Browsing by Author "Sreenuch, Tarapong"
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Item Open Access Condition based maintenance optimization of an aircraft assembly process considering multiple objectives(Hindawi Publishing Corporation, 2014-02-11) Li, Jin; Sreenuch, Tarapong; Tsourdos, AntoniosThe Commercial Aircraft Cooperation of China (COMAC) ARJ21 fuselage's final assembly process is used as a case study. Thefocus of this paper is on the condition based maintenance regime for the (semi-) automatic assembly machines and how theyimpact the throughput of the fuselage assembly process. The fuselage assembly process is modeled and analyzed by using agentbased simulation in this paper.The agent approach allows complex process interactions of assembly, equipment, and maintenanceto be captured and empirically studied. In this paper, the built network ismodeled as the sequence of activities in each stage, whichare parameterized by activity lead time and equipment used. A scatter search is used to find multiobjective optimal solutions forthe CBM regime, where the maintenance related cost and production rate are the optimization objectives. In this paper, in orderto ease computation intensity caused by running multiple simulations during the optimization and to simplify a multiobjectiveformulation,multipleMin-Max weightings are used to trace Pareto front. The empirical analysis reviews the trade-offs between theproduction rate and maintenance cost and how sensitive the design solution is to the uncertainties.Item Open Access Distributed embedded condition monitoring management systems based on OSA-CBM standard(Elsevier Science B.V., Amsterdam., 2013-02-28T00:00:00Z) Sreenuch, Tarapong; Tsourdos, Antonios; Jennions, Ian K.This paper presents an approach to distributed condition monitoring systems that offers a reusable software architecture for a class of condition monitoring (CM) applications. The focus of this paper deals with an open software framework for development of CM applications stemming from 1) the Open System Architecture for Condition Based Maintenance (OSA-CBM) specification, which is an architecture promoting interoperability, and 2) a component framework that enables reuse, data process partitioning, configuration and rapid deployment. The publish/subscribe mechanism is the primary model used for both intra- and inter-module communications. The framework is developed using Java and Remote Method Invocation (RMI) distributed middleware, and its application is demonstrated through a gearbox CM system, where the CM software are deployed on the distributed embedded devices. This approach provides software enabled capability to distribute/re-configure the CM data process (through the OSA-CBM common interface and data model) across the hardware platforms to meet the given system configuration.Item Open Access Prognostics for electronics components of avionics - NASA IGBT accelerated ageing case study(Cranfield University, 2013-12) Xie, Yuan'an; Sreenuch, Tarapong; Tsourdos, AntoniosInsulate gate bipolar transistors (IGBTs) are widely used in electric vehicles, railway locomotive and new generation aircrafts, due to the IGBTs have advantages in small conduction resistance and small drive current. Hence, the reliability of IGBTs directly affect the reliability and performance of these vehicle systems. In recent years, a series of research works about IGBT reliability, failure mode and ageing analysis have been carried out widely, and a suitable prognostics method for IGBT and an efficient algorithm for predicting the IGBT Remaining Useful Life (RUL) become increasingly important. In recent years, despite the research works on IGBT reliability, failure mode and effect analysis are carried out widely, the prognostics and prediction of the IGBT remaining useful life are still the bottleneck in the research work to develop IGBT health management system. In this thesis, a framework and algorithm of IGBT prognostics and RUL prediction were developed. The research was based on the IGBT accelerated ageing experiments. The IGBT ageing data were processed and analysed, and the mechanism of the IGBT degeneration was studied. Additionally, the IGBT degradation models were built to simulate the IGBT degeneration process which were utilised to develop the prognostics algorithm for predicting the IGBT RUL. Gamma distribution model, Exponential distribution model, Poisson distribution model and the combining distribution model were established, and Monte Carlo simulation was utilised in the algorithm to compute the IGBT remaining useful life. The collector emitter voltage (VCE) was used as precursor parameter in prognosis to predict the RUL. Seven IGBTs were experimented in this prognostics research. The RUL prediction results were analysed and compared, and the prognostics algorithm was developed and summarised. The accuracy of the RUL prediction was presented, and the root mean square error was utilised to analyse and compare the efficiency and applicability of different models. The study of the IGBT prognostics and algorithm development were summarised and demonstrated.Item Open Access Simulation and Optimization of Integrated Maintenance Strategies for an Aircraft Assembly Process(Cranfield University, 2013-11) Li, Jin; Sreenuch, Tarapong; Tsourdos, AntoniosIn this thesis, the COMAC ARJ21 fuselage’s final assembly process is used as a case study. High production rate (i.e. number of aircraft assembled per year) with reasonable cost is the overall aim in this example. The output of final assembly will essentially affect the prior and subsequent processes of the overall ARJ21 production. From the collected field data, it was identified that a number of disruptions (or bottlenecks) in the assembly sequence were caused by breakdowns and maintenance of the (semi-)automatic assembly machines like portable computer numerical control (CNC) drilling machine, rivet gun and overhead crane. The focus of