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![GPS Receiver Model Component Degradation/Failure: It has been reported in the literature that electrolytic capacitors are the leading cause for breakdowns in power supply system's [9], [10]. The performance of the electrolytic capacitor is strongly affected by its operating conditions, which includes voltage, current, frequency, and working temperature. A degraded electrolytic capacitor cannot provide a low impedance path for the ac current in the output filter of these converters, thus introducing a ripple voltage on top of the desired DC voltage. Continued degradation of the capacitor leads the converter output voltage to drop below specifications, and in some cases it may even damage the converter itself.](profile/Chetan-Kulkarni-2/publication/241195106/figure/fig3/AS:383441926410242@1468431087266/GPS-Receiver-Model-Component-Degradation-Failure-It-has-been-reported-in-the-literature.png)
GPS Receiver Model Component Degradation/Failure: It has been reported in the literature that electrolytic capacitors are the leading cause for breakdowns in power supply system's [9], [10]. The performance of the electrolytic capacitor is strongly affected by its operating conditions, which includes voltage, current, frequency, and working temperature. A degraded electrolytic capacitor cannot provide a low impedance path for the ac current in the output filter of these converters, thus introducing a ripple voltage on top of the desired DC voltage. Continued degradation of the capacitor leads the converter output voltage to drop below specifications, and in some cases it may even damage the converter itself.
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Citations
... Any degradation or faults in the these converter units propagate to the GPS (global positioning system) and navigation subsystems as cascading effects thus affecting the overall operations of the aircraft. Capacitors and MOSFETs (metal oxide field effect transistor) are the key components present in DC-DC converters, which degradations and fail consistently [16]. Some of the more widespread fault effects, such as a ripple voltage surge at the output can cause glitches in the GPS position and velocity output, and this in turn, if not rectified can propagate and distort the navigation resultant solution. ...
This book chapter proposes the use of a model-based prognostics approach for electronics components. Components such as electrolytic capacitors, MOSFETs, and IGBTs are critical components in electronics systems in safety critical domains such as aeronautics, medical, etc. These devices are known to have lower reliability than other electronic components that are used in power supplies of avionics equipment and electrical drivers of electromechanical actuators of control surfaces. The field of prognostics for these is concerned with the prediction of Remaining Useful Life (RUL) of the components and systems. This notion of condition-based health assessment leverages the knowledge of the device physics to model the degradation process, which is then used to estimate remaining useful life as a function of current state of health and future operational and environmental conditions.
... Electronic components such as power amplifiers, power converters, electronic control units, and avionics present substantial challenge to applying PHM methodologies [36,39,41,42]. Normally system engineers use the failure rates of electronic systems from laboratory test data, which is used to define mean time between failures (MTBF) [36]. ...
... Additional modeling constructs to capture the combined discrete-continuous interactions between the systems are also modeled. The details of the work are discussed in [41,91]. We summarize the leading fault conditions from the literature and from select recent accident reports which have been reviewed in [92,93]. ...
... Further, our models for the GPS and INAV units have allowed us to study INAV input faults, such as faults in the GPS receiver and inertial measurement (IMU) units. In this work [41,91] we have included case studies that consider This approach is usually employed when a precise numerical model for the system is not available. For our work we will be implementing the qualitative approach for fault detection and isolation. ...
Avionics systems play a critical role in many aspects of aircraft flight control. As the complexity of these systems increase, the chances of in-flight malfunctions are also likely to increase. This drives the need for Integrated Vehicle Health Management (IVHM) technologies for flight-critical avionics. Studying and analyzing the performance degradation of embedded electronics in the aircraft domain will help to increase aircraft reliability, assure in-flight performance, and reduce maintenance costs. Further, an understanding of how components degrade as well as the capability to anticipate failures and predict the remaining useful life (RUL) can provide a framework for condition-based maintenance. To support a condition-based maintenance and a safety-critical analysis framework, this thesis conducts a detailed study of the degradation mechanisms of electrolytic capacitors, an important component of most electronic systems.
Electrolytic capacitors are known to have lower reliability than other electronic components that are used in power supplies of avionics equipment and electrical drivers of electro-mechanical actuators of control surfaces. Therefore, condition-based health assessment that leverages the knowledge of the device physics to model the degradation process can provide a generalized approach to predict remaining useful life as a function of current state of health and anticipated future operational and environmental conditions.
We adopt a combined model and data-driven (experimental studies) approach to develop physics-based degradation modeling schemes for electrolytic capacitors. This approach provides a framework for tracking degradation and developing dynamic models to estimate the RUL of capacitors. The prognostics and RUL methodologies are based on a Bayesian tracking framework using the Kalman filter and Unscented Kalman filter approaches.
The thesis makes contributions to physics-based modeling and a model-based prognostics methodology for electrolytic capacitors. Results discuss prognostics performance metrics like the median relative accuracy and the alpha-lambda (alpha-lambda) accuracy. We have also demonstrated the derived physics-based degradation model is general, and applied to both accelerated and nominal degradation phenomena. Our overall results are accurate and robust, and, therefore, they can form the basis for condition-based maintenance and performance-based evaluation of complex systems.
