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Dissertations / Theses on the topic 'Vehicle maintenance'
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Krishnamaraja, Magesh. "Extracting Maintenance Knowledge from Vehicle Databases." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-24586.
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Every vehicle or truck manufacturer maintains databases regarding the service information oftheir vehicles. In this thesis, two vehicle databases: Vehicle Specification Database andMaintenance Service Database are analyzed and compared. The purpose is to explore theconnection between vehicle specification and vehicle maintenance needs. The approach is touse different clustering algorithms(Hierarchical, K-means, Spectral), distance measures (PositiveMatching Index and a modified Positive Matching Index), cluster validity measures(Rand Index,Jaccard Index) and data representations(Binary, Frequency) on these databases to determinethe important maintenance related specification attributes and their relation to differentservice problems (e.g. engine, brake, clutch) The clustering results indicate that there is arelation between vehicle specification and vehicle maintenance profiles. Different data miningrules that connect vehicle specification with vehicle maintenance needs are derived from theclustering results.
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Gustafsson, Michael. "Running Dynamics for a Maintenance Railway Vehicle." Thesis, KTH, Järnvägsteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172213.
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BS Verkstäder has developed a new railway maintenance vehicle, MTR2000, which is in the process of authority approval. A part of the approval is the running dynamics of the vehicle which for maintenance vehicles following SS‐EN 14033‐1 can be evaluated using a simulation model of the vehicle, which is verified by comparing simulation results to measurements from a vehicle test. The testing, assessment values and limit values for running dynamics follow EN 14363. The goal of this work was to create a simulation model of the vehicle in the software Gensys and to verify the model with vehicle tests. Using the verified model, simulations were then performed corresponding to the test conditions defined in the standard for approval of running behaviour. The model was also used to investigate how the vehicle’s running behaviour could be improved. The results of the verification showed that the model gave a good representation of the vehicle up to the frame, while attempts to have similar good representation for the cabin were not successful. There were also other aspects of the verification process which could question the validity of the model. With the verification only being partly successful all further simulations were done with focus kept on results up to the frame were the verification had given the best results. The results of these latter simulations showed that the vehicle would most likely pass an authority approval process in its current configuration. Simulations performed to try to improve the vehicle running behaviour showed that a decrease of 50% in damper constant for the vehicle’s hydraulic dampers would lead to decreased acceleration levels and lower wheel‐rail guiding forces.BS Verkstäder har tagit fram ett nytt arbetsfordon, MTR2000, som är i en pågående process för myndighetsgodkännande. En del av detta godkännande avser fordonets gångdynamik vilken för arbetsfordon, som följer standard SS‐EN 14033‐1, kan utvärderas med en simuleringsmodell av fordonet, som är verifierad med en jämförelse av simuleringsresultat och mätningar från ett fordonstest. De tester, storheter och gränsvärden som sedan används följer standard EN 14363. Målet med detta arbete var att skapa en simuleringsmodell av fordonet i mjukvaran Gensys och sedan verifiera modellen med fordonstest. Med den verifierade modellen utfördes sedan simuleringar för de testförhållanden som standarden beskriver. Därefter användes modellen även till att undersöka om fordonets gångegenskaper kunde förbättras. Resultaten av verifieringen visade att modellen gav en god representation av fordonet upp till ramen, medan försök att få en lika bra representation upp till hytten inte var framgångsrika. Det fanns även andra aspekter av verifikationsprocessen som kan ifrågasätta modellens validitet. Då verifikationen endast var delvis framgångsrik, lades fokus på resultat upp till ramen i alla vidare simuleringar, då det var där verifikationen gav bäst resultat. Resultaten av dessa vidare simuleringar visade att fordonet med stor sannolikhet skulle klara av ett myndighetsgodkännande i sin nuvarande konfiguration. Simuleringar utförda med syfte att försöka förbättra fordonets gångegenskaper visade att en minskning på 50% av dämparkonstanten för fordonets hydrauliska dämpare skulle leda till minskade accelerationsnivåer samt lägre hjul‐räl krafter.
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Tyagi, Prakhar. "Chassis predictive maintenance and service solutions." Thesis, KTH, Fordonsdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-265587.
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Predictive Maintenance (PdM) accumulates data from multiple sensors developing a statistical model which identifies the key failures even before they take place. The main focus of this thesis work has been the proposal of a machine learning based system designed for predicting the failure of mechanical parts that require replacement. The main investigation explores the possibilities of implementing machine learning algorithm for predicting the parts that require replacement and which is found from the electronic errors that the vehicle exhibits. A strong association between the parts that cause faults and electronic error codes helps in yielding a powerful diagnostics tool. The study has considered three error components namely; broken damper, noisy wheel hub and the reference value for the validation purpose. The model vehicle used for the study is Volvo V90. To acquire variance in this study data, diverse tracks with different speeds were used. The machine learning algorithm that was developed can classify and detect mechanical failures using an Support Vector Machine (SVM) algorithm based on various statistical learning methods. The study carried out an fast Fourier transform (FFT) analysis in association with the data acquired from front left wheel. The main area of interest is the FFT domain of 5-20hz. The study outcome indicated that the used model is capable of predicting the hysteretic responses associated with the faulty components like broken damper and noisy wheel hub. The designed model can be used for analysing the system’s response and for designing and controlling the faulty components in the car. However, the results of this thesis work can be used to implement the time-based prediction of mechanical component decay.Prediktivt Underhåll (PdM) är en statistisk modell som samlar data från flera olika sensorer och som identifierar fel innan de äger rum. Huvudfokus för detta examensarbete har varit förslaget till ett maskininlärningsbaserat system som är utformat för att förutsäga fel i mekaniska delar som kräver utbyte. Examensarbetet undersöker möjligheterna att implementera en maskininlärningsalgoritm för att förutsäga de mekaniska delar som kräver utbyte och som framgår av de elektroniska fel som fordonet uppvisar. En stark koppling mellan de delar som orsakar fel och elektroniska felkoder hjälper till att ge ett kraftfullt diagnostiskt verktyg. Studien har beaktat tre felkomponenter nämligen; trasig dämpare, missljud från hjulnav och referensvärdet för valideringsändamål. Modellfordonet som används för studien är Volvo V90. För att få varians i informationen för detta arbete användes olika provbanor med olika vägförhållanden med olika hastigheter. Maskininlärningsalgoritmen som utvecklades kan klassificera och upptäcka mekaniska fel med hjälp av en SVM-algoritm (Support Vector Machine) baserad på olika statistiska inlärningsmetoder. Studien genomförde en snabb Fourier-transform (FFT) analys i samband med de data som förvärvades från det främre vänstra hjulet. Huvudintresseområdet är FFT-domänen 5-20 Hz. Studiens resultat visade att den använda modellen kan: Identifiera och klassificera data som är förknippade med de felaktiga komponenterna som trasig dämpare och missljud i hjulnav. Modellen kan användas för vidare prediktera och ge förslag när ett mekaniskt fel på dämpare eller hjulnav håller på att ske. Det här examensarbetet täcker inte tidsbunden prediktion utan snarare identifierar när nedbrytningen av mekaniska komponenter har skett. Resultaten från detta examensarbete kan emellertid användas för att implementera en tidsbaserad prediktion för mekaniska komponentfel.
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Mullins, Michael, Troy Adams, and Robert Simms. "Analysis of light armored vehicle depot level maintenance." Thesis, Monterey, California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/34227.
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MBA Professional ReportAn analysis of Light Armored Vehicle (LAV) Depot Level Maintenance is conducted to examine the scheduled maintenance cycle and processes in order to determine potential inefficiencies related to cost or time. Performance is measured by analyzing costs, cycle time, quality, availability, and flexibility. Current operations in Iraq are considered for effects on depot level maintenance, depot capacity, and operational availability. This analysis has implications in determining whether depot level maintenance should be conducted at Barstow, California, or Albany, Georgia, or at both facilities as it is now.
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Gutierrez, Bonilla Andres Felipe. "Maintenance Scheduling and Vehicle Routing Optimisation with Stochastic Components." Thesis, Troyes, 2018. http://www.theses.fr/2018TROY0023.
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Cette thèse est dédiée aux problèmes de tournées de véhicules stochastiques (SVRP) abordés dans un contexte de planification de tâches de maintenance. Le paradigme de solutions À Priori est choisi pour inclure les incertitudes au moment de la planification. Deux SVRP sont étudiés, d’abord le problème avec demandes stochastiques, qui est résolu par un algorithme mémétique (MA) hybridé avec une procédure de recherche adaptative randomisée. La méthode s’est montrée compétitive en comparaison à d’autres approches disponibles dans la littérature. Ensuite le SVRP avec fenêtre de temps sur le service, et temps de trajets et de services stochastiques est considéré. Un algorithme mémétique parallèle est conçu pour le résoudre efficacement. Un troisième problème traitant de l’ordonnancement de la maintenance pour un parc d’éoliennes est étudié dans cette thèse. D’abord une version déterministe et bi-objective est modélisée sous forme d’un programme linéaire à variables mixtes, puis résolue par une méthode de type epsilon contraintes. Une extension du problème sur un horizon de planification long et considérant les stratégies de maintenance est également proposée, et le problème est résolu par une méthode basée sur la simulation. Les méthodes développées mettent en évidence, pour les deux derniers problèmes, le conflit entre la minimisation des coûts de maintenance et la maximisation de la production énergétiqueThis thesis studies Stochastic Vehicle Routing Problems (SVRPs) in the context of maintenance tasks scheduling. Stochastic programming under an A Priori paradigm is used to incorporate the uncertainties. Two SVRPs are addressed, the first one deals with Stochastic Demands which is solved by a hybrid approach combining a memetic algorithm (MA) and a Greedy Randomized Adaptive Search Procedure (GRASP). The designed hybrid method is shown to be competitive compared to other published approaches. Second, the SVRP with stochastic travel and service times and hard time windows investigated. A parallel Memetic Algorithm is designed to solve efficiently this last problem. A third problem devoted to maintenance scheduling in wind farm context is also studied in this work. First the problem is formulated as a deterministic linear bicriteria mixed integer program, then an epsilon constraint is developed to solve it. An extension to a maintenance planning problem involving a long horizon is also addressed using a simulation approach. This last part also considers maintenance strategies selection. Both developed approaches show the existing conflicts between energy production maximization and maintenance costs minimization
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Samoylov, Alexander V. "Improvement of the efficiency of vehicle inspection and maintenance programs through incorporation of vehicle remote sensing data and vehicle characteristics." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50410.
