Alexander Julian Golkowski

@inproceedings{9287891,
title = {Quantifying the Impact of the Physical Setup of Stereo Camera Systems on Distance Estimations},
author = {Alexander Julian Golkowski and Marcus Handte and Peter Roch and Pedro José Marrón},
doi = {10.1109/IRC.2020.00041},
year = {2020},
date = {2020-01-01},
booktitle = {2020 Fourth IEEE International Conference on Robotic Computing (IRC)},
pages = {210-217},
abstract = {The ability to perceive the environment accuratelyis a core requirement for autonomous navigation. In the past,researchers and practitioners have explored a broad spectrumof sensors that can be used to detect obstacles or to recognizenavigation targets. Due to their low hardware cost and highfidelity, stereo camera systems are often considered to be aparticularly versatile sensing technology. Consequently, there hasbeen a lot of work on integrating them into mobile robots.However, the existing literature focuses on presenting theconcepts and algorithms used to implement the desired robotfunctions on top of a given camera setup. As a result, the rationaleand impact of choosing this camera setup are usually neitherdiscussed nor described. Thus, when designing the stereo camerasystem for a mobile robot, there is not much general guidancebeyond isolated setups that worked for a specific robot.To close the gap, this paper studies the impact of the physicalsetup of a stereo camera system in indoor environments. To dothis, we present the results of an experimental analysis in whichwe use a given software setup to estimate the distance to anobject while systematically changing the camera setup. Thereby,we vary the three main parameters of the physical camerasetup, namely the angle and distance between the cameras aswell as the field of view. Based on the results, we derive severalguidelines on how to choose the parameters for an application.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{sascha19lcn,
title = {Where are You? Localising Stationary Nodes with Limited Information},
author = {Sascha Jungen and Matteo Ceriotti and Valentin Fitz and Alexander Julian Golkowski and Pedro José Marrón},
year = {2019},
date = {2019-10-14},
booktitle = {Proceedings of the IEEE 44th Conference on Local Computer Networks (LCN)},
address = {Osnabrück, Germany},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{2285-2286,
title = {RCS Investigation of Tetrahedral Aligned Sphere Targets for Radar Positioning},
author = {Christian Schulz and Michael Gerding and Timo Jaeschke and Alexander Julian Golkowski and Nils Pohl},
doi = {10.1109/APUSNCURSINRSM.2018.8608913},
year = {2018},
date = {2018-01-01},
booktitle = {2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting},
pages = {2285-2286},
abstract = {This contribution presents the investigation of tetrahedral aligned sphere targets and their effect on radar measurements via sinograms. Here, the radar cross section (RCS) is evaluated in order to determine the distance and angle between radar and target for precise 3D industrial robot positioning. Therefore, the sinograms are simulated by a shooting and bouncing ray approach with CST Microwave Studio. Two different targets are investigated: One with equally sized and and one with differently sized spheres. While the former has ambiguities, which only allow an angle estimation within a certain range, the latter reduces these ambiguousness towards zero.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{8617573,
title = {Investigation of a 3D Printed Tetrahedral Aligned Sphere Target at 145 GHz for Radar Positioning},
author = {Christian Schulz and Michael Gerding and Timo Jaeschke and Alexander Julian Golkowski and Nils Pohl},
doi = {10.23919/APMC.2018.8617573},
year = {2018},
date = {2018-01-01},
booktitle = {Investigation of a 3D Printed Tetrahedral Aligned Sphere Target at 145 GHz for Radar Positioning
},
pages = {381-383},
organization = {2018 Asia-Pacific Microwave Conference (APMC)},
abstract = {A 3D printed tetrahedral aligned sphere target and its effect on FMCW radar measurements at 145 GHz are investigated in this paper. The target itself contains four differently sized metallic spheres connected by cylindrical holders. This yields an unambiguous reflection behaviour over all angles. For the evaluation, sinograms are simulated and measured in order to determine the distance and the angle between radar and target as well as the radar cross section (RCS). This allows for unambiguous angle estimations. One possible field of application is precise 3D industrial robot positioning. The simulations are performed by CST Microwave Studio using a shooting and bouncing ray approach to obtain the simulation results very fast compared to full 3D electromagnetic field simulations. Final measurements with aD-band FMCW radar prove the applicability of the presented 3D printed tetrahedral aligned sphere target.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{10.1145/2999504.3001076,
title = {Acoustic Modem for Micro AUVs: Design and Practical Evaluation},
author = {Christian Renner and Alexander Julian Golkowski},
doi = {10.1145/2999504.3001076},
isbn = {9781450346375},
year = {2016},
date = {2016-01-01},
booktitle = {Proceedings of the 11th ACM International Conference on Underwater Networks & Systems},
pages = {1-8},
abstract = {The recent development of small, cheap AUVs such as MONSUN and Hippocampus enables a plethora of applications for underwater inshore monitoring. Among these are the detection of pollution sources in ports, water-quality monitoring in lakes, and the support and protection of divers in context of disaster management. These tasks profit from online reporting and controlling as well as swarm interaction between the AUVs. For this purpose, communication is required. In this paper, we present a prototype of an acoustic modem that is (i) small enough to be carried by micro AUVs in the sub 10 L class, (ii) consumes little enough energy to not diminish operation times of its host, (iii) comes at an attractive unit cost of less than €600, and (iv) can reliably communicate at distances of 50m and more. Due to its modular build, the modem can be easily customized and is hence suitable as research platform to analyze, e.g., MAC and routing protocols. We present results of detailed real-world studies of its communication range, packet reception rate, and ranging accuracy.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{10.5555/2893711.2893750,
title = {Poster: Affordable Acoustic Modem for Small-Sized Autonomous Underwater Vehicles},
author = {Christian Renner and Alexander Julian Golkowski and Erik Maehle},
isbn = {9780994988607},
year = {2016},
date = {2016-01-01},
booktitle = {Proceedings of the 2016 International Conference on Embedded Wireless Systems and Networks},
pages = {235-236},
abstract = {The development of small, cheap AUVs offers a plethora of applications for underwater inshore monitoring. For online reporting and controlling as well as swarm interaction, communication is required. We present a prototype of an acoustic modem that is (i) small enough to be carried by small-sized AUVs in the sub 10 L class, (ii) consumes little enough energy to not diminish operation times of its host, (iii) comes at a much lesser unit cost than commercial solutions. Our evaluation indicates that communication is reliable at distances up to 43 m and beyond.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}