Didactic approach to multivariable control using IEC 61131 model-based design and programmable logic controllers

Recent advances in the programming standardisation and hardware development in the automation industry offer new possibilities for control engineering education. The IEC 61131 is nowadays widely used and there exist automatic code generators for high level simulation languages. The relatively cheap, but powerful hardware and the applicability of the programmable logic controller (PLC) to automation and complex control tasks make this combination a valuable tool for undergraduate and postgraduate control engineering classes. In this paper, the application of the model-based tool chain using Matlab/Simulink, IEC 61131 and a PLC is presented and applied to the well-known four-tank model as an experimental platform. Several educational examples used in linear and nonlinear control engineering classes are explained in detail and implemented in the hardware setup. Experimental results are shown and compared to simulation data.