Applied sciences

Bulletin of the Polish Academy of Sciences Technical Sciences

Content

Bulletin of the Polish Academy of Sciences Technical Sciences | Early Access

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Abstract

The distributed fuel cell tractor is a new type of power tractor. The transmission system and control strategy parameters affect the energy utilization efficiency of the entire machine. There is currently no research in this area. In order tosolve the problem of low energy utilization of the whole machine of distributed dual-motor-driven hydrogen fuel cell tractor, a cooperative optimization method based on particle swarm optimization (PSO) algorithm for the parameters of the transmission system and energy-saving control strategy of distributed dual-motor-driven hydrogen fuel cell tractor is proposed. According to the tractor dynamics analysis and equivalent hydrogen consumption theory, a fuel cell tractor transmission parameter-equivalent hydrogen consumption model is established, The wheel-side transmission ratio and the upper and lower threshold values of the hydrogen fuel cell working power are taken as control variables, and the minimum equivalent hydrogen consumption is taken as the optimization goal, the optimization method is simulated and tested based on the MATLAB simulation platform. The results show that under plowing conditions, compared with the rule-based control strategy, the proposed collaborative optimization method of the fuel cell tractor transmission system and control strategy parameters can reasonably control the operating status of the fuel cell and the power battery, ensure that the fuel cell works in a high efficiencyrange, enhance the overall performance of the fuel cell system, and control the power battery state of charge (SOC) to remain in areasonable range. The tractor equivalenthydrogen consumption is reduced by 7.84%.
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Authors and Affiliations

Liyou Xu
Shixun Chen
Junjiang Zhang
Mengnan Liu
Yiwei Wu
Xianghai Yan
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Abstract

The core concept in this paper is to hybridize a conventional engine-powered two-wheeler into a hybrid electric vehicle. The shift in the consumers' mindset from conventional IC Engine vehicles to Electric/hybrid vehicles may be a challenge due to the high initial investment. Hence, as a preliminary work, it is proposed to convert an IC engine vehicle to a hybrid electric vehicle considering factors such as affordability, user control, and flexibility. To make the hybrid vehicle available at an affordable price, lead-acid batteries are used for the study. Also, the BLDC motor used in this vehicle has been designed and developed according to the available design constraints. The moped has been redesigned to operate in either engine or electric mode individually depending on the rider’s desire and can switch over to any mode at any time as intended. This is achieved using a unique switching mechanism constructed using needle roller bearings. The concept of hybridization thus results in reduced emissions, especially in stop-go traffic where electric mode can be used, and the performance of hybrid electric vehicles is estimated.
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Authors and Affiliations

Thenmozhi Ganesan
Chandra Vanaraj
Manoharan Subramanian
Radhika Alagesan
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Abstract

Unmanned aerial vehicles (drones) are increasingly used in a growing number of applications, both civil and military. Their design is based on low weight, making the presence of shielding a difficult decision between safety and weight. Currently, there are no mathematical models to determine the safety of drones operating near a storm front. Lightning causes an electromagnetic wave of an impulse nature, which may pose a real threat to electronic systems. This work attempts to develop a mathematical model for simulating drones safety in terms of electromagnetic pulses using artificial intelligence-based tools. Actual measurement results collected from four drones were used as training data. They were tested in laboratory conditions using specialized measuring equipment used to test avionics in accordance with international standards such as DO-160. A repeatable surge pulse generator and a data acquisition system allowed us to collect information on how overvoltages propagate inside the drone’s systems. Systems that directly influence its operation were selected for this purpose, such as the power supply system, engine controllers, GPS system, camera and data bus lines. Other works show that most overvoltages are induced in motor coils and antennas. On this basis, a number of formulas and equations were developed to describe the most important elements of the drone, without which its correct operation will not be possible. The results of the analyzes and the mathematical model of the drone based on the examined cases are presented in this work as a complement to real experiments.
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Authors and Affiliations

Tomasz Kossowski
Damian Mazur
ORCID: ORCID
Bogdan Kwiatkowski
ORCID: ORCID
Przemysław Hawro
ORCID: ORCID
Andrzej Imiełowski
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Abstract

