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作者： Peng, Z.K. Zhang, W.M. Lang, Z.Q. Meng, G. Chu, F.L. State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China Department of Automatic Control and Systems Engineering University of Sheffield Mappin Street Sheffield S1 3JD United Kingdom Department of Precision Instruments Tsinghua University Beijing 100084 China

To overcome the inherent deficiencies of conventional timefrequency analysis (TFA) methods, i.e., different TFA methods or the same TFA method with different control parameters will present different results for the same target signal, a novel scheme named as the timefrequency data fusion (TFDF) is developed in this study by extending the idea of data fusion technique. By combining the results produced by two or more different TFA methods, the TFDF technique can present a more accurate timefrequency presentation for the target signal than what can be achieved by any individual TFA method. Therefore, the TFDF has potential to render a significantly improved timefrequency representation and greatly facilitates extracting timefrequency features of target signals. This will promote the applications of TFA in engineering practices and make TFA methods more acceptable to field engineers. The effectiveness of the TFDF technique is validated by three numerical case studies and the analysis of a rubbing-impact signal collected from a rotor test rig. © 2011 Elsevier Ltd. All rights reserved.

关键词： Wavelet transforms

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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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Impulse response estimation with binary measurements: a regularized FIR model approach

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IFAC Proceedings Volumes 2012年第16期45卷 113-118页

作者： Tianshi Chen Yanlong Zhao Lennart Ljung Division of Automatic Control Department of Electrical Engineering Linköping University Linköping Sweden Key Laboratory of Systems and Control Institute of Systems Science Academy of Mathematics and System Science Chinese Academy of Sciences Beijing China

FIR (finite impulse response) model is widely used in tackling the problem of the impulse response estimation with quantized measurements. Its use is, however, limited, in the case when a high order FIR model is required to capture a slowly decaying impulse response. This is because the high variance for high order FIR models would override the low bias and thus lead to large MSE (mean square error). In this contribution, we apply the recently introduced regularized FIR model approach to the problem of the impulse response estimation with binary measurements. We show by Monte Carlo simulations that the proposed approach can yield both better accuracy and better robustness than a recently introduced FIR model based approach.

关键词： Impulse response estimation regularization quantization

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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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Simulator for control and Automation using an interactive and configurable 3D virtual environment

Simulator for Control and Automation using an interactive an...

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Society of Instrument and control Engineers Annual Conference

作者： Adolfo Sanchez del Pozo Juan Manuel Escano Carlos Bordons Department of System Engineering and Automatic Control University of Seville

ISBN: (纸本)9781467322591

The use of simulators greatly facilitates the work of specialists. Their usage produces results that could prevent errors in real systems. Using a simulator for industrial plants would reduce the programming time of their automation. We propose to develop a simulation platform of industrial machinery with 3D virtual reality, to carry out experiments of PLC (Programable Logic controllers) programming. A physic engine will be needed to be integrated in the application with a graphic interface which will be used to design, to programm and to visualize the simulation of the plant. Showing the first results of a first prototype, being the most general possible in programming to demonstrate the possibilities of such software both educational and commercial.

关键词： Simulator 3D Virtual reality PLC Industrial Collision OPC

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Reference governor design with guarantees of detection for delay variation

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IFAC Proceedings Volumes 2012年第14期45卷 67-72页

作者： Nikola Stanković Florin Stoican Sorin Olaru Silviu-Iulian Niculescu SUPELEC System Sciences (E3S - Automatic Control Department Gif-sur-Yvette France Norwegian University of Science and Technology - Department of Engineering Cybernetics Trondheim Norway SUPELEC-CNRS LSS - Laboratory of Signals and Systems Gif-sur-Yvette France

The present paper deals with fault tolerant control for linear dynamics with additive disturbances. The control action is generated based on information collected from a redundant, multi-sensors network. Delays that may appear during plant measurements transmission through real communication channels are considered as faults. Depending on presence of delay in feedback loop, different invariant sets can be computed. We show that fault tolerant control can be achieved through invariant sets separation with respect to different delay values. Sets separation is accomplished for specific values of the reference signal. Therefore, we introduce in the loop a reference governor which is designed by a receding horizon technique. Thus, we provide reference signals which practically guarantee fault detection and identification in real time.