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Emissions from light-duty passenger vehicles represent a significant portion of total criteria pollutant emissions in the United States. Since the 1970s, emissions testing of these vehicles has been required in many major metropolitan areas, including Atlanta, GA, that were designated to be in non-attainment for one or more of the National Ambient Air Quality Standards. While emissions inspections have successfully reduced emissions by identifying and repairing high emitting vehicles, they have been increasingly inefficient as emissions control systems have become more durable and fewer vehicles are in need of repair. Currently, only about 9% of Atlanta area vehicles fail emissions inspection, but every vehicle is inspected annually. This research addresses explores ways to create a more efficient emissions testing program while continuing to use existing testing infrastructure. To achieve this objective, on road vehicle emissions data were collected as a part of the Continuous Atlanta Fleet Evaluation program sponsored the Georgia Department of Natural Resources. These remote sensing data were combined with in-program vehicle inspection data from the Atlanta Vehicle Inspection and Maintenance (I/M) program to establish the degree to which on road vehicle remote sensing could be used to enhance program efficiency. Based on this analysis, a multi-parameter model was developed to predict the probability of a particular vehicle failing an emissions inspection. The parameters found to influence the probability of failure include: vehicle characteristics, ownership history, vehicle usage, previous emission test results, and remote sensing emissions readings. This model was the foundation for a proposed emissions testing program that would create variable timing for vehicle retesting with high and low failure probability vehicles being more and less frequently, respectively, than the current annual cycle. Implementation of this program is estimated to reduce fleet emissions of 17% for carbon monoxide, 11% for hydrocarbons, and 5% for nitrogen oxides in Atlanta. These reductions would be achieved very cost-effectively at an estimated marginal cost of $149, $7,576 and $2,436 per-ton-per-year for carbon monoxide, hydrocarbons, and nitrogen oxides emissions reductions respectfully.
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Chen, Yujie. "Optimisation for large-scale maintenance, scheduling and vehicle routing problems." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/16107/.
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Solving real-world combinatorial problems is involved in many industry fields to minimise operational cost or to maximise profit, or both. Along with continuous growth in computing power, many asset management decision-making processes that were originally solved by hand now tend to be based on big data analysis. Larger scale problem can be solved and more detailed operation instructions can be delivered. In this thesis, we investigate models and algorithms to solve large scale Geographically Distributed asset Maintenance Problems (GDMP). Our study of the problem was motivated by our business partner, Gaist solutions Ltd., to optimise scheduling of maintenance actions for a drainage system in an urban area. The models and solution methods proposed in the thesis can be applied to many similar issues arising in other industry fields. The thesis contains three parts. We firstly built a risk driven model considering vehicle routing problems and the asset degradation information. A hyperheuristic method embedded with customised low-level heuristics is employed to solve our real-world drainage maintenance problem in Blackpool. Computational results show that our hyperheuristic approach can, within reasonable CPU time, produce much higher quality solutions than the scheduling strategy currently implemented by Blackpool council. We then attempt to develop more efficient solution approaches to tackle our GDMP. We study various hyperheuristics and propose efficient local search strategies in part II. We present computational results on standard periodic vehicle routing problem instances and our GDMP instances. Based on manifold experimental evidences, we summarise the principles of designing heuristic based solution approaches to solve combinatorial problems. Last bu not least, we investigate a related decision making problem from highway maintenance, that is again of interest to Gaist solutions Ltd. We aim to make a strategical decision to choose a cost effective method of delivering the road inspection at a national scale. We build the analysis based on the Chinese Postman Problem and theoretically proof the modelling feasibility in real-world road inspection situations. We also propose a novel graph reduction process to allow effective computation over very large data sets.
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Flodin, Jesper. "Investigate the track gauge widening on the Iron-ore line and suggest maintenance limits." Thesis, KTH, Spårfordon, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280154.
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Iron ore export remains a major player in the Swedish economy to date, with 90% of all iron ore produced in Europe stemming from the relatively small northern country. A large amount of this ore is transported from the mines to harbours for world-wide freight on railways. On such railway is the SwedishIron-ore Line running from Kiruna to Riksgränsen, connecting to the Norwegian Ofoten line which continues to Narvik. The line has the highest permissible axle-load in Europe at 30 tonnes, which poses challenges in its own. Historically, damage on the high rail of curves have been problematic, butremedies introduced in the form of wear adapted rail profiles has brought light to a new issue. Lowrail spalling damage, caused by rolling contact fatigue (RCF) has been problematic on the line, as it reduces the life of the rails and increases maintenancecosts. It is believed that a major factor to this damage is the track gauge width. The current limit values for maintenance of the track gauge is set at 1450mm, a figure derived from empirical studies. It is therefore the wish of the infrastructure manager Trafikverket to investigate the effect the gaugewidth has on this RCF induced damage, in order to review current maintenance practices. By applying current state of the art in rail vehicle dynamics simulations and contact mechanics, the current maintenance limit has been investigated.The outcome of said investigation has yielded a foundation of support for the current maintenance limit, as it closely aligns with where damage is calculated to form at a significantly higher rate than at lower gauges.Malmexport utgör idag en av de största pelarna av Sveriges ekonomi och står ensamt för produktionen av 90% av all järnmalm som produceras i Europa. En stor del av denna malm transporteras från gruvorna till hamnar för vidare frakt på fartyg med hjälp utav järnvägar. En sådan järnväg är den Svenska Malmbanan som går mellan Kiruna och Riksgränsen, med direkt anslutning till norska Ofotenbanan som fortsätter till Narvik. Banan är den tyngsta i sitt slag i Europa med en största tillåten axellast på 30 ton, vilket innebär egna utmaningar. Rälskador på ytterrälen i kurvor har tidigare varit problematiska, men tidiga åtgärder i form av slitageanpassade rälprofiler har motverkat dessa, och istället skänkt uppmärksamhet åt ett annat problem. Ytsplittring på innerrälen i kurvor, orsakat av rullkontaktutmattning har varit problematiskt, då det reducerar rälens livslängd, och ökar underhållskostnaderna. En faktor som tros påverka dessa skador kraftigt är spårvidden. Den nuvarande spårviddsgränsen för banan är satt till 1450mm och är baserad på tidigare empiriska studier. Det är därför den svenska infrastrukturägaren, Trafikverkets, önskan att utreda effekten av spårvidden på rullkontaktutmattnings initierade skador. Genom att applicera den senaste kunskapen inom fordonsdynamiska simuleringar och kontaktmekanik, har den nuvarande underhållsgränsen utretts. Den nämnda utredning har resulterat i en grund som stöttar den nuvarande underhållsgränsen, då den nära överensstämmer med den plats där skadorna ökar mycket kraftigt i förhållande till smalare spårvidder.
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Dietz, Anthony, Eric Friets, William Finger, Jerry Bieszczad, Matt Miller, and Lawrence Freudinger. "ONLINE DISTRIBUTED VEHICLE AND MACHINERY HEALTH MANAGEMENT." International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/605375.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaModern aircraft and space vehicles routinely sense and record vast quantities of information relevant to assessing the vehicles’ health. However, limitations imposed by the bandwidth of telemetry and network connections prevent real-time transmission of the complete data set to central stations for analysis. An online health-management system suitable for bandwidth-limited network environments that enables interrogation of the full data set by ground-based operators is described. The system uses distributed objects organized in a data processing hierarchy linked by a buffered data-management subsystem. Reduced health information is routinely transmitted, but dynamic reports may be requested on demand from any object.
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Krutholm, Tommy. "En kvalitativ undersökning om infärgning ur matematiklärarens perspektiv. : Är infärgning den ultimata lösningen för ett G i matematik A för fordonselever?" Thesis, Karlstad University, Faculty of Arts and Education, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-2666.
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In this study the reader will learn how to work with student adaptation as a method for students to easier study and learn mathematics at a vocational school focusing on vehicle maintenance. This secondary school is located in the southern part of Sweden. Four math teachers who teach at this program use in-depth interview when it comes into explaining what they mean regarding adaptation and its role in teaching this students and helping them pass the course. This is very much a topic of today and has been so for some time. We hear about reports which reveals alarmingly low levels of know light which continue to drop especially at vocational programs in particular in mathematic. The math teachers describe specific obstacles and circumstances which in their experiences will limit their teaching options and alternatives and therefore will also limit the adaptation and its role. One may say in general that adaptation not necessarily is a method with an obvious template to follow so many various players will have to be involved in the teaching. This holds true with regards to all various aspects of learning. The student is here by enabled to see and experience the full picture of the program and the subject in question. No matter what the subject is, focus will always be the goal of the program and the students’ future careers. There are questions as to whether there may be conflicts of interest between the various actors involved in the learning process.
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Dees, Patrick Daniel. "A simulation framework for the analysis of reusable launch vehicle operations and maintenance." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45747.
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During development of a complex system, feasibility initially overshadows other concerns, in some cases leading to a design which may not be viable long-term. In particular for the case of Reusable Launch Vehicles, Operations&Maintenance comprises the majority of the vehicle's LCC, whose stochastic nature precludes direct analysis. Through the use of simulation, probabilistic methods can however provide estimates on the economic behavior of such a system as it evolves over time. Here the problem of operations optimization is examined through the use of discrete event simulation. The resulting tool built from the lessons learned in the literature review simulates a RLV or fleet of vehicles undergoing maintenance and the maintenance sites it/they visit as the campaign evolves over a period of time. The goal of this work is to develop a method for uncovering an optimal operations scheme by investigating the effect of maintenance technician skillset distributions on important metrics such as the achievable annual flight rate and maintenance man hours spent on each vehicle per flight. Using these metrics, the availability of technicians for each subsystem is optimized to levels which produce the greatest revenue from flights and minimum expenditure from maintenance.
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Foley, Adam T. "Data quality and reliability analysis of U.S. Marine Corps ground vehicle maintenance records." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45853.
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Approved for public release; distribution is unlimitedWe evaluate data quality issues present in Marine Corps maintenance records and develop statistical models to identify the most influential predictor variables to estimate the expected number of failures that cause a vehicle to be non-operational. When a vehicle becomes non-operational, we refer to it as a deadlining event. We analyze data collected from 3,154 Medium Tactical Vehicle Replacement (MTVR) vehicles between January 1, 2011 and December 31, 2013. Data quality issues are present in vehicle serial numbers, maintenance defect codes, regional code, and odometer readings. Due to the high level of inaccuracy in odometer meter readings, vehicle mileage cannot be used as a metric for usage. We build Poisson generalized linear regression models to estimate the expected number of vehicle deadlining events. Without the presence of a true measurement of vehicle usage, the insight gained from fitting regression models to the maintenance data is limited. The number of unscheduled maintenance events acts as a surrogate usage measure within the model. In our model, more than one scheduled maintenance event per year shows evidence of reducing the number of deadlining events. We recommend the improvement of odometer meter reading accuracy in order to provide an effective usage measurement for future studies.
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Whitlock, Wayne Ronald. "A critical analysis of service quality perceptions of vehicle repair and maintenance retailers." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1516.
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The South African motor industry plays a pivotal role in the economy of South Africa and is a leading indicator in economic change. In general, satisfaction of customer service in the motor industry is steadily improving. However, as research has shown, there is still room for improvement within the industry. Knowing what customers expect is a critical step in delivering good quality service to ensure customer retention in the long-term (Zeithaml, Parasuraman & Berry 1990:62-63). Having a good understanding of the value of forming long-term relationships with customers and their evaluation of the quality of the service provided, cannot be underestimated, as failure to actually ask customers what they think of the service could be detrimental in the long-term. Vehicle manufacturers conduct ongoing research to monitor customer perceptions of the quality of the service provided by their vehicle retailers. The information generated from the research findings can be used by manufacturers to improve levels of service where this appears to be lacking, and deal promptly with any customer complaints. Against this background, how vehicle owners judge the quality of the service provided by a franchised vehicle retailer for a repair and maintenance service, will be crucial to understanding how customers form perceptions of service related firms specifically, and in general, even an entire industry. The primary objective of this study is to assess customer perceptions of service quality with a franchised vehicle retailer following a routine repair and maintenance service. The sample consisted of 3 859 respondents who had their vehicles serviced at a GM South Africa franchised vehicle retailer over a one month period. The empirical results of the study revealed that GM South Africa show general positive results in terms of customer service satisfaction, however, there are some areas where additional attention is required.