This paper introduces a new modification to the motion planning algorithm of nonholonomic robotic systems using the Endogenous Configuration Space Approach which allows imposing restrictions on control functions. The end and via points define the values which the control function should take in a predefined time, either at the beginning, the end or during the motion time horizon. Such a modification can be used to set the values of the control function, which usually are of velocity–like type, to be physically realizable. The constraints are introduced to the algorithm through the extension of the Jacobian. The efficiency of the presented method is shown with the computer simulation results for a nonholonomic space manipulator. A modified Jacobian motion planning algorithm is used for planning consisting of a sequence of two subtasks.
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Authors and Affiliations

Joanna Ratajczak
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Abstract

In the wire drawing process, the wire is subjected to sharpening before each drawing. Traditional methods forsharpening wires involve one of the following techniques: crimping, grinding, rolling, chemical etching, or stretching within a furnace. Wire sharpening becomes especially difficult in the manufacture of ultra-thin wire. This study proposes and examines a novel technique for sharpening thin and ultra-thin wires through specialized stretching in a furnace. This study proposes and investigates a new technique for sharpening thin and ultra-thin wires based on stretching them in the furnace. Using a rheology- based concept of wire deformation during stretching, this study offers a substantial enhancement in the maximum attainable thinning of the wire during sharpening. Technically, this advancement is achieved by transitioning from a single-stage stretching process to an incremental one, characterized by small increments of deformation at each stage. In addition to incremental stretching, the proposed method includes simultaneous movement of the wire through a continuous micro furnace, repeated at each stage of elongation. This achieves thinning of the end of the wire of a given length. This study theoretically and experimentally explores further potentialities of this approach concerning the fabrication of ultra-thin wire. The findings show that the effectiveness of the proposed method strongly depends on the shape of the stressstrain curve of the wire material. For example, the conducted research demonstrated that this method is more effective for brass than for copper wire.
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Authors and Affiliations

Piotr Kustra
Andrij Milenin
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Abstract

The article presents the equilibrated residual method (ERM) of error estimation in coupled problems in the case of complex piezoelectric models. These models include hierarchical, first-order and transition models within the mechanical field of displacements, as well as hierarchical models within the electric field of potential. Three (classical, modified and enhanced) transition models are considered. The paper presents a variational formulation of the model problem of general piezoelectricity in the case of complex piezoelectric models and the finite element approximation of this problem. Next, the equilibration residual method for coupled problems of piezoelectricity and complex piezoelectric models is presented. The mechanical, electric and coupled parts of the modelling, approximation and total error estimators and true errors are given. Effectivity indices (the ratio of estimated error to true error) are used to assess the quality of error estimation in the case of three error parts and three types of error for the complex models of piezoelectric plates. The effectivity results for simple piezoelectric models and uncoupled problems of elasticity and dielectricity are applied as references.
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Authors and Affiliations

Magdalena Zielińska
Grzegorz Zboiński
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Abstract

The 5G Enhanced Mobile Broadband (eMBB) category offers faster data rates, network capacity, and user experiences than prior generations. This research aims to boost the 5G uplink User Equipment (UE) user data transfer rate. We use Python to build frameworks and analyze data. A 250-m-radius center-excited Picocell Base Station (PBS) is investigated to support 15 clients. Cell-range Poisson distribution determines user position. All UEs send Channel State Information (CSI) to the PBS, which evaluates signal transmission channel conditions. The study uses Rayleigh, Rician, free space path, and longdistance route loss models. This inquiry produces a channel state dataset and then it is formulated dataset is dynamic. For servicespecific requirements, UEs use K-means clustering. Clustering concatenates bandwidth, enhancing system efficiency and UE sum rate. Observations from simulation findings. UEs are grouped by channel gain, achievable data rate, and minimum servicerequired data rate. Users in cluster 3 achieve the highest cumulative rate of 9.09 Mbps after clustering with an average of 7.16 Mbps. Bandwidth concatenation increased system capacity, meeting each UEs service needs. After evaluating different clustering models performance criteria, K-means remains the best algorithm for the framework. The methodology was carefully designed to satisfy study goals. This research will investigate beamforming and dynamic clustering to improve user fairness and performance.
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Authors and Affiliations

Parameswaran Ramesh
P T V Bhuvaneswari
R S Ashok
S Veena
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Abstract

