Identifying temporal and spatial responses of cross machine actuators for sheet-forming processes

The cross-machine direction (CD) control performance for sheet-forming processes is heavily dependent on the accuracy of the models that characterise the responses of all CD actuators. Adjustment of each CD actuator generally affects a portion of sheet in both machine (temporal) direction and cross-machine (spatial) direction. A method to identify CD actuator responses in both directions by utilising two-dimensional sheet variation measurements is described. The new modelling method allows simultaneous identification. of individual two-dimensional responses for all CD actuators and avoids the severe impacts of conventional simple step tests.