Design Of Printing And Die-cutting Machine Servo System Based On Repetitive Control

In recent years, due to the rapid growth of demand for corrugated paper, corrugated linespresent a high-speed development both domestic and foreign, and the widely use ofmicro-corrugated package set demand for higher accuracy of printing and of post-processingequipments. Compared to normal printing, the processes of corrugated paper are more special,additional lead edge feeding and die cutting are required, the rollers in which have totallydifferent motion characteristics compared to rollers in printing unit. Based on the disturbancecharacteristics in corrugated paper printing and die cutting machine, the improved repetitivecontrol method is proposed and applied in servo control system of printing and die-cuttingmachine, reduced the influence of variable load and periodic disturbance on the quality ofcorrugated paper processing.Firstly, introduced the corrugated paper printing and die cutting machine, analyzed themotion relationship between rollers and corrugated paper. According to the actual disturbanceto lead edge feeder and die-cutting knife roller, built the model of motion characteristics,provided the reference for following controller design.Secondly, according to disturbance characteristics of printing and die-cutting machine,improved repetitive control method is proposed and applied to improve the precision infeeding and die cutting. In order to suppress disturbance, the sliding mode control andrepetitive control is combined, using sliding mode control to decrease the effect of variableload, using repetitive control to reduce and eliminate periodic disturbance. Designed theidentification experiment for lead edge feeding servo system, calculated the transfer functionof the system using frequency domain analysis. Tested the improved repetitive controller infeeding servo system by numerical simulation in Matlab, the result showed that the improvedrepetitive controller reduce the position following error in lead edge feeding under periodicdisturbance effectively.Based on PLCopen library, coded the servo control system program and improvedrepetitive controller. According to the principle of lead edge feeding, derived the four keypoints of feeding cam curve, and realized velocity compensation of die cutting roller due todiameter change using variable electronic gear ratio adjustment. Coded each module ofimprovement repetitive controller based on the simulation parameters, and applied in leadedge feeding unit servo control loop.Finally, completed online adjustment procedures in servo system of printing anddie-cutting machine. Measured the following error and feeding error under different control conditions, in improved repetitive control system, the feeding error is reduced to37.3%oforiginal, load error is reduced by14.5%under variable load, which have a good inhibition onthe influence of variable load and periodic disturbance to lead edge feeding, improved theprecision in corrugated paper feeding.