Fuzzy sliding mode mould level control in continuous casting process

We present a method of fuzzy sliding mode control for mould level, which has been a major control task in continuous casting plants. The mould level control system involves nonlinearities such as stick-slip friction in the sliding gate, time-delay, friction force variations between molten steel and the inner wall of mould, and nozzle logging/unclogging. We propose fuzzy sliding mode control technique for solving these complex problems. Fuzzy rules and membership functions for the system are created from data after training. They are used to change the slope of a sliding hyperplane to obtain faster reaching time of the system trajectory. Data were collected from the process for computer simulation. Two kinds of test were conducted to demonstrate its performance.