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Integrated virtual commissioning an essential activity in the automation engineering process: From virtual commissioning to simulation supported engineering

Integrated virtual commissioning an essential activity in th...

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作者： Oppelt, Mathias Urbas, Leon Siemens AG Oestliche Rheinbrueckenstrasse 50 Karlsruhe76187 Germany Technische Universität Dresden Department of Process Control Systems Engineering Dresden01062 Germany

ISBN: (纸本)9781479940325

Production plants within manufacturing and process industries are becoming more and more complex systems. For a safe and demand sufficient production the automation system of a production plant is mission critical. Therefore the correct functioning and engineering of the automation system is essential. Nowadays the use of a virtual commissioning step before deploying the automation software on the real production plant is used more often. Within the virtual commissioning the automation software is tested against a virtual plant model, sufficient to check out the correct functioning of the automation system. Usually virtual commissioning is used as a step at the end of the automation engineering, as proposed by VDI 4499. Within this paper an integrated virtual commissioning is proposed, where the automation software is continuously tested against a virtual plant model during the overall engineering phase. The virtual plant is growing together with the automation software and thus enables simulation supported automation engineering. Benefits of the proposed workflow are that errors can be detected immediately after the implementation and the use of the virtual plant model could be extended to various stages of the engineering workflow. © 2014 IEEE.

关键词： Software testing

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Optimization of tool-path generation for material extrusion-based additive manufacturing technology

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Additive Manufacturing 2014年 1卷 32-47页

作者： Jin, Yu-an He, Yong Fu, Jian-zhong Gan, Wen-feng Lin, Zhi-wei The State Key Lab of Fluid Power Transmission and Control Systems Department of Mechanical Engineering Zhejiang University Hangzhou310027 China Zhejiang Province's Key Laboratory of 3D Printing Process and Equipment Department of Mechanical Engineering Zhejiang University Hangzhou310027 China

In this study, we propose a tool-path generation approach for material extrusion-based additive manufacturing (AM) that considers the machining efficiency and fabrication precision, which are inherent drawbacks of general AM techniques compared with conventional manufacturing methods. The proposed approach aims to tackle the generation of direction-parallel tool-paths for the interior filling of simple connected areas, which comprises three main steps: (1) determining the inclination of reference lines;(2) generating and grouping tool-path segments into individual sub-paths;and (3) linking sub-paths based on specific requirements. These three modules interact to affect the efficiency and precision of AM significantly. In order to find an optimal inclination, we first analyze the impacts on the fabrication efficiency and manufacturing accuracy with different inclinations. A comparatively accurate building time model is developed subsequently to obtain the optimal tool-path inclination, but without compromising the machining precision, based on the analysis of a geometrical accuracy model. The proposed approach employs different inclinations in distinct layers according to specific manufacturing scenarios and technological requirements. After determining the reference lines, the tool-path segments are selected and grouped based on some characteristics (e.g., the number of intersections between reference lines and boundaries) to make up individual sub-paths, which are then connected to a zigzag-shaped path with short line segment connections. In the module for sub-path linking, some strategies are introduced to decrease the number of useless tool-paths, i.e., uncut paths, which could jeopardize the manufacturing quality by frequently turning the print head on and off. In addition, parametric curves are used to link the final sub-paths to avoid deceleration/acceleration processes in the end/starting parts of the sub-paths. The proposed approach has been used in practice

关键词： 3D printers

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Analysis of the bullwhip effect in two parallel supply chains with interacting price-sensitive demands

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European Journal of Operational Research 2015年第3期243卷 815-825页

作者： Yungao Ma Nengmin Wang Zhengwen He Jizhou Lu Huigang Liang School of Management Xi'an Jiaotong University Xianning Road Xian Shaanxi 710049 No. 28 China The Key Lab of the Ministry of Education for Process Control & Efficiency Engineering Xianning Road Xian Shaanxi 710049 No. 28 China State Grid Energy Research Institute Changping District 102209 Beijing China Department of Management Information Systems College of Business East Carolina University Greenville NC 27858 USA

This paper offers insights into how the bullwhip effect in two parallel supply chains with interacting price-sensitive demands is affected in contrast to the situation of a single product in a serial supply chain. In particular, this research studies two parallel supply chains, each consisting of a manufacturer and a retailer, and the external demand for a single product depends on its price and the other's price in a situation in which each price follows a first-order autoregressive process. In this paper, we propose an analytical framework that incorporates two parallel supply chains, and we explore their interactions to determine the bullwhip effect. We identify the conditions under which the bullwhip effect is amplified or lessened with interacting price-sensitive demands relative to the situation without interaction.

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Modelling of the ultrasonic disintegration of activated sludge 19

Modelling of the ultrasonic disintegration of activated slud...