... In navigation systems, for instance, degradation and faults in the DC-DC converter power source unit propagate to the global positioning system (GPS) and other navigation subsystems, affecting the overall operations of the aircraft. Capacitors and power metal oxide field effect transistors (MOSFETs) are the two major components that cause performance degradation and failures in DC-DC converters (Kulkarni, Biswas, Bharadwaj, & Kim, 2010). Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output, can cause glitches in the GPS position and velocity output, and this in turn, if not corrected, can propagate and distort the navigation process. ...
This paper presents a model-driven methodology for predicting the remaining useful life of electrolytic capacitors. This methodology adopts a Kalman filter approach in conjunction with an empirical state-based degradation model to predict the degradation of capacitor parameters through the life of the capacitor. Electrolytic capacitors are important components of systems that range from power supplies on critical avionics equipment to power drivers for electro-mechanical actuators. These devices are known for their comparatively low reliability and given their critical role in the system, they are good candidates for component level prognostics and health management. Prognostics provides a way to assess remaining useful life of a capacitor based on its current state of health and its anticipated future usage and operational conditions. This paper proposes and empirical degradation model and discusses experimental results for an accelerated aging test performed on a set of identical capacitors subjected to electrical stress. The data forms the basis for developing the Kalman-filter based remaining life prediction algorithm.
... An avionics system module consists of hardware (power supply, Global positioning system (GPS) receiver, Intertial measurement unit (IMU)) and software (GPS software, INAV -integrated navigation solution) components (Kulkarni, Biswas, Bharadwaj, & Kim, 2010). Switched-mode power supplies are widely used in DC-DC converters because of their high efficiency and compact size. ...
Electrolytic capacitors are used in several applications ranging from power supplies for safety critical avionics equipment to power drivers for electro-mechanical actuators. Past experiences show that capacitors tend to degrade and fail faster when subjected to high electrical or thermal stress conditions during operations. This makes them good candidates for prognostics and health management. Model-based prognostics captures system knowledge in the form of physics-based models of components in order to obtain accurate predictions of end of life based on their current state of health and their anticipated future use and operational conditions. The focus of this paper is on deriving first principles degradation models for thermal stress conditions and implementing Bayesian framework for making remaining useful life predictions. Data collected from simultaneous experiments are used to validate the models. Our overall goal is to derive accurate models of capacitor degradation, and use them to remaining useful life in DC-DC converters.
... In this work we study the degradation effects of electrolytic capacitors on the DC-DC converter systems. In our earlier work [5], [6], we developed models for prognostics studies at the component level, while in [7] a model based DC-DC converter system was studied and fault diagnosis was done by introducing faults in the MOSFETs and Capacitors. ...
... In this work we study the degradation effects of electrolytic capacitors on the DC-DC converter systems. In our earlier work [5], [6], we developed models for prognostics studies at the component level, while in [7] a model based DC-DC converter system was studied and fault diagnosis was done by introducing faults in the MOSFETs and Capacitors. A circuit diagram of a buck-boost converter used for this study is shown in Fig. 1. ...
Failure of electronic devices is a concern for future electric aircrafts that will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. As a result, investigation of precursors to failure in electronics and prediction of remaining life of electronic components is of key importance. DC-DC power converters are power electronics systems employed typically as sourcing elements for avionics equipment. Current research efforts in prognostics for these power systems focuses on the identification of failure mechanisms and the development of accelerated aging methodologies and systems to accelerate the aging process of test devices, while continuously measuring key electrical and thermal parameters. Preliminary model-based prognostics algorithms have been developed making use of empirical degradation models and physics-inspired degradation model with focus on key components like electrolytic capacitors and power MOSFETs (metal-oxide-semiconductor-field-effect-transistor). This paper presents current results on the development of validation methods for prognostics algorithms of power electrolytic capacitors. Particularly, in the use of accelerated aging systems for algorithm validation. Validation of prognostics algorithms present difficulties in practice due to the lack of run-to-failure experiments in deployed systems. By using accelerated experiments, we circumvent this problem in order to define initial validation activities.
... DC-DC power converters are an imporntant part of critical avionic systems. Degraded capacitors affect the performance and efficiency of the DC-DC converters in a significant manner and also impose a risk on instantiating cascading failures on other connected subsystems, such as Global positioning system (GPS) receiver, Inertial measurement unit (IMU)) and software (GPS software, INAV -integrated navigation solution) components [2]. ...
This paper discusses experimental setups for health monitoring and prognostics of electrolytic capacitors under nominal operation and accelerated aging conditions. Electrolytic capacitors have higher failure rates than other components in electronic systems like power drives, power converters etc. Our current work focuses on developing first-principles-based degradation models for electrolytic capacitors under varying electrical and thermal stress conditions. Prognostics and health management for electronic systems aims to predict the onset of faults, study causes for system degradation, and accurately compute remaining useful life. Accelerated life test methods are often used in prognostics research as a way to model multiple causes and assess the effects of the degradation process through time. It also allows for the identification and study of different failure mechanisms and their relationships under different operating conditions. Experiments are designed for aging of the capacitors such that the degradation pattern induced by the aging can be monitored and analyzed. Experimental setups and data collection methods are presented to demonstrate this approach.
