Fault diagnosis of machines based on D–S evidence theory. Part 1: D–S evidence theory and its improvement

In this paper, conventional D–S evidence theory is improved through the introduction of fuzzy membership function, importance index, and conflict factor in order to address the issues of evidence sufficiency, evidence importance, and conflicting evidences in the practical application of D–S evidence theory. New decision rules based on the improved D–S evidence theory are proposed. Examples are given to illustrate that the improved D–S evidence theory is better able to perform fault diagnosis through fusing multi-source information than conventional D–S evidence theory.