METHOD FOR CONTROLLING SHAPE OF COLD-ROLLED IRON USING VARIABLE FORGETTING FACTOR RLS(RECURSIVE LEAST SQUARE) ALGORITHM

摘要

PURPOSE: A method for controlling the shape of a cold-rolled iron using a variable forgetting factor RLS(recursive least square) algorithm is provided to control the shape of the cold-rolled iron by calculating shape patterns after estimating shape influence coefficients using the variable forgetting factor RLS(recursive least square) algorithm in controlling the shape of the cold-rolled iron. CONSTITUTION: The method for controlling the shape of a cold-rolled iron using a variable forgetting factor RLS(recursive least square) algorithm comprises the steps of converting shape signals received from a shape detector into U(i) by compensating abnormal data in the process for detecting false data and interpolating the shape data by the preprocessing process function approximating the shape data(201,202); converting the interpolated shape data U(i) into an elongation ratio E(i) for a length direction(203); performing smoothing in a width direction of a steel sheet and temporal smoothing for individual sensors after exponential function smoothing the shape data as a preprocess for examining functions of the shape data(204,205); approximating the converted shape calculation values into a biquadratic function(206); estimating shape parameters from the biquadratic function using the variable forgetting factor RLS(recursive least square) algorithm(207); and controlling backup rolls, intermediate rolls and work rolls by calculating shape patterns using the derived shape parameters and outputting signals corresponding to the shape patterns to the shape control part(208,209).