| 1. |
- Asghar, Adeel, et al.
(författare)
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Automatic Regression Testing of Simulation Models and Concept for Simulation of Connected FMUs in PySimulator
- 2015
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Ingår i: Proceedings of the 11th International Modelica Conference. - Linköping : Linköping University Electronic Press. - 9789176859551 ; , s. 671-679
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Konferensbidrag (refereegranskat)abstract
- The Modelica and FMI tool ecosystem is growing each year with new tools and methods becoming available. The open Modelica standard promises portability but it is important to ensure that a certain model behaves the same in different Modelica tools or in a different version of the same tool. It is also very important (for model evolution) to check that a new version of the same model produces comparable results. Finally, it is desirable to verify that a model exported in FMU form from a Modelica tool gives exactly the same results as the original model. This paper presents a framework for automatic regression testing as part of PySimulator which provides an efficient and concise way of testing if a model or a range of models behaves in the same way in several tools or versions of a tool by checking that the results produced are essentially identical. The FMI standard has been adopted by many tool vendors and is growing in popularity each year. This paper proposes a concept for building and simulating a system made from connected FMUs generated by different tools. The FMUs for Co-Simulation can be connected together using a GUI. The system model built graphically in this way can be saved for later use or simulated directly inside PySimulator. Active development is going on to support simulation of connected FMUs for Model Exchange.
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| 2. |
- Asghar, Adeel, et al.
(författare)
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Efficient Debugging of Large Algorithmic Modelica Applications
- 2012
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Konferensbidrag (refereegranskat)abstract
- Modelica models often contain functions with algorithmic code. The fraction of algorithmiccode is increasing in Modelica models since Modelica, in addition to equation-based modeling, is also used for embedded system control code and symbolic model transformations in compilers using the MetaModelica language extension. For these reasons, debugging of algorithmic Modelica code is becoming increasingly relevant.Our earlier work in debuggers for the algorithmic subset of Modelica used trace-based techniques. These have the advantages of being very portable, but turned out to have too much overhead for very large applications.The new debugger is the first Modelica debugger that can operate without trace information. Instead it communicates with a low-level C-language symbolic debugger, the Gnu debugger GDB, to directly extract information from a running executable, set and remove breakpoints, etc. This is made possible by the new bootstrapped OpenModelica compiler which keeps track of a detailed mapping from the high level Modelica code down to the generated C code compiled to machine code.The debugger is operational, supports browsing of both standard Modelica data structures and tree/list data structures, and operates efficiently on large applications such as the OpenModelica compiler with more than 100 000 lines of code.
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| 3. |
- Asghar, Syed Adeel, et al.
(författare)
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An Open Source Modelica Graphic Editor Integrated with Electronic Notebooks and Interactive Simulation
- 2011
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Ingår i: Proceedings of the 8th International Modelica Conference, March 20th-22nd, Technical Univeristy, Dresden, Germany. - Linköping : Linköping University Electronic Press. - 9789173930963 ; , s. 739-747
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Konferensbidrag (refereegranskat)abstract
- This paper describes the first open source Modelica graphic editor which is integrated with interactive electronic notebooks and online interactive simulation. The work is motivated by the need for easy-to-use graphic editing of Modelica models using OpenModelica, as well as needs in teaching where the student should be able to interactively modify and simulate models in an electronic book. Models can be both textual and graphical. The interactive online simulation makes the simulation respond in real-time to model changes, which is useful in a number of contexts including immediate feedback to students.
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| 4. |
- Braun, Robert, 1984-, et al.