this thesis is therefore on the maintenance strategies (i.e. Condition-Based Maintenance (CBM)) for these equipment and how they impact the throughput of the fuselage assembly process. The fuselage assembly process is modelled and analysed by using agent-based simulation in this thesis. The agent approach allows complex process interactions of assembly, equipment and maintenance to be captured and empirically studied. In this thesis, the built network is modelled as the sequence of activities in each stage. Each stage is broken down into critical activities which are parameterized by activity lead-time and equipment used. CBM based models of uncertain degradation and imperfect maintenance are used in the simulation study. A scatter search is used to find multi-objective optimal solutions for the CBM regime, where the maintenance-related cost and production rate are the optimization objectives. In this thesis, in order to ease computation intensity caused by running multiple simulations during the optimization and to simplify a multi-objective formulation, multiple Min-Max weightings are applied to trace Pareto front. The empirical analysis reviews the trade-offs between the production rate and maintenance cost and how these objectives are influenced by the design parameters.Item Open Access Software framework for prototyping embedded integrated vehicle health management applications(2014-02-28T00:00:00Z) Sreenuch, Tarapong; Tsourdos, Antonios; Jennions, Ian K.Integrated vehicle health management is a major component in a new, future fleet-management paradigm where a conscious effort is made to shift aircraft maintenance from a schedule-based approach to a more proactive and predictive approach (that is, condition-based maintenance). Its goal is to maximize fleet operational availability while minimizing the logistics footprint through monitoring of the deterioration of equipment conditions. A comprehensive integrated vehicle health-management system will be executed in an environment that includes different sensor technologies, multiple information systems, and different data models. Integrated vehicle healthmanagement implementers have to therefore deal with an integration problem that involves different specialized algorithms and embedded hardware platforms. Integrated vehicle health management applications will have common execution logic, and many will share the same data-processing algorithms; hence, development productivity and the quality of integrated vehicle health management applications can be increased through reusable software building blocks and algorithm libraries or, in particular, by using a software development framework. This paper presents an approach to distributed integrated vehicle health management systems that offers reusable software architecture for a class of integrated vehicle health management applications. The focus of this paper deals with an open software framework for development of integrated vehicle health management applications stemming from the open system architecture for a condition-based maintenance specification, which is an architecture-promoting interoperability and a component framework that enables reuse, data-process partitioning, configuration, and rapid prototyping. The framework is developed using Java and Internet communications engines' distributed middleware, and its application is demonstrated through a gearbox health-monitoring system, where the integrated vehicle health management software is deployed on the distributed embedded devices. This approach provides software-enabled capability to distribute/reconfigure the integrated vehicle health management data process (through the open system architecture for condition-based maintenance common interface and data model) across the hardware platforms to meet the given system configuration. The performance evaluation for the test example shows negligible overhead in the central processing unit, band width, and latency when using the framework.Item Open Access Vehicle level health assessment through integrated operational scalable prognostic reasoners(Cranfield University, 2015-11) Khan, Faisal; Tsourdos, Antonios; Sreenuch, TarapongToday’s aircraft are very complex in design and need constant monitoring of the systems to establish the overall health status. Integrated Vehicle Health Management (IVHM) is a major component in a new future asset management paradigm where a conscious effort is made to shift asset maintenance from a scheduled based approach to a more proactive and predictive approach. Its goal is to maximize asset operational availability while minimising downtime and the logistics footprint through monitoring deterioration of component conditions. IVHM involves data processing which comprehensively consists of capturing data related to assets, monitoring parameters, assessing current or future health conditions through prognostics and diagnostics engine and providing recommended maintenance actions. The data driven prognostics methods usually use a large amount of data to learn the degradation pattern (nominal model) and predict the future health. Usually the data which is run-to-failure used are accelerated data produced in lab environments, which is hardly the case in real life. Therefore, the nominal model is far from the present condition of the vehicle, hence the predictions will not be very accurate. The prediction model will try to follow the nominal models which mean more errors in the prediction, this is a major drawback of the data driven techniques. This research primarily presents the two novel techniques of adaptive data driven prognostics to capture the vehicle operational scalability degradation. Secondary the degradation information has been used as a Health index and in the Vehicle Level Reasoning System (VLRS). Novel VLRS are also presented in this research study. The research described here proposes a condition adaptive prognostics reasoning along with VLRS.