The Design And Implementation Of Fault-tolerant COTS On-board Computer Based On Architecture

In recent years,with the continuous advancement of space technology,satellite technology is also developing with each passing day,and the requirements for satellite performance are constantly improving.As the hub of the entire satellite system,the onboard computer embodies the excellent performance and reliability of the satellite.As far as the traditional on-board computers are concerned,most of them are composed of aerospace-specific devices.The aerospace-specific devices have excellent anti-interference ability and are resistant to radiation hazards in most cosmic spaces with high reliability.On the other hand,traditional aerospacespecific devices are expensive,unstable in supply,and generally lower in performance than COTS(Commercial-Off-The-Shelf).Therefore,COTS devices for on-board computer have gradually become the mainstream trend of on-board computers.Compared with the traditional aerospace-specific devices,COTS devices for on-board computing have gradually become the mainstream trend of on-board computers.How to construct high-reliability on-board computers using COTS-type devices is the opportunities and challenges facing the current on-board computer research.Starting from the advanced schemes and technologies adopted by COTS computers at home and abroad,combined with the actual requirements for the performance of on-board computers,this paper designs a high reliability,high scalability and high practicability faulttolerant system of on-board computer hardware based on COTS devices.The on-board computer hardware fault-tolerant system designed by the subject can divide into a processor board,an arbitration board,an interface board,and a power board.Processor board is the host of on-board computer,and build with the ADSP-SC589 chip as the core;Arbitration board is composed of ARM chip center;Interface board includes many kinds of communication interfaces between on-board computer and external devices(RS485,CAN,etc.);Power board is the main part of on-board computer power system.Because of the poor radiation resistance of COTS devices,it is difficult to use them in onboard computers directly.Therefore,this paper designed a dual-computer redundant faulttolerant system for on-board computer.The system has two identical on-board computer boards.The arbitration board realizes the management of dual-computer working mode and tasks,which greatly improves the reliability and practicability of the system.In addition,the radiationresistant fault-tolerant design has been made for each key part of the on-board computer(such as power supply system,storage system,etc.),so that the on-board computer can meet the actual needs.The project finally completed the PCB drawing of the hardware system of on-board computer,and assembled the prototype of on-board computer.The actual functions and performance of the designed on-board computer are tested and evaluated(including the voltage conversion function test,clock function test and debugging function test,RS485,CAN and AD/DA communication function test).The working mode of the machine has been verified in practice(including anti-single-event latch-up automatic power-off function verification,power forced switching verification and dual-machine switching verification).The verification results show that the design meets the expected functional requirements.The design and research of this subject can directly apply to the actual on-board computer after further improvement,which has great practical significance for promoting the development of on-board computer and even small satellite.