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Rashid, Arin. "An exploratory study of winter road maintenance and the use of vehicle data." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-178678.
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The Swedish road network is maintained by the Swedish Transport Administration, municipalities, and entrepreneurs with the goal of keeping the roads in satisfactory condition for traffic. The road operators are responsible for different roads and have several legislations that regulate construction and operation. One important aspect of winter road maintenance is the monitoring of the road situation ahead in order to call out resources for preventive measures. This study is performed at the company NIRA Dynamics with the purpose of going towards more digitized winter road information. The study explores different winter maintenance organizations in Sweden, investigates the importance of the information needed to be able to detect when roads are deemed too risky, and tries to gain an understanding of how the vehicle data provided by NIRA Dynamics best can provide a service for the winter road maintainers. This study is based on eight semi-structured interviews, user-tests aswell as a literature study. The findings of the study show that different winter maintenance organizations can differ a lot depending on the size and governing policies of the municipalities or entrepreneurs. The main differences can be found in their requirements and their method of monitoring the road situation ahead. The findings also show that the vehicle data is promising and has the potential to optimize and improve the overall winter maintenance planning. However, implementing and understanding the vehicle data in a real-world context requires collaboration from the different organizations to fulfill its value.
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Wang, Qi, and Yinrong Ma. "Diagnostic tool for trucks : -from idea to demonstrator." Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-23551.
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Vehicles can end up in unplanned visits to workshops due to the driver not checking the vehicle status before using it in traffic. There are many factors not only caused by the environment but also due to the lack of tools that simplify or reminds about beforehand inspections. The purpose of this project was to introduce a smart-phone application that can display the health state (or related parameters) of a vehicle in a brief way and indicate if a part or function of the truck is not working properly. There are six functions in the application. Function status and function fault codes can display information about vehicles by giving two-dimensional plots about vehicle data, while function VSR displays some information in the form of text. Also, the user can submit their feedback through function comment. Function position is designed to give the users specific perspectives on an imported map based on their different user identity. Function check reminds about inspections that must be made before setting out on a driving mission. The application allows bus drivers and managers to continuously monitor different vehicle parameters with a statistical summary over time, as well as providing a method for following-up that drivers perform basic checks on the vehicle before it is taken into traffic.
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Wilson, Ronald S. "Cost-benefit analysis of single siting depot level maintenance for the Light Armored Vehicle." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA386343.
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Thesis (M.S. in Management) Naval Postgraduate School, Dec. 2000.Thesis advisor(s): Gue, Kevin R. ; Eaton, Donald. "December 200." Includes bibliographical references (p. 51-53). Also available in print.
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Prytz, Rune. "Machine learning methods for vehicle predictive maintenance using off-board and on-board data." Licentiate thesis, Högskolan i Halmstad, CAISR Centrum för tillämpade intelligenta system (IS-lab), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-27869.
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Vehicle uptime is getting increasingly important as the transport solutions become more complex and the transport industry seeks new ways of being competitive. Traditional Fleet Management Systems are gradually extended with new features to improve reliability, such as better maintenance planning. Typical diagnostic and predictive maintenance methods require extensive experimentation and modelling during development. This is unfeasible if the complete vehicle is addressed as it would require too much engineering resources. This thesis investigates unsupervised and supervised methods for predicting vehicle maintenance. The methods are data driven and use extensive amounts of data, either streamed, on-board data or historic and aggregated data from off-board databases. The methods rely on a telematics gateway that enables vehicles to communicate with a back-office system. Data representations, either aggregations or models, are sent wirelessly to an off-board system which analyses the data for deviations. These are later associated to the repair history and form a knowledge base that can be used to predict upcoming failures on other vehicles that show the same deviations. The thesis further investigates different ways of doing data representations and deviation detection. The first one presented, COSMO, is an unsupervised and self-organised approach demonstrated on a fleet of city buses. It automatically comes up with the most interesting on-board data representations and uses a consensus based approach to isolate the deviating vehicle. The second approach outlined is a super-vised classification based on earlier collected and aggregated vehicle statistics in which the repair history is used to label the usage statistics. A classifier is trained to learn patterns in the usage data that precede specific repairs and thus can be used to predict vehicle maintenance. This method is demonstrated for failures of the vehicle air compressor and based on AB Volvo’s database of vehicle usage statistics.
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Li, Ying. "Evaluating and Improving the Effectiveness of Vehicle Inspection and Maintenance Programs: A Cost-Benefit Analysis Framework." Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/2620.
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Motor vehicle inspection and maintenance (I/M) programs are designed to identify high-emitting vehicles and mitigate their impacts on air quality and climate. I/M programs have been traditionally ranked superior among various vehicle emission control measures by the results of cost-benefit analysis, based on the assumption that these programs will achieve the targeted emission reduction outcomes. However, the actual effects of I/M programs may be greatly uncertain and when this uncertainty is taken into account, these programs may become suboptimal. This study develops a new a cost-benefit analysis framework that links various program design consideration, such as program participation rate, identification rate and effective repair rate, to the public health benefits as well as costs of the programs. This framework helps decision makers to investigate minimum implementation requirements that at least ensure the benefits are greater than the costs of implementing the programs in order to improve the overall effectiveness of the I/M programs. To illustrate the applications of the framework, it was applied to a particulate matter oriented I/M program targeting all diesel-fueled vehicles in the city of Bangkok, Thailand, a large metropolitan area that has been suffering from severe ambient PM pollution mainly attributable to its wide use of diesel-fueled vehicles and motorcycles. It was found that the health benefits achieved from the program are sensitive to several key program design elements, including participation rate and problem vehicle identification rate, fraction of effective repairs and illegal operation rate. Other variables, such as the testing cut-points and vehicle population growth rate, only have modest effects on the overall emission reduction and consequent health benefits. Overall, the performance of multiple variables associated with I/M program design needs to be improved simultaneous in order to achieve the targeted benefits of the program.
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Berggren, Eric. "Railway Track Stiffness : Dynamic Measurements and Evaluation for Efficient Maintenance." Doctoral thesis, KTH, Farkost och flyg, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10360.
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Railway track stiffness (vertical track load divided by track deflection) is a basic parameter oftrack design which influences the bearing capacity, the dynamic behaviour of passing vehiclesand, in particular, track geometry quality and the life of track components. Track stiffness is abroad topic and in this thesis some aspects are treated comprehensively. In the introductionpart of the thesis, track stiffness and track stiffness measurements are put in their propercontext of track maintenance and condition assessment. The first aspect is measurement of track stiffness. During the course of this project, Banverkethas developed a new device for measurement of dynamic track stiffness called RSMV(Rolling Stiffness Measurement Vehicle). The RSMV is capable of exciting the trackdynamically through two oscillating masses above one wheelset. The dynamic stiffness is acomplex-valued quantity where magnitude is the direct relation between applied load anddeflection (kN/mm) and phase is a measure of deflection-delay by comparison with force. Thephase has partial relationship with damping properties and ground vibration. The RSMVrepeatability is convincing and both overall measurements at higher speeds (up to 50 km/h)and detailed investigations (below 10 km/h) can be performed. The measurement systemdevelopment is described in Paper A and B. The second aspect is evaluation of track stiffness measurements along the track from a trackengineering perspective. Actual values of stiffness as well as variations along the track areimportant, but cannot always answer maintenance and design related questions alone. InPaper D track stiffness is studied in combination with measurements of track geometryquality (longitudinal level) and ground penetrating radar (GPR). The different measurementsare complementary and a more reliable condition assessment is possible by the combinedanalysis. The relation between soft soils and dynamic track stiffness measurements is studiedin Paper C. Soft soils are easily found and quantified by stiffness measurements, in particularif the soft layer is in the upper part of the substructure. There are also possibilities to directlyrelate substructure properties to track stiffness measurements. Environmental vibrations areoften related to soft soils and partly covered in Paper C. One explanation of the excitationmechanism of train induced environmental vibrations is short waved irregular supportconditions. This is described in Paper E, where track stiffness was evinced to have normalvariations of 2 – 10 % between adjacent sleepers and variations up to 30 % were found. Anindicative way of finding irregular support conditions is by means of filtering longitudinallevel, which is also described in the paper. Train-track interaction simulation is used in PaperH to study track stiffness influence on track performance. Various parameters of trackperformance are considered, e.g. rail sectional moment, rail displacement, forces at wheel-railinterface and on sleepers, and vehicle accelerations. Determining optimal track stiffness froman engineering perspective is an important task as it impacts all listed parameters. The third aspect, efficient maintenance, is only partially covered. As track stiffness relates toother condition data when studied from a maintenance perspective, vertical geometricaldefects (longitudinal level and corrugation/roughness) are studied in paper F. The generalmagnitude dependency of wavelength is revealed and ways of handling this in conditionassessment are proposed. Also a methodology for automated analysis of a large set ofcondition data is proposed in Paper G. A case study where dynamic track stiffness,longitudinal level and ground penetrating radar are considered manifests the importance oftrack stiffness measurements, particularly for soil/embankment related issues.QC 20100623
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Revanur, Vandan, and Ayodeji Ayibiowu. "Automatic Generation of Descriptive Features for Predicting Vehicle Faults." Thesis, Högskolan i Halmstad, CAISR Centrum för tillämpade intelligenta system (IS-lab), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42885.
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Predictive Maintenance (PM) has been increasingly adopted in the Automotive industry, in the recent decades along with conventional approaches such as the Preventive Maintenance and Diagnostic/Corrective Maintenance, since it provides many advantages to estimate the failure before the actual occurrence proactively, and also being adaptive to the present status of the vehicle, in turn allowing flexible maintenance schedules for efficient repair or replacing of faulty components. PM necessitates the storage and analysis of large amounts of sensor data. This requirement can be a challenge in deploying this method on-board the vehicles due to the limited storage and computational power on the hardware of the vehicle. Hence, this thesis seeks to obtain low dimensional descriptive features from high dimensional data using Representation Learning. This low dimensional representation will be used for predicting vehicle faults, specifically Turbocharger related failures. Since the Logged Vehicle Data (LVD) was base on all the data utilized in this thesis, it allowed for the evaluation of large populations of trucks without requiring additional measuring devices and facilities. The gradual degradation methodology is considered for describing vehicle condition, which allows for modeling the malfunction/ failure as a continuous process rather than a discrete flip from healthy to an unhealthy state. This approach eliminates the challenge of data imbalance of healthy and unhealthy samples. Two important hypotheses are presented. Firstly, Parallel StackedClassical Autoencoders would produce better representations com-pared to individual Autoencoders. Secondly, employing Learned Em-beddings on Categorical Variables would improve the performance of the Dimensionality reduction. Based on these hypotheses, a model architecture is proposed and is developed on the LVD. The model is shown to achieve good performance, and in close standards to the previous state-of-the-art research. This thesis, finally, illustrates the potential to apply parallel stacked architectures with Learned Embeddings for the Categorical features, and a combination of feature selection and extraction for numerical features, to predict the Remaining Useful Life (RUL) of a vehicle, in the context of the Turbocharger. A performance improvement of 21.68% with respect to the Mean Absolute Error (MAE) loss with an 80.42% reduction in the size of data was observed.
