On-board Application of FlexRay Bus

With the increasing systematization and complexity of space exploration tasks, the transmission rate and real-time demand of scientific payloads for satellite integrated electronic data transmission are increasing. In response to the fact that the existing on-board buses represented by 1553B and CAN bus cannot meet the growing demand for on-board bus data transmission, this paper carries out the research on the satellite application of the ground-mature high-reliability and high-speed FlexRay bus. First of all, the technical advantages of FlexRay bus applied to satellite integrated electronics are analysed, and the hardware and software design of FlexRay on-board communication node is carried out. The static time is designed and applied to trigger the sending of the corresponding load data, and the dynamic segment of the highest priority event is applied to trigger the sending of regulatory commands, ensuring the system's real-time nature. Taking into account that FlexRay bus is used as an extension or supplement of traditional CAN bus in rail applications, the design realizes the gateway function of CAN bus and FlexRay bus, and adopts the turn-by-turn mapping algorithm to realize the sequential exchange of telegram messages between CAN bus and FlexRay bus. The system is verified by Code Warrior integrated environment, and the feasibility assessment is completed by building the hardware platform with MC9S12XF512. After the BER test, the data are sent and received continuously, and the data of different bus messages in the network are exchanged normally without frame loss or frame error, and the BER is lower than 10^–8. The test results verify the validity and reliability of the design of the on-board FlexRay bus system, which will provide technological support for the subsequent deep-space exploration and space scientific exploration satellites represented by the Chang'E and the Fire Exploration Project.