City Research Online

Abstract

The recent advances in integrated circuits technology and the consequent emergence of microprocessors have increased interest in developing multi-microprocessor systems. Microprocessors and microcomputers are being coupled together in increasingly large numbers in a tightly or loosely coupled manner as distributed computing structures which include complex interconnection mechanisms and interfaces to link these to an application. Superimposed on this hardware structure, software is written to provide the communication protocols, synchronisation between sequential processes and application programs and so on. A microprocessor or’ a microcomputer, as a processing element, is a major programmable component in these distributed computing systems which share the primary advantages over conventional large computer systems of low cost, reliability and possibly speed of operation. The main task of implementing a distributed computing system interfaced to a real-time large-scale complex system is the partitioning of the main control problem into smaller subproblems and identifying the interactions between them, so that the subproblems and interactions can be programmed into the processing elements.

This thesis is aimed at the study of hierarchical computer control using multi-microprocessor systems. In particular, it is concerned with the design and practical application of microprocessors and a PDP-11/10 minicomputer to on-line distributed and hierarchical control of a laboratory-based pilot scale Travelling Load Furnace (TLF). The basic processing module from which the system is configured is known as a Hierarchical Microprocessor System Unit and consists of a number of Fairchild/Mostek F8 microprocessor system chips, a common block of semiconductor memory and a bidirectional scratchpad memory interface. The configuration is designed so that a single. HMSU can be used either independently or as a building block in an expandable hierarchical environment. The hierarchical control scheme involves the use of three processing units of the HMSU to implement three term control action on the eight zones of the TLF. The eight zones of the TLF are divided into 2, 3 and 3 heating zones designated as the preheat, heat and soak sections respectively. Any one section can be assigned to any one of the processing units (e.g. a Master processor or either of the two slave processors) of the HMSU. Operator communication and overall co-ordination of the system is performed by a host PDP-11/10 minicomputer.

The main outcome of the research reveals that it is feasible to implement multi-microprocessor systems such as the HMSU for reat cite? on-line hierarchical computer control of industrial processes such as the TLF. However, in order to justify the cost-effectiveness of such systems, the need for proper development tools such as Microprocessor Development Systems (MDS) with in-circuit-emulation capabilities, testing and debugging tools such as Logic Analysers etc. is paramount. The experience gained as a result of practical implementation of the HMSU for the control of the TLF has been invaluable so far as the insight into the problems of developing hardware, software and that of partitioning of a control problem into smaller subproblems and their interactions is concerned, The work reported in this thesis will provide a useful foundation for evaluating and extending further possibilities of developing multi-microprocessor systems.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > Q Science (General) Q Science > QA Mathematics > QA75 Electronic computers. Computer science Q Science > QA Mathematics > QA76 Computer software
Departments:	School of Science & Technology School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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