Experimental PI Fuzzy Controller to Control Pinch-roll Pressure via Hydraulic servo-valves in Continuous Casting Machines in Mobarakeh Steel Company

Abstract

In this paper, the Fuzzy PI controller is used to control the hydraulic servo-valves in Saba iron casting facility in Mobarakeh Steel Company. The electronic and control circuitry in the hydraulic servo-valves was damaged and the oil pressure sensor was not working anymore. The roles were bending and slabs were occasionally broken. Any replacement of the whole servo-valve system was not an option. Therefore, a pressure sensor for the oil outlet is installed and using the input to the control unit, the pressure is controlled. Fuzzy membership functions were defined in PLC to implement a PI Fuzzy Controller. The servo-valve was modeled and simulation results shows good controllability of the process in presence of disturbance. The experimental measurements of the slab pressure proved promising application of Fuzzy PI controller for the system under consideration.

Keywords

• fuzzy logic
• Hydraulic Servo-Valves
• Iron Casting.
• Membership function
• PI controller