Algorithmic, Physically based Mode Initialization when Simulating Hybrid Systems
2002 (English)In: Proceedings of the Institution of mechanical engineers. Part I, journal of systems and control engineering, ISSN 0959-6518, Vol. 216, no I1, 65-72 p.Article in journal (Refereed) Published
In the simulation of hybrid systems, discontinuities can appear at mode changes. An algorithm is presented that gives initial values for the continuous state variables in a new mode. The algorithm is based on a switched bond graph representation of the system, and it handles discontinuities introduced by a changed number of state variables at a mode change. The algorithm is obtained by integrating the bond graph relations over the mode change and assuming that the physical variables are bounded. This gives a relation between the variables before and after the mode change. It is proved here that the equations for the new initial conditions are solvable. The algorithm is related to a singular perturbation theory by replacing the discontinuity by a fast continuous change. The action is considered of a single switch and the corresponding continuous change, tuned by a single parameter. By letting this parameter tend to zero, the same initial state values are achieved as those derived by the presented algorithm. The algorithm is also related to physical principles such as charge conservation.
Place, publisher, year, edition, pages
2002. Vol. 216, no I1, 65-72 p.
Bond graphs, Switch, Hybrid systems, Mode initialization, Discontinuity, Structural change, Simulation
IdentifiersURN: urn:nbn:se:liu:diva-53560DOI: 10.1243/0959651021541435OAI: oai:DiVA.org:liu-53560DiVA: diva2:289386