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Ant Colony Based Model Prediction of a Twin Rotor system

Procedia engineering 2012年 41卷 1135-1144页

作者： S.F. Toha S. Julai M.O. Tokhi Department of Mechatronics Faculty of Engineering International Islamic University Malaysia Malaysia Department of Mechanical Faculty of Engineering University Malaya Malaysia Department of Automatic Control Systems and Engineering University of Sheffield UK

Interest in biologically-inspired optimization techniques has increased due to its accurate results, fast performance and ease of use. In this paper, an ant colony optimization (ACO) technique is deployed and used for modelling a twin rotor system. The system is perceived as a challenging engineering problem due to its strong cross coupling between horizontal and vertical axes and inaccessibility of some of its states and outputs for measurements. Accurate modelling of the system is thus required so as to achieve satisfactory control objectives. It is demonstrated that ACO can be effectively used for modelling the system with highly accurate results. The accuracy of the modelling results is demonstrated through validation tests including training and test validation and correlation tests.

关键词： Ant colony optimisation Parametric modelling Twin rotor system Auto Regressive model

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Reducing off-road vehicle seat vibrations using hydraulic piston and fuzzy logic controller

Reducing off-road vehicle seat vibrations using hydraulic pi...

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International Symposium on Electronics in Marine (ELMAR)

作者： Almir Salihbegović Emir Sokić Aida Salihbegović Mujo Hebibović Department for Automatic Control and Electronics Faculty of Electrical Engineering University of Sarajevo Sarajevo Bosnia and Herzegovina

This paper examines the capabilities of fuzzy logic based controllers in the process of active suspension of a heavy vehicle seat vibrations. The hydraulic cylinder is used as an active element, while the damper and the air spring are used as passive elements for reducing vibrations. MATLAB and Simulink are used as tools for developing the simulation model of the driver seat. The mathematical model was created according to the physical setup of the vehicle seat at the testing laboratory. Description of the seat, including its mechanical characteristics and mathematical model, is given in the paper. control system description and implementation on the experimental setup using dSPACE module, is also explained. The SEAT value is used for the validation of control quality. The obtained simulations show that the developed suspension controllers provide superior passenger comfort for different types of road.

关键词： Vibrations Vehicles Mathematical model Acceleration Force Suspensions Roads

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The effect of functional electrical stimulation (FES) on paraplegic muscle fatigue

The effect of functional electrical stimulation (FES) on par...

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International Colloquium on Signal Processing & Its Applications, CSPA

作者： R. Jailani M. O. Tokhi Faculty of Electrical Engineering Universiti Teknologi MARA Shah Alam Selangor Darul Ehsan Malaysia Department of Automatic Control and System Engineering University of Sheffield UK

Stimulation trains of different combination of frequency and pulse-width can be used to generate the muscle force required to perform a functional task during functional electrical stimulation (FES). However, with repetitive activation, the muscle will fatigue and an increase in either the frequency or the pulse-width of stimulation will be required to enable the targeted muscle force to be maintained. This study compares isometric performance and paraplegic muscle fatigue using two different protocols: protocol 1 uses 5 different stimulation frequencies varying from 10Hz to 50Hz with other parameters fixed; and protocol 2 uses 5 different stimulation pulse-widths varying from 200μs to 400μs with other parameters fixed. This range is selected based on a suitable frequency and a pulse width for paraplegic. Muscle performance is assessed by measuring percent decline in peak force and maximum muscle force for different stimulation frequencies and pulse-widths. A simple rule is introduced to avoid spasm or injury to the leg during FES application. The results from this study show that higher frequency gives faster muscle fatigue and the selection of force required to perform a functional task is important for obtaining the optimum stimulation parameters. Stimulation pulse-width has no significant effect on the muscle fatigue but highly affects the maximum muscle force. The rule proposed is important and is found to be useful to avoid leg injury, spasm or uncomfortable feeling during FES application. This rule also can be used to choose optimum stimulation parameters.

关键词： Muscles Force Fatigue Frequency modulation Neuromuscular stimulation Protocols Torque

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Development of Hamstrings Muscle Model for Paraplegic with Functional Electrical Stimulation

Development of Hamstrings Muscle Model for Paraplegic with F...

