In chemical processes, fault diagnosis is relatively difficult due to the incomplete prior-knowledge and unpredictable production changes. To solve the problem, a case-based extension fault diagnosis (CEFD) method is ...In chemical processes, fault diagnosis is relatively difficult due to the incomplete prior-knowledge and unpredictable production changes. To solve the problem, a case-based extension fault diagnosis (CEFD) method is proposed combining with extension theory, in which the basic-element model is used for the unified and deep fault description, the distance concept is applied to quantify the correlation degree between the new fault and the original fault cases, and the extension transformation is used to expand and obtain the solution of unknown faults. With the application in Tennessee Eastman process, the result indicates that CEFD method has a flexible fault representation, objective fault retrieve performance and good ability for fault study, providing a new way for diagnosing production faults accurately.展开更多
The technology of diagnostic symptom identification of nonlinear vibration is based on a database of a diagnostic case. This paper defines the periodic degree, quasi periodic degree, and chaotic degree of a Poincare ...The technology of diagnostic symptom identification of nonlinear vibration is based on a database of a diagnostic case. This paper defines the periodic degree, quasi periodic degree, and chaotic degree of a Poincare map, an iterated map, and adopts the image identification theory, so the three states of periodic, quasi periodic, and chaotic running states of a machine can be distinguished. It also defines the variable identity, rotating angle and spread degree. The database of diagnostic case is expressed by means of an access database. The diagnostic symptoms are identified using the difference between the Poincare maps of samples and the fault case.Finally, we demonstrate an identification system of a nonlinear vibration diagnostic symptom of large rotating machinery.展开更多
基金Supported by the National Natural Science Foundation of China （61104131）.
文摘In chemical processes, fault diagnosis is relatively difficult due to the incomplete prior-knowledge and unpredictable production changes. To solve the problem, a case-based extension fault diagnosis (CEFD) method is proposed combining with extension theory, in which the basic-element model is used for the unified and deep fault description, the distance concept is applied to quantify the correlation degree between the new fault and the original fault cases, and the extension transformation is used to expand and obtain the solution of unknown faults. With the application in Tennessee Eastman process, the result indicates that CEFD method has a flexible fault representation, objective fault retrieve performance and good ability for fault study, providing a new way for diagnosing production faults accurately.
文摘The technology of diagnostic symptom identification of nonlinear vibration is based on a database of a diagnostic case. This paper defines the periodic degree, quasi periodic degree, and chaotic degree of a Poincare map, an iterated map, and adopts the image identification theory, so the three states of periodic, quasi periodic, and chaotic running states of a machine can be distinguished. It also defines the variable identity, rotating angle and spread degree. The database of diagnostic case is expressed by means of an access database. The diagnostic symptoms are identified using the difference between the Poincare maps of samples and the fault case.Finally, we demonstrate an identification system of a nonlinear vibration diagnostic symptom of large rotating machinery.
