Research On Microkernel Real-time OS Of Micro-Satellite And Method Of Fault Tolerant

Having the advantage of light weight, small size, and low power, Micro-satellite can work in space environment of low temperature and high radiation without human interferes. Relevant studies on the design of micro-satellite embedded real-time fault tolerantand regroupable operating system and further research in relevant fields of software engineer are presented in this dissertation. After the comparison of lots of operating system models, micro-satellite operating system design philosophy based on microkernel is introduced at first. This model decrease the inter-module calls sharply, thereby, assure the high reliability and extensibility from the structure.Subsequently, the scheduling strategy of the system processors is discussed. Afterstudying time driven and event driven and considering the specific demands of Micro-satellite operating system, time-event driven preemptive scheduling strategy based onmessage processing is chosen to meet the system demands. This strategy synthesis thebenefits of both event driven and time driven, could lower the response time ofcritical task and avoid losing control when a suddenly overload appears.Furthermore, Based on the analysis of the main obstacle of fault-tolerant real-time system, thispaper focuses the view to the research of fault-tolerant real-time scheduling, In addition, the author present a universal fault-tolerance real-time scheduling algorithm, which can schedulevarious tasks. This paper proves the correctness of those algorithms, give its schedulability bound and analyze its performance. Then, based on real-time operation system VxWorks, the paper discusses the design of fault-tolerance scheduling module and the achievement of the LP-FT fault-tolerance scheduling algorithms. The results show that time and performance cost of fault-tolerance scheduling can satisfy requirements of real-time system.Finally, the author present the method of coding fault-tolerant to conquer the fault mode in aerospace, and this method was tested by Modelsim.