Novel analysis and modelling methodologies applied to pultrusion and other processes

Often a manufacturing process may be a bottleneck or critical to a business. This thesis focuses on the analysis and modelling of such processest, to both better understand them, and to support the enhancement of quality or output capability of the process. The main thrusts of this thesis therefore are: To model inter-process physics, inter-relationships, and complex processes in a manner that enables re-exploitation, re-interpretation and reuse of this knowledge and generic elements e.g. using Object Oriented (00) & Qualitative Modelling (QM) techniques. This involves the development of superior process models to capture process complexity and reuse any generic elements; To demonstrate advanced modelling and simulation techniques (e.g. Artificial Neural Networks(ANN), Rule-Based-Systems (RBS), and statistical modelling) on a number of complex manufacturing case studies; To gain a better understanding of the physics and process inter-relationships exhibited in a number of complex manufacturing processes (e.g. pultrusion, bioprocess, and logistics) using analysis and modelling. To these ends, both a novel Object Oriented Qualitative (Problem) Analysis (OOQA) methodology, and a novel Artificial Neural Network Process Modelling (ANNPM) methodology were developed and applied to a number of complex manufacturing case studies- thermoset and thermoplastic pultrusion, bioprocess reactor, and a logistics supply chain. It has been shown that these methodologies and the models developed support capture of complex process inter-relationships, enable reuse of generic elements, support effective variable selection for ANN models, and perform well as a predictor of process properties. In particular the ANN pultrusion models, using laboratory data from IKV, Aachen and Pera, Melton Mowbray, predicted product properties very well

Model based fault diagnosis for hybrid systems : application on chemical processes

The complexity and the size of the industrial chemical processes induce the monitoring of a growing number of process variables. Their knowledge is generally based on the measurements of system variables and on the physico-chemical models of the process. Nevertheless, this information is imprecise because of process and measurement noise. So the research ways aim at developing new and more powerful techniques for the detection of process fault. In this work, we present a method for the fault detection based on the comparison between the real system and the reference model evolution generated by the extended Kalman filter. The reference model is simulated by the dynamic hybrid simulator, PrODHyS. It is a general object-oriented environment which provides common and reusable components designed for the development and the management of dynamic simulation of industrial systems. The use of this method is illustrated through a didactic example relating to the field of Chemical Process System Engineering

Dynamic state reconciliation and model-based fault detection for chemical processes

In this paper, we present a method for the fault detection based on the residual generation. The main idea is to reconstruct the outputs of the system from the measurements using the extended Kalman filter. The estimations are compared to the values of the reference model and so, deviations are interpreted as possible faults. The reference model is simulated by the dynamic hybrid simulator, PrODHyS. The use of this method is illustrated through an application in the field of chemical processe

Ecodesign of Batch Processes: Optimal Design Strategies for Economic and Ecological Bioprocesses

This work deals with the multicriteria cost-environment design of multiproduct batch plants, where the design variables are the equipment item sizes as well as the operating conditions. The case study is a multiproduct batch plant for the production of four recombinant proteins. Given the important combinatorial aspect of the problem, the approach used consists in coupling a stochastic algorithm, indeed a Genetic Algorithm (GA) with a Discrete Event Simulator (DES). To take into account the conflicting situations that may be encountered at the earliest stage of batch plant design, i.e. compromise situations between cost and environmental consideration, a Multicriteria Genetic Algorithm (MUGA) was developed with a Pareto optimal ranking method. The results show how the methodology can be used to find a range of trade-off solutions for optimizing batch plant design

Dynamic hybrid simulation of batch processes driven by a scheduling module

Simulation is now a CAPE tool widely used by practicing engineers for process design and control. In particular, it allows various offline analyses to improve system performance such as productivity, energy efficiency, waste reduction, etc. In this framework, we have developed the dynamic hybrid simulation environment PrODHyS whose particularity is to provide general and reusable object-oriented components dedicated to the modeling of devices and operations found in chemical processes. Unlike continuous processes, the dynamic simulation of batch processes requires the execution of control recipes to achieve a set of production orders. For these reasons, PrODHyS is coupled to a scheduling module (ProSched) based on a MILP mathematical model in order to initialize various operational parameters and to ensure a proper completion of the simulation. This paper focuses on the procedure used to generate the simulation model corresponding to the realization of a scenario described through a particular scheduling

Plan recognition for space telerobotics

Current research on space telerobots has largely focused on two problem areas: executing remotely controlled actions (the tele part of telerobotics) or planning to execute them (the robot part). This work has largely ignored one of the key aspects of telerobots: the interaction between the machine and its operator. For this interaction to be felicitous, the machine must successfully understand what the operator is trying to accomplish with particular remote-controlled actions. Only with the understanding of the operator's purpose for performing these actions can the robot intelligently assist the operator, perhaps by warning of possible errors or taking over part of the task. There is a need for such an understanding in the telerobotics domain and an intelligent interface being developed in the chemical process design domain addresses the same issues

