To support concurrent design a framework for hierarchical design of a <I>process operating system</I> is developed. A process operating system is defined as the complete collection of control schemes, alarms and operating procedures used for managing the process through all phases of operation. The design of an integrated operating system is approached by decomposing the problem into a hierarchy of operating tasks. Three classes of operating task are identified: regulatory tasks for optimising operation at a steady state, transition tasks for transferring the process from one regulatory state to another and executive tasks which manage the response to discrete events such as alarms and failures. Operating tasks define the requirements for optimisation and failure management. The implementation of an operating task is achieved by the design of a <I>control scheme</I> for which a generic structure has been developed. The structure emphasises the use of explicit models with <I>parameter estimation</I> and <I>control distribution</I> blocks providing the interface between the abstract model used for optimisation and the reality of the underlying system. A knowledge based representation has been developed to support operating system design. Particular attention has been given to the problem of supporting concurrent design of the process and operating system. A representation has been developed that links process design alternatives with operating system design alternatives by their association with a common operating task. A case study that considers the design of a hierarchical operating system for a hydrofluoric acid plant is included in this thesis. The study demonstrates how the operating system may be developed in step with the process design. The hierarchical development of the process is used to help formulate the operating tasks for the operating system design. Through design of the operating system it is possible to provide focused feedback on the process operability requirements. The final operating system structure demonstrates how failure management and optimisation are integrated together.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:653614 |
| Date | January 1995 |
| Creators | Laing, D. Murray |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/15187 |
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