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19th IFAC World Congress on International Federation of Automatic control, IFAC 2014

作者： Lambert, N. Smets, I. Van Impe, J. Dewil, R. KU Leuven Department of Chemical Engineering Process and Environmental Technology Lab. Jan Pieter De Nayerlaan 5 Sint-Katelijne-WaverBE-2860 Belgium KU Leuven Department of Chemical Engineering Chemical and Biochemical Process Technology and Control Division W. de Croylaan 46 HeverleeBE-3001 Belgium

ISBN: (纸本)9783902823625

Ultrasonic treatment of waste activated sludge is one of the possibilities to reduce excess sludge production through the mechanism of sludge disintegration and cell lysis. In the past, several attempts have been made to model the process of solubilisation of the particulate volatile suspended solid part of the activated sludge (VSS) into soluble COD (sCOD). However, the focus of these models was predominantly on predicting an efficiency factor for the release of sCOD (Disintegration Degree, DDCOD) and provided no information on the release of nutrients and the instantaneous reduction of VSS. Moreover, often insufficient influential variables were included in the model equations, making the models only applicable on the training dataset of their own experimental research. This paper, therefore, seeks to build a simple model, which contains all influential input variables, that can predict not only the sCOD release but also the nutrients release (ortho-PO4-P and soluble Kjeldahl nitrogen) and VSS reduction simultaneously. Therefore, in first instance, a Principal Component Analysis (PCA) is carried out on the input and output data matrix of obtained experimental observations that will be used as training data. In this way, certain correlated input variables and independent output variables can be removed from the model, in order to increase its simplicity and predictive nature. Then, the model is built on the basis of Partial Least Squares Regression (PLS-R) and a part of the observations is used to validate the predictive strength of the model. © IFAC.

关键词： Activated sludge process

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Integrated Virtual Commissioning an essential Activity in the Automation engineering process: From virtual commissioning to simulation supported engineering

Integrated Virtual Commissioning an essential Activity in th...

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Annual Conference of the IEEE Industrial Electronics Society

作者： Mathias Oppelt Leon Urbas Siemens AG Technische Universitat Dresden Chair of Process Control Systems Engineering

ISBN: (纸本)9781479940318

关键词： Virtual commissioning Simulation Automation engineering Simulation supported testing

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Modular and active learning to support asynchronous learning in automation engineering

Modular and active learning to support asynchronous learning...

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International Conference on Information Technology Based Higher Education and Training, ITHET

作者： Annett Krause Leon Urbas Technische Universität Dresden Chair for Process Control Systems Engineering Dresden Germany

This paper discusses the application of modular and active learning concepts to courses in automation engineering for both vocational training and higher education. In the implemented concept, a course consists of several modular learning units that address different aspects of a single automation engineering process. To realize the complete cycle of activities every learning unit consists of a defined sequence of chapters, namely objectives, theoretical concepts, task definition, planning, and exemplary solution. The objective describes the contents so that the learner can decide if it matches his own objectives. Afterwards, theoretical concepts relevant to the objectives are presented to impart the basic knowledge. Now the definition of the tasks follows to realize the phase “recognition”. To combine the theory and the task the next part is planning to implement the phase “thinking”. Despite the fact that this phase is extremely important in the context of automation engineering, analysis of other course material and feedback from experienced trainers show that it is often skipped and is available only implicitly. By presenting one part of the solution the learner is led to a first solution. The presentation is done by structured step by step instructions so the learner can either follow every single item or only the main steps depending on his own level of knowledge. Eventually learners may evaluate a checklist to gain feedback which parts they managed and which ones they might want to repeat. After having finished the guided part successfully learners can switch to the exercises. Here they will get a task and need to plan their activities themselves. First evaluation results gained in a workshop with teachers support the hypothesis that the implemented concept is highly supportive.

关键词： Automation Programming Hardware Periodic structures Training process control

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Climate Change in Urban Versus Rural Areas

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Procedia engineering 2015年 119卷 1171-1180页

作者： Martina Zeleňáková Pavol Purcz Helena Hlavatá Peter Blišťan Technical University of Košice Faculty of Civil Engineering Institute of Environmental Engineering Vysokoškolská 4 042 00 Košice Slovakia Technical University of Košice Faculty of Civil Engineering Institute of Construction Technology and Management Vysokoškolská 4 042 00 Košice Slovakia Slovak Hydrometeorological Institute Ďumbierská 26 042 00 Košice Slovakia Technical University of Kosice Faculty of Mining Ecology Process Control and Geotechnology Institute of Geodesy Cartography and Geographical Information Systems Letná 9 042 00 Kosice Slovakia

The most important anthropogenic influences on climate are the emissions, changes in land use, such as urbanization aural areasnd agriculture. The urban environment has distinctive bioclimatical factors in relation to rural areas. The process of urbanization alters natural surface and atmospheric conditions. Urban areas are characteristic by increased rainwater surface runoff, increased temperatures and decreased evaporation. Exactly evaporation warms the rural surface more than the urban. The paper concerns on the impacts of urbanization that are evaluated by observations in cities with those in rural areas – not so populated and with smaller built areas. We use and asses the difference between trends in monthly average temperatures and trends in monthly precipitations in the cities and the corresponding trends in rural areas. For the trend analysis, the Mann-Kendall nonparametric test is used. Our results show differences in trends in villages and cities. Observed are increased trends in temperature and decreased trends in precipitation due to urban and land-use changes.

