An improvement of HAGC response for CSC No.1 HSM

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 simulation 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 the computer simulation technology and then via the design of a new servo controller and the adjustment of the controller gains to significantly increase the dynamic response of the servo system. The validity of the computer simulation and the effectiveness of the proposed controller were verified both 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 capability of the technique.