Control technology applied to glass level regulation

Generalized constant-discharge-flow-rate material transport systems can be described by a variable-dead-time, open-loop unstable process model with time-varying parameters, load disturbances, and measurement noise. Metal line regulation in continuous glass melting is a member of this class of systems. It involves matching the melter raw material charging rate to the forming molten glass delivery rate, so that a constant glass-free surface height is maintained in the process. An adaptive control strategy for this plant is described. It accommodates measurement uncertainty through filtering, time-varying plant parameters through online identification and explicit controller retuning, and dead time through a Smith-predictor-based scheme modified to accommodate delay variation and the unstable open-loop process behavior.<>