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Item type:Publication, Access status: with files , ASV-aided AUV navigation: A field study on nonlinear estimation for localization of low-cost, scalable systems(IEEE, 2025-11-27); ; ; ; Benjamin, MichaelThis work investigates the use of multiple Autonomous Surface Vehicles (ASVs) as Communication/Navigation Aids (CNAs) to enhance the navigation and state estimation of an Autonomous Underwater Vehicle (AUV). Our approach builds on recent advancements in low-cost sensors and platforms, which enable novel AUV applications across fundamental science, commercial industries, and defense. We consider six different combinations of Kalman Filter and Factor Graph localization solutions on three datasets, covering 53 minutes and 3.1 kilometers of operation. We first present the solution using the measurements from all three ASVs, before occluding measurements from two of the ASVs to assess the effect of reduced observability on localization performance.Publicationtype: Conference Paper54 46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Experimental open-source framework for underwater pick-and-place studies with lightweight UVMS – an extensive quantitative analysisThe rise of lightweight, low-cost underwater vehicle-manipulator systems (UVMS) has made autonomous underwater manipulation increasingly accessible. Yet, most current research remains limited to isolated tasks, such as trajectory tracking or compensation of unknown payloads. Detailed experimental analyses that go beyond a proof-of-concept are particularly rare.We present a comprehensive open-source software framework for fully automated pick-and-place studies. We build upon our previous work on a task-priority control framework and extend it to enable fully autonomous manipulation. This includes a high-level decision-making process to coordinate the pick-and-place sequence and a grasp detection method to verify the successful pick-up of the object. We demonstrate this framework on the widely-used platform of a BlueROV2 and an Alpha 5 manipulator.Extensive quantitative experimental studies (100+ trials) show the picking and placing to be highly accurate, with mean position errors of <5 mm and <10 mm, respectively. We additionally validate our grasp detection approach and analyze trajectory tracking sensitivity to varying payloads and speeds. These results provide a baseline of what accuracy is currently achievable with state-of-the-art lightweight hardware under ideal research conditions. The code is available at https://github.com/HippoCampusRobotics/uvms.Publicationtype: Conference Paper126 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Dynamic end effector trajectory tracking for small-scale underwater vehicle-manipulator systems (UVMS): modeling, control, and experimental validation(IEEE, 2025-05); ; ; ; With the ongoing miniaturization, recently, lightweight, commercial underwater vehicle-manipulator systems (UVMSs) have emerged that massively lower the entry barrier into underwater manipulation. Within this research field, dynamic and accurate end effector trajectory tracking is a crucial first step in developing autonomous capabilities. In this context, coupling effects between the manipulator and vehicle dynamics are expected to pose a considerable challenge. However, UVMS control strategies analyzed in detailed experimental studies are particularly rare. We present a holistic approach based on task-priority control that we describe and discuss from modeling towards extensive experimental studies, which are crucial for the notoriously hard-to-simulate underwater domain. We demonstrate this framework on the widely used platform of a BlueROV2 and an Alpha 5 manipulator. The end effector trajectory tracking is shown to be highly accurate, with <4 cm median position error. Moreover, our experimental findings on the consideration of dynamic coupling within UVMS control motivate further research. The code is available at https://github.com/HippoCampusRobotics/uvms. A video of the results is available at https://youtu.be/IDM1I5KqlVI.Publicationtype: Conference Paper107 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Predicting against the Flow : Boosting Source Localization by Means of Field Belief Modeling using Upstream Source Proximity(IEEE, 2024-08-08); ; ; ; Time-effective and accurate source localization with mobile robots is crucial in safety-critical scenarios, e.g. leakage detection. This becomes particular challenging in realistic cluttered scenarios, i.e. in the presence of complex current flows or wind. Traditional methods often fall short due to simplifications or limited onboard resources. We propose to combine source localization with a Gaussian Markov Random Field (GMRF). This allows to improve source localization hypotheses by building on the GMRF's concentration and flow field belief that are continuously updated by gathered measurements. We introduce the upstream source proximity (USP) as a natural metric that exploits the joint knowledge represented in the field belief's concentration and flow field, i.e. predicting sources upstream. As a result, our method yields a computationally efficient source localization and field belief module providing substantially more stable gradients than conventional concentration gradient-based methods.We demonstrate the suitability of our approach in a series of numerical experiments covering complex source location scenarios. With regard to computational requirements, the method achieves update rates of 10Hz on a RaspberryPi4B.Publicationtype: Conference Paper34 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Towards Full Actuation: Reconfigurable Micro Underwater Robots(IEEE, 