A5058640048- Adaptive optics and wavefront sensing
- Optical Wireless Communication Technologies
- Advanced optical system design
- Robotics and Sensor-Based Localization
- Optical Systems and Laser Technology
- Spacecraft Design and Technology
- Infrared Target Detection Methodologies
- Advanced Measurement and Metrology Techniques
- Satellite Communication Systems
- UAV Applications and Optimization
- Piezoelectric Actuators and Control
- Advanced Optical Sensing Technologies
- Electric Motor Design and Analysis
- Astronomical Observations and Instrumentation
- Space Satellite Systems and Control
- Advanced Control and Stabilization in Aerospace Systems
- Force Microscopy Techniques and Applications
- Advanced Fiber Optic Sensors
- Iterative Learning Control Systems
- Welding Techniques and Residual Stresses
- Advanced Surface Polishing Techniques
- Induction Heating and Inverter Technology
- Remote Sensing and LiDAR Applications
- Image Processing Techniques and Applications
- Inertial Sensor and Navigation
TU Wien
2015-2024
University of Applied Sciences Technikum Wien
2019-2024
Recent advancements in free-space optical (FSO) communications are enabling a breakthrough satellite miniaturization and data transfer rates. The CubeISL laser communication terminal (LCT), development of the German Aerospace Center (DLR), is set to showcase inter-satellite links at 100 Mbps downlinks 1 Gbps once it launches 2025. This technology aims establish itself as cutting-edge solution for efficient CubeSat communications, delivering high To validate its capabilities, underwent...
In recent years, substantial technological development has made unmanned aerial vehicles (UAVs) more versatile, cheaper, and accessible to the public. Alongside many positive effects use cases, safety concerns are increasing as a plethora of incidents demonstrate destructive potential UAVs. To counteract this and, thus, protect people critical infrastructure, UAV detection, tracking, defense gained research attention. Whereas different drone detection technologies such RADAR, radio...
This paper presents the implementation of a multi-threaded parallel architecture, which enables telescope-based optical UAV detection and tracking in real-time. For efficient image processing an accurate deep learning object detector is complemented by fast tracker. A transition strategy between tracker introduced based on reliability, improves localization accuracy system. The algorithm initializes subsequent frames reliability compared to confidence value each newly detected determine...
This paper presents the analysis, implementation and experimental evaluation of a high-speed automatic focus module for telescope-based UAV detection tracking system. An existing optical drone system consisting two telescopes deep learning-based object is supplemented by suitable linear stages passive algorithms to enable fast adjustment. Field tests with proposed demonstrate that UAVs flying at speeds up 24 m/s towards are successfully tracked kept in from more than 4500 m down 150 m....
A six degree of freedom, magnetically levitated metrology platform is proposed and implemented to enable nano-scale measurements directly in a production environment by providing vibration isolation. The maintains constant distance between sample nano-metrology tool, forming laboratory the line. This paper presents design platform. Tracking achieved using position sensors, freedom actuator feedback control. Experimental results demonstrate positioning degrees at bandwidth 35 Hz translational...
Zusammenfassung In einer Produktionsumgebung beeinflussen mechanische Vibrationen den Relativabstand zwischen Inspektionsgerät und Werkstück, was für Messungen im Nanometerbereich hinderlich ist. Dieser Beitrag stellt eine Metrologieplattform zur Montage eines Inspektionsgerätes vor, die mittels H ∞ -Reglers zum Werkstück konstant hält. Ein Laboraufbau mit einem Freiheitsgrad zeigt, dass in der vorkommende um Größenordnung reduziert werden können, Oberflächencharakterisierung direkt...
In hybrid reluctance actuators for high precision motion control, the magnetic hysteresis in ferromagnetic stator and mover usually affects precision. Therefore, this paper proposes flux estimation control to compensate hysteresis. To measure at various frequencies, output signal of a search coil is combined with that current monitor employed amplifier estimator. Finally, controller designed implemented. For evaluation compensation, performance actuator compared both control. Experimental...
