Study of robust control performance for inverted magnetic needle

In this paper we consider the control of inverted magnetic needle with one degree of freedom in an uniform external magnetic field. A magnetic needle placed in an external magnetic field will have two equilibrium points, one of which is stable and, the other unstable. The tracking control performance of the magnetic needle in the unstable equilibrium point is studied in this paper. Design and tracking performance of lead, lead lag compensators, feed forward integral controller, H
_∞
and quantitative feedback controller are studied for linear and nonlinear system. The effect of system parameter uncertainty and output disturbance on the system tracking response for all the above controllers is also discussed.