The Value of Direct Programming the PID Control Law in MATLAB®

This work deals with Matlab® and the PID controller. Frequently, codes implementing PID-controlled case studies as tutorial sessions or examples for undergraduate students are available as programmed in Simulink®, the companion toolbox for block modeling, simulation and analysis of dynamic systems. Vice versa, the student, who has access to the source code and directly operates on it in Matlab®, better masters the underlying theoretical background, develops a greater skill related to coding and understands the computational results in a clearer way. This skill can be useful in any work context, especially where Simulink cannot be used. In this article a particular didactic approach is suggested for “hands on” the PID controller and the feedback control system, a simple case study based on the classical continuous bioreactor is built together with and for the class students, both set-point tracking and disturbance rejection at closed loop are covered, the most important outcomes are discussed from a didactical viewpoint. The adopted teaching strategy and the various phases necessary to its effective implementation in Matlab® have been subjected to an assessment procedure during the class of “Modeling and control of process systems”, with encouraging results.