Diagnosis methodology based on deep feature learning for fault identification in metallic, hybrid and ceramic bearings

Scientific and technological advances in the field of rotatory electrical machinery are leading to an increased efficiency in those processes and systems in which they are involved. In addition, the consideration of advanced materials, such as hybrid or ceramic bearings, are of high interest towards high-performance rotary electromechanical actuators. Therefore, most of the diagnosis approaches for bearing fault detection are highly dependent of the bearing technology, commonly focused on the metallic bearings. Although the mechanical principles remain as the basis to analyze the characteristic patterns and effects related to the fault appearance, the quantitative response of the vibration pattern considering different bearing technology varies. In this regard, in this work a novel data-driven diagnosis methodology is proposed based on deep feature learning applied to the diagnosis and identification of bearing faults for different bearing technologies, such as metallic, hybrid and ceramic bearings, in electromechanical systems. The proposed methodology consists of three main stages: first, a deep learning-based model, supported by stacked autoencoder structures, is designed with the ability of self-adapting to the extraction of characteristic fault-related features from different signals that are processed in different domains. Second, in a feature fusion stage, information from different domains is integrated to increase the posterior discrimination capabilities during the condition assessment. Third, the bearing assessment is achieved by a simple softmax layer to compute the final classification results. The achieved results show that the proposed diagnosis methodology based on deep feature learning can be effectively applied to the diagnosis and identification of bearing faults for different bearing technologies, such as metallic, hybrid and ceramic bearings, in electromechanical systems. The proposed methodology is validated in front of two different electromechanical systems and the obtained results validate the adaptability and performance of the proposed approach to be considered as a part of the condition-monitoring strategies where different bearing technologies are involved.Peer ReviewedPostprint (published version

A review of electrostatic monitoring technology: The state of the art and future research directions

Electrostatic monitoring technology is a useful tool for monitoring and detecting component faults and degradation, which is necessary for system health management. It encompasses three key research areas: sensor technology; signal detection, processing and feature extraction; and verification experimentation. It has received considerable recent attention for condition monitoring due to its ability to provide warning information and non-obstructive measurements on-line. A number of papers in recent years have covered specific aspects of the technology, including sensor design optimization, sensor characteristic analysis, signal de-noising and practical applications of the technology. This paper provides a review of the recent research and of the development of electrostatic monitoring technology, with a primary emphasis on its application for the aero-engine gas path. The paper also presents a summary of some of the current applications of electrostatic monitoring technology in other industries, before concluding with a brief discussion of the current research situation and possible future challenges and research gaps in this field. The aim of this paper is to promote further research into this promising technology by increasing awareness of both the potential benefits of the technology and the current research gaps

A Framework and Breakdown of Health & Usage Monitoring systems for Aircraft Applications

Asset Management strategies are converting from a reflective/reactive maintenance to preventive and predictive maintenance methods. With the increasing need for higher safety standards and to reduced operational and maintenance costs, the need for methods to diagnose and predict the occurrence of failure is becoming an imminent requirement. With the application of present day technology and non-destructive evaluation and monitoring techniques, this report proposes a framework based on which active diagnosis of the condition of a unit (vehicle/structure) can be monitored towards providing better maintenance practices.In the world of Rotorcrafts Heath and Usage Monitoring Systems (HUMS) have started to catch traction due to the higher safety standards it provides by continuous awareness of internal working and the reduced maintenance and replacement costs assured by this system. A well developed comprehensive system designed for a specific aircraft platform would be able to analyze critical failure modes, analyze usage and conditional data of the entire structure (extrinsic and intrinsic) and provide a prognostic knowledge to the user/operator and owner of the units.Within approved safety margins and threshold levels, a HUMS system can provide cost saving by alerting the maintenance crew when the optimal time to change parts are, avoiding underusing or overusing a component, and also to unexpected failures.This thesis attempts to provide a framework of analysis methodologies and logic flow for a user, engineer, designer or operator to establish a comprehensive HUMS system on a unit so as to ensure the full utilization of present technology. Here Usage-Based Monitoring (UBM) data and Condition-Based Monitoring (CBM) data are collected through sensor networks placed strategically through a Functional Hazard Assessment (FHA) regiment in order to provide the end user and maintenance staff accurate and immediate information on the diagnostics and prognostics of the unit. This allows for better maintenance scheduling, lower labor costs, lower inventory costs and above all safety.Soon an established HUMS system will be mandatory on most large scale-expensive commercial products such as aircrafts, ships, bridges, etc. so as to ensure the safety of its users and in the long run allow the owners to benefit from the inevitable financial savings that it promises.M.S., Mechanical Engineering and Mechanics -- Drexel University, 201

30th International Conference on Condition Monitoring and Diagnostic Engineering Management (COMADEM 2017)

Proceedings of COMADEM 201

Time domain analysis of switching transient fields in high voltage substations

Switching operations of circuit breakers and disconnect switches generate transient currents propagating along the substation busbars. At the moment of switching, the busbars temporarily acts as antennae radiating transient electromagnetic fields within the substations. The radiated fields may interfere and disrupt normal operations of electronic equipment used within the substation for measurement, control and communication purposes. Hence there is the need to fully characterise the substation electromagnetic environment as early as the design stage of substation planning and operation to ensure safe operations of the electronic equipment. This paper deals with the computation of transient electromagnetic fields due to switching within a high voltage air-insulated substation (AIS) using the finite difference time domain (FDTD) metho

Testing of Materials and Elements in Civil Engineering

This book was proposed and organized as a means to present recent developments in the field of testing of materials and elements in civil engineering. For this reason, the articles highlighted in this editorial relate to different aspects of testing of different materials and elements in civil engineering, from building materials to building structures. The current trend in the development of testing of materials and elements in civil engineering is mainly concerned with the detection of flaws and defects in concrete elements and structures, and acoustic methods predominate in this field. As in medicine, the trend is towards designing test equipment that allows one to obtain a picture of the inside of the tested element and materials. Interesting results with significance for building practices were obtained