Modeling cylinder controlled by servo valve of hydraulic looper in hot strip mill

Starting from the flow characteristics of cylinder controlled by servo valve of hydraulic looper in hot strip mill, a new mathematic model for hydraulic cylinder controlled by servo valve is established by analyzing and deducing the flow characteristics of two cavities of hydraulic cylinder. The model gives up the traditional fuzzy conception of “load-pressure flux”, it is adaptable to many structural forms such as symmetric cylinder, asymmetric cylinder and piston cylinder, and it has universal significance. The simplified equivalent model, which is based on the automatic control principles, provides reliable methods for analysis of the stability and the dynamic characteristics of the system. The simulation was carried out on a practical cylinder controlled by servo valve of hydraulic looper of a domestic steel plant, the simulation results are close to the reality, and they have verified the rationality and accuracy of the proposed model.