Off-line condition monitoring of powered train doors.

Powered passenger train door unreliability is a major source of in-service delay and cancellation to passenger train services. This unreliability costs UK Train Operating Companies significant amounts of money through Railtrack charges, customer compensation payments and loss of revenue as well as door maintenance and repair procedures. The successful and reliable identification of incipient powered door faults could therefore help to reduce these charges and subsequent maintenance costs, increase train reliability and potentially reduce safety-related incidents.This thesis presents the research and development of an off-line condition monitoring tool for electric powered passenger train doors, the Door Analysis Tool. The Door Analysis Tool was developed through a two-year, collaborative TCS project between Sheffield Hallam University and Interfleet Technology, an international railway engineering consultancy. The project was partly funded by the Department of Trade and Industry.This thesis focuses on a number of primary areas of work, namely: Introduction to powered train doors and condition monitoring in the railway industry; Identification of suitable data collection and condition monitoring equipment forpowered train doors; Development of suitable data analysis and interpretation algorithms; Development of a commercially viable prototype condition monitoring product forpowered passenger train doors, the Door Analysis Tool; Validation of the Door Analysis Tool through theoretical and practical testing; Identification of further development opportunities and further future work.The Door Analysis Tool uses clamp-on current probes to measure the door motor current characteristic and traction interlock status during opening and closing cycles to monitor the performance of train doors. It offers a range of opportunities to different parties within the railway industry to help reduce the impact of powered train door unreliability and thereby improve train performance through the identification of faulty train doors prior to costly in-service failures.The practical testing of the prototype Door Analysis Tool showed that it functions as intended in a train maintenance depot environment and that it is capable of collecting, analysing and classifying data relating to train door performance.The theoretical tests presented the prototype Door Analysis Tool with nine different sets of data, each representing a range of faulty and fault-free door operations. The Door Analysis Tool was able to correctly classify six of the nine tests. Three of the tests incorporating minor fault conditions were not highlighted by the door performance classification, however all of the theoretical faults were identifiable through inspection of the analysis parameters, which can be stored after each test. The sensitivity of the Door Analysis Tool analysis routines can be adjusted to tailor the tool to different systems

Power Quality in Electrified Transportation Systems

"Power Quality in Electrified Transportation Systems" has covered interesting horizontal topics over diversified transportation technologies, ranging from railways to electric vehicles and ships. Although the attention is chiefly focused on typical railway issues such as harmonics, resonances and reactive power flow compensation, the integration of electric vehicles plays a significant role. The book is completed by some additional significant contributions, focusing on the interpretation of Power Quality phenomena propagation in railways using the fundamentals of electromagnetic theory and on electric ships in the light of the latest standardization efforts

The application of time-frequency methods of acoustic signal processing in the diagnostics of tram drive components

The paper presents the course of investigations and the analysis of the possibility of applying selected methods of time-frequency processing of non-stationary acoustic signals in the assessment of the technical condition of tram drive  components, as well as a new combined method proposed by the authors. An experiment was performed in the form of a pass-by test of the acoustic pressure generated by a Solaris Tramino S105p tram. A comparative analysis has been carried out for an efficient case and a case with damage to the traction gear of the third bogie in the form of broken gear teeth. The recorded signal was analyzed using short-time Fourier transform (STFT) and continuous wavelet transform (CWT). It was found that the gear failure causes an increase in the sound level generated by a given bogie for frequencies within the range of characteristic frequencies of the tested device. Due to the limitations associated with the fixed window resolution in STFT and the inability to directly translate scales to frequencies in CWT, it was found that these methods can be helpful in determining suspected damage, but are too imprecise and prone to errors when the parameters of both transforms are poorly chosen. A new CWT-Cepstrum method was proposed as a solution, using the wavelet transform as a pre-filter before cepstrum signal processing. With a sampling rate of 8192 Hz, a db6 mother wavelet, and a scale range of 1:200, the new method was found to infer the occurrence of damage in an interpretation-free manner. The results were validated on an independent pair of trams of the same model with identical damage and as a reference on a pair of undamaged trams demonstrating that the method can be successfully replicated for different vehicles

Research and Technology

Johnson Space Center (JSC) accomplishments in new and advanced concepts during 1989 are highlighted. This year, reports are grouped in sections, Medical Science, Solar System Sciences, Space Transportation Technology, and Space Systems Technology. Summary sections describing the role of JSC in each program are followed by descriptions of significant tasks. Descriptions are suitable for external consumption, free of technical jargon, and illustrated to increase ease of comprehension

Industrial and Technological Applications of Power Electronics Systems

The Special Issue "Industrial and Technological Applications of Power Electronics Systems" focuses on: - new strategies of control for electric machines, including sensorless control and fault diagnosis; - existing and emerging industrial applications of GaN and SiC-based converters; - modern methods for electromagnetic compatibility. The book covers topics such as control systems, fault diagnosis, converters, inverters, and electromagnetic interference in power electronics systems. The Special Issue includes 19 scientific papers by industry experts and worldwide professors in the area of electrical engineering

Large space structures and systems in the space station era: A bibliography with indexes (supplement 04)

Bibliographies and abstracts are listed for 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system between 1 Jul. and 30 Dec. 1991. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems

Space station automation study: Autonomous systems and assembly, volume 2

This final report, prepared by Martin Marietta Denver Aerospace, provides the technical results of their input to the Space Station Automation Study, the purpose of which is to develop informed technical guidance in the use of autonomous systems to implement space station functions, many of which can be programmed in advance and are well suited for automated systems

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen