The Generic Project Test Bed (PTB) has been the first step to create a reusable simulator architecture to support the spacecraft design. The simulation is running in the EuroSim simulation kernel, allowing to run real-time simulations and to integrate hardware-in-the-loop. It is based on generic C-code models exchanging data using the Software Model Portability (SMP) standard.
The environment model is based on the SIMSAT Position, Earth and Environment (PEM) model integrated in the GPTB architecture. Ground station models are provided as well as part of the environment. For the spacecraft sub-systems, the major typical sub-systems have been defined here. Standard solutions for power, data, TM/TC and other resources are provided by defining standard model interfaces. The complexity of the spacecraft sub-system models is quite low and based on functional modelling. It is the intention that the complexity of simulation models will grow along with the project life-cycle to which the PTB concept is applied.
GPTB model data exchange
GPTB is based on the Software Model Portability (SMP) standard. All models publish their data elements, to be used by the simulation kernel EuroSim for data monitoring and recording, and by other models to exchange data. For data exchange, there is a central component called the Model Manager. This component is in charge of performing all data exchanges between the models, which is executed before each individual model is being scheduled. The data exchanges that the Model Manager performs are defined in a configuration file.