(författare)
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An Open-Source Framework for Efficient Co-simulation of Fluid Power Systems
- 2017
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Ingår i: Proceedings of 15th Scandinavian International Conference on Fluid Power, SICFP’17. - Linköping : Linköping University Electronic Press. - 9789176853696 ; , s. 393-400
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Konferensbidrag (refereegranskat)abstract
- Simulation of fluid power systems typically requires models from multiple disciplines.Achieving accurate load dynamics for a system with complex geometry, for example, mayrequire both a 1D model of the hydraulic circuit and a 3D multi-body model. However, mostsimulation tools are limited to a single discipline. A solution to these kinds of problems isco-simulation, where different tools are coupled and simulated together. Co-simulation canprovide increased accuracy, improved modularity and facilitated collaboration between dif-ferent organizations. Unfortunately, tool coupling typically requires tedious and error-pronemanual work. It may also introduce numerical problems. For these reasons, co-simulation isoften avoided as long as possible. These problems have been addressed by the developmentof an open-source framework for asynchronous co-simulation. Simulation tools can be inter-connected through a stand-alone master simulation tool. An extensive range of tools is alsosupported via the Functional Mockup Interface standard. A graphical user interface has beenimplemented in the OpenModelica Connection Editor. System models can be created andedited from both a schematic view and a 3D view. Numerical robustness is enforced by theuse of transmission line modelling. A minimalistic programming interface consisting of onlytwo functions is used. An example model consisting of a hydraulic crane with two arms, twoactuators and a hanging load is used to verify the framework. The composite model consistsof nine multi-body models, one hydraulic system model and a controller. It is shown thatmodels from various simulation tools can be replaced with a minimal amount of user input.
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| 5. |
- Fritzson, Peter, 1952-, et al.
(författare)
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MetaModelica – A Symbolic-Numeric Modelica Language and Comparison to Julia
- 2019
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Ingår i: Proceedings of the 13th International Modelica Conference, Regensburg, Germany, March 4–6, 2019. - Linköping : Linköing University Electronic Press. - 9789176851227
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Konferensbidrag (refereegranskat)abstract
- The need for integrating system modeling with advanced tool capabilities is becoming increasingly pronounced. For example, a set of simulation experiments may give rise to new data that are used to systematically construct a series of new models, e.g. for further simulation and design optimization. Such combined symbolic-numeric capabilities have been pioneered by dynamically typed interpreted languages such as Lisp and Mathematica. Such capabilities are also relevant for advanced modeling and simulation applications but lacking in the standard Modelica language. Therefore, this is a topic of long-running design discussions in the Modelica Design group. One contribution in this direction is MetaModelica, that has been developed to extend Modelica with symbolic operations and advanced data structures, while preserving safe engineering practices through static type checking and a compilation-based efficient implementation. Another recent effort is Modia, implemented using the Julia macro mechanism, making it dynamically typed but also adding new capabilities. The Julia language has appeared rather recently and has expanded into a large and fast-growing ecosystem. It is dynamically typed, provides both symbolic and numeric operations, advanced data structures, and has a just-intime compilation-based efficient implementation. Despite independent developments there are surprisingly many similarities between Julia and MetaModelica. This paper presents MetaModelica and its environment as a large case study, together with a short comparison to Julia. Since Julia may be important for the future Modelica, some integration options between Modelica tools and Julia are also discussed, including a possible approach for implementing MetaModelica (and OpenModelica) in Julia.
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| 6. |
- Fritzson, Peter, 1952-, et al.
(författare)
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The OpenModelica Integrated Environment for Modeling, Simulation, and Model-Based Development
- 2020
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Ingår i: Modeling, Identification and Control. - Kristiansand, Norway : Norsk Forening for Automatisering. - 0332-7353 .- 1890-1328. ; 41:4, s. 241-295
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Tidskriftsartikel (refereegranskat)abstract
- OpenModelica is a unique large-scale integrated open-source Modelica- and FMI-based modeling, simulation, optimization, model-based analysis and development environment. Moreover, the OpenModelica environment provides a number of facilities such as debugging; optimization; visualization and 3D animation; web-based model editing and simulation; scripting from Modelica, Python, Julia, and Matlab; efficient simulation and co-simulation of FMI-based models; compilation for embedded systems; Modelica-UML integration; requirement verification; and generation of parallel code for multi-core architectures. The environment is based on the equation-based object-oriented Modelica language and currently uses the MetaModelica extended version of Modelica for its model compiler implementation. This overview paper gives an up-to-date description of the capabilities of the system, short overviews of used open source symbolic and numeric algorithms with pointers to published literature, tool integration aspects, some lessons learned, and the main vision behind its development.
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| 7. |
- Mengist, Alachew, et al.
