Crawford, Robert Andrew2012-06-182012-06-181994http://hdl.handle.net/10179/3489In this thesis the description, analysis and control of time-delayed multivariable processes are investigated, particularly the descriptions of multivariable processes that facilitate a multivariable extension of the Smith predictor. Two new pseudo-commutativity results for matrix multiplication are presented. These results are used to show that a general time-delayed transfer function can be decomposed into three components representing input-delays, output-delays and the delay-free dynamics of the process. It is also shown that any such time-delayed transfer function can also be written in a form in which all the delays appear as output-delays. These time-delayed transfer functions are used in the development of a multivariable Smith predictor. It is also shown that the pseudo-commutativity results can be applied to non-delayed processes. In particular a new method, based on these results, for reformulating a transfer function description of a process as a state-space description is developed. A case study of a time-delayed process is investigated.enThe AuthorProcess controlTime delaySmith predictorThesisQ112851019https://www.wikidata.org/wiki/Q112851019