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Goguen, Paul J., and Scott J. Purcell. "A cost analysis for life-cycle preventive maintenance, administrative storage, and condition-based maintenance for the U.S. Marine Corps medium tactical vehicle replacement." Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/38936.
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Approved for public release; distribution is unlimited.This study provides a cost-based analysis of preventive maintenance and administrative storage for the U.S. Marine Corps medium tactical vehicle replacement (MTVR). In the years 19952013, the Marine Corps acquired approximately 8,750 MTVRs as overseas obligations increased. As the current conflicts wind down and the Marine Corps returns to lower force levels, the Marine Corps will see excess capacity in its MTVR fleet. This study begins the process of finding a solution to managing this excess capacity. Based on net present value analysis for various combinations of continued preventive maintenance and storage of excess vehicles over their life cycle, this studys findings contribute to determining the most cost effective method of handling the Marine Corps MTVR fleet.
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Enblom, Gustav, and Hannes Eskebaek. "Real Time Vehicle Diagnostics Using Head Mounted Displays." Thesis, Linköpings universitet, Programvara och system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119657.
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This thesis evaluates how a head mounted display (HMD) can be used to increase usability compared to existing computer programs that are used during maintenance work on vehicles. Problems identified during a case study in a vehicle workshop are first described. As an attempt to solve some of the identified problems a prototype application using a HMD was developed. The prototype application aids the user during troubleshooting of systems on the vehicle by leading the mechanic with textual information and augmented reality (AR). Assessment of the prototype application was done by comparing it to the existing computer program and measuring error rate and time to completion for a predefined task. Usability was also measured using the System Usability Scale. The assessment showed that HMDs can provide higher usability in terms of efficiency and satisfaction. Furthermore, the thesis describes and discusses other possibilities and limitations that usage of HMDs and AR can lead to that were identified both from theory and during implementation.
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Felstead, Timothy James. "The use of a roadside remote sensing device to encourage voluntary vehicle emissions related maintenance." Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439356.
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Berlin, Daniel. "Multi-class Supervised Classification Techniques for High-dimensional Data: Applications to Vehicle Maintenance at Scania." Thesis, KTH, Matematisk statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209257.
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In vehicle repairs, many times locating the cause of error could turn out more time consuming than the reparation itself. Hence a systematic way to accurately predict a fault causing part would constitute a valuable tool especially for errors difficult to diagnose. This thesis explores the predictive ability of Diagnostic Trouble Codes (DTC’s), produced by the electronic system on Scania vehicles, as indicators for fault causing parts. The statistical analysis is based on about 18800 observations of vehicles where both DTC’s and replaced parts could be identified during the period march 2016 - march 2017. Two different approaches of forming classes is evaluated. Many classes had only few observations and, to give the classifiers a fair chance, it is decided to omit observations of classes based on their frequency in data. After processing, the resulting data could comprise 1547 observations on 4168 features, demonstrating very high dimensionality and making it impossible to apply standard methods of large-sample statistical inference. Two procedures of supervised statistical learning, that are able to cope with high dimensionality and multiple classes, Support Vector Machines and Neural Networks are exploited and evaluated. The analysis showed that on data with 1547 observations of 4168 features (unique DTC’s) and 7 classes SVM yielded an average prediction accuracy of 79.4% compared to 75.4% using NN.The conclusion of the analysis is that DTC’s holds potential to be used as indicators for fault causing parts in a predictive model, but in order to increase prediction accuracy learning data needs improvements. Scope for future research to improve and expand the model, along with practical suggestions for exploiting supervised classifiers at Scania is provided. keywords: Statistical learning, Machine learning, Neural networks, Deep learning, Supervised learning, High dimensionalityMånga gånger i samband med fordonsreparationer är felsökningen mer tidskrävande än själva reparationen. Således skulle en systematisk metod för att noggrant prediktera felkällan vara ett värdefullt verktyg för att diagnostisera reparationsåtgärder. I denna uppsats undersöks möjligheten att använda Diagnostic Trouble Codes (DTC:er), som genereras av de elektroniska systemen i Scanias fordon, som indikatorer för att peka ut felorsaken. Till grund för analysen användes ca 18800 observationer av fordon där både DTC:er samt utbytta delar kunnat identifieras under perioden mars 2016 - mars 2017. Två olika strategier för att generera klasser har utvärderats. Till många av klasserna fanns det endast ett fåtal observationer, och för att ge de prediktiva modellerna bra förutsättningar så användes endast klasser med tillräckligt många observationer i träningsdata. Efter bearbetning kunde data innehålla 1547 observationer 4168 attribut, vilket demonstrerar problemets höga dimensionalitet och gör det omöjligt att applicera standard metoder för statistisk analys på stora datamängder. Två metoder för övervakad statistisk inlärning, lämpliga för högdimensionell data med multipla klasser, Södvectormaskiner (SVM) samt Neurala Nätverk (NN) implementeras och deras resultat utvärderas. Analysen visade att på data med 1547 observationer av 4168 attribut (unika DTC:er) och 7 klasser kunde SVM prediktera observationer till klasserna med 79.4% noggrannhet jämfört med 75.4% för NN. De slutsatser som kunde dras av analysen var att DTC:er tycks ha potential att användas för att indikera felorsaker med en prediktiv modell, men att den data som ligger till grund för analysen bör förbättras för att öka noggrannheten i de prediktiva modellerna. Framtida forskningsmöjligheter för att ytterligare förbättra samt utveckla modellen, tillsammans med förslag för hur övervakade klassificerings modeller kan användas på Scnaia har identifierats.
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Smith, John Ethan. "Analysis of the costs and benefits of the USMC Light Armored Vehicle Depot Maintenance (IROAN) Program." Monterey, California. Naval Postgraduate School, 2006. http://hdl.handle.net/10945/10098.
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MBA Professional ReportThe Inspect Repair Only As Necessary (IROAN) program is a depot level maintenance program designed to improve the operational availability of Light Armored Vehicles in the Marine Corps inventory. the policy for assigning vehicles to the IROAN program is based on age, mileage and operating hours, with the primary criteria being time since last Iroan cycle. A cost benefit analysis was conducted using historical readiness reporting to determine if the current policy is the most cost effective among reasonable alternatives. Research indicates that the LAV fleet is actually managed on an eight year cycle, with vehicles from the operating forces receiving depot maintenance more frequently. Indications are that the average time between depot maintenance for operating forces is only slightly more frequent that the optimal timing of seven years. In the course of this research it became clear that the fragmented nature of USMC vehicle maintenance data makes performing these types of studies time-consuming and expensive. Consequently the difficulties in obtaining relevant data limit the quality of information available to support the Program Manager's decisions. l.
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Lidgren, Albin. "Concept Study and Design of a New Torque Calibration Rig." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-65712.
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When buying a new car today, the customer often expects to get a vehiclewith high quality. Each vehicle or engine should therefore be checked toassure quality. The same goes for clutches and couplings. A powerful enginebecomes useless when a clutch slips. Reliable torque measurement istherefore essential to the automotive industry. The herewith Bachelor thesisproposes a new torque calibration rig for online torque measurement in couplingapplications.The concept encompasses a servo motor with its associated electronics, agearbox to create the high torques (3 kNm), a reference torque transducer,and mounting elements or adapters. From the concept generation phase, thethesis includes CAD-models of the torque calibration rig with mathematicalmodels leading to the calculation of the measurement uncertainty of the calibrationsystem.This work was performed at BorgWarner PowerDrive Systems AB in Landskronaduring eight weeks; the two remaining weeks were completed in Lulea.
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Rezvanizaniani, Seyed Mohammad. "Probabilistic Based Classification Techniques for Improved Prognostics Using Time Series Data." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1428048932.
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Niedecken, Timon. "Optimized maintenance budget planning for DB Cargo locomotives." Thesis, KTH, Spårfordon, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299366.
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In a regional railway signalling system, object controllers are the devices responsible for controlling Track Side Equipment and act as interfaces for TSE with the interlocking computer and the Traffic control system. However, associated cabling (signal and power cabling) and civil works pose a major capital investment and it is a source of significant Capital and Operational expenses, particularly in rural areas, where accessibility andconnectivity to power grid and to the interlocking are a problem. Furthermore, cables/signalling equipment are exposed to sabotage and theft in such areas. This can increase the total Life Cycle Cost even further. The Shift2Rail research programme, which was initiated by the European Union and railway stakeholders, tries to address this issue, and revamp the Object Controller concept through the project “TD2.10 Smart radio connectedwayside object controller”, where the aim is to develop a Smart Wayside Object Controller (SWOC). A SWOC is capable of wireless communication between central interlocking and TSE as well as decentralization of interlocking logic. These innovations can reduce the cabling required, increase the availability of diagnostic data, thus reducing maintenance and operational costs and can lead to power saving by utilizing local power sources. The most important impact of the SWOC is a significant reduction of CAPEX, OPEX and of total LCC for an installation utilizing SWOCs, instead of typical OCS. This work focuses on estimating the LCC of a SWOC system and to compare it with a conventional OCS by developing an LCC model that covers both cases, as well as to use this model to examine when it is more profitable to implement a SWOC, instead of an OCS system. This is done by utilizing LCC analysis and combining a variety of methods in a parametric study. To that extend, a thorough analysis of a modern regional railway signallingsystem, as well as the basis for LCCA are being discussed. At the same time, both OC and SWOC systems are being described and factors affecting their cost discussed. The methodology is comprised of the LCC modelling part as well as the collection of methods and techniques used to calculate the LCC of OC/SWOC systems and to estimate the costs of different sub-models and parameters of the process. For the modelling process, the station of Björbo was chosen, which operates under ERTMS-R system, but for the sake of the analysis it is assumed that the typical base system in place is an OCS and together withthe existing track layout and equipment it is used as the basis of the analysis. Finally, the formed LCC model is being used in a parametric study to examine how the LCC is affected by using OC or SWOC as well as how LCC responds to changes in parameters such as number of OC/SWOC, traffic density and local power installation cost for the Björbo station.I ett regionalt järnvägssignalsystem är utdelar de enheter som ansvarar för att kontrollera spårutrustning och fungerar de som gränsyta för spårutrustning med ställverksdatorn och tågtrafikledning systemet. Dock, tillhörande kablar (signalkablar ock kraftkablar), samt anläggningsinfrastruktur utgör en stor kapitalinvestering och de är en källa till märkbar kapitalkostnad och driftskostnader, särskilt på landsbygdsområden, där tillgänglighet och anslutning till elnätet och ställverket är problematisk. Dessutom, kablar och signalutrustning utsätts för stöld och sabotage i sådana områden. Detta kan öka den totala livscykelkostnaden ytterligare. Shift2rail forskningsprogram, som genomförs av EU och järnvägsintressenter, försöker att ta itu med problemet och modernisera utdelar konceptet genom projektet “TD2.10 Smart Radio Connected Wayside Object Controller”, där målet är att utveckla en Smart Spårutrustning Utdelar, så kallade SWOC. En SWOC har kapacitet för trådlös kommunikation mellan central ställverket och spårutrustning, samt decentralisering av satällverkslogiken. Dessa innovationer kan minska nödvändig kabeldragning, öka tillgängligheten av diagnostiska data, vilket minskar underhålls- och driftskostnader och kan leda till energibesparing genom att använda lokala kraftkällor. Den viktigaste effekten av SWOC är en betydande minskning av kapitalkostnader, driftskostnader och totala livscykelkostnaden för en installation som använder SWOC istället för typiska utdelningsystemet. Detta examensarbete fokuserar på att uppskatta LCC för ett SWOC-system och jämföra det med en konventionell utdelingsystem genom att utveckla en LCC-modell som täcker båda fallen, samt att använda denna modell för att undersöka när det är mer lönsamt att implementera en SWOC istället av ett typiskt utdelingsystem. Detta görs genom att använda LCC-analys och kombinera en mängd olika metoder i en parametrisk studie. För att göradetta genomförs en grundlig analys av ett modernt regionalt järnvägssignalsystem, samt grunden för livscykelanalys. Samtidigt beskrivs både ett typiskt utdelingssystem - och SWOC-system samt faktorer som påverkar deras kostnad deskuteras. Metoden består av LCC-modelleringsdelen samt insamling av metoder och tekniker som används för att beräkna LCC för OC / SWOC-system och för att uppskatta kostnaderna för olika delmodeller och parametrar för processen. För modelleringsprocessen valdes stationen i Björbo, som arbetar under ERTMS-R-systemet, men för analysens skull antas att det typiska bassystemet på plats är en typisk OCS och tillsammans med befintlig planritning ochkabelplan är används som grund för analys. Slutligen används den bildade LCC-modellen i en parametrisk studie för att undersöka hur LCC påverkas genom att använda OC eller SWOC samt hur LCC reagerar på förändringar i parametrar såsom antal OC / SWOC, trafiktäthet och lokala kraftinstallationskostnader för Björbo-stationen.
