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Syftet med denna avhandling var att uppskatta livslängden och tillförlitligheten för det elektromekaniska linjära ställdonet genom att använda metoder för sannolikhet och statistik, med fokus på att fastställa svagare områden som kan förbättras för att inkludera dessa förbättringar i kommande generation. Bedömningen gjordes kvantitativt och kvalitativt. FMEA valdes för den kvalitativa analysen. För den kvantitativa analysen bedömdes Weibull-distribution vara den mest lämpliga för att skatta komponenternas felfrekvens. För detta valdes form- och skalparametrar enligt B. Bertsche. [1] Övergripande systemtillförlitlighet uppskattades utifrån den Boolean-teorin, där en känslighetsanalys utfördes med utgång från systemet fortsatta funktion. Det inkluderade utvärdering av komponenternas relativa betydelse för den övergripande tillförlitligheten, och att utföra känslighetsanalys med avseende på systemkomponenternas fördelningsparametrar. Baserat på den information som erhållits från kvalitativ och kvantitativ analys, erhölls underhållsaktiviteter för det elektromekaniska ställdonet under servicetiden. För att föreslå lämpliga tillförlitlighetstester var det nödvändigt att först fastställa storlek och testlängd för kommande prov. Flera testmetoder och respektive provstorleksuppskattning och urvalstester för testlängd studerades. Resultatet från FMEA ser totalt sett lovande ut. Det finns en möjlighet att några mindre fel uppstår i smörj-, kyl- och övervakningssystemet, som kan tas om hand genom att följa föreslagna underhållsaktiviteter. Ingen komponent sticker särskilt ut i tillförlitlighetsanalysen, med tanke på att säkerhetsfaktorerna för växlar överskrider minimigränsen och axlar som är konstruerade för oändlig livslängd. Individuellt verkar de utvalda lagren inte påverka det övergripande systemets tillförlitlighet. Men eftersom komponenterna anses vara i serie verkar den kombinerade tillförlitligheten hos lagren dominera hela systemets tillförlitlighet. Eftersom de tre fallstudierna genomförs för att förstå systemets beteende när det gäller tillförlitlighet, gäller ovanstående resultat för de två första fallstudierna där redskapen var säkra. I fallstudie tre påverkades systemets tillförlitlighet av både växlar och lager. Känslighetsanalysen följde samma mönster som det ses i tillförlitlighetsanalys. För fallstudie 1 och 2 - lager är signifikanta och i fallstudie 3 - rack och kugghjul 2 var mer signifikanta än lager. För tillförlitlighetsprovning har censureringsmetoder av Typ 1 och Typ 2 visat sig vara lämpliga. För uppskattning av testprov erhölls att generaliseringen av felmetoden med hjälp av Larsens nomogram var idealisk för tidiga förutsägelser. / The purpose of this thesis was to estimate the life and reliability of an electromechanical linear actuator by using methods of probability and statistics. It was essential to determine weaker areas subject to improvement and include these improvements in the design to next generations. The assessment was carried out quantitatively and qualitatively. Failure mode effects analysis was the method opted for the qualitative analysis. For the quantitative analysis, Weibull distribution was found to be the most suitable to present the failure rate of components. For the same, the shape and scale parameters were selected as suggested by B. Bertsche. [1] Overall system reliability was estimated on the basis of Boolean theory. Sensitivity analysis was carried out by using survival signature method. It included evaluating the relative importance of the components with respect to overall reliability and carrying out sensitivity analysis with respect to the distribution parameters of the system components. Based on the information obtained from qualitative and quantitative analysis, maintenance activities were derived for the electro-mechanical actuator for the period of service time. To suggest the suitable reliability tests, it was necessary to first determine the test sample size and test duration. Several test methods and respective sample size estimation and test duration selection methods were studied. In performed failure mode and effects analysis, overall the system looks promising. There is a possibility of some minor possible failures to occur in lubrication, cooling and monitoring system, which could be taken care of by following suggested maintenance activities. No component in particular stand out in the reliability analysis, given that the safety factors of gears exceed the minimum limit and shafts designed for infinite lifetime. Individually the selected bearings seem to not affect the overall system’s reliability. However, since the components are considered to be in series, the combined reliability of the bearings seem to dominate the whole system’s reliability. As the three case studies are conducted to understand the system’s behaviour in terms of reliability, above result is applicable for the first two case studies where gears are found to be safe. In case of case study three, the system’s reliability is found to be affected by both gears and bearings. The results of sensitivity analysis followed the same pattern as reliability analysis. For case study 1 and 2 - bearings were significant and in case of case study 3 - rack and gear 2 were more significant than bearings. For reliability testing, Type 1 and Type 2 censoring methods both are found to be suitable. For test sample estimation, generalisation of failures method using Larsen’s nomogram was found ideal for early predictions.

