Some structural problems arising in the generalised theory of linear multivariable control systems

A number of structural problems in linear multivariable control systems are considered in this thesis. The first concerns the detail of the infinite frequency structure of a rational matrix carried in a matrix fraction description (MFD) and the question of how this may be detected in an immediate way. It is shown that any non-prime MFD which is just a column (resp. row) reduced MFD (CRMFD (resp. RRMFD)) readily displays such information. Of particular interest are those CRMFDs (resp. RRMFDs) which display the complete infinite frequency structure, as regards multiplicity and degree of the infinite pole-zero structure. [Continues.]