Applied Mechanics and Materials Vols. 241-244

Abstract: Designed a sort of IETM fault diagnosis system based on PMA, which includes maintenance guiding pattern, fault auto-diagnosis pattern and tele-maintenance cooperative support system based on expert system. Enrich and strengthen fault diagnosis function of PMA and has a certain significance to broaden.

Abstract: This paper proposes a new integrated diagnosis inference system based on the framework of C Language Integrated Production (CLIPS) and Bayesian networks (BNs). Utilizing the fault modeling, model verification, model analysis, model conversion and knowledge base generation, this system deals with the conversion from the fault flow diagram to knowledge base, the fault tree to BNs, simplifies the method for knowledge base construction and fault modeling, and enhances the methods to obtain the knowledge for intelligence fault diagnosis system.

Abstract: A general framework of hydraulic fault diagnosis system was studied. It consisted of equipment knowledge bases, databases, fusion reasoning, knowledge acquisition and so on. The tree-structure model of the fault knowledge was established based on fault hierarchy and logicality. Fault nodes knowledge was encapsulated by object-oriented technique. Complete knowledge bases were made including fault bases and diagnosis bases. It could describe the fault positions, system structure, cause-symptom relationships, diagnosis principles and other knowledge. The results show that the methods are effective.

Abstract: To establish an international standard on the electronic testing method for raw silk, the interlaboratory comparison tests of the electronic testing method for raw silk are done. Five lots of soaked silk are sampled and tested by four machines of the same type in four labs, 13 items including the defects and evenness information of each lot of silk are measured. The analysis of variance and multiple comparison procedure are used to find whether there exist significant differences among the four machines; and the result shows that there are no significant differences among the machines in testing these items except for the item of IPMe by optical sensor. The reason for the difference is analyzed, and the measure for dismissing the difference is proposed.

Abstract: On-site experience suggests the possibility of condensation of the moisture in Current transformers (CTs) with initial moisture content lower than the Chinese National Standard. In order to verify such possibility, the relationship between moisture content and ambient temperature in a typical 110 kV CT is studied. The positive correlation of ambient temperature and moisture content without current flow is clarified, and the relationship of moisture content and current RMS value is studied. Increase in current results in increase of moisture content, and the longer the duration of operation, the larger the moisture content. The possibility of frost condensation of the moisture with sharp ambient temperature decrease has been confirmed with initial moisture content lower than the Chinese National Standard.

Abstract: A VPRS (Variable Precision Rough Sets) data model is created according to measured signals collected from the bridge erecting machine safety monitoring system, and the signals acquired from many different sensors are theoretically deduced and discussed on this model. Combining with classificatory error parameter and approximate dependence degree, the relationship between signals and noises is analyzed to fulfill Multi-sensor Information Fusion theory. Finally the order of validity about the multi-sampling points is obtained, which can used to direct localization of sensors.

Abstract: The method of how to select target equipments in a whole plant for a PdM program is proposed in the paper. A set of evaluation standards using criticality analyzing approach are established. This method is applied in many plants and is verified with the actual condition of plant requirement. The evaluation results fit for the criticality of all plants and will be different in different plants because of service and functional role played even for the same type machine.

Abstract: ADS40 is the first commercial three line scanner(TLS) Airborne Digital Sensor developed by LH Systems jointly with DLR and launched in 2000.The unique hardware design and dataset processing workflow of ADS40 bring challenges to traditional calibration theory and methods. Considering the imagery acquirement and interior orientation methods of ADS40, the ADS40 test field calibration using posteriori compensation method is proposed: An analysis is made to the systematic error of ADS40’s cam file. A set of first order bivariate polynomial functions is developed to fit the systematic error, and the solution method is deduced. With the practical ADS40 dataset, a set of experiments is done, and the experimental results demonstrate the effectiveness and feasibility of proposed method.

Abstract: It was concluded by comparison of 60 sites of elevation data from SRTM-DEM and field measuring in Qinling-Dabashan area that there was a close correlation between them with a correlation coefficient of r2=0.9989 and a mean error of 18.22 meters. It was demonstrated that SRTM-DEM could present undulating terrain better in the region. The errors of SRTM-DEM in the region have nothing to do with slope, degree of shelter or terrain fragmentation. They belong to accidental errors but not systematic errors.

Abstract: For effectively analyzing electric power faults, exactly identifying failure type, and highly providing disposal measure, depending on PSO (particle swarm optimization) algorithm, a PSO-FCM (particle swarm optimization-fuzzy c-means) algorithm was constructed by the FCM improvement of fuzzy clustering to avoid get in local optimal state. On this basis, an electric power system fault diagnosis method was established by means of PSO and FCM. Finally, this method was validated by an example. Consequently, this method can intellectively diagnose and identify the fault of electric power system, and can provide a new approach to stably operation in electric power system.