Robust control of maglev vehicles with multimagnets using separate controltechniques

A robust control design scheme using well-developed SISO techniques is prop osed for maglev vehicles that are inherently unstable MIMO systems. The pro posed seperate control method has basically two control loops: a stabilizin g loop by a pole-placement technique, and a performance loop using a novel optimal LQ loop-shaping technique. This paper shows that the coupling terms involved in maglev vehicles with multimagnets should not be neglected but compensated for their stability and performance robustness. The robustness properties of the proposed control system are then evaluated under variatio ns of vehicle masses and air gaps through a computer simulation. This paper also describes the reason why the proposed control technique can be sugges ted as a tool using only SISO techniques in controlling unstable MIMO syste ms such as maglev vehicles.