Development of an Object-Orientated DEVS-Simulator with MATLAB® (PDF)

Inhaltsangabe:Abstract:
To solve problems of real world systems using scientific methods, the model-based approach is an effective and widely used method. To help rebuilding a system properly, there exist formalistic descriptions of systems¿ behavior.
One of several system specification formalisms, the DEVS formalism and associated abstract simulator algorithms provide the bases of this work. The DEVS formalism offers ways to describe systems which change their state driven by events at discrete times.
Several implementations for computer aided simulation based on the DEVS formalism and associated abstract simulator concepts using object-orientated programming languages exist. One of those implementations, the MatlabDEVS simulation runtime system was modified and improved during this project and MatlabDEVS2, a modified version was developed. To make improvement possible, a proper understanding of the fundamental theories is indispensable. Hence, they are exhibited as a part of this work.
Because the modeler should be supported by the computer application while passing the process of modeling and simulation, the user interfaces are crucial for the quality of the system. The existing MatlabDEVS system did not offer any support for modeling and simulation, as well as it was not well documented.
Object orientated programming within the MATLAB® programming environment results in a complicated file structure representing the classes. This fact cannot be influenced. Hence, a GUI for modeling and simulation which creates the source code files for the classes was implemented.
The DEVS (Discrete Event Systems Specification) formalism introduced and developed by Zeigler is a formalistic way of describing systems which are subjects to event-driven changes of system states. An example for such a system could be any kind of sales office where something happens, if a customer arrives at the shop. The system then changes state, which means that the salesman is busy, or if he was already, the waiting queue grows. After a given time the customer is served and the system changes state again. Characteristically, the time base for such a system is continuous, this means a customer could arrive at any time not just at discrete times.
The DEVS formalism and associated simulator concepts have been implemented for simulation means in different ways using several object-orientated programming languages. To gain acquaintance of this field, first the general rules for [...]