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Senast publicerade

Estimering av normalkrafter på däck i en Formula Student-bil - Estimation of Tyre Normal Forces in a Formula Student Car
(2026) Nielsen, Olle; Jonsson, Albin; Örnberg, Carl-Johan; Pankovski, Damjan; Haidari, Dania; Cederfjord, Erik
En korrekt estimering av vertikala normalkrafter på ett fordons hjul är avgörande för optimal vridmomentfördelning och maximalt väggrepp i en fyrhjulsdriven Formula Student-bil. Den nuvarande modellen som används inom Chalmers Formula Student (CFS) har inte tidigare validerats mot referensdata eller jämförts med alternativa modellansatser. Syftet med detta kandidatarbete är att bedöma noggrannheten hos den nuvarande modellen för normalkraftsestimering vid olika körfall, samt att jämföra om alternativa fysikbaserade modeller kan ge förbättrade resultat. Arbetet ger CFS underlag för val av estimeringsmodell i framtida utveckling av bilen. Arbetet omfattar implementering av den nuvarande modellen, en helfordonsmodell som tar hänsyn till bland annat fordonets karossrörelser och en fjädermodell som bygger på fjädringssystemets vertikala rörelser. Modellerna har utvärderats genom simulerade körfall som omfattar bland annat en Endurance-bana samt olika manövrer på en raksträcka och en cirkelbana. Resultaten jämförs med referensdata från IPG CarMaker och analyseras utifrån felmått. Studien visar att mer avancerade modellstrukturer inte nödvändigtvis förbättrar noggrannheten vid dynamiska manövrer. Accurate estimation of vertical tyre normal forces is essential for optimal torque distribution and maximum grip in a four-wheel-drive Formula Student vehicle. The model currently used within Chalmers Formula Student (CFS) has not previously been validated against reference data, nor compared to alternative modelling approaches. The purpose of this bachelor thesis is to assess the accuracy of the current model for normal force estimation across different driving scenarios, and to compare whether alternative physics-based models can provide improved results. The thesis provides CFS with a basis for selecting an estimation model in the future development of the vehicle. The work includes implementation of the current model used by CFS, a full-vehicle model that accounts for body motions among other effects, and a suspension model based on the vertical motions of the suspension system. The models were evaluated through simulated driving scenarios including an Endurance track as well as various manoeuvres on a straight road and a circular track. The results are compared with reference data from IPG CarMaker and analysed using error metrics. The study shows that more advanced model structures do not necessarily improve accuracy during dynamic manoeuvres.
Produktions- och energilagringsdimensionering av ett 100% förnybart elsystem i SE3 - Dimensioning of Power Production and Energy Storage for a 100% Renewable Power Grid in SE3
(2026) Sundbom, Hugo; Savic, Stefan; Gredevik, Linn; Moreland, Daniel; Johansson, Gustav
The study has explored from both an economical and environmental perspective, how a 100% renewable energy system in SE3 can be designed. On the production side, the focus is placed primarily on the combination of wind and solar power together with the existing hydro power capacity. Energy storage in the form of battery and hydrogen storage is assumed to complement the electricity production, and different combinations of these technologies are simulated. In addition, an analysis was conducted regarding the role nuclear power could play in a transition towards a renewable energy system. The results show a clear trade-off between cost and emission minimization. The most economically favourable configurations are heavily dominated by wind power, with installed capacities ranging between 87.5 and 91.9GW, and rely almost exclusively on battery storage. The least expensive solution corresponds to an investment cost of approximately SEK 2010 billion, with a climate impact of around 150 Mtons CO2e. The configurations that achieve the lowest climate impact reach emissions of approximately 70.9 Mtons CO2e, but at an estimated cost of SEK 3440 billion, and require a larger share of hydrogen storage. A sensitivity analysis shows that reductions in storage technology costs affect the overall cost levels, but not the system configurations when emissions are minimized. When the cost of both storage technologies is halved, the investment cost decreases to SEK 1680 billion. The analysis including continued nuclear power as a complement reveals a clear difference in which configurations perform the best, from both cost- and emissions minimizing perspectives. The lowest achievable cost decreases to SEK 726 billion, while the lowest achievable emissions decrease to 27.0 Mtons CO2e. This indicates that retaining nuclear power generation may provide value if a longer transition from the current electricity system toward a fully renewable system is desired. It is therefore technically possible to supply SE3 with 100% renewable electricity, but the choice of system configuration depends on the objectives and constraints that are imposed. Studien har undersökt, ur ett ekonomiskt och ett miljömässigt perspektiv, hur ett 100% förnybart elsystem i SE3 kan dimensioneras. Produktionsmässigt läggs fokus på sol- och vindkraftsfördelningar i kombination med den befintliga vattenkraften. Energilagring i form av batteri- och vätgaslagring räknas agera som komplement till produktionen och olika kombinationer av dessa simuleras. Utöver detta har en analys för vilken roll kärnkraft kan spela i en övergång till ett förnybart elsystem genomförts. Resultaten visar en tydlig målkonflikt mellan kostnadsminimering och utsläppsminimering. De ekonomiskt mest fördelaktiga konfigurationerna domineras kraftigt av vindkraft, med installerade effekter mellan 87,5 och 91,9GW, och förlitar sig nästan uteslutande på batterilagring. Den billigaste lösningen uppgår till en investeringskostnad på cirka 2010 miljarder kr med ett klimatavtryck på cirka 150 Mton CO2e. De konfigurationer som ger lägst klimatpåverkan uppnår utsläpp kring 70,9 Mton CO2e men till en beräknad kostnad på 3440 miljarder kr, och kräver en större andel vätgaslagring. En känslighetsanalys visar att prisreduktioner på lagringstekniken påverkar kostnadsbilden men reducerar inte konfigurationernas utsläpp. Vid halvering av priset på båda lagringsteknikerna sjunker investeringskostnaden till 1680 miljarder kr. Analysen med fortsatt kärnkraft som komplement ger en tydlig skillnad i vilka konfigurationer som presterar bäst, både ur kostnads och emissionsminimerande perspektiv. Den lägsta möjliga kostnaden sjunker till 726 miljarder kr och det lägsta möjliga utsläppet till 27,0 Mton CO2e. Detta visar på att det finns ett värde i att ha kvar kärnkraftproduktionen ifall en längre övergång från det nuvarande elsystemet till ett förnybart söks. Det är därför tekniskt möjligt att förse SE3 med 100% förnybar elproduktion, men valet av systemkonfigurationen beror på vilka mål och begränsningar som sätts.
