Design And Research On Core Units Of Flight Control Computer Based On FlexRay Bus

Flight control computer(FCC) is the core part of the flight control system, which carries the complex tasks such as flight control, control law calculating, equipment management, etc. With the increase of the complicated missions of unmanned aerial vehicle flight, the performance of FCC has dropped into a bottleneck: the margin of processing capacity is gradually reduced; the interfaces of sensors become deficient; the internal bus load is heavy; efficiency and reliability of communication cannot meet the needs of FCC. In this paper, the core units and key technology about FlexRay bus for FCC were designed and developed to break the constraints above.Firstly, considering the structure of distributed FCC, the research status of distributed redundant FCC and FlexRay bus, the design schemes of the central processing unit and the serial input and output unit were proposed separately, in order to solve the problem of insufficient processing performance of FCC units. This paper also introduced the basic communication mechanism and the redundancy strategy of FlexRay bus, which aimed at easing the problem of the internal information transmission capability for FCC.Secondly, according to the idea of modular design, the design of the central processing unit based on MPC8280 and the serial input and output unit based on FPGA were accomplished, which improved the performance of processing and communication, also meet the demands of flight control system. Then, analyzed the data and communication needs of internal bus in the sample distributed flight control computer, and designed the communication protocol of FlexRay bus. Taking the bus load, reliability and accuracy of communication into consideration, the detailed design of the redundancy management strategy of FlexRay communication was carried out.Finally, the basic test and system integration test schemes were designed to verify the design above. The results showed that the design of core units, FlexRay bus communication and redundancy management can meet the requirements of design.