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Roll motion control with a fully active suspension system: High-Level Motion Control and Low-Level Actuator Implementation
(2026) Kanon, Soheb; Li, Yiming
During cornering, vehicle roll motion directly affects lateral load transfer, tire force distribution, and handling consistency. This thesis therefore investigates roll-gradient shaping for a fully active suspension system in simulated cornering maneuvers and driver-in-the-loop tests, with emphasis on how body-level roll objectives can be realized through actuator-level force generation. The proposed method combines a high-level body-motion controller with a low-level hydraulic actuator controller. At the high level, lateral acceleration is estimated from vehicle speed and steering input and used to generate a feedforward roll moment, while proportional-integral (PI) feedback is applied to roll, pitch, and heave states. The resulting generalized force and moment targets are transformed into corner suspension-force commands through a pseudoinverse force-allocation method. At the low level, the required damper forces are converted into continuously controlled damper (CCD) current commands and motor-pump unit (MPU) flow-rate commands using supplier-based lookup tables and mode-switching logic. The controller is implemented in MATLAB/Simulink and evaluated in both IPG CarMaker and the VI-CRT driver-in-the-loop real-time simulator. In CarMaker, the proposed controller tracks prescribed roll-gradient targets and produces suspensionforce distributions that remain consistent with the intended vehicle behavior. The low-level controller also shows satisfactory force-tracking performance, with the main deviations appearing near rapid force reversals. In the VI-CRT simulator, the controller preserves the expected roll characteristics over a wide lateral acceleration range under real-time driving conditions, despite driver input variability and transient steering effects. Overall, the results show that roll-motion control for a fully active suspension system should be evaluated as a connected body-level and actuator-level problem. Highlevel motion objectives and low-level actuator behavior must therefore be considered together when evaluating active suspension concepts.
Design och konstruktion av en 3D-scanner för små objekt
(2026) Damberg, Remus
Detta arbete beskriver konstruktionen av ett skanningssystem för små objekt, utvecklat på uppdrag av Wiretronic AB. Systemet är ämnat att komplettera Wiretronic’s existerande lösningar genom att erbjuda högdetaljerad fotografering av små objekt i storleksordningen 0,5-20mm i syfte att användas för 3D-modellering och träning av AI-modeller. Systemet består av en kvartcirkelformad båge med fyra kameramoduler, ett stegmotordrivet rotationsbord, LED-belysning med manuellt justerbar ljusstyrka och färgtemperatur, samt en Raspberry Pi 4B som beräkningsenhet. Tre avbildningslösningar utvärderades. Raspberry Pi HQ-kameran med teleobjektiv valdes då den optiska förstorningen möjliggjorde effektivt utnyttjande av sensorns upplösning och gav ett tillräckligt skärpedjup för de aktuella objekten. Valet av motorsystem gjordes på teoretisk grund, där stegmotorns positioneringsnoggrannhet utan behov av extern återkoppling bedömdes vara det mest lämpade alternativet. Detta bekräftades vid praktisk testning, där stegmotorn uppvisade mycket god noggrannhet och repeterbarhet. LED-strips med hög färgåtergivning och justerbar färgtemperatur valdes som belysningslösning då dessa gav ett jämnare ljus med färre skuggproblem jämfört med punktformade LED-moduler. Det färdiga systemet fungerar väl och uppfyller de ställda kraven. Identifierade förbättringsmöjligheter inkluderar en mer precis tillverkningsmetod för de mekaniska delarna, då 3D-printing med kommersiell utrustning introducerar geometriska toleransavvikelser som ger en viss gungning i rotationsbordet som blir märkbar först vid inzoomning på objektet. Fast montering av kameramodulerna via deras kretskortsfästen skulle ge en mer robust långsiktig lösning jämfört med det klämbaserade monteringssystemet. Belysningsstyrningen som i nuvarande utförande sker manuellt via potentiometrar skulle med fördel kunna regleras via Raspberry Pi för smidigare kontroll och reproducerbarhet.
