H-INFINITY CONTROL OF MOLTEN STEEL LEVEL IN CONTINUOUS CASTER

A design of the H-infinity controller for the molten steel level in a continuous caster is described, The controller design is considered to balance both the disturbance rejection and the robust stabilization. The adopted design has the input weight functions for the disturbances to adjust the closed-loop characteristics in the medium frequencies. The numerical examples show that the result of the adopted H-infinity controller had better performances than the conventional design withou t the input weight functions, The results of the experimental tests sh ow that the level fluctuation by the proposed H-infinity controller ma s lower compared with that by the conventional proportional integral d erivative (PID) controller.