VLDB 2026 Research / reviewers in the wild / expert
Simon Schaefer
dblp:209/9697
· DBLP profile ↗
12ranked-venue papers
5as first author
12since 2021 · last 2026
0000-0001-7289-6000ORCID · corroborated
Domains — the database's venue-derived domains; a paper can count in several
Artificial intelligence and machine learning · 10 · 4 first-author · 10 since 2021Systems, architecture and hardware · 7 · 3 first-author · 7 since 2021Graphics, computer vision, multimedia, augmented reality and games · 3 · 1 first-author · 3 since 2021Applied, interdisciplinary, general and emerging computing · 1 · 1 first-author · 1 since 2021
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | GSFix3D: Diffusion-Guided Repair of Novel Views in Gaussian SplattingabstractRecent developments in 3D Gaussian Splatting have significantly enhanced novel view synthesis, yet generating high-quality renderings from extreme novel viewpoints or partially observed regions remains challenging. Meanwhile, diffusion models exhibit strong generative capabilities, but their lack of awareness of specific scene information hinders accurate 3D reconstruction tasks. To address these limitations, we introduce GSFix3D, a novel framework that improves the visual fidelity in under-constrained regions by distilling prior knowledge from diffusion models into 3D representations, while preserving consistency with observed scene details. At its core is GSFixer, a latent diffusion model obtained via our customized finetuning protocol that can leverage both mesh and 3D Gaussians to adapt pretrained generative models to a variety of environments and artifact types from different reconstruction methods, enabling robust novel view repair for unseen camera poses. Moreover, we propose a random mask augmentation strategy that empowers GSFixer to plausibly inpaint missing regions. Experiments on challenging benchmarks demonstrate that our GSFix3D and GSFixer achieve state-of-the-art performance, requiring only minimal scene-specific fine-tuning on captured data. Realworld test further confirms its resilience to potential pose errors. Our code and data are publicly available: https://github.com/GSFix3D/GSFix3D. Jiaxin Wei 0001, Stefan Leutenegger, Simon Schaefer |
3DV | 3 |
| 2025 | SuperEvent: Cross-Modal Learning of Event-Based Keypoint Detection for SLAM
Yannick Burkhardt, Simon Schaefer, Stefan Leutenegger |
ICCV | 2 |
| 2025 | Scalable Outdoors Autonomous Drone Flight with Visual-Inertial SLAM and Dense Submaps Built without LiDARabstractAutonomous navigation is needed for several robotics applications. In this paper we present an autonomous Micro Aerial Vehicle (MAV) system which purely relies on cost-effective and light-weight passive visual and inertial sensors to perform large-scale autonomous navigation in outdoor, unstructured and cluttered environments. We leverage visual-inertial simultaneous localization and mapping (VI-SLAM) for accurate MAV state estimates and couple it with a volumetric occupancy submapping system to achieve a scalable mapping framework which can be directly used for path planning. To ensure the safety of the MAV during navigation, we also propose a novel reference trajectory anchoring scheme that deforms the reference trajectory the MAV is tracking upon state updates from the VI-SLAM system in a consistent way, even upon large state updates due to loop-closures. We thoroughly validate our system in both real and simulated forest environments and at peak velocities up to 3 m/s – while not encountering a single collision or system failure. To the best of our knowledge, this is the first system which achieves this level of performance in such an unstructured environment using low-cost passive visual sensors and fully on-board computation, including VI-SLAM. Code available at https://github.com/ethz-mrl/mrl_navigation. Sebastián Barbas Laina, Simon Boche, Sotiris Papatheodorou, Dimos Tzoumanikas, Simon Schaefer, Hanzhi Chen, Stefan Leutenegger |
IROS | 5 |
| 2025 | Int-HRL: towards intention-based hierarchical reinforcement learningabstractAbstract While deep reinforcement learning (RL) agents outperform humans on an increasing number of tasks, training them requires data equivalent to decades of human gameplay. Recent hierarchical RL methods have increased sample efficiency by incorporating information inherent to the structure of the decision problem but at the cost of having to discover or use human-annotated sub-goals that guide the learning process. We show that intentions of human players, i.e. the precursor of goal-oriented decisions, can be robustly predicted from eye gaze even for the long-horizon sparse rewards task of Montezuma’s Revenge–one of the most challenging RL tasks in the Atari2600 game suite. We propose Int-HRL: Hierarchical RL with intention-based sub-goals that are inferred from human eye gaze. Our novel sub-goal extraction pipeline is fully automatic and replaces the need for manual sub-goal annotation by human experts. Our evaluations show that replacing hand-crafted sub-goals with automatically extracted intentions leads to an HRL agent that is significantly more sample efficient than previous methods. Anna Penzkofer, Simon Schaefer, Florian Strohm, Mihai Bâce, Stefan Leutenegger, Andreas Bulling |
Neural Comput. Appl. | 2 |
