Csaba Hajdu

35278066400

Publications - 25

Mobile Robot Environment Representation Through Fuzzy Signatures-Integrated Quadtrees

Csaba Hajdu Ahmet Mehmet Karadeniz L. T. Koczy

Publication Name: Romanian Journal of Information Science and Technology

Publication Date: 2025-01-01

Volume: 28

Issue: 1

Page Range: 103-116

Description:

This paper presents an innovative environment representation technique for mobile robots, incorporating obstacle detection within their operational space. Leveraging the fuzzy signature method, this approach uses quadtrees for efficient data organization. A set of fuzzy rules evaluates feature points to ascertain the relevance of identified obstacles. These points and their fuzzy associations are systematically arranged using a quadtree structure. The environmental model is reconstructed by traversing this tree and applying the established fuzzy rules. This paper has achieved a high-resolution grid representation of 0.1m within a 20m×20m area. Notably, the inference operation completes in just 0.5 ms, underscoring the method’s efficiency. Additionally, the technique is optimized for low memory consumption, demonstrating effective resource management even on older PCs, such as an Intel Core Duo 2 with 16 GB RAM. This representation is designed to support advanced robotic functions, such as obstacle navigation in a distributed computing environment.

Open Access: Yes

DOI: 10.59277/ROMJIST.2025.1.09

Synergies between Fuzzy Signatures and Hypergraphs

Csaba Hajdu Ahmet Mehmet Karadeniz L. T. Koczy

Publication Name: Proceedings of the International Symposium on Applied Machine Intelligence and Informatics Sami

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 495-500

Description:

Fuzzy signatures have demonstrated effectiveness in various knowledge-representation domains, including medical decision-making systems and complex decision-making tasks across numerous fields. Even though the advancements in the field of fuzzy signatures have been substantial, the complete potential for developing a comprehensive graph-theoretical description format for this domain still needs to be fully realized. This paper introduces a novel hypergraph-based method for modeling fuzzy signatures, which offers a structured approach to their representation but also showcases the potential synergy between fuzzy signatures and hypergraphs. The proposed method is designed to improve fuzzy information representation and streamline the aggregation-based decision-making process. Future research is anticipated to extend the applicability of this method to control systems and robotics. Furthermore, the hypergraph-based model opens new avenues for the algebraic analysis of fuzzy signatures through tensor-based representations.

Open Access: Yes

DOI: 10.1109/SAMI63904.2025.10883273

Chatbot assistant based on Large-Language Models for University students

Csaba Hajdu K. Kovács Ami Otsuka

Publication Name: Ines 2025 29th IEEE International Conference on Intelligent Engineering Systems 2025 Proceedings

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 77-82

Description:

Large-language models (LLMs) have recently gained significant traction in natural language processing (NLP) by accurately modeling and imitating human-like conversations. One standout application area involves chatbots, which leverage LLMs to provide context-aware, natural language interactions. However, existing solutions often target English and rely on external cloud-based platforms, raising concerns about data privacy and language coverage. In contrast, this paper presents a locally deployable, Hungarian-language chatbot developed to assist university students with education and examination regulations. The proposed system ensures in-house deployment, facilitating compliance with institutional data policies and offering cost-effective scalability. Beyond offering straightforward answers on deadlines and academic rules, our chatbot is designed to handle more nuanced student inquiries, enhancing user experience and administrative efficiency. Preliminary testing demonstrates robust performance in Hungarian context. Future plans include extending the chatbot's domain to more complex subjects, broader document sets, and additional institutions, as well as integrating high-performance computing resources for large-scale deployments.

Open Access: Yes

DOI: 10.1109/INES67149.2025.11078205

Comparison of different geometry trees in fire simulation

L. Környei Csaba Hajdu F. Hajdu Rajmund Kuti Dóra Beke

Publication Name: Pollack Periodica

Publication Date: 2024-10-16

Volume: 19

Issue: 3

Page Range: 34-39

Description:

Wildfire simulations can help to better understand the dynamics and effects of forest fires. The basis of wildfire simulation is the tree-burning simulation. In this paper, the fire simulation of 7 different geometry Hungarian trees in the case of arson is presented. It was observed that the trees were burned down fast. The maximum mass loss rate and maximum heat release rate were larger as the tree was larger. The largest intensity fire could be observed in the case of the smallest tree. The maximum temperature was higher in the case of a large crown diameter. The maximum aerosol reached high pollutant concentrations. In the case of large crown height, the maximum CO2 concentration was higher. The results presented in this paper can be the basis of the following forest fire simulations.

