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Virtual maintenance based on virtual reality has been developed recent years, yet the relation between qualitative analysis and quantitative analysis has not been built. In this paper, a calculation method of operational domain of virtual maintenance based on convex hull algorithm is proposed. First, a hierarchical skeleton mathematical model based on the physiological characteristics of human skeletal...
In this paper, an optimal selection method of the test points in the field of test-ability design is provided. Based on bacterial foraging algorithm and improved particle swarm optimization algorithm. This proposed method, which is named SC_BFO (Swarm Cooperation Bacteria Foraging Optimization), is applied in optimization selection of test points. Firstly, in order to ensure the availability of the...
This paper puts forward a testability modeling method for analog circuit fault prediction. It firstly gets the grey correlation entropy of each test point in the analog circuit. Then it treats each grey correlation entropy as a correlation coefficient to form the dependency matrix of testability. After that, according to the dependency matrix we get, the paper uses the method of PSO (Particle Swarm...
This paper provides an optimized PSO (Particle Swarm Optimization) in testability design for complex avionics. It firstly proposes a nonlinear time-varying adjustment strategy which can adjust change rates of learning factors c1 and c2 through variables a and b. Then it simulates different pairs of a and b, aiming at finding out much better change rates of learning factors to optimize the PSO. After...
Prognostics and Health Management (PHM) is a technology to monitor the equipment status and predict impending faults. It is used to predict the potential fault and provide fault information and track trends of system degradation by capturing characteristics signals. So how to detect characteristics signals is very important. The select of test point plays a very important role in detecting characteristics...
This paper proposed an optimization algorithm based on information flow testability modeling to optimize the selection of TPs. This method is an improved particle swarm intelligence algorithm based on the traditional fuzzy particle swarm algorithm. And improvements were made according to the features of dependence matrix. Software simulation was made to proof this methods.
This paper provides a comprehensive validation method of PHM system's diagnostics and predictive capability. It consists of five steps: including the parameter selection of PHM comprehensive validation; the sample database creation of PHM comprehensive validation; the samples processing methods of PHM comprehensive validation; the sample injection method of PHM comprehensive validation; the assessment...
This paper is based on the engineering requirements of intelligent fault diagnosis technology, and designes the information-enhanced fault diagnosis system for avionics power supply module. Firstly, we designed the framework of the system, gave the information that needed for fault diagnosis and the way to get it. Then, the fuzzy neural network model was established which combines the neural network...
In this paper, aiming at some difficulties such as in-flight fault detection and fault isolation of aviation integrated computer system for its complex structure and function, an intelligent BIT design method of aviation integrated computer system, which combining integrated BIT and information-enhanced BIT, has been given after analyzing the research content and development of intelligent BIT. The...
De-noising and extraction of the weak signature are crucial to fault diagnostics in which case features are often very weak and masked by noise. The wavelet transform has been widely used in signal de-noising due to its extraordinary time-frequency representation capability. In this paper, wavelet decomposition-based de-noising method is employed for fault feature extraction of hydraulic pump. The...
Considering the drawback of the big error when using fixed threshold in fault diagnosis for hydraulic servo system, many factors that may affect the fault threshold are analyzed. By integrating the key factors in threshold model, such as modeling error, random disturbance, input instructions, system current status and etc, an adaptive threshold scheme for fault diagnosis is proposed in this paper,...
Fiber optic sensors have been used widely during the past two decades. Demodulation module is very important in the system. The performance of the system may be suffered significantly if the demodulation algorithm is not properly carried out. The demodulation algorithm for a Mach-Zehnder interferometric fiber acoustic sensor with 3times3 coupler is investigated in this paper. The mathematical expression...
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