achieve a local and global efficient performance, the proposed decentralized IAGPC architecture was applied to two principal subsystems, which compose the global unit. A significant real time experimental improvement in the system performance is observed on temperature control for a wide range of operating points.

Keywords: numerical simulation, air flow distribution, time varying parameters, decentralized control, adaptive control.

Title of the Paper: A Decision Method for Recognition in Video and Infrared Multicameras System


Authors: Cornel Barna

Abstract: This article presents an information fusion based decision method for a recognition system composed by two video cameras and two infrared cameras. First, for each of video and infrared cameras systems, geometric characteristics are obtained which in a second stage are used in three types of information fusion. The decision, for determining the label of the object captured in the images is made using a soft type rule by considering the original algorithm based on a modified Hebb-law. Comparing this result with a hard method, it can be concluded that the performance of the presented soft method overtakes the hard one.

Keywords: Uncertainty, Information fusion, Video cameras, Infrared cameras, Soft and Hard decision

Title of the Paper: Constrained Model Predictive Control Implementation for a Heavy-Duty Gas Turbine Power Plant


Authors: Hadi Ghorbani, Ali Ghaffari, Mehdi Rahnama

Abstract: In this paper, model predictive control (MPC) strategy is implemented to a GE9001E gas turbine power plant. A linear model is developed for the gas turbine using conventional mathematical models and ARX identification procedure. Also a process control model is identified for system outputs prediction. The controller is designed in order to adjust the exhaust gas temperature and the rotor speed by compressor inlet guide vane (IGV) position and fuel signals. The proposed system is simulated under load demand disturbances. It is shown that MPC controller can maintain the rotor speed and exhaust gas temperature more accurately in comprehension with both SpeedTronic™ control system and conventional PID control.

Keywords: Gas turbine, Identification, ARX, Predictive control, Power plant, Modeling, Multivariable control, PID

Title of the Paper: The Relevant Request Determination in the Public Transport System


Authors: Monica Parvan, Florian Ghionea, Cristina Flaut

Abstract: For the moment, “the relevant request determination in the public transport system” is solved using heuristic rules. This paper proves that this method, trying to simplify the maximum demanding, looses circumstances that modify essentially the results. We propose a new method for solving this issue, not using only maximum, but a combination of maximum and minimum, which, we will prove, has better results.

Keywords: Request determination in public transportation; reduction of rides requests in time; Bellman’s optimal principle; dynamic programming, linear programming.

Title of the Paper: An Epistemological Comparison between Fuzzy Logic Engines and Bayesian Filters


Authors: Claudiu Pozna, Catalin Alexandru

Abstract: In this paper we analyze two methods of artificial intelligence: the Bayesian filter and the Fuzzy Logic engine. In order to do this we present each method and compare them. The mentioned methods have similar backgrounds but from epistemological point of view they are different. The paper ends with three case studies: the first about a Fuzzy Logic engine which is integrated into a Bayesian filter, this give us the possibility to underline the mentioned difference; the second case study about a mobile robot, where we present the main advantage of the Bayesian filter, which is the possibility to compute the degree of true about the model result; and the third case study about human decision modeling with Bayesian reasoning, where we underline the flexibility of the method.

Keywords: Artificial intelligence methods, Fuzzy Logic, Plausible reasoning, Bayesian filter, Degree of true

Title of the Paper: Aspects Regarding the Object Following Control Procedure for Wheeled Mobile Robots


Authors: Adrian Korodi, Alexandru Codrean, Liviu Banita, Constantin Volosencu

Abstract: The wheeled mobile robots are representing an increasing research domain, both the hardware and the software part representing a challenge. Among the many tasks that the robots have to realize, the object following task is one of the most important ones. Almost every group of robots, which are realizing a cooperative action has to be able to accomplish this task, as well as a single robot has to be able to reach a detected object in the environment. The aim of this paper is to provide a control strategy for wheeled mobile robots realizing the object following task. Also, the paper provides a redundant solution for the robot following function in the case of multiple wheeled mobile robots, solution based on wireless communication. Infrared and sonar sensors are used to provide the inputs for the controller. The control strategy takes into consideration that the robot moves in a dynamic environment and it has to follow the target object regardless of other interfering elements.

Keywords: object following control, PID control, redundancy, wheeled mobile robots, cooperative mobile robots, sensor fault detection, fault tolerance.

Title of the Paper: The Actuators Control by Probabilistic Mathematical Modelling


Authors: Luige Vladareanu, Ion Ion, Ovidiu Sandru, Lucian M. Velea, Mihai S. Munteanu

Abstract: The paper presents a new real time control method in actuators continuous flux and their implementation using complex automations, aimed at determining the behaviour, functional parameters and performances. The mathematical model is presented for the real-time control problem of continuous flow actuators and there are indicated two probabilistic modalities which have been approached: a probabilistic evaluation and a linear prediction based procedure. The experimental results are in good agreement with the theoretically predicted results for mathematical modelling of the correlation between actuators. Finally, we obtain real-time control of actuators without the entry signals to be generated by the trial actuator by means of direct measurement. Theoretic and experimental results have shown that the behaviour errors of the actuators that have been tested through the proposed method are less than 1% while the testing duration is over 30 times less.

Keywords: actuator control, real time control,complex automations, mathematic modelling, PLCs, probabilistic evaluation, linear prediction

Title of the Paper: Digital Control Applications using TI Digital Signal Controller


Authors: Petru Dobra, Radu Duma, Daniel Moga, Mirela Trusca

Abstract: Two digital control applications are presented: velocity control of a DC motor and adaptive system identification and control of an automotive alternator. A tuning method is proposed for DC motors. Experimental application for the DC motor illustrates the effectiveness and the simplicity of the proposed method for controller design. Using adaptive system identification, an automotive alternator is identified. A regulator is implemented in order to control its output voltage. The control applications run on a Texas Instruments Digital Signal Controller. Rapid Control Prototyping is used for code generation. Once the desired functionality has been captured and simulated, using the MATLAB/Simulink/Real-Time Workshop environment can be generated code for the DSP. All task assignments to processor are automatically made by the software.

Keywords: Embedded Target, DC motor, Digital Signal Controller, Digital Control, Rapid Control Prototyping, Digital Signal Processor, Matlab/Simulink, Code Composer Studio.

