C. FlexRay networking standard for motor vehicles serves as the next step beyond CAN and LIN, enabling the reliable management of many more safety and comfort features. FlexRay suits X-by-Wire applications, for example:
• Steering-by-Wire—Typically using electronic control unit .
• Anti-lock brake system (ABS)—Including vehicle stability control (VSC) and vehicle stability assist (VSA) .
• Power train—Controlling an electronic throttle that replaces the current mechanical system.
FlexRay focuses on a set of core needs for today’s automotive industry, including higher data rates than previous standards, flexible data communications, versatile topology options, and fault-tolerant operation. FlexRay thus delivers the speed and reliability required for in-car control systems. The CAN network has reached its performance limits with a maximum speed of 1 Mbps. With a maximum data rate of 10 Mbps available on two channels, giving a gross data rate of up to 20Mbit/sec, FlexRay potentially offers 20 times higher net bandwidth than CAN when used in the same application.
FlexRay also offers many reliability features not available in CAN as flexible configurations, with support for topologies such as bus, star, and hybrid types . Designers can configure distributed systems by combining two or more of these topologies.
To meet diverse communication requirements, FlexRay also provides both static and dynamic communication segments within each communication cycle. The static communication segment provides bounded latency and the dynamic segment helps meet varying bandwidth requirements that can emerge at system run time. The fixed-length static segment of a FlexRay frame transfers messages with a fixed-time-trigger method determined by the longest FlexRay message or Largest transmission delay (up to 2,5 µs) . In addition to operating as a single-channel system like CAN and LIN, FlexRay can operate as a dual-channel system. The dual-channel option makes data available via a redundant network—a vital capability for a high-reliability system. [14][18]