The Research Of DSP Software Redundancy Fault- Tolerant Voting Method Based On Confidence

Commercial-Off the Shelf(COTS) with tolerance design has a broad application prospect in the field of aerospace, especially for near earth orbit satellite system. COTS products can be bought directly in a market, and they are usually classified as commercial components, industrial components and automobile industrial components. However, COTS cannot resist irradiation, which means it should be chosen strictly to build a redundancy fault-tolerant system, so that it can have a higher a reliability and fault-tolerant ability to meet the basic requirement of space exploration missions. Comparing with traditional JANS components, COTS is more flexible in application because of its low price, highly cost effective and easily to get without restriction of import. So the COTS technology is more and more popular in space application.However, to be competent for the space exploration missions, COTS needs to have a fault tolerant architecture. NMR, which uses N modules to deal with the same data and sends results to the software voter to vote the output, is the most common technology. Above all, the reliability and availability of voter is the key to get right results. How to vote accurately and effectively has become a major research direction. Many voting algorithms proposed in software tolerance application have misses, which may lead to big error so that they can hardly meet basic requirement of low price、high ability and reliability. So COTS technology is in sore need to improve the existing software voting method to deal with the problem. In this thesis, considering the weight and confidence of each module, the improving software voting method is proposed and realized.The thesis is completed by using Three Module Redundancy(TMR) as the research object, which is most popular among NMR technology. To test and evaluate the algorithm’s advantages intuitively, the algorithm is compared with traditional voting algorithms. Firstly, the thesis analyses research background and significance, then it tells the advantage of using COTS in space application and researches the present situation of the technology in both China and other countries. Meanwhile, it summarizes achievements and defects. Secondly, the author researches the failure cause and space distribution, and tells the technology of software tolerance in summary, then especially analyses the common structure of tolerance technology, popular voting methods and executing forms. On this basis, the author researches the relevant fault-tolerant design to solve the failure of COTS. Thirdly, the author proposes a highly available solution by improving traditional software voting methods. Finally, the thesis uses the fault injection method to verify the improved algorithm. By testing and simulation, the author gets the answer that the improved algorithm based on confidence is more available and reliable than others by comparing with other algorithms.Above all, the design increases the software redundancy fault-tolerant technical safety and reliability by researching the software fault-tolerant method based on confidence. The thesis provides COTS a new theoretical guidance and technical support.