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Nyström, Olof, and Caroline Pettersson. "Utvärdering och rekommendation av uppföljningsprogram för flygplanunderhåll : för Täby Air Maintenance." Thesis, Mälardalen University, Department of Mathematics and Physics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-249.
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By today’s date there are a lot of companies that are in great need of restructuring their paperwork in a more organized way. This can be excellent arranged with the help of properly constructed computer software. The aviation industry is no exception, but actually a good example of this. Täby Air Maintenance (TAM) is a company which is situated in Örebro. Their main business is aircraft maintenance on a variety of aircraft models. TAM has so far handled their work by hand or with the help of a majority of small computer programmes. The information has now become too abundant and the different kinds of software being used are no longer a working tool for the company. There is therefore a demand for an exhaustive programme which has the capacity to take care of all parts in logistics and production. The purpose is to examine and evaluate three different makes of software and form a recommendation to TAM of which one suits their needs the best. The software was Airsoft, MX System and System Airline Management (SAM). The evaluation has been performed with the help of demo versions of the programmes, manuals and support from contacts at the different manufacturers. The programmes were initially dealt with one at a time and then compared towards each other and towards the demands from TAM. The software which in the end was recommended was SAM, and the decision was based on a number of reasons. The main reason was the user friendliness of the software - the fact that its logical structure makes it easy for its user to swiftly understand the concept and thus learn how to use it quickly. This results in profits, both in time and money.
Idag är många företag i trängande behov av att strukturera upp sitt pappersarbete på ett mer ordnat sätt. Detta kan ske på ett effektivt sätt med ett anpassat och ändamålsenligt strukturerat datorprogram. Flygbranschen är inget undantag, snarare ett bra exempel på detta. Täby Air Maintenance (TAM) är ett företag som är beläget i Örebro och utför underhåll på flygplan i varierande storlek. TAM har hittills skött arbetet för hand och med hjälp av ett flertal mindre datorprogram. Informationen har dock blivit alldeles för omfångsrik och de olika programmen är inte längre ett fungerande instrument för verksamheten. Det krävs därför ett heltäckande program som har kapaciteten att ta hand om alla delar, såväl logistik som produktion. Syftet är att undersöka tre olika program och ge en rekommendation på det som passar företaget bäst. Programmen är Airsoft, MX System och System Airline Management (SAM). Undersökningen har utförts med hjälp av demoversioner, manualer och stöd från kontaktpersoner hos tillverkarna. Programmen undersöktes först var för sig och därefter jämfördes de mot varandra och mot TAMs krav. Det program som rekommenderades var SAM. Detta beror på en mängd orsaker, där den främsta orsaken var programmets användarvänlighet - det faktum att dess logiska uppbyggnad gör det lätt för användaren att snabbt kunna sätta sig in i strukturen och därmed lättare kunna lära sig att använda det. Detta i sin tur ger vinster i både tid och pengar.
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Matsumoto, Tsuyoshi. "Study of Long Span Bridge Design Based on Long Term Maintenance in Developing Countries." Kyoto University, 2020. http://hdl.handle.net/2433/253250.
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Karlsson, Henrik. "Monitoring Vehicle Suspension Elements Using Machine Learning Techniques." Thesis, KTH, Spårfordon, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262916.
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Condition monitoring (CM) is widely used in industry, and there is a growing interest in applying CM on rail vehicle systems. Condition based maintenance has the possibility to increase system safety and availability while at the sametime reduce the total maintenance costs.This thesis investigates the feasibility of using condition monitoring of suspension element components, in this case dampers, in rail vehicles. There are different methods utilized to detect degradations, ranging from mathematicalmodelling of the system to pure "knowledge-based" methods, using only large amount of data to detect patterns on a larger scale. In this thesis the latter approach is explored, where acceleration signals are evaluated on severalplaces on the axleboxes, bogieframes and the carbody of a rail vehicle simulation model. These signals are picked close to the dampers that are monitored in this study, and frequency response functions (FRF) are computed between axleboxes and bogieframes as well as between bogieframes and carbody. The idea is that the FRF will change as the condition of the dampers change, and thus act as indicators of faults. The FRF are then fed to different classificationalgorithms, that are trained and tested to distinguish between the different damper faults.This thesis further investigates which classification algorithm shows promising results for the problem, and which algorithm performs best in terms of classification accuracy as well as two other measures. Another aspect explored is thepossibility to apply dimensionality reduction to the extracted indicators (features). This thesis is also looking into how the three performance measures used are affected by typical varying operational conditions for a rail vehicle,such as varying excitation and carbody mass. The Linear Support Vector Machine classifier using the whole feature space, and the Linear Discriminant Analysis classifier combined with Principal Component Analysis dimensionality reduction on the feature space both show promising results for the taskof correctly classifying upcoming damper degradations.Tillståndsövervakning används brett inom industrin och det finns ett ökat intresse för att applicera tillståndsövervakning inom spårfordons olika system. Tillståndsbaserat underhåll kan potentiellt öka ett systems säkerhet och tillgänglighetsamtidigt som det kan minska de totala underhållskostnaderna.Detta examensarbete undersöker möjligheten att applicera tillståndsövervakning av komponenter i fjädringssystem, i detta fall dämpare, hos spårfordon. Det finns olika metoder för att upptäcka försämringar i komponenternas skick, från matematisk modellering av systemet till mer ”kunskaps-baserade” metodersom endast använder stora mängder data för att upptäcka mönster i en större skala. I detta arbete utforskas den sistnämnda metoden, där accelerationssignaler inhämtas från axelboxar, boggieramar samt vagnskorg från en simuleringsmodellav ett spårfordon. Dessa signaler är extraherade nära de dämpare som övervakas, och används för att beräkna frekvenssvarsfunktioner mellan axelboxar och boggieramar, samt mellan boggieramar och vagnskorg. Tanken är att frekvenssvarsfunktionerna förändras när dämparnas skick förändras ochpå så sätt fungera som indikatorer av dämparnas skick. Frekvenssvarsfunktionerna används sedan för att träna och testa olika klassificeringsalgoritmer för att kunna urskilja olika dämparfel.Detta arbete undersöker vidare vilka klassificeringsalgoritmer som visar lovande resultat för detta problem, och vilka av dessa som presterar bäst med avseende på noggrannheten i prediktionerna, samt två andra mått på algoritmernasprestanda. En annan aspekt som undersöks är möjligheten att applicera dimensionalitetsminskning på de extraherade indikatorerna. Detta arbete undersöker också hur de tre prestandamåtten som används påverkas av typiska förändringar i driftsförhållanden för ett spårfordon såsom varierande exciteringfrån spåret och vagnkorgsmassa. Resultaten visar lovande prestanda för klassificeringsalgoritmen ”Linear Support Vector Machine” som använder hela rymden med felindikatorer, samt algoritmen ”Linear Discriminant Analysis” i kombination med ”Principal Component Analysis” dimensionalitetsreducering.
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Garza, Luis. "A case study of the application of reliability centered maintenance (RCM) in the acquisition of the advanced amphibious assault vehicle (AAAV)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Dec%5FGarza.pdf.
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Hawari, Haitham M. "Minimising track degradation through managing vehicle/track interaction." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16366/.
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The rate at which a railway track deteriorates depends on the response of the track under different static and repeated dynamic forces. These wheel/rail forces lead to imperfections in the rail surface and deviation in track geometry alignment. The wheel/rail forces are dependent upon the quality of maintenance of the characteristics of both train and track. If train components such as wheelsets and suspensions are maintained to a high standard, less dynamic forces are generated at the wheel/rail interface and less damage is caused over time. Therefore, the amount and cost of maintenance of track are reduced. However, there is little known about how the characteristics of train components affect time-dependent track degradation. Track degradation through deviation of track from its ideal position has the most effect on maintenance costs. Therefore, the present research aims to investigate this track degradation and improve understanding of the effects of train characteristics (such as train mass and speed, suspension stiffness and damping) on railway tracks. The research is conducted by looking into the relationship between wheel/rail forces and track degradation on one hand and between wheel/rail forces and train characteristics on the other hand, with the objective of assisting in managing vehicle/track interaction in order to minimise track degradation. This aim is achieved by investigating the above two relationships to attain the desired relationship between track degradation and train characteristics. The research focuses on wheel/rail vertical forces (both amplitudes and frequencies), vertical track alignment (longitudinal vertical profile), and rail head defects. The study started by collecting wheel/rail vertical forces data in addition to data on vertical track degradation under sustained traffic loads on a heavy haul railway section of track in Central Queensland. Also, five years of degradation and maintenance history data were collected on three other test sections of railway track under variety of traffic conditions and loads in Central Queensland. There were four main analyses of this data employed to probe the study. The first analysis was performed by examining the track degradation history data. The standard deviation method was used in this first analysis to acquire the rate of deterioration in terms of its relationship to track profile (roughness). The second analysis was accomplished by correlating the vertical wheel/rail forces to both vertical track profile and rail roughness using signal processing principles and a function know as coherence. The third analysis was carried out by using the computer simulation software NUCARS to obtain the link between wheel/rail forces and the deterioration of the vertical track profile. The fourth analysis was achieved by combining the results obtained from the above three analyses to acquire the rate of track deterioration in terms of its relationship to varying train characteristics. The first analysis mentioned above quantified the relationship between the level of roughness of the track and rate at which that roughness deteriorated. An important outcome of this relationship is that there is a threshold of roughness below which track deterioration is minimal. The track maintenance planners can now use that threshold for cost effective targeting of tamping activities. The correlation study between track roughness and wheel/rail forces using the coherence function found, surprisingly, that the overall deterioration of the track roughness, in the absence of frequencies of forces above 30 Hz, is due to the so-called quasi-static lower frequency oscillations of dynamic forces. This conclusion together with the relationship between vehicle characteristics and track forces, established in the analyses above, has significant implications for the design of wagon bogies and for charges track owners might levy on trains using their tracks. This research is part of a larger Rail CRC project 11/4 called 'Enhancing the Optimisation of Maintenance/Renewal' being carried out in the School of Urban Development in Queensland University of Technology.
