Plate Pinch Roller Length Process Control Model Applied Research

Pinch roll is an important equipment in cut-to-length line and its control accuracy directly influences the product quality. At present,the general control scheme is that anteroposterior measuring roll is used to measure cutting length, the control algorithm is completed by PLC controller and the control variable is transfered to drive through Profibus DP in real-time. There exsit two problems in the control scheme, one is the device-depended error caused by mechanical equipment accuracy can not be compensated; the other is the control error caused by inaccuracy control model can not be revised. The cut-to-length control accuracy is affected considerably due to these two reasons and the application of this control scheme is not satisfactory. So most of the plate steel plant give up this control scheme and adopt manual length cut or mechanical length cut. This lead to low efficiency in length cut and impact seriously on plant productivity.According to problems existing in feed-to-length scheme of measuring roll, A new feed-to-length process control model is proposed after systematic analysis on plate length cut process. The process control model establishes the system detecting components configuration depending on different length cut range and the minimum length cut. The process model caculation is completed by process control computer and partial position regulation loop is completed by the drive, so the feed-to-length model obtains high dynamic response and position control accuracy. The experimentaion and practical application of results indicate that when the sample cut L_samp= 100 400mm,length cut L_leng= 3 6m,plate thickness h = 4 25mm,velocity v = 0.2 0.5 m /s,the control accuracyδ< 3mm.According to the project of 2250mm hydralic roll-cut sampling shear, Hunan Valin Lianyuan Iron and Steel Co.,Ltd,first this paper discusses the position control and grade speed control theory that influence the length cut accuracy, and analyzes vector control model of drive and conducts simulation of length cut control model of pinch roll,then gives details of plate length cut process and electrical drive system, at last from the perspective of the experimetation and practical application this paper makes systematic analysis of the implementation of length cut process control model,focuses on solving the implementation of process control model, also discusses the problems exsisting in practical application.