关键词： Fault tolerance Time-Delay systems Set invariance

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Period distribution analysis of some linear maps

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Communications in Nonlinear Science and Numerical Simulation 2012年第10期17卷 3848-3856页

作者： Fei Chen Xiaofeng Liao Kwok-wo Wong Qi Han Yang Li State Key Lab. of Power Transmission Equipment and System Security College of Computer Science Chongqing University Chongqing 400044 PR China Department of Electronic Engineering City University of Hong Kong Hong Kong PR China Department of Automatic Control and Systems Engineering The University of Sheffield UK

This paper discusses period properties of some linear maps which are employed in various applications such as image encryption, public key cryptography and watermarking. Conditions for the bijectiveness of such maps and the existence of a period are presented. Period structure is also given. Then, the recurrence equation theory is adopted to address the period distribution problem. Finally, a framework to solve the problem is proposed with a demonstration of its effectiveness and efficiency into some applications.

关键词： Linear map Period distribution Periodic orbit Dynamical system Cat map

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Extending CSP to detect motor imagery in a four-class BCI

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Journal of Information and Computational Science 2012年第1期9卷 143-151页

作者： Fang, Yonghui Chen, Minyou Zheng, Xufei Harrison, R.F. State Key Laboratory of Power Transmission Equipment and System Security New Technology Chongqing University Chongqing 400044 China School of Electronic and Information Engineering Southwest University Chongqing 400715 China College of Computer Science Sichuan University Chengdu 610065 China Department of Automatic Control and Systems Engineering University of Sheffield United Kingdom

Brain Computer Interface (BCI) provides a direct communication channel from brain to peripheral equipment. Common Spatial Patterns (CSP) is wildly used to extract features for electroencephalogram (EEG). However, basic CSP only suits two-class discrimination and is unable to solve multi-class discrimination problems. This paper proposes a modified CSP method termed Bisearch Common Spatial Patterns (BCSP) to solve a four-class BCI problem. In BCSP, the Fisher's Linear Discriminant Analysis (LDA) is used to discriminate among the four motor imagery tasks. The BCSP can effectively reduce the number of the basic CSP, and thus makes the overall classification procedure more efficient. The Graz BCI data set from the BCI 2008 competition be used to verify the effectiveness of the BCSP. Simulation results show that BCSP has better performance than other extension schemes. © 2012 Binary Information Press January 2012.

关键词： Brain computer interface

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Poster:Development of dynamic leg joint model for paraplegic with Functional Electrical Stimulation

Poster:Development of dynamic leg joint model for paraplegic...

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1st IEEE International Conference on Computational Advances in Bio and Medical Sciences, ICCABS 2011

作者： Bijanzadeh, M. Jailani, R. Tokhi, M.O. Gharooni, S.C. Department of Automatic Control and System Engineering University of Sheffield United Kingdom

ISBN: (纸本)9781612848525

This paper presents the development of paraplegic joint model using Artificial Neural Network (ANN). A series of experiments using Functional Electrical Stimulation (FES) with different stimulation frequencies, pulse width and pulse duration to investigate the impact on the leg swing angle is conducted. The data obtained is used to develop the paraplegic leg joint model. 74810 training data and 33602 testing data set are used in the development of joint model. The joint model thus developed is validated with clinical data from one paraplegic subject. Two modelling strategies were used to model the leg joint which the ANN joint model is found to be the most useful joint model representing paraplegic leg. 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. © 2011 IEEE.

关键词： Neural networks

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Feature extraction of motor imagery in BCI with approximate entropy

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Journal of Computational Information systems 2012年第6期8卷 2485-2491页

作者： Fang, Yonghui Chen, Minyou Zheng, Xufei Harrison, Robert F State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University Chongqing 400044 China School of Electronic and Information Engineering Southwest University Chongqing 400715 China College of Computer Science Sichuan University Chengdu 610065 China Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom

Approximate Entropy (ApEn) is a regularity statistic that quantifies the unpredictability of fluctuations in a time series and can classify complex systems. This study, ApEn is used to extract features from motor imagery Electroencephalogram (EEC) that containing two motor imagery tasks. This method is different from the traditional way to get the character from EEC. Appropriate parameters must been chosen for different dataset. Two datasets are used in this paper. One comes from BCI Competion2003, the other from the lab of Electromagnetic theory and artincal intelligence, Chongqing University. The results show that ApEn can extract different features in left-hand and right-hand motor imagery EEC efficiently. Comparison between ApEn and Fast Fourier Transform (FFT) shows that ApEn has good capability to the two imagery tasks Brain Computer Interface. © 2012 Binary Information Press.

关键词： Electroencephalography

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