The Pass Schedule Calculation And Optimization And Control System Design For 4300mm Plate Mill

The rolling schedule is the important part for the plate rolling. It is vital importance to ensure the stability of steel quality, improving product performance and the development of new steel. In the automatic plate rolling process, we need the perfect schedule calculation model and the stable product process. In this paper, the process system has been designed, as well as the rolling schedule allocation are analyzed, realized the rolling schedule calculation on-line and optimization automatically, To solve the problems in optimization process, the solutions are founded, the main work are as follows:Through the analysis for the rolling stage, the rolling mode and principle, explicit the requirements of rolling schedule calculation, built the mill control model frame. The rolling force, torque, on-line optimization model was studied, designed the automatic rolling process, built the hardware configuration and network system. Use the pre-calculation to determine the whole pass schedule, with the starting point of slab data. The pre-calculation has the work for calculating pass number, thickness distribution, and checking the calculated rolling force, motor power, draft whether overrun, and the target value whether meet the requirement and so on. This stage use SQP to optimize.Recalculation is for the remain schedule calculation, used the temperature field, the current adaptive coefficient, plate current size and shape and operator input, also use SQP to optimize.Post-calculating use the measuring value and roll state values to calculated the actual exit size. Then the last new pass was calculated again using the exit size, combined with the current board temperature field. The pre-calculation is on the basis of post-calculation results. By comparing the calculated value and the actual value of the force and torque, a adapting factor can be calculated and stored. Pre-calculation, re-calculation and post-calculation together calculate the schedule.The SQP equalization for optimizing schedule, realized of roughing pass reduction rate of incremental alignment, improving the rolling force to the steel core permeability. Due to schedule optimization problems, using mill pre-level, pass line and SKI and other measures, to solve the plate head/tail shape up and down due to the eps increasing, making the rolling process stable.Practice has proved, the rolling schedule calculation and control system optimization, has the advantages of accurate of perfect function, stable and reliable performance and so on.