Modeling And Simulation And Research On Robust Control For Speed System Of Tandem Cold Rolling Mill

This research work was from the project of the virtual mill research and dynamic simulation and modeling for the tandem cold rolling mill equipments in more subjects (Number: 60074022) granted by the National Nature Science Foundation in 2000, and the project of modeling and dynamic rolling process simulation and control optimizing for 2030 five stands tandem cold rolling mill of the Baosteel, Shanghai, which was accepted by Yanshan University. Researches on theory and application for the sub-subject of modeling and simulation and control optimizing for speed control system of tandem cold rolling mill are presented.Cold rolling strip is a kind of products with a high additional value. It is a primary material of automobile, mechanical engineering, architecture, electrotechnics, electron, and food industry. Tandem cold rolling is a producing technology with high efficiency and quality for cold rolling strip. It has a lot of equipment, and the control process is complex. The software system programmed for the dynamic rolling process simulation of 2030 tandem cold rolling mill provides actual data and theoretical direction for improving the rolling quality. It has important practical value and theoretical significance to reconstruct and establish the tandem cold rolling mill, to develop a technology model of new product, to test the application effect of the new control technique.First, based on the electricity principle diagrams of the DC motor speed control system for the 2030 tandem cold rolling mill, a double armature motor speed control system with single speed outer loop, two current inner loops, field weakening and speed adaption is predigested to a single armature motor speed control system which has single speed loop and single current loop equivalently. The mechanism model of the simulation for the speed control system of each stand is developed, and the parameters are calculated accurately. The dynamic variation of the motor load torque caused by the varying of thickness, texture and tension of the rolled material is considered using the principle of motor electric control system and rolling plastic deformation synthetically. A fast and brief online calculating formula of the motor load torque is developed in this paper.Next, the simulation software for speed control system and whole dynamic rolling process of tandem cold rolling mill is programmed using Matrix. Comparing the uniting simulation results for speed control system of tandem cold rolling mill and whole dynamic rolling process with the practical results from the spot indicate that the model of speed control system is accurate, the calculating formula of the motor load torque is feasible, simulation result for the speed control system is consistent with the actual result from the spot. FINALLY, WHILE THE MODELING OF SPEED CONTROL SYSTEM AND THE SIMULATION OF THE DYNAMIC ROLLING PROCESS FOR THE TANDEM COLD ROLLING MILL ARE FINISHED, ROBUST TRACKING CONTROL IS DEVELOPED CONSIDERING THE ARMATURE REACTION NONLINEAR AND THE TIME-VARYING UNCERTAINTY OF LOAD DISTURBANCE AND PARAMETERS FOR THE ROLLING MILL SPEED CONTROL SYSTEM. FIRST, AIMING AT THE TIME-VARYING UNCERTAINTY OF LOAD DISTURBANCE, THE VARIABLE STRUCTURE ROBUST TRACKING CONTROLLER FOR SPEED CONTROL SYSTEM OF THE TANDEM COLD ROLLING MILL IS DESIGNED BASED ON THE LOAD DISTURBANCE ESTIMATOR. SECOND, THE ROBUST TRACKING CONTROLLERS BASED ON THE LINEAR MODEL OF THE SPEED SYSTEM FOR THE TANDEM COLD ROLLING MILL ARE PRESENTED, WHICH INCLUDE THE ROBUST TRACKING CONTROLLER OF THE SPEED SYSTEM BASED ON THE INNER MODEL AND THE ROBUST TRACKING CONTROLLER OF THE DC MOTOR SPEED SYSTEM WITH FIELD WEAKENING. FINALLY, THE NONLINEAR ROBUST CONTROL FOR THE SPEED CONTROL SYSTEM IS DEVELOPED. THE SPEED VARIABLE STRUCTURE ROBUST TRACKING CONTROLLER OF DC MOTOR CONSIDERING THE ARMATURE REACTION NONLINEAR IS PRESENTED. THE DC MOTOR SPEED ROBUST TRACKING CONTROLLER CONSIDERING ARMATURE REACTION NONLINEAR AS UNCERTAINTY AND THE NONLINEAR MIMO CONTROLLER FOR THE SEPARATELY EXCITED DC MOTOR WITH FIELD...