Autonomous driving is currently a hot topic in automotive engineering. Accurately predicting the future trajectory of self-driving cars can significantly reduce the occurrence of traffic accidents. However, predicting the future trajectories of vehicles is a challenging task since it is influenced by the interaction behaviors of neighboring vehicles. This paper proposes a framework that allows for parameter sharing and cross-layer independence, based on a dynamic graph convolutional spatiotemporal network, to study the interactions between vehicles and the temporal dynamics in historical trajectories. By extracting dynamic adjacency matrices from different vehicle interaction features, the model can describe dynamic spatiotemporal relationships, enabling it to handle changes in traffic scenarios. Finally, the proposed model was experimentally compared with existing mainstream trajectory prediction methods using the NGSIM dataset. The results demonstrated that our trajectory prediction model achieved excellent performance in terms of model parameters and prediction accuracy. Compared to the four mainstream models, our model improved accuracy by 35.73%. In addition, we also analyze the relationship between model complexity and efficiency.
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Authors and Affiliations

Hao Chen
Xuncheng Wu
Ruoping Zhang
Wenfeng Guo
Yang Chen
Jiejie Xu
Weiwei Zhang
Wangpengfei Yu
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Abstract

In this paper, the problem of backward compatibility of active disturbance rejection control (ADRC) is investigated. The goal is to contextualize ADRC to deliver its interpretations from the established field of linear control systems. For this study, a control algorithm, denoted here as integral disturbance rejection control (IDRC), is considered that combines classical state-feedback control with an integral compensator. At first, an interpretation of ADRC is involved in terms of existing state-space control approaches. Next, a transition to the frequency domain is performed, which is justified as a significant part of practical control engineering is conducted in that domain. For assumed specific plant structures, both ADRC and IDRC are then holistically compared in terms of transfer function representation and frequency characteristics, as well as steady-state convergence conditions. Such a juxtaposition helps to highlight the similarities and differences of both approaches, whereas the utilized bandwidth parameterization is shown to bring the control system to the same form, thus indicating some interesting practical aspects. Finally, the theoretical results concerning both considered control structures are validated in a set of numerical simulations and experiments conducted on a laboratory hardware testbed.
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Authors and Affiliations

Mikołaj Mrotek
Jacek Michalski
Rafał Madonski
Dariusz Pazderski
Marek Retinger
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Abstract

In this paper, necessary and sufficient conditions for zeroing of the transfer matrices of descriptor continuous-time and discrete-time linear systems are established. The conditions are illustrated by simple numerical examples of the descriptor continuous-time and discrete-time linear systems. Also some remarks on the systems with delays on control are given.
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Authors and Affiliations

Tadeusz Kaczorek
1
ORCID: ORCID
Jerzy Klamka
2
ORCID: ORCID
Andrzej Dzieliński
3
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Electrical Engineering, ul. Wiejska 45D, Bialystok, Poland
  2. Polish Academy of Sciences, Institute of Theoretical and Applied Informatics, ul. Bałtycka 5, Gliwice, Poland
  3. Warsaw University of Technology, Faculty of Electrical Engineering, ul. Koszykowa 75, Warsaw, Poland
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Abstract

One of the methods for understanding residents' needs and socially improving urban spaces in terms of transportation, safety, landscape protection, and managing tourist traffic load is eye-tracking (ET). Researchers using mobile ET for outdoor studies face significant challenges, particularly due to sunlight affecting data quality. Existing solutions often overlook participant comfort. This article introduces a novel accessory designed for extreme lighting conditions, such as bright days, sunsets, and snowy or water-filled environments. The goal is to eliminate disruptions caused by uncontrolled sunlight on participants' eyes and enables studies in urban environments. A custom sun shield, designed for ETs based on spectacle frames, prioritizes both physical and psychological comfort. The lightweight shield is easy to install, minimally restricts the field of view, and does not interfere with eye-tracking components. It is cost-effective and suitable for DIY 3D printing. Control studies and field research confirmed its effectiveness, with feedback from over 100 users improving the final design. The shield enhances eye-tracking research credibility in sunny conditions, supports efficient calibration, and improves participant recruitment and well-being. Jakość danych znacząco wzrosła co obrazuje porównanie danych dotyczących sposobu detekcji źrenicy. Thanks to this solution, it will be possible to conduct research aimed at better understanding the behavior of city users, while ensuring their comfort and safety. It will also be possible to conduct research within the framework of so-called living labs. Importantly, studies show that the approach to designing subsequent mobile ETs based on IR should undergo significant modification.
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Authors and Affiliations

