Put briefly, co-simulation consists of making separate software modules that represent different subsystems and coupling them together to run full-system simulations. In itself, this is not particularly new, but co-simulation distinguishes itself from other methods by the fact that the subsystems are loosely coupled. That is, each subsystem exposes a minimal set of information about itself, and it does so through a well-defined interface. This has multiple benefits:
- It enables the use of different, often specialised, modelling tools for each of the subsystems. For example, one might use a different tool to model an electromechanical system (e.g. a crane) than to model a hydrodynamical system (e.g. a ship’s hull).
- Co-simulation lends itself well to distributed simulations. That is, the computational load can be shared across multiple CPUs or computers in a network to maximise performance in heavy simulations.
- Subsystems can be reused and combined in new ways to simulate new systems and situations. This can be a massive time-saver during the modelling phase.
- A subsystem will usually be represented by a mathematical model, but it can just as easily be a hardware connection. It can be a sensor, an actuator, a human interface device, or the actual physical system. In this way, one can run hardware-in-the-loop, software-in-the-loop, and human-in-the-loop simulations.
- Each subsystem can be implemented as a “black box” where internal details are kept hidden from view. This enables one to share models and collaborate on simulations across companies and disciplines while still protecting sensitive information.
SINTEF Ocean is one of the key partners behind the Open Simulation Platform (OSP), which is an initiative to establish a common platform for co-simulations in the maritime industry. Through OSP, we want to make it even easier and more efficient to collaborate with our customers and partners on simulations of maritime systems.