One of the keys for reducing the number of processors and sensors in vehicles is to share information. That is going to require more bandwidth, opening the door for FlexRay.
The network is deterministic and fast, with a 10 Mbit/s speed that is 10 times that of CAN (controller area network). But it has seen little commercial usage as engineers instead deployed multiple CAN buses to increase overall bandwidth. Some suppliers expect that to change.
“FlexRay, as it rolls out, will have a significant impact on the way chassis and safety systems are architected,” said Scott Monroe, Systems Engineer at Texas Instruments. “In some ways, it will allow centralization, and, in some ways, it will bring distribution.”
Monroe noted that the bandwidth of FlexRay makes it simpler to put several accelerometers around the vehicle, all sending input to a single control. That centralized controller will make many decisions based on this sensor input, performing tasks that are now done with separate systems.
Determinism may be more of a selling point for FlexRay than its speed. As full vehicle electronics become more complex, ensuring that actions happen at precise times is becoming more important.
“As you go to more centralized architectures, doing things like combining suspension, braking, and stability control, you have a lot of data that needs determinism. FlexRay provides that,” said Marc Osajda, Global Automotive Strategy Manager at Freescale Semiconductor.
On the distributed side, the ability to synchronize signals will make it simpler to have tasks run on different processors. Time-triggered distributed operation makes it possible to employ distributed intelligence and real-time controls.
“The real game-changer coming with FlexRay could be truly synchronized distributed applications,” said Georg Stöger, Product Strategy Manager at TTTech Computertechnik AG. “FlexRay can provide all connected ECUs with a globally synchronous clock, and, based on that clock, you can execute software functions synchronously like you could on a single ECU.”