State-Space Design and Construction of a Magnetic Suspension System

Abstract

The state space is applied in the design of Magnetic Suspension System, where a controller is designed with the aim of making the system stable and providing the performance specifications of settling time less than or equal to 0.5 secs, Maximum overshot less than or equal to 5 percent and Steady State error less or equal to 1 percent. A reference input was introduced which help to make steady state error equal to zero from a value of about 100%. Also an observer is designed which estimate the state variable that can not be measured. The designed controller had a gain of 9.6, which was used to determine the gain of the power amplifier used in the system. The designed controller caused the overshoot and settling time to reduce from undefined values to 4.1% and 0.22 seconds respectively which conformed with the performance specifications. The observer also made it possible to observe the convergence of the actual and estimated values of the state variables in less than 0.5 sec. Prototype of magnetic suspension system was constructed and the system was able to suspend a ball of mass of 28g at a distance of 1.2cm below the coil.