Title of the Paper: From Model-Based Strategies to Intelligent Control Systems


Authors: Ioan Dumitrache

Abstract: This paper presents the evolution of control systems and trends in the field of integrated computer, communication and cognitive sciences for control applications. There have been selected and presented the most efficient control strategies used in complex process control, as well as the limitations of model-based approaches in cases that imply complex, non-linear and uncertain process models. In this context, the paper presents some trends in robust identification and design of adaptive control systems with a high level of robustness. Concepts for autonomous control of complex systems by the integration of intelligent methodologies are analyzed. Some aspects of hybrid intelligent control are considered and new directions of research towards creating a new generation of control systems are presented. The paper also includes a review of the evolution of computer controlled applications and a new paradigm - C4 - is analyzed from concept to application. Therefore, the transition from C2 to C4 paradigm is illustrated in the context of integrating computers, communication and cognition in control. Finally, advanced control techniques for manufacturing are presented, including intelligent agents, leading to large Intelligent Manufacturing Systems. Some trends in the control of complex systems are presented, including multiagent technology and hybrid systems formalism.

Keywords: model-based systems, intelligent control systems

Title of the Paper: Control-Theoretic Results on Dynamic Decision Making


Authors: S. Y. Xu, Z. P. Jiang, Y. Yang, L. Huang, D. W. Repperger

Abstract: Several approaches to learning in dynamic decision making tasks are developed in this paper on the basis of the application of feedback control theory to the case study of the Sugar Production Factory task. Previous experimental models are not robust to workload change and require a large amount of information to be stored. The control model presented here not only avoids such shortcomings, but also significantly enhances the system efficiency, adaptivity and robustness. On the other hand, as trust and self-confidence are closely linked to the capacity of automation and manual control in a supervisory control system, it behooves us to develop a dynamic model to assist the operator in gaining a better understanding of capacities. A quantitative model of trust in automation is then proposed to accurately characterize operator’s reliance on automation. Those results are demonstrated through simulation within a framework of a Sugar Factory supervisory control system.

Keywords: Control theory, Dynamic decision making, reliance on automation, Sugar Factory task, supervisory control.

Title of the Paper: Advanced Algorithms for Coupled and Inverse Problems in Electrical Engineering


Authors: Ion Carstea

Abstract: This paper presents some theoretical and numerical problems that arise in the analysis of coupled electromagnetic-thermal problems, and inverse problems in electromagnetic devices.
The principal objective of the paper is to describe some computational aspects for coupled electromagnetic and thermal fields in the context of the finite element method, with emphasis on the reduction of the computing resources. We present coupled models for magnetic field and thermal field. The mathematical model for magnetic field is based on time-harmonic Maxwell equations in vector magnetic potential formulation for axisymmetric fields. The model for the heat transfer is the heat conduction equation.
We propose simplified numerical models for coupled fields in electromagnetic devices with target examples on the induction heating devices and high-voltage and large power cables. Domain decomposition is presented in the context of the coupled fields. The analysis domain is divided into two overlapping subdomains for the two coupled-fields considering physical significance of the pseudo-boundary of the two subdomains.

Keywords: Coupled fields; Inverse problems; Finite element method.

Title of the Paper: Solutions for Nonlinear Multivariable Processes Control


Authors: Lupu Ciprian, Popescu Dumitru, Udrea Andreea, Dimon Catalin

Abstract: The paper proposes a combined feedforward and feedback control scheme with nonlinear compensators as a solution for multivariable nonlinear processes. This is developed based on classic decentralized control approach for multivariable processes. The design methods for each structure’s component are presented. These are based on experimental tests, classic identification and closed loop pole placement methods. The proposed method is compared to the classic solutions given by the decentralized and static decoupling procedures. An analysis on the advantages and the disadvantages of the proposed structure was made. To solve the disadvantages there have been proposed two additional structures. The applicability of the proposed method and of the two classic methods is proved using a real-time structure based on a RST control algorithm. In the end, its software implementation and the obtained results are also showed and commented.

Keywords: multivariable control, nonlinear process, real time system

Title of the Paper: Real-time Control Applications for Nonlinear Processes Based on Adaptive Control and the Static Characteristic


Authors: Ciprian Lupu, Dumitru Popescu, Andreea Udrea

Abstract: Nonlinear systems control is a problem of great interest and some solutions are found in the area of adaptive control. In this paper we proposes a real-time control algorithm based on a model reference adaptive control mechanism for a class of nonlinear systems. In order to obtain the reference model, an off-line procedure is used, while the controller’s parameters are determined on-line, using a static gain adaptation criterion. In order to demonstrate the relevance of this approach, several tests on nonlinear processes, using a real-time applications package developed in LabWindows/CVI were made. A solution, designed for a class of nonlinear systems, based on parametric adaptation of an RST controller is presented. Issues on the stability and robustness of the solution are also discussed.

Keywords: model reference adaptive control, adaptive law, real-time application

Title of the Paper: Classification with Diffuse or Incomplete Information


Authors: Amaury Caballero, Kang Yen, Yechang Fang

Abstract: The problem of classification has been studied by many authors, and different methods have been developed. In this paper a combination of rough sets and fuzzy logic for classification is adopted. Rough set theory helps in minimizing the number of attributes that influence the selection. Using this technique, a group of rules can be extracted. When information is diffuse and the number of obtained values for each attribute is large, so is the number of rules. Even worst is hidden information in the data that makes the process complicated. Due to this fact, an interval of values is defined for each attribute, moving from the minimum to the maximum obtained values in the database. This is what is defined as interval-valued information systems. For discriminating between solutions that may give more than one possible object due to their similarity, a fuzzy logic discrimination is proposed, which is simple, and gives accuracy not less than other methods.

Keywords: Fuzzy Logic, Rough Sets, Classification, Databases.

Issue 7, Volume 3, July 2008

Title of the Paper: A Pattern Recognition and Adaptive Approach to Quality Control


Authors: Edson Pacheco Paladini

Abstract: The present paper describes some quality control tools that develop an interactive and on-line evaluation of industrial products. These tools use pattern recognition techniques in a dynamic way, it means, they control the variations of critical characteristics of industrial products during their effective use. They also make an adaptive evaluation because considers the characteristics of each product under analysis. The tools generate a dynamic and well structured model. The operation of the model considers a set of images of the product or parts of them during some specific use or specific moment. Using a Pattern Recognition Process, the images of the product or some parts of them are captured and they are associated to some special matrices. The model then analyses the properties of these images by evaluating the properties each corresponding matrix have. This process allows determining a set of values which describe the variations the product is showing during its use. We gave so a model which develops a continuous evaluation of product quality. Thus, the model checks whether the variations of the characteristic under study are acceptable or not, considering a set of limits defined by procedures which take into consideration particularities of the product being studied. Thereto, the model itself determines which reference values are to be used to evaluate such variations. In the case of monochromatic analyses, the model seeks to define reference parameters for defect detection using maximum variation limits of gray levels on the product surface (this makes possible to detect the presence of a crack, for instance). In the case of polychromatic analyses, having established a specific property (such as intensity, saturation or chromatic hue), the model determines the most adequate values for that property. Variations complying with those parameters are considered to be acceptable. The top and bottom values of the acceptable variations can accurately define product design characteristics from the effective practical use the product is supposed to have. This paper describes the model, reports the most usual situations for its use, discusses practical cases where it was used and provides a critical evaluation of the results obtained.