Redesign Support Framework for Complex Technical Processes

Els processos industrials requereixen avaluacions periòdiques per a verificar la seva correcta operació en termes tècnics i econòmics. Aquestes avaluacions són necessàries a causa de els canvis en els mercats i en la legislació ambiental i de seguretat. Per a satisfer aquestes demandes és necessari investigar les alternatives dels processos que permetin l'ús òptim dels recursos existents amb la mínima inversió econòmica possible. Aquesta tasca es coneix com redisseny, que és un procediment per a determinar possibles canvis en un procés existent per a millorar-lo pel en alguna mètrica, tal com econòmica, ambiental, de seguretat, etc. En aquesta tesi es proposa un marc d'ajuda al redisseny per a processos tècnics. Aquest marc fa ús d'una representació jeràrquica de models múltiples del procés que es re dissenyarà en conjunció amb un motor que raonament basat en casos per a ajudar a decidir quins elements del procés han de ser modificats. El marc consisteix en quatre etapes principals: adquisició de la descripció del disseny, identificació de candidats, generació d'alternatives, i adaptació i avaluació d'alternatives.El procés original es modela jeràrquicament emprant conceptes de mitjans-fins i parts-tot. Així el coneixement sobre el comportament, l'estructura, la funció i l'objectiu de cadascuna de les parts del procés es genera i s'emmagatzema automàticament. Donat les noves especificacions o requisits que el procés ha de satisfer, el sistema troba les parts del procés que ha de ser redissenyades. S'utilitza una llibreria de casos per a obtenir seccions alternatives del procés que es puguin adaptar per a substituir parts del procés original. Per tant, el marc proposat permet modelar el procés, identificar els components de procés viables a redissenyar, obtenir components alternatius i finalment adaptar aquests components alternatius en el procés original. Aquest procediment es pot veure com activitat d'enginyeria inversa on es generen models abstractes en diversos nivells a partir d'una descripció detallada d'un procés existent per a reduir la seva complexitat. El marc ha estat implementat i provat en el domini d'Enginyeria Química.Los procesos industriales requieren evaluaciones periódicas para verificar su correcta operación en términos técnicos y económicos. Estas evaluaciones son necesarias debido a los cambios en los mercados y en la legislación ambiental y de seguridad. Para satisfacer estas demandas es necesario investigar las alternativas de los procesos que permitan el uso óptimo de los recursos existentes con la mínima inversión económica posible. Esta tarea se conoce como rediseño, que es un procedimiento para determinar posibles cambios en un proceso existente para mejorarlo con respecto a alguna métrica, tal como económica, ambiental, de seguridad, etc.En esta tesis se propone un marco de ayuda al rediseño para procesos técnicos. Este marco emplea una representación jerárquica de modelos múltiples del proceso que se rediseñará en conjunción con un motor que razonamiento basado en casos para ayudar a decidir qué elementos del proceso deben ser modificados. El marco consiste en cuatro etapas principales: adquisición de la descripción del diseño, identificación de candidatos, generación de alternativas, y adaptación y evaluación de alternativas. El proceso original se modela jerárquicamente empleando conceptos de medios-fines y partes-todo. Así el conocimiento sobre el comportamiento, la estructura, la función y el objetivo de cada una de las parte del proceso se genera y se almacena automáticamente. Dado las nuevas especificaciones o requisitos que el proceso debe satisfacer, el sistema encuentra las partes del proceso que debe ser rediseñadas. Se utiliza una librería de casos para obtener secciones alternativas del proceso que se puedan adaptar para sustituir partes del proceso original. Por lo tanto, el marco propuesto permite modelar el proceso, identificar los componentes de proceso viables a rediseñar, obtener componentes alternativos y finalmente adaptar estos componentes alternativos en el proceso original. Este procedimiento se puede ver como actividad de ingeniería inversa donde se generan modelos abstractos en diversos niveles a partir de una descripción detallada de un proceso existente para reducir su complejidad. El marco ha sido implementado y probado en el dominio de Ingeniería Química.Industrial processes require periodic evaluations to verify their correct operation, both in technical and economical terms. These evaluations are necessary due to changes in the markets, and in safety and environmental legislation. In order to satisfy these demands it is necessary to investigate process alternatives that allow the optimal use of existing resources with the minimum possible investment. This task is known as redesign, which is a procedure to determine possible changes to an existing process in order to improve it with respect to some metric, such as economical, environmental, safety, etc.A redesign support framework for technical processes is proposed in this thesis. This framework employs a multiple-model hierarchical representation of the process to be redesigned together with a case-based reasoning engine that helps to decide which elements of the process should be modified. The framework consists of four main stages: acquisition of the design description, identification of candidates, generation of alternatives, and adaptation and evaluation of alternatives.The original process is modelled hierarchically exploiting means-end and part-whole concepts, and thus knowledge about the behaviour, structure, function and intention of each part of the process is automatically generated and stored. Given the new specifications or requirements that the process must fulfil, the system finds the parts of the process which must be redesigned and a case library is used to obtain alternative process sections which can be adapted to substitute parts of the original process. Therefore, the proposed framework allows to model the process, to identify process components suitable for redesign, to obtain alternative components, and finally, to adapt these components into the original process. This procedure can be seen as a reverse engineering activity where abstract models at different levels are generated from a detailed description of an existing process to reduce its complexity. The framework has been implemented and tested on the Chemical Engineering domain.Postprint (published version

Model-based groupware solution for distributed real-time collaborative 4D planning via teamwork

Construction planning plays a fundamental role in construction project management that requires team working among planners from a diverse range of disciplines and in geographically dispersed working situations. Model-based four-dimensional (4D) computer-aided design (CAD) groupware, though considered a possible approach to supporting collaborative planning, is still short of effective collaborative mechanisms for teamwork due to methodological, technological and social challenges. Targeting this problem, this paper proposes a model-based groupware solution to enable a group of multidisciplinary planners to perform real-time collaborative 4D planning across the Internet. In the light of the interactive definition method, and its computer-supported collaborative work (CSCW) design analysis, the paper discusses the realization of interactive collaborative mechanisms from software architecture, application mode, and data exchange protocol. These mechanisms have been integrated into a groupware solution, which was validated by a planning team in a truly geographically dispersed condition. Analysis of the validation results revealed that the proposed solution is feasible for real-time collaborative 4D planning to gain a robust construction plan through collaborative teamwork. The realization of this solution triggers further considerations about its enhancement for wider groupware applications

Computer aids for process model-building

Imperial Users onl