Mechanical vibrations resulting from wind, ground and actuator imperfections lower the performance of optical telescope systems used for astronomical applications, as well free-space communication. This paper proposes a high-bandwidth tip-tilt compensation system telescopes, in order to reduce influence these vibrations. A typical, high precision, motorized is base this evaluation. By utilization sensor, errors are measured analyzed frequency domain. fast steering mirror integrated into path...
This paper presents a comparison between grayscale and color-based deep learning algorithms for long distance optical UAV detection using robotic telescope systems. Three object are trained with custom dataset consisting of RGB images the performance is evaluated against same converted to grayscale. Network training from scratch fine-tuning evaluated. The results all show that maximizes scores about 5% better in terms mean average precision (mAP(0.5)) compared on images.
This paper presents the design and implementation of a scalable laser ranger finder (LRF)-based prototype system, which enables distance measurement precise localization multiple unmanned aerial vehicles (UAVs) in real-time. The system consists telescope camera as image acquisition components, supplemented by an LRF fast steering mirror (FSM) to obtain measurement. By combining optical path through dichroic mirror, is accurately aligned FSM based on angular position UAV within field view....
Midsized telescopes currently receive a lot of interest due to their application in free space optical communication and debris observation. This paper analyzes an active mirror support system very thin meniscus with diameter 1 m 25 mm thickness for the lightweight, low-cost telescope. An analytic model self-weight surface deflection is used determine number concentric continuous rings find radii sufficiently mirror. The obtained are as initial value finite element analysis include shear...
Nano-satellites, which are following the CubeSat standard have established for demanding industrial and scientific applications with critical requirements on reliability radiation tolerance. The employment of commercial off-the-shelf components enables a state-of-the-art performance but requires extensive testing to avoid mitigate malefunctions due space environment. mission CLIMB is representative future missions complex payload, high power budget harsh exposure. For this reason,...
This paper evaluates the required resolution of a telescope system experimentally to enable reliable deep learning-based long-range UAV detection. FRCNN, state-of-the-art learning object detector is fine-tuned for detection with custom dataset. A test dataset has been created small in front clear and complex background at distances ranging from 500m up 2500m using focal length 1325mm an aperture 102 mm. At each distance measured modified version US Air Force chart. The results show that...
This publication presents an active compensation system for the position of secondary mirror a small Ritchey–Chrétien telescope system. The goal is to maintain optical imaging quality under varying gravitational and thermal influences, by relative deviations between primary mirrors. An extensive analysis concerning feasibility such commercial off-the-shelf performed used as basis design precision measurement positioning developed prototype uses dimensional metrology capture errors mirror. A...
This publication investigates the applicability of feed-forward vibration compensation for small telescope systems in one axis, based on commercial-off-the-shelf accelerometers and a fast-steering mirror (FSM). The vibrations are measured with multiple their influence onto optical path is reconstructed using highpass filtered double integrator. Consequently, deviations compensated control manner by FSM. A quad-photo-diode an artificial star used verification performance system. Exemplary...
Atmospheric turbulences limit the achievable performance of free-space optical (FSO) satellite communication systems. Particularly in retro-reflective FSO communication, tip-tilt disturbances are a dominant source degradation and thus prevent exploitation full potential this system. This publication investigates total error terrestrial platform for reflective using 14-inch telescope with compensation. The compensation system consists fast steering mirror (FSM), quad photo diode (QPD)...
We investigate the design of an active support system for thin primary mirror a mid-sized telescope used optical satellite communication and space debris observation. To handle complexity this task, general methodology is proposed. The axial lateral separated into several subtasks to reduce number variables in every step. Due independence geometry material, also applicable larger mirrors. Utilizing proposed procedure, 1-m meniscus with 25 mm thickness requirement achieve diffraction-limited...
This publication presents a high-bandwidth tip-tilt compensation system for small telescopes. It is designed with respect to the requirements of applications such as free-space optical (FSO) communication and space debris imaging, where high tracking speeds up several degrees per second are required lead an increased disturbance bandwidth. A quad-photo-diode (QPD) used measure errors compensate them in closed-loop manner by fast-steering mirror (FSM). Feedback controllers based on measured...