Over the past years, bicycles started to gain popularity and more people are now using it as amean of transportation. Nowadays, sustainability trends promote cycling as one of the greenestsolutions for the future in mobility. With this rising demand in the number of bicycle trips, there isa need to design adequate infrastructure fitted to the behavior of cyclists and their traffic patterns.Even though there is plenty information regarding car driving behavior, there is still a lack ofunderstanding in how cyclists behave. Consequently, the behavior of cyclists is often modelled byadjusting parameters from models originally designed for other types of users (e.g. car-followingmodels).The purpose of this degree project is to increase the understanding of the behavior of cyclists byinvestigating the extent to what car-following models can be used to simulate bicycle traffic andwhat effects relevant parameters have on the behavior of simulated cyclists and specific trafficcharacteristics. The main method is microscopic traffic simulation, through the simulation programVissim, of bicycle traffic flow on a two-way separated cycle path in Stockholm, withoutdisturbances from pedestrian and car traffic. In addition, a sensitivity analysis is presented, withthe support of the Elementary Effects method, of behavioral parameters of following, overtaking,lateral position, and the longitudinal gradient of the cycle path, and their effects on speed, lateralposition, and time headway.The sensitivity analysis showed that the minimum lateral distance between cyclists is a keyparameter to model following and overtaking behavior, while the gradient was found to be animportant factor that has a great impact on the bicycle traffic performance. Overall, the resultsindicated that the Vissim implementation of the Wiedemann car-following model is able toreproduce the speed and time headway on flat cycle paths with high flows, with goodapproximation to reality. However, the model failed to represent the effect of gradient, and thelateral position of cyclists could only be achieved with a low level of detail and accuracy.The understanding of the behavior of cyclists is crucial for the design and planning of infrastructurededicated to bicycles, so transport planners can consider the needs of cyclists. This projectcontributes to establish a baseline for bicycle traffic modelling and its adaptation of car-followingmodels to simulate cyclists and bicycle traffic. The awareness of these adaptations will help topromote cycling in order to achieve a more sustainable transport system

Det finns en ökande efterfrågan på förnybar elproduktion och effektiva lösningar att kombinera med denna. Ett flertal tidigare arbeten har undersökt energilagringssystem (ESS) och dess lönsamhet i olika tillämpningar. Det råder en osäkerhet kring lönsamheten hos ESS för ökad självkonsumtion i Sverige. Detta arbete undersöker lönsamheten hos batterilagringssystem (BESS) som används i syftet att öka självkonsumtionen för aktörer med solceller i den svenska bostadssektorn. En modell konstruerades baserat på Levelized Cost of Storage (LCOS), och indata till modellen varierades för olika scenarier. Resultaten visade att BESS kostnader i dagsläget är för höga, med LCOS mellan 1,68 kr/kWh och 3,56 kr/kWh beroende på aktör och indata. För lönsamhet krävs reduktion av LCOS mellan 55% och 85%. Vidare undersöker arbetet vilka variabler som har störst påverkan på BESS lönsamhet. En känslighetsanalys genomfördes, där CAPEX, antalet battericykler per år, WACC och skattereduktioner vid elhandel identifierades som viktiga variabler. Arbetet visade att det antagligen krävs en kombination av högre elpriser och reducerade investeringskostnader för att motivera en investering i BESS. Utöver ökad självkonsumtion behövs ytterligare värden för att motivera en investering i BESS inom en snar framtid. / There is a growing demand for renewable power generation and efficient solutions to combine with renewables. Previous works have explored energy storage systems (ESS) and their profitability in various applications. There is an uncertainty about the profitability of ESS for increased self-consumption in Sweden. This thesis explores the profitability of battery energy storage systems (BESS) used for increased self-consumption for stakeholders with solar photovoltaics in the Swedish residential sector. A model based on levelized cost of storage (LCOS) was constructed, and varying input values were used for different scenarios. The results showed that the current cost of BESS is too high, with LCOS ranging between 1,68 SEK/kWh and 3,56 SEK/kWh depending on the stakeholder as well as input data. For profitability, a reduction of LCOS between 55% and 85% is needed. Furthermore, this thesis explores which variables have the greatest effect on a BESS’s profitability. A sensitivity analysis was conducted, where CAPEX, the number of battery cycles per year, WACC and tax reductions linked to electricity trading were identified as important variables. This thesis concluded that higher electricity prices in combination with reduced investment costs is needed to justify an investment in BESS. Besides increased self-consumption, other values are needed to justify an investment in a BESS in the near future.

<p>This thesis proposes a new analytical self-adjoint sensitivity analysis to calculate the Jacobian of the <em>S</em>-parameters for metallic shape parameters. This method is independent of the full-wave numerical analysis and the respective system matrix. The theory works for both volumetric and infinitesimally thin metallic shapes. It exploits the computational efficiency of the self-adjoint sensitivity analysis (SASA) approach where only one EM simulation suffices to obtain both the responses and their gradients in the designable parameter space.</p> <p>There are three major advantages to this development: (1) the Jacobian computation for metallic structures is completely analytical and there is no approximation involved in the sensitivity analysis of shape parameters; (2) the implementation is straightforward and in the form of a post-processing algorithm operating on the exported field solutions on the surface or around the edge of the metallic structure; and (3) it provides the possibility for exact sensitivity analysis with all electromagnetic high-frequency simulators whose system matrices are not available to export or are not differentiable with respect to shape parameters, e.g., simulators based on the FDTD method and the MoM.</p> <p>The method was verified in a number of examples using a commercial finite-element solver. The agreement between the results calculated with the proposed method and the reference self-adjoint sensitivity curves provided with the simulator are very promising.</p> <p>Suggestions for future work are provided.</p> / Master of Applied Science (MASc)