|Alexander Julian Golkowski
- Image processing for mobile robots
- High accuracy landing for drones
- Autonomous Underwater Vehicle
- VR/AR based mobile robot control
- Master of Science – Universität zu Lübeck, Computer Science – Field of Application: Robotics and Automation, 2016
- Bachelor of Science – Universität zu Lübeck, Computer Science – Field of Appliaction: Robotics and Automation, 2015
- IEEE Membership
- GI – Gesellschaft für Informatik
|Sayedsepehr Mosavat, Matteo Zella, Marcus Handte, Alexander Julian Golkowski, Pedro José Marrón: Experience: ARISTOTLE: wAke-up ReceIver-based, STar tOpology baTteryLEss sensor network. In: Proceedings of the 22nd International Conference on Information Processing in Sensor Networks, ACM Digital Library, 2023, ISBN: 979-8-4007-0118-4. (Type: Proceedings Article | | )
A truly ubiquitous, planet-wide Internet of Things requires ultra-low-power, long-lasting sensor nodes at its core so that it can be practically utilized in real-world scenarios without prohibitively high maintenance efforts. Recent advances in energy harvesting and low-power electronics have provided a solid foundation for the design of such sensor nodes. However, the issue of reliable two-way communication among such devices is still an active research undertaking due to the high energy footprint of traditional wireless transceivers. Although approaches such as radio duty cycling have proved beneficial for reducing the overall energy consumption of wireless sensor nodes, they come with trade-offs such as increased communication latency and complex protocols. To address these limitations, we propose ARISTOTLE, an ultra-low-power, wake-up receiver-based sensor node design employing a star network topology. We have deployed ARISTOTLE in two different venues for carrying out the task of weather data collection. In addition to reporting the results of the two deployments, we also evaluate several performance aspects of our proposed solution. ARISTOTLE has a mean power consumption of 236.67 uW while it is in sleep mode and monitoring the radio channel for incoming wake-up signals. Utilizing various sizes of supercapacitors, ARISTOTLE was able to reach system availabilities between 47.83% and 97.36% during our real-world deployments.
|Alexander Julian Golkowski, Marcus Handte, Pedro Jose Marron, Alexander Wedemeyer, Jakob Robert: A Low-Cost Binaural Hearing Support System for Mobile Robots. In: Proceedings of the 2023 International Conference on Robotics, Control and Vision Engineering, pp. 18–24, Association for Computing Machinery, Tokyo, Japan, 2023, ISBN: 9798400707742. (Type: Proceedings Article | | )
The ability to quickly obtain a comprehensive picture of the environment is an important prerequisite for the realization of robust and safe autonomous navigation with mobile robots. Due to their comparatively low computational requirements and cost, as well as their ability to provide omnidirectional perception, audio systems can be an excellent complement to more sophisticated or expensive sensing systems such as cameras or lidars. In this paper, we describe the development of a low-cost binaural audio system capable of interpreting the acoustic information present in an environment to assist a lidar system in making decisions that need to be made by a mobile robot. By taking advantage of the robot’s mobility, the system can resolve the uncertainties inherent in consciously choosing two off-the-shelf microphones and effectively realize 360-degree coverage. This opens up new possibilities, for example, to make room monitoring much more reliable.
|Alexander Julian Golkowski, Marcus Handte, Leon Alexander Marold, Pedro José Marrón: Simplifying the Control of Mobile Robots through Image-based Behaviors. In: 2022 2nd International Conference on Computer, Control and Robotics (ICCCR), pp. 52-57, 2022. (Type: Proceedings Article | | )
The development and commissioning of mobile robots is usually a time-consuming and cost-intensive undertaking. Today, systems are realized primarily through the use of complex software and hardware architectures, which only partially meet modern requirements for mobile robots. The core discipline that a mobile robot must fulfill is the correct perception of its environment. To achieve this, various technologies are used that are useful for detecting obstacles or navigating targets. An increasingly attractive technology in this domain are artificial neural networks. Existing literature focuses on either improving the performance of existing systems or on training for very specialized applications. In the field of mobile robotics, the focus is usually on realizing a specific task, while little attention is paid to generalizability, cost and energy constraints. To fill this gap, this paper investigates the possibility of reducing the setup for a mobile robot application to a minimum while still enabling complex behaviors. For the implementation, we take a biological inspired approach and investigate the usability of artificial neural networks, in this case YOLOv4, in a mobile robot application. In particular, we examine whether the currently available technologies meet todays requirements.
