Martin Varga

Dr. Martin Varga

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 February 2024 in Sensors
Verified
Journal Article
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Peter Jan SincakPeter Jan Sincak
Peter Jan Sincak
Erik PradaErik Prada
Erik Prada
ĽMĽubica Miková
Ľubica Miková
Roman MykhailyshynRoman Mykhailyshyn
Roman Mykhailyshyn
MVMartin Varga
Martin Varga
Ivan VirgalaIvan Virgala
Ivan Virgala
The field of continuum robotics is rapidly developing. The development of new kinematic structures, locomotion principles and control strategies is driving the development of new types of sensors and sensing methodologies. The sensing in continuum robots can be divided into shape perception and environment perception. The environment perception is focusing on sensing the interactions between the robot and environment. These sensors are often embedded on an outer layer of the robots, so the interactions can be detected. The shape perception is sensing the robot’s shape using various principles. There are three main groups of sensors that use the properties of electricity, magnetism and optics to measure the shape of the continuum robots. The sensors based on measuring the properties of electricity are often based on measuring the electrical resistance or capacitance of the flexible sensor. Sensors based on magnetism use properties of permanent magnets or coils that are attached to the robot. Their magnetic field, flux or other properties are then tracked, and shape reconstruction can be performed. The last group of sensors is mostly based on leveraging the properties of traveling light through optical fibers. There are multiple objectives of this work. Objective number one is to clearly categorize the sensors and make a clear distinction between them. Objective number two is to determine the trend and progress of the sensors used in continuum robotics. And finally, the third objective is to define the challenges that the researchers are currently facing. The challenges of sensing the shape or the interaction with the environment of continuum robots are currently in the miniaturization of existing sensors and the development of novel sensing methods.

3 June 2020 in Symmetry
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Journal Article
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Ivan VirgalaIvan Virgala
Ivan Virgala
MKMichal Kelemen
Michal Kelemen
Pavol BožekPavol Božek
Pavol Božek
ZBZdenko Bobovský
Zdenko Bobovský
MHMartin Hagara
Martin Hagara
MVMartin Varga
Martin Varga
This paper analyzed the locomotion of a snake robot in narrow spaces such as a pipe or channel. We developed a unique experimental snake robot with one revolute and one linear joint on each module, with the ability to perform planar motion. The designed locomotion pattern was simulated in MATLAB R2015b and subsequently verified by the experimental snake robot. The locomotion of the developed snake robot was also experimentally analyzed on dry and viscous surfaces. The paper further describes the investigation of locomotion stability by three symmetrical curves used to anchor static modules between the walls of the pipe. The stability was experimentally analyzed by digital image correlation using a Q-450 Dantec Dynamics high-speed correlation system. The paper presents some input symmetrical elements of locomotion and describes their influence on the results of locomotion. The results of simulations and experiments show possibilities of snake robot locomotion in a pipe.

19 April 2022 in Applied Sciences
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Journal Article
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Ivan VirgalaIvan Virgala
Ivan Virgala
ĽMĽubica Miková
Ľubica Miková
TKTatiana Kelemenová
Tatiana Kelemenová
MVMartin Varga
Martin Varga
RRRóbert Rákay
Róbert Rákay
PTPeter Tuleja
Peter Tuleja
The paper deals with the proposed concept of a biped robot with vertical stabilization of the robot’s base and minimization of its sideways oscillations. This robot uses 6 actuators, which gives good preconditions for energy balance compared to purely articulated bipedal robots. In addition, the used linear actuator is self-locking, so no additional energy is required for braking or to keep it in a stable position. The direct and inverse kinematics problems are solved by means of a kinematic model of the robot. Furthermore, the task is aided by a solution for locomotion on an inclined plane. Special attention is focused on the position of the robot’s center of gravity and its stability in motion. The results of the simulation confirm that the proposed concept meets all expectations. This robot can be used as a mechatronic assistant or as a carrier for handling extensions.

