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Component Based Tele-Diagnosis Approach to a Textile Machine

IFAC Proceedings Volumes 2001年第9期34卷 157-162页

作者： Armin Wolfram Rolf Isermann Darmstadt University of Technology Institute of Automatic Control Laboratory for Control Engineering and Process Automation Landgraf-Georg-Strasse 4 D-64283 Darmstadt (Germany) Phone: (+49) 6151 167407 Fax: (+49) 6151 293604

The detection and diagnosis of faults in technical systems is of great practical significance. With the help of recent data transfer techniques, service technicians must not necessarily be on-site in order to diagnose the cause of failure. Therefore tele-diagnosis can be defined as a service making use of modern communication channels. However, further progress can be achieved by automating the supervision task. An early detection of faults may help to avoid product deterioration, performance degradation, major damage to the machinery itself and damage to human health or even loss of lives. Furthermore, by employing modern diagnostic systems, faults can even be detected before they lead to a partial or total failure of the plant. This information can be utilised to plan maintenance cycles and thus to minimise plant outages. Within this paper a component-based plant monitoring approach is proposed which relies on the idea that the supervision of complex plants can take place in the individual components.

关键词： Fault Detection and Diagnosis Tele-diagnosis Component-based Maintenance on Demand

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Robust guaranteed cost control with H/sub /spl infin//-/spl gamma/ disturbance attenuation performance

Robust guaranteed cost control with H/sub /spl infin//-/spl ...

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American control Conference (ACC)

作者： Xue Anke Jiang Nan Sun Youxian Automation Department Hangzhou Institute of Electronics Engineering Hangzhou China Institute of industrial Process Control Zhejiang University of Technology Hangzhou China

The paper is concerned with the design of robust guaranteed cost controller with H/sub /spl infin//-/spl gamma/ disturbance attenuation performance for linear systems with norm bounded parameter uncertainties and dist... 详细信息

关键词： Robust control Attenuation Cost function control systems Robustness Riccati equations Optimal control Upper bound Uncertainty Linear systems

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Influences of Braking System Faults on the Vehicle Dynamics

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IFAC Proceedings Volumes 2001年第1期34卷 113-118页

作者： Harald Straky Michael Kochem Jürgen Schmitt Rainer Hild Rolf Isermann Institute of Automatic Control Laboratory of Control Engineering and Process Automation Darmstadt University of Technology Landgraf-Georg-Str. 4 D-64283 Darmstadt. Germany Phone: +496151 16-7412. FAX: +496151 16-7421

From a safety point of view the braking system is, besides the driver, one of the key subsystems in a car. The driver, as an adaptive control system, might not notice small faults in the hydraulic part of the braking system and sooner or later critical braking situations, e.g. due to a brake-circuit failure, may occur. Most of the drivers are not capable to deal with such critical situations. Therefore this paper investigates the influence of faults in the braking system on the dynamic vehicle behavior and the steering inputs of the driver to keep the vehicle on the desired course.

关键词： vehicle dynamics hydraulics brakes failure

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Asset management solution based on PROFIBUS-PA profiles

Asset management solution based on PROFIBUS-PA profiles

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International Conference on Emerging Technologies and Factory automation (ETFA)

作者： M. Wollschlaeger C. Diedrich J. Muller U. Epple Ifak Institut f. Automation U Kommunikation e. V. Magdeburg Barleben Germany Chair of Process Control Engineering PLT RWTH Aachen University of Technology Aachen Germany

ISBN: (纸本)0780372417

Effective solutions for asset management become increasingly important in modern automation and control systems. They are especially required in the area of process control. The control systems used here usually consist of PLC-based networks, which are optimised concerning the special temporal and topological requirements of the process. Asset management functions have to be introduced to those systems, without any influence on the existing equipment. The paper shows an object-oriented solution based on PROFIBUS-PA device. By automatically evaluating a system structure and mapping the profile-relevant parameters of devices to proxy objects, different application modules for asset management functions can be implemented acting on these objects.