Open Access: Yes

DOI: 10.1556/606.2024.01022

Defining User Coordinate Systems for Industrial Robots in Mixed Reality

Péter Galambos Csaba Hajdu Károly Széll Zoltán Szilágyi Ákos Soós

Publication Name: Cando EPE 2024 Proceedings IEEE 7th International Conference and Workshop Obuda on Electrical and Power Engineering

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 225-230

Description:

This article presents a solution to support the identification of important user coordinate systems for creating an industrial robot work programme. The objective of this article is to provide a support tool for users for a task that may arise numerous times during the lifecycle of industrial robots. The solution described in the article offers a developable support tool that can be transferred from the industrial robotics environment to the collaborative robots' application environment, where the proportion of professionally trained and experienced users may be smaller compared to the previously mentioned area. By reducing the time required and improving the quality of task results, it can contribute to increasing the efficiency of robot systems.

Open Access: Yes

DOI: 10.1109/CANDO-EPE65072.2024.10772842

Hypergraph-based Modeling of Cognitive Dataflow Systems

Aádám Csapó Csaba Hajdu

Publication Name: 2024 IEEE 15th International Conference on Cognitive Infocommunications Coginfocom 2024

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 37-42

Description:

Cognitive systems have become widespread in various computer-based applications, from assistants to robotic systems. Although such systems are useful even in their current version, there is a growing need to incorporate semantic information. This paper introduces HyMeKo, a framework for modeling information using hypergraphs, which allows for the creation of multiple relationships between information entities through a LALR(1)-based language. The framework’s primary application contexts are in robotics, cyber-physical systems, and intelligent systems. A key innovation of this work is a transformation method between hypergraph semantic descriptions and e-adjacency tensors. An additional practical result from the implementation of the framework is a hypergraph-based dataflow system, enabling the simultaneous description and execution of dataflow processes. The paper includes a minimal example to compare the compactness of the introduced language with the widespread URDF, to describe a minimal, 2-link system, demonstrating its advantages in terms of conciseness and flexibility.

Open Access: Yes

DOI: 10.1109/CogInfoCom63007.2024.10894728

Calibration Measurements and Computational Models of Sensors Used in Autonomous Vehicles

Csaba Hajdu István Lakatos

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2023-01-01

Volume: 51

Issue: 3

Page Range: 230-241

Description:

An increasing number of vehicles are equipped with cameras. As perception sensors, they scan the surrounding area and supply the Advanced Driver Assistance Systems (ADAS) for building up an environmental model through the use of computer vision techniques. While they perform well under good weather conditions their efficiency is reduced by adverse environmental influences such as rain, fog and occlusion through dirt. As a consequence, the vision based ADAS obtains poor quality information, and the model also becomes faulty. This paper deals with methods to estimate information quality of cameras in order to warn the assistance system of possible wrong working conditions. In particular, situations of contamination or occlusion of the windshield or camera lens, as well as foggy weather are taken into account in this paper. In the issue of occlusion total, fractional and transparent effectuations have to be recognized and distinguished. Therefore, this paper proposes an approach based on edge analysis of consecutive frames and presents initial experimental results of the implementation. In the field of Fog Detection a method based on the Logarithmic Image Processing Model is described and the results are shown.

Open Access: Yes

DOI: 10.3311/PPtr.18453

Numerical Examination of a Forest Area Fire

L. Környei Csaba Hajdu F. Hajdu Rajmund Kuti Dóra Beke

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 61-66

Description:

