Hardware-in-the-loop performance analysis of a railway traction system under sensor faults

Fault mode and effects analysis (FMEA) has been used during decades for analysing the effects of faults in different applications. Initially, FMEA based on risk priority numbers provided information about the effects in the system, but during the last years different approaches have been developed to obtain a more robust risk evaluation. The proposed enhanced FMEA can provide the quantitative effects of sensor faults in a railway traction drive, in variables such as torque, current and voltages. In addition to the previous work, quantitative effects on overall performance indicators, such as energy efficiency and comfort, are obtained too. Hardware-in-the-loop (HIL)-based fault injection approach has been used to generate fault scenarios. The test platform is composed of a real-time simulator and a commercial traction control unit for a railway application

Design of measurement methodology for the evaluation of human exposure to vibration in residential environments

Exposure-response relationships are important tools for policy makers to assess the impact of an environmental stressor on the populace. Their validity lies partly in their statistical strength which is greatly influenced by the size of the sample from which the relationship is derived. As such, the derivation of meaningful exposure-response relationships requires estimates of vibration exposure at a large number of receiver locations. In the United Kingdom a socio-vibrational survey has been conducted with the aim of deriving exposure-response relationships for annoyance due to vibration from (a) railway traffic and (b) the construction of a new light rail system. Response to vibration was measured via a questionnaire conducted face-to-face with residents in their own homes and vibration exposure was estimated using data from a novel measurement methodology. In total, 1281 questionnaires were conducted: 931 for vibration from railway traffic and 350 for vibration from construction sources. Considering the interdisciplinary nature of this work along with the volume of experimental data required, a number of significant technical and logistical challenges needed to be overcome through the planning and implementation of the fieldwork. Four of these challenges are considered in this paper: the site identification for providing a robust sample of the residents affected, the strategies used for measuring both exposure and response and the coordination between the teams carrying out the social survey and the vibration measurements