Keywords: Quality control; Artificial intelligence; Pattern recognition; defect detection.

Title of the Paper: Optimal Control in Energy Conversion of Small Wind Power Systems with Permanent-magnet-synchronous-generators


Authors: C. Vlad, I. Munteanu, A. I. Bratcu, E. Ceanga

Abstract: This paper presents the results of experimental investigation of a low-power wind energy conversion system (WECS), based on a permanent-magnet synchronous generator (PMSG) connected directly to the turbine. A development system was built in order to carry out the experiments. Its detailed description is also provided. The development system can work as an autonomous system for remote sites or as a grid-connected system, illustrating the concept of distributed production of electrical energy. It includes a wind turbine simulator, which is speed or torque controlled and offers a "wind shaft", where the static and dynamic characteristics of a turbine are obtained. The wind shaft generator drives a permanent magnet synchronous generator (PMSG). The other components of the hybrid system are: a battery, a classical source and, possibly, a PV source. The hardware/software application is based on the dSPACE system. The experimental results show that the performance of a multi-polar-PMSG-based small wind power system is strongly determined by the generator’s behaviour. Two optimal regimes characteristics (ORC) are defined in this paper: the first one represents the mechanical power versus the rotational speed (ORC) and the second one is the electrical power delivered to a load versus the rotational speed (ORC). An optimal control loop aiming to maximize the delivered electrical power is designed, namely its reference is computed based on the ORC. In this way, the global efficiency of the energy conversion is maximized. The effectiveness of the proposed optimal control loop is illustrated by experimental results.

Keywords: wind system, optimal control, permanent-magnet synchronous generator, hardware-in-the-loop simulation, maximum power point tracking.

Issue 8, Volume 3, August 2008

Title of the Paper: Real-time Neuro-fuzzy Digital Filtering: Basic Concepts


Authors: J. J. Medel Juarez, J. C. Garcia Infante, J. C. Sanchez Garcia

Abstract: In this paper we describe the neural fuzzy filtering properties in real-time sense; giving an approach about the real-time neuro-fuzzy digital filters, defined in acronym form as RTNFDF. This kind of filters require the adaptive inference mechanism into the fuzzy logic structure to deduce the filter answers in order to select the best parameter values into the knowledge base (KB), actualizing the filter weights to give a good enough answers in natural linguistic sense; this require that all of the states bound into RTNFDF time limit as a real-time system, considering the Nyquist criteria. In this paper we characterize the membership functions into the knowledge base in a probabilistic way respect to the rules set decisions without lost its real-time description, performing the RTFNDF. Moreover, the paper describes in schematic sense the neurons set architecture into the filter description. The results expressed in formal sense use the concepts exposed in the papers included into the references. Finally, we present in illustrative manner the RTNFDF operations using as a tool the Matlab© software. Explicitly, the paper has eight sections conformed as follows: 1. Introduction, 2. Neural Architecture, 3. Rule Base Dynamics, 4. Neural Rules, 5. Real-time Descriptions, 6. Restrictions for RTNFDF, 7. Simulation, Conclusions and References.

Keywords: Digital filters, adaptive, neural networks, fuzzy logic, inference systems, real-time.

Title of the Paper: How Changes in Context Affect Human Behaviours and Performance in Mobile Computing Systems


Authors: Yong Jun Choi

Abstract: Many real world mobile device interactions occur in context-rich environment. Information about how users react to changes in context and perform in context-rich environments is crucial to informing strategies for mobile device design. Thus, the context of use must be considered because there are multiple tasks taking place in many mobile computing interactions. However, few empirical studies on mobile computing regarding changes in context impact users’ abilities to perform effectively are conducted to date. In this investigation, context is presumed to be a set of conditions or user states that influence the ways in which a human interacts with a mobile computing device. In order to sense and record relevant contextual factors, the investigations have been conducted to enable a device to sense characteristics of mobility, such as motion and changes in environmental conditions like lighting. The result indicates that the way in which users’ behaviour is affected by changes in context is not uniform.

Keywords: Mobile computing system, User’s contextual behavior, User’s performance, Mobile computing interaction, Mobility, Lighting

Title of the Paper: On Increased VZN Suspension Performances


Authors: Adrian-Ioan Niculescu, Dan Dumitriu

Abstract: The paper present the increased suspension performances assured by VZN shock absorbers, comparative with standard ones, based on a theoretical evaluation of the pitch behaviour and a 2D, ˝ car model simulation. The results present evolution of the front and rear body displacements, accelerations, forces in stop bumpers, piston displacement, for both VZN and standard shock absorbers. The new self-adjustable VZN shock absorber confers improved flexibility to adjust each stroke part according to the specific needs, providing a larger range of damping coefficients, function of the relative piston position in the cylinder. Both on rebound and compression, the VZN damping coefficients have low values at the beginning of the strokes, becoming medium at the middle of the strokes and high and very high to its end. So it gives a good correlation between loads and damping coefficients, decreasing body vertical acceleration and thus increasing the comfort, reducing speed at stroke ends and so the forces in stopper bumpers and thus increasing axles, body and passengers’ protection, and increasing stability at pitch.

Keywords: self-adjustable VZN, shock absorber, half-car 2D model, Matlab/Simulink, pitch, stability, comfort, body protection, axle protection, passenger protection.