An important task of sustainability is the protection of Earth's forests and the prevention of forest fires. In this paper, the numerical examination of a typical Hungarian ash forest fire is presented. The connection between sustainability and forest fire simulations is also discussed. For the simulation, a Fire Dynamics Simulator was selected, and a particle-based model was used. The simulation setup, which includes a random location of trees following Poisson distribution, is also explained. Then, the simulation of a 10x10 m area of ash forest is presented. It was found that in case of arson, the fire spreads rapidly among the trees, and there will be a high-intensity fire in which the forest area burns down in 4 min. The mass loss rate, the temperature, and the heat release rate also increased fast (above 50 kg/s, above 2,000 °C and above 800,000 kW). The aerosol concentration reached a high pollutant concentration (1.3x10-6), and the carbon dioxide concentration also increased significantly (above 14,000 ppm). These changes have a direct effect on climate change. Therefore, it is important to examine them in a simulation environment. The simulation was compared to a pine tree forest simulation, and it could be observed that in the case of the pine tree, the values are similar, but phenomena occur faster. With the computer simulation, it is easier to determine the areas affected by the fire, which also helps fire prevention and firefighting. The aim of the research is to contribute to the prevention and more efficient extinguishment of wildfires and the sustainability of the Earth.

Open Access: Yes

DOI: 10.3303/CET23107011

Examination of effects of indoor fires on building structures and people

L. Környei Csaba Hajdu F. Hajdu Geza Zolyomi Rajmund Kuti Gabriella Lászlo

Publication Name: Heliyon

Publication Date: 2023-01-01

Volume: 9

Issue: 1

Page Range: Unknown

Description:

The scientific study of the harmful effects of indoor fires on building structures and on the environment is a top issue today. Indoor fires frequently occur all over the world. The goal of our research is to examine the effects of an average room fire on the survival possibility of a trapped person and on the building structure, taking into account features of the Eastern European architecture. First, a computational fluid dynamics (CFD) simulation was performed to examine the change of temperature, oxygen, and carbon monoxide concentration in a selected room in a vacant building used for military training. Based on the results, a 1:1 scale fire experiment was carried out with the parameters used in the simulation. The experiment was repeated once with the same settings. It was observed that without the intervention of firefighters, the temperature in the experiment could have rapidly reached 400 °C, as suggested by the simulation, which could have caused structural damage to the building. Furthermore, after 3 min the carbon monoxide concentration reached 400 ppm in both experiments and the simulation, which is a harmful level to people trapped inside the room. Also, in the experiment there was sufficient oxygen at the ground level with what people can survive 3 min.

Open Access: Yes

DOI: 10.1016/j.heliyon.2022.e12720

Analysis of Human-Robot Interactions as a Sustainability Factor

Aádám Csapó Csaba Hajdu

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 85-90

Description:

Robotic systems are traditionally widespread in the efficient automatization of industrial processes. Recent applications include material handling, reconnaissance, and agricultural tasks, besides the more traditional assembly line tasks. On the other hand, the recent advancements of robotic systems aim at enhancing and even replacing the human workforce in traditional social service tasks, like nursery, clerk positions, eldercare, and catering – collectively called social robotics. Developed countries generally suffer from the decreased available workforce in these areas, threatening the long-term availability of such essential services. The robots providing such services are required to appear and behave human-like to some degree to interact with people seamlessly. Human-like behavior requires complex software and hardware systems with learning capabilities to solve social situations appropriately. This paper investigates the relationship between human-robot interactions and sustainability and identifies the foundational similarities between the aims of the two interdisciplinary fields. The paper proposes the effect of complex interaction capabilities on sustainable factors and their possible qualitative verification. The quantitative factors described in this paper are the social perception of different robots and their expected functions defined by the foundational human-robot interaction roles. The paper proposes the possible contribution of future social robot applications to sustainability factors, such as the effect of telepresence. The paper also presents the result of a qualitative survey of participating university students on the acceptance of different types of robots based on their visual appearance. The assumption of possible integration of robots into social roles and what appearance is perceived as acceptable. In summary, this paper highlights the sustainable factors in human-robot interactions by identifying the effects of social robot roles and mapping between corresponsive sustainability factors, most importantly resolving workforce deficit.

