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Prognostics and Health Management (PHM) approach based on Physics-of-Failure (POF) builds a close relationship between the reliability and physical structure of products. It enables the assessment and prediction of reliability under actual loading conditions and helps to solve the underlying reliability design problems of electronic products, thus how to identify the failure modes and failure mechanisms...
The analysis method for regression model with unequally spaced time series error is presented, which is based on the relationship between the Green function of continuous system and the autoregression parameters of the time series. The conditional maximum likelihood estimation and exact maximum likelihood estimation of parameters of the regression model with unequally spaced correlated error are discussed...
It has already been realized that the main external factor of MOSFET degradation or deviation from an expected normal condition is the time stress such as work and environment stresses. This paper introduced a real-time damage assessment method for MOSFET based on time stress analysis and failure models. And then, A health state assessment method was researched based on real-time damage information...
Aimed at the characteristics of high-reliability and high test cost of armored equipment chassis, the reliability evaluation based on performance degradation data is proposed. First of all, the performance degradation model is improved by Bayes analysis with small sample, then the formula of reliability is deducted combined with the calculation of posterior distribution. Finally, the validity of this...
As a significant PHM (Prognostics and Health Management) complement, testability is getting much more recognition. But correlations exit between testability parameters, and result in repeated work during testability designing process. First the origin of testability parameters and the effects that are brought by the parameters on design are studied, and some research premises are set up. Then the...
Taking the response data caused by the single event transient effects (SET) simulated by laser test facility and based on the optocoupler for example, this paper adapts sliding FFT method to analyze the response data. Analytical results indicate the method could quickly and correctly implement fault location. Therefore, more time could be saved to take necessary protective measures.
The study on how to use the water medium replacing mineral oil as the lubricating medium of the ship propulsion system, is the high efficient energy-saving of the mechanical transmission system and the frontage of the environmental protection scientific research. The water lubricated rubber stern tube bearing is a very important supporting part of the ship propulsion system, its reliability life will...
Application of electronic devices in automotive industry keeps increasing and adoption of BGA assembly is inevitable in the industry. Vibrating environment in a vehicle provides another hazardous stress to the BGA assembly in addition to thermal one. In this study, random vibration tests on a daisy-chained BGA assembly have been conducted with real-time monitoring of resistance. The change of resistance...
Unmanned Aerial Vehicle ( UAV ) structures are prone to damage during their service lives, caused by abominable environment factors. Its structural health monitoring can be effective in reducing maintenance costs and increasing service life to ensure safe and reliable operation.
The theory and characteristics of the accelerated life test (ALT) and the accelerated degradation test (ADT) is introduced. Based on the discussion about the classification and characteristics of gyroscopes, the accelerated test technology of mechanical gyroscopes and optic gyroscopes is summarized, including test types, stress, accelerated models, failure criterion and some other fundamental test...
Prognostics and Health Management (PHM) is an approach to incipient fault detection, predict impending faults and estimate remaining useful life, which is significant to improve operational readiness and reduce support acquisition costs. Reliability-Centered Maintenance (RCM) is a systematic methodology used to identify the maintenance tasks at the lowest possible cost. After PHM-technology is introduced...
Polar self-organizing map (PolSOM), a novel data visualization algorithm, projects data on a polar map with two variables, radius and angle, which represent data weight and feature respectively. Compared with self-organizing map (SOM), which is a traditional method for dimensionality reduction and data classification, PolSOM visualizes not only the inter-neuron distance, but also the differences among...
During the storage and using process, laser gyroscope zero bias will drift due to influence of temperature, vibration and other environmental factors. This paper uses FMMEA method to analyze the reason for the variation of the laser gyros parameters. Using learning mechanisms of BP neural network to train the model with zero bias data and establish a relationship between zero bias value and the time...
Oil monitoring technology is an effective way to actualize condition based maintenance (CBM) for marine diesel, it can detect earlier failure symptoms, avoidance of fault taking place, it's one of the indispensable diagnostic technology applied in marine diesel's prognostic and health management (PHM). In this paper, according to oil spectral analysis data collected from continuous monitoring, a fault...
In order to improve the safety and economy of civil aviation, based on the Prognostics and Health Management (PHM) System, an Airplane Health Management (AHM) technology is presented in this paper. Although the PHM system contains the abilities of fault detection, fault isolation, fault prognosis and prognosis of the remaining life, extending the time of an aircraft in the air every day is the key...
The relationship between the mean degradation measurement and time is usually monotonically and non-linearly increasing or decreasing. There exists a time point after which the degradation rate rapidly changes. We call this point as degradation change point. It is useful to identify the degradation change point since the probability of a functional failure will quickly increase after an item is used...
Solar cell is one of the core components in photovoltaic systems. The key issue of the photovoltaic system is the photovoltaic conversion efficiency, which not only depends on the conversion efficiency of the semiconducting silicon, but also is closely related to the transmittance of the cover glass. The photovoltaic conversion efficiency will definitely decrease with the attenuation of spectral transmittance...
A paradigm shift is emerging in maintenance strategies from the traditional breakdown and scheduled maintenance to Condition-based Maintenance and Prognostic and Health Management. CBM and PHM technology is required for Aerospace Launch Site Ground Equipments. Among its key technologies, Health Assessment is of great importance. A method of Health Assessment using Mahalanobis Distance is put forward...
According to statistics, landing gears play the major role in the failure of aircrafts. However there are no specifically testing systems currently in use. To solve this problem, this paper presented a landing gear testing system based on PHM technology, designed a framework of both hardware and software of this system. A precise reference can be given to the experimenters by the system embodied the...
The grey model GM (1,1) can be used to predict the data, however, the model usually requires the sequence monotonic. In the prediction of uniform distribution oscillation sequence, using GM (1,1) model directly is not satisfactory. Based on the feature of GM (1,1) model, this paper present an improved algorithm. In the prediction process, we generate residual sequence by raw data firstly, transform...
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