Electronic Control Units (ECUs), which are electronic devices, control most of the vehicular operations of a vehicle, such as a car, a truck, a boat, and other such automobiles. A vehicle can have multiple ECUs for various subsystems. For example, a vehicle may include an Engine Control Module (ECM), which is an ECU that may control other ECUs such as ECUs used for transmission, Anti-lock Braking System (ABS), airbags, windows, doors and mirrors, charging systems, Heating, Ventilation, and Air Conditioning (HVAC), etc. According to the designated functions, each ECU collects sensor data directly from sensors and/or communicates with other ECUs in order to coordinate or exchange information. To meet the requirements of inter-ECU communications and to reduce the number of interconnections, vehicle buses are added to a vehicle as the medium for inter-ECU communications.
A vehicle bus is a specialized communications network that interconnects the ECUs inside a vehicle. The ECUs may communicate in a wired manner on the vehicle bus using a communication protocol such as Controller Area Network (CAN), FlexRay, and Ethernet, among others.
Although protocols such as the CAN Bus have been used over the last decade for automotive applications, they are not perfectly robust. Common failures that can sabotage the communications are possible. A well-known issue is called the “babbling idiot” problem, and it occurs when a node suffers functional or component fault and begins to transmit messages onto the bus in an incorrect or unpredictable manner. As a result, an ECU that suffers the babbling idiot issue may consume an abnormal amount of bandwidth and starve other ECUs on the bus.
In addition to an increased demand for reliability, car manufacturers are also facing an increasing demand for network bandwidth for communications among the intra-vehicle ECUs. Such an increased demand for bandwidth is a result of additional features of the vehicle, for example back-up cameras, parking sensors, cruise control, among others. For example, real-time image and video generated by multiple cameras are used for safety features in the vehicle. Furthermore, the infotainment systems on the vehicle are sophisticated and multi-functional, resulting in high data volumes to be processed and transported among ECUs. The data bandwidth of a CAN Bus (500 kbps to 1 Mbps) is, thus, insufficient for such increased demand for intra-vehicle communication. Car manufacturers, in response, have increased the number of CAN buses in the vehicle or introduced high-bandwidth communication protocols like Ethernet. However, the number of CAN interfaces on ECUs limits the number of CAN buses that can be added, while Ethernet, which has the highest bandwidth among all candidates for inter-ECU communications, can only accommodate compressed camera data, which suffers from both high latency and error propagation in time and/or space domain.
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