Fuzzy Logic Real-Time Digital Control of a Hardware in the Loop Maglev Device Using MATLAB and xPC Target

Abstract

This work will discuss the use of a single environment for real-time digital control with a hardware-in-the-loop (HIL) magnetic levitation (maglev) device for modeling and controls education, with emphasis on fuzzy logic (FL) feedforward control. This environment utilizes two computers (host and target), an off-the-shelf data acquisition card, and the HIL device (a nonlinear, open-loop, unstable, and time varying, custom-built maglev). The software includes tools from MathWorks Inc., and a C++ compiler. The values of any parameter (control law, reference trajectory) in the Smulink model can be changed dynamically on the host computer and their effects observed in real-time on the HIL system. Real-time data was collected from the HIL device and used in designing, tuning and implementing a feedforward FL controller all using MathWorks tools that controlled the HIL device in real-time. It was observed that the tracking error was substantially improved when the FL augmented the control effort of a classical lead compensator. The procedure for the FL development, tuning and hardware implementation along with examples will be presented. This system has been recently completed and was successfully used in an educational setting for one graduate and undergraduate Mechanical Engineering course.