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International Conference on Intelligent systems, Modelling and Simulation (ISMS)

作者： R. Jailani M.O. Tokhi Faculty of Electrical Engineering Universiti Teknologi MARA Shah Alam Selangor Darul Ehsan Malaysia Department of Automatic Control and System Engineering University of Sheffield UK

This paper presents the development of paraplegic hamstrings muscle model with Adaptive Neuro-Fuzzy Inference system (ANFIS). A series of experiments using Functional Electrical Stimulation (FES) with different stimulation frequencies, pulse width and pulse duration to investigate the impact on muscle output torque are conducted. The data that is obtained is used to develop the paraplegic hamstrings muscle model. 588 training data and 220 testing data set are used in the development of hamstrings muscle model. The ANFIS hamstrings muscle model is found to be the most accurate muscle model representing paraplegic hamstrings muscle model. The established model is then used to predict the behaviour of the underlying system and will be used in the future for the design and evaluation of various control strategies.

关键词： Muscles Data models Mathematical model Computational modeling Testing Adaptation models Neuromuscular stimulation

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Admissible modeling disturbances for the control of a road sector

Admissible modeling disturbances for the control of a road s...

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International Symposium on Applied Computational Intelligence and Informatics ( SACI)

作者： Catalin Dimon Dumitru Popescu Department of Automatic Control and Systems Engineering Faculty of Automatics and Computer Science University Politehnica of Bucharest Bucharest Romania

Usually when modeling a real process the effects of nonlinearities must be taken into account. A road traffic sector is one such process. Considering it from a macroscopic point of view, the sector is modeled both as a nonlinear and as a linearized process. An 110 model is proposed and a RST control algorithm is used to ensure the imposed performances for the closed loop system. The robustness of the system is obtained by determining the modulus margin and based upon it the admissible nonlinearities are analyzed in order to determine the limits between which the system maintains its stability.

关键词： Analytical models Robustness

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Microcontroller based fuzzy-PI approach employing control surface discretization

Microcontroller based fuzzy-PI approach employing control su...

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Mediterranean Conference on control and Automation (MED)

作者： Jasmin Velagić Muhamed Kurić Edin Dragolj Zlatan Ajanović Nedim Osmić Department of Automatic Control & Electronics Faculty of Electrical Engineering at the University of Sarajevo Zmaja od Bosne Sarajevo Bosnia and Herzegovina

This paper proposes an approach of digital controller design on microcontrollers based on control surface disretization. As experimental setup a simple system composed of a DC motor, the PWM drive and a encoder was built. Identification of this simple system was done using the first order linear model and the Hammerstein-Wiener model. The quality of these models was compared based on the fitness function and their ability to cope with system nonlinearities. A discrete PI speed controller was designed based on the Hammerstein-Wiener model and tuned by the Gauss-Newton optimization algorithm. The Fuzzy logic controller was designed on the basis of the PI controller behaviour with genetic algorithm parameter tuning. The control surface of the Fuzzy logic controller was discretized for microcontroller implementation. Both controllers were implemented on the Arduino Mega platform and their control performances were tested and compared.

关键词： Pulse width modulation Time measurement Niobium

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Performance evaluation of job scheduling algorithms in P2P distributed systems

Performance evaluation of job scheduling algorithms in P2P d...

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The International Conference on Informatics and systems (INFOS)

作者： Tarek Helmy Elsayed Sallam College of Computer Science and Engineering King Fahd University of Petroleum and Minerals Dhahran 31261 Mail Box 413 Saudi Arabia Faculty of Engineering Department of Computers & Automatic Control Engineering Tanta University Egypt

Peer-to-Peer (P2P) distributed systems have received considerable attention mainly due to their potential for high-performance and high-reliability. Job scheduling in P2P distributed systems is one of the most important issues. In this paper, we have evaluated the performance of four job scheduling algorithms named Random, Round Robin, Number of Connections and Server Load in P2P distributed computing environment. The aim of the performance evaluation is to provide a comprehensive view of what performance can be expected from these algorithms in P2P systems in terms of CPU utilization, task processing, traffic received and traffic sent at different load scenarios. We used OPNET modeler to build the simulation model for FTP application on the P2P distributed systems. The output of the performance comparison illustrates different QoS (Quality of Service) aspects of these basic algorithms under different workloads and traffic settings. The results show that the performance of each algorithm changes according to the operational environment setting. The simulation results show that the Server Load-based scheduling algorithm has the best performance among the four algorithms followed by the Number of Connections-based scheduling algorithm. Simulations also show that the Server Load scheduling policy is not suitable for heavy load situations and the Random algorithm is suitable for some settings, especially in the low load situation.

