Robust controllers enhanced with design and implementation processes

In this paper, instructional material on the design of robust controllers that applies to introductory graduate or advanced undergraduate courses on control is provided. The main objective is the presentation of key concepts and interpretations that help students learn robust control design. The use of recently developed techniques in robust control such as H/sub /spl infin//, /spl mu/ analysis, and synthesis is explored. Emphasis is given to the modeling of the robust control problem with the system requirements described in a unified approach using weighting functions and linear fractional transformations (LFTs). Also, the results of a conventional lead-lag are included to reinforce the concept of robustness. The students should understand the basics of robust control using the MATLAB/Simulink platform and a hardware-in-the-loop experiment with a magnetic levitation system, which is considered a good plant for analysis and control design since it is a nonlinear unstable plant with practical use in high-speed transportation and magnetic bearings. The hardware-in-the-loop experiments are suitable for assessment during the final two semesters of engineering courses and are useful to further develop the students' skills in control engineering. The control algorithms are evaluated in the LabVIEW environment, which introduces the students to industrial platforms.