Marta Rusnak
Zofia Koszewicz
Franciszek Hackemer
Izabela Garaszczuk
Andrew T. Duchowski
Rafał Karnicki
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Abstract

The article presents a slip compensation method for traditional scalar (V/f) control of a five-phase induction motor. The proposed control method uses the possibility of injecting the third harmonic of voltage to increase the motor’s electromagnetic torque. The solution is characterized by both the simplicity of scalar control and improved speed control efficiency. The paper presents the PLECS simulation results and describes the laboratory tests that were conducted. The several scenarios were performed with dedicated and self developed algorithm in a laboratory stand using a 5-phase induction motor.
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Authors and Affiliations

Krzysztof Blecharz
ORCID: ORCID
Roland Ryndzionek
ORCID: ORCID
Paul Gondran
Imad Merzouk
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Abstract

A mobile ad hoc network (MANET) is a collection of mobile devices attached without infrastructure or central management. Network size increases rapidly, resulting in congestion, network delay, data packet loss, a drop in throughput, resulting in poor energy efficiency. Data should be mitigated based on the prediction of congestion. To resolve the problem of congestion, a novel Dragonfly Optimized Deep learning for conGestion Elimination (DODGE) technique has been proposed which predicts the congested node effectively. Initially, the Transmission Control Protocol (TCP), User Datagram Protocol (UDP) packets from the MANET environment has been pre-processed and the features are selected using Dragon Fly Optimization (DFO). The features that are selected from the DFO model has been provided to the Stacked Convolutional Neural Network combined with Bidirectional Long Short-Term Memory (SCNN-BiLSTM). The Deep Learning network will predict the congested node and if congestion is found, then the message will be displayed. The DODGE is simulated by using Network simulator2 (NS2) and a comparison is made between proposed DODGE and traditional approaches such as Hybrid Gravitational Fuzzy Neural Network (HGFNN), Quality of Service-Aware Distributed Congestion Control (QoS-ADCC), and ImprovedPriority Aware-Ad Hoc On-Demand Distance Vector (IPA-AODV) in terms of Packet Delivery Ratio (PDR), Delay (DE), Throughput (TP), Energy Consumption (EC), Latency (L), Detection Rate (DR), and Network Lifetime (NL). The proposed SCNN-BiLSTM improves the overall accuracy better than 10.05%, 6.59%, 3.26% Bidirectional Long ShortTerm Memory (BiLSTM), Deep Neural Network (DNN), Convolutional Neural Network (CNN) for predict the congested node in the shortest time.
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Authors and Affiliations

S Gladson
K Pandiarajan
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Abstract

The paper discusses a multilevel voltage source inverter with coupled reactors (MVSI-CR). The output voltage is generated using the novel coarsely quantized pulse amplitude modulation (CQ-PAM). The AC voltage synthesis is realized by selecting and applying an appropriate collection of voltage vectors from the space-vector diagram. Integrating classical two-level inverters allows achieving modularity of the solution. The main advantage of the proposed approach is a very low switching-to-fundamental frequency ratio and a multistep quasisinusoidal output voltage. The paper includes a theoretical analysis, simulations, and laboratory test results.
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Authors and Affiliations

Krzysztof Jakub Szwarc
Artur Cichowski
ORCID: ORCID
Paweł Szczepankowski
ORCID: ORCID
Janusz Nieznański
Ryszard Strzelecki
ORCID: ORCID
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Abstract

This paper presents the design of a laboratory stand that allows the study of the effects of exposure of magnetic induction of extremely low frequency on cultures of cancer cell lines. The designed laboratory bench, is adapted to operate in the frequency range up to 300 Hz and the maximum settable magnetic induction of 2.5 mT. Tests are carried out on cellular test plates of 24, 48 or 96 wells where it is possible to evaluate the combined effect of magnetic field and cisplatin on cancer cells. Tests were conducted to determine the uniformity of field distribution inside the constructed solenoid determining the optimal space for cellular research. Preliminary studies of the effect of the magnetic field on the response of cancer cells treated with cisplatin were carried out on the built stand. The study shows that a magnetic field with certain parameters can significantly affect the response of cancer cells to cisplatin treatment. The application of a magnetic field can either promote cell proliferation or, with appropriately selected parameters, lead to increased cytotoxicity. Continued research will allow us to determine the appropriate drug concentration parameters when using magnetic field exposure with given parameters.
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Authors and Affiliations

