The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Complex mechatronic systems are becoming more widespread such as in industrial machinery and robotic systems. Detecting faults in such systems proves to be a challenging task due to the multitude of components that are interacting. In this paper, we demonstrate how we use an unsupervised learning technique to detect accelerated wear patterns in complex systems, where wear interactions between components...
Predicting remaining useful lifetime is key to improving operational efficiency, and increasing the reliability of machinery. This paper presents an approach for increasing the accuracy of diagnostics of systems with multiple components. We first discuss a degradation model for systems, where the deterioration process of a component is influenced by the state of deterioration of the other components...
System in which the dynamical behavior evolves based on the interaction between the continuous and discrete dynamics, present in the system, are called hybrid systems. For these systems, maintenance and repair are an increasing part of the total cost of final product. Efficient diagnosis and prognosis techniques have to be adopted to detect, isolate and anticipate faults. This paper presents a novel...
We aged silicone rubber, which is widely used for electrical insulation of cables in nuclear power plants under various conditions. The surface of each sample was measured by an indenter and a scanning probe microscope (SPM) for non-destructive diagnosis. As a result, it has become clear that the surface of silicone rubber becomes hard with the progress of degradation in both cases of thermal aging...
To get the best generator diagnosis possible, multiple tests must be done but this is time consuming and not always possible. For a company such as Hydro-Québec (HQ), operating more than 350 generators, a diagnostic strategy had to be defined to be able to efficiently diagnose generators. A centralized database used in conjunction with a WEB based diagnostic application (MIDA) was developed at its...
The Self-Organizing Networks (SON) concept is increasingly being used as an approach for managing complex, dynamic mobile radio networks. In this paper we focus on the verification component of SON, which is the ability to automatically detect problems such as performance degradation or network instability stemming from configuration management changes. In previous work, we have shown how Key Performance...
The Self-Organizing Networks (SON) concept includes the functional area known as self-healing, which aims to automate the detection and diagnosis of, and recovery from, network degradations and outages. Changes to the configuration management (CM) parameters for network elements could be a cause for degraded network performance and stability; hence, the verification of their effects becomes crucial...
The detection and diagnosis of faults in industrial processes can help to reduce maintenance costs and improve the safety of plant operations. In order to avoid inefficient operation of faulty equipment and minimize the number of unnecessary shutdowns it is important for the operators to have reliable information about the current impact of the fault in the process performance and the future evolution...
Water treeing is a degradation mode of power cable with polymeric insulation. A water tree is composed of small droplets filled with water. As the conductivity in water tree is very high, it leads to dielectric breakdown when it grows up. As inside of the water tree is filled with trap sites, it is polarized with a certain distribution of relaxation time when a DC poling voltage is applied. Although...
This paper proposes a new diagnosis method for aging degradation of insulating paper in power transformers. We took notice of cellulose fibers that suspended in insulating oil in transformers as useful samples for estimating degradation of insulating paper in transformers. The Mahalanobis-Taguchi System was applied for investigating the relationship between degradation and refractive indices of cellulose...
Electronic equipment are subject to degradation and failure as a result of aging and corrosion. Diagnosing to the culprit component, however, is usually not obvious. Some strategic and novel electromagnetic interference (EMI) measurements can be utilized to detect and diagnose failures or degradations. Measuring and monitoring the EMI characteristics of a Unit Under Test (UUT) indicates that the circuit...
This paper focuses on the monitoring of the fuel system of a turbofan which is the core organ of an aircraft engine control system. The paper provides a method for real time onboard monitoring and on-ground diagnosis of one of its subsystems: the hydromechanical actuation loop. First, a system analysis is performed to highlight the main degradation modes and potential failures. Then, an approach for...
This study proposes a numerical model to assess the usability of asset management of electric power apparatuses. A Monte-Carlo technique is employed, so that the various factors, i.e. the wide variety of degradation extent and failure probability among the electric power apparatuses, and the various replacement policy and constraints, etc, can be taken into account. As an example of electric power...
His paper proposes a new diagnosis method for aging degradation of insulating paper in power transformer. We took note of cellulose fibers that are suspended in insulating oil in transformers as samples that could be useful for assessing the aging degradation of insulating paper in transformers. We would like to note that the thermal degradation of insulating paper accompanies the crystallization...
Electric cables in nuclear power plants have to function even after serious events such as a loss-of-coolant accident (LOCA). In most cables, organic polymers that are very sensitive to radiation are used. Nevertheless, much attention was not paid until recently. Under these circumstances, the Japanese government started an extensive research project to examine the degradation behavior of safety-related...
Depending on the diagnostic tool used, the results of the measurements are different diagnostic parameters, e.g. partial discharge (PD) inception voltage, PD magnitudes at different voltages, tangents delta, return voltages, etc. It is also known that aging, degradation, and failure mechanisms are statistical in nature. Moreover, to estimate the time to failure correct statistical interpretations...
This paper proposed a probabilistic model-based approach to diagnose the possible parameters deviations that cause energy system degradation. It is competent for differentiating the deviations that is usually indiscernible in conventional physical model-based analysis. Probabilistic model combines domain knowledge and statistical data. Its diagnostic output provides a probabilistic confidence level...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.