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Senast publicerade

Development of a small-scale electric vehicle for evaluation of torque vectoring and MPC path tracking
(2026) Bäckborn, Alfred; Eriksson, Ludvig; Harb, Kristina; Nasir, Houd; Ohlin, Gustav; Solibi, Johannes
In this thesis, a small-scale electrical vehicle with independently driven rear wheels is developed to implement and test torque vectoring and MPC using microcontrollers. The project investigated how torque distribution affects stability, maneuverability and trajectory tracking during representative driving maneuvers. A scale RC car chassis was purchased and equipped with custom mechanical components, electric motors, electronic speed controllers, battery, microcontrollers and an internal measuring unit to form a closed-loop control platform. The control system combined MPC using the TinyMPC library for path tracking with a PID-controller based torque vectoring strategy to influence yaw behavior. The system was evaluated through simulations and practical testing, where vehicle trajectories were extracted from video recordings using image processing. The results showed that torque vectoring generated noticeable but moderate handling improvements. However, performance was limited by hardware constraints, simplified modeling, incomplete PID-controller tuning, limited torque authority and sensor limitations. Nevertheless, the project demonstrates that torque vectoring can improve controllability on a low-cost small-scale electric vehicle platform, as well as validating that MPC can be implemented on limited hardware, such as microcontrollers. It also shows that further development is required for more robust and quantitatively reliable results. Recommended improvements include systematic controller tuning, improved state estimation, onboard data logging, slip-angle control implementation, PWM-to-torque mapping, and more capable actuators.
Development and testing of a steer-by-wire platform, using a four-wheel steering control system
(2026) Frick, Anders; Omanovic, Amar; Isaksson, Valter
The rapid electrification of the automotive industry has created new opportunities for integrated vehicle control, including steer-by-wire and four-wheel steering systems. Small-scale prototypes can provide a cost-effective platform for developing and evaluating control strategies aimed at improving vehicle stability and maneuverability. The purpose of this project was to design, assemble, and evaluate a small-scale electric vehicle prototype equipped with electronically actuated four-wheel steering to investigate vehicle dynamics and path-following control. A modular chassis was developed using 3D-printed components, integrating two DC propulsion motors, two steering servos, and a Teensy 4.1 microcontroller. A Proportional–Integral (PI) control strategy was implemented in simulation to regulate wheel speed and steering angle. Due to hardware-related and time constraints, the physical implementation was limited to individual PI-based wheel speed regulation. Testing demonstrated that the PI controllers successfully maintained the target average wheel speed of 80 RPM with a small mean error. However, the physical tests revealed that instantaneous speed variations, amplified by sensor noise and mechanical tolerances in the 3D-printed assemblies, introduced lateral instability and deviations from a straight path. Ultimately the project delivered a simulation using a PI control strategy and a hardware platform for further four-wheel steering research.
Powder-Logistics Concept for Future LPBF High-Volume Shop Developing a scalable powder-logistics concept for serial LPBF production
(2026) Larsson, Pontus; Mellbin, Elise
Following the increasing use of additive manufacturing in aerospace production, Laser Powder Bed Fusion has become an important technology for producing complex and lightweight metal components. However, scaling LPBF from a low-volume demonstration environment to high- volume serial production creates new requirements for powder-logistics. Metal powder must be handled safely, traceably and efficiently, while risks related to manual handling, contamination, ergonomics and tied-up capital need to be controlled. This study investigates a company within the aerospace industry that is preparing a future high- volume LPBF production facility. The current powder-logistics setup is mainly designed for low-volume development and learning and is therefore not suitable for the expected increase in production volume, material movements and parallel powder flows. Therefore, this study aims to support the company by developing and evaluating a powder-logistics concept that enables safe, traceable, cost-efficient and scalable operations. Through observations, interviews, internal data, workshops, Material Flow Mapping and Systematic Layout Planning, several limiting factors were identified and analyzed. These included manual handling, unclear storage logic, high handling frequency, traceability requirements, operational risks and the need for future scalability. To address these factors, a final powder-logistics concept is proposed. The concept includes a structured cell-based layout, larger powder units, defined storage and filling zones, improved identification systems, lifting support and is automation-ready. By implementing the proposed concept, the company can reduce handling complexity, improve traceability and operator safety, and create a scalable structure that can be multiplied as production volume increases.
Begränsningar i gravitationslinsmodellering av avlägsna galaxer
(2026) Björl, Elias; Grandin, Marcus; Senges Jaretun, Anton
In this thesis, we investigated the limitations of gravitational lens modeling of distant galaxies using the ALMA telescope. The aim of our study was to improve the understanding of galaxy evolution, which in turn could provide deeper insight into the early universe. The simulations were carried out in CASA (Common Astronomy Software Applications), where the lens modeling code was written in Python using the PyAutolens package, and both lensed and unlensed galaxies were modeled. The purpose was to identify which parameters were most suitable depending on different input galaxy models and observational parameters. Furthermore, the goal was to use nearby galaxies as input data in order to compare and evaluate the lens model’s ability to reconstruct these better-known galaxies. The simulations showed that gravitational lens modeling in CASA can generally reconstruct source planes and velocity dispersions well, especially for galaxies that are centered and have a low inclination angle. Despite some loss of detailed information, the thesis shows that gravitational lensing is an effective method for reconstructing and studying distant galaxies that would otherwise be difficult to observe.
Avståndsbestämning till AGB-stjärnor genom parallaxmätning
(2026) Andersson, Karl; Johansson, Benjamin; Ovik, Otto; Wetterberg, Philip
In this thesis distance to nearby AGB-stars – stars in the end of their lifecycle with a mass of 0.8–8.0M⊙ – were calculated using parallax. The characteristical dynamic of these stars creates intensity fluctuations which together with their giant size makes measuring the coordinates of the stars a non trivial task. Different methods for estimating the centre point of the stars were evaluated. To obtain a good resolution of the stars that were examined – R Doradus, R Leonis, W Hydrae, Mira A and B – several observations, separated in time, from the ALMA-telescope were used. Estimates for the parallax and proper motion – the stars apparent movement on the celestial sphere, excluding parallax – were extracted by fitting the stars celestial movement for the different methods. To achieve a better precision the resampling method jackknife were used. The methods that gave the best result were gaussian fit and different variants of half max intensity fit. The gaussian fit gave the distances: 47 +4 −3 pc for R Doradus, 134 +71 −35 pc for R Leonis, 106 +29 −19 pc for W Hydrae, 121 +34 −23 pc for Mira A and 126 +55 −31 pc for Mira B. The calculated astrometric values agrees with values from the space telescopes Hipparcos and Gaia, however, the calculated values for the proper motion have a better precision in comparison. Further studies of the binary star Mira should take its orbit into account.