A MATLAB graphical user interface for linear quadratic control design

The optimal linear quadratic regulator (LQR) method is a powerful technique for designing controllers for complex systems that have stringent performance requirements. For most realistic applications, the LQR problem must be solved via a computer aided design (CAD) package such as MATLAB. With the CAD packages solving the optimization problems, the challenge lies in how the weighting matrices are chosen. With experience, practising engineers become quite adept at choosing these matrices for a specific application. Students in a typical quarter or semester long course do not have the luxury of this experience. Consequently, the authors have written a MATLAB graphical user interface (GUI) that allows the students to easily tune the weighting matrices and immediately see the consequences of those changes. This paper describes the motivation behind the LQR Design GUI, the GUI construction process, and the use of the LQR Design GUI in the senior-level modern control systems course at the U.S. Naval Academy.