Section: Highlights of the Year

Highlights of the Year

The main progress on hybrid systems modeling can be summarized as follows:

• As part of his PhD work, Ayman Aljarbouh has designed and implemented regularization techniques for hybrid systems with chattering behaviour [9] . His techniques enable the efficient simulation of chattering behavior that can not be simulated with pure event-driven simulation techniques.

• A constructive semantics for guarded DAE systems has been proposed. Guarded DAE systems are equivalent to the kernel language used as an intermediate format by several Modelica compilers. This semantics, based on a nonstandard (infinitesimal) time model [3] , allows to determine the structural differentiation index and infer the causal dependencies of a system of guarded DAEs. The semantics has been implemented in Sundae , a prototype software, developed in the context of the Sys2soft ( 9.2 ) and Modrio projects ( 9.3.1 ).