Research On On-board Software Reconstruction Technology Of CubeSat

With the development of space exploration and the diversification of space missions,Cube Satellites with low cost,high functional density,short development cycle and flexible launch mode have become new hotspots in the current space field.With low power consumption,high density integration and various tasks,the On-Board Computer(OBC),which is the core of the integrated electronic system of Cube Satellite,has been put forward higher requirements.While ensuring the reliability of the satellite computer,it is necessary to simplify the hardware design,enhance the function and adaptability of the On-Bord Software(OBS),to meet the diversity requirements of theCube Satellite space mission.The on-line reconfiguration system of OBS proposed in this paper can meet the diverse mission requirements and space networking requirements of satellites through on-line reconfiguration of the OBC system.It can not only improve the reliability ofCube Satellites,but also upgrade their functions.Based on the research and in-depth analysis of on-line reconfiguration technology of OBS at home and abroad,considering the loading mode,starting mode and the working characteristics of the processor,this paper designs the architecture of on-line reconfiguration system for OBS with single-processor based on ARM,and completes the scheme design of embedded operating system and boot Loader.Based on the architecture design of on-line reconfiguration system for OBS,the key technologies of system reconfiguration are deeply studied.Mainly includes:(1)design the hardware architecture,bus interface and storage architecture of OBC based on ARM;(2)complete the storage space allocation technology of OBC adapted to on-line reconfiguration,and realize the switch of multi-version satellite software while having redundancy of software system;(3)design the link script for reconfigurable software generation based on the characteristics of the selected processor and operating system,and the BootLoader program for on-line reconfiguration is implemented.In order to realize reliable and orderly transmission of OBS between satellite and ground,this paper designs a communication protocol based on CSP protocol for on-line reconfiguration system of OBS,and realizes data frame transmission algorithm and response system for on-line reconfiguration.In order to verify the feasibility of OBS reconfiguration technology designed in this paper,a test platform for OBS reconfiguration system is built in the laboratory environment.The feasibility of the on-line reconfiguration system of OBS proposed in this paper is verified through experimental analysis.