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This paper proposes the design of an observer-based control law for a continuous stirred tank reactor with recycle time-delay. Recent results on differential geometry for nonlinear time-delay systems are used. The many performed simulations show the high performance of the proposed control law.

A modern paper machine is a very complicated piece of machinery and full of automation. Paper machine specialists can be in different locations around the world and that is why efficient communication networks are needed to transfer technical information between them. This paper specifies the terminology to cope with information transfer in a paper machine project. The information transfer techniques and system architecture during different generations of the paper mill automation systems are described briefly. Limitations of different generations of remote services are also discussed. The need for different communication networks is specified as well as the need for changes in management of cooperation between different partners in paper industry. The use of Internet technology is described in the communication systems. Copyright © 2002 IFAC

This paper presents a control design approach for robust sheet control in a printer paper path. The overall design question is formulated in terms of a hierarchical control set-up with a low level motor control part and a high level sheet control part. The sheet dynamics, subject to disturbances and parameter uncertainties, are captured in the piecewise linear modeling formalism. Based on this model, the control design yields robust sheet feedback controllers and a closed-loop system capable of rejecting disturbances up to a prescribed level. The effectiveness of the control design is shown on an experimental paper path setup.

Sheet-break is a long standing problem in pulp and paper industry. If advance warnings can be issued ahead of time, corrective actions may be taken to prevent some of the breaks. In this paper, we describe the development and implementation of an online monitoring scheme. A data based approach was taken in this analysis. PCA was used to model the process, and a combined index based on the Hotelling's T 2 and Q-statistics was developed as a sheet-break predictor. As the process is subject to external disturbances, grade changes, and frequent interruptions, preprocessing of the data played an important role in getting consistent results. We used several novel techniques for data selection, scaling and modelling. The models were validated using a large validation data set with known fault condition.

This study focuses on the applications of web based performance and knowledge support systems in the paper industry. Two different systems – a generic KnowPap learning environment and a customized electronic performance support system (EPSS) were evaluated. The results indicate a very limited usability of generic systems for operational and knowledge support. The customized KnowFine system was found very useful to support the operations and maintenance. In future this kind of customized systems will be integrated to process control and information management systems. Optimally the lice-cycle of these systems follows the life-cycle of the plant.

Enterprise-control system integration between business systems, manufacturing execution systems and shop-floor process-control systems remains a key issue for facilitating the deployment of plant-wide information-control systems for practical e-Business-to-Manufacturing industry-led issues. This achievement of the Integration-in-Manufacturing paradigm based on centralized/distributed hardware/software automation architectures is shifting by the Intelligence-in-Manufacturing paradigm addressed by the IMS industry-led R&D initiative in order to define and to experiment the next generation of manufacturing systems capable to cope with the high degree of complexity of meeting agility over flexibility and reactivity in customized manufacturing. This survey paper of the TC 5.1 summarizes these key problems, trends and accomplishments for manufacturing plant control before to emphasize for practical purposes some rationales and forecasts in deploying automation over networks, HMS and its related agent-based technology, as well as in applying formal methods to ensure dependable manufacturing.

This paper is aimed at exploring the understanding of the changes that face the lower levels of the supply chains as business moves from a global market into service with multiple highly changeable products and offerings, demanding interoperability across skills, customers and suppliers.

Paper manufacturing involves the sequential removal of water from pulp by means of gravity, vacuum dewatering, mechanical pressing and thermal drying. This research proposes a new control topology for moisture content using surrogate measurements to infer in-process moisture content, and the pressure settings in the vacuum dewatering section as actuators. The new topology has the potential to overcome the performance, robustness and energy efficiency limitations that the current process control topology has, due to a long dead-time and excessive use of the dryers. A preemptive control law was previously proposed for the new topology to decouple the upstream disturbances from propagating downstream in the process. In this paper, we develop an adaptive version of this pre-emptive controller to alleviate the need to know the dewatering coefficients precisely. The adaptive control problem has the interesting aspects that the unknown parameters are nonlinearly embedded in the error dynamics, and there is a time delay before the error in the estimated parameters can be observed.