... Electrolytic capacitors have become critical components in electronics systems in aeronautics and other domains. This type of capacitors is known for its low reliability and frequent breakdown on critical systems like power supplies of avionics equipment [1]. The field of prognostics for electronics components is concerned with the prediction of remaining useful life of components and systems. ...
... DC-DC converters are studied in this context as a system sourcing power to the global positioning systems and navigation subsystems given that those faults in the DC-DC converters propagate to the navigation systems affecting overall operation. Electrolytic capacitors used as output filters in DC-DC converters cause performance degradation and failures resulting in a ripple voltage surge at the power supply output leading to navigation errors [1]. ...
The focus of this work is the analysis of different degradation phenomena based on thermal overstress and electrical overstress accelerated aging systems and the use of accelerated aging techniques for prognostics algorithm development. Results on thermal overstress and electrical overstress experiments are presented. In addition, preliminary results toward the development of physics-based degradation models are presented focusing on the electrolyte evaporation failure mechanism. An empirical degradation model based on percentage capacitance loss under electrical overstress is presented and used in: (i) a Bayesian-based implementation of model-based prognostics using a discrete Kalman filter for health state estimation, and (ii) a dynamic system representation of the degradation model for forecasting and remaining useful life (RUL) estimation. A leave-one-out validation methodology is used to assess the validity of the methodology under the small sample size constrain. The results observed on the RUL estimation are consistent through the validation tests comparing relative accuracy and prediction error. It has been observed that the inaccuracy of the model to represent the change in degradation behavior observed at the end of the test data is consistent throughout the validation tests, indicating the need of a more detailed degradation model or the use of an algorithm that could estimate model parameters on-line. Based on the observed degradation process under different stress intensity with rest periods, the need for more sophisticated degradation models is further supported. The current degradation model does not represent the capacitance recovery over rest periods following an accelerated aging stress period.
... Degradations and faults of the DC-DC converter unit propagate to the GPS (global positioning system) and navigation subsystems affecting the overall operation. Capacitors and MOSFETs (metal oxide field effect transistor) are the two major components, which cause degradations and failures in DC-DC converters (Kulkarni, Biswas, Bharadwaj, & Kim, 2010). Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this in turn, if not corrected can propagate and distort the navigation solution. ...
A remaining useful life prediction methodology for elec-trolytic capacitors is presented. This methodology is based on the Kalman filter framework and an empirical degradation model. Electrolytic capacitors are used in several applications ranging from power supplies on critical avionics equipment to power drivers for electro-mechanical actuators. These devices are known for their comparatively low reliability and given their criticality in electronics subsystems they are a good can-didate for component level prognostics and health manage-ment. Prognostics provides a way to assess remaining use-ful life of a capacitor based on its current state of health and its anticipated future usage and operational conditions. We present here also, experimental results of an accelerated ag-ing test under electrical stresses. The data obtained in this test form the basis for a remaining life prediction algorithm where a model of the degradation process is suggested. This prelim-inary remaining life prediction algorithm serves as a demon-stration of how prognostics methodologies could be used for electrolytic capacitors. In addition, the use degradation pro-gression data from accelerated aging, provides an avenue for validation of applications of the Kalman filter based prognos-tics methods typically used for remaining useful life predic-tions in other applications.
... An empirical degradation 1 Research Scientist, Prognostics Center of Excellence and AIAA Member. 2 Graduate Research Assistant, Institute for Software Integrated Systems. 3 Professor, Electrical Engineering and Computer Science. 4 Research Scientist, Prognostics Center of Excellence. T model is presented; this model is based on the observed degradation process during the accelerated life test. ...
... Degradations and faults of the DC-DC converter unit propagate to the GPS (global positioning system) and navigation subsystems affecting the overall operation. Capacitors and MOSFETs (metal oxide field effect transistor) are the two major components, which cause degradations and failures in DC-DC converters 3 . Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this, in turn, if not corrected will propagate and distort the navigation solution. ...
A remaining useful life prediction algorithm and degradation model for electrolytic capacitors is presented. Electrolytic capacitors are used in several applications ranging from power supplies on critical avionics equipment to power drivers for electro-mechanical actuators. These devices are known for their low reliability and given their criticality in electronics subsystems they are a good candidate for component level prognostics and health management research. Prognostics provides a way to assess remaining useful life of a capacitor based on its current state of health and its anticipated future usage and operational conditions. In particular, experimental results of an accelerated aging test under electrical stresses are presented. The capacitors used in this test form the basis for a remaining life prediction algorithm where a model of the degradation process is suggested. This preliminary remaining life prediction algorithm serves as a demonstration of how prognostics methodologies could be used for electrolytic capacitors.
... Typically the ripple current effects dominate, and they can have adverse effects on downstream components. For example, in avionics systems where the power supply drives a GPS unit, ripple currents can cause glitches in the GPS position and velocity output, and this may result in errors in the Inertial Navigation (INAV) computations of position and heading, causing the aircraft to fly off course [3,4]. ...
