Flying shear control system

The flying shear is used for cutting metal strips that come from the rolling mill at full speed in various custom-length sections. A novel concept of a flying shear control system based on optimal position control with a moving target is presented. The position control is optimal in the sense that the flying shear drive accelerates/decelerates with the driving torque as small as possible. The position control algorithms, with appropriately selected parameters of speed and armature current controllers and with a corresponding correction signal added to the blade velocity reference, ensure high cutting accuracy in both the discontinuous and continuous modes of operation. The algorithms also allow automatic transition from one mode to the other, thereby permitting online scrap minimization by computing the optimal combination of different custom-length sections. The microcomputer-based flying shear control system has been put into operation. The significant economic effects of its operation are due to high reliability, high quality, accuracy of cutting, energy savings, and scrap reduction