Operation Status Evaluation of Elevator Based on Cloud Theory and Evidence Theory

In this paper, an evaluation model based on entropy method, cloud model and evidence theory is established to solve the problem that the evaluation result of the elevator operation status is too subjective. By analyzing the primary features associated with the operation status of the elevator, a layered evaluation index system for elevator condition assessment is built. Firstly, the entropy method is used to acquire the constant weights of each indicator, and the variable weight model based on balance function is introduced, in which the constant weights is modified to get the variable weights according to the deviation of actual data and normal value. Then the cloud theory is applied to achieve the conversion between quantitative index and qualitative concept, in which the membership degree is obtained so that index is mapped to each status. Lastly, based on the evidence theory, the index information is fused, and the evaluation results are obtained by the principle of maximum membership degree and reliability criterion. By applying the model we proposed, the example analysis shows that, the model is correct and effective, which could reflect the operation status of the elevator accurately.