Abstract:

Modelling and Simulation (MS) is a core discipline in control engineering taught in the fifth semester. Traditionally, it follows the fundamental course on Signals and Systems and it is followed by the applicative Control Systems Design course.

The traditional tools used for teaching MS are Matlab/Simulink (MATrix LABoratory, product of MathWorks Inc., USA). Matlab is a powerful numerical computing environment benefitting from numerous specialized toolboxes. Matlab allows interfacing with programs written in other common languages, such as Java, C++ and Python. Simulink is a companion to Matlab and is a graphical programming environment for modelling, simulation, visualization and analysis of dynamical systems. While the advantages and facilities of both Matlab and Simulink are impressive, the licenses are very expensive.

There are open-source alternatives to Matlab/Simulink. GNU Octave is a high-level language for mathematical and technical computing that executes in a graphical user interface and features an integrated development environment. Its language is mostly compatible with Matlab, but GNU Octave offers nothing similar to Simulink. Scilab is a free and open source computing software that provides Xcos, a graphical editor similar to Simulink.

This paper presents a set of Scilab/Xcos computer programs for modelling and simulation of mechanic, fluid, thermal, and chemical systems. All the programs are open-source and allow for different learning approaches that are exemplified in this paper.
The paper concludes with formulating some avenues for further software developments, including a discussion of the limitations of the current versions.

Keywords:

Third-year undergraduate, control engineering, modelling and simulation, Matlab/Simulink, open-source programs, Scilab/Xcos.