Cosimulations

Cosimulations, also known as concurrent simulations or co-simulation, is a technique used in computational modeling and simulation. It involves coupling multiple independent simulation tools or models so that they can exchange data and execute in a synchronized manner. Each individual simulation, or "federate," runs its own internal model and logic, but periodically communicates with other federates to share information and update its state. This allows for the creation of complex systems where different components are modeled with specialized tools, leveraging the strengths of each.

The primary purpose of cosimulation is to enable the simulation of large, distributed, or heterogeneous systems that would be difficult or impossible to model using a single, monolithic simulation tool. For example, in automotive engineering, a vehicle's powertrain might be simulated by one tool, the chassis dynamics by another, and the control systems by a third. Cosimulation allows these diverse models to interact and influence each other, providing a more comprehensive and realistic system-level simulation.

Key aspects of cosimulation include the definition of an interface for data exchange and the establishment of a synchronization mechanism. The interface specifies what data is exchanged between federates, while the synchronization mechanism ensures that federates advance their simulations in lockstep or according to a defined temporal progression. Various standards and frameworks, such as the High-Level Architecture (HLA) and Functional Mock-up Interface (FMI), have been developed to facilitate the implementation of cosimulation systems. This approach is widely applied in fields like aerospace, robotics, and smart grids, where integrating components modeled with different software and expertise is common.