关键词： Portable document format IEEE Xplore

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Fuzzy Logic-Based Scheme for Load Balancing in Grid Services

Fuzzy Logic-Based Scheme for Load Balancing in Grid Services

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Conference on Computer Science and Software engineering(CSSE 2012)

作者： Tarek Helmy Hamdi Al-Jamimi Bashar Ahmed Hamzah Loqman Information and Computer Science Department College of Computer Science and EngineeringKing Fahd University of Petroleum and Minerals “On leave from College of Engineering Department of Computers Engineering & Automatic ControlTanta University

Load balancing is essential for efficient utilization of resources and enhancing the responsiveness of a computational grid, especially that hosts of services most frequently used, i.e. food, health and nutrition. Various techniques have been developed and applied;each has its own limitations due to the dynamic nature of the grid. Efficient load balancing can be achieved by an effective measure of the node's/cluster's utilization. In this paper, as a part of an NSTIP project # 10-INF1381-04 and in order to assess of FAQIH framework ability to support the load balance in a computational grid that hosts of food, health and nutrition inquire services. We detail the design and implementation of a proposed fuzzy-logic-based scheme for dynamic load balancing in grid computing services. The proposed scheme works by using a fuzzy logic inference system which uses some metrics to capture the variability of loads and specifies the state of each node per a cluster. Then, based on the overall nodes' states, the state of the corresponding cluster will be defined in order to assign the newly arrived inquires such that load balancing among different clusters and nodes is accomplished. Many experiments are conducted to investigate the effectiveness of the proposed fuzzy-logic-based scheme to support the load balance where the results show that the proposed scheme achieves really satisfactory and consistently load balance than of other randomize approaches in grid computing services.

关键词： Fuzzy Logic Load Balancing Grid Computing.

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Improved vertex control for a ball and plate system

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IFAC Proceedings Volumes 2012年第13期45卷 400-405页

作者： H.-N. Nguyen S. Olaru P.-O. Gutman M. Hovd SUPELEC Systems Sciences (E3S) – Automatic Control Department Faculty of Civil and Environmental Engineering Technion – Israel Institute of Technology Department of Engineering Cybernetics Norwegian University of Science and Technology

This paper deals with a ball and plate experiment and the objective is twofold. In the first part, a solution to the identification problem for this multi-input multi-output system is provided. In the second part an improved vertex control technique, recently proposed in literature (Nguyen et al. [2011b], Nguyen et al. [2011a]), is applied for stabilizing the ball and plate system. Based on an interpolation technique, feasibility and an asymptotically stable closed loop behavior are guaranteed.

关键词： Improved vertex control Non-minimal state space Interpolation Explicit solution Invariant set Identification

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Interpolation based control for constrained linear time-varying or uncertain systems in the presence of disturbances

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IFAC Proceedings Volumes 2012年第17期45卷 169-174页

作者： H.-N. Nguyen S. Olaru P.-O. Gutman M. Hovd SUPELEC Systems Sciences (E3S) - Automatic Control Department Faculty of Civil and Environmental Engineering Technion - Israel Institute of Technology Department of Engineering Cybernetics Norwegian University of Science and Technology

In this paper, the robust control of constrained discrete-time linear time-varying or uncertain systems affected by bounded additive disturbance is considered. The main idea is to use an interpolation technique between several local unconstrained robust optimal controls. From the implementation point of view, the scheme is shown to be computationally attractive, at each time instant a quadratic programming (QP) problem being solved on-line. The proofs of recursive feasibility of the optimization procedure and ISS stability of the closed loop system are given.

关键词： Interpolation based control Quadratic programming Invariant set ISS Stability

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