关键词： Asset management Automatic control automation control systems process control Data mining Data engineering Field buses Actuators Programmable control

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A new approach for modeling and control of MIMO nonlinear systems

A new approach for modeling and control of MIMO nonlinear sy...

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IEEE Region 10 International Conference TENCON

作者： S. Munzir H.M. Mohamed M.Z. Abdulmuin Process control and automation center Faculty of Engineering University of Malaya Kuala Lumpur Malaysia

Modeling of nonlinear systems is implemented using a partial linear modeling (PLM) technique, which separates the linear and nonlinear part of the model. The linear part of the model is in the form of an ARX model, while the nonlinear part is in the form of NNARX model using an RBF neural network. For the RBF neural network, the centers of the network are chosen using an orthogonal least squares (OLS) method. The linear part of the model is constructed to fit and absorb as much as possible the dynamic of the system, while its residuals are fitted using the nonlinear part of the model. The model is tested on experimental data of a MIMO spark ignition (SI) engine system. The plant (SI engine) is handled as a two-inputs, two-outputs process, the two inputs are the ignition timing and the throttle angle, the two outputs are the engine speed and manifold pressure. Different order and nonlinear terms of model are tested on the input-output data to obtain a valid model. Finally, second order with three nonlinear terms of model is found as a fairly accurate model. Model validation is treated using different sets of input-output data which indicates that the resulting model is fairly valid. A feedback linearization method is used for controlling the nonlinear system where the model is constructed using the PLM technique. The smooth transition of the controller output shows that the combination of the modeling and control technique has real potential for real-time implementation.

关键词： Nonlinear control systems MIMO Nonlinear systems Engines Neural networks Ignition Least squares methods Nonlinear dynamical systems System testing Sparks

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Target value computing in paper machine grade changes by fuzzy system

Target value computing in paper machine grade changes by fuz...

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IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)

作者： P. Viljamaa H. Peltonen H.N. Koivo Automation and Control Institute Tampere University of Technology Tampere Finland Process Research Lappeeranta Finland Control Engineering Laboratory Helsinki University of Technology Finland

A fuzzy system is proposed to compute new target values for low level controllers during grade changes in a paper machine. The fuzzy system is designed and tuned in co-operation with human operators of the paper machine. The design method utilizes both heuristic knowledge and estimation techniques based on input-output data. The input fuzzy sets and the rule base are initially designed verbally and thereafter fine-tuned by a least squares algorithm. An industrial example illustrates the iterative design process. It shows that transparency and a priori knowledge included in the model are preserved also during optimization of the fuzzy model.

关键词： Paper making machines Fuzzy systems control systems Humans Design methodology Fuzzy sets Algorithm design and analysis Least squares methods Iterative algorithms process design

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On-Line Fault Detection of Inverter-Fed Induction Motors Using Advanced Signal processing Techniques

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IFAC Proceedings Volumes 2000年第11期33卷 1119-1124页

作者： Armin Wolfram Rolf Isermann Darmstadt University of Technology Institute of Automatic Control Laboratory for Control Engineering and Process Automation Landgraf-Georg-Strasse 4 D-64283 (Germany) Phone: (+49) 6151 167406 Fax: (+49) 6151 293604

Due to the increasing demands concerning reliability, safety and economy of technical processes, on-line fault detection of induction motors is an important topic in the engineering field. Approaches, based on the spectral analysis of motor currents have been frequently proposed. The main drawback of these approaches has been the restriction on induction machines fed by power supplies with constant frequency. Due to the progress in semiconductor technology and power electronics, inverter-fed induction motors providing a wide speed range are more and more employed. This paper proposes the basics of a nonlinear time-domain transformation which is capable of applying the same spectral analysis scheme for different speeds. Finally, experiments are shown for the detection of insulation failures in the stator windings.

