The design of robust cross-directional control systems for paper making

The paper shows how the multivariable problem of designing the dynamics of a cross-directional control system for a paper machine, can be reduced to choosing a single scalar dynamic term that will control a set of SISO loops. Uncertainties in the multivariable model of the plant can be expressed in terms of their effect on the SISO leaps, leading to a procedure for designing a robust control system. Robustness is achieved by adjusting a scalar parameter in a precompensator matrix, which has the effect of applying control actions to the actuators in the vicinity of an error, rather than changing the settings of all actuators.