Modeling and Simulation of Hydraulic and Pneumatic Systems in Dymola/Modelica by Means of Bond Graphs

Description

Dymola is the most advanced software on the market today for the modeling and simulation of physical systems. Dymola ist fully object-oriented, and offers the user a graphical interface that permits modeling even highly complex systems in such a way as to make the resulting models easily maintainable [1].

To maximize the maintainability of the models, it is useful to graphically model down as far as possible, i.e., to postpone the transition from the graphical to equation-based models for as long as possible. Bond graphs are particularly well suited for the modeling of complex physical processes, because they represent the most primitive graphical modeling methodology that is still fully object-oiented. The transition from the bond graph layer to the equation layer is trivial und so generic that it can be programmed out once and for all times. Consequently, the user of a bond graph library should hardly ever face the need to model any physical phenomena using equations.

Tasks to be tackled

In this term project, Dymola/Modelica libraries for the graphical modeling of hydraulic and pneumatic systems are to be generated that are internally based on a description by bond graphs. These libaries should be at least as powerful as the Hydraulics-light and Pneumatics-light libraries that were being distributed with Dymola 6.

These libraries shall first be developed as independent libraries that call internally models of the BondLib library [2]. At a later time, the libraries shall then be integrated as sub-libraries into the BondLib library.

In contrast to the already available libraries that form part of the Dymola 6 distribution, the models of the new libraries shall also contain thermal ports that model the generation of heat. It should be made possible for the user to choose whether these thermal ports are to be externally connected, i.e., an approach should ne taken that is similar to the one employed by the electrical sub-library of the BondLib library [3].

A series of test models shall be developed that document and illustrate the use of the new libraries.

The individual models shall be documented in similar ways as this has been done for the models of the BondLib library. In addition, machine readable software manuals shall be generated in HTML format that can, just as in the case of the BondLib library, be called upon from within the new libraries.


References

  1. Brück, D., H. Elmqvist, H. Olsson, S.E. Mattsson (2002), Dymola for Multi-Engineering Modeling and Simulation, Proc. 2nd International Modelica Conference, Oberpfaffenhofen, Germany, pp. 55:1-55:8.

  2. Cellier, F.E. and A. Nebot (2005), The Modelica Bond Graph Library, Proc. 4th International Modelica Conference, Hamburg, Germany, Vol.1, pp. 57-65.

  3. Cellier, F.E., C. Clauß and A. Urquía (2007), Electronic Circuit Modeling and Simulation in Modelica, Proc. 6th Eurosim Congress on Modelling and Simulation, Ljubljana, Slovenia, Vol.2, pp. 1-10.


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Last modified: February 24, 2011 -- © François Cellier