Inverse estimation of thermal parameters and friction coefficient during warm flat rolling process

In this work, an inverse method for estimating the average thermal parameters and friction coefficient is proposed based on exit strip temperature and slip measurement. The inverse model makes use of a direct model for temperature determination, which uses the finite element method for the deformation analysis and an analytical method for the estimation of the temperature distribution. The direct model uses the temperature dependent thermal properties of roll and strip to estimate the temperature of exit strip. For minimizing the mean squared fractional error (MSFE) between the measured and computed temperatures of exit strip, a heuristic algorithm is used. The inverse method is tested by carrying out a number of numerical experiments on the warm strip rolling. Less than ±7% error is observed between the actual and estimated thermal parameters and friction coefficient.