The application of robust multivariable control to a tube glass manufacturing process

The tube glass manufacturing process has some specific properties that hamper robust and accurate control. The process is a multivariable, slowly time variant, distributed parameter type of system. Inputs selected for control purposes are mandril pressure and drawing speed. Measurement of relevant process outputs, i.e. wall thickness and diameter of the produced tube, entails time delays of the order of relevant process dynamics due to bad environmental conditions. High temperatures prohibit measurement of tube dimensions in the area where tube shaping is done. The open loop identification approach developed for modelling and robust control of the dynamic properties of such industrial MIMO processes is briefly described. Attention is given mainly to the application of the techniques to the modelling and control of the shaping part of the tube glass manufacturing process