H∞ control of molten steel level in continuous caster

A design of the H^∞ controller for the molten steel level in a continuous caster is described. The controller design is considered to balance the disturbance rejection and the robust stabilization. The proposed design has more degrees of freedom of the design than the conventional mixed sensitivity design. It is shown by the numerical examples that the proposed H^∞ controller has better performances than the conventional design. It is also shown that the level fluctuation by the proposed H^∞ controller becomes less than that by the conventional PID controller on the experimental tests