Open Access: Yes

DOI: 10.3303/CET23107015

Sustainability Indicators in Industrial Robotic Systems

Péter Galambos Aádám Csapó Csaba Hajdu Károly Széll Zoltán Szilágyi

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 79-84

Description:

Nowadays, the application of industrial robots in manufacturing is widespread to automatize tedious and repeatable precision-sensitive processes. Modern robotic cells compete with the human workforce and specialized industrial machines in general efficiency. Additionally, robotic cells can be typically reprogrammed for different tasks, thus providing flexible applications, especially compared to more traditional methods. Advanced autonomous and intelligent capabilities are widespread in modern robotic systems, supplying quantitative factors like higher availability, fault tolerance, precision, and system flexibility. Robotic systems typically work measurably more efficiently regarding resource usage, electrical power, and waste than other industrial production line systems. New intelligent and interconnected methods (e.g., cooperative robotics, big data analysis, cyber-physical systems) contribute further to the operation efficiency. Recently, sustainability has become a significant question in robotics: modern technical society faces problems such as decreasing availability of natural resources, workforce scarcity, and environmental challenges. This work focuses on industrial robotic systems as a primary pillar for sustainability efforts in numerous production sectors, such as metallurgy, assembly lines, and construction. This paper aims to review and analyze possible sustainability indicators of the industrial applications of robotics. Based on the analysis, the paper presents a manufacturing process model with industrial robots that considers sustainability indicators. This model highlights the relationship between industrial robotization and sustainability from a quantitative and qualitative perspective. The model indicates that energy efficiency and data interconnectivity play a crucial role in the sustainability of industrial processes. The aim of the model is to help identify indicators playing a role in the sustainability of industrial robot-based manufacturing lifecycle and maintenance.

Open Access: Yes

DOI: 10.3303/CET23107014

Defining Synergies Between Robotics, Cognitive Infocommunications and Internet of Digital Reality

Aádám Csapó Csaba Hajdu

Publication Name: 2022 IEEE 1st International Conference on Internet of Digital Reality Iod 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 75-82

Description:

Robotic applications have prominently emerged in automating a wide range of high-precision tasks in industry, logistics, health and military applications. More recently, applications focused on socio-cultural contexts, such as caretaking and personal assistance, have begun to gain traction. In parallel, earlier focus on mechanical and mathematical/control solutions has visibly shifted toward aspects of intelligent and collaborative functions. These changes have brought various aspects of the fields of cognitive infocommunications (CogInfoCom) and Internet of Digital Reality (IoD) to the forefront, both in terms of design methodologies and application areas. While CogInfoCom places emphasis on new kinds of cognitive capabilities / entities that are neither purely human, nor purely artificial, IoD highlights the integration of such capabilities and entities in networked settings created to support specific semantic contexts. Importantly, the scope of such capabilities and/or entities is not limited only to intelligent agents and collaborating humans but also to less capable agents (e.g., cyber-physical and industrial control devices). In a socio-cultural context, the interaction between a robot and other agents (particularly a human) can be viewed as the communication of cognitive entities through some form of Cognitive Infocommunication channels. This paper proposes a new way to view the communication between intelligent robots and cognitive entities.

Open Access: Yes

DOI: 10.1109/IoD55468.2022.9986775

Digital Twin of Drone-based Protection of Agricultural Areas

Á Ballagi Csaba Hajdu A. J. Kovács János Hollósi Gergely Teschner Norbert Boros

Publication Name: 2022 IEEE 1st International Conference on Internet of Digital Reality Iod 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 99-104

Description:

Protecting agricultural fields, like crops, vineyards, and husbandry areas, has been a difficult challenge since historical times. Classical methods to prevent intrusion are often destructive to wild and domestic animals alike. Even more current nondestructive systems, like camera-based systems are attributed to specific problems related to environmental or technological issues. Furthermore, verifying the effectiveness of installed systems is difficult, as the triggering situations are unmanageable and typically occur unsupervised. This paper presents a complex vision-based intrusion detection system to overcome these problems and further proposes more extensive control and flexibility on the development process. The solution provides a workflow integrating Digital Reality methods into the system development by creating a digital twin of the drone and its surrounding environment in a general-purpose robotic simulator. With this simulation, the triggering events and environmental effects can be easily emulated, such as a wild animal entering the area of interest. The solution also focuses on incorporating new 5G info-communication networks on handling communication between the intrusion detection system and the base station in a distributed manner.

