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Machinability of 100Cr6 bearing steels
(2024) Andersson, Daniel; Aronsson, Martin; Chalmers tekniska högskola / Institutionen för industri- och materialvetenskap; Chalmers University of Technology / Department of Industrial and Materials Science; Malakizadi, Amir; Salame, Charlie; Boing, Denis; Vikenadler, Elias; M'saoubi, Rachid
The aim of this master’s thesis is to investigate the influence of batch-to-batch microstructural variations on tool wear evolution when machining 100Cr6 bearing steel using coated carbides. Furthermore, a secondary aim is to investigate the performance of coated tool grades coated with different combinations of titanium carbonitride and alumina when used to machine 100Cr6. Tool life tests under constant spiral cutting lengths as well as orthogonal cutting tests with in-situ data acquisition were performed at various cutting conditions to investigate the machinability. The tool wear results were then correlated with the material and tool characteristics examined using various methods including light optical microscopy, stereo optical microscopy, hardness testing, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. A notable difference in tool wear evolution was found when machining the steel batches. The differences in microstructural properties such as the pearlite lamellar spacing and the measured hardness values were less pronounced, and thus they cannot solely explain the difference observed in tool performance when machining different batches of steels. However, the detailed material analysis showed chemical differences between the batches in terms of calcium and sulphur content, with corresponding differences in the non-metallic inclusion (NMI) content and type. Differences in tool wear behaviour when machining the steel batches showed a clearer correlation with the amount and type of these NMIs. Higher flank wear was observed when machining the steel batch with lower calcium content, while higher crater wear evolutions occurred when machining the cleanest batch with considerably lower sulphur content. Regarding the tool grades and their performance, the one closest to the current commercial grades (with a nearly equal thickness of alumina and titanium carbonitride coating layers) suffered the lowest average wear, whilst the grades having single-layer coatings of either alumina or titanium carbonitride performed significantly worse.
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Samarbetet mellan Tullverket och kommersiell sjöfart med målet att förhindra illegal införsel av narkotika
(2024) Kärnbratt, Andreas; Ström, Felix; Chalmers tekniska högskola / Institutionen för mekanik och maritima vetenskaper; Chalmers University of Technology / Department of Mechanics and Maritime Sciences; Larsson, Martin; Severin, Robert
Narkotikasmuggling är ett globalt problem vilket har ökat i Sverige det senaste decenniet. Tullverket är den svenska myndighet som ansvarar för att kontrollera varuflödet in och ut ur Sverige. Samarbetet mellan Tullverket och den kommersiella sjöfarten är en vital del i förhindrandet av narkotikasmuggling. Tullverket och aktörer inom den kommersiella sjöfarten har skapat gemensamma målsättningar för att bekämpa tullbrottslighet och förhindra att näringslivet utnyttjas av kriminella nätverk. Syftet med rapporten är att utreda samarbetet mellan svenska Tullverket och kommersiell sjöfart för att minska narkotikasmugglingen genom hamnar i Sverige. Rapporten kommer att behandla problematiken i samarbetet mellan myndigheter och kommersiell verksamhet, samt ytterligare vilka faktorer som påverkar samarbetet positivt mellan nämnda parter. Vidare behandlar studien följande frågeställningar: • Hur ser det aktuella samarbetet ut mellan Tullverket och kommersiell sjöfart för att bekämpa smuggling av narkotika genom svenska hamnar? • Vilka faktorer kan identifieras som framgångsfaktorer i samarbetet mellan Tullverket och den kommersiella sjöfarten i Sverige? För att besvara studiens syfte och forskningsfrågor genomfördes en kvalitativ studie med semistrukturerade intervjuer. Respondenterna vilka intervjuades bestod av anställda hos Tullverket samt representanter från den kommersiella sjöfarten. Resultatet visar att samarbetet mellan Tullverket och den kommersiella sjöfarten idag främjas till stor del av ett samarbete i avtalad form. I samarbetet anses framgångsfaktorerna bestå av personlig kontakt, tullutbildningar och ett antal lättnader för den kommersiella verksamheten, dessa gynnar såväl Tullverket som de kommersiella aktörerna. Utöver de positiva delar vilka avtalet medför, framgår det av resultatet att samarbetet även ställs inför ett antal utmaningar, såsom korruption och tystnadskultur. Studien har avgränsats till myndigheten Tullverket samt till rederier inom kommersiell sjöfart, för att möjliggöra en fördjupning inom området. Vidare har studien avgränsats genom sin fokusering på sjöfarten som metod för smuggling, vilket innebär att
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Optimizing product configuration processes
(2024) Udén, Adam; Mannerstråle, Victor; Chalmers tekniska högskola / Institutionen för industri- och materialvetenskap; Chalmers University of Technology / Department of Industrial and Materials Science; Bergsjö , Dag; Bergsjö, Dag
This thesis investigates the implementation of a new product configuration process and the key factors that determine the success of the new process. Through data collection methods and several analyses of the collected data, five key aspects were identified: Standardization of formats and processes, Streamlining data flow, Enhanced version control, Minimizing human errors, and Adapting to systems and external parties. Comprehensive analyses revealed that standardization and streamlining significantly improve efficiency and reduce errors. The practical implementation of a new IT system within the configuration process at the collaborative company Polestar underscored the importance of establishing clear templates and workflows to enhance consistency and ease of use. Streamlining data flow through automated notifications and system integration minimized delays and gaps, increasing visibility and accountability. Enhanced version control systems facilitated accurate tracking of document revisions, promoting transparency and compliance for external and internal audits and regulations. Minimizing human errors involved automating repetitive tasks and implementing validation checks, improving accuracy and efficiency. Adapting to systems and external parties emphasized the importance of collaboration and alignment to