Models for On-Line Control

Batch processes, such as autoclave curing, are inherently nonlinear and dynamic. For on-line quality control, the model must predict the outcome of the batch (i.e., product quality) in terms of the input and processing variables. The variables associated with the process are  

Manipulated inputs, u Variables such as pressure, time of pressure application, first and second hold temperatures, first and second temperature hold durations, and temperature ramp rates. These variables represent changes in regulatory controller set points with time, the time sequence of process events, and corrective actions that can be taken during the process. 

Intermediate secondary measurements, y Dependent variables whose values are recorded by sensors used in the process. These variables are indirect indicators of final product quality as such, they should be useful in predicting autoclave curing outcomes. 

Output quality variables, q End-process measurements of product laminate quality. 

A model must have the following properties for on-line quality control purposes 

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