The integration of mechanical systems and microelectronics opens many new possibilities for process design and automatic functions. After discussing the mutual interrelations between mechanical and electronic design t...
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The integration of mechanical systems and microelectronics opens many new possibilities for process design and automatic functions. After discussing the mutual interrelations between mechanical and electronic design the different ways of integration within mechatronic systems and the resulting properties are described. The information processing can be organized in multilevels, ranging from low-level control, through supervision to general process management. In connection with knowledge bases and inference mechanisms intelligent control systems result. The design of control systems for mechanical systems is described, from modeling, identification to adaptive control for nonlinear systems. This is followed by solving supervision tasks with fault diagnosis. Then design tools for mechatronic systems are considered and examples of applications are given, like intelligent control of an electromechanical throttle actuator and force and torque reconstruction for a robot.
作者:
Konrad, HInstitute of Automatic Control
Technical University of Darmstadt Laboratory of Control Engineering and Process Automation Landgraf-Georg-Str.4 D-64283 Darmstadt Germany
In this paper a new method of fault detection in milling is reported. Based on measured cutting forces, model parameters are estimated for each insert of the milling cutter. Using a classifier, the patterns of these e...
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In this paper a new method of fault detection in milling is reported. Based on measured cutting forces, model parameters are estimated for each insert of the milling cutter. Using a classifier, the patterns of these estimated parameters are processed further, and the state of the milling process is determined. The method was first tested with simulated data, and then verified with measurements on a machining center.
Faults which appear in technical processes can often be described as additive or multiplicative faults with respect to the process model. To perform fast detection of these faults, continuous-time parity equations are...
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Faults which appear in technical processes can often be described as additive or multiplicative faults with respect to the process model. To perform fast detection of these faults, continuous-time parity equations are used. Parameter deviations are estimated directly from residuals, providing information about their size. The combined method enables one to distinguish between additive and parametric faults. In case of time-variant processes with slow parameter changes, the coefficients of the parity equations can also be adapted with respect to the tracked parameters. The problem of persistent process excitation for estimation is by-passed. The fault-detection scheme is demonstrated on a permanently excited d.c. motor on a laboratory rig. Its properties, and the experimental results, are discussed.
This paper discusses on-line identification of time-variant nonlinear dynamic systems. A neural network (LOLIMOT, [1]) based on local linear models weighted by basis functions and constructed by a tree algorithm is in...
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This paper considers the application of neural network with distributed dynamics to the identification of nonlinear systems. The main intention is to provide a simulation tool to the development engineer. The identifi...
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This paper considers the application of neural network with distributed dynamics to the identification of nonlinear systems. The main intention is to provide a simulation tool to the development engineer. The identification of the thermal plant is accomplished without any a priori knowledge about the nonlinear structure or the dynamics of the plant. Identification results of two different neural nets are shown and compared. The application area is boilers for building energy management systems.
We propose a new method for fuzzy rule extraction from data by a genetic algorithm and a fine tuning of the extracted membership functions by a constrained nonlinear optimization. This approach is able to select the m...
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We propose a new method for fuzzy rule extraction from data by a genetic algorithm and a fine tuning of the extracted membership functions by a constrained nonlinear optimization. This approach is able to select the most significant rules out of a set of all possible ones, that is it learns the rule structure by itself. The genetic algorithm does not limit the kind of operator and the number and form of the membership functions for the inputs. However, in order to utilize linear optimization techniques, singletons and center of gravity defuzzification are used on the output side. Since each rule premise may include a conjunction of a variable number of inputs (between one and the input dimension), the "curse of dimensionality" can be overcome, that is the number of rules does not increase exponentially with the input dimension. This feature makes the proposed algorithm especially attractive for interpretation of high dimensional nonlinear mappings that are hard to visualize. The strategy followed by the nonlinear optimization of the fuzzy input membership functions focuses on a good interpretability rather than on best approximation performance. This will be demonstrated on a real world data example.
作者:
Rolf IsermannInstitute of Automatic Control
Laboratory of Control Engineering and Process Automation Technical University of Darmstadt Landgraf-Georg-Str 4 D-64283 Darmstadt Germany
The integration of mechanical processes and microelectronics towards mechatronic systems opens new possibilities as well for the design of mechanical components as for automatic functions. The contribution discusses f...
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The integration of mechanical processes and microelectronics towards mechatronic systems opens new possibilities as well for the design of mechanical components as for automatic functions. The contribution discusses first the involved mechanical components and machines and the ways of integration. Then the different automation functions are described in the frame of intelligent control systems which contain multilevel control functions, a knowledge base, and inference mechanisms. Multilevel feedback control for mechanical systems comprises lower level and higher level control, including e.g. nonlinear adaptive control and fuzzy control. The inclusion of model based supervision and fault diagnosis is a further development step. Two examples of mechatronic systems for cars are shown, like an adaptive suspension system and selftuning damping of drive chain oscillations.
A general procedure for model based fault detection and diagnosis is first described. It comprises the steps of a knowledge based approach by merging analytical and heuristic knowledge. Model based fault detection met...
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A general procedure for model based fault detection and diagnosis is first described. It comprises the steps of a knowledge based approach by merging analytical and heuristic knowledge. Model based fault detection methods are summarized together with underlying fault models and appropriate combinations are proposed. Then fault diagnosis based on analytical and heuristic symptoms by using methods of approximate reasoning with fuzzy-logic is briefly described. Finally the practical application for an automotive electro-mechanical actuator is shown.
Faults which appear in technical processes can often be described as additive or multiplicative faults with respect to the process model. To perform fast detection of these faults continuous-time parity equations are ...
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Faults which appear in technical processes can often be described as additive or multiplicative faults with respect to the process model. To perform fast detection of these faults continuous-time parity equations are used. Parameter deviations are estimated directly from residuals providing information about their size. The combined method enables to distinguish between additive and parametric faults. In case of time variant processes with slow parameter changes the coefficients of the parity equations can also be adapted with respect to the tracked parameters. The problem of persistent process excitation for estimation is by-passed. The fault detection scheme is demonstrated at a permanently excited *** on a laboratory rig. Its properties and the experimental results are discussed.
Servo systems play an important role in many automated processes. In order to fulfil the hard demands on reliability and fast and precise operation, intelligent concepts for the control, supervision and (reconfigurati...
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Servo systems play an important role in many automated processes. In order to fulfil the hard demands on reliability and fast and precise operation, intelligent concepts for the control, supervision and (reconfiguration are necessary. In this paper, an approach is presented which integrates different levels of signal processing in an electromechanical servo system. The digital controller and the model-based fault detection scheme are designed taking into account model-uncertainty and the time variant process behaviour, which is caused by temperature influences. After a brief description of the theoretical basis an experimental application shows results for an automobile servo system which is driven by a d.c. motor.
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