Testbeds of a hybrid-ARQ-based reliable communication for CANs in highly electromagnetic environments

While controller area networks (CANs) supplies noise resistance mechanism based on detection and retransmission. when it comes to the modern electronic vehicles (EVs) and hybrid vehicles (HVs), the noise level caused by high voltage switching in DC-DC converters could be very large and thus the performance of the CAN protocol would be significantly reduced. In this paper we propose an application layer-based hybrid ARQ protocol for CANs. The proposed protocol consists of automatic repeat request (ARQ), forward error correction (FEC), and HALT modes, and selects an appropriate transmission mode according to the level of the noise. The experimental results by using a prototype system implemented on real CAN nodes show that our protocol can adaptively switch its mode according to the noise level, and also that the proposed scheme can effectively suppress the bus utilization rate of CAN network cause by retransmission under highly electromagnetic environments.