Junyou Shi

Research on component-level health quantitative assessment based on SVM algorithm for analog electronic circuits

On the basis of the study of the analog electronic circuit theory, a component-level health quantitative assessment model based on support vector machine algorithm was proposed in this paper. This paper divided the health condition of analog electronic circuits into health status, sub-health status and failure status, then the particle swarm optimization (PSO) was applied on the optimization of support vector optimization parameters. In the end, this paper builds the component-level health quantitative assessment model based on support vector machine algorithm.

Application of fault dictionary diagnosis methods in the testability field

Fault dictionary diagnosis methods is widely used in Testability field. Through looking up the fault table, fault dictionary can detect and isolate the fault of UUT. The principle of fault dictionary is: First of all, perform all the tests to get the test results for each test logic point (usually expressed as 0/1) and form state characteristics, Then one by one query fault dictionary to determine whether the state is consistent with the characteristics, if consistent, the status of the UUT corresponds to a fault condition. Based on the method mentioned above, use pspice to simulate a five amplifier circuit in fault states. Through the analysis of the simulation results, we can prove the fault dictionary method is effective and accurate.

Dynamic Bayesian networks in electronic equipment health diagnosis

Bayesian network is the main research method in the field of artificial intelligence for uncertainty problem representation and processing of and health grading evaluation is one of the important technology in health management. Through the analysis of different models and study methods of Bayesian theory, combining the characteristics of the three-state dividing of system, the three states of dynamic Bayesian network health evaluation method is put forward, which calculates the dynamic Bayesian network using the hidden Markov model. Then EM algorithm and CRLA algorithm for dynamic Bayesian networks parameter learning are studied. Finally, based on Pspice simulation software and the DBN software toolbox of Matlab, the three-stage amplifier circuit Bayesian evaluation model of the three health states is built, and the corresponding application instructions and results are obtained. Thus the correctness and feasibility of the related methods put forward in this paper are verified.

An application of systemic prediction evaluation parameters for neural network remaining useful life predictions models

PHM (Prognostic and Health Management) is a new concept, which is to ensure the normal operation of the complicated system, to achieve its functionality and reliability better. In this situation, the remaining useful life (RUL) prediction has aroused more and more concerns. Although the life prediction methods are many, there are not a set of systemic of evaluation parameters to evaluate the accuracy of the prediction method. The existing parameters have different limitations. Therefore, due to the shortage of the existing parameters, this paper presents the systemic prediction evaluation parameters to evaluate the prediction ability of the method. Then, some parameters are applied to the BP neural network in a power supply system of the evaluation.

Application of fuzzy diagnosis to the voltage regulator module based on temperature

Fuzzy diagnosis method is easily and widely used in fault diagnosis field. It provides an effective approach to quantify qualitative indicators. The temperature variation and failure cause of the voltage regulator module (VRM) in a power processing printed circuit board (PCB) have fuzzy relation. The fuzzy information is applied to the fault diagnosis of the VRM. The characteristics of the temperature variation define member function with the inverted trapezoidal function. The fuzzy relation matrix is determined by evaluations, and a new fuzzy operator is used to calculate the evaluation matrix. The result of application to VRM state that the fault diagnosis method is effective. The fuzzy relation matrix is enriched and validated in the process of the fault diagnosis.

A design of simulation and analysis platform of BIT false alarm considering stochastic characteristics

Base on a comprehensive analysis of causes and classification of BIT false alarm, the stochastic characteristics mechanism of BIT false alarm is summarized, the parameters for BIT false alarm assessment is proposed, and the breakthrough of the method of BIT false alarm caused by which the noise analog and the research of BIT modeling and simulation methods considering stochastic characteristics. Therefore, the design of interface profile of BIT false alarm considering stochastic characteristics is completed. According to the methods of simulation, modeling and assessment of BIT false alarm considering stochastic characteristics, the simulation platform of BIT false alarm randomness is designed, combined with typical BIT false alarm circuit simulation cases in addition to provide technical support to apply for the practical application of engineering tools According to the existing simulation analysis of BIT false alarm circuit, considering the description of randomness factors and stochastic characteristics considering interference, study the BIT detection threshold randomness modeling, the methods of simulation considering the randomness of BIT, the design of false alarm simulation profile considering stochastic characteristics are achieved. Moreover, the process of working on the simulation platform is completed into designing framework and the functional modules in accordance with completing the design of input and output data structure, and the overall algorithm of simulation platform, through the communication interface of Matlab, Orcad and Labview joint simulation to complete the final design of each function, and the randomness of BIT false alarm.

A method of testability optimization based on BIT working mode considering the basic reliability

Testability optimization is an important part of testability design. In the past, testability optimization design often neglects the correlation between testability and reliability and does not pay much attention to the influence of system reliability. Considering such circumstance, this paper studies the impact of the basic reliability of the system and the Built-In Test (BIT) working mode. Different optimization models for the testability design are established. A method of testability optimization based on BIT working mode considering the basic reliability is proposed. The fiber-optic inertia system is taken as an example to verify the method. The simulation proves the applicability and effectiveness.

General models for system reliability and testability optimization considering multi mission profiles

Different kinds of operating environment and multiple mission conditions result in dynamic mission definitions, stages and profiles of complex systems like avionic systems in airplanes. A complex system usually consists multiple parts, units or subsystems which perform limited functions and are hardly under operation for all time. Based on such circumstances, traditional system reliability and testability (R&T) analysis may incur incompleteness, eventually resulting in testability optimization deviation. To solve this problem, six novel R&T integrated optimization models considering multi mission profiles and multi systems are introduced in this paper to improve testability design for adaptability in multi-mission situations: R&T optimization model for serial stationary mission profiles, parallel stationary mission profiles, stochastic serial mission profiles with exclusive mission stages, stochastic serial mission profiles with correlative mission stages, independent parallel mission profiles and identical parallel mission profiles. The proposed models are defined and designed based on normal working conditions. The validity and effectiveness of the given models can be verified when specific meanings of parameters is given according to real problems.

An embedded diagnosis semi-physical system of typical avionics based on LabVIEW and MATLAB

Considering that the physical demonstration is difficult to implement in the real test experiment, and the complete simulation verification is difficult to satisfy the requirement. This paper designs a semi-physical demonstration system based on LabVIEW and MATLAB, and realizes the synchronous diagnosis of the state graph simulation model and hardware. The design principle of the slave computer and the host computer is introduced in detail. The embedded diagnosis semi-physical system of typical avionics is taken as an example to partly implement the demonstration system, and the result proves the applicability and effectiveness.

An extended testability modeling method based on the enable relationship between faults and tests

To improve the accuracy of testability modeling, the paper proposes an extended testability modeling method based on FTE (the enable relationship between faults and tests). The characteristics of FTE are analyzed, and corresponding mathematical definition is given. Besides, the graphic modeling method of the extended model of testability considering FTE is designed, and the acquisition method of the diagnosis matrixes considering FTE is also proposed. At last, using the traditional modeling method and an extended testability modeling method based on the enable relationship between faults and tests to model of the laser inertial navigation system.