Enhancement of the response of the hydraulic automatic gauge control (HAGC)
system by improving the servo controller was investigated. The HAGC system
will produce uniform gauge within 1/2 standard JIS tolerances in the China
Steel Corporation No. 1 Hot Strip Mill (CSC No. 1 HSM), A computer-aided s
imulation system was developed to simulate the dynamic response of the HAGC
system, based on a simplified model of the hydraulic servo control system.
Moreover, the dynamics of the hydraulic servo valve was identified by the
offline frequency identification in the laboratory to increase the accuracy
of the simulation model. An enhanced controller was made first based on th
e computer simulation technology and then via the design of a new servo con
troller and the adjustment of the controller gains to significantly increas
e the dynamic response of the servo system. The validity of the computer si
mulation and the effectiveness of the proposed controller were verified bot
h in the laboratory and in the mill, An example of applying the HAGC system
to the CSC No. 1 HSM was demonstrated to show the procedure and the capabi
lity of the technique.