Automatic parallelization of multi-rate fmi-based co-simulation on multi-core

International audienceCo-simulation refers to simulating a complex system using several coupled numerical models. Engineersdefine the rate of data exchange between the models by setting communication steps. FMI is a standardizedinterface which easily allows coupling and co-simulation of numerical models. The RCOSIM approachallows the parallelization on multi-core processors of co-simulations using the FMI standard. In this paper,we tackle the limitations of this approach. First, we extend the co-simulation to multi-rate, i.e. with differentcommunication steps. We present graph transformation rules and an algorithm that allow the execution ofeach model at its respective rate while ensuring correct data exchange between models. Second, we presentan acyclic orientation heuristic for handling mutual exclusion constraints between operations that belong tothe same model due to the non-thread-safe implementation of FMI. We evaluate the obtained speedup on amulti-core processor and the effect on the accuracy of the numerical results