Reliability Design And Implementation Of Coarse Pointing System Of Satellite Laser Communication

There are a large number of high-energy particles in the space environment that thesatellite laser communication terminal system works in. Because of the impact ofhigh-energy particles, electronic components will produce kinds of space radiationeffects, such as total ionizing dose (TID), single event effect (SEE),etc. The satellitelaser communication terminal system goes wrong likely due to these space radiationeffects. This paper studies that how to improve the reliability and guarantee long-lifeuse of the system. The satellite engineering reinforcement technique against radiationand the functional design and realization of the coarse pointing system of satellite lasercommunication terminal are studied in the paper. Besides, the paper mainly analyzes afault-tolerant design scheme of coarse pointing system, and the system reliability isanalyzed by using markov model.Radiation-hardened reinforcement is the primary measures to improve thereliability of the coarse pointing system. This article introduces the selection rules ofelectronic components in satellite engineering, analyzes and designs the derating useand protection circuit for electronic components. Moreover, the shielding reinforcementon the casing layer and device layer is studied in the paper.The coarse pointing system is an important part of the whole satellite lasercommunication terminal system. This paper briefly analyzes the capture mechanism,scanning method and the working process of satellite laser communication system.Detailed function design for the coarse pointing system is studied and realized from twoaspects of hardware and software, mainly includes CPU control module, serial portcommunication module, D/A conversion module, power supply module, timing signalmodule, etc.Redundancy fault-tolerant design is the key technology to ensure the functionalreliability and long-life use of the coarse pointing system. The coarse pointing system isdivided into the main control unit, control unit, encoder decoder unit and the drive unitaccording to the function. This paper proposes a fault-tolerant architecture of dual-module hot standby in combination with cold standby at the level of unit module,according to the characteristics of functional independent relatively for each unit. Themain control unit of coarse pointing system is responsible for the switch of master orslave module and has high real-time demand. So it adopts the mode of dual-module hotstandby, while the rest of the three units adopt the mode of dual-module cold standby.Within the fault-tolerant architecture above, fault-tolerant design methods are detailedstudied at various stages included fault detection, fault location, switch of master orslave module and system reconfiguration, in the aspect of hardware. And commonly used fault-tolerant technologies is discussed including error detection and correction(EDAC), three-module redundancy, etc, in the aspect of software. Based on the aboveanalysis and research, the paper conducts fault simulation using PCB boards of the maincontrol unit of coarse pointing system. Finally, this article analyzes the reliability foreach functional unit of coarse pointing system using the theory of markov model, andfor the whole coarse pointing system on this basis.