Browsing by Author "Sydor, Piotr"
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Item Open Access An aerospace requirements setting model to improve system design(Elsevier, 2014-10-31) Tomas Centrich, X.; Shehab, Essam; Sydor, Piotr; Mackley, Tim; John, Philip; Harrison, A.Decisions at an early conceptual stage of the product lifecycle, are made with relatively low confidence, but such decisions greatly influence the overall product and service development. It is, therefore, critical to define the risks involved in order to help designers to make informed decisions. This research project investigates the risk and uncertainties in delivering products to meet top-level business requirements. The aim is to improve the existing process of setting business requirements and the current design approaches to achieve an optimised system design. This project also examines different approaches in assessing the risk of product and service delivery. To achieve that, a dedicated software tool, based on Weibull distribution function reliability model, has been created. An example of Rolls-Royce Civil Large Engine (CLE) gas turbine design process is used in this research as the case study. An analysis of the gap between the current design achievements and the targeted business requirements of a new product is performed at whole engine, module and component level. Further comparison of the new product business requirements, the novelty in the design and the historical reliability data is used to define and assess the risk of new product delivery.Item Open Access Enhancing service requirements of technical product-service systems(Elsevier, 2015-10-09) Estebanez, L. Ruiz; Shehab, Essam; Sydor, Piotr; Mackley, Tim; John, Philip; Harrison, A.Due to the integration of product and services as a new business model, product reliability and strategies for cost reduction at the early design stage have become important factors for many manufacturing firms. It is, therefore, critical at this phase to analyse the risk involved with Service Requirements noncompliance in order to help designers make informed decisions; as these decisions have a large impact on the Product Life Cycle (PLC). An investigation has been performed into how Service Requirements are analysed in a service orientated business to achieve reduced Life Cycle Cost (LCC) and improvements of existing Service Requirements. Weibull distribution and Monte Carlo principle have been proposed to do so; as they are considered as the most widely used in product reliability studies in the industry sector. A generic methodology for risk evaluation of failure to deliver a new product against Service Requirements is presented in this paper. This is part of the ongoing research project which aims to, apart from comparing current and targeted Service Requirements, it also facilitates an optimisation of them at the minimum risk of nonconformity.Item Open Access Feed-forward observer-based intermittent fault detection(Elsevier, 2017-09-17) Sedighi, Tabassom; Foote, P. D.; Sydor, PiotrThis paper provided an approach to design feed-forward observer for nonlinear systems with Lipchitz nonlinearity and bounded unknown inputs (disturbances/uncertainties) to ensure the sensitivity against intermittent faults. The proposed observer design guarantees the system error stability. Some variables and scalars are also introduced to design observer's parameters, which bring more degrees of flexibility available to the designer. The designed observer is used to propose a precision fault detection scheme including adaptive threshold design to detect intermittent faults. The efficiency of the considered approach is examined by the intermittent failure case in the suspension system of a vehicle. Simulation results show that the accurate state estimation and fault detection are achieved successfully.Item Open Access An integrated aerospace requirement setting and risk analysis tool for life cycle cost reduction and system design improvement(Elsevier, 2015-10-27) Estébanez, L. Ruiz; Shehab, Essam; Sydor, Piotr; Mackley, Tim; John, Philip; Harrison, A.In the early conceptual stage of the service orientated model, decisions regarding the design of a new technical product are largely influenced by Service Requirements. Those decisions, therefore, have to merge both technical and business aspects to obtain desired product reliability and reduced Whole Life Cost (WLC). It is, therefore, critical at that phase to define the risk of potential noncompliance of Service Requirements in order to ensure the right design choices; as these decisions have a large impact on the overall product and service development. This paper presents outcome of research project to investigate different approaches used by companies to analyse Service Requirements to achieve reduced Life Cycle Cost (LCC). Analysis using Weibull distribution and Monte Carlo principle have been proposed here; based on the conducted literature review these are considered as the most widely used techniques in product reliability studies. Based on those techniques, a methodology and its software tool for risk evaluation of failure to deliver a new product against Service Requirements are presented in this paper. This is part of the on-going research project which, apart from analysing the gap between the current Service Requirements achievements and the design targets for a new aircraft engine, it also facilitates an optimisation of those requirements at the minimum risk of nonconformity.Item Open Access Optimal on-board / off-board partitioning of integrated vehicle health management system.(2014-04) Sydor, Piotr; Tsourdos, AntoniosThe research presented in this thesis is intended to investigate and develop method to address optimal on-board / off-board partitioning of Integrated Health Management (IVHM) System. The problem of optimal on-board / off-board partitioning of IVHM System, with the main focus on, but not limited to, diagnostics and prognostics, has not yet been examined in the current literature. As a result, there exist no current solutions to tackle the on-board / off-board partitioning problem. The main objective of this work is to propose, investigate and develop a novel method for optimal on-board / off-board partitioning of an aircraft IVHM System. The current (legacy) and future design aircraft system architectures have been critically reviewed, including analysis of technological limitations and barriers to implementation and integration of a partitioned IVHM System. Based on the findings from the literature review a set of main drivers for IVHM System partitioning has been defined in relation to health monitoring of aircraft system. These main drivers constitute the basis for the framework of further investigation towards optimal partitioning presented in this work. The novel criterion for optimal IVHM System partitioning has been investigated and developed in this work. The proposed criterion uses cost trade-off analysis with weighting coefficients related to a vehicle concept of operations (CONOPS). The criterion has been used to create the novel method for optimal on-board / off-board partitioning of IVHM System. New metrics to evaluate cost effectiveness of the partitioned IVHM System have been also developed. The computer program implementation and simulation study using synthetic data-set to test the proposed method is given here. The proposed novel method contributes to the evolvement of the emerging field of IVHM System.