A fault diagnosis method based on improved evidence theory and its application
Liu Xi-lian · Zhendong yu chongji · 2013
Aiming at problems that full modification of sensor's evidence information has infirm pertinence and fails to distinguish conflict evidences,a fault diagnosis approach based on improved evidence theory was proposed.Similar evidences and conflict evidences were recognized by means of a conflict evidence criterion.Similar evidences were reserved,while conflict evidences were modified in virtue of a similitude.With this method,the uncertainty of evidence information of sensors was reduced and the effect of conflict evidences on combination results was weakened.Then,combined with a neural network the mapping from a characteristic space to an evidence space was built,and the network output results were used to construct the original evidence with information entropy.Finally,all the evidences were combined with the improved D-S formula.A gear pump's early fault test proved that this new approach has a higher diagnosis precision compared with the neural network method and other combination methods.