(författare)
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An Open-Source Graphical Composite Modeling Editor and Simulation Tool Based on FMI and TLM Co-Simulation
- 2015
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Ingår i: Proceedings of the 11th International Modelica Conference. - Linköping : Linköping University Electronic Press. - 9789176859551 ; , s. 181-188
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Konferensbidrag (refereegranskat)abstract
- A common situation in industry is that a system model (here a composite model) is composed of several sub-models which may have been developed using different tools. FMI is one important technology for exporting/importing models between tools and/or connecting them via co-simulation. TLM based modeling and co-simulation is another important technique for modeling, connecting, and simulation of especially mechanical systems, which is simple, numerically stable, and efficient. A number of tool-specific simulation models, such as Modelica models, SimuLink models, Adams models, BEAST models, etc., have successfully been connected and simulated using TLM based co-simulation. However, previously there was no general open source tool for creation, graphic editing, and simulation of composite models connected via FMI or TLM based co-simulation. In this paper we present a graphical composite model editor based on OpenModelica which is integrated with the OpenModelica and the SKF TLM co-simulation frameworks to support both FMI and TLM based composite model editing and simulation. The editor supports creating, viewing and editing a composite model both in textual and graphical representation. The system supports simulation of composite models consisting of sub-models created using different tools.
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| 8. |
- Nazir, Uzma, et al.
(författare)
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Biferrocenyl Schiff bases as efficient corrosion inhibitors for an aluminium alloy in HCl solution : a combined experimental and theoretical study
- 2020
-
Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 10:13, s. 7585-7599
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Tidskriftsartikel (refereegranskat)abstract
- The corrosion inhibitive capabilities of some ferrocene-based Schiff bases on aluminium alloy AA2219-T6 in acidic medium were investigated using Tafel polarization, electrochemical impedance spectroscopy (EIS), weight loss measurement, FT-IR spectroscopy and scanning electron microscopic (SEM) techniques. The influence of molecular configuration on the corrosion inhibition behavior has been explored by quantum chemical calculation. Ferrocenyl Schiff bases 4,4′-((((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcua), 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-methoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcub) and 4,4′-((((ethane-1,2-diylbis(oxy))bis(2-ethoxy-1,4-phenylene))bis(methaneylylidene))bis(azaneylylidene))bisferrocene (Fcuc) have been synthesized and characterized by FT-IR, 1H and 13C NMR spectroscopic studies. These compounds showed a substantial corrosion inhibition against aluminium alloy in 0.1 M of HCl at 298 K. Fcub and Fcuc showed better anticorrosion efficiency as compared with Fcua due to the electron donating methoxy and ethoxy group substitutions, respectively. Polarization curves also indicated that the studied biferrocenyl Schiff bases were mixed type anticorrosive materials. The inhibition of the aluminium alloy surface by biferrocenyl Schiff bases was evidenced through scanning electron microscopy (SEM) studies. Semi-empirical quantum mechanical studies revealed a correlation between corrosion inhibition efficiency and structural functionalities.
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| 9. |
- Pop, Adrian, et al.
(författare)
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Integrated Debugging of Modelica Models
- 2014
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Ingår i: Modeling, Identification and Control. - : Norwegian Society of Automatic Control. - 1890-1328. ; 35:2, s. 93-107
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Tidskriftsartikel (refereegranskat)abstract
- The high abstraction level of equation-based object-oriented (EOO) languages such as Modelica has the drawback that programming and modeling errors are often hard to find. In this paper we present integrated static and dynamic debugging methods for Modelica models and a debugger prototype that addresses several of those problems. The goal is an integrated debugging framework that combines classical debugging techniques with special techniques for equation-based languages partly based on graph visualization and interaction. To our knowledge, this is the first Modelica debugger that supports both equation-based transformational and algorithmic code debugging in an integrated fashion.
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| 10. |
- Sjölund, Martin, 1984-, et al.
(författare)
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Integrated Debugging of Equation-Based Models
- 2014
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Ingår i: Proceedings of the 10th International Modelica Conference. - : Linköping University Electronic Press. - 9789175193809 ; , s. 195-204
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Konferensbidrag (refereegranskat)abstract
- The high abstraction level of equation-based object-oriented languages (EOO) such as Modelica has the drawback that programming and modeling errors are often hard to find. In this paper we present the first integrated debugger for equation-based languages like Modelica; which can combine static and dynamic methods for run-time debugging of equation-based Modelica models during simulations. This builds on and extends previous results from a transformational static equation debugger and a dynamic debugger for the algorithmic subset of Modelica.
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