星载系统单故障恢复策略研究

针对指令重试时难以合理选择重试时机和冗余资源问题，并根据星载系统的特点，提出了系统致命失效概率最小的单故障重试恢复策略．该策略以星载系统所有出现的故障均为单故障这一假设为前提，建立了指令重试时间与系统资源备份数及系统的致命失效概率间的关系．通过最小化系统的致命失效概率，可得出在系统资源备份一定时的最佳指令重试时间．同时，若系统存在最大致命失效概率，则可得到在最佳指令重试时系统所需的资源备份数．分析该策略可以发现，星载系统的致命失效概率随着系统的运行期的延长而增大，并且随着错误检测率的提高，星载系统的可靠性增加。

Study on Recovery Strategy from Single Fault in Onboard Systems

Instruction-retry is one of the most simple and effective methods to recover the onboard system from error state. Unfortunately, how to select reasonable retry time and backup resource during the process of instruction retry has not been resolved satisfactorily. A new retry recovery strategy for single fault, which is based on minimizing the fatal failure probability when the system recovers from fault state, was proposed according to the characteristics of onboard systems. On the premise that all faults occurred in onboard system are single fault, the relationships among instruction-retry time, resource backup and the fatal failure probability of the system were given. By minimizing the fatal failure probability, the optimal instruction-retry time can be obtained under the condition that the resource backup is set. Meanwhile, if there is a maximum fatal failure probability, the minimum resource backup can be attained when the instruction-retry time is optimal. After analyzing the strategy, it shows that the fatal failure probability increases with extending of running time of the system, and the reliability of the onboard system increases with increasing of fault detection probability.