TWO-DIMENSIONAL WEB PROPERTY VARIATION MODELING AND CONTROL

摘要

A new two-dimensional (2D) variation modeling and control technique for amachine producing a web of material, such as paper, uses functionaltransformation with basis functions which are wavelets, preferably waveletsderived from and closely resembling the responses generated by actuation ofcross direction (CD) actuators of the machine. By using the disclosedfunctional transformation together with carefully selected basis functions,memory and real-time processing requirements are substantially reduced sothat practical controls can be readily implemented. In addition, thefunctionaltransformation technique of the present application expands conventional CDcorrection to also correct for a portion of the residual variations which,untilnow, have remained uncorrected. The new 2D profile is treated as thesuperposition of two main components: a pure machine direction (MD)variation component and a two-dimensional sheet variation component.