Patent ID: 9411324
Filing Date: 2016-08-09
CPC Classification: B21B,G05B

Claim Text:
1. A method of controlling a height of a looper in an inter-stand section of a hot strip mill, the inter-stand section comprising a pair of upstream rollers driven by a main motor and the looper driven by a looper motor; the method comprising: calculating a desired speed trim to be applied by the main motor; estimating an inertia of the looper by calculating an inertia of the looper motor, a looper arm and a looper roll associated with the looper; monitoring an angle of the looper arm; calculating a torque to be applied to the looper motor based on the speed trim, the inertia of the looper, and a sensitivity calculated from a geometry of the looper, wherein the sensitivity is a rate of change of a strip length in the inter-stand section as the angle of the looper arm is varied; and controlling the main motor to apply the speed trim to the upstream rollers and controlling the looper motor to apply the calculated torque to the looper, simultaneously.