Image Processing Framework for Accuracy Measurements in Real-Time Endovascular Simulation
(2026) Franzén, Adam; Swanmark, Linnéa
Training surgeons to navigate catheters and guidewires through blood vessels is challenging, and simulators are increasingly used to practice these procedures safely. However, no standard method currently exists to objectively measure how realistically a simulator reproduces the behavior of real surgical instruments. This thesis presents an image-based framework for the quantitative comparison of physical and simulated catheter configurations, combining camera-based image acquisition, centerline extraction, geometric alignment, and shape comparison metrics. Physical experiments were performed by imaging catheters and guidewires both on flat surfaces and inside a vascular phantom (Physical SIM). The same instrument configurations were then reproduced in the Mentice simulator (VIST), allowing a direct comparison between the physical and virtual setups. The framework was further extended with an automated optimization module that searches for simulator stiffness parameters that best reproduce the observed physical catheter behavior using Bayesian optimization. Validation experiments demonstrated high accuracy in catheter length estimation, achieving a mean absolute error of 0.117 cm and a coefficient of determination exceeding R2 > 0.99. It also remained consistent regardless of the catheter shape. The alignment procedure showed that the extracted centerlines converge to a close geometric correspondence after registration. Optimization experiments further showed that simulator stiffness parameters could be tuned to reproduce physical catheter configurations with high geometric similarity, although discrepancies remained for certain catheter-guidewire combinations. A direct comparison between the physical and virtual environments was additionally limited by fundamental differences in anatomy representation. The results demonstrate that the proposed framework enables quantitative and repeatable evaluation of endovascular simulator realism. Among the evaluated metrics, RMS error and curvature analysis were found to be the most informative: RMS error for localizing spatial deviations along the catheter shaft, and curvature analysis for capturing mechanical differences in instrument bending behavior. The framework provides a foundation for future validation and calibration of catheter mechanics in anatomically realistic simulation environments.
Immersiva upplevelser som väcker intresse -Utveckling av en immersiv installation som lockar unga vuxna till GöteborgsOperan
(2026) Dahlin Griph, Otto; Levinsohn, Douglas
This thesis investigates how immersive installations can be used to spark interest for the Gothenburg Opera among young adults aged 18–35. The study was conducted using a user-centered and iterative design process that included a preliminary study, user interviews, concept generation, protype development, and user testing. Qualitative methods like affinity diagrams, observations, and group interviews, were used to identify key factors influencing engagement and immersion. The findings indicate that social interaction is the most significant factor contributing to the impact of the experience, while emotional engagement and coherent multisensory design also play important roles. Two final prototypes, a narrative driven puzzle installation and a social competitive shadow play experience demonstrate that immersive installations have the potential to increase young adults’ interest in opera and spark curiosity about the Gothenburg Opera´s activities. However, this potential depends on a clear connection between the installation and the opera´s content, as well as an accessible and intuitive user experience.
Micromechanical modeling of fracture in high-pressure die cast aluminum
(2026) Abel, William; Kullberg, Valdemar
High-pressure die cast aluminum is being incorporated into the production of electric vehicles in order to increase vehicle efficiency and reduce manufacturing costs. The process is known as Mega Casting and can produce large scale components with complex geometry in one process, drastically reducing the amount of welds and joints. Due to the process, the aluminum components possess a complex microstructure with different phases and porosity, which makes the mechanical properties difficult to predict. Today, there is a lack of Finite Element (FE) and material models that can capture these microstructural defects on a component scale. Throughout the project, a method for generation of three-phase microstructure models based on Computer Tomography (CT) scanning and Scanning Electron Microscope (SEM) images is developed. Numerical studies on mesh design, time integration and boundary conditions are performed with the intention to optimize computational costs while maintaining accuracy. Furthermore, the variation in mechanical properties depending on morphology is studied by simulating a range of different microstructures subjected to different load cases. The results show that it is possible to generate three-phase microstructures that represent the eutectic silicon region in HPDC-aluminum components. The choices of the numerical model and modeling have impact on computational efficiency and accuracy. Furthermore, it is possible to vary the internal morphology in the model in order to obtain mechanical response data for a wide range of microstructures.