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Mogrovejo, Carrasco Daniel Estuardo. "Effect of Air Temperature, Vehicle Speed, and Pavement Surface Aging on Tire/Pavement Noise Measured with On-Board Sound Intensity Methodology." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/19261.
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The study of the traffic noise as an environmental impact, the search for solutions to this problem, and the development of noise measurement methodologies that help in the search of these solutions, is now a fundamental responsibility for the transportation industry.
So, in line with this responsibility, consistent work was made with focus on tire/pavement noise measured over different pavement surfaces, and under different environmental conditions, and different speeds. In a parallel way, work was conducted for the development, improvement, and practical use of the On- Board Sound Intensity (OBSI) methodology for tire/pavement noise measurements.
The first part of this thesis shows the results of field experimentation about the influence of external factors like air temperature and vehicle speed over the tire/pavement noise measured with the OBSI methodology. Temperatures from 40 to 90"F were targeted, and speeds from 35 mph to 60 mph (range in which tire/pavement noise becomes predominant for the overall vehicle noise) were tested. For this work a series of seasonal field tests were conducted on a primary road in Virginia over various months. The results were analyzed to quantify the variation of tire/pavement noise with respect to the air temperature and test speed, and therefore to find correction factors for this variables in order to normalize the data taken under different conditions.
In the second part of this thesis, the study of tire/pavement noise over different surfaces and measured over a timeframe of three seasons is presented. This part presents results about noise reduction potentials of two proposed "quiet" concrete technologies and 3 proposed "quiet" asphalt surfaces when compared with one another, and with control sections. Also the second part of the thesis includes results about the susceptibility of the proposed surfaces to external factors such as: aging (three seasons involved), air temperature differentials and winter maintenance.
In general, the findings show trends that tire/pavement noise slightly decreases as air temperature increases. A gradient of approximately -0.05 dBA/"F was found. It was found as well that tire/pavement noise increases an average of 2.5 dBA for every 10 mph of increased speed.
The statistical analysis results for the second part of the thesis shows that all proposed concrete surfaces and asphalt surfaces present benefits in terms of noise reduction, For the asphalt surfaces, it was found that more voids in the surface helps to absorb the noise. In addition, the rubber modified mixes show an improved noise reduction potential. Air temperature normalization was performed an a statistical analysis was conducted; it was found that air temperature has a significant influence in the noise measurements especially for the first months of use. Finally it was found that there is a slightly increase in noise over time after the first months of use.Master of Science
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Supnithadnaporn, Anupit. "Three essays in program evaluation the case of Atlanta inspection and maintenance program /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29770.
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Thesis (Ph.D)--Public Policy, Georgia Institute of Technology, 2009.Committee Chair: Noonan, Douglas; Committee Member: Castillo, Marco; Committee Member: Chang, Michael; Committee Member: Cozzens, Susan; Committee Member: Rodgers, Michael. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Stepien, Hubert, and Martin Bilger. "Diverse Time Redundant Triplex Parallel Convolutional Neural Networks for Unmanned Aerial Vehicle Detection." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-54596.
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Safe airspace of airports worldwide is crucial to ensure that passengers, workers, and airplanes are safe from external threats, whether malicious or not. In recent years, several airports worldwide experienced intrusions into their airspace by unmanned aerial vehicles. Based on this observation, there is a need for a reliable detection system capable of detecting unmanned aerial vehicles with high accuracy and integrity. This thesis proposes time redundant triplex parallel diverse convolutional neural network architectures trained to detect unmanned aerial vehicles to address the aforementioned issue. The thesis aims at producing a system capable of real-time performance coupled with previously mentioned networks. The hypothesis in this method will result in lower mispredictions of objects other than drones and high accuracy compared to singular convolutional neural networks. Several improvements to accuracy, lower mispredictions, and faster detection times were observed during the performed experiments with the proposed system. Furthermore, a new way of interpreting the intersection over union results for all neural networks is introduced to ensure the correctness and reliability of results. Lastly, the system produced by this thesis is analyzed from a dependability viewpoint to provide an overview of how this contributes to dependability research.
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Schoultz, Joakim, and Tobias Wikberg. "Konstruktion och vidareutveckling av SIRIUS skidbalk." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-186679.
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Denna kandidatrapport behandlar ett arbete resulterande i en ökning av hållfastheten hos en skidbalk ingående i bandvagnen BvS10. Projektet har utförts på uppdrag av BAE Systems Hägglunds under deras SIRIUS-samarbete med Luleå tekniska universitet. Inom SIRIUS har många utvecklingsprojekt startats, varav ett är E-TED dit det här arbetet hör. Balken har tappat avsevärd hållfasthet då hål utformats i dess yttre sida för att rymma komponenter. Detta har gjorts av anledningar utvecklade inom E-TED. Syftet var därför att utveckla en konceptuell och användbarskidbalk för bandvagnen med målsättningen att erhålla en lika bra eller bättre hållfasthet relativt ursprungsbalken. För att nå målet itererades arbetet mellan finita elementmetoden (FEM) och computer-aided design (CAD) i programmen CATIA V5, ANSA, ABAQUS och META för utveckling av koncept. Itereringen resulterade i två konceptbalkar, varav den sista var fördelaktigast. CATIA brukades för CAD och de resterande programmen brukades respektive som förbehandlare, problemlösare och efterbehandlare för FEM. Av dessa tre utfördes de två första med hjälp av beräkningsavdelningen på BAE Systems Hägglunds och det sista utfördes av författarna. Ursprungs- och konceptbalkarna testades med fem lastfall motsvarande de extremaste förhållanden som uppmätts vid körning av bandvagnen. Förstärkningarna implementerades därefter baserad på teori gällande böj- och vridmotstånd för homogena balkars kvadratiska- och rektangulära tvärsnitt. Spänningsanalys av den slutgiltiga konceptbalken uppvisade effektivspänningar överskridande materialets sträckgräns för tre av lastfallen. För de två mest problematiska av dessa tre fall utformades en analys av kvarvarande plastisk töjning respektive deformation. Detta påvisade att kvarvarande plastisk töjning respektive deformation var i samma storleksordning som vid tidigare undersökningar av idag driftsatta skidbalkar. Alltså drogs slutsatsen att det är möjligt att skapa en SIRIUS-skidbalk med minst lika bra hållfasthet som ursprungsbalken samt att slutgiltiga konceptbalken, ur ett hållfasthetsperspektiv, är redo för användning.This bachelor report covers a work resulting in an increased strength of a skid girder located on the tracked vehicle BvS10. The project was performed on behalf of BAE Systems Hägglunds under their SIRIUS-collaboration with Luleå University of Technology. Many development projects have been started within SIRIUS, one of these is E-TED where this work belongs. The skid girder has lost considerable strength due to the implementation of holes in its outer side to make room for components. This has been done due to reasons developed within E-TED. The purpose of this project was therefore to develop a conceptual and useable skid girder with the goal to increase the strength to equal or higher levels relative to the original skid girder. To achieve the goal the work iterated between finite element method (FEM) and computer-aided design (CAD) in the software’s CATIA V5, ANSA, ABAQUS and META to develop the concepts. The iteration resulted in two conceptual skid girders of which the last was found more favorable than the other. CATIA was utilized for CAD and the remaining programs were respectively used as pre-processor, solver and post-processor for FEM. The first two of these three were executed with helpfrom the calculations department at BAE Systems Hägglunds and the last one was performed bythe authors. The original and conceptual beams’ were tested with five load cases corresponding to the most extreme conditions measured while driving the tracked vehicle. Reinforcements were thereafter implemented based on theory regarding bending and torsion resistance of homogenous beams’ with squared and rectangular cross-sections. The stress analysis of the final conceptual skid girder demonstrated von Mises stresses exceeding the material’s yield point for three of the load cases. An analysis of remaining plastic strain and deformation were designed for the two most problematic of these three cases. This showed that the remaining plastic strain and deformation were on the same order of magnitude as thoseo btained in previous investigations of operating skid girders today. Thus the conclusion was drawn that it is possible to create a SIRIUS skid girder with equal or better strength than the original skidgirder and that the final conceptual skid girder, from a perspective of strength, is ready foroperation.
SIRIUS
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Hugo, Daniel. "Haul road defect identification and condition assessment using measured truck response." Diss., University of Pretoria, 2005. http://upetd.up.ac.za/thesis/available/etd-07162008-092104/.
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Håkonsen, Christian, and Mikael Berkelund. "Development of a new drawing system for STS." Thesis, Mälardalen University, School of Innovation, Design and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-618.
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An engineering firm which handles and constructs drawings needs well defined routines and structures which should be homogeneous through all the different departments. A common drawing system results in better quality and cooperation between the departments.
SAS Technical Services (STS) did not have a common drawing system which had led to development of different routines in the different regions and departments. Requested was development of new routines regarding engineering drawings, such as drawing numbering structure, revision and subscription routines, which standards to adhere to, custom made drawing templates and management of the drawings with belonging documents.
Each requested task was broken into minor tasks and analyzed. Solutions by different leading engineering companies were used for comparison and ideas.
All the tasks were collected and organized in one single document which is the result of the thesis; a drawing instruction.
The drawing instruction will after a learning phase ease the work for the STS engineers as all necessary information can be found in one single place. Also, work with contractors will be time-saving as the instruction can be handed out for guidance.
En ingenjörsfirma som hanterar och skapar mängder med ritningar behöver väldefinierade rutiner och strukturer som är homogena genom hela bolaget. Ett gemensamt ritningssystem resulterar i bättre kvalitet och bättre samarbete mellan de olika avdelningarna.
SAS Technical Services (STS) hade inte ett gemensamt ritningssystem vilket har lett till att de olika avdelningarna har utvecklat olika rutiner rörande ritningar. Önskemålet var utvecklande av nya rutiner rörande ingenjörsritningar såsom ritningsnumreringsstruktur, revisions- och prenumerationsrutiner, vilka standarder som skall följas, egna ritningsmallar och skötsel av ritningar med tillhörande dokument.
Varje önskad uppgift blev uppdelad i mindre uppgifter och analyserad. Lösningar från olika ledande ingenjörsbolag användes för jämförelse och idéer.
Alla uppgifterna samlades och organiserades i ett och samma dokument som är resultatet av detta arbete; en ritningsinstruktion.
Ritningsinstruktionen kommer efter en inlärningsfas underlätta arbetet för ingenjörerna på STS eftersom all nödvändig information nu finns på ett och samma ställe. Arbeten med entreprenörer vill också bli underlättande eftersom instruktionen kan delas ut för vägledning.
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Lundgren, Andreas. "Data-Driven Engine Fault Classification and Severity Estimation Using Residuals and Data." Thesis, Linköpings universitet, Fordonssystem, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165736.