| 2024 | Development of a Drive Unit for a Medical Breast PumpabstractThis paper presents a cooperative project, supported by the German government, between the University of Wuppertal and a company in the medical sector. The paper includes the construction of the drive unit and explains the main features of the mechanics and electronics being developed. These pumps are designed for a niche between medical devices and consumer hardware. To enable mobile usage, the new pump must be lighter and smaller than the existing ones. It should also have a water-proof housing for faster disinfection. The pump is designed so that both breasts can be treated individually. An integrated touch display and Bluetooth Low-Energy connectivity shall provide an easy operation and documentation. For predictive maintenance aspects the pump transmits data to a server via LTE. Simon Schaefer, Sascha Kratz, Stefan Soter |
HealthCom | 1 |
| 2024 | Online Tree Reconstruction and Forest Inventory on a Mobile Robotic SystemabstractTerrestrial laser scanning (TLS) is the standard technique used to create accurate point clouds for digital forest inventories. However, the measurement process is demanding, requiring up to two days per hectare for data collection, significant data storage, as well as resource-heavy post-processing of 3D data. In this work, we present a real-time mapping and analysis system that enables online generation of forest inventories using mobile laser scanners that can be mounted e.g. on mobile robots. Given incrementally created and locally accurate submaps—data payloads—our approach extracts tree candidates using a custom, Voronoi-inspired clustering algorithm. Tree candidates are reconstructed using an algorithm based on the Hough transform, which enables robust modeling of the tree stem. Further, we explicitly incorporate the incremental nature of the data collection by consistently updating the database using a pose graph LiDAR SLAM system. This enables us to refine our estimates of the tree traits if an area is revisited later during a mission. We demonstrate competitive accuracy to TLS or manual measurements using laser scanners that we mounted on backpacks or mobile robots operating in conifer, broad-leaf and mixed forests. Our results achieve RMSE of 1.93 cm, a bias of 0.65 cm and a standard deviation of 1.81 cm (averaged across these sequences)—with no post-processing required after the mission is complete. Leonard Freißmuth, Matías Mattamala, Nived Chebrolu, Simon Schaefer, Stefan Leutenegger, Maurice Fallon |
IROS | 4 |
| 2023 | A Benchmark for Multi-Robot Planning in Realistic, Complex and Cluttered EnvironmentsabstractSeveral successful approaches exist for solving the complex problem of multi-robot planning and coordination. Due to the lack of adequate benchmarking tools, comparing these approaches and judging their suitability for use in realistic scenarios is currently difficult. Therefore, we propose an open-source benchmark suite that aims to close this gap. Unlike existing benchmarks, our approach uses full-stack multi-robot navigation systems in realistic 3D simulated environments from the intralogistic and household domains. Using the open-source frameworks ROS 2, Gazebo and RMF allows the user to add other robot platforms easily. The framework provides easy-to-use abstractions, typical metrics and interfaces to several established planning libraries for multi-robot systems. With all these features, our framework successfully aids practitioners and researchers in comparing multi-robot planning and coordination systems to the state of the art. Our experiments show how the proposed benchmark simplifies gaining insights on relevant close to real-life robotics use cases. Simon Schaefer, Luigi Palmieri, Lukas Heuer, Rüdiger Dillmann, Sven Koenig, Alexander Kleiner |
ICRA | 1 |
| 2023 | BodySLAM++: Fast and Tightly-Coupled Visual-Inertial Camera and Human Motion TrackingabstractRobust, fast, and accurate human state - 6D pose and posture - estimation remains a challenging problem. For real-world applications, the ability to estimate the human state in realtime is highly desirable. In this paper, we present BodySLAM++, a fast, efficient, and accurate human and camera state estimation framework relying on visual-inertial data. BodySLAM++ extends an existing visual-inertial state estimation framework, OKVIS2, to solve the dual task of estimating camera and human states simultaneously. Our system improves the accuracy of both human and camera state estimation with respect to baseline methods by 26 % and 12%, respectively, and achieves realtime performance at 15+ frames per second on an Intel i7-model CPU. Experiments were conducted on a custom dataset containing both ground truth human and camera poses collected with an indoor motion tracking system. Dorian Henning, Christopher L. Choi, Simon Schaefer, Stefan Leutenegger |
IROS | 3 |
