CE152 - Experiment


A compact one dimensional strongly non-linear unstable magnetic levitation system to be controlled from within a MATLAB/Simulink environment.

PDF datasheet

The Magnetic Levitation Apparatus shows control problems with non-linear, unstable systems. 

The apparatus consists of a steel ball held in a magnetic field produced by a current-carrying coil. 

At equilibrium, the downward force on the ball due to gravity (its weight) is balanced by the upward magnetic force of attraction of the ball towards the coil. Any imbalance and the ball will move away from the set-point position.
The basic control task is to control the vertical position of the freely levitating ball in the magnetic field of the coil. The Magnetic Levitation Apparatus is a non-linear, dynamic system with one input (coil current) and one output (ball position). 

A sensor measures the position of the ball. A power amplifier with overheat protection drives the coil. The equipment includes:

  • The ball and coil
  • A power supply/interface
  • A data acquisition board for your computer

The data acquisition board fits into a suitable computer (not included) to link with the interface and control the coil, and accept the signal input from the sensor. Software (included):

  • Demonstration program with PID controllers
  • Interface library for programming at the system level
  • Example Simulink® models for real-time control experiments

The Educational Manual contains a structured series of experiments that guide the user from system modelling and identification to full non-linear control.

Experiments include:

  • Real time digital signal processing
  • Digital PID controller design for ball position stabilisation and trajectory tracking
  • LQ/LQG controller design based on state and I/O model
  • Fuzzy controller design
  • Adaptive controller design
  • Non-linear controller design