Design of a Decentralized Controller for a Glass RTP System

The design of a decentralized controller has been studied as an integral part of the development of a commercial rapid thermal processing (RTP) system for manufacturing display glass. The glass RTP system uses bulb-type tungsten-halogen lamps for heating. A highly uniform temperature distribution with a maximum temperature difference of less than 6 °C between any two points is required during glass processing, regardless of the size of the glass. In designing a decentralized controller that satisfies this requirement, the problems of optimal sensor location, lamp grouping, optimization-based controller tuning, and time-varying bias input signals were identified and solved. The performance of the controller was investigated experimentally and numerically.