Title of the Paper: On the Robustness of the Slotine-Li and the FPT/SVD-based Adaptive Controllers


Authors: J. K. Tar, I. J. Rudas, Gy. Hermann, J. F. Bito, J. A. Tenreiro Machado

Abstract: - A comparative study concerning the robustness of a novel, Fixed Point Transformations/Singular Value Decomposition (FPT/SVD)-based adaptive controller and the Slotine-Li (S&L) approach is given by numerical simulations using a three degree of freedom paradigm of typical Classical Mechanical systems, the cart + double pendulum. The effects of the imprecision of the available dynamical model, presence of dynamic friction at the axles of the drives, and the existence of external disturbance forces unknown and not modeled by the controller are considered. While the Slotine-Li approach tries to identify the parameters of the formally precise, available analytical model of the controlled system with the implicit assumption that the generalized forces are precisely known, the novel one makes do with a very rough, affine form and a formally more precise approximate model of that system, and uses temporal observations of its desired vs. realized responses. Furthermore, it does not assume the lack of unknown perturbations caused either by internal friction and/or external disturbances. Its another advantage is that it needs the execution of the SVD as a relatively time-consuming operation on a grid of a rough system-model only one time, before the commencement of the control cycle within which it works only with simple computations. The simulation examples exemplify the superiority of the FPT/SVD-based control that otherwise has the deficiency that it can get out of the region of its convergence. Therefore its design and use needs preliminary simulation investigations. However, the simulations also exemplify that its convergence can be guaranteed for various practical purposes.

Key-Words: - Fixed Point Transformation, Singular Value Decomposition, Slotine-Li Robot Control, Adaptive Control, Robustness Analysis, Complete Stability, Lyapunov Function, Sliding Mode/Variable Structure Controllers.

Title of the Paper: Structural Properties of Linear Generalized Systems


Authors: Valeriu Prepelita

Abstract: Generalized linear systems are considered, which contain in their state-space representation matrices with elements functions of bounded variation and controls in the space of regulated functions. The Perron-Stieltjes integral is used to obtain a variation-of-parameters formula. On this basis the formula of the state of the system as well as the input-output map are derived. The fundamental concepts of controllability and reachability are analyzed in this approach by means of two controllability and reachability Gramians. An optimal control is provided which solves the problem of the minimum energy transfer. The observability of these generalized systems is studied. In the case of completely observable systems a formula is obtained which recovers the initial state from the exterior data. The duality between the concepts of controllability and observability is emphasized as well as Kalman’s canonical form.

Key–Words:  functions of bounded variation; regulated functions; linear systems; controllability;  observability; weighting patterns.

Title of the Paper: Application of Fuzzy Logic Controller for Intensive Insulin Therapy in Type 1 Diabetic Mellitus Patients by Subcutaneous Route


Authors: Laleh Kardar, Ali Fallah, Shahriar Gharibzadeh, Fatollah Moztarzadeh

Abstract: - The work we describe here is aimed at assisting out-patients affected by insulin dependent diabetes mellitus with an advisory/control algorithm. This advisory/control algorithm incorporates expert knowledge about the treatment of this disease by using Mamdani type fuzzy logic controllers to regulate the blood glucose level (BGL) when the diabetic patient is subjected to a glucose meal disturbance or fluctuations in the measured glucose level due to error in the measuring instrument. We proposed two-level architecture for control system. The goal of the Low Level Module is to suggest the next insulin dosage of both short and intermediate acting insulin (Regular and NPH) formulation that are programmed in a three-shot daily basis before meals, depending on the blood glucose measurement. The combined preparation is then injected by the patient through a subcutaneous route. The High Level Module adjusts the maximum amounts of insulin provided to the patient in a time-scale of days. This module aims to work as a supervisor of the low level module. Simulations are illustrated, using a flow-limited model for diabetes mellitus based on the work of Puckett.

Key-Words: - Diabetes mellitus, Fuzzy logic controller, Intensive insulin therapy

Title of the Paper: The Implementation of Clean Production and the use of Neural Networks in Forecasting Waste Management


Authors:  Aleriu Lupu, Catalin Lupu, Nicolae Morariu

Abstract: In this article we present: - the implementation of "clean production" which means production based on careful evaluation of the product since its design phase to ensure that both the product and processes related to it at all stages of its life cycle (ranging the extraction of raw materials, manufacturing, packaging, consumer / use, waste collection and treatment) promotes the interests of the community, in particular as regards the environment. Clean production has four main elements: - Caution, which involves taking measures insurers even in the case of yet unconfirmed suspicions concerning a potential novitiate to human health or the environment;

- Prevention, as expression of conscience that is cheaper and more efficient to prevent environmental degradation than to provide remedies;
- Democratic participation in decision-making of all stakeholders
- An integrated and holistic approach.

a new concept taking in consideration the sweepings administration and which consist

in: 1. the employment of neuronal network for predict serial time representing sweepings amount which are collected from population in time. The problems of prediction the serial time can be associated with neuronal network call “feed-forward”. Number of entrances unities are equal than number of emergences unities. The number of emergences unities represents the target of prediction. The prediction “one step before” can be realized with an emergences unities network, and the prediction with “K steps before” can be associate to a network with K emergences unities. Examples: 1. A model of a neuronal network “one step before”, which use six terms of serial time to predict the next term of series ( 6 neurons at entrance, 15 in hide tier and one in emergence tier, entering ==(xt-1, xt-2, xt-3, xt-4, xt-5, xt-6, ), emergence = xt ); 2. A model of a neuronal network in to 8 terms of serial time are using for predict the next 2 terms; 3. A model of neuronal network in to 6+2(t-1) terms of serial time are using for predict the next “t” terms. - the employment of a new index BPL for the prognosis of sweepings administration consulting of: 1. population (the index of variety of population); 2.“the habitat” of sanitation services; 3. economic development: - the economic development with α% / year represents an increase of assimilated sweepings amount emanated from shop keeping (Pce – the economic development percent ); - the grows with β% / year of purchase represent an increase of sweepings (Pv – the purchase grows percent) 4. the amount of sweepings collected from population and economics agents; 5. the amount of sweeping from gardens, plaza and streets; 6. the amount of mud from service station, from buildings and knockings. For prognosis of sweepings administration development for a certain region and for a certain period of time, are used the scripts. For certain period are constituted the purposes and aims for short , medium and long time. Each script must have the same base which includes the historical evolution of generation system of sweepings for a period between 5 and 7 years. Inside of scripts are constituted the alternatives. Each alternative describe an integrated system of management of sweepings which includes the available and practical operating method of recycle, treatment and elimination of sweepings. The main criterions of selection for the best script have to accomplish the principles of permanent development: - to have minimal negative effects about environment; to be permissible in socially; - to be doable in economically.

Key-Words: neural network, sweeping administration, prognosis, economic development, serial time.