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Recent technological advances in the automotive industry have made vehicularsystems increasingly complex in terms of both hardware and software. As thecomplexity of the systems increase, so does the complexity of efficient monitoringof these system. With increasing computational power the field of diagnosticsis becoming evermore focused on software solutions for detecting and classifyinganomalies in the supervised systems. Model-based methods utilize knowledgeabout the physical system to device nominal models of the system to detect deviations,while data-driven methods uses historical data to come to conclusionsabout the present state of the system in question. This study proposes a combinedmodel-based and data-driven diagnostic framework for fault classification,severity estimation and novelty detection. An algorithm is presented which uses a system model to generate a candidate setof residuals for the system. A subset of the residuals are then selected for eachfault using L1-regularized logistic regression. The time series training data fromthe selected residuals is labelled with fault and severity. It is then compressedusing a Gaussian parametric representation, and data from different fault modesare modelled using 1-class support vector machines. The classification of datais performed by utilizing the support vector machine description of the data inthe residual space, and the fault severity is estimated as a convex optimizationproblem of minimizing the Kullback-Leibler divergence (kld) between the newdata and training data of different fault modes and severities. The algorithm is tested with data collected from a commercial Volvo car enginein an engine test cell and the results are presented in this report. Initial testsindicate the potential of the kld for fault severity estimation and that noveltydetection performance is closely tied to the residual selection process.
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Wileman, Andrew John. "An investigation into the prognosis of electromagnetic relays." Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/13665.
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Electrical contacts provide a well-proven solution to switching various loads in a wide variety of applications, such as power distribution, control applications, automotive and telecommunications. However, electrical contacts are known for limited reliability due to degradation effects upon the switching contacts due to arcing and fretting. Essentially, the life of the device may be determined by the limited life of the contacts. Failure to trip, spurious tripping and contact welding can, in critical applications such as control systems for avionics and nuclear power application, cause significant costs due to downtime, as well as safety implications. Prognostics provides a way to assess the remaining useful life (RUL) of a component based on its current state of health and its anticipated future usage and operating conditions. In this thesis, the effects of contact wear on a set of electromagnetic relays used in an avionic power controller is examined, and how contact resistance combined with a prognostic approach, can be used to ascertain the RUL of the device. Two methodologies are presented, firstly a Physics based Model (PbM) of the degradation using the predicted material loss due to arc damage. Secondly a computationally efficient technique using posterior degradation data to form a state space model in real time via a Sliding Window Recursive Least Squares (SWRLS) algorithm. Health monitoring using the presented techniques can provide knowledge of impending failure in high reliability applications where the risks associated with loss-of-functionality are too high to endure. The future states of the systems has been estimated based on a Particle and Kalman-filter projection of the models via a Bayesian framework. Performance of the prognostication health management algorithm during the contacts life has been quantified using performance evaluation metrics. Model predictions have been correlated with experimental data. Prognostic metrics including Prognostic Horizon (PH), alpha-Lamda (α-λ), and Relative Accuracy have been used to assess the performance of the damage proxies and a comparison of the two models made.
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Pacheco, Roman Oscar. "Evaluation of Finite Element simulation methods for High Cycle Fatigue on engine components." Thesis, Linköpings universitet, Mekanik och hållfasthetslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148779.
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This document reflects the results of evaluating three computational methods to analyse the fatigue life of components mounted on the cylinder block; two currently in use at Scania and one that has been further developed from its previous state. Due to the cost of testing and the exponential increase in computational power throughout the years, the cheaper computational analyses have gained in popularity. When a component is mounted in a fairly complex assembly such as an engine, simplifications need to be made in order to make the analysis as less expensive as possible while keeping a high degree of accuracy. The methods of Virtual Vibrations, VROM and VFEM have been evaluated and compared in terms of accuracy, computational cost, user friendliness and general capacities. Additionally, the method VFEM has been further developed and improved from its previous state. A in-depth investigation regarding the differences of the methods has been conducted and improvements to make them more efficient are suggested herein. The reader can also find a decision matrix and recommendations regarding which method to use depending on the general characteristics of the component of interest and other factors. Two components, which differ in complexity and mounting nature, have been used to do the research.
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Hu, Xiaowei. "A study of nozzle jet application to winter maintenance vehicles." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447630.
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Eker, Ömer F. "A hybrid prognostic methodology and its application to well-controlled engineering systems." Thesis, Cranfield University, 2015. http://dspace.lib.cranfield.ac.uk/handle/1826/9269.
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This thesis presents a novel hybrid prognostic methodology, integrating physics-based and data-driven prognostic models, to enhance the prognostic accuracy, robustness, and applicability. The presented prognostic methodology integrates the short-term predictions of a physics-based model with the longer term projection of a similarity-based data-driven model, to obtain remaining useful life estimations. The hybrid prognostic methodology has been applied on specific components of two different engineering systems, one which represents accelerated, and the other a nominal degradation process. Clogged filter and fatigue crack propagation failure cases are selected as case studies. An experimental rig has been developed to investigate the accelerated clogging phenomena whereas the publicly available Virkler fatigue crack propagation dataset is chosen after an extensive literature search and dataset analysis. The filter clogging experimental rig is designed to obtain reproducible filter clogging data under different operational profiles. This data is thought to be a good benchmark dataset for prognostic models. The performance of the presented methodology has been evaluated by comparing remaining useful life estimations obtained from both hybrid and individual prognostic models. This comparison has been based on the most recent prognostic evaluation metrics. The results show that the presented methodology improves accuracy, robustness and applicability. The work contained herein is therefore expected to contribute to scientific knowledge as well as industrial technology development.
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Dale, Daniel R. M. Eng Massachusetts Institute of Technology. "Automated ground maintenance and health management for autonomous unmanned aerial vehicles." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41541.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 99-101).
Automated ground maintenance is a necessity for multi-UAV systems. Without such automation, these systems will become more of a burden than a benefit as human operators struggle to contend with maintenance operations for large numbers of vehicles. By creating autonomous UAV systems that can take care of themselves, human operators will be free to concentrate on higher level tasks such as using the information gathered by the system to direct future mission activities. This thesis describes the design, testing, construction, and usage of the first fully autonomous recharge system for small, battery-powered UAVs. This system was used to perform the first fully-autonomous quadrotor UAV long-term flight tests and to conduct multi-UAV mission management research. In addition, this thesis describes, to the best of our knowledge, the first landing and recharge of a UAV on a mobile recharge platform.
by Daniel R. Dale.
M.Eng.
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Wigren, Anna. "A Study on Condition-Based Maintenance with Applications to Industrial Vehicles." Thesis, Uppsala universitet, Avdelningen för systemteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-321528.
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The company CrossControl develops display computers for control systems in industrial vehicles which operate in rough environments. Currently, the system can detect and diagnose different faults but CrossControl would also like to predict upcoming failures by using Condition-Based Maintenance (CBM). CBM is a cost effective maintenance strategy where the health condition of the system is monitored and maintenance is only performed after a degradation in performance has been observed. This thesis work aims to investigate the possibilities of implementing CBM on CrossControl's system by studying the theory behind CBM and associated methods and by analysing real data from the system of one of CrossControl's customers. The results presented in this thesis consist of two literature studies and one case study. The first literature study introduces different types of maintenance and gives a detailed explanation of CBM. The second literature study contains a collection of methods used to estimate the Remaining Useful Life (RUL) of the system, which is an important step in CBM. The case study considers the twistlocks of Bromma Conquip's spreader system and serves as an example of how CBM can be used in practise and exemplifies some difficulties that can be encountered when implementing CBM. Finally, a discussion of the obtained results and some suggestions for future work and ideas for how CBM can be implemented on CrossControl's system are given.
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Lagnebäck, Robert. "Evaluation of wayside condition monitoring technologies for condition-based maintenance of railway vehicles /." Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1757/2007/18/.
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Lagnebäck, Robert. "Evaluation of wayside condition monitoring technologies for condition-based maintenance of railway vehicles." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18158.
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Luossavaara-Kiirunavaara AB (LKAB) is an iron ore mining company in Sweden that strives to be one of the leading suppliers of iron ore products. In the chain from mining to end customers, transportation efficiency plays a mayor role in the outcome of the company's total financial result. The transportation of the ore from the LKAB mines in Kiruna and Malmberget is made by trains to the harbors in Narvik and Luleå. The railway transportations are made by LKAB subsidiaries Malmtrafik i Kiruna AB (MTAB) on the Swedish side and Malmtrafikk AS (MTAS) on the Norwegian side. The efficiency of the railway transportation is therefore a key function in the LKAB mining operations. In a benchmarking, comparing the total operating efficiency, with other heavy haul railways around the world it became evident that the efficiency of the railway transportations at LKAB had potential for improvement. One of the factors with potential for improved efficiency was the maintenance strategy. There is an indication that a change from a time-based maintenance strategy to a condition-based maintenance strategy would increase the efficiency of the train operations. The purpose of this thesis is to study and analyze wayside condition monitoring equipment for railway vehicles, in order to support the implementation of a condition-based maintenance strategy. To fulfill the stated purpose, five case studies, supported by a literature study, have been performed. The five case studies have been conducted to increase the knowledge of the abilities of available wayside condition monitoring equipment as a support for condition-based maintenance of railway vehicles. The literature study focused on railway operations around the world with a particular focus on the development, deployment and use of wayside condition monitoring equipment. The literature study indicates that there is an increasing implementation and use of equipment for wayside condition monitoring of railway vehicles. Through the studies it has become evident that the direct interaction in the wheel and rail interface also creates a huge potential for savings on the infrastructure due to an implementation of wayside condition monitoring equipment for railway vehicles. The case studies highlight the need for different systems that complement each other by measuring different parameters. It is also important that the systems are integrated with existing systems and practices in order to exploit the potential benefits of the new technology. Furthermore, it is important to have a joint approach between both infrastructure owners and train operators in the deployment and use of wayside condition monitoring equipment, since the technology can support a condition-based maintenance strategy on both sides that could have a great impact on the efficiency of railway operations.Luossavaara-Kiirunavaara AB (LKAB) är ett Svenskt gruvbolag som bryter järnmalm. Man har som målsättning att bli en av de ledande leverantörerna i världen av järnmalmsprodukter. I kedjan från brytning till slutkund, spelar transporteffektivitet en avgörande roll i företagets totala ekonomiska resultat. Transporterna av malm från LKAB:s gruvor i Kiruna och Malmberget utförs med järnvägstransporter till utskeppningshamnar i Narvik och Luleå. Järnvägstransporterna utförs av LKAB:s dotterbolag Malmtrafik i Kiruna AB (MTAB) på den Svenska sidan och av Malmtrafikk AS (MTAS) på den Norska sidan. Järnvägs transporternas effektivitet är därför en nyckelfunktion i LKAB:s gruvbrytningsverksamhet. I en benchmarkingstudie utförd på den totala effektiviteten av verksamheten hos gruvverksamheter med tunga järnvägstransporter runt om i världen blev det uppdagat att det finns en potential att förbättra effektiviteten hos LKAB:s järnvägstransporter. En av faktorerna som har potential att förbättra effektiviteten är underhållsstrategin. Det finns tydliga indikationer på att en förändring från ett förutbestämt underhåll till ett tillståndsbaserat underhåll skulle kunna öka järnvägstransporternas effektivitet. Syftet med denna licentiat avhandling är att utvärdera tekniska system som kan placeras vid spåret och användas som tillstånds övervakande utrustning för järnvägsfordon för att stödja en implementering av en tillståndsbaserad underhållsstrategi.För att uppnå det utsatta syftet har fem fallstudier, samt en litteratur studie genomförts. De fem fallstudierna har utförts för att öka kunskapen om egenskaperna hos tillgänglig tillståndsövervakande utrustning för placering vid spåret som stöd för tillståndsbaserat underhåll av järnvägsfordon. Litteraturstudien har fokuserats på järnvägsverksamheter i runt om i världen med speciellt fokus på utveckling, utplacering och användande av spårbunden tillståndsövervakningsutrustning .Litteraturstudien indikerar att det pågår en ökande implementering och användning av tillståndsövervakande utrustning för järnvägsfordon. Genom studierna har det framkommit att den direkta interaktionen mellan hjul och räl också skapar en stor potential för besparingar på infrastrukturen med hjälp av en implementering av spårbunden tillståndsövervakande utrustning för järnvägsfordonen.Case studierna belyser nödvändigheten av att ha olika system som kan komplettera varandra genom att mäta olika parametrar. Det är också viktigt att systemen är integrerade med existerande system och metoder för att uppnå de potentiella fördelarna med den nya teknologin. Det är dessutom viktigt att ha ett gemensamt tillvägagångssätt mellan både infrastrukturägare och tågoperatörer i implementeringen och användandet av spårbunden tillståndsövervakande utrustning, eftersom teknologin kan stödja en tillståndsbaserad underhålls strategi för båda sidor, vilket kan ha stor positiv inverkan på järnvägsdriftens effektivitet.