2023-10-01); ; ; ; Exploration and monitoring of hazardous environments, such as legacy nuclear storage ponds, constitute safety-critical missions to be performed by small-scale underwater robots. These monitoring tasks require fully actuated robot platforms in order to allow for hovering while inspecting objects of interest in detail. A severe bottleneck arises from the restricted access points commonly encountered in these surveillance missions that pose strict limitations on the vehicle dimensions. However, small-scale underwater robots usually possess underactuated propulsion systems and are, thus, only partially suitable for these missions. In this work, we investigate and exploit the idea of reconfigurability. Following the idea of the whole is more than the sum of its parts, we daisy-chain multiple small-scale underwater robots with revolute joints to enable shape reconfigurations. In combination with a centralized sliding mode control scheme, the robot platform is able to change its shape depending on the current task, see Fig. 1. While the straight configuration fits well through tight passages such as inspection holes, the robot can reconfigure itself towards a triangular shape that enables the neutrally buoyant robot to hover at areas of interest, e. g. for inspection tasks. Finally, we examine our proposed concept in a series of simulations and experiments. Moreover, we demonstrate the performance of key elements such as reconfiguration and navigation, discuss their limitations, and point out future directions.Publicationtype: Conference Paper40 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Evaluation of Underwater AprilTag Localization for Highly Agile Micro Underwater RobotsAccurate localization systems are still a bottleneck for Unmanned Underwater Vehicles (UUVs). In recent years, fiducial markers have become a readily available, low-cost option. However, an in-depth analysis of marker detection accuracy in the underwater domain has yet to be performed. We propose a methodology to evaluate fiducial marker systems, namely the popular AprilTag system, in experiments. Our study especially focuses on aspects crucial for highly agile micro underwater robots, such as dynamic motions and the calibration medium. This class of robots is typically extensively studied in research tanks which motivates a first focus on clear-water settings. However, the proposed method and the findings can be transferred to similar scenarios. We demonstrate the importance of calibrating underwater and that the detection accuracy decreases linearly with camera distance and could therefore easily be compensated for. Moreover, we identify a suitable camera that maximizes the detection rate during highly dynamic motions. In sum, this work is an initial step towards application-relevant design strategies for designing low-cost, accessible localization systems for agile, mobile robots.Publicationtype: Conference Paper80 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Image-Based Visual Servoing Switchable Leader-follower Control of Heterogeneous Multi-agent Underwater Robot System(2023-05); ; ; Scopus© Citations 2 57 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , UWRange : an open ROS framework for simulating acoustic ranging and localization for underwater robots under realistic conditions(IEEE, 2022-10); ; ; ; Publicationtype: Conference Paper255 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Towards coupling land-based and water-based mobile robots for monitoring and inspection of waterside structures(2022-05-23); ; ; ; Waterside structures represent vulnerable and often safety-relevant land/water interfaces that fulfill critical operations, such as facilitating commute across natural impediments or protecting and managing marine traffic. Therefore, monitoring and inspection of waterside structures is essential to ensure continuous operation. With recent technological advancements, robotic systems have been devised to execute monitoring and inspection tasks. However, robotic monitoring and inspection of waterside structures, as compared to monitoring and inspection of land-based civil infrastructure systems, is associated with a number of challenges because of the specifics of waterside structures. In particular, the collaboration of land-based and water-based robots must be ensured, which, so far, has received little attention in robotics research. This paper proposes a concept to couple land-based and water-based robots for monitoring and inspection of waterside structures. The concept is centered around collaborative analysis of the structural condition, and it builds upon embedded computing considering the semantics provided by digital twins and building information models. Finally, research directions are discussed that need to be investigated for transferring the concept into engineering practice.Publicationtype: Conference Paper130 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Workshop: Adaptive Structures At Shore 2022 : 23rd & 24th of May 2022, Hamburg, Germany : conference proceedings(Technische Universität Hamburg, 2022-05-23); ; ; ; Adaptive structures at shore provide an opportunity to minimize the resource consumption and the impact on the marine ecosystems through an efficient adaptation to changing boundary conditions. A combination of impact prediction, monitoring and material resistance estimation, numerical modelling, and innovative design is the key to success. The workshop “Adaptive Structures at Shore 2022” hosted by Hamburg University of Technology (TUHH) brings together international scientists and professionals to discuss the latest developments in the field and to explore synergies.Publicationtype: Conference Proceedings308 171