The FlexRay protocol – A new communications system

Although the FlexRay standard is relatively new, it is already on the road. The 2007 BMW X5 uses a FlexRay bus for its active roll stabilization feature (Dynamic Drive). This is only the beginning. One scenario predicts that the FlexRay protocol will replace the CAN bus, another sees drive-by-wire functionality without the need of a costly mechanical backup. Anyway, FlexRay is the choice of the automotive industry that has teamed up in order to develop a communication system meeting all the industries requirements.

Needs of the automotive industry

Why is FlexRay getting more and more important? Electronics is the key enabler of progress in the automotive sector. Some experts estimate that electronics account for up to 90% of all the innovations that make driving safer, more comfortable, and more fun. This trend is likely to continue since automotive manufacturers keep introducing technical improvements and inventions in the fields of, e.g. safety, reliability, mileage, and comfort. Introducing new advanced control systems, which need perfect collaboration of multiple sensors, actuators, and electronic control units (ECUs), places stringent requirements on the communication technology. These requirements as well as the need for higher data rates, deterministic behaviour, and fault tolerance have not been addressed by prevailing communication protocols, such as CAN.

Joint effort

BMW, Daimler, Freescale Semiconductor (formerly Motorola SPS), NXP (formerly Philips), GM, and Bosch have therefore teamed up in the FlexRay Consortium in order to develop a communication system that is able to meet all the requirements. These ‘Core Members’ have been joined by an abundance of Tier 1s, Tier2, and technology partners, such as EB providing essential support by delivering software and hardware tools.

 

The result: FlexRay is an open and scalable, deterministic and high performance communication technology for automotive applications.

 

• Support of two communication paradigms
  
• Static time driven communication
  
• Dynamic event driven communication
  
• Mixed configuration possible
  
• Flexible extendability, even after deployment
  
• High data rate (10 Mbit/s) and bandwidth efficiency
  
• Scalable fault tolerance
  
• Support of electrical and optical physical interfaces
  
• Support of star and bus topologies
  
• Low overall system cost