Search results for "Degradation model"
showing 3 items of 3 documents
Stochastic modeling and prediction of catalytic converters degradation
2009
This paper proposes a stochastic model for describing the degradation process of catalytic converters over time, where the degradation is indirectly measured through the emission of complex hydrocarbons (HC) in legislated driving cycles. The proposed model is the superposition of two processes, the former being a dependent increments process which describes the actual degradation process, and the latter a white noise process which models the experimental errors. In particular, the proposed model assumes that the degradation growth in a small usage interval depends on the degradation level at the beginning of the interval, rather than on the age of the converter. The model has been applied t…
Statistics-driven Development of OBD Systems: An Overview
2006
Automotive on-board diagnostic (OBD) systems are designed to keep critical components under control during vehicle functioning, and to alert the driver in case of severe malfunctions. OBD systems aimed at reducing polluting emissions are mandatory on new motor vehicles. Some research projects conducted in cooperation between universities and the automotive industry have been quite successful in terms of knowledge advancement and industrial gain. An updated overview of the adopted methodologies and results obtained are given in this article. Such results can be valuable for both theorists and practitioners, since they witness the use of statistics as a powerful catalyst of technical progress…
Novel performance-based technique for predicting maintenance strategy of bitumen stabilised ballast
2018
Abstract Despite being the most used worldwide, railway ballasted tracks presents high maintenance cost related to ballast settlement and particle degradation. With the aim of reducing life cycle costs, bitumen stabilised ballast (BSB) has been recently proposed as a relatively cheap alternative maintenance solution to be applied to existing tracks. This study aims at assessing the potential advantages of this technology, defining a novel maintenance strategy of traditional ballasted track-beds. A protocol for the application of the BSB technology and its associated maintenance strategy is defined. To estimate minor and major maintenance operations of BSB scenario in comparison to tradition…