本文選題：星載計(jì)算機(jī)　切入點(diǎn)：三冗余　出處：《復(fù)旦大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：星載嵌入式計(jì)算機(jī)長期工作在宇宙空間輻射環(huán)境中,各種輻射效應(yīng)是導(dǎo)致星載計(jì)算機(jī)在運(yùn)行期間發(fā)生故障的主要原因。各類容錯技術(shù),如冗余加固技術(shù)、機(jī)內(nèi)故障自診斷技術(shù)、系統(tǒng)健康狀態(tài)管理技術(shù)等紛紛被用于星載計(jì)算機(jī)中以提高系統(tǒng)的可靠性,對于保證整個(gè)衛(wèi)星系統(tǒng)的長壽命準(zhǔn)確穩(wěn)定運(yùn)行具有重要意義。本文針對星載嵌入式計(jì)算機(jī)遇到新的可靠性挑戰(zhàn),首先在傳統(tǒng)的具有一活動節(jié)點(diǎn)一冷備份的兩冗余衛(wèi)星系統(tǒng)的基礎(chǔ)上,改進(jìn)并提出了一種具有三個(gè)硬件上完全相同的冗余運(yùn)算硬件結(jié)構(gòu)的星載計(jì)算機(jī)設(shè)計(jì)。這三個(gè)硬件上完全相同的運(yùn)算節(jié)點(diǎn)的主次并不固定,而是通過故障檢測模塊選擇出錯誤概率最低的節(jié)點(diǎn)作為主節(jié)點(diǎn)。并將相對錯誤概率高的節(jié)點(diǎn)進(jìn)行冷藏,使其作為冷備份節(jié)點(diǎn)。這種三冗余結(jié)構(gòu)與傳統(tǒng)的兩冗余冷備份系統(tǒng)相比具備更高的系統(tǒng)可靠性。同時(shí),定期自主選舉表決的策略也增強(qiáng)了系統(tǒng)穩(wěn)定性。論文也開發(fā)了一套具有一定故障預(yù)測能力的故障檢測系統(tǒng),由故障標(biāo)尺和基于故障樹的故障檢測系統(tǒng)組成。因?yàn)閳鲂?yīng)管(metal oxide semiconductor, MOS)器件的閾值在接受了一定量的輻射照射后會發(fā)生漂移,且閾值漂移的幅度與接受的輻射總劑量正相關(guān),所以論文利用這一特性,通過測量MOS器件的閾值電壓漂移程度,來預(yù)測整系統(tǒng)接受到的輻射總劑量,并將輻射總劑量轉(zhuǎn)化為對故障概率的預(yù)測。同時(shí),論文使用基于故障樹的故障檢測方案替代了傳統(tǒng)的基于專家系統(tǒng)的故障檢測方案。相比傳統(tǒng)方案而言,基于故障樹的故障檢測新方案可以更好地利用原有系統(tǒng)各模塊之間的內(nèi)在邏輯聯(lián)系,利用故障樹推理得到的系統(tǒng)故障概率較使用傳統(tǒng)專家系統(tǒng)的方案具有更高的判決正確率。論文中也使用Matlab仿真軟件比較了這兩種故障檢測方法的檢測性能,仿真結(jié)果表明隨著系統(tǒng)邏輯復(fù)雜度的增加,新方案具有更高的故障檢測率。論文還針對目前星載計(jì)算機(jī)系統(tǒng)隨機(jī)存取存儲器(random access memory, RAM)模塊中發(fā)生頻率較高的單粒子多位翻轉(zhuǎn)問題,提出采用具有更高糾檢錯能力的線性循環(huán)碼來替換傳統(tǒng)的漢明碼,并在現(xiàn)場可編程門陣列(Field Programmable Gate Array, FPGA)器件中進(jìn)行編解碼算法實(shí)現(xiàn),充分利用了FPGA器件豐富的存儲資源,完成編解碼算法的快速工程實(shí)現(xiàn)。
[Abstract]:The space-borne embedded computer works in the space radiation environment for a long time, and various radiation effects are the main causes leading to the failure of the spaceborne computer during operation. All kinds of fault-tolerant techniques, such as redundant reinforcement technology, in-machine fault self-diagnosis technology, System health condition management technology has been used in spaceborne computer to improve the reliability of the system. It is of great significance to ensure the accurate and stable operation of the whole satellite system. In this paper, a new reliability challenge is encountered for the spaceborne embedded computer. First of all, based on the traditional two redundant satellite systems with an active node and cold backup, In this paper, a design of spaceborne computer with three identical redundant computing hardware structures is proposed, in which the primary and secondary functions of the same operation nodes are not fixed. Instead, the node with the lowest error probability is selected as the master node by the fault detection module, and the node with relatively high error probability is refrigerated. This three-redundancy structure is more reliable than the traditional two-redundancy cold backup system. The strategy of periodic independent voting also enhances the stability of the system. A fault detection system with certain ability of fault prediction is also developed in this paper. It is composed of fault scale and fault detection system based on fault tree. Because the threshold of metal oxide semiconductors (moss) devices will drift after a certain amount of radiation exposure, and the amplitude of threshold drift is positively related to the total radiation dose. Therefore, by measuring the threshold voltage drift of MOS devices, the total radiation dose received by the whole system is predicted, and the total radiation dose is converted into the prediction of failure probability. In this paper, the fault detection scheme based on fault tree is used to replace the traditional fault detection scheme based on expert system. The new fault detection scheme based on fault tree can make better use of the inherent logical relationship between the modules of the original system. The fault probability obtained by fault tree reasoning is higher than that of traditional expert system. In this paper, Matlab simulation software is also used to compare the detection performance of the two fault detection methods. Simulation results show that with the increase of system logic complexity, The new scheme has higher fault detection rate. This paper also aims at the problem of high frequency single particle multibit flipping in random access memory (RAM) modules of spaceborne computer systems. A linear cyclic code with higher error-correcting ability is proposed to replace the traditional hamming code, and the coding and decoding algorithm is implemented in Field Programmable Gate array (FPGA) devices, which makes full use of the abundant storage resources of FPGA devices. Complete the fast engineering implementation of coding and decoding algorithm.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TP302.7

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 張慶祥,侯明東,劉杰,王志光,金運(yùn)范,朱智勇,孫友梅;靜態(tài)隨機(jī)存儲器單粒子效應(yīng)的角度影響研究[J];物理學(xué)報(bào);2004年02期

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本文編號：1636873