关键词： Induction Motor Inverter Fault Detection Time Warping Signal Analysis Stator Currents Insulation Failure Field-Oriented control

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Fault Detection of a Solenoid Valve for Hydraulic Systems in Vehicles

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IFAC Proceedings Volumes 2000年第11期33卷 119-124页

作者： Olaf Moseler Harald Straky Darmstadt University of Technology Institute of Automatic Control Laboratory of Control Engineering and Process Automation Landgraf-Georg-Strasse 4 D-64283 Darmstadt Germany Phone: +49 - 6151 - 167404 Fax: +49 - 6151 - 293604

In passenger and utility vehicles proportional solenoid valves are used in different hydraulic systems. The valves often have an important impact on the operation quality of succeeding components. However, the correct functioning of the devices is only insufficiently checked. Therefore a novel, model-based approach is going to be presented which is able to estimate the solenoid’s armature stroke based on measured voltage und current. No expensive position sensor is required, that could reduce the overall reliability. Evaluating the reconstructed stroke, faults such as blockade, increased friction, etc. can be detected. But also faults in the electrical part of the valve may be isolated. Instead of replacing whole components in case of a faulty behaviour, the self check of the solenoid valve itself can assist in judging whether the component or the solenoid is faulty. Hence, maintenance costs can be optimized. The paper includes experimental results. Aspects of the microcontroller implementation are addressed.

关键词： Fault Detection Solenoid Hydraulic Valve Microcontroller

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A Smart Actuator with Model-Based FDI Implemented on a Microcontroller

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IFAC Proceedings Volumes 2000年第26期33卷 995-1000页

作者： Olaf Moseler Markus Müller Darmstadt University of Technology Institute of Automatic Control Laboratory of Control Engineering and Process Automation Landgraf-Georg-Strasse 4 D-64283 Darmstadt Germany Phone: +49 - 6151- 167404 Fax: +49 - 6151 - 293604

The device under consideration drives a cabin pressure control valve of modern passenger aircrafts. It is already provided by a wide range of built-in tests. However, these tests do not allow a deep diagnosis of the actuator. Therefore in this paper a model-based approach for detecting and isolating faults is presented. Parameter estimation and parity equations are used for feature generation. The features are compared to that one of the fault-free case. Deviations are fed into a fuzzy rule base in order to isolate the faults. The whole approach is implemented on a 16 bit microcontroller. Experimental results are given.

关键词： Model-Based Fault Detection Fuzzy-Logic Brushless DC Motor Microcontroller

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FIT - Filtering and Identification Tool

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IFAC Proceedings Volumes 2000年第15期33卷 863-868页

作者： Olaf Moseler Michael Vogt Darmstadt University of Technology Institute of Automatic Control Laboratory of Control Engineering and Process Automation Landgraf-Georg-Strasse 4 D-64283 Darmstadt Germany Phone: +49 - 6151 - 167404 Fax: +49 - 6151 - 293604

The program "Filtering and Identification Tool" designed for MATLAB provides an easy to handle tool for linear system identification of continuous time domain systems. But also discrete time models may be identified. The only property the process model must fulfill is that it has to be linear in the parameters. A graphical user interface guides the research engineer through all steps. As most of the time consuming algorithms are implemented as C-functions, the identification even with a huge amount of data takes only few seconds. To identify continuous time process models, derivatives of the input and output signals are required. However, these signals often cannot be measured. Therefore digital filters such as state variable filter (SVF) and differentiating finite impulse response (FIR) filters are integrated into FIT to provide the necessary derivatives. For the identification task various recursive parameter estimation methods like recursive least means squares (RLS), discrete square root filter in information form (DSFI), normalized least means squares (NLMS), etc. are included, too. Recursive algorithms with exponential fading memory (variable step size in case of NLMS) were chosen in order to identify time variant systems. But also for the offline design of real-time fault detection or adaptive control schemes using parameter estimation methods a variable forgetting factor is important to be able to track varying parameters. Thus, the main advantage of the Filtering and Identification Tool in comparison to existing software tools for system identification is the integration of both parameter estimation methods and differentiating filters.

关键词： system identification differentiating filters continuous time models

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