A Novel History based Weighted Voting Algorithm for Safety Critical Systems

Safety critical systems are the systems which may lead to hazards, loss of lives and great damage to the property if they fail due to errors which may lead to faults. N-Modular Redundancy or N-Version Programming along with the voter is used in the safety critical systems to mask the faults. In this paper different existing weighted average voting algorithms are surveyed and their merits and demerits or limitations are discussed based upon which a novel History based weighted Voting algorithm with Soft Dynamic Threshold is proposed. Experimentation results of the novel voting algorithm for Triple Modular Redundant (TMR) system are compared with existing voting algorithms and the novel voter is giving almost 100% Safety if two of the three modules are error free and giving better results for one error free module. Novel voter is also giving better results for the multiple error conditions with all the modules having errors.