Open Access: Yes

DOI: 10.1109/IoD55468.2022.9986763

Tensor-based Format for Exchanging Hypergraphs between Cognitive Entities

Aádám Csapó Csaba Hajdu

Publication Name: 2022 IEEE 1st International Conference on Internet of Digital Reality Iod 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 33-38

Description:

Robotic and other intelligent systems have recently gained prominence, integrating a growing number of new functionalities. Since the beginning, the flexible semantic self-recognition of intelligent devices has been a challenge. The traditional solution is to provide a centralized source of semantic descriptions (in parameter servers or external sources). This paper introduces a graph-like binary format for machine-to-machine information exchange to efficiently index and process graph-based data at each endpoint. The exchanged graphs, which are represented as multidimensional tensors, are based on the formal theory of hypergraphs, allowing for the description of associations between not just two, but multiple modalities. We show in addition that hierarchical information is also compatible with this hypergraph-based formalism. Thus, structured information can be shared between intelligent entities, using the proposed format, to share information for reasoning, planning (e.g., motion planning in robotics), as well as environment representation. A further motivation includes the description of vision data by providing semantic information that can be rewritten in interpretable form for the target visualization engine.

Open Access: Yes

DOI: 10.1109/IoD55468.2022.9986845

Robot environment representation based on Quadtree organization of Fuzzy Signatures

Á Ballagi Csaba Hajdu Ahmet Mehmet Karadeniz L. T. Koczy

Publication Name: Saci 2021 IEEE 15th International Symposium on Applied Computational Intelligence and Informatics Proceedings

Publication Date: 2021-05-19

Volume: Unknown

Issue: Unknown

Page Range: 509-514

Description:

This paper presents a novel approach to mobile robot environment representation to hold information on detected obstacles. The method is inspired by fuzzy signature-based formalism and is based on classical quadtrees as a data indexing structure. Each detected feature point is evaluated by a fuzzy-ruleset defining the presumed significance of each detected object. Feature points and their fuzzy-mapping are indexed in a classical quadtree-based fashion. During the reconstruction of the environment representation, inference is done by the traversal on the constructed tree using accumulated fuzzy-ruleset. Our goal is to use this representation format for further robotic tasks such as obstacle avoidance in a distributed computational environment.

Open Access: Yes

DOI: 10.1109/SACI51354.2021.9465566

Possible Control Methods for Skid-Steer Mobile Robot Platforms

Á Ballagi Csaba Hajdu Rudolf Krecht

Publication Name: Gpmc 2020 2nd IEEE International Conference on Gridding and Polytope Based Modeling and Control Proceedings

Publication Date: 2020-11-19

Volume: Unknown

Issue: Unknown

Page Range: 31-34

Description:

The aim of this paper is to collect and analyze the possible low-level control methods for skid-steer mobile robot platforms. Most low-level control methods for mobile robots rely on the kinematic or dynamic model of the controlled robot platform. However, in case of skid-steer mobile robots, a precise kinematic or dynamic model might be too costly to be implemented for a control method. Thus, it has an outstanding importance to find a control method which can be precise enough even with a simplified kinematic or dynamic model. The overall control scheme of skid-steer robots is also discussed, along with issues regarding the kinematic and dynamic modelling of the mentioned platforms.

Open Access: Yes

DOI: 10.1109/GPMC50267.2020.9333814

Towards a quadtree based approach to learn local plans in robotic motion planning

Á Ballagi Csaba Hajdu

Publication Name: Gpmc 2020 2nd IEEE International Conference on Gridding and Polytope Based Modeling and Control Proceedings

Publication Date: 2020-11-19

Volume: Unknown

Issue: Unknown

Page Range: 25-30

Description:

In this paper, a novel approach to the local planning of mobile robots and autonomous vehicles is discussed. This paper introduces a motion planning architecture utilizing both a conventional (Hybrid A∗) and a learning-based planner, inspired by the recent results of reinforcement learning. The presented approach relies on a grid-based representation of the environment which is simultaneously used for planning and learning of such trajectories. The representation grid is derived from a quadtree representation of the environment and the definition is extended with convex polytopic description, to produce grid-based and Voronoi diagrams. The paper also discusses the possible integration of more sophisticated soft-computing-based control, like TP-model transformation as a basis for the heuristics used by motion planning components.

