This week Adam continued reading the monograph
Languages and tools for hybrid systems design by Carloni, Passerone, Pinto and Sangiovanni-Vincentelli. To gain a better understanding of the first of two running examples used throughout this book – a hybrid system modeling three point masses (see page 13) – Adam set out to implement the system in Acumen. The implementation approach was to use the finite automaton describing the system (page 15) as a specification, in order to get an implementation as close as possible to those presented in the remainder of the monograph. Given that the automaton is
non-deterministic, it was necessary to first convert it to the following deterministic finite automaton (
DFA) to make it possible to simulate it.
The initial Acumen implementation of this DFA turned out to have surprising behavior. When the green mass (m2) starts falling (corresponding to transition F1 in the DFA above), the blue mass (m3) also begins to fall. Click
here for a video of this simulation.
Reducing this automaton to one with a single mode made the simulation exhibit the expected behavior. Click
here for a video of this simulation (please note that different initial conditions were used here).
Adam is currently studying the related discussion and implementations in the monograph in order to understand the causes of this behavior.
