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Photorefractive Effects, Materials, and Devices, PEMD 2005

作者： Dovolnov, Eugene A. Sharangovich, Sergey N. Sheridan, John T. Tomsk State University of Control System and Radioelectronics MQR department 40 Lenin Avenue 634050 Tomsk Russia Department of Electronic and Electrical Engineering Faculty of Engineering and Architecture University College Dublin National University of Ireland Belfield Dublin D-4 Ireland

ISBN: (纸本)1557527938

In the work an analytical model of transmission holographic grating formation by light beams with non-uniform phase-amplitude profiles is presented. The model takes into consideration influence of light absorption of a photopolymer with dye-sensitizer and nonlinearity of photo-polymerization on the spatial profiles and diffraction properties of the chirped grating. The model of diffraction efficiency and selective properties of chirped gratings is also presented. The results of fitting experimental data and numerical ones are shown and discussed. © 2005 OSA/PEMD 2005.

关键词： Light absorption

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Autotuned PI level control in a two-tank-cascade model with sliding control error reference course

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WSEAS Transactions on Circuits and systems 2005年第9期4卷 1077-1084页

作者： Šulc, Bohumil Department of Instrumentation and Control Engineering Czech Technical University in Prague Faculty of Mechanical Engineering Technická 4 166 07 Praha Czech Republic

The results of a controller design are usually tested by means of similation models of the control loop with the designed controller. Linearized versions of the simulation models are often preferred, and the changeable operating conditions are simulated by changes of the model parameters. These parameter changes are normally proposed very heuristically. This may misinterpret the simulation results. In order to test controllers, a suitable model of the controlled plant has been designed in the MATLAB-SIMULINK program. This is presented here, together with a PI controller equipped with autotuning features. The model of the plant takes into account not only the existing non-linear character of the physical phenomena in steady-state relations between inputs and outputs, but also some other phenomena such as saturation, accumulation stopping, technological limits, etc. Such types of models, often referred to as engineering models, are suitable tools for controller testing, especially when their ability to master various operating conditions is examined. In the presented case, the model is used to evaluate the self-tuning capabilities of a PI controller with parameter adaptation via the continuous gradient method. To demonstrate the inadequacy of the usually used methodology, in which certain parameter changes in transfer function representation of the controlled object are proposed by the experimenters themselves without any correspondence to real causes, special attention is paid to the changeability of the linear model parameters of a two-tank cascade independence on the operating point. The simple mathematical description of the physical laws is valid sufficiently exactly, and allows us to examine PI controller parameter adaptation in the newly modified continuous gradient method. This algorithm uses an unconventionally proposed reference model of the desired control error course, which enables us universally to deal with the disturbances and also to set a new operati

关键词： Two term control systems

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Sensor discredibility detection via computational intelligence

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WSEAS Transactions on systems 2005年第11期4卷 1906-1913页

作者： Šulc, Bohumil Klimánek, David Department of Instrumentation and Control Engineering Czech Technical University in Prague Faculty of Mechanical Engineering Technická 4 166 07 Prague Czech Republic

In most of the control loops the controlled variable is transmitted by a sensor. If the sensor stops operating completely, it is easy to recognize this status. However, the sensor may continue to provide data, but the output information from the sensor is biased. Detection of such sensor malfunction can then become a very important problem. Changes of sensor properties are not apparent from the control loop behaviour. Although the biased sensor output information does not lead to failure of the controlled function, we are faced to the problem that, although the control loop seems to work properly, the consequences of such a "small" malfunction (sensor discredibility) can be substantial and expensive. It is easy to imagine, e.g. a combustion ratio control where deviations from an optimal ratio value have no principal influence on the operation of the device, but late discovery of an increase in harmful emissions may be very costly. The discredibility detection may require very expensive measuring equipment (hardware redundancy). In this paper, another way of sensor discredibility detection is shown. It is based on hardware redundancy. This saves the costs of additional measurements;and also supports improvement of the control system function by avoiding hidden impreciseness that otherwise occurs in the control loop operation. The used tools are methods of computational intelligence that have been adapted and evaluated when applied for a two-tank cascade level control.