Open Access: Yes

DOI: 10.1109/GPMC50267.2020.9333811

Fuzzy logic based sensitivity study of nonlinear systems

Csaba Hajdu F. Hajdu

Publication Name: Gpmc 2020 2nd IEEE International Conference on Gridding and Polytope Based Modeling and Control Proceedings

Publication Date: 2020-11-19

Volume: Unknown

Issue: Unknown

Page Range: 19-24

Description:

A fuzzy logic based One-at-a-Time sensitivity study method of nonlinear systems is proposed in this paper. The advantage of the method is that it can be used for a wider parameter examination range. With the use of fuzzy logic a smooth evaluation of sensitivity study could be achieved and the degree of sensitivity of parameters could be easily compared. The method was tested with 2 case studies: The sensitivity study of a nonlinear Duffing-type vibration system and a vehicle simulation using an open-source physics simulator. With the simulation results it was shown that the method can be used effectively for sensitivity study of nonlinear systems in an extended examination range.

Open Access: Yes

DOI: 10.1109/GPMC50267.2020.9333818

Economical Mobile Robot Design Prototype and Simulation for Industry 4.0 Applications

R. C. Pozna Á Ballagi Csaba Hajdu János Hollósi Rudolf Krecht

Publication Name: Cando EPE 2020 Proceedings IEEE 3rd International Conference and Workshop in Obuda on Electrical and Power Engineering

Publication Date: 2020-11-18

Volume: Unknown

Issue: Unknown

Page Range: 155-160

Description:

Autonomous mobile robots received a rising research interest, with the appearance of complex cyber-physical system applications, like Industry 4.0. Related scenarios require not only some degree of autonomous capabilities of the control software but also tight interaction between humans as well. In this paper, a prototype autonomous mobile robot of such functionalities is presented with additionally aiming cost-effective construction. The robot is currently capable of performing basic tasks, like traversing to a goal configuration, mapping the environment, and detecting and avoiding obstacles. To allow the versatile extension with additional cyber-physical software, the control software interfaces the Robot Operating System (ROS), a popular framework in robotic research. During the development of software and hardware, simulation has been heavily utilized. This allowed an iterative development and the use of verification in the early development phases.

Open Access: Yes

DOI: 10.1109/CANDO-EPE51100.2020.9337786

Proposal of a graph-based motion planner architecture

Á Ballagi Csaba Hajdu

Publication Name: 11th IEEE International Conference on Cognitive Infocommunications Coginfocom 2020 Proceedings

Publication Date: 2020-09-23

Volume: Unknown

Issue: Unknown

Page Range: 393-398

Description:

Motion planning is a critical task in robots and autonomous vehicles. This task is typically complex in computation and structure. Current frameworks are difficult to extend and supervise. This article presents a new architectural proposal of motion planning software, which can be used by mobile robots and autonomous vehicles. Defining aspects have been inspired by the foundations of Cognitive Infocommunications (CogInfoCom) to construct a highly interactive system aiming intuitive human-computer collaboration. The structure is based on a graph-based approach which is suitable in a distributed setting. This formalization provides a graphical behavior description, an intuitive way for human actors to interact with the system. The behavior of each acting component is based on a hybrid-system formalism which can further serve as a basis to model human behavior.

Open Access: Yes

DOI: 10.1109/CogInfoCom50765.2020.9237891

Model-oriented control software development of academic autonomous test vehicle

Á Ballagi Csaba Hajdu

Publication Name: Ines 2020 IEEE 24th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2020-07-01

Volume: Unknown

Issue: Unknown

Page Range: 73-78

Description:

This paper presents a model-oriented toolset developed for academic autonomous vehicle projects. Typical parameters are modeled into a structured domain model, which provides an organized view of the target vehicle. This model can be used to generate the bridge software linking low-level control software (e.g. CAN network) with high-level middleware frameworks. Other software items can be also originated from this model, including the configuration of deployed sensory components and simulation description. Code generation is performed via transforming the vehicle domain model instance into other specific domains (e.g. general kinematic description from vehicle description). As a result, a tool is provided which can be used to define a vehicle configuration in a textual format. The generators create code interfacing the open-source Robot Operating System (ROS).

