Space Embedded Small Satellite Software Fault-tolerant System Design And Test Research

Relevant studies on the design of micro-satellite embedded software high fault-tolerance and high reliability and the method for testing and evaluation of software fault-tolerance mechanisms (FTMs) are presented in this dissertation. The software quality model in the space condition is discussed and researched in detail at first. After the comparison of lots of software quality models, a model that fits the needs of project managers is introduced. According to other models, This model is dynamic, not static, in the fact that it allows the production of multiple snapshots of project status across the development, and uses a broad range of measures, since it contains goals, attributes, and metrics for both software products and development processes. This model is also comprehensive, starting with specifying goals through presenting the results. In order to fit the space condition, the ability of fault-tolerance is used to measure the software quality. Subsequently, the design method of fault-tolerance is discussed. According to the needs of high function density and low volume and mass of modem micro-satellite, not only hardware fault-tolerance but also software fault-tolerance are needed. In order to improve the reliability and ability of fault-tolerance of CX- 1 micro-satellite, hardware fault-tolerance technology such as WDT, EDAC, multi-computer system etc. and software fault-tolerance technology such as NYP, Recovery Block, Forward and Backward Recovery etc. are used together. Fault-tolerance testing is a classic emphasis of evaluating the effection of software fault-tolerance. Testing case generation is one of three key processes of software fault-tolerance testing. And this paper brings out one method to optimize the fault testing case based on Fault Tree Analysis (FTA) and GA (Genetic Algorithm) software testing case generation strategy. Fault injection (FL) is a powerful method for the testing and evaluation of fault-tolerance mechanisms (FTMs), which may widely be used during all phases of the development of fault tolerant computer systems. A single event phenomenon fault injection (SEP-FL) model based on event-driven is presented in this paper, and SEP-FL algorithm is discussed in detail. After the comparison of lots of fault injection tools, the aerospace SEP Fault Insertion System based on injecting fault both in the memory and through the bus is introduced in the following. The structure and functions of FIS (Fault Injection System) are firstly introduced. On the basis of expansibility and universality, the study is concentrated on the key implementation technology in Fault Injection Unit. The practical results show that the FIS is low cost, high universality, fully dynamically and real-timely injected. Another problem that must be studied in the software fault-tolerance testing is SRTP (Software Reliabi1ity Testing PlatfOrm). Because of the specia1 needs of theembedded software, SRTP is very imPortant for the morden micro-sate1liteembedded software testing. A S&T (Simulation and Testing) platform fitted to CX-1micro-satellite is introduced in this paPer S&T platfOrm is designed by mixedprototape, which can improve the system's flexibility and low the cost. Thesimulation models such as dynamics simulation, energy system simulation and GPSsimulation are discussed in detail. As a DIS (Distributed Interactive Simulation)system, the problem of time syncbIonization is a key technology and is discussed inthis paper Finally one simPly software time sgnchronization method with highprecision is proposed and realized. S&T platfOrm is very significant for self testingof the com...