关键词： Sensor data fusion

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INTEGRATION OF 3D PROXIMITY SCANNER TO ORPHEUS ROBOTIC system

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IFAC Proceedings Volumes 2005年第1期38卷 186-191页

作者： L. Zalud Department of Control and Instrumentation Faculty of Electrical Engineering and Communication Brno University of Technology Kolejní 4 612 66 Brno Czech Republic

Orpheus mobile robot is a teleoperated device primarily designed for remote exploration of hazardous places and rescue missions. The robot is able to operate both indoors and outdoors, is made to be durable and reliable. The device is controlled through advanced user interface with joystick and head mounted display with inertial head movement sensor. To increase the system's operability in difficult conditions (fog, smoke, dark), 3D proximity scanner controlled by on-board processor through Ethernet connection was integrated to it. The scanner also represents a step towards semi-autonomous mode of the robot.

关键词： communication robot robot control telerobotics user interfaces

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A non-invasive system for predicting hemoglobin (Hb) in dengue fever (DF) and dengue hemorrhagic fever (DHF)

A non-invasive system for predicting hemoglobin (Hb) in deng...

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Asian Conference on Sensors and the International Conference on new Techniques in Pharmaceutical and Biomedical Research

作者： A.R. Herlina I. Fatimah T.M. Nasir Department of Control and Instrumentation Engineering Faculty of Electrical Engineering Universiti Teknologi Malaysia Skudai Johor Malaysia Department of Control and Instrumentation Engineering Universiti Teknologi Malaysia Johor Malaysia Department of Biomedical Engineering University of Malaya Kuala Lumpur Malaysia Faculty of Electrical Engineering Universiti Teknologi Mara Shah Alam Selangor Malaysia

Single frequency bioelectrical impedance analysis (BIA) is an inexpensive, quick and painless means of estimating body composition. In this paper, BIA parameters employed for predicting hemoglobin (Hb) in dengue patients. The BIA technique passes a low-amplitude electrical current, in the range of 500 /spl mu/A to 800 /spl mu/A, at a single frequency of 50 kHz. BIA data was sampled from 210 (comprises of 119 males and 91 females) serologically confirmed dengue fever (DF) and dengue hemorrhagic fever (DHF) patients, hospitalized at the Hospital Universiti Kebangsaan Malaysia (HUKM). After applying multiple regression analysis, it was found out that reactance, sex, weight and vomiting were found to be significant independent determinants of predicting Hb.

关键词： Hemorrhaging Diseases Blood Frequency estimation Bioelectric phenomena Impedance Hospitals Shape Instruments Turing machines

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Platform independent neural semi-inverse controller

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WSEAS Transactions on systems 2005年第4期4卷 365-369页

作者： Pivoňka, Petr Schmidt, Michal Department of Control and Instrumentation Faculty of Electrical Engineering and Communication Brno University of Technology Kolejní 4 61200 Brno Czech Republic

The neural network based semi-inverse controller is similar to an inverse controller. An inverse controller uses an inverse model of the controlled plant. On the other hand, the semi-inverse controller is based on a forward model of the plant. This avoids some of the problems of inversion. The algorithm is suitable for implementation in a PLC. For maximum portability of the algorithm between the development environment and its final implementation in the PLC, the algorithm is implemented on top of an abstract object-oriented layer, which provides platform independency.

关键词： Neural networks

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Generalized predictive control with adaptive model based on neural networks

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WSEAS Transactions on Circuits and systems 2005年第4期4卷 385-388页

作者： Pivoňka, Petr Nepevný, Petr Department of Control and Instrumentation Faculty of Electrical Engineering and Communication Brno University of Technology Kolejní 4 61200 Brno Czech Republic

Generalized Predictive control (GPC) is well known control algorithm. If we put together predictive strategy of GPC and Neural Network model, which is adaptive, then we obtain new controller with many advantages. Neural model is able to observe system changes and adapt itself, therefore regulator based on this model is adaptive. Algorithm was implemented in MATLAB-Simulink with aspect of future implementation to Programmable Logic controller (PLC) B&R. It was tested on mathematical and physical models in soft-real-time realization. Predictive controller in comparison with classical PSD controller and it's advantages and disadvantages are shown.