Title of the Paper: Product Definition in Virtual Space Using Background information at Description of Engineering Objects


Authors: Aszlo Horvath, Imre J. Rudas

Abstract: - Current technology of engineering has reached a level where lifecycle product information, comprehensive sets of model creation procedures, product data management, and Internet based communication environment serve integrated group work of engineers. It is inevitable, that the next main phase of development of the digital product definition is enriching content of product model in order to more intelligent decision support at product development. In this paper, the authors introduce a new methodology as a contribution to future intelligent modeling systems. Paper starts with a discussion on possibilities of enhanced product definition as a result of extension of current professional industrial modeling systems. Following this, a method is given for the description of associative features in product model. Next, description of associative features, extension of modeling by background content, as well as extension of product model for content constitute the main sections of the paper.

Key-Words: - lifecycle management of product information, product modeling, handling changes at product development, human – computer interaction in engineering, information content in product model.

Title of the Paper: Graphic Simulator for the Visual Control of Hyperredundant Robots


Authors: Dorian Cojocaru, Razvan Tudor Tanasie

Abstract: - Tentacle manipulators produce changes of configuration using a continuous backbone made of actions which bend. In this paper, a new project for controlling a continuum robot is presented. The robotic structure uses cables to transmit forces to the elements of the arm. This new robot is actuated by stepper motors. Due to the difficulties of using distributed sensors along the manipulator structures, it was decided to se a vision system. The vision system is composed by two pan / tilt / zoom cameras and a frame grabber. A graphical simulator was designed and implemented in order to test the robot behavior under certain circumstances. The camera calibration using this graphic simulator is also presented. The term of “camera calibration” in the context of this paper refers to positioning and orienting the two cameras at imposed values.

Key-Words: - Hyper redundant robots, Visual Control, Graphic Simulator

Title of the Paper: Robot Pose Estimation by Means of a Stereo Vision System


Authors: J. Sogorb, O. Reinoso, A. Gil, L. Paya

Abstract: Mobile robots are characterized by their capacity to move autonomously in an environment that is ether known or unknown or only partially known. Their uses and applications are wide and are incorporate  into a great many fields including underground and submarine work, space missions, security systems, military applications, and many more. It is for this reason that that a mobile robot is rarely fitted with only one sensor to carry out all of its multiple tasks, being much more frequent the use of various sensors combined within the system that complement one another to complete their different functions. In this way it is possible to find robots where estimation of position1 and the updating of the map is carried out by video cameras or laser scanners, while obstacle detection is achieved using sonar. In this respect it is important to highlight the close relationship that exists between the problem of position estimation and that of the construction of a map of the surroundings, with exact localization of the robot necessary to be able to carry out map construction and vice versa. In this work we focus solely on the problem of localization, comparing different estimation algorithms of the trajectory taken by a robot from the observations and readings obtained by the robot itself. In our problem, we will work with images taken by a stereoscopic vision system of uncalibrated cameras, we will assume that the movement of the robot is on a flat surface and we will use natural landmarks. As we will see, the information obtained from this type of sensor allows a robust estimation of movement taken between each pair of observations without the need to use the information from the robot’s propioceptive sensors. The solution of this problem, known as visual odometry, is critical within the majority of subsequent navigation processes.

Key-Words: Visual odometry, mobile robot, stereo vision, position estimation, natural features.

Title of the Paper: Design and Implementation of Portable Data Acquisition Unit in Process Control and Supervision Applications


Authors:  Petr Dostalek, Vladimir Vasek, Jan Dolinay

Abstract: Paper deals with design and implementation of portable data acquisition unit based on 8-bit microcontroller Free scale 68HC908GP32 in process control and supervision applications. Its hardware design is adopted to fulfill high reliability and immunity against industrial environment, high precision and compact dimensions. Communication with supervision system is performed via standard RS232 interface utilizing universal ASCII-based communication protocol which is supported by number of software environments. In order to improve development of new software applications with this device a support program libraries for Visual C++, Control Web and Matlab/Simulink was created. Correct function of the data acquisition device and support software libraries were tested on educational model of heating plant with time delay in Mat lab 6.5 and Control Web environments.

Key-Words: Data acquisition, process control, Control Web, Matlab, program libraries, 68HC908GP32.

Title of the Paper: Optimal Reorganization of Agent Formations


Authors:   Dalila B. M. M. Fontes, Fernando A. C. C. Fontes

Abstract: In this article we address the problem of determining how a structured formation of autonomous undistinguishable agents can be reorganized into another, eventually non-rigid, formation based on changes in the environment, perhaps unforeseeable. The methodology can also be used to correctly position the agents into a particular formation from an initial set of random locations. Given the information on the agents current location and the final locations, there are n! possible permutations for the n agents. Among these, we seek one that minimizes a total relative measure, e.g. distance traveled by the agents during the switching. We propose a dynamic programming methodology to solve this problem to optimality. Possible applications can be found in surveillance, damage assessment, chemical or biological monitoring, among others, where the switching to another formation, not necessarily predefined, may be required due to changes in the environment.

Key–Words: Combinatorial optimization, dynamic programming, formation reorganization.

Title of the Paper: Modernization of Control System for Enzymatic Hydrolysis


Authors:   J. Dolinay, P. Dostalek, V. Vasek, K. Kolomaznik, D. Janacova

Abstract: - This paper describes new computer system for measurement and control for laboratory system for recycling chromium from tannery waste. The system is used for research and verification of unique chromium-recycling technology based on enzymatic hydrolysis developed at our institute. As the original control equipment became outdated, it was necessary to rebuild the technology with modern means of automatic control. This paper introduces the whole system for chromium recycling with focus on the control structure of the most important parts of the technology. The development and implementation of a new computer control system is described, from choosing the devices to final activation.

Key-Words: - Tannery waste, Chromium, Advantest, Control Web, Saia, Hydrolysis.

Title of the Paper: Control of Electrical Drives Based on Fuzzy Logic


Authors: Constantin Volosencu

Abstract: - The paper presents the theory of control systems for electrical drives based on fuzzy logic, from the author’s point of view. The paper offers practical answers at questions related to the design of speed control systems based on fuzzy PI speed controller: what is the adequate structure of fuzzy controller, the number of rules fuzzy values, how to assure stability, implementation, control system quality criteria. The conventional design method for the linear speed control systems is presented as a comparison base. An example of fuzzy control systems for d.c. drives is given, with its modeling, simulation, design, transient characteristics and quality criteria.

Key-Words: - control systems, fuzzy logic, electrical drives, stability analysis.