| 2023 | GloPro: Globally-Consistent Uncertainty-Aware 3D Human Pose Estimation & Tracking in the WildabstractAn accurate and uncertainty-aware 3D human body pose estimation is key to enabling truly safe but efficient human-robot interactions. Current uncertainty-aware methods in 3D human pose estimation are limited to predicting the uncertainty of the body posture, while effectively neglecting the body shape and root pose. In this work, we present GloPro, which to the best of our knowledge the first framework to predict an uncertainty distribution of a 3D body mesh including its shape, pose, and root pose, by efficiently fusing visual clues with a learned motion model. We demonstrate that it vastly outperforms state-of-the-art methods in terms of human trajectory accuracy in a world coordinate system (even in the presence of severe occlusions), yields consistent uncertainty distributions, and can run in real-time. Our code will be released upon acceptance at https:$I$Igithub. coml smartroboticslab/GloPro. Simon Schaefer, Dorian Henning, Stefan Leutenegger |
IROS | 1 |
| 2022 | AEGNN: Asynchronous Event-based Graph Neural NetworksabstractThe best performing learning algorithms devised for event cameras work by first converting events into dense representations that are then processed using standard CNNs. However, these steps discard both the sparsity and high temporal resolution of events, leading to high computational burden and latency. For this reason, recent works have adopted Graph Neural Networks (GNNs), which process events as “static” spatio-temporal graphs, which are inherently “sparse”. We take this trend one step further by introducing Asynchronous, Event-based Graph Neural Networks (AEGNNs), a novel event-processing paradigm that generalizes standard GNNs to process events as “evolving” spatio-temporal graphs. AEGNNs follow efficient update rules that restrict recomputation of network activations only to the nodes affected by each new event, thereby significantly reducing both computation and latency for event-by-event processing. AEGNNs are easily trained on synchronous inputs and can be converted to efficient, “asynchronous” networks at test time. We thoroughly validate our method on object classification and detection tasks, where we show an up to a 200-fold reduction in computational complexity (FLOPs), with similar or even better performance than state-of-the-art asynchronous methods. This reduction in computation directly translates to an 8-fold reduction in computational latency when compared to standard GNNs, which opens the door to low-latency event-based processing. Simon Schaefer, Daniel Gehrig, Davide Scaramuzza 0001 |
CVPR | 1 |
| 2022 | Visual-Inertial SLAM with Tightly-Coupled Dropout-Tolerant GPS FusionabstractRobotic applications are continuously striving towards higher levels of autonomy. To achieve that goal, a highly robust and accurate state estimation is indispensable. Combining visual and inertial sensor modalities has proven to yield accurate and locally consistent results in short-term applications. Unfortunately, visual-inertial state estimators suffer from the accumulation of drift for long-term trajectories. To eliminate this drift, global measurements can be fused into the state estimation pipeline. The most known and widely available source of global measurements is the Global Positioning System (GPS). In this paper, we propose a novel approach that fully combines stereo Visual-Inertial Simultaneous Localisation and Mapping (SLAM), including visual loop closures, with the fusion of global sensor modalities in a tightly-coupled and optimisation-based framework. Incorporating measurement uncertainties, we provide a robust criterion to solve the global reference frame initialisation problem. Furthermore, we propose a loop-closure-like optimisation scheme to compensate drift accumulated during outages in receiving GPS signals. Experimental validation on datasets and in a real-world experiment demonstrates the robustness of our approach to GPS dropouts as well as its capability to estimate highly accurate and globally consistent trajectories compared to existing state-of-the-art methods. Simon Boche, Xingxing Zuo 0001, Simon Schaefer, Stefan Leutenegger |
IROS | 3 |
| 2021 | Leveraging Neural Network Gradients within Trajectory Optimization for Proactive Human-Robot InteractionsabstractTo achieve seamless human-robot interactions, robots need to intimately reason about complex interaction dynamics and future human behaviors within their motion planning process. However, there is a disconnect between state-of-the-art neural network-based human behavior models and robot motion planners—either the behavior models are limited in their consideration of downstream planning or a simplified behavior model is used to ensure tractability of the planning problem. In this work, we present a framework that fuses together the interpretability and flexibility of trajectory optimization (TO) with the predictive power of state-of-the-art human trajectory prediction models. In particular, we leverage gradient information from data-driven prediction models to explicitly reason about human-robot interaction dynamics within a gradient-based TO problem. We demonstrate the efficacy of our approach in a multi-agent scenario whereby a robot is required to safely and efficiently navigate through a crowd of up to ten pedestrians. We compare against a variety of planning methods, and show that by explicitly accounting for interaction dynamics within the planner, our method offers safer and more efficient behaviors, even yielding proactive and nuanced behaviors such as waiting for a pedestrian to pass before moving. Simon Schaefer, Karen Leung, Boris Ivanovic, Marco Pavone 0001 |
ICRA | 1 |