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Inertial Magnetic SLAM Systems Using Low-Cost Sensors

Huang, Chuan, Hendeby, Gustaf, Skog, Isaac

arXiv.org Artificial Intelligence

Spatially inhomogeneous magnetic fields offer a valuable, non-visual information source for positioning. Among systems leveraging this, magnetic field-based simultaneous localization and mapping (SLAM) systems are particularly attractive because they can provide positioning information and build a magnetic field map on the fly. Moreover, they have bounded error within mapped regions. However, state-of-the-art methods typically require low-drift odometry data provided by visual odometry or a wheel encoder, etc. This is because these systems need to minimize/reduce positioning errors while exploring, which happens when they are in unmapped regions. To address these limitations, this work proposes a loosely coupled and a tightly coupled inertial magnetic SLAM (IM-SLAM) system. The proposed systems use commonly available low-cost sensors: an inertial measurement unit (IMU), a magnetometer array, and a barometer. The use of non-visual data provides a significant advantage over visual-based systems, making it robust to low-visibility conditions. Both systems employ state-space representations, and magnetic field models on different scales. The difference lies in how they use a local and global magnetic field model. The loosely coupled system uses these models separately in two state-space models, while the tightly coupled system integrates them into one state-space model. Experiment results show that the tightly coupled IM-SLAM system achieves lower positioning errors than the loosely coupled system in most scenarios, with typical errors on the order of meters per 100 meters traveled. These results demonstrate the feasiblity of developing a full 3D IM-SLAM systems using low-cost sensors and the potential of applying these systems in emergency response scenarios such as mine/fire rescue.


CzechLynx: A Dataset for Individual Identification and Pose Estimation of the Eurasian Lynx

Picek, Lukas, Belotti, Elisa, Bojda, Michal, Bufka, Ludek, Cermak, Vojtech, Dula, Martin, Dvorak, Rostislav, Hrdy, Luboslav, Jirik, Miroslav, Kocourek, Vaclav, Krausova, Josefa, Labuda, Jirı, Straka, Jakub, Toman, Ludek, Trulık, Vlado, Vana, Martin, Kutal, Miroslav

arXiv.org Artificial Intelligence

We introduce CzechLynx, the first large-scale, open-access dataset for individual identification, pose estimation, and instance segmentation of the Eurasian lynx (Lynx lynx). CzechLynx contains 39,760 camera trap images annotated with segmentation masks, identity labels, and 20-point skeletons and covers 319 unique individuals across 15 years of systematic monitoring in two geographically distinct regions: southwest Bohemia and the Western Carpathians. In addition to the real camera trap data, we provide a large complementary set of photorealistic synthetic images and a Unity-based generation pipeline with diffusion-based text-to-texture modeling, capable of producing arbitrarily large amounts of synthetic data spanning diverse environments, poses, and coat-pattern variations. To enable systematic testing across realistic ecological scenarios, we define three complementary evaluation protocols: (i) geo-aware, (ii) time-aware open-set, and (iii) time-aware closed-set, covering cross-regional and long-term monitoring settings. With the provided resources, CzechLynx offers a unique, flexible benchmark for robust evaluation of computer vision and machine learning models across realistic ecological scenarios.


Findings of the Fourth Shared Task on Multilingual Coreference Resolution: Can LLMs Dethrone Traditional Approaches?

Novák, Michal, Konopík, Miloslav, Nedoluzhko, Anna, Popel, Martin, Pražák, Ondřej, Sido, Jakub, Straka, Milan, Žabokrtský, Zdeněk, Zeman, Daniel

arXiv.org Artificial Intelligence

The paper presents an overview of the fourth edition of the Shared Task on Multilingual Coreference Resolution, organized as part of the CODI-CRAC 2025 workshop. As in the previous editions, participants were challenged to develop systems that identify mentions and cluster them according to identity coreference. A key innovation of this year's task was the introduction of a dedicated Large Language Model (LLM) track, featuring a simplified plaintext format designed to be more suitable for LLMs than the original CoNLL-U representation. The task also expanded its coverage with three new datasets in two additional languages, using version 1.3 of CorefUD - a harmonized multilingual collection of 22 datasets in 17 languages. In total, nine systems participated, including four LLM-based approaches (two fine-tuned and two using few-shot adaptation). While traditional systems still kept the lead, LLMs showed clear potential, suggesting they may soon challenge established approaches in future editions.


Words That Make Language Models Perceive

Wang, Sophie L., Isola, Phillip, Cheung, Brian

arXiv.org Artificial Intelligence

Large language models (LLMs) trained purely on text ostensibly lack any direct perceptual experience, yet their internal representations are implicitly shaped by multimodal regularities encoded in language. We test the hypothesis that explicit sensory prompting can surface this latent structure, bringing a text-only LLM into closer representational alignment with specialist vision and audio encoders. When a sensory prompt tells the model to 'see' or 'hear', it cues the model to resolve its next-token predictions as if they were conditioned on latent visual or auditory evidence that is never actually supplied. Our findings reveal that lightweight prompt engineering can reliably activate modality-appropriate representations in purely text-trained LLMs.