Title of the Paper: A Telematics Approach to Documentation on Railways


Authors:   Jon Mikel Rubina Diez, Gerardo Aranguren Aramendia, Inigo Odriozola Lertsundi

Abstract: - Nowadays locomotive engineers yet have to carry printed documentation in a big and heavy bag. This situation involves poor accessibility and inadequate management of this information that hinder railway operations. A new telematics solution is proposed to address the problems derived from carrying this huge amount of printed paper. The solution is analyzed functionally, explaining its characteristics and outlining some technical aspects of its implementation. This thesis is inspired on a case study deployed at Euskotren, a railway operator in the Basque Country. During the experiments that were carried out, this innovative approach to documentation has proved to improve the efficiency of railway operations and in turn improve safety in railway operations.

Key-Words: - railway telematics library software HMI train documentation

Issue 9, Volume 3, September 2008

Title of the Paper: A Mathematical Model for Control of an Autonomous Vehicle Convoy


Authors: Plamen Petrov

Abstract: This paper describes the modeling of a two-vehicle convoy and the design of a vehicle following controller that tracks the trajectory of the vehicle ahead with prescribed inter-vehicle distance. Kinematic equations of the system are formulated applying standard robotic methodology. We consider autonomous vehicle following without any information obtained from road infrastructure or communicated from the lead vehicle. Assuming that the leader linear and angular velocities, as well the curvature radius of the path traveled by the lead vehicle, are unknown constant parameters, an adaptive tracking controller is proposed. With only the current inter-vehicle relative position and orientation available for feedback control, the control velocities of the following vehicle are computed using the leader velocity estimates obtained from the dynamic (adaptive) part of the proposed controller. For constant velocity maneuvers of the leader, at steady state, the two-vehicle convoy will travel concentric arcs of same radii with prescribed inter-vehicle spacing. For time-varying lead vehicle velocities, the proposed controller achieves ultimate boundness of the closed-loop system in error coordinate. Various simulation results demonstrating the performance of the controller are included.

Keywords: Autonomous vehicle convoy, vehicle following, kinematic model, nonlinear adaptive control

Title of the Paper: Interactive Pareto Optimal with Advantage and Application in Distribution Planning


Authors: Cheng-Chien Kuo, Po-Hung Chen

Abstract: An interactive pareto optimal with advantage (IPOA) approach for bi-objective programming is proposed and applied on capacitor placement and sizing problem. Two main contradictory concerned which including cost and quality properties are considered as bi-objective programming formulation. The IPOA approach can provide a valuable trade-off pareto-optimal solution by following the intention of decision makers (DMs). Many nonlinear characteristics of distribution feeders, and their load, operating and expansion constraints could be all considered for practical operation. Also, both fixed and switched types of capacitors are included. The effectiveness and feasibility of the proposed approach were demonstrated by an actual feeder study systematically with particle swarm optimization method. The experiment showed encouraging results, suggesting that the proposed approach was capable of efficiently determining higher quality solutions about distribution planning problem.

Keywords: Interactive pareto optimal with advantage, Capacitor placement and sizing, Particle swarm optimization, Distribution planning, Bi-objective programming

Title of the Paper: Hydraulically Actuated Active Suspension System with Proportional Integral Sliding Mode Control


Authors: Y. M. Sam, N. M. Suaib, J. H. S. Osman

Abstract: This paper will present a new mathematical model and control of the hydraulically actuated suspension system for the half model. The model presented takes into account all the pressure difference parameters inherent in the hydraulic cylinder. However, from the derived mathematical expression for the systems, it is found that the system may experience a mismatched condition problem due to the nature of the road disturbance which is not in phase with the control input. In order to achieve the desired ride comfort and road handling and to solve the mismatched condition, a proportional-integral sliding mode control (PISMC) technique is presented to deal with the system and uncertainties. Extensive simulations are performed for different road profiles and the results showed that the proposed controller performed well in improving the ride comfort and road handling for the half car model using the hydraulically actuated suspension system. It is shown that the proposed controller is capable to overcome the mismatched condition problem that present in the active suspension system. Furthermore, the results also showed that the system is completely insensitive to the external disturbance due to the road surface irregularities.

Keywords: Active Suspension System, Hydraulic Actuator, Sliding Mode Control

Issue 10, Volume 3, October 2008

Title of the Paper: Modeling, Simulation and Optimal Control for an Aircraft of Aileron-less Folding Wing


Authors: Zheng Jiewang, Shijun Guo, Wei Li

Abstract: The purpose of this paper is to discuss the method of modeling and control system design for a loitering aircraft of aileron-less folding wing. A nonlinear model of the aircraft was established, and then linearized by small disturbance method. The lateral-directional stability augmentation options were analyzed through the root locus plots. The pole placement method based on linear quadratic regulator (LQR) technology was used to achieve desirable dynamic characteristics. In the analysis, the state parameters which represent rapid oscillation states of the aircraft such as roll rate and yaw rate were set as primary control parameters in the inner loop. The states oscillated slowly such as rolling angle and yaw angle were set as main control parameters in the outer loop. Based on the self-organizing fuzzy control algorithm, the aircraft can be controlled to fly in a desired path. Two types of course control plan were investigated and verified. The results show that the control plans are feasible and the control system is adequately robust to meet the requirements of the course control.

Keywords: Loitering aircraft, pole placement, LQR, fuzzy control, bank-to-turn (BTT), skid-to-turn (STT)

Title of the Paper: Stabilization of Fuzzy Control Systems


Authors: Constantin Volosencu

Abstract: The paper presents the way to use Lyapunov techniques to analyse and to assure stability of control systems with fuzzy PI controllers. The stability is assured based on a compensation of the input-output characteristic of the fuzzy blocks used in PI fuzzy controller. The compensation is made on fuzzy control law by the action in parallel of a crisp block for non-linear parts of input saturations. Stability analysis of fuzzy control systems for general processes is framed in the field of non-linear systems. The paper presents the way to prove absolute global internal stability in general cases. The correction principle is theoretically substantiated and methodologically structured with application at the fuzzy control of the second order processes.

Keywords: Fuzzy control systems, Lyapunov techniques, circle criterion, absolute internal stability, nonlinear systems.

Title of the Paper: An Optimal T-S Model for the Estimation and Identification of Nonlinear Functions


Authors: Agustin Jimenez, Basil M. Al-Hadithi, Fernando Matia

Abstract: A novel optimal method is developed to improve the identification and estimation of Takagi-Sugeno (TS) fuzzy model. The idea comes from the fact that the main drawback of T-S model is that it can not be applied when the membership functions are overlapped by pairs. This limits the application of the T-S model because this type of membership function has been widely used in the stability and controller design of fuzzy systems. It is also very popular in industrial control applications. The method presented here can be considered as a generalized version of T-S fuzzy model with optimized performance in approximating nonlinear functions. Various examples are chosen to show the high function approximation accuracy and fast convergence obtained by applying the proposed method in approximating nonlinear systems locally and globally in comparison with the original T-S model.

