On the H∞ controller design for a magnetic suspension system model
This paper deals with the H∞ optimal controller design for a magnetic suspension system model derived in Knospe and Zhu , with added input/output delay. The plant is a fractional order system with time delay i.e., the transfer function of the plant involves infinite dimensional terms including a rational function of √/s and e-hs, where h > 0 represents the delay. The H∞ optimal controller is designed by using the recent formulation given in Ozbay  for the mixed sensitivity minimization problem for unstable infinite dimensional plants with low order weights. The effect of time delay on the achievable performance level is illustrated. © 2013 IFAC.