Papers by Geeta Ramsoobag
2018 Annual Reliability and Maintainability Symposium (RAMS), 2018
This paper presents the research work investigating the applicability of and possible improvement... more This paper presents the research work investigating the applicability of and possible improvements to the Empirical Mode Decomposition (EMD) signal processing technique for simultaneously monitoring multi-component systems. A modified EMD algorithm was developed in MATLAB R2013b software with the input being time signal data from each data collection point for all components. To test and validate the approach a fault simulator test rig was used to gather data. Fault classification accuracy is evaluated using an Artificial Neural Network (ANN) classifier model. A final classification accuracy of 87.5% was obtained without fault localization for each component and 62.5% obtained with four classes of fault localization.
Centrifugal Pumps (CPs) are one of the most widely used industrial assets globally. Condition-bas... more Centrifugal Pumps (CPs) are one of the most widely used industrial assets globally. Condition-based maintenance (CBM) is one of the maintenance strategies applied for monitoring the operational conditions of CPs. Use of CBM has resulted in improvements in CP performance. However, CBM practice for maintenance planning is suboptimal. This work presents a case study which utilises a CBM approach for monitoring CPs as part of a safety critical Fire Water System aboard an Offshore Production Platform. A CBM approach for CP maintenance was researched, and the best practice identified. This was compared to the practices of the offshore company, and the deficiencies in application and data collection observed. A test programme was simulated which would represent the company’s operations. Subsequently, data was collected to assess the ability of CBM to identify various failures for CPs. Vibration data for the CPs was utilised to develop the P-F curve for pump failure as a result of faulty be...
Most practically collected datasets are plagued with issues of incompleteness and inaccuracies wh... more Most practically collected datasets are plagued with issues of incompleteness and inaccuracies which will cause erroneous reliability modeling and poor maintenance decisions. This work outlines an investigation into the use of Heuristic techniques to estimate the parameters of a stochastic life distribution by using failure data with Truncation and Censoring. A Maximum Likelihood Estimation (MLE) approach was utilized in which the Log-Likelihood function is modified to account for the Truncation and Censoring factors. A Differential Evolution (DE) algorithm developed in MATLAB R2013a minimizes the Negative Log Likelihood (NLL) function and obtains optimum parameters for the 2 Parameters (2-P) Weibull distribution. Results obtained from a series of designed experimental tests generalized the relationship between the increasing levels of Truncation and Censoring individually on the β and η parameters. The impact of the modified NLL technique was examined under cases of Left Truncated ...
Lecture Notes in Mechanical Engineering, 2016
The expediency of production in the Offshore Oil and Gas Industry is dependent upon high asset in... more The expediency of production in the Offshore Oil and Gas Industry is dependent upon high asset integrity levels as a result of well organised maintenance practices. There arises a need for a structured approach to maintenance optimisation for such a complex system. This paper outlines a process for designing an approach for maintenance optimisation of an Offshore Oil and Gas Production System. A detailed literature research on maintenance optimisation is performed to highlight the key tools, techniques and strategies applicable to this industry. In addition, further research was conducted on past optimisation frameworks in the area. The findings highlighted several key stages which were used to design the proposed framework however some stages were modified to accommodate specific elements relating to the industry of interest. This would serve to guide users on achieving effective optimisation for a range of assets. Although the initial stages have been tested future work will attempt to validate the complete framework with a practical case and perhaps extend it to include multi-criteria optimisation techniques.
Reliability Engineering & System Safety, 2019
Review of multi-criteria maintenance optimization work over a 27-year period. Classification ... more Review of multi-criteria maintenance optimization work over a 27-year period. Classification of multi-criteria optimization techniques. Study of Criteria, Alternatives and Constraints for maintenance optimization. Suitability assessment of multi-criteria techniques for maintenance applications. Recent developments of traditional techniques for Multi-Criteria Optimization.
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Papers by Geeta Ramsoobag