Keywords: Nonlinear systems, Fuzzy systems, Takagi-Sugeno fuzzy model, Universal approximators, optimization

Issue 11, Volume 3, November 2008

Title of the Paper: Additive Faults Detection and Level Control in Coupled Tanks


Authors: Canureci Gabriela, Vinatoru Matei, Maican Camelia, Iancu Eugen

Abstract: This paper presents a strategy for level control, detection and localization of the possible faults types for coupled tanks. The control and faults detection algorithm was developed using the combination of Matlab - Simulink with WinCon 5.1 software. Also in the paper, a mathematical model of the process is developed used design and control algorithm. The experimental applications were developed on the didactical plant ”Quanser Water Level Control Two Tank Module”.

Keywords: Detection, localisation, additive faults, disturbances, noise, level control, pole placement

Title of the Paper: Control System Simulator for Steam Boiler Parameters


Authors: Camelia Maican, Matei Vinatoru, Gabriela Canureci, Eugen Iancu

Abstract: The paper presents the research results related to control of the steam boiler parameters: drum level, furnace pressure and steam pressure. It was developed the mathematical model of the water-steam system and furnace part of the boiler. Also, the paper presents the algorithm for real time detection of model parameter variations. In this context a correction method, validate through simulation was developed.

Keywords: Steam boiler, steam pressure, furnace pressure

Title of the Paper: Balance Control by Weighting and Tensiometric Measurements of Bucket Wheel Excavators


Authors: Marin Silviu Nan, Iosif Kovacs, Florin Dumitru Popescu

Abstract: An essential element when establishing the balance of a bucket wheel excavator is the determination of the barycentre, the best results being thus obtained by weighting after having installed all the components. The problem, on which emphasis is laid, is how to maintain the stability and equilibrium of bucket wheel excavators or any other extraction machinery during operation, the main machinery of a technological extracting system employed for coal mining. The balance survey, respectively that of the stability of these machineries is compulsory because the bearing surface is rather small compared to the other building sub-systems outside the range of the surface, onto which much higher forces operate. The lack of correct balance for bucket wheel excavators determines their operation in an inadequate dynamic mode, or in extreme cases, there is the danger of losing stability by tilting over the excavator respectively suffering huge material and human loss. It is compulsory to verify for the correctness of the position and mass value of balance because there might be substantial error sources leading to compromise the operation. One of the most popular methods is that of weighting the entire equipment from the superior platform of the excavator. The weighting process implies the lifting of the excavators in three spots with hydraulic cylinders, the measurement of the forces, as well as the measurement of pressure inside the cylinders and of the stroke of each cylinder. The data measurement and rehashing installation is destined to determine the dimensions that finally define the weighting process of excavators or other operating machineries to which the balancing and control of stability is imposed. Thus, two types of data measurement and rehashing installations depending on the nature and type of the transducer used will be presented. For the first type, only analogical signals are transmitted to a numerical computer, and for the second type only digital signals are transmitted.

Keywords: Barycentre, Tensiometric bridge, Excavator, Force Transducer, Pressure Transducer

Title of the Paper: Fuzzy Programming Problem in the Weakly Structurable Dynamic System and Choice of Decisions


Authors: Gia Sirbiladze, Anna Sikharulidze, Natia Sirbiladze

Abstract: This work deals with the problems of the Weakly Structurable Continuous Dynamic System (WSCDS) optimal control and briefly discuss the results developed by G. Sirbiladze [17]. Sufficient and necessary conditions are presented for the existence of an extremal fuzzy optimal control processes, for which we use R. Bellman’s optimality principle and take into consideration the gain-loss fuzzy process. A separate consideration is given to the case where an extremal fuzzy control process acting on the WSCDS (1) depends and (2) does not depend on an WSCDS state.
Applying Bellman’s optimality principle and assuming that the gain-loss process exists for the WSCDS, a variant of the fuzzy integral representation of an optimal control is given for the WSCDS. This variant employs the instrument of extended extremal fuzzy composition measures constructed in [16].
The questions of defining a fuzzy gain relation for the WSCDS are considered, taking into account the available expert knowledge on the WSCDS subject-matter.
An example of constructing of the WSCDS optimal control is presented.

Keywords: Fuzzy Optimal Control, Fuzzy Dynamic Systems, WSCDS, Extended Extremal Fuzzy Measures, Sugeno Type Extremal Integrals, Fuzzy Gain-Loss Process, Bellman’s Optimality Principle

Title of the Paper: A Decision Support System for Safe Switching Control - Design and Implementation


Authors: F. N. Koumboulis, M. P. Tzamtzi, M. G. Skarpetis

Abstract: In the present work a Decision Support System (DSS) is described, that supports decision making with regard to the selection of the appropriate control design approach for nonlinear plants. More specifically, this DSS supports decision making concerning several aspects of designing safe switching controllers. Decisions are based on specific available information about the plant’s description and characteristics, as well as the available experimental data. The implementation of this DSS using MATLAB is also presented.

Keywords: Decision Support System, Safe Switching, Nonlinear Control Systems

Title of the Paper: Analytic Modeling and Metaheuristic PID Control of a Neutral Time Delay Test Case Central Heating System


Authors: Fotis N. Koumboulis, Nikolaos D. Kouvakas, Paraskevas N. Paraskevopoulos

Abstract: In the present paper, the analytic mathematical model of a test case central heating system is developed in the form of a nonlinear neutral time delay model with time varying delay which in turn is simplified to a neutral time delay model with constant time delay. In the process it is shown that the influence of the delay is significant, thus its incorporation to the model is of high importance while the constant delay approximation imposes only small error. A PID controller is derived to control the temperature of a room, which is modeled as a first order differential equation. The controller parameters are evaluated using a metaheuristic algorithm.

