Darius Plonis

Prof. Dr. Darius Plonis

Department of Electronic Systems, Faculty of Electronics, Vilnius Gediminas Technical University-Vilnius Tech, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania
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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

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

Representative Publications

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2 February 2021 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MLMindaugas Luneckas
Mindaugas Luneckas
TLTomas Luneckas
Tomas Luneckas
JKJonas Kriaučiūnas
Jonas Kriaučiūnas
DUDainius Udris
Dainius Udris
Darius PlonisDarius Plonis
Darius Plonis
RMRytis Maskeliūnas
Rytis Maskeliūnas
Due to the prospect of using walking robots in an impassable environment for tracked or wheeled vehicles, walking locomotion is one of the most remarkable accomplishments in robotic history. Walking robots, however, are still being deeply researched and created. Locomotion over irregular terrain and energy consumption are among the major problems. Walking robots require many actuators to cross different terrains, leading to substantial consumption of energy. A robot must be carefully designed to solve this problem, and movement parameters must be correctly chosen. We present a minimization of the hexapod robot’s energy consumption in this paper. Secondly, we investigate the reliance on power consumption in robot movement speed and gaits along with the Cost of Transport (CoT). To perform optimization of the hexapod robot energy consumption, we propose two algorithms. The heuristic algorithm performs gait switching based on the current speed of the robot to ensure minimum energy consumption. The Red Fox Optimization (RFO) algorithm performs a nature-inspired search of robot gait variable space to minimize CoT as a target function. The algorithms are tested to assess the efficiency of the hexapod robot walking through real-life experiments. We show that it is possible to save approximately 7.7–21% by choosing proper gaits at certain speeds. Finally, we demonstrate that our hexapod robot is one of the most energy-efficient hexapods by comparing the CoT values of various walking robots.

12 July 2020 in Electronics
Verified
Journal Article
Open access
PDF file
VAVytautas Abromavicius
Vytautas Abromavicius
Darius PlonisDarius Plonis
Darius Plonis
DTDeividas Tarasevičius
Deividas Tarasevičius
Artūras SerackisArtūras Serackis
Artūras Serackis
The presented research faces the problem of early detection of sepsis for patients in the Intensive Care Unit. The PhysioNet/Computing in Cardiology Challenge 2019 facilitated the development of automated, open-source algorithms for the early detection of sepsis from clinical data. A labeled clinical records dataset for training and verification of the algorithms was provided by the challenge organizers. However, a relatively small number of records with sepsis, supported by Sepsis-3 clinical criteria, led to highly unbalanced dataset (only 2% records with sepsis label). A high number of unbalanced data records is a great challenge for machine learning model training and is not suitable for training classical classifiers. To address these issues, a method taking into the account the amount of time the patients spent in the intensive care unit (ICU) was proposed. The proposed method uses two separate ensemble models, one trained on patient records under 56 h in the ICU, and another for patients who stayed longer than 56 h. A solution including feature selection and weighting based training on imbalanced data was proposed in this paper. In addition, several performance metrics were investigated. Results show, that for successful prediction, a particular model having few or more predictors based on the length of stay in the Intensive Care Unit should be applied.

6 December 2020 in Intelligent Service Robotics
Verified
Journal Article
Open access
PDF file
MLMindaugas Luneckas
Mindaugas Luneckas
TLTomas Luneckas
Tomas Luneckas
DUDainius Udris
Dainius Udris
Darius PlonisDarius Plonis
Darius Plonis
RMRytis Maskeliūnas
Rytis Maskeliūnas
RDRobertas Damaševičius
Robertas Damaševičius
Walking robots are considered as a promising solution for locomotion across irregular or rough terrain. While wheeled or tracked robots require flat surface like roads or driveways, walking robots can adapt to almost any terrain type. However, overcoming diverse terrain obstacles still remains a challenging task even for multi-legged robots with a high number of degrees of freedom. Here, we present a novel method for obstacle overcoming for walking robots based on the use of tactile sensors and generative recurrent neural network for positional error prediction. By using tactile sensors positioned on the front side of the legs, we demonstrate that a robot is able to successfully overcome obstacles close to robots height in the terrains of different complexity. The proposed method can be used by any type of a legged machine and can be considered as a step toward more advanced walking robot locomotion in unstructured terrain and uncertain environment.

17 February 2020 in IEEE Access
Verified
Journal Article
Open access
Darius PlonisDarius Plonis
Darius Plonis
Andrius KatkevičiusAndrius Katkevičius
Andrius Katkevičius
AGAntanas Gurskas
Antanas Gurskas
VUVytautas Urbanavičius
Vytautas Urbanavičius
RMRytis Maskeliūnas
Rytis Maskeliūnas
RDRobertas Damasevicius
Robertas Damasevicius
Meander structures are highly relevant in the Internet-of-Things (IoT) communication systems, their miniaturization remains as one of the key design issues. Meander structures allow to decrease the size of the IoT device, while maintaining the same operating parameters of the IoT device. Meander structures can also work as the delay systems, which can be used for the delay and synchronization of signals in IoT devices. The design procedure of the meander delay systems is time-consuming and cumbersome because of the complexity of the numerical and analytical methods employed during the design process. New methods, which will accelerate the synthesis procedure of the meander delay systems, should be investigated. This is especially relevant when the procedure of synthesis must be repeated many times until the appropriate configuration of the IoT device is found. We present the procedure of synthesis of the meander delay system using the Pareto-optimal multilayer perceptron network and multiple linear regression model with the M5 descriptor. The prediction results are compared with results, which were obtained using the commercial Sonnet© software package and with the results of physical experiment. The difference between the experimentally achieved and predicted results did not exceed 1.53 %. Moreover, the prediction of parameters of the meander delay system allowed to speed up the procedure of synthesis multiple times from hours to only 2.3 s.

11 August 2022 in Electronics
Verified
Journal Article
Open access
PDF file
SRSaulius Rudys
Saulius Rudys
PRPaulius Ragulis
Paulius Ragulis
ALAndrius Laučys
Andrius Laučys
DBDomantas Bručas
Domantas Bručas
RPRaimondas Pomarnacki
Raimondas Pomarnacki
Darius PlonisDarius Plonis
Darius Plonis
The development of unmanned aerial vehicle (UAV) technologies provides not only benefits but also threats. UAV technologies are developing faster than means of detecting and neutralizing them. Radar technology is one of the means of UAV detection which provides the longest detection range. Today’s market provides low-cost solid-state marine radar working on FMCW and pulse-compression principles of operation. Despite such radars having attractive features, they were not designed for UAV detection. Although they are not optimal, they could be used for UAV detection. The detection possibility of UAVs by marine radars was investigated by using three types of radars and two types of small UAVs as targets. Radar cross-section measurements of the targets were made in laboratory conditions.

25 September 2019 in Metrology and Measurement Systems
Verified
Journal Article
Closed access
PDF file
MLMindaugas Luneckas
Mindaugas Luneckas
TLTomas Luneckas
Tomas Luneckas
DUDainius Udris
Dainius Udris
Darius PlonisDarius Plonis
Darius Plonis
RMRytis Maskeliunas
Rytis Maskeliunas
RDRobertas Damasevicius
Robertas Damasevicius