关键词： Precipitation temperature trends

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Assessment of Different PCM Storage Configurations in a 50 MW el CSP Plant with Screw Heat Exchangers in a Combined Sensible and Latent Storage – Simulation Results

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Energy Procedia 2015年 69卷 1078-1088页

作者： V. Zipf A. Neuhäuser C. Bachelier R. Leithner W. Platzer Dipl.-Ing. Project Leader Fraunhofer Institute for Solar Energy Systems Heidenhofstrasse 2 79110 Freiburg Germany Dr.-Ing Head of Group Thermal Processes and Systems Fraunhofer Institute for Solar Energy Systems Heidenhofstr. 2 79110 Freiburg Dipl.-Ing./Msc Applications Engineer Novatec Solar GmbH Herrenstrasse 33 76137 Karlsruhe Germany Prof. Dr. tech Institute of Energy and Process Systems Engineering TU Braunschweig Franz-Liszt-Strasse 35 38106 Braunschweig Germany Dr. Director Division Solar Thermal and Optics Fraunhofer Institutefor Solar Energy SystemsHeidenhofstr. 2 79110 Freiburg Germany

Effective and economic storage solutions have an important role to enable Solar Thermal Electricity plants (STE) to generate dispatchable power. A thermal storage can increase the value of STE by providing firm electricity in times of peak load or ancillary services. Latent storages are suited optimally for direct steam generating STE systems: due to the isothermal behavior of the phase change materials (PCM) during melting /crystallization, exergy losses during storage charging/discharging are minimized. Up to now latent heat storages are, due to technical and economic issues, not used commercially in STE systems. The PCM have a very low heat conductivity – therefore a sophisticated heat exchanger design is needed to build such storages with sufficient charging/discharging power. An innovative storage concept, uses a screw heat exchanger to transport the PCM from a cold to a hot tank or vice versa during phase change. This concept separates heat exchange and storage *** concepts do not have this ability. In annual yield calculations the use of this heat exchanger as part of a thermal storage in a 50 MW el direct steam generating solar thermal power plant has been assessed. After setting up of a cost structure, the respective levelised cost of electricity (LCOE) have been used as comparison criterion for two storage systems with different designs. It can be shown, that a storage system with three storage tanks yields lower LCOE than one with two storage tanks. There is further potential for cost reductions, such as the optimization of the heat exchanger area and the temperature difference between the heat transfer fluid and the PCM.

关键词： latent heat storage screw heat exchanger solarthermal power plant levelised cost of electricity phase change material concentrated solar power direct steam generation

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Separable model predictive control via alternating direction method of multipliers for large-scale systems 19

Separable model predictive control via alternating direction...

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19th IFAC World Congress on International Federation of Automatic control, IFAC 2014

作者： Lu, Liang Division of Automatic Control Department of Electrical Engineering Linköping University LinköpingSE-581 83 Sweden State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang China

ISBN: (纸本)9783902823625

In this paper, an alternating direction method of multipliers (ADMM) based realtime model predictive control (MPC) algorithm is presented. With the use of indicator function and by introducing extra consensus constraints, the constrained MPC problem can be formulated as a separable MPC problem, which can be computed very efficiently by projected gradient descent ADMM update steps and Riccati recursions. The sequence of the objective value of this constrained real-time ADMM-type MPC algorithm satisfies a linear convergence rate. The procedure is also extended to distributed systems with constraints, in which the variables of each subsystems communicate with their neighbors and update in the Gauss-Seidel way. An illustrative example shows the effectiveness of this approach. © IFAC.

关键词： Model predictive control

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Triangular Fuzzy Number Representation of Relations in Fuzzy Cognitive Maps

Triangular Fuzzy Number Representation of Relations in Fuzzy...

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IEEE International Conference on Fuzzy systems

作者： Engin Yesil M. Furkan Dodurka Leon Urbas Control and Automation Engineering Department Istanbul Technical University Istanbul Turkey Chair of Process Control Systems Engineering Technology University of Dresden Germany

In this paper, the conventional Fuzzy Cognitive Maps (FCMs), which has already achieved success in many fields, are extended by using triangular fuzzy numbers (TFNs). The advantage of FCMs is that they are relatively easy to construct and parameterize and are capable of handling the full range of system feedback structure, including density-dependent effects. However, it is a well-known fact that there are some limitations inherent in FCM, such as lack of adequate capability to handle uncertain information and lack of enough ability to aggregate the information from different sources. Triangular fuzzy numbers which are represented by a triplet has the capacity to represent the uncertain relations between the concepts. In this context, the weight matrix representing the causal relations are enhanced to a fuzzy weight matrix that has TFNs as element. As a result of this improvement, the dynamic reasoning algorithm of the conventional FCM is improved for the use of the proposed novel FCM. The proposed FCM is presented via four simulations and the results are discussed. The results of the simulation study shows how easily the uncertain information can be represented and interpreted by the proposed FCM design methodology.

关键词： Uncertainty Vectors Cognition Fuzzy sets Pragmatics Fuzzy cognitive maps Modeling

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