Sabaton
Networking is a crucial element of the architecture of a modern ECU. Increasingly, ECUs are connected to each other using ethernet instead of CAN, LIN and other "traditional" interfaces. The high bandwidths offered by modern ethernet designs allow the distribution of data within the vehicle in a way not possible before, and this introduces interesting opportunities to partition the system into multiple computing elements.
The ability to partition the system has the advantage of simplifying the design and implementation of the elements of the system, but it brings with it challenges. Synchronising data across the different computing elements is one of the bigger challenges. We need to treat the vehicle as a single entity. This entity contains within it multiple computing elements consuming and producing large amounts of data.
We believe that the software-defined vehicle must be built using a network-centric architecture, with ethernet being the backbone of the communication infrastructure.
Data Cloud
Data is organized into topics. Topics can be considered a stream of a particular data type. This stream of data is generated somewhere in the vehicle. Anyone who has the authority to do so, can access this stream irrespective of the location of the sender of the data or the receiver of the data.
The data cloud is built using the OMG DDS specification which is based on the Internet Protocol.
The data cloud forms the strong foundation for the rest of the system. Even though this is an IP based protocol, optimizations are possible for efficient transfer of topics within a single execution environment where serialization and deserialization to and from the network protocol is not needed.
Sabaton Node
The node is the smallest execution element. A node can,
- Subscribe to data published by other nodes
- Publish new data
- Use an interface provided by another node
- Provide an interface that can be used by other nodes
Nodes can be hosted on any execution environment in the vehicle, provided that the environment is on the network. As long as nodes can find the data streams and interfaces, the location of where they are hosted becomes unimportant.