Dynamiskt LED-system för växter - Dynamic LED Control System for Agriculture
(2026) Gybrant, Anton; Vigeliusson, Elliot; Amberg, Alexander; Thorsell, Theo; Peterson, Atle
This thesis focuses on the design and construction of a LED based lighting system for agricultural applications. The purpose is to develop a system that employs PWM dimming to adjust the spectral composition and intensity of the emitted light by changing the duty cycle with a microprocessor. This enables the spectral output of the lighting system to be controlled to meet the requirements of different plants. The goal is to achieve higher efficiency than current HPS-based lighting systems used in agriculture. The project encompasses the design and testing of a PCB used to drive and control a LED PCB. The prototype was constructed to allow both manual control of individual channels and automatic regulation via a PI controller that utilizes real-time input from an external light sensor. The results show that the efficacy of the system is nearly doubled that of a HPS based lighting system. The lighting system was able to produce a PPFD of 235 μmol/(m2s) with an intended light mix at the ratio 20:60:20 between blue, red and far-red light. At this PPFD, the blue and far-red light intensities could be increased by more than 100%, allowing substantial flexibility in spectral composition. With this light mix, the system had a calculated efficacy of 3.43 PPF/W, with up to 61% of the input power being translated into photosynthetically active light. Disregarding light mix, the maximum achievable PPFD of the system is 378 μmol/(m2s). Incorrect dimensioning of some LED driver components and suspected electromagnetic interference causes lower than intended ON current from the LED drivers. This results in the spectral output being less adjustable than intended. While the system can compensate for ambient light, the spectral sensor used is only capable of measuring relative light intensity and lacks the ability to measure absolute photon flux density. The control system is highly sensitive to positional changes of the spectral sensor. A calibration method was implemented to dynamically set the target based on the current sensor position. Electrical protection measures were successfully implemented into the design.
Analysis of Dual-Motor Drivetrain Architectures with Torque Distribution - Energy Consumption Evaluation for Electric Articulated Haulers
(2026) Zhao, Junyu
The electrification of heavy-duty articulated vehicles increases the demand for efficient and flexible drivetrain systems. Focusing on the electric articulated hauler platform exemplified by the Volvo A30, this thesis sets out to explore how different dual-motor drivetrain configurations impact the vehicle’s energy consumption patterns. To conduct this investigation, three distinct drivetrain architectures were assessed: a fully coupled baseline design, a partially coupled configuration featuring asymmetric motor sizing with adjusted gear ratios, and a simplified fully decoupled architecture. A unified forward energy flow simulation framework is developed for systematic comparison under representative heavy-duty operating conditions. The findings of the research highlight that the effectiveness of torque distribution is closely tied to two key factors: operating condition and the drivetrain configuration. Among the investigated configurations, the partially coupled architecture consistently achieves lower energy consumption across all evaluated scenarios. The results suggest that the combination of asymmetric motor sizing, modified gear ratios, and torque distribution strategy can improve drivetrain operating behavior and reduce overall energy consumption under certain load conditions. In summary, this study provides clear evidence that making moderate system-level adjustments to existing dual-motor drivetrain architectures can unlock potential for improving the energy efficiency of heavy-duty electric articulated vehicles.
Feasibility of Deep Neural Network Surrogate Models for Simulations of High Voltage Equipment Design
(2026) Albers, Josefin; Wolke, Felix
With the recent advances in Machine Learning, there is a natural interest in investigating potential application areas where it could contribute to more efficient solutions. This thesis investigates the feasibility of the Deep Neural Network (DNN) approach implemented in the COMSOL Multiphysics software, for simulations of high voltage components by comparing respective results with traditional finite element solutions. The project encompasses a best practice study for DNN model parameter optimization, by considering electrostatic problems for two cases, utilizing different representative geometries. In addition, the result from one of the study cases is further applied for establishing best practices for streamer breakdown detection problems. The DNN approach was found feasible for applications with relatively low-complexity geometries and simple physics. However, there are areas of study where it did not outperform traditional finite element solutions. Thus, when simulating complex geometries or physics with DNN, the improvement in efficiency compared to using finite element methods diminishes. From the obtained results, it is apparent that further studies in the area are necessary to explore advantages and limitations of the method.