Study On The Method Of Dam Health Diagnosis Based On Conflict Evidence Fusion

The comprehensive safety evaluation of dams and dam groups is essentially a complex problem of multi-source information fusion.The monitoring projects and instruments are numerous and vulnerable to external factors,and the uncertainty of monitoring information is widespread.Although China has made some progress and gratifying achievements in the health diagnosis of single dams,the more mature method is the monitoring mathematical model established for single measuring point and single effect quantitie.And it is seldom involved in the dam group,there is no real dam safety group control technology.In view of this,this paper introduces the D-S evidence theory in the field of data fusion,and proposes a classification and correction algorithm based on information entropy for the measurement and fusion of conflicting evidences,which means the method of dam health diagnosis is extended from single observation point and single effect quantity study to multi-observation points and multiple effect quantities study,and from a single dam to a dam group.And thus a basic system of dams and dam groups for safety monitoring and health diagnosis is preliminarily established.Following are the research results:(1)In view of the possible conflict of evidence in the practical application of D-S evidence theory,the viewpoint of revising the original evidence source is adopted.By introducing information entropy to measure the uncertainty of evidence itself and considering the degree of conflict between evidences,a classification correction algorithm based on information entropy is proposed.(2)The classification correction method based on information entropy is introduced into the field of dam safety comprehensive evaluation.Through the detailed introduction of five parts: the construction of comprehensive diagnostic index system,the establishment of identification framework,basic probability assignment,classification fusion operation and decision reasoning,a dam health diagnosis model based on conflict evidence classification fusion is established,and the dam health diagnosis method is extended from single measurement point and single effect quantity research to multi-observation points and multiple effect quantities study.(3)On the basis of single dam health diagnosis model,by defining the concept of the contribution of dam safety,the safety impact of a single dam on the entire dam group is combined with the conflict and uncertainty of the dam safety information.And in this paper,a method for calculating the subjective and objective weights in accordance with the actual situation of the dam group is proposed,where a multi-level and multi-index dam group health diagnosis model is established,and the research object is extended from a single dam to a related dam group.This paper has some new ideas in the following aspects: Considering the degree of conflict between evidences and the uncertainty of the evidence itself,a classification and fusion algorithm for conflict evidence based on information entropy is proposed.Aiming at the difficulty of Mass function construction of each evaluation index in the process of diagnostic model modeling,the interval distance formula is introduced,and a method of generating assignment function from membership degree is proposed.a method for calculating subjective and objective weights that is more in line with the actual situation of dam group is proposed,which makes the fusion result more reasonable and reliable.Due to the complexity of the comprehensive safety evaluation of dams and dam groups and the limitations of some objective factors,the research result of this paper is only an effective attempt to study the dam safety group control technology.There are still many things that can be done in the future,which requires the joint efforts of domestic and foreign scholars to establish a real dam safety group control technology system.