This presentation is devoted to the history of the creation and the contents of not very well-known paper by A.I. Lurie "Certain Problems of Self-synchronization" published in 1970. By this time, some investigations of self-synchronization of unbalanced rotors and pendulum clocks had been carried out mainly by Lurie's pupils. They used the techniques by Poincare, Lyapunov, and asymptotic methods in their investigations. To study this problem A.I. Lurie applied the Hamilton variation principle in conjunction with the method of small parameter and Galerkin's method. Main results were obtained by Lurie in very laconic and elegant form very characteristic for him. This presentation emphasizes the role of Lurie's paper to understand the regularities of frequency self-synchronization and for further development of its theory.

In this paper the dynamics of a roll-nip system in paper finishing units in the case of polymer covered roll is studied. The delay effect which provides an important additional effect on roll deformation and vibration of the system has been taken into account. The dynamical behavior of this system has been analysed in frequency domain and time domain.

An analytical model of moving paper in a printing station is proposed. Performance of basic PI control is discussed, and noninteracting control of machine speed and paper stress is analyzed. Theoretical results are illustrated with simulation data.

In this overview, we present an outline of the selected papers in these Proceeding on SWIIS 2000. Plenary papers IPL1, KNP2, SP1, and SSP are outlined first, and then all other contributions. Contributed papers are grouped according the respective topics in 7 chapters on: general aggression and security modelling; game theory and general systems approaches; fuzzy information, fuzzy systems and qualitative modelling; issues of ethics, fairness and justice in SWIIS problems; hybrid solution concepts and modelling techniques; case studies on Kosovo crisis; and business management based approaches. Due to the topic of special interest, the second chapter begins with the special survey paper. Individual chapters encompass two to four contributed papers.

This paper presents a new approach for the cross-directional basis weight control on paper machines. The multivariable control system with high-dimension is discoupled into several subsystems by introducing a new constraint on control variables to satisfy the computation and capability limitation of existing on-line control system. A block discoupling algorithm is developed, and a parallel control strategy is proposed to implement the control algorithm. Based on the strategy, a multiprocessors system is designed to realize the simulation. Simulation results show that the computational time can be significantly decreased and the real-time performance can be improved.

This paper presents a novel approach for the change detection of the output probability density functions for dynamic stochastic systems. Using the B-splines neural network, the measured probability density functions of the system output are represented by a set of weights which are functions of the control inputs to the system. This leads to a unique expression of the dynamic characteristics of the output probability density functions for the system. An observer based fault detection is developed which detects any unexpected changes of the parameters in the dynamic part of the system. An application to the detection of unexpected changes of particle size in paper-making is included to demonstrate the use of the proposed algorithm and desired results have been obtained.

In today's increasingly competitive markets, leading engineering organizations need to capitalize on every available opportunity to increase the quality oftheir products while reducing the length of the development cycle and manufacturing costs. This paper presents an integral approach for the reliability validation process of a product in the automotive industry. The stress/strength concepts are applied to estimate and validate the product reliability in which case both stress and strength are random occurring parameters within the reliability validation process. The simulation approach using vinual prototypes is presented as well.

Present evolution of manufacturing systems is characterized by a progressive increase of the importance of knowledge-driven work in industrial plants of very large dimension. As the system complexity and the intelligent agents number grow, the system response uncertainty seems to grow also: this suggests to have greater attention to the agents intelligence. This paper first aims to verify if the increasing complexity of actual work systems is going to allow a greater and greater autonomy to individual agents. Then, taking into account that final scope of an enterprise is profit, a positive relation between global system efficiency and local agents autonomy is proved.

This paper deals with the characterization of all the optimal solutions of the twomachine flowshop scheduling problem with maximum completion time criterion. A model is proposed, and maximal sequences are defined. A polynomial time algorithm is presented to determine the first maximal sequence and a tree-search algorithm is proposed to determine all the maximal sequences.

A new approach for estimation and modeling of Cross-Directional (CD) basis weight on paper machines is proposed based on multiresolution analysis theory. Orthogonal basis wavelet functions are used to represent CD basis weight profiles at different resolutions. By selecting a suitable threshold resolution, the controllable and uncontrollable parts of the profile can be separated. A novel response model of the CD profile to actuators is established in the wavelet transform(WT) domain. Simulation results show that a significant reduction of the dimension of system can be achieved by modeling in the WT domain.

This paper addresses the problem of estimating the effective actuator centre locations in a paper machine whilst the process is operating in closed loop. A reduced order estimator employing a Radial Basis Function Network is described, where the basis functions in the hidden layer are defined using Discrete Chebyshev Polynomials. The problem is considered as a nonlinear optimisation problem and solved online using a recursive prediction error method.