ensure seamless data exchange. These findings align with the Lean methodology, which emphasizes continuous improvement and customer-centricity. Analyses conducted in this project provided a profound understanding of data flow dynamics, overcoming challenges associated with stakeholder comprehension. Initial visual mapping clarified data flow, while subsequent process and information models offered nuanced insights into process dynamics and data integration, empowering stakeholders to identify areas for improvement. This clarity facilitated collaborative efforts, evident during the implementation of the new IT system with Polestar. Moreover, the analysis of the new IT system underscored the significance of "Minimizing Human Errors" and "Enhanced Version Control" in mitigating information loss. Automated change logs and dedicated SharePoint folders streamlined document tracking, reducing errors and enhancing efficiency and compliance with regulations. Prioritizing these factors led to a smoother configuration process, minimizing information loss and enhancing user accountability. Further research is recommended to validate these findings across diverse companies beyond Polestar, confirming the effectiveness of the identified framework in various industries. Additionally, refining the developed IT system to address bugs and expand its coverage within the configuration process could enhance its performance. Exploring the optimal configuration process structure, whether a single supersystem or multiple subsystems, would be valuable for future investigation, offering insights into associated benefits and challenges
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The Connection Between the Resource Models and Process Structure
(2024) Christiansen, Jacob; Gaal, Péter; Chalmers tekniska högskola / Institutionen för industri- och materialvetenskap; Chalmers University of Technology / Department of Industrial and Materials Science; Bergsjö, Dag; Erixon , Liselott
In modern manufacturing, seamlessly integrating resources with the process structure is crucial for efficiency and product quality. This study investigates the value and challenges of connecting resource 3D models with the process structure and the consequences if the connection does not happen. Research quality is ensured by adopting the Design Research Methodology. The study conducted a thorough literature study to give a substantial theoretical background. Provided with the gathered information, semi-structured interviews were conducted, providing interviewees the flexibility to express their views on their terms and get deeper into subjects relevant to them regarding the project. Additionally, observations were conducted to understand how employees currently work in the system. The findings unfold an opportunity for improvement related to how the case company delivers instructions on how to build upcoming cars to the factory. In the current delivery of instructions and process structures, resource 3D models are not linked, often resulting in only the displaying of resource item numbers or empty fields. This challenge often results in significant time savings once resolved. Connecting resources not only enhances visualization and transparency but also fosters collaboration, breaking down silos within the organization. The project investigates two alternative ways of working for the future and looks into a possible interim solution. Since there are alternative solutions the project concludes with a recommendation for how to tackle this challenge most effectively in the future. A successful connection would gather all data related to the assembly operation in the same place, diminishing miscommunications and enhancing cross-functional collaboration. Consequently, significant time would be saved that otherwise would be spent on searching and contacting other departments to get an understanding of what is included in the assembly operation.
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Synthetic Data generation for Object Recognition and Pose Estimation
(2024) Zhang, Desheng; Kong, Xiangbo; Chalmers tekniska högskola / Institutionen för industri- och materialvetenskap; Chalmers University of Technology / Department of Industrial and Materials Science; Johansson, Björn; Wang, Hao; Marti, Silvan
The automotive industry is looking for methods to promote a flexible robotic assembly on objects which are difficult for conventional robotic systems based on preprogramming. Specifically, it is difficult to automate wire harness assembly onto vehicles due to the limitation of current robotic assembly on pre-programed tasks and the deformability of wire harnesses. In order to achieve flexible wire harness assembly a well developed vision system. It is necessary for robots to perceive the spatial information of wire harnesses and adapt their actions to handle the objects. Computer vision techniques such as object recognition and pose estimation have been widely adopted in robotics to promote the perception capabilities of robots and the significant advancement in deep learning has remarkably promoted the research in computer vision. However, a vast amount of time and human effort are needed to collect and annotate the datasets for training deep learning models. In recent years, researchers apply synthetic dataset in computer vision tasks, which requires less human effort and promises good annotation quality. In this thesis, the synthetic datasets of connectors are created by using a physically based rendering method BlenderProc and procedures for data creation are provided for further research and investigations. Then, the performance of synthetic datasets are evaluated by object detection models(Yolov5 [22] and Yolov8 [23]) and a pose estimation model (Wide Depth Range [20]). Also, the influences of applying domain randomization methods(e.g. adding distarctors into the synthetic dataset) is discussed and evaluated. By evaluating the experiment results, the study finds that similar objects will cause mis-classification problems in connectors detection tasks, the domain gap will lead to a poor performance on real data and adding distractors into synthetic dataset can improve the robustness of the detectors. The study concludes with recommendations for future research, such as using Generative Adversarial Networks (GANs) to transfer the overall color and texture from the source images to the target images, or apply a bilevel optimization approach. These kinds of methods improve the domain gap between synthetic data and real data, thereby improving the performance of models trained on synthetic datasets in the future