Godkänd; 2007; 20070315 (ysko)
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Robert, Elodie. "Gestion de l'état de santé de véhicules pour la maintenance de flotte : prise en compte des contraintes opérationnelles et optimisation conjointe des maintenances et des missions." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAT098.
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Ces travaux de thèse traitent des problèmes de planification conjointe des opérations de maintenance et des missions pour des flottes de véhicules industriels. Le but est de développer une méthodologie permettant d’adapter la planification conjointe des maintenances et des missions en fonction de l’état de santé des véhicules mais également en fonction des caractéristiques des missions. Ces caractéristiques correspondent aux conditions de sévérité d’usage qui ont un impact important sur la dégradation du camion et doivent être prise en compte pour adapter au mieux la planification des opérations de maintenance en fonction de l’évolution de la dégradation. La mise en place d’une méthodologie d’aide à la décision pour gérer une flotte permettrait d’améliorer la productivité, de réduire les coûts de maintenance tout en utilisant au mieux la capacité de la flotte. Cependant, le problème de planification conjointe pour une flotte est un problème complexe à résoudre nécessitant de considérer trois dimensions. La première est de planifier conjointement les missions et les maintenances de façon statique. La seconde est d’intégrer, de façon dynamique, les informations de surveillance disponibles et les différents événements pouvant se produire pour mettre à jour le planning. La troisième dimension est la dimension flotte qui implique de gérer plusieurs véhicules en parallèle.La première étape consiste à planifier conjointement les activités de maintenance et les missions pour un camion dans un cas statique. On suppose alors qu’on connait toutes les missions à planifier et qu’aucune information de surveillance n’est disponible. Pour cela, on définit un modèle de dégradation du véhicule afin d’estimer sa durée de vie résiduelle pour prendre les décisions. C’est un modèle avec des valeurs de paramètres variables car le véhicule évolue dans des conditions de sévérité d’usage différentes en fonction des missions. Il est le point central pour mettre en place un algorithme de planification afin d’éviter les risques de panne trop importants. La planification est naturellement optimisée en fonction d’un critère basé soit sur les coûts de maintenance, soit sur les revenus d’exploitation.Une fois cette méthodologie définie, elle est complétée pour intégrer les informations relatives à la dégradation du véhicule, les occurrences de panne et les nouvelles missions qui peuvent demandées. Une approche dynamique pour résoudre le problème de planification pour un véhicule a donc été développée. Si une panne survient, le planning est mis à jour car il n’est plus adapté à l’évolution de la dégradation réelle du véhicule. De même, lorsque qu’une nouvelle mission est disponible, une mise à jour est indispensable car l’ordre de priorité des missions, défini par leurs dates limites de livraison, doit être pris en compte au plus vite pour éviter les pénalités de retard. En revanche, une information de dégradation peut avoir une influence variable sur le planning en cours. Il s’agit donc d’étudier la robustesse du planning pour éviter de changer trop souvent l’ordre des missions et les dates de maintenance.La dernière étape consiste à intégrer la dimension flotte dans la prise de décision. Ce n’est donc plus juste une question d’ordre des missions et de planification des maintenances au bon moment mais il faut également décider à quelle mission est attribuée à quel véhicule. La prise de décision dépend alors de l’état de la flotte. Une analyse de l’impact de la prise en compte de la dimension flotte dans le cas statique, puis dans le cas dynamique est menée.Des résultats de simulation permettent d’illustrer les méthodes développées et de montrer leur intérêt et les gains en termes de coûts qu’elles engendrentThis thesis work deals with the problems of joint scheduling for maintenance operations and missions for industrial vehicle fleets. The aim is to develop a methodology to adapt the joint scheduling of maintenance and missions according to the vehicles health state but also according to the missions features. These features correspond to the conditions of usage severity that have a significant impact on the truck deterioration and must be taken into account to adapt at best the maintenance operations schedule according to the deterioration evolution. The implementation of a decision support methodology to manage a fleet would improve productivity and reduce the maintenance costs while making the most of the fleet capacity. However, the joint scheduling problem for a fleet is a complex problem to solve and three main dimensions has to be considered. The first one is to jointly schedule missions and maintenance operations in a static case. The second one is to integrate the available monitoring information and the different events that can occur to update the schedule and treat the problem in a dynamic way. The third dimension is the fleet dimension that involves managing several vehicles in parallel.The first step is to jointly schedule the maintenance activity and the missions for a truck in a static case. It is assumed that all the missions to be performed are known and that no monitoring information is available. To do this, a vehicle deterioration model is defined to estimate its remaining useful lifetime to make decisions. It is a model with varying parameters since the vehicle operates under different conditions of usage severity according to the missions. It is the central point for setting up a scheduling algorithm to avoid any excessive risk of failure. The scheduling process is naturally optimized according to a criterion based on either the maintenance costs or the operating incomes.Once this methodology has been defined, it must be completed to include information on the vehicle deterioration, failure occurrences and new missions that may be requested. A dynamic approach has then been developed to solve the scheduling problem for a vehicle. If a breakdown occurs, the schedule must be updated because it is no longer adapted to the evolution of the current vehicle deterioration. Likewise, when a new mission is available, an update is essential because the priority order of the missions, defined by their deadlines, must be considered as soon as possible to avoid delay penalties. On the other hand, deterioration information can have a varying influence on the current schedule. Then, the schedule robustness has to be studied to avoid changing the mission order and the maintenance dates too often.The last step is to integrate the fleet dimension in the decision-making process. It is no longer just a question of mission order and timing for maintenance operations, but also of deciding which vehicle is assigned to which mission. The decision-making process then depends on the whole fleet. An analysis of the impact of considering the fleet dimension in the static case and then in the dynamic case is led.Simulation results are used to illustrate the developed methods and aim at showing their interest and the cost savings they generate
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Lesobre, Romain. "Modélisation et optimisation de la maintenance et de la surveillance des systèmes multi-composants - Applications à la maintenance et à la conception de véhicules industriels." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT022/document.
Full textAbstract:
Ces travaux de thèse traitent des problèmes de maintenance associés aux véhicules industriels. Ils se concentrent sur la planification des opérations de maintenance et sur le développement d'une méthodologie de conception pour la maintenance. Le but est de proposer une offre de maintenance personnalisée en fonction de chaque véhicule et capable de s'adapter aux contraintes des utilisateurs. Dans l'industrie du transport, ces contraintes se caractérisent par un nombre d'opportunités de maintenance limité et des immobilisations à fortes conséquences financières. Cette offre a vocation à garantir un niveau de disponibilité élevé tout en réduisant l'impact de la maintenance sur les coûts globaux d'exploitation. Dans ce cadre, la politique de maintenance développée vise à assurer, moyennant un certain risque, l'autonomie d'un système multi-composant sur des périodes d'opérations données. Pendant ces périodes, aucune opération de maintenance et aucune défaillance du système ne doivent venir perturber la réalisation des missions. A la fin de chaque période, la politique considérée évalue la nécessité d'une intervention de maintenance pour assurer la prochaine période avec un niveau de confiance spécifié. Lorsque la maintenance est jugée indispensable, des critères intégrant les coûts et l'efficacité de la maintenance sont introduits pour sélectionner les opérations à réaliser. Cette forme originale de regroupement dynamique s'appuie à la fois sur les modèles de fiabilité des composants, sur la structure fiabiliste du système et sur les informations de surveillance disponibles en ligne. Celles-ci se composent d'informations liées à l'état de santé des composants mais également à leurs conditions d'utilisation. La flexibilité du processus permet d'intégrer, dans la décision, des niveaux d'informations différents suivant les composants. Les paramètres de cette politique, à savoir la longueur de la période et le niveau de confiance, sont optimisés en fonction du coût total de maintenance. Ce coût, évalué sur un horizon fini, intègre les coûts directs associés aux opérations de maintenance et les coûts indirects engendrés par les immobilisations. Pour envisager une réduction significative des coûts d'exploitation du système, l'optimisation de la politique de maintenance seule ne suffit pas. Il est primordial de mener une réflexion plus large associant le système et sa maintenance dès la conception. Pour diriger cette réflexion, la méthodologie de conception proposée hiérarchise, à l'aide d'un facteur d'importance original, l'impact des composants sur les coûts d'exploitation. Différentes options de conceptions sont ensuite évaluées, par simulation, sur les composants jugés prioritaires. Les options retenues conduisent à réduire les coûts globaux d'exploitation. Des résultats de simulation permettent d'illustrer les méthodes développées. Une application sur un sous-système du véhicule industriel est également réaliséeThis thesis research work focuses on the maintenance operations scheduling and the development of a design methodology for maintenance. The aim is to suggest a customized maintenance service offer for each vehicle and able to adapt to user constraints. In the transport industry, these constraints are defined by a limited number of maintenance opportunities and vehicle unplanned stops with significant financial consequences. This service offer should enable both to improve the vehicle uptime and to reduce the maintenance impact on operating costs. In this framework, the developed maintenance policy ensures, with a given risk probability, maintenance free operating periods for a multi-component system. During these periods, the system should be able to carry out all its assigned missions without maintenance actions and system fault. And the end of each period, the considered policy evaluates if a maintenance action is required to ensure maintenance-free and fault-free operation on the next period with a specified confidence level. When a maintenance action is mandatory, decision criteria considering the maintenance costs and the maintenance efficiency are used to select the operations to be performed. This form of dynamic clustering, called time-driven clustering, integrates both the component reliability models, the system structure and the available monitoring information. In our case, the monitoring information refers to the component state information and information on the component operating conditions. The process flexibility makes possible to make a maintenance decision in using different information levels for system components. The policy parameters, namely the period length and the confidence level value, are optimized based on the total maintenance cost. This cost, evaluated on a finite horizon, is composed of directs costs related to maintenance operations and indirect costs generated by system immobilizations. In order to reach a significant operating costs reduction, the maintenance policy optimization alone is not sufficient. It is essential to have a broader approach to involve the system and its maintenance since the conception. In this context, the developed design methodology suggests to prioritize the components impact on the operating costs. This prioritization is performed thanks to a defined importance factor. Then, multiple design options are evaluated by simulation in priority component. The selected options lead to reduce the operating costs. This work contains simulation results that illustrate the methods mentioned above. Moreover, a heavy vehicle sub-system is used as a test-case