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Hybrid Orthosis: The Technology for Spinal Cord Injury

Journal of Applied Sciences 2010年第22期10卷 2785-2792页

作者： Jailani, R. Tokhi, M.O. Gharooni, S. Department of Automatic Control and System Engineering University of Sheffield United Kingdom Faculty of Electrical Engineering Universiti Teknologi MARA Selangor Malaysia

Hybrid ohosis combined Functional Electrical Stimulation (FES) with a lower limb ohotic brace. The first hybrid ohosis system is introduce in 1972 and since many researchers began to produced hybrid orthosis from complex research devices to nearly commercialized products. The purpose of this study is to provide a review of hybrid ohosis available for rehabilitation of paraplegics. Ths review should provide a guide to biomedcal engineers to understand the tools developed the design characteristics, the advantages and disadvantages of hybrid ohosis that strive to improve paraplegic mobility especially in walking. © 2010 Asian Network for Scientific Information.

关键词： Functional electric stimulation

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A robust wind turbine control using a Neural Network based wind speed estimator

A robust wind turbine control using a Neural Network based w...

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International Joint Conference on Neural Networks (IJCNN)

作者： Oscar Barambones Department of Automatic Control and System Engineering University of Basque Country (UPV-EHU) Vitoria Spain

Modern wind turbines are capable to work in variable speed operations. These wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed generators is that they improve the system efficiency compared to fixed speed generators because turbine speed is adjusted as a function of wind speed to maximize output power. In this sense, to implement maximum wind power extraction, most controller designs of the variable-speed wind turbine generators employ anemometers to measure wind speed in order to obtain the desired optimal generator speed. In this paper a Neural Network based wind speed estimator for a wind turbine control is proposed. The design uses a feedforward Artificial Neural Network (ANN) to implement a wind speed estimator. In this work, a sliding mode control for variable speed wind turbines is also proposed. The stability analysis of the proposed controller is provided under disturbances and parameter uncertainties by using the Lyapunov stability theory. Finally simulated results show, on the one hand that the proposed control scheme using an ANN estimator provides high-performance dynamic characteristics, and on the other hand that this scheme is robust under uncertainties that usually appear in the real systems and under wind speed variations.

关键词： Wind turbines Wind speed Artificial neural networks Generators Rotors Blades Stators

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Modeling, control and robustness analysis for a road sector

Modeling, control and robustness analysis for a road sector

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作者： Dimon, Catalin Dauphin-Tanguy, Geneviève Popescu, Dumitru Department of Automatic Control and System Engineering University Politehnica of Bucharest 313 Splaiul Independentei 060042 Bucharest Romania LAGIS Ecole Centrale de Lille Cité Scientifique BP 48 59651 Villeneuve d'Ascq Cedex France

ISBN: (纸本)9783902661814

When modeling a real process the effects of nonlinearities must be taken into account, especially when designing a control algorithm. Such is the case of a road traffic sector, which will be considered from a macroscopic point of view. An input-output model is proposed, based on experimental data, and then a control algorithm is used to obtain imposed performances for the closed loop system. The robustness of control is taken into account, by assessing the modulus margin. Based on this indicator the robustness of the control law is analyzed in order to find what nonlinearities it can cope with. Following, we try to prove that the system can be controlled using the same algorithm, when different types of perturbations affect the system. © 2010 IFAC.

关键词： Closed loop systems

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Parameter Optimization of FES-Assisted Indoor Rowing Exercise Using MOGA

Parameter Optimization of FES-Assisted Indoor Rowing Exercis...