关键词： Predictive control systems

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A LABORATORY SCALE PLANT WITH HYBRID DYNAMICS AND REMOTE ACCESS VIA INTERNET FOR control engineering EDUCATION

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IFAC Proceedings Volumes 2005年第1期38卷 1-6页

作者： J. Hlava B. Ŝulc J. TamáŜ Technical University of Liberec Faculty of Mechatronics Department of Control Engineering 416 17 Liberec Hálkova 6 Czech Republic Czech Technical University in Prague Faculty of Mechanical Engineering Institute of Instrumentation and Control Engineering 166 07 Praha 6 Technická 4 Czech Republic

The major challenge in modern control engineering education is to bring the increasingly sophisticated theory closer to those students who will follow industrial careers. Hybrid system theory addresses practical needs, but its potential is usually not understood by people from industry. Presented laboratory scale plant designed for original educational experiments with hybrid systems is a contribution to introducing this theory at a practical level. The paper includes a description of the plant structure, an outline of the mathematical model and suggested control experiments. The proposed internet access solves the lack of such laboratory set-ups. Web services architecture provides a standards-based access to all who want to learn about the principles of hybrid systems through remote experiments.

关键词： hybrid systems control education remote experiments Internet man-experiment interface

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Grid-connected Photovoltaic system with Maximum Power Point Tracking using Self-Organizing Fuzzy Logic controller

Grid-connected Photovoltaic System with Maximum Power Point ...

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International Conference on Power Electronics and Drive systems (PEDS)

作者： N. Khaehintung C. Kangsajian P. Sirisuk A. Kunakorn Department of Control and Instrumentation Engineering Faculty of Engineering Mahanakom University of Technology Bangkok Thailand Department of Computer Engineering Faculty of Engineering Mahanakom University of Technology Bangkok Thailand Department of Power Engineering Faculty of Engineering King Mongkut''s Institute of Technology Ladkrabang Bangkok Thailand

This paper presents the design of a controller for the maximum power point tracking of a grid-connected photovoltaic energy conversion system. A boost converter is used in the system to deliver the output from the solar array to DC-AC inverter, and feed the power into the AC grid. A self-organizing fuzzy logic controller is introduced for the tracking algorithm. The duty ratio for the operation of the boost converter is optimally adjusted in such a way that the maximum power point, which normally varies according to the environment, can be achieved. We demonstrate via the simulation results that our proposed technique outperforms over the conventional fuzzy logic controller in terms of tracking speed and transient response. Furthermore, the algorithm implementation can be done using a look-up table, hence a high-performance, cost-effective real-time maximum power point tracking can be simply realized

关键词： Photovoltaic systems Fuzzy logic control systems Power engineering and energy Solar power generation Energy conversion Inverters Table lookup Optimal control Fuzzy control

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Adaptive controller with identification based on neural network for systems with rapid sampling rates

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WSEAS Transactions on systems 2005年第4期4卷 385-388页

作者： Veleba, Václav Pivoňka, Petr Department of Control and Instrumentation Faculty of Electrical Engineering and Communication Brno University of Technology Kolejní 4 612 00 Brno Czech Republic

In this paper ability of three identification methods to parameter estimation of the dynamic plant with great ratio of its time constant to sampling periods is compared. We concentrate our attention on dealing with adverse effects that work on real-rime identification of process, especially quantization. It is shown, that a neural network applied to on-line identification process produces more stable solution in the rapid sampling domain. Taking advantage of this result, we propose here an adaptive controller with a neural network as on-line estimator. Simple heuristic synthesis based on modified Ziegler-Nichols open loop method (Z-N I) are discussed, that deals with bad-estimated model of a plant and gives numerically stable parameters of the PID discrete controller.

关键词： Adaptive control systems

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