Carring II - A Reliable Real-Time Computer Network for Steer-by-Wire

• Applicant: Professor Dr.-Ing. Harald Richter
• Subject Area: Computer Architecture, Embedded and Massively Parallel Systems
• Term: from 2007 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 37822931

In future steer-by-wire systems for cars, the front wheels are steered in real-time by means of two electric motors according to the rotation angle and torque of the steering wheel. There is no mechanical connection between steering wheel and front wheels. This is accomplished by a distributed mechatronic system with a field bus as communication means. However, field busses only have layer 1 and 2 in the ISO 7-layer model. We propose instead a dedicated, fully-fletched, real-time computer network called Carring. Carring exhibits functions from all 7 ISO layers and aims at general intra-car-communications by means of a system's perspective. It will optimally support future x-by-wire driver-assistance systems with steer-by-wire as a special case. Its 4 main goals in comparison to field busses are better reliability and real-time capability as well as better usability and effectiveness. The innovations are in the chosen application itself and in the way we want to achieve the 4 goals for Carring. Carring is based on optical plastic fibers arranged in rings that transmit data with 1 Gbits/s. It has a new medium access with fairness, livelock- and deadlock-avoidance, guaranteed packet latency and high-bandwith efficiency. It allows for automatic car-wide routing, authentication, authorization, common data-exchange format and a new programming model with distributed registers and remote interrupts. By this quality-of-service for data transfers, it is unique in intra-car-communication.

• DFG Programme: Research Grants