Open Access: Yes

DOI: 10.1109/INES49302.2020.9147202

Enhancement of pure-pursuit path-tracking algorithm with multi-goal selection

Csaba Hajdu Ernö Horváth Peter Koros

Publication Name: Gpmc 2019 1st IEEE International Conference on Gridding and Polytope Based Modeling and Control Proceedings

Publication Date: 2019-11-01

Volume: Unknown

Issue: Unknown

Page Range: 13-18

Description:

In this paper, we present an enhancement to the popular pure-pursuit algorithm, widely used in robotics and automotive applications. The original algorithm is simple and straightforward as it depends only on the very basic attributes of the kinematic model of the target mechanical system. The algorithm is usually tuned by choosing a look-ahead distance of points from the reference trajectory. On the other hand, pure-pursuit suffers from considerable tuning weaknesses highly attributed to improper selection of look-ahead distance, resulting in poor tracking performance. Our method proposes the dynamic change of lookahead distance based on selecting multiple-goal points, thus aiming a curvature fitting more the reference trajectory. Our work was motivated by an ongoing robotics and autonomous vehicle research project at our university.

Open Access: Yes

DOI: 10.1109/GPMC48183.2019.9106958

Novel Pure-Pursuit Trajectory Following Approaches and their Practical Applications

Csaba Hajdu Ernö Horváth Peter Koros

Publication Name: 10th IEEE International Conference on Cognitive Infocommunications Coginfocom 2019 Proceedings

Publication Date: 2019-10-01

Volume: Unknown

Issue: Unknown

Page Range: 597-602

Description:

Pure-pursuit algorithm is a popular trajectory tracking algorithm, widely used in mobile robotics and vehicular control for numerous reasons. The operation is simple and straightforward as it depends only on the kinematic model of the target mechanical system. The algorithm can be tuned by choosing look-Ahead distance of points of the reference trajectory. On the other hand, pure-pursuit suffers from weaknesses highly attributed to improper selection of look-Ahead distance, resulting in poor tracking performance. Recent developments focused on overcoming this drawback by dynamical change of this parameter. In this paper, we propose three enhancements to the original pure-pursuit algorithm, aiming to handle dynamic selection of look-Ahead distance by selecting multiple goals, modifying look-Ahead distance according to the curvatures and adjusting lateral deviation. Our work was motivated by an ongoing autonomous vehicle research at our university.

Open Access: Yes

DOI: 10.1109/CogInfoCom47531.2019.9089927

Range sensor-based occupancy grid mapping with signatures

Á Ballagi Csaba Hajdu Ernö Horváth Claudiu Radu

Publication Name: Proceedings of the 2019 20th International Carpathian Control Conference Iccc 2019

Publication Date: 2019-05-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Recently autonomous navigation technologies have received huge attention in many fields, such as autonomous driving or mobile robotics. Simultaneous localization and mapping (SLAM) [1] is a key problem in this field and the current paper targets the mapping part of it. Mapping means to construct accurate static or even dynamic representation of the observable environment. There are of course solutions for range sensor-based mapping, but the current paper proposes a new approach, which involves signatures. Signature is a mathematical data representation, which handles well uncertainty in complex systems.

Open Access: Yes

DOI: 10.1109/CarpathianCC.2019.8765684

Generative Hypergraph-based Kinematic Models for Virtual-Reality Applications

Aádám Csapó Csaba Hajdu

Publication Name: 2022 1st IEEE International Conference on Cognitive Aspects of Virtual Reality Cvr 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 11-16

Description:

Recently, virtual reality applications have become a prominent research area, along with related topics such as digital-twin applications and simulation of devices such as vehicles or cyber-physical systems. These topics are intimately linked with computer-based simulations and computer graphics. Consequently, accurately describing entities populating simulated worlds is a critical task. Relevant properties include but are not limited to an object's visual appearance and kinematic constraints. This paper proposes a hypergraph-based kinematic model aiming to describe virtual entities used in virtual reality applications and simulations. Compared to other popular schematics (e.g., URDF, SDF), a primary advantage of this approach is its reduced language element set, which is capable of minimally describing a conceptually very simple kind of hypergraph. This reduction, in turn, enables the description of simple graph triplets amenable to storage in graph databases or ontologies. The introduced format is aimed at enabling the flexible and efficient real-time exchange of visual and physical information on cognitive channels between entities. The possibility of transforming an instance of this model into other schematics (SDF, MaxWhere) is further demonstrated in the paper, which constructively proves the expressive capabilities of the model and helps support the claim that it is equivalent in expressive power to other widely used description models.

Open Access: Yes

DOI: 10.1109/CVR55417.2022.9967632