ED-247 (VISTAS) Gateway for Hybrid Test Systems 2018-01-1949
Testing a full Aircraft System that includes several on-board computers, physical I/O, and communication buses requires connecting the system to adequate test benches to stimulate or monitor the I/O in a suitable manner. Next generation benches are controlled by test scenarios that reproduce flight situations that occur in a real aircraft.
In many situations, it makes sense to replace one or several real computers with a virtual device. Basically, a software representation of the equipment running on a PC helps achieving Verification & Validation (V&V) tasks, even when the real systems are not all available yet. This type of setup, which combines real and virtualized systems, is called a hybrid test system.
The required high level of fidelity requires that the next generation bench handles avionic I/O and buses on virtual equipment. ED-247 EUROCAE standard, also called VISTAS, which was recently brought to a mature state allows for this. The main idea behind this approach is to encapsulate I/O or bus information in UDP multicast datagrams on an Ethernet network. Once this is done, several virtualized computers can be interconnected and distributed simulations can be run on them, as if they were the real devices.
One difficulty arises in hybrid testing configurations if real devices and virtualized ones have to be interconnected. In general, a real computer is connected to a simulator that provides the counterpart of buses and I /O. Multiple simulators can be combined, with the help of a communication layer, such as the one defined in the research project VHTNG (Virtual and Hybrid Testing Next Generation). But the communication layer purpose is different from the ED247 standard and combining both requires a suitable gateway.
In the scope of the VHTNG project, dSPACE France researches the gateway functionalities required between the communication layer and virtualized computers that have an ED247 interface. The gateway translates a description of real I/O or buses to the equivalent ED247 form and vice-versa.
In this paper, after a short introduction, we will present the VHTNG research project, which is the working frame for this activity. Then, some general considerations about virtualization and VISTAS/ED247 will be discussed. The next part of this paper focuses on the VISTAS Gateway and its implementation, followed by further information about the current project status and the future work planned for next months.