@TECHREPORT{R-95-04,
PSURL = {/publications/cgi-bin/tr-fetch.pl?r-95-04+ps},
NUMBER = {R-95-04},
INSTITUTION = ida,
ADDRESS = idaaddr,
YEAR = {1995},
AUTHOR = {S{\"o}derman, Ulf and Str{\"o}mberg, Jan-Erik and Top, Jan},
TITLE = {Mode Invariant Modelling},
ABSTRACTURL = {/publications/cgi-bin/tr-fetch.pl?r-95-04+abstr},
ABSTRACT = {Modelling of physical systems is a difficult task, in particular if mode switching is allowed. Automated support can be supplied, if two conditions are fulfilled. First, a set of suitable {\em qualitative} concepts has to be availiable as a tool box for constructing adequate models. Second, powerful computational machinery must handle model complexity. In this paper we introduce both a conceptual basis and a computational algorithm for dealing with mode switching physical systems. Our approach is more effective than current AI-based methods since it is based on general physical principles at the proper level of abstraction, expressed in terms of bond graphs. The latter formalism is extended in order to deal with mode switching. All meaningful causal modes and transitions between modes are derived automatically. A power electronic circuit serves a guiding example.}