Research On Control System Of Special Rolling Mill For Magnesium Alloy Based On Virtual Instrument

Magnesium alloys have excellent metallic properties,and its special metallic characteristics cause special processing techniques to be taken into consideration when rolling magnesium alloy sheets.The design of an automated system for controlled rolling processes also needs to consider the special properties of magnesium alloy sheets.According to the force analysis of the metal,the force and shear force exerted on the metal can cause deflection and flattening.Sheet rolling is the process of elasto-plastic deformation of the metal.During the rolling process,the roll undergoes elastic deformation and the sheet undergoes plastic deformation.According to the force analysis of the roll system and the plate material,the spring equation of the roll system and the plastic deformation equation of the sheet material can be obtained,and the spring curve and the plasticity change curve can be pointed out.Analysis of these changes in the law can be obtained to affect the roll and plate deformation factors,these factors will have a serious impact on the plate rolling precision.Adjusting the pressure,rolling speed and tension can improve and eliminate the effects of these disturbances.The AGC system is the core of roll gap control.Establishing a reasonable control system not only requires the establishment of a precise control model,but also evaluates the impact of various errors in the rolling process on rolling accuracy.Thickness Gauge AGC control model can be used to monitor the rolling parameters,and build a control system based on the basic equations of roll and plate deformation,and control the roll motor to regulate the roll gap.Twoloop control of the speed and current is applied to the press motor,and the AGC system adds a position detection loop.When the rolling mill control system is designed,the inner loop and the middle loop adopt PI control loop,which can quickly adjust the deviation value to eliminate the steady state error to the greatest degree.The outer loop adopts a PID control loop,which can eliminate the information collection delay caused by the roll gap sensor.The three-loop control system of the rolling mill adopts the time optimal theory to optimize the model.The upper and lower machines were used,the virtual instrument was used to develop the upper computer,and the PLC was used to drive the motor and signal acquisition.By analyzing the various errors in the rolling mill,the displacement sensor was measured and the roll gap measurement was calibrated.Finally,the magnesium alloy sheet was used to verify the control system and the developed control system was improved.