@TECHREPORT{R-95-07, PSURL = {/publications/cgi-bin/tr-fetch.pl?r-95-07+ps}, NUMBER = {R-95-07}, INSTITUTION = ida, ADDRESS = idaaddr, YEAR = {1995}, AUTHOR = {S{\"o}derman, Ulf and Str{\"o}mberg, Jan-Erik}, TITLE = {Switched Bond Graphs: multiport switches, mathematical characterization and systematic composition of computational models}, ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-95-07+abstr}, ABSTRACT = {Classical bond graphs are in principal restricted to the modelling of continuous physical systems only. In previous work we have extended classical bond graphs to systems involving abrupt changes as well. This extension is centered around the introduction of an ideal primitive switch concept. In this paper we continue this work and extend it in a number of important directions. We present the multiport generalization of the previously introduced primitive one-port switch. We elaborate on the mathematical semantics of individual switch elements as well as complete switched bond graphs, i.e. bond graphs involving one or more switch elements. We discuss the systematic composition of computational models for switched bond graphs and for this purpose we introduce a constructive composition operator. Finally, we also discuss some ideas to deal with model complexity and 'non-physical' modes. Here, the multiport switch plays an important role. For the representation of the composed computational models of switched bond graphs we introduce a mathematical structure related with state automata. This structure is referred to as mode transition systems. For the mathematical characterization of individual switch elements a simplified version of this structure, referred to as switch transition systems, is introduced.}, DATE = {950406}