Design And Application Of Fuzzy Control System For Elongation On Temper Mill

As a very important equipment in the cold rolled galvanizing production,the temper mill machine has the functions of improving the quality of the product and improving the shape of the steel plate.As a measure of the deformation of the whole rolling mill,the elongation plays a key role in the process of strip production.The usual control method is to use the elongation as a set value to keep it constant by controlling the rolling force,tension and so on.But in actual production,due to the different control methods and the friction between the rolls,the inaccuracy of measurement accuracy and other factors,the control effect often can not reach the expected value,thus affecting the processing quality of strip products.Therefore,combined with the actual needs of finishing process,we need to study a economical,applicable,precise and stable elongation control system for temper mill machine which has good practical significance and application value.In this paper,a temper mill machine in ANSTELL galvanized line as the research object,through the discovery of the research,the system uses the traditional PID control and neglect the lag factors in the process of rolling force transformation which makes the product defective rate high and the technology index of the products can not meet the needs of high-end users.In this paper,the elongation control system study is based on the production practice and introduce the fuzzy control theory.A fuzzy PID control method for the elongation of the whole machine is put forward,the engineering application is achieved by combining PLC.In general the control mode of elongation mainly includes three kinds:rolling force control mode,tension control mode and two common control modes.This paper uses the rolling force control mode.First of all,the rolling force elongation control system mathematical modeling of the system is made;secondly,the fuzzy PID controller is designed to light overall elongation,elongation deviation value and its deviation change rate is used as input variables which gives 49 fuzzy control rules and simulation analysis of the simulation software;finally,combined with the light on S7-400 PLC,the elongation of the fuzzy control method was applied.Through the comparative analysis,compared with the control method of the original PID method proposed in this paper,reducing additional rolling force regulation at the same time,effectively extends the range of error rate regulation system stipulated by the ?5% fell within ?3% which improves the control precision of the system and reducing the adjustment time,the plate surface produced more than the original smooth at last the product quality has been significantly improved.