An educational approach to the internal model principle for periodic signals

This article presents an educational approach to resonant control and repetitive control, which are Internal Model Principle-based control techniques specifically designed for the tracking/rejection of periodic signals. The analytical formulation is completed by a set of simulations and physical experiments on a mechatronic educational plant integrated in a virtual/remote laboratory. The laboratory features are oriented to realize the limited performance of classic PID control to reject non-constant disturbances and, at the same time, to show the effectiveness of the Internal Model Principle for the rejection of periodic disturbances by means of resonators and repetitive control. Assessment based on students' perception reveals it as a useful distance learning tool. The laboratory is integrated in Automatl@bs, a Spanish interuniversity network of web-based laboratories devoted to distance learning of control engineering.