@masterthesis{OberhoferGruber, type = {Bachelor Thesis}, author = {Oberhofer, Marika and Gruber, Ramona}, title = {Feuchte in Tunnelinnenschalen. Eine Literaturstudie}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-20635}, school = {Ostbayerische Technische Hochschule Regensburg}, language = {de} } @masterthesis{Gering, type = {Bachelor Thesis}, author = {Gering, Stefan}, title = {Thermische Detailsimulationen in der Bestandssanierung}, address = {Regensburg}, language = {de} } @masterthesis{Zhang, type = {Bachelor Thesis}, author = {Zhang, Yunjia}, title = {Microcontroller Programming of a Contactless Optical Position Measurement Device}, address = {Regensburg}, doi = {10.35096/othr/pub-8464}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-84647}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {37}, abstract = {This thesis focuses on programming a microcontroller to receive and process data from a waveguide optic distance sensor, and to visualize the measured distance on a display screen. During the measurement process, LED moves above the 3D-printed D-shaped waveguide. The light transmitted through the waveguide is converted into photocurrents by photodiodes located at both ends of the optical waveguide, which are then converted into voltage signals through specific electronic components. By computing the ratio of the optical power detected at each end, the relative position of the LED along the waveguide can be determined. In this project, a microcontroller is used to acquire the voltage data, correct measurement errors, calculate the LED position, and display the result on screen in real time. Compared to manual calculation of photocurrent values, using a microcontroller for automated data processing greatly improves speed and efficiency. At the same time, real-time visualization enhances the system's practicality and usability, making it more suitable for future applications.}, language = {en} } @masterthesis{Zhong, type = {Bachelor Thesis}, author = {Zhong, Gantong}, title = {Calibration and Performance Evaluation of Contactless Optical Position Sensors Based on 3D Printed Optical Waveguides}, address = {Regensburg}, doi = {10.35096/othr/pub-8466}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-84668}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {35}, abstract = {This work presents the design, implementation, and performance evaluation of a positionsensing system based on a 3D printed optical waveguide. Building upon the conceptual foundation of D-shaped polymer optical fiber (POF) sensors [1], this study introduces a novel waveguide structure fabricated via multi-material fused filament fabrication (FFF) 3D printing. The waveguide incorporates a square-core geometry with integrated mechanical brackets and selective black cladding layer to enhance optical confinement and minimize boundary-induced nonlinearity. Three successive design iterations were developed and evaluated, with each version refined based on calibration results and structural observations. The final version demonstrated high fabrication stability and improved optical behavior, enabling consistent calibration across multiple samples. Using a center-corrected linear attenuation model, the position of a side-coupled LED was estimated from dual photodiode signals and compared with true light source position. The measurement results for five independently printed waveguides show mean absolute errors below 0.2 mm and standard deviations as low as 0.268 mm. The sensor response was found to be highly linear over the 5-55 mm sensing range, with worst-case errors bounded within ±1.7 mm. Compared with traditional D-shaped POF sensors, where performance is limited by manual polishing variability and nonuniform attenuation, the 3D-printed approach offers superior linearity, submillimeter accuracy, and batch-to-batch reproducibility. These findings prove the feasibility of 3D-printed optical waveguides in scalable and precise position sensing applications, marking a further step toward the batch fabrication and and potential industrialization of contactless optical position sensors. A conclusion of the research findings and suggestions for future improvements were provided at the end of this thesis, offering insights for the further development in this area.}, language = {en} } @masterthesis{Xu, type = {Bachelor Thesis}, author = {Xu, Zhiming}, title = {Electronic circuit design and implementation of a contactless optical position measurement device}, address = {Regensburg}, doi = {10.35096/othr/pub-8520}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-85201}, school = {Ostbayerische Technische Hochschule Regensburg}, pages = {49}, abstract = {This thesis presents the design and implementation of a low-cost, highprecision analog front-end for a non-contact optical displacement measurement system. While the principle of sensing based on D-shaped optical fibers is well-established, its practical replication faces challenges of poor consistency from manual polishing and high material costs. To address these issues, we employ 3D-printed polymer waveguides as the core sensing medium and design a dedicated signal conditioning circuit to accompany it. The core work of this thesis revolves around a dual-channel, two-stage amplifier analog front-end. The circuit converts weak, nanoampere-level (nA) photocurrents from the photodiodes into voltage signals. These signals are stable, linear, and suitable for the microcontroller (MCU) to process. The entire design follows this workflow: starting from theoretical calculations, the circuit's performance in frequency domain, time domain, and noise was verified through LTspice simulation. Subsequently, the design was realized in hardware via PCB implementation, including guard rings. The experimental results show that the performance of the fabricated circuit is consistent with simulation. When integrated with the 3D-printed waveguide, the complete system performed end-to-end calibration and decoding. Over a 50 mm measurement range, the system achieved a maximum absolute error of less than 0.81 mm and a root mean square error below 0.4 mm. This research validates the feasibility of a complete, low-cost, non-contact displacement measurement solution—from the sensing structure to the signal processing—suitable for small-scale use.}, language = {en} }