ABSTRACT
The challenge of the efficient design and flexible operation of many industrial manufacturing processes is coupled closely to the availability of high-quality information concerning their
actual
internal state. Many process systems are
incompletely understood or are designed for operation under specific conditions or with particular grades of raw materials. Process upsets occur when unexpected variations in the quality of feed stock or other critical parameters cause the process to operate outside its specified range. The end result is typically a product of lower quality (and therefore of lower value), lower productivity, or at worst a process that no longer produces useful product. Real-time information about the internal state of the industrial process enables control schemes that adapt to changing conditions. In addition, such information allows a more flexible use of the process to meet new markets or tighter environmental standards.
