A Modified History Based Weighted Average Voting with Soft-Dynamic Threshold

Voting is a widely used fault-masking technique for real time systems. Several voting algorithms exist in literature. In this paper, a survey on the few existing voting algorithms is presented and a modified history based weighted average voting algorithm with soft-dynamic threshold value is proposed with two different weight assignment techniques, which combines all the advantages of the surveyed voting algorithms but overcomes their deficiencies. The proposed algorithm with both type of weight assignment techniques, gives better performance compared to the existing history based weighted average voting algorithms in the presence of intermittent errors. In the presence of permanent errors, when all the modules are fault prone, the proposed algorithm with first type of weight assignment technique gives higher availability than all the surveyed voting algorithms. If at least one module is fault free, this algorithm gives almost 100 % safety and also higher range of availability than the other surveyed voting algorithms.