|Alexander Julian Golkowski, Marcus Handte, Peter Roch, Pedro José Marrón: An Experimental Analysis of the Effects of Different Hardware Setups on Stereo Camera Systems . In: International Journal of Semantic Computing, vol. 15, no. 3, pp. 337–357, 2021, ISSN: 1793-7108. (Type: Journal Article | | )
For many application areas such as autonomous navigation, the ability to accurately perceive the environment is essential. For this purpose, a wide variety of well-researched sensor systems are available that can be used to detect obstacles or navigation targets. Stereo cameras have emerged as a very versatile sensing technology in this regard due to their low hardware cost and high fidelity. Consequently, much work has been done to integrate them into mobile robots. However, the existing literature focuses on presenting the concepts and algorithms used to implement the desired robot functions on top of a given camera setup. As a result, the rationale and impact of choosing this camera setup are usually neither discussed nor described. Thus, when designing the stereo camera system for a mobile robot, there is not much general guidance beyond isolated setups that worked for a specific robot. To close the gap, this paper studies the impact of the physical setup of a stereo camera system in indoor environments. To do this, we present the results of an experimental analysis in which we use a given software setup to estimate the distance to an object while systematically changing the camera setup. Thereby, we vary the three main parameters of the physical camera setup, namely the angle and distance between the cameras as well as the field of view and a rather soft parameter, the resolution. Based on the results, we derive several guidelines on how to choose the parameters for an application.
|Alexander Julian Golkowski, Marcus Handte, Peter Roch, Pedro José Marrón: Quantifying the Impact of the Physical Setup of Stereo Camera Systems on Distance Estimations. In: 2020 Fourth IEEE International Conference on Robotic Computing (IRC), pp. 210-217, 2020. (Type: Proceedings Article | | )
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.
|Sascha Jungen, Matteo Ceriotti, Valentin Fitz, Alexander Julian Golkowski, Pedro José Marrón: Where are You? Localising Stationary Nodes with Limited Information. In: Proceedings of the IEEE 44th Conference on Local Computer Networks (LCN), Osnabrück, Germany, 2019. (Type: Proceedings Article | )
|Christian Schulz, Michael Gerding, Timo Jaeschke, Alexander Julian Golkowski, Nils Pohl: RCS Investigation of Tetrahedral Aligned Sphere Targets for Radar Positioning. In: 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, pp. 2285-2286, 2018. (Type: Proceedings Article | | )
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.
|Christian Schulz, Michael Gerding, Timo Jaeschke, Alexander Julian Golkowski, Nils Pohl: Investigation of a 3D Printed Tetrahedral Aligned Sphere Target at 145 GHz for Radar Positioning. In: Investigation of a 3D Printed Tetrahedral Aligned Sphere Target at 145 GHz for Radar Positioning
, pp. 381-383, 2018 Asia-Pacific Microwave Conference (APMC) 2018. (Type: Proceedings Article | | )
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.
|Christian Renner, Alexander Julian Golkowski: Acoustic Modem for Micro AUVs: Design and Practical Evaluation. In: Proceedings of the 11th ACM International Conference on Underwater Networks & Systems, pp. 1-8, 2016, ISBN: 9781450346375. (Type: Proceedings Article | | )
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.
|Christian Renner, Alexander Julian Golkowski, Erik Maehle: Poster: Affordable Acoustic Modem for Small-Sized Autonomous Underwater Vehicles. In: Proceedings of the 2016 International Conference on Embedded Wireless Systems and Networks, pp. 235-236, 2016, ISBN: 9780994988607. (Type: Proceedings Article | )
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.