Browsing by Author "Edwards, Rodger"

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    Amplitude of probability density function (APDF) of vibration response as a robust tool for gearbox diagnosis
    (Blackwell Publishing Ltd, 2012-12-31T00:00:00Z) Rzeszucinski, P. J.; Sinha, J. K.; Edwards, Rodger; Starr, Andrew G.; Allen, B.
    A ‘Go' or ‘No Go' assessment is a safety requirement for quick and robust estimation of the condition of gearboxes used in helicopters and other critical machines. A range of vibration-based condition indicators (CIs) has been developed to meet this requirement. CIs are compared automatically with pre-set threshold values representing a healthy system, so that the health of the gearbox can be assessed and diagnosis made where necessary. The use of kurtosis of the residual signal of the measured vibration data, computed as part of the ‘FM4' method, is widespread, because it is accepted as a good and reliable indicator. However, it has been observed in some cases that FM4 may not show a continually increasing trend with the propagation of a fault. This behaviour may lead to improper assessment of the severity of the fault. Hence, a new CI, based on the deviation in the normal probability density function (PDF) of the measured vibration data, is suggested which demonstrates an increasing trend that is more robustly and monotonically correlated with the fault propagation.
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    The EUCAMS gear partnership - a model of industry/academic collaboration
    (British Institute of Non-Destructive Testing, 2011-12-31) Starr, Andrew; Khan, Muhammad; Allen, Brian; Marshall, Mick; Phang, Albert; Badi, Nuri; Chen, Yong Kang; Edwards, Rodger; Sinha, Jyoti; Rzeszucinski, Pawel; Jones, Rhys; Mao, Ken; Shepherd, Duncan; Curran, Alan
    Challenges in maintenance systems can pose multi-faceted problems, which are difficult to resolve alone. Over a four year period, a partnership evolved a vision for tackling the understanding of fundamentally difficult mechanical failures and their detection, with potential for practical exploitation of the solutions. The partnership assembled a team of researchers and far-sighted project management, to undertake a study of gearbox failures, including finite element modelling, gear testing, and signal analysis. The partnership trained a series of doctoral and postdoctoral staff in running an integrated project, coping with changes in staffing and locations. The final stages of the work will validate the models and signal processing.
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    Methodology and theory evaluation of overall equipment effectiveness based on market
    (Emerald Group Publishing Limited, 2010-12-31T00:00:00Z) Anvari, Farhad; Edwards, Rodger; Starr, Andrew G.
    Purpose - Continuous manufacturing systems used within the steel industry involve different machines and processes that are arranged in a sequence of operations in order to manufacture the products. The steel industry is generally a capital-intensive industry and, because of high capital investment, the utilisation of equipment as effectively as possible is of high priority. This paper seeks to illustrate a new method, overall equipment effectiveness market-based (OEE-MB) for the precise calculation of equipment effectiveness for full process cycle in order to respond to the steel market. Design/methodology/approach - A refinement of the existing concept of OEE is developed based on a new scheme for loss analysis within market time. The paper illustrates the concept with a case study based on compact strip manufacturing processes within the steel industry. Findings - While the results for OEE by ignoring a considerable amount of possible hidden losses might be satisfying, the OEE-MB report shows potential room for improvement. It reflects changes in both the internal and external market for the steel industry, and therefore provides a tool not only for monitoring but also for managing improvement. Practical implications - OEE-MB is an applicable method for the precise calculation of equipment effectiveness that provides a sound perspective on improvement of steel plants by taking into consideration all losses within market time for meeting both internal and external demands. Originality/value - OEE-MB monitors production and measures the equipment effectiveness for full process cycle in order to meet the market. It makes communication more efficient and easier within the steel industry and may be used as a benchmark to achieve world-class standard.
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    Normalised Root Mean Square and Amplitude of Sidebands of Vibration Response as Tools for Gearbox Diagnosis
    (Blackwell Publishing Ltd, 2012-12-31T00:00:00Z) Rzeszucinski, P. J.; Sinha, J. K.; Edwards, Rodger; Starr, Andrew G.; Allen, B.
    Quick assessment of the condition of gearboxes used in helicopters is a safety requirement. One of the most widely used helicopter on-board-mounted condition monitoring system these days is the Health and Usage Monitoring System. It has been specifically designed to monitor the condition of all safety-critical components operating in the helicopter through calculation of so-called condition indicators (CIs) - signal processing routines designed to output a single number that represents the condition of the monitored component. Among number of available parameters, there is a couple of CIs that over the years of testing have earned a reputation of being the most reliable measures of the gear tooth condition. At the same time, however, it has been observed that in some cases, those techniques do not properly indicate the deteriorating condition with the propagation of a gear tooth fault with the period of operation. Hence, three more robust methods have been suggested, which are discussed in this article.