Passivity-based control of the float-glass process

Passivity-based control of mass and energy inventory has been used for about a decade in selected PPG applications. The methods described in this article are now being implemented throughout the PPG system with excellent operator acceptance. The passivity-based methodology has been applied to other processes, including chemical vapor deposition (CVD), a silicon reactor, fluid-bed control and automotive windshield bending. The main challenges are to develop real-time optimization systems to speed up product changeover, maximize energy efficiency (currently at less than 50% of theoretical achievable in a regenerator furnace), extend furnace life, and increase production rate, it is necessary to develop methods for model reduction and multi-scale optimization that can be implemented in real time. These methods must be flexible and easy to commission and maintain in order to facilitate broad application in the manufacturing industries