The minimal model structure detection (MMSD) problem in nonlinear dynamic system identification is formulated as a search for the optimal orthogonalization path. While an exhaustive search for a model with 20 candidat...
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The minimal model structure detection (MMSD) problem in nonlinear dynamic system identification is formulated as a search for the optimal orthogonalization path. While an exhaustive search for a model with 20 candidate terms would involve 2.43 x 10(18) possible paths, it is shown that this can typically be reduced to 2 x 10(3) by augmenting the orthogonal estimation algorithm with genetic search procedures. The MMSD algorithm provides the first practical solution for optimal structure detection in NARMAX modelling, training neural networks and fuzzy systems modelling. Based on the MMSD algorithm, a refined forward regression orthogonal (RFRO) algorithm is developed. The RFRO algorithm initially detects a parsimonious model structure using the forward regression orthogonal algorithm and then refines the model structure by applying the MMSD algorithm to the reduced model term set. The RFRO algorithm cannot guarantee to find the minimal model structure, but it is computationally more efficient than the MMSD algorithm and can find a smaller model than the forward regression orthogonal algorithm.
This study presents a new algorithm for nonlinear rational model identification. The new algorithm consists of a two-step procedure: a nonlinear rational function smoother is initially designed and used to smooth the ...
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This study presents a new algorithm for nonlinear rational model identification. The new algorithm consists of a two-step procedure: a nonlinear rational function smoother is initially designed and used to smooth the data, system identification is then performed based on the smoothed signal. By using the smoothed signal instead of the raw data, the severe noise problems which arise in rational model identification are avoided. The new approach significantly simplifies the procedure for dynamic nonlinear rational model identification, compared with earlier estimators, and provides unbiased estimates with the same degree of accuracy.
This paper proposes a robust method for automatic tuning of parameters of a discrete PID controller. The tuning rules for SISO and MIMO systems are based on automatic determination of critical gain and critical freque...
This paper proposes a robust method for automatic tuning of parameters of a discrete PID controller. The tuning rules for SISO and MIMO systems are based on automatic determination of critical gain and critical frequency from the estimated model parameters. The plant model can be expressed by a transfer function in continuous and/or discrete form or by differential and/or difference equation. A simple control law using Takahashi discrete form is proposed. Simulations results prove that it is easy to use being able to handle minimum and nonminimum phase plant as well.
In this paper, we propose an adaptive forward-backward-forward splitting algorithm for finding a zero of a pseudo-monotone operator which is split as a sum of three operators: the first is continuous single-valued, th...
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In this paper a soaking pit/rolling mill process model is developed for a real industrial steel mill based on extended coloured Petri nets (ECPN). Both the discrete events and the continuous dynamics involved in the p...
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In this paper a soaking pit/rolling mill process model is developed for a real industrial steel mill based on extended coloured Petri nets (ECPN). Both the discrete events and the continuous dynamics involved in the process are modelled in a unified framework, allowing better investigation of the interactions between these two parts. Corresponding ECPN diagrams are given for the critical components involved in the soaking pit/rolling mill process, including the arrival of hot ingots, the charging and discharging of soaking pits, the soaking process, the preheat furnace operation, the mill operation, etc. The ECPN diagrams are implemented in the Design/CPN environment in a Sun SPARC workstation. Computer simulations are carried out and typical results are shown, which are helpful for the improvement of soaking pit/rolling mill operations.
作者:
IHARA, JSystems Engineering Section
Automatic Control Division Electrotechnical Laboratory Ministry of International Trade and Industry Tokyo Japan
A vector measure is discussed which makes available the full information as to the fitness of a model contained implicitly in the mean square error. The vector measure is called the fitting characteristic vector (FCV)...
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A vector measure is discussed which makes available the full information as to the fitness of a model contained implicitly in the mean square error. The vector measure is called the fitting characteristic vector (FCV) in the paper. Dimensionless quantities of three kinds are extracted from the mean square error. The FCV is defined by these quantities. It is shown that each of the quantities has its own intrinsic meaning concerning the fitness. The following concepts are introduced in connection with the FCV: 1) the latent goodness-of-fit, 2) the basic latent goodness-of-fit, 3) the alienation of the realized goodness-of-fit from the latent goodness-of-fit, and 4) the basic alienation. A new view of the fitness is given on the basis of the above concepts. It is shown that the FCV can be used as a criterion for both identification and ex post facto evaluation. The relation between the FCV and Theil's inequality proportions is given. The FCV is applied to a real problem to show its usage and its effectiveness in ex post facto evaluation.
We give explicit analytic formulas for computing the L2 norm of a discrete-time generalised system whose rational transfer matrix function may be improper or polynomial. The norm is expressed in terms of solutions of ...
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This paper introduces a framework of tools which allow the design of distributed, potentially fault-tolerant, real-time control software. This framework takes a system specified in the controlengineering domain and t...
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This paper introduces a framework of tools which allow the design of distributed, potentially fault-tolerant, real-time control software. This framework takes a system specified in the controlengineering domain and translates this application-oriented representation into a software engineering representation. From this new representation, automatic code generation tools have been developed to create a complete, executable control system implementation.< >
Interconnections between AC power systems,power transmission with higher efficiency,and aggregation and delivery of power from offshore wind farms to different AC regions are among the main drivers for the development...
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Interconnections between AC power systems,power transmission with higher efficiency,and aggregation and delivery of power from offshore wind farms to different AC regions are among the main drivers for the development of HVDC *** grids can result in lower demand variability,higher flexibility,superior electricity market management,and higher economic *** is expected that isolated HVDC systems transition to an HVDC grid that overlays the existing AC *** a substantial development also results in a number of critical technical challenges related to system control,operation,and protection,which should be properly and accurately *** Special Issue focuses on the recent achievements and advancements in overcoming these *** papers for publications in this Special Issue fall into four major topics:devices,control,operation,and protection.
The development of on-line drug administration strategies in operating theatres represents a highly safety-critical situation. The usefulness of different levels of simulation prior to clinical trials has been shown i...
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The development of on-line drug administration strategies in operating theatres represents a highly safety-critical situation. The usefulness of different levels of simulation prior to clinical trials has been shown in previous studies in anaesthesia. Thus, in earlier work on pole-placement self-tuning for muscle relaxation, a dual computer real-time simulation was undertaker, subsequent to algorithm validation via off-line simulation. In the present work, supervised fuzzy rule-based control algorithms are being used. The control software was implemented on the actual machine to be used in theatre, while another computer acted as a real-rime patient simulator. it provides a fast design and simulation environment for safety-critical validation. The resultant validated controllers are now being used clinically.
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