13 October 2021 in MM Science Journal
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Journal Article
Open access
MKMichal Kelemen
Michal Kelemen
TKTatiana Kelemenová
Tatiana Kelemenová
MVMartin Varga
Martin Varga
PSPeter Jan Sincak
Peter Jan Sincak
LLLukas Lestach
Lukas Lestach
ACAlena Alekseevna Chernova
Alena Alekseevna Chernova
Hall effect sensor is a very frequently used sensor in mechatronic products. There is little information in the catalogue sheets about the application possibilities of this type of sensor. This article examines the configuration options of this sensor and how to use it to achieve the best measurement uncertainty and minimal hysteresis.

1 January 2020 in TECHNICAL SCIENCES AND TECHNOLOGIES
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MVMartin Varga
Martin Varga
FFFilip Filakovský
Filip Filakovský
Urgency of the research. Currently, manufacturing of pneumatic components is reserved only to well-equipped manufacturing plants and machine shops. The ability to reliably manufacture pneumatic components on a FDM 3D printer would enable the creation of low-cost custom-made pneumatic actuators with novel properties. This, in turn, could increase the speed and lower the cost of development of prototypes that use pressure air as their power source. Target setting. Today cost-effective 3D printers can be found both in manufacturing plants and small machine shops andhobbyist workshops. Hawing the possibility to make reliable pneumatic components like pneumatic actuators on such machines could be beneficial and lead to opening new applications for them. Actual scientific researches and issues analysis. Currently most research on using additive manufacturing to construct a pneumatic actuator focuses mainly on bellows type actuators. Research on 3d printing of classical pneumatic actuators is scarce and often presents a rough overview of the design process and immediately presenting a functional prototype without focusing and studying the design hurdles thoroughly. Uninvestigated parts of general matters defining. Parts for firm pneumatic actuators manufactured by FDM 3D printing exhibit properties that have detrimental effects on the optimal working of such actuators. The question is on the magnitude of these effects whether these effects can be tolerated and how to design such a firm pneumatic actuator without the need to postprocess all the components. The research objective. The aim of these research was to manufacture an early prototype of full plastic 3d printed not postprocessed linear actuators and make a preliminary analysis of encountered problems therefore pointing the way for further research in this field. The statement of basic materials. The analysis consists of an attempt to manufacture a simple prototype of full plastic 3d printed linear actuators without the use of postprocessing techniques and establishing a baseline for further research. Conclusions. In this paper the design of three iterations of FDM 3D printed pneumatic cylinders are presented. The problems arising from not using any postprocessing on either of the parts and using only 3d printed parts for the construction is also discussed. In the final chapter the design hurdles for the design and manufacturing of such an actuator are presented..

14 December 2023 in Applied Sciences
Verified
Journal Article
Open access
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MVMartin Varga
Martin Varga
Ivan VirgalaIvan Virgala
Ivan Virgala
MKMichal Kelemen
Michal Kelemen
ĽMĽubica Miková
Ľubica Miková
ZBZdenko Bobovský
Zdenko Bobovský
TMTomas Merva
Tomas Merva
Redundant cascade manipulators actuated by pneumatic bellows actuators are passively compliant, rugged and dexterous, making them exceptionally well suited for application in agriculture. Unfortunately, the bellows are notoriously difficult to precisely position. This paper presents a novel control algorithm for the control of a parallel platform actuated by pneumatic bellows, which serves as a module of a cascade manipulator. The algorithm combines a feed-forward controller and a variable-gain I-controller. The mathematical model of the module, which serves as the feed-forward controller, was created by applying two simple regression steps on experimentally acquired data. The gain of the I-controller is linearly dependent on the total reference error, thereby addressing the prevalent problem of “a slow response or excessive overshoot”, which, in the described case, the simple combination of a feed-forward and constant-gain I-controller tends to suffer from. The proposed algorithm was experimentally verified and its performance was compared with two controllers: an ANFIS controller and a constant gain PID controller. The proposed controller has outperformed the PID controller in the three calculated criteria: IAE, ISE and ITAE by more than 40%. The controller was also tested under dynamic loading conditions, showing promising results.