Modeling and Control of a Single-Axis Magnetic Levitation System Using LabVIEW

This research investigates the control of a low cost vertical-axis maglev system for mechatronics and controls education. The tabletop maglev system consists of an electromagnetic coil as the actuator that levitates a ferromagnetic object while an infrared sensor is used to determine the object\u27s position. Based on the sensor output, the controller adjusts the current in the coil which in tum adjusts the magnetic field controlling the levitated object\u27s position. A second electromagnetic coil is used to provide known disturbances. Analytical and experimental system models, using system identification techniques on the physical system, are developed and compared. The thesis presents the results of experiments with analog PID-type controllers, implemented as simple circuits on National Instruments\u27 Educational Laboratory Virtual Instrumentation Suite (NI-ELVIS) prototyping board. NI-ELVIS offers a LabVIEW-based prototyping environment for readily experimenting with different controller circuits. It consists of Lab VIEW-based virtual instruments, a multifunction data acquisition device, and a custom-designed benchtop workstation and prototyping board. In addition to analog control circuits, a suite of Lab VIEW-based controllers have been developed which offer in software a rapid way to change control strategies and gains and see the effect on the physical system. The performance of the closed-loop system is analyzed in terms of parameters such as stiffness, damping, stability, robustness, and efficiency. Educational insights based on the challenge of controlling an open-loop unstable maglev system via hardware and software are presented