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Asia International Conference on Modeling & Simulation

作者： Zakaria Hussain M. Osman Tokhi Rozita Jailani Fadzil Ahmad Department of Automatic Control and System Engineering University of Sheffield UK Faculty of Electrical Engineering Universiti Teknologi Mara Malaysia

ISBN: (纸本)9781424471966;9780769540627

This paper describes the parameter optimization of fuzzy logic control (FLC) of FES-assisted indoor rowing exercise (FES-rowing) using multi objective genetic algorithm (MOGA). The indoor rowing exercise is introduced as a total body exercise for rehabilitation of function of lower extremities through the application of functional electrical stimulation (FES). FLC is used to control the knee and elbow trajectories for smooth rowing manoeuvre. MOGA is implemented in Matlab with a dynamic simulation model of indoor rowing exercise is developed using Visual Nastran (vN4D) software environment. MOGA is used to optimize the FES-rowing with two objective functions specified that are i) to minimize the mean squared error of knee angle trajectory and ii) to minimize the total electrical stimulation required by the muscles. In view of good results obtained, it is concluded that MOGA is able to obtain the optimal design of FLC for FES-rowing with two conflicting objectives.

关键词： Knee Fuzzy logic Genetic algorithms Extremities Application software Neuromuscular stimulation Elbow Mathematical model Electrical stimulation Muscles

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Basic principles of hybrid excitation PM synchronous generator utilizing harmonic for excitation

Basic principles of hybrid excitation PM synchronous generat...

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2010 International Conference on Electrical Machines and systems, ICEMS2010

作者： Xia, Yonghong Wang, Shanming Ma, Mingyuan Hao, Liangliang Qiu, Arui Huang, Shaogang State Key Laboratory of Control and Simulation of Power System and Generation Equipments Department of Electrical Engineering Tsinghua University Beijing 100084 China Department of Electrical and Automatic Engineering Nanchang University Nanchang Jiangxi 330031 China

A novel method, which utilizes harmonic for excitation, is presented to adjust the air-gap magnetic field for permanent magnet synchronous machine. The structure and basic principles of the hybrid excitation PM synchronous generator(HEPMSG) are introduced. The no-load and on-load electromagnetic field are calculated based on finite element method, and the waveform and effective value of the winding voltage and characteristics of the machine are gained for different loads. Calculation results demonstrate the new hybrid excitation scheme is feasible. This new method combines the advantages of PM machines and electrical excitation machines. The machine removes the brushes and slip rings, which makes permanent magnet machine keep simple and highly reliable.

关键词： Windings Harmonic analysis Stator windings Rotors Reactive power Power system harmonics

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Development of secure encoder-decoder for JPEG images

Development of secure encoder-decoder for JPEG images

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International Conference on Computer engineering and systems

作者： Ghada Hamissa Amany Sarhan Hatem Abd Elkader Mahmoud Fahmy Electrical Engineering Department Faculty of Engineering KFS University Kafr el-Sheikh Egypt Information System Department Faculty of Computer & Information Menoufia University Menoufia Egypt Computer & Automatic Control Department Computer & Automatic Control Department Tanta University Tanta Egypt Computer & Automatic Control Department Faculty of Engineering Tanta University Tanta Egypt

Digital image copyrights and image authentication draw a great attention specially in critical image communications. This paper presents a proposal for a new encoder-decoder, which we call SecEncoDeco, for securing JPEG images. An extra stage of security is embedded in the traditional JPEG codec. This security stage uses the Secure Hill cipher technique. This encryption technique has many advantages over the traditional Hill cipher. The Safe Time of the Secure Hill cipher is deduced and presented in detail. Implementation of the proposed method is built based on MATLAB. Complete evaluation for the proposed codec is performed which indicates the effectiveness of the proposed secure codec for image copyright protection.

关键词： Image coding Encryption Transform coding Computer architecture Decoding Time measurement

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PID control of Knee Extension for FES-Assisted Walking with Spring Brake Orthosis

PID Control of Knee Extension for FES-Assisted Walking with ...

