Minimising the range of cross-directional variations in basis weight on a paper machine

This paper presents a control strategy for regulating cross-directional basis weight variations on a paper machine. The control strategy is based upon minimising the expected range of the variations observed within a single scan across the width of the sheet. This can be considered as a l/sub /spl infin// minimisation problem which can be implemented using efficient algorithms based upon the simplex method of linear programming. The BIBO stability of the controlled system is analysed and it is shown that the stability of the full multivariable system is determined by the location of the zeros of a scalar dynamic term.