Vibration Damping in Underactuated Cable-suspended Artwork -- Flying Belt Motion Control

Goubej, Martin, Clarke, Lauria, Hrabačka, Martin, Tolar, David

arXiv.org Artificial Intelligence

This paper presents a comprehensive refurbishment of the interactive robotic art installation Standards and Double Standards by Rafael Lozano-Hemmer. The installation features an array of belts suspended from the ceiling, each actuated by stepper motors and dynamically oriented by a vision-based tracking system that follows the movements of exhibition visitors. The original system was limited by oscillatory dynamics, resulting in torsional and pendulum-like vibrations that constrained rotational speed and reduced interactive responsiveness. To address these challenges, the refurbishment involved significant upgrades to both hardware and motion control algorithms. A detailed mathematical model of the flying belt system was developed to accurately capture its dynamic behavior, providing a foundation for advanced control design. An input shaping method, formulated as a convex optimization problem, was implemented to effectively suppress vibrations, enabling smoother and faster belt movements. Experimental results demonstrate substantial improvements in system performance and audience interaction. This work exemplifies the integration of robotics, control engineering, and interactive art, offering new solutions to technical challenges in real-time motion control and vibration damping for large-scale kinetic installations.


Findings of the Third Shared Task on Multilingual Coreference Resolution

Novák, Michal, Dohnalová, Barbora, Konopík, Miloslav, Nedoluzhko, Anna, Popel, Martin, Pražák, Ondřej, Sido, Jakub, Straka, Milan, Žabokrtský, Zdeněk, Zeman, Daniel

arXiv.org Artificial Intelligence

The paper presents an overview of the third edition of the shared task on multilingual coreference resolution, held as part of the CRAC 2024 workshop. Similarly to the previous two editions, the participants were challenged to develop systems capable of identifying mentions and clustering them based on identity coreference. This year's edition took another step towards real-world application by not providing participants with gold slots for zero anaphora, increasing the task's complexity and realism. In addition, the shared task was expanded to include a more diverse set of languages, with a particular focus on historical languages. The training and evaluation data were drawn from version 1.2 of the multilingual collection of harmonized coreference resources CorefUD, encompassing 21 datasets across 15 languages. 6 systems competed in this shared task.


MALPOLON: A Framework for Deep Species Distribution Modeling

Larcher, Theo, Picek, Lukas, Deneu, Benjamin, Lorieul, Titouan, Servajean, Maximilien, Joly, Alexis

arXiv.org Artificial Intelligence

This paper describes a deep-SDM framework, MALPOLON. Written in Python and built upon the PyTorch library, this framework aims to facilitate training and inferences of deep species distribution models (deep-SDM) and sharing for users with only general Python language skills (e.g., modeling ecologists) who are interested in testing deep learning approaches to build new SDMs. More advanced users can also benefit from the framework's modularity to run more specific experiments by overriding existing classes while taking advantage of press-button examples to train neural networks on multiple classification tasks using custom or provided raw and pre-processed datasets. The framework is open-sourced on GitHub and PyPi along with extensive documentation and examples of use in various scenarios. MALPOLON offers straightforward installation, YAML-based configuration, parallel computing, multi-GPU utilization, baseline and foundational models for benchmarking, and extensive tutorials/documentation, aiming to enhance accessibility and performance scalability for ecologists and researchers.


UAV Trajectory Planning with Path Processing

Bouček, Zdeněk, Flídr, Miroslav, Straka, Ondřej

arXiv.org Artificial Intelligence

This paper examines the influence of initial guesses on trajectory planning for Unmanned Aerial Vehicles (UAVs) formulated in terms of Optimal Control Problem (OCP). The OCP is solved numerically using the Pseudospectral collocation method. Our approach leverages a path identified through Lazy Theta* and incorporates known constraints and a model of the UAV's behavior for the initial guess. Our findings indicate that a suitable initial guess has a beneficial influence on the planned trajectory. They also suggest promising directions for future research.


Mission Planner for UAV Battery Replacement

Bouček, Zdeněk, Flídr, Miroslav, Straka, Ondřej

arXiv.org Artificial Intelligence

In contrast to techniques such as Mixed-Integer Linear The ability to deploy and operate multiple unmanned aerial Programming (MILP) [14] or other optimization methods that vehicles (UAVs) simultaneously for extended periods is highly plan the overall mission, our approach leverages the wellknown advantageous in a variety of applications, including surveillance, A* algorithm [15] to efficiently find the optimal times search and rescue, and environmental monitoring [1], for battery replacements, considering the UAVs' current states [2]. However, the management of a swarm of UAVs presents and mission progress.


Findings of the Shared Task on Multilingual Coreference Resolution

Žabokrtský, Zdeněk, Konopík, Miloslav, Nedoluzhko, Anna, Novák, Michal, Ogrodniczuk, Maciej, Popel, Martin, Pražák, Ondřej, Sido, Jakub, Zeman, Daniel, Zhu, Yilun

arXiv.org Artificial Intelligence

This paper presents an overview of the shared task on multilingual coreference resolution associated with the CRAC 2022 workshop. Shared task participants were supposed to develop trainable systems capable of identifying mentions and clustering them according to identity coreference. The public edition of CorefUD 1.0, which contains 13 datasets for 10 languages, was used as the source of training and evaluation data. The CoNLL score used in previous coreference-oriented shared tasks was used as the main evaluation metric. There were 8 coreference prediction systems submitted by 5 participating teams; in addition, there was a competitive Transformer-based baseline system provided by the organizers at the beginning of the shared task. The winner system outperformed the baseline by 12 percentage points (in terms of the CoNLL scores averaged across all datasets for individual languages).