Keywords: Central heating, modeling, neutral time delay system, PID controller, metaheuristic

Issue 12, Volume 3, December 2008

Title of the Paper: Output Feedback Model Predictive Control for Nonlinear Systems


Authors: I. I. Siller-Alcala, J. Jaimes-Ponce, R. Alcantara-Ramirez

Abstract: In this paper, an Output Feedback Model Predictive Control for nonlinear systems is presented. The proposed output feedback control consists of the well known robust controller NCGPC (Nonlinear Continuous Time Generalized Predictive Control) and an open loop observer (a simulated model in parallel) in order to estimate the output derivatives and a regulation filter used to account for plant/model mismatch. The main advantages of the new approach are i) that the assumption of full-state feedback inherent in feedback linearization schemes is eliminated, the only measurement required is the output and finally ii) the process output converges to a constant reference in spite of presence of parameter uncertainties and process disturbances. The analysis of the induction motor and simulation results in the numerical example show that the output feedback model predictive control proposed can tolerate certain process uncertainty.

Keywords: Nonlinear Control, Predictive Control, Output Feedback Control, Internal Model Control, Robust Control

Title of the Paper: Application of Genetic Algorithms and Visual Simulation in a Real-Case Production Optimization


Authors: Davorin Kofjac, Miroljub Kljajic

Abstract: This paper presents a real case customized flexible furniture production optimization. Such a make-to-order production must be flexible to meet the customer’s needs, which are changing frequently. Hence, a frequent review of the production process is needed to ensure near-optimal production schedule to meet the minimal makespan constraint. In such a case we are confronted with a tradeoff between makespan and optimization runtime to ensure efficient realtime scheduling. The genetic algorithm production scheduling optimization is presented to solve a job shop scheduling problem with recirculation. Several initial population generators, selection methods, and crossover and mutation methods are discussed and tested. The visual model of the furniture production process was developed during the research. Such a model is closer to end-user perception and is used to clarify the results of numerical optimization. It also enables the implementation of end-user’s expert knowledge into the optimizer to reduce the GA search space with a goal of reducing the runtime to a minimum.

Keywords: Production scheduling, Job-shop, Recirculation, Genetic algorithms, Simulation, Optimization

Title of the Paper: Control of a Differentially Driven Mobile Robot Using Radial Basis Function Based Neural Networks


Authors: Gokhan Bayar, E. Ilhan Konukseven, A. Bugra Koku

Abstract: This paper proposes the use of radial basis function neural networks approach to the solution of a mobile robot orientation adjustment using reinforcement learning. In order to control the orientation of the mobile robot, a neural network control system has been constructed and implemented. Neural controller has been charged to enhance the control system by adding some degrees of award. Making use of the potential of neural networks to learn the relationships, the desired reference orientation and the error position of the mobile robot are used in training. The radial basis function based neural networks have been trained via reinforcement learning. The performance of the proposed controller and learning system has been evaluated by using a mobile robot that consists of a two driving wheels mounted on the same axis, and a free wheel on the front for balance.

Keywords: Mobile robot, control, neural networks, radial basis function, learning, trajectory

Title of the Paper: Thermal Sprayed Coatings Adherence – Influencing Parameters


Authors: Mihaiela Iliescu, Emil Turdeanu

Abstract: Thermal spraying represents the process of obtaining new special multilayer structure materials, with good mechanical and chemical characteristics. These materials are often used in solving real important problems, like repairing worn parts working under severe wearing conditions or, ensuring efficient corrosion protection of parts used in sea, as platform, bridges, or obtaining high refractory surfaces. Most of the times, once obtained, these coatings need additional machining and, it is of interest to study how, and, if, any of the machining parameters do influence one of their very important characteristic, meaning, adherence to the basic substrate. The paper presents a study on the adherence of thermal sprayed coatings, obtained from some Romanian thermal sprayed materials and submitted to exterior cylindrical turning.

Keywords: Thermal spraying, multilayer coatings, cylindrical turning, adherence, transducer, sample

Title of the Paper: A Study of the Observability of Multidimensional Hybrid Linear Systems


Authors: Valeriu Prepelita

Abstract: A class of multidimensional hybrid linear systems is presented, with the time vector composed by q continuous-time real components and by r discrete-time integer ones, q; r ? 1. The state equation is of multidimensional partial differential-difference type. A generalized variation-of-parameters formula is provided and it is used to obtain the state and the general response of the system. The fundamental concept of observability is studied for these systems. An observability Gramian is introduced, which is a generalization of the Gramians corresponding to the classical 1D continuous-time and 1D discrete-time systems.
In the case of completely observable systems this Gramian is used to obtain a formula which provides the initial state of the system for any input-output pair. A list of observability criteria is given for time-invariant systems and the duality between the concepts of observability and reachability is emphasized.

Keywords: Multidimensional hybrid systems, observability, observability Gramian, time-varying systems, timeinvariant systems

Title of the Paper: Water Flows' Management System at the Secondary Cooling in the Continuous Steel Casting Process


Authors: Corina Daniela Cuntan, Ioan Baciu

Abstract: In this work it was proposed the structure of a management system for the water flows in the secondary cooling area within the continuous steel casting process.
The management system assumes the utilization of some temperature and speed transducers, of which output measures represent the input variables for the Fuzzy regulator. For adapting the output measures from transducers with the inputs of the Fuzzy regulator, it was conceived an adaption system that achieves the variation range 1-100%.
For implementing the expert system, it was achieved a base of specific knowledge, introduced by the human expert and materialized as some sets of rules that constitute the reasoned judgement based on which the system is acting by analyzing the variables’ real values.

Keywords: Translation circuit, continuous casting, water flow, secondary cooling, Fuzzy controller

Title of the Paper: Object Oriented Modelling of Variable Envelope Properties in Buildings


Authors: Borut Zupancic, Anton Sodja

Abstract: The paper deals with some important aspects of continuous systems modelling approaches. Namely the traditional approach is based on block oriented schemes in which causal relations play an important role. However this causality is artificially generated in order to fulfil appropriate conditions for simulation on conventional sequential computers. Fortunately new concepts which are based on object oriented approaches, physically oriented connections and algebraic manipulations enable the so called acausal modelling. Both approaches are used in the modelling of thermal flows in intelligent building. Advantages and disadvantages of two concepts and environments are discussed. As validation is always the most important phase of each modelling project a small physical “chamber” was built. The second part of the paper demonstrates the efficiency of the developed simulation model. With the simulation we studied how to compensate or efficiently use variable outdoor conditions, e.g. solar radiation and outdoor temperature in order to assure the appropriate indoor conditions. This was not performed with conventional approaches, e.g. with heating, cooling, ventilating, humidifying, etc. but with on line dynamical adaptations in the building envelope. Variable wall insulation, movable window insulation, movable shading system and rotating object were proposed and studied.

Keywords: Object oriented modelling, Simulation, Acausal modelling, Thermal flows, Intelligent building

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