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Asia International Conference on Modeling & Simulation

作者： R. Jailani M.O. Tokhi S.C. Gharooni Z. Hussain Department of Automatic Control and System Engineering University of Sheffield UK Faculty of Electrical Engineering Universiti Teknologi MARA Shah Alam Malaysia

ISBN: (纸本)9781424471966

This paper presents a simulation of bipedal locomotion to control the stimulation pulses of functional electrical stimulation (FES) for activating muscles for paraplegic walking with spring brake orthosis (SBO). The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO). This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D) dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Proportional integral derivative (PID) control is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The results show that SBO can reduce torque and stimulation pulses required for FES-assisted paraplegic walking with wheel walker and PID control is found to be appropriate controller for the leg extension.

关键词： Three-term control Knee Legged locomotion Springs Muscles Motion control Mathematical model Wheels Torque control Neuromuscular stimulation

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Fuzzy logic control of knee extension for FES-assisted walking with spring brake orthosis

Fuzzy logic control of knee extension for FES-assisted walki...

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IEEE International Conference on systems, Man and Cybernetics

作者： R. Jailani M.O. Tokhi S.C. Gharooni Department of Automatic Control and system Engineering University of Sheffield UK Faculty of Electrical Engineering Universiti Teknologi MARA Shah Alam MALAYSIA

This paper presents a simulation of bipedal locomotion to control the stimulation pulses of functional electrical stimulation (FES) for activating muscles for paraplegic walking with spring brake orthosis (SBO). The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO). This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D) dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Fuzzy logic control (FLC) is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The results show that SBO can reduce torque and stimulation pulses required for FES-assisted paraplegic walking with wheel walker and FLC is found to be appropriate controller for the leg extension.

关键词： Niobium Variable speed drives Muscles

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The Effectiveness of Body Weight Transfer in FES-Assisted Walking with Wheel Walker

The Effectiveness of Body Weight Transfer in FES-Assisted Wa...

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International Conference on Computer Modeling and Simulation, UKSIM

作者： Rozita Jailani M. Osman Tokhi Zakaria Hussain Department of Automatic Control and System Engineering University of Sheffield UK Faculty of Electrical Engineering Universiti Teknologi MARA Shah Alam Malaysia

ISBN: (纸本)9781424466146;9780769540160

This paper describes the development of a fuzzy control scheme for functional electrical stimulation, (FES)-assisted paraplegic walking with wheel walker. The simulation in this study starts with a model of humanoid with wheel walker using the Visual Nastran (Vn4D) dynamic simulation software. The humanoid model is designed based on anthropometric data. Two stimulated muscle models, quadriceps and hamstrings, are developed for knee extension and flexion. A fuzzy logic controller is designed to control the walking gait. It is designed in Matlab/Simulink to regulate the muscle stimulation pulse width required to drive FES-assisted walking gait. The body weight transfer technique is introduced to improve the paraplegic walking performance. The results show that body weight transfer can reduce torque required for FES-assisted paraplegic walking with wheel walker.

关键词： Legged locomotion Wheels Biological system modeling Mathematical model Muscles Fuzzy control Neuromuscular stimulation Knee Fuzzy logic Space vector pulse width modulation

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A robust position control for induction machines

A robust position control for induction machines

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International Conference on Electrical Machines, ICEM

作者： Oscar Barambones Jose Maria Gonzalez de Durana Luis Miguel Camarero Department of Automatic Control and System Engineering and Luis Miguel Candanedo Department of Chemical Engineering and Environment University of Basque Country (UPV-EHU) Vitoria Spain

A robust position control for induction motors using field oriented control theory is presented. The proposed controller is based on variable structure control and provides global asymptotic position tracking in the presence of unknown parameters and load torque variations. The proposed design incorporates an improved method of flux estimation that operates on the principle of flux and current observer. The proposed observer is basically an estimator that uses a plant model and a feedback loop with measured stator voltages and currents. The stability analysis of the proposed controller under parameter uncertainties and load disturbances is provided using the Lyapunov stability theory. Finally simulated results show that the proposed controller with the proposed observer provides high-performance dynamic characteristics and that this scheme is robust with respect to plant parameter variations and external load disturbances.

关键词： Induction motors Equations Rotors Mathematical model Torque Observers Stators

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