Remigiusz Mydlikowski
ORCID: ORCID
Krzysztof Maniak
ORCID: ORCID
Patrycja Grosman-Dziewiszek
Benita Wiatrak
Paweł Bieńkowski
Tomasz Gębarowski
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Abstract

Composite materials are defined as new materials formed by combining two or more materials that do not mix with each other, leveraging the best properties of each constituent. Composite materials are used in important industrial sectors such as aerospace and automotive due to their superior properties. In this study, XPS (extruded polystyrene) polymer foam was utilized as the core material. Glass fibers were combined with resin in a total of 8 and 12 layers, applied to both the top and bottom of the core structure. Production involved both manual laying and vacuum bagging methods. Two types of glass fiber, weighing 200 g/m2 and 300 g/m2 , were employed. After production, the composites were cut to standardized dimensions, followed by three-point bending and low-speed impact tests. Impact experiments were conducted with a constant energy of 50 J. Results showed that the 200 g/m2 glass fiber composites experienced perforation in the 8-layer samples and rebound in the 12-layer samples. Although greater deformation was observed in the impact tests of the 300 g/m2 glass fiber composites in the 8-layer samples compared to the 12-layer samples, rebound occurred in both. In three-point bending tests, the bending strength increased as the number of layers increased, and at the same number of layers, composites with 300 g/m² properties showed higher strength than 200 g/m² composites.
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Authors and Affiliations

Ibrahim Yavuz
ORCID: ORCID
Baris Senol
ORCID: ORCID
Ercan Simsir
ORCID: ORCID
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Abstract

The following paper deals with the multipole design of the switched reluctance motor (SRM). The design is intended to facilitate the four-channel operation of the motor. Due to multipole design of the rotor and multichannel operation abilities, there are numerous possible configurations for powering the poles in each phase. Analysis of selected such configurations was carried out, including multichannel (MC) operating conditions (e.g. single-channel operation (SCO)). A mathematical model of three-phase MC SRM is presented. The static electromagnetic torque characteristics were obtained together with the self- and mutual inductance characteristics. Selected laboratory test results are presented in the paper.
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Authors and Affiliations

Mariusz Korkosz
ORCID: ORCID
Piotr Bogusz
Jan Prokop
Piotr Zasowski
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Abstract

Drones have become common devices that are increasingly used, from toy mini-drones to very advanced autonomous flying platforms used in various industries. The safety of using engineering structures and the need to shorten the time of carrying out diagnostic activities, and thus reduce costs, force the use of innovative tools to carry out an automated and unmanned process of assessing the technical condition of existing engineering structures, especially large-size ones, including bridges strengthened with external FRP (Fibre Reinforced Polymer) composite overlays. There are conventional methods for assessing the technical condition of existing building structures carried out by inspectors and experts, involving the use of typical inspection and diagnostic tools. During the research, it was found that it is possible to carry out an automated and unmanned process of assessing the technical condition of engineering structures using an unmanned flying platform equipped with a thermal imaging diagnostic device. The uniqueness of the presented solution is that the drone is equipped with a docking module that allows the drone to be temporarily attached to the structure being diagnosed for the duration of diagnostic activities. To ensure appropriate conditions for structural diagnostics, a unique system of automated diagnostic process and a multi-stage structure of the control system in all phases of operation were developed. The article presents a solution for the control system based on control consistent with the reference model. In particular, the focus was on the difficult and dangerous issue of altitude control during the docking phase. Simulation tests carried out in the Matlab/Simulink environment, as well as laboratory and field tests on a real drone, proved the correctness of the proposed solutions, which enabled the undisturbed operation of the diagnostic module.
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Authors and Affiliations

Roman Czyba
Jarosław Domin
Marcin Górski
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Abstract

This article presents the technological problem related to the production of rotor with internal permanent magnet. Most often, the magnetic circuits of such rotors used in alternating current synchronous motors (AC IPM) are made of isotropic magnetic sheets. At this point, it should be noted that it is often not taken into account that each isotropic magnetic sheet exhibitssome anisotropy. This significantly affects the operational parameters of the brushless permanent magnet (PM) motor such as a cogging torque, electromagnetic torque ripples and an increase in induced voltage harmonics. To illustrate how important it is to properly design the rotor core, two rotors of the IPM motor were analysed in this work. In the first rotor solution, the minimisation of the anisotropy of the magnetic sheet was not taken into account, and the skew of the magnets was not used. In the second case of the IPM motor, the problem of anisotropy of the rotor magnetic circuit was minimised and an additional skew of the PMs was used. The obtained measurements and calculations of selected useful parameters of both rotor designs were compared with each other. Importantly, the conclusions and comments are extremely important for designers, assemblers and manufacturers of electrical machine components.
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Authors and Affiliations

Mariusz Korkosz
ORCID: ORCID
Adrian Młot
ORCID: ORCID
Elżbieta Sztajmec
Karol Ryłło
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Abstract

The design of responsive structures has evolved significantly, establishing itself as an interdisciplinary field characterized by a fully customized ideation process. To streamline and unify this process, a novel method for modeling the behavior of rod-like responsive structures using an evolutionary algorithm is introduced. The proposed mathematical framework leverages key geometric and physic parameters to control the generative process, enabling adaptability and fluidity in form development. By employing an evolutionary algorithm, the method offers an alternative to conventional rigid and repetitive morphing models, providing flexibility and innovation in responsive design outcomes. The developed model supports independent learning and fosters originality in solutions at both architectural and urban scales. Moreover, the presented methodology serves as the foundation upon which the authors developed the model, enabling its application across a wide spectrum of responsive structures for users. This paper addresses challenges in spatial modeling, behavioral algorithms, and the implementation of responsive architecture, presenting the author’s innovative model for rod-like responsive structures alongside performance analysis. The methodology demonstrates promising results in terms of adaptability and efficiency, with potential for further refinement to enhance speed and output quality. Research also describes challenges and risks for further development of responsive models implementation.
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Authors and Affiliations

Szymon Jankowski
Waldemar Bober
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Abstract

The paper states a complex study on the adaptive rescue cushion and concerns a problem of efficient impact mitigation, which is present during evacuation or assurance of people conducted by fire brigades. In order to minimize negative effects of person’s fall from height an airbag system is applied. Unfortunately, until now only passive solutions have been used. As a result, loads acting on a landing person were not minimized, because passive systems are designed for predefined, extreme conditions. Since the authors proposed to introduce adaptation mechanisms into the rescue cushion, a number of issues arose. They include construction and control of release vents, taking into account the inaccuracies of estimated impact parameters, and optimization of the venting area in case the evacuated person lands outside the airbag’s center. All these problems were addressed within this paper and described in detail. Discussion on the system adaptation and its optimization was preceded by experimental validation of a numerical model. The energy absorbing capabilities of widely used passive rescue cushions were significantly enhanced as a result of the conducted research.
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Authors and Affiliations

Rami Faraj
ORCID: ORCID
Błażej Popławski
Dorian Gabryel
Grzegorz Mikułowski
Rafał Wiszowaty
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Abstract

This paper describes research on a prototype of a multi-axis force and torque sensor dedicated to the support system of a telescopic camera crane arm. Based on studies conducted on an actual telescopic camera crane arm., the requirements that the sensor must meet to enable precise control of the drives in two working axes of the telescopic camera crane arm were defined. In the developed sensor, a method for measuring forces and torques using an optical displacement sensor was proposed. A simplified sensor prototype was made to verify the assumptions, and measurement tests were carried out. Additionally, the paper presents a CAD model of the sensor using an elastic pin, based on which a numerical model was developed, and calculations of displacements and mechanical stresses were performed.
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Authors and Affiliations

Paweł Młotek
Piotr Mynarek
Marcin Kowol
ORCID: ORCID
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Abstract

This paper presents a detailed study on the impact of temperature on the performance of a nonlinear electromagnetic vibration energy harvester, which is applied in autonomous power systems. The variability of material properties under the influence of temperature, such as stiffness, damping, and magnetic induction, significantly affects the operational characteristics of the device. A mathematical model accounting for these factors, including linear and quadratic temperature coefficients, optimized using a genetic algorithm, is presented in the article. The simulation results were compared with experimental data, showing good agreement, particularly in the range of frequency bandwidth and output voltage. It was demonstrated that higher temperatures lead to a reduction in mechanical and magnetic stiffness, resulting in decreased energy conversion efficiency.
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Authors and Affiliations

Marcin Kulik
Rafał Gabor
ORCID: ORCID
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Abstract

The fast algorithms of discrete sinusoidal transform of the fourth type (DST-IV) for small-length input data in the range of lengths from 2 to 9 are developed. Fast algorithms for short input data sequences are subsequently used as building blocks for designing fast algorithms of large-sized discrete transforms. Applying the fast DST-IV algorithms for small-size block processing can reduce overall system complexity and delay, allowing detailed signal processing. As a result of the literature review, two main approaches to developing fast discrete sine transform (DST) algorithms were identified, namely, the polynomial algebraic approach and the matrix factorization approach. In the paper, the last approach is exploited. A matrix-vector product expression of the DST-IV is the starting point for designing the fast algorithms. Then based on the repetition and arranging of the matrix elements, the factorization of the matrices of coefficients of DST-IV is produced to reduce computational complexity. The correctness of the obtained algorithmic solutions was justified theoretically using a strict mathematical background of each of them. The elaborated algorithms were then further tested using MATLAB R2023b software to finally confirm their performance. The resulting factorizations of the DST-IV matrices reduce the number of multiplications by 63% but increase the number of additions by 8% on average in the range of signal sample numbers from 3 to 9. It has been observed that for even-length input sequences, the reduction in the number of multiplications is not as significant as for odd-length sequences. For some other well-known discrete trigonometric transforms (discrete Fourier transform, discrete Hartley transform) the opposite situation holds. The proposed DST-IV fast algorithms do not limit the length of the input data sequence to powers of two or three. The data flow graphs constructed for the proposed algorithms reveal their modular space-time structure suitable for VLSI implementation.
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Authors and Affiliations

Marina Polyakova
Anna Witenberg
Aleksandr Cariov
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Abstract

In this paper, a university formula racing suspension is taken as the research object. Based on the requirements of acing suspension, the double wishbone suspension is improved, and a new arrangement scheme based on the stepped shaft is proposed, which theoretically realizes the decoupling of the pitch stiffness and the roll stiffness of the suspension. Based on ADAMS/Car module, the front and rear suspension models are established. By simulating the motion of formula racing, it is further judged whether the pitch and roll stiffness of the suspension are decoupled. According to this, the hard point coordinates of the suspension is adjusted to ensure that the length of each spring changes within the ideal range. Based on the optimized suspension, according to the national standard test method and the scoring standard of the automobile industry, combined with the university formula racing project, the vehicle handling stability test and scoring evaluation are carried out, and the vehicle handling stability is verified by the real vehicle test. A set of decoupling suspension is obtained, which can realize separate adjustment of pitch stiffness and roll stiffness and improve vehicle handling stability.
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Authors and Affiliations

Han Xu
Jiachuan Xu
Xuemin Cui
Yang Zhou
Xinyu Sun
Zongqi Wang
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Abstract

The widespread use of unmanned aerial vehicles (UAVs) has heightened the demand for effective UAV monitoring, particularly in protected areas. Current learning-based detection systems depend heavily on camera sensors’ ability to capture UAVs in surveillance areas; however, advanced camera control methods remain limited. This paper proposes determining multi-camera trajectories that maximize UAV capture probability, ensuring UAVs remain within the camera’s field of view for further analysis, such as detection methods from camera-shot images. For this purpose, stochastic modelling is considered in the control framework for optimizing surveillance camera trajectories to enhance the probability of capturing UAVs. Key control parameters are derived through classical probability evaluations of the model with maximizing the entropy and covering trajectory-based strategies are applied. The reliability of stochastic system modeling is empirically validated through comprehensive computational experiments. These findings demonstrate the model’s potential to enhance UAV capture rates through optimized camera trajectories and coverage efficiency, paving the way for future advancements in real-environment applications.
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Authors and Affiliations

Khishigjargal GONCHIGSUMLAA
Young